Control Method for Step Angle and Speed of Stepping Motor.
Stepper motor is a common type of motor with precise control and positioning capabilities. The control of the step angle and speed of a stepper motor is an important aspect of achieving its precise motion. This article will introduce the step angle and speed control methods of stepper motors, helping readers better understand and apply stepper motor technology.
Definition and significance of step angle
Step angle refers to the angle at which each step of a stepper motor rotates. It is one of the basic parameters of stepper motor control and an important indicator to measure the accuracy of stepper motor control. The size of the step angle determines the accuracy of each motion and position control of the stepper motor.
The size of the step angle depends on the structure and driving method of the stepper motor. Generally speaking, the smaller the step angle, the higher the motion accuracy of the stepper motor. Common step angles include 1.8 degrees, 0.9 degrees, and 0.45 degrees, among which 1.8 degrees is the most common standard step angle.
Control method of step angle
The control method of step angle can be achieved by changing the frequency and pulse number of the stepper motor drive signal. The following are several common step angle control methods:
1. Full step mode: In full step mode, each stepper motor pulse causes the stepper motor to rotate by one step angle. In this mode, the rotation of the stepper motor is relatively stable, but the relative accuracy is relatively low.
2. Half step mode: In half step mode, each stepper motor pulse causes the stepper motor to rotate by half a step angle. By switching between full step mode and immobility, higher resolution and smoother motion can be achieved.
3. Microstepping mode: Microstepping mode is a more advanced step angle control method. By changing the amplitude and phase of the driving signal, the stepper motor can move at a smaller angle, achieving higher accuracy and smooth motion. Common micro step modes include 1/2, 1/4, 1/8, 1/16, etc.
The selection of an appropriate step angle control method depends on the specific application requirements and accuracy requirements. In practical applications, it is necessary to select and configure according to the model of the stepper motor and the characteristics of the driver.
Speed control method
The speed control of a stepper motor is an important link in controlling the rotational speed of the stepper motor. The following are several common speed control methods:
1. Pulse frequency control: Control the speed by changing the pulse frequency of the stepper motor drive signal. Increasing the pulse frequency can increase the speed of the stepper motor, while reducing the pulse frequency can reduce the speed. This method is simple and feasible, but the range of speed adjustment is limited.
2. Voltage regulation control: Control the speed by adjusting the voltage of the stepper motor driver. Increasing the voltage can increase the speed, while decreasing the voltage can decrease the speed. This method can achieve a wide range of speed adjustment, but it requires high performance of the driver.
3. Closed loop control: Closed loop control is a more advanced speed control method that uses feedback devices such as encoders to monitor the actual speed of the stepper motor and make closed-loop adjustments based on the set target speed. This method can achieve more precise speed control and stability.
Choosing a suitable speed control method requires considering factors such as the characteristics of stepper motors, application requirements, and the complexity and cost of the control system.
The step angle and speed control method of a stepper motor is crucial for achieving precise motion control. The size of the step angle determines the motion accuracy of the stepper motor, and the speed control method can meet the speed requirements of different applications.
When selecting the step angle and speed control method for stepper motors, it is necessary to comprehensively consider factors such as application requirements, accuracy requirements, complexity and cost of the control system. Reasonable selection and configuration can maximize the performance of stepper motors, which are widely used in various application fields.
Analysis of the working principle of a stepper motor the interaction between magnetic field and current
Step motor is a precision control device widely used in automation systems, which achieves accurate position and speed control through the interaction of magnetic field and current. Below, we will analyze the working principle of a stepper motor and provide a detailed introduction to how the magnetic field and current interact to drive the motor to rotate.
Magnetic pole and magnetic field:
The rotor of a stepper motor usually contains multiple magnetic poles, which are made of permanent magnet materials or electromagnetic coils. When current passes through the coil in the motor, a magnetic field is generated. This magnetic field can be generated by a permanent magnet or by a coil excited by an electric current.
Coil and current:
The stator of a stepper motor usually contains multiple coils, which are connected to a power source and driven by current. The direction and magnitude of the current determine the strength and direction of the magnetic field. According to different control methods, the current can flow in one direction or in the opposite direction as needed.
Interaction between magnetic field and coil:
When current passes through the coil of a stepper motor, the magnetic field generated by the coil will interact with the magnetic field of the rotor. According to the principle of interaction, there is an attraction or repulsion force between the coil and the rotor, which causes the motor to rotate.
Magnetic field changes and rotor motion:
In a stepper motor, different magnetic field changes can be generated by changing the direction and magnitude of the coil current, thereby driving the rotor to move. For example, when the magnetic field of the coil is attracted to the magnetic field of the rotor, the motor will rotate to align the coil with the rotor. When the magnetic field of the coil repels the magnetic field of the rotor, the motor will rotate to move the coil away from the rotor.
In summary, the working principle of a stepper motor is based on the interaction between magnetic field and current. By controlling the direction and magnitude of coil current, stepper motors can achieve accurate position and speed control. The change in magnetic field drives the rotor to move, and different stepping angles and driving sequences determine the stepping mode of the motor. These principles and control methods make stepper motors a commonly used precision control device in automation systems, widely used in various industrial and commercial fields.
Application Cases of Stepping Motor in Automation Production.
With the rapid development of automation technology, stepper motors, as a precision positioning and control device, have been widely used in automated production. They improve the efficiency, flexibility, and accuracy of the production line through precise position control and stable motion performance. The following will introduce several application cases of stepper motors in automated production.
1. Automatic packaging machine: Automatic packaging machines typically require precise packaging operations based on the size and shape of different products. The stepper motor can drive conveyor belts, positioning robotic arms, and clamping devices to achieve accurate product positioning and packaging operations. By combining with an encoder, stepper motors can achieve high-precision positioning and motion control, improving packaging speed and quality.
2. Assembly line equipment: In automatic assembly lines, stepper motors are widely used for various positioning and assembly operations. For example, in mobile phone assembly production lines, stepper motors can be used to position screens, buttons, and other components to ensure accuracy and reliability of assembly. The precise control ability of stepper motors makes the assembly process more efficient and automated.
3. Automatic detection equipment: Automatic detection equipment requires precise positioning and testing of products to ensure product quality and consistency. A stepper motor can drive components such as conveyor belts, rotating platforms, or robotic arms to detect products according to predetermined routes and positions. The high-precision control ability of stepper motors makes the automatic detection process more accurate and reliable.
4. Automated warehousing systems: In the warehousing and logistics industry, automated warehousing systems can greatly improve the storage and handling efficiency of goods. Stepper motors are widely used as positioning and handling devices for shelves, achieving accurate storage and extraction of goods. By combining with encoders, stepper motors can achieve high-precision positioning and speed control, improving the automation level of storage systems.
5. 3D printer: 3D printers require high-precision positioning and material stacking to achieve complex 3D printing. Stepper motors are widely used on the XYZ axis of 3D printers, achieving high-precision printing results through precise position control and motion synchronization.
In short, stepper motors play an important role in automated production. They can provide precise position control and stable motion performance, meeting the requirements of automated production lines for high efficiency, flexibility, and accuracy. In application scenarios such as automatic packaging machines, assembly line equipment, automatic detection equipment, automated warehousing systems, and 3D printers, stepper motors play an important role in promoting the intelligent and automated development of production lines. With the continuous progress of technology, the breadth and depth of the application of stepper motors will continue to expand, bringing more innovation and improvement to automated production.
The Function of Stepping Motor Encoder and Its Application in Position Detection
A stepper motor encoder is a device used to measure the rotational position and speed of a motor. It usually consists of a photoelectric sensor and a rotating encoder disk. When the motor rotates, the encoder disk will rotate accordingly. The photoelectric sensor obtains rotational position information by detecting the engraved lines on the encoder disk. Stepper motor encoders are widely used in fields that require precise positioning and speed control. The following will introduce their application in position detection.
The stepper motor encoder plays a crucial role in position detection. It can provide accurate position feedback, enabling the system to know the current position of the motor. This is very important for applications that require precise positioning or motion control. The following are several application cases of stepper motor encoders in position detection:
Ⅰ. Robot motion control: In robot systems, stepper motor encoders are widely used to measure the rotation angle of robot joints in order to achieve precise position control. Robots can accurately perform various tasks, such as material handling, assembly operations, etc., based on the position information provided by the encoder.
Ⅱ. CNC machine tool: CNC machine tools need to achieve high-precision position control and cutting operations. The stepper motor encoder can provide accurate position feedback, enabling CNC machine tools to accurately position workpieces and control tool movement. This helps to improve machining accuracy and production efficiency.
Ⅲ. Medical equipment: In some medical devices, such as CT scanners, magnetic resonance imaging machines, etc., stepper motor encoders are used to locate and control the movement of the motor to ensure the accuracy of scanning or imaging. Medical equipment requires high accuracy in positioning, and stepper motor encoders can meet this requirement.
Ⅳ. Automated warehousing system: In automated warehousing systems, stepper motor encoders can be used to detect the position of shelves, thereby achieving accurate cargo storage and transportation. Through the position information provided by the encoder, the system can accurately control the movement of the motor, ensuring the accurate placement and extraction of goods.
In summary, stepper motor encoders play an important role in position detection. They can provide accurate position feedback, helping the system achieve precise positioning and motion control. Whether it is robot systems, CNC machine tools, medical equipment, or automated warehousing systems, stepper motor encoders play a crucial role in improving the accuracy, efficiency, and reliability of the system. With the continuous progress of technology, stepper motor encoders will continue to show more extensive and important application prospects in various fields.
The application status and prospects of stepper motors in household appliances and medical devices
As a precise position control motor, stepper motors are widely used in various fields. Among them, stepper motors are playing an increasingly important role in the home appliance and medical device industries.
Ⅰ. Application of stepper motors in household appliances
Household kitchen appliances: Stepper motors are commonly used in household kitchen appliances, such as mixers, bread makers, and coffee makers. By controlling the stepper motor, these appliances can achieve precise mixing, kneading, or stirring of coffee beans, providing higher performance and user experience.
Washing machine: Stepping motor is widely used in the mixer and drainage system of washing machines. They can control the rotation speed and direction of the mixer, as well as the flow rate and drainage time of the drainage system, in order to achieve more effective washing and drainage functions.
Air conditioning and heating: Stepper motors are used to control fans in air conditioning and heating, regulating indoor temperature uniformity. The precise control ability of the stepper motor can make the indoor temperature more stable and improve user comfort.
Ⅱ. Application of stepper motors in medical devices
Medical syringes: Stepping motors are widely used in medical syringes, especially automatic syringes. Through precise control of stepper motors, accurate drug dosage and injection speed can be achieved, providing safer and more effective medical services.
Surgical instruments: Stepping motors also have important applications in surgical instruments, such as surgical robots. By controlling the stepper motor, surgical instruments can achieve precise position control and motion path planning, improving surgical accuracy and safety.
Device movement and positioning: Stepper motors play a crucial role in the movement and positioning of medical devices. For example, scanners, X-ray machines, and nuclear magnetic resonance equipment use stepper motors to control the movement of moving platforms or rotating components, achieving precise image scanning and diagnostic functions.
With the continuous development of smart home and medical technology, the application prospects of stepper motors in household appliances and medical devices are very broad. The future development trends include:
Higher performance and accuracy: The stepper motor will continuously improve its performance to meet the increasingly high precision requirements. Higher resolution and faster response speed will become the direction of development.
Integrated design: Stepper motors will increasingly be integrated into the overall design of household appliances and medical devices. Through integrated design, size can be reduced, reliability can be improved, and production costs can be reduced.
Intelligent control: The stepper motor will be combined with an intelligent control system to achieve more intelligent and automated control. By combining sensors and feedback systems, stepper motors can achieve more accurate position control and adaptive control.
Stepper Motor Control Method: Pulse Signal Drive and Position Control
Stepper motor is a commonly used type of motor, and its precise position control characteristics make it widely used in the field of automation.
The control methods of stepper motors mainly include pulse signal drive and position control.
① Pulse signal driven control method
Pulse signal drive is one of the most basic control methods for stepper motors. It drives the stepper motor to rotate by sending a pulse signal. Each pulse signal triggers the motor to rotate by one step, thereby achieving a change in position. The pulse signal driven control method has the following characteristics:
Ⅰ.Easy to use: Pulse signal drive is a simple and intuitive control method. By determining the frequency and direction of the pulse signal, the rotation of the stepper motor can be easily controlled.
Ⅱ.High precision control: Pulse signal drive can achieve high-precision position control. By controlling the number and frequency of pulse signals, small positional changes can be achieved.
Ⅲ.Quick response: The stepper motor can quickly respond to the input pulse signal and rotate accordingly according to the changes in the signal.
The pulse signal driven control method is suitable for many application scenarios, such as:
Ⅰ.Robot motion control: Pulse signal drive can achieve precise motion control of robot joints, enabling them to perform complex tasks.
Ⅱ.Automated production line: Stepper motors can be used to drive conveyor belts, assembly machinery, and other equipment on automated production lines. The rotation of the stepper motors is controlled by pulse signals to achieve accurate positioning and transportation of products.
Ⅲ.Printing device: Pulse signal drive can be used to control the movement of the printing head in the printing device, achieving precise printing position.
② Position control method
In addition to pulse signal drive, another common method of stepper motor control is position control. Position control is achieved by determining the target position of the motor to control the stepper motor. The position control method has the following characteristics:
Ⅰ.High precision positioning: The position control method can achieve very precise position control. The current position of the motor can be detected through encoders or other sensors, and adjusted according to the set target position.
Ⅱ.Tracking control: The position control method can achieve tracking control of the motor. For example, in an autonomous navigation robot, position control methods can enable the robot to autonomously move along a predetermined path.
Ⅲ.Motion planning: Position control methods allow for planning and optimization of the motor's motion trajectory. By setting different target positions and speed curves, smooth and efficient motor motion can be achieved.
The position control method is widely used in the following application scenarios:
Ⅰ.CNC machine tool: By using position control methods, precise control of each axis on the CNC machine tool can be achieved, thereby achieving high-precision machining results.
Ⅱ.Robot navigation: Position control methods can enable robots to autonomously navigate in complex environments and achieve accurate target positioning.
Ⅲ.3D printing: The position control method can achieve precise 3D printing head movement, thereby achieving high-precision printing effects.
Pulse signal drive and position control are commonly used control methods for stepper motors. Pulse signal drive is simple and easy to use, suitable for applications that require precise position control; The position control method can achieve higher precision positioning and trajectory planning, and is suitable for applications that require precise tracking and navigation. According to specific application requirements, suitable control methods can be selected to drive stepper motors and achieve precise position control.
Analysis of the principle and working mode of stepper motors.
Stepper motor is a common type of motor that plays an important role in various application fields. It achieves precise position control by controlling the input pulse signal, which has the characteristics of precision, efficiency, and controllability. Below, we will delve into the principles and working methods of stepper motors.
The principle of a stepper motor is based on the interaction between magnetic field and current. A typical stepper motor consists of a stator, rotor, and encoder. The stator is composed of several magnetic poles, each of which is wound with a coil. The rotor is composed of permanent magnets, whose magnetism allows it to interact with the stator. Encoder is a device used to detect the rotational position of a motor.
The working mode of stepper motors can be divided into two types: single-phase and multiphase.
A single-phase stepper motor can rotate by inputting only one pulse signal. When a pulse signal is input, the magnetic field will cause the rotor to rotate, causing one step of rotation per pulse, thereby achieving a change in position. In single-phase stepper motors, the simplest type is a reversible magnetic field rotor stepper motor, which rotates the rotor according to a certain step size by changing the sequence of coil energization.
Multiphase stepper motors require pulse signals from multiple phases to drive. Similar to single-phase stepper motors, each pulse signal triggers one step of rotation. The difference is that multiphase stepper motors have higher control accuracy and speed. Multiphase stepper motors are usually composed of two, three, or four phases, with each phase having a coil and a certain phase difference between the coils. By sequentially activating different coils, the rotation of the stepper motor can be achieved.
Whether it is a single-phase or multiphase stepper motor, precise position changes can be achieved by controlling the frequency and direction of the pulse signal. This characteristic makes stepper motors widely used in many automation equipment, such as robots, CNC machine tools, printers, etc.
Prospects for the Application of Stepping Motors in New Energy Vehicles.
With the increasing global demand for environmental protection and sustainable development, new energy vehicles are gradually emerging as a significant alternative to traditional fuel-powered cars, becoming the dominant trend in the automotive industry. As a result, the application of stepper motors in the drive systems of new energy vehicles is gaining attention and importance. Stepper motors, known for their efficiency, precision, and strong controllability, have vast application prospects and offer numerous advantages to new energy vehicles.
Firstly, a key advantage of utilizing stepper motors in new energy vehicles is their excellent precision control capability. Stepper motors can achieve motion through accurate angle control, providing significant advantages in low-speed starting, driving stability, and parking. This high-precision control capability offers a smoother and more predictable driving experience, allowing drivers to easily manage the vehicle's movement.
Secondly, the digital control method of stepper motors improves the energy utilization of new energy vehicles. Through digital control, stepper motors can precisely drive according to the driving requirements, achieving efficient energy conversion. In comparison, traditional mechanical transmission systems in fuel-powered vehicles experience energy loss, whereas stepper motors reduce energy consumption while providing higher driving efficiency. This further enhances the driving range and energy utilization of new energy vehicles.
Additionally, the application of stepper motors in new energy vehicles provides flexibility and scalability. Stepper motors can be easily integrated into various drive systems, and their compact and lightweight characteristics make them an ideal choice for new energy vehicle drive systems that require minimal space and weight. This flexibility and scalability make stepper motors suitable for various types of new energy vehicles, including electric vehicles, hybrid vehicles, etc., providing automobile manufacturers with more choices and innovation possibilities.
However, there are still challenges in the application of stepper motors in new energy vehicles. Firstly, improvements in power density and durability are required. To meet the demands of electric vehicles during high-speed driving and long-term operation, stepper motors need to enhance their power density and durability to ensure consistent and stable driving performance. Secondly, the performance stability of stepper motors in high-temperature environments also needs further improvement to ensure reliability and safety under various complex driving conditions.
In conclusion, stepper motors have broad prospects in the field of new energy vehicles. Their precision control capability, high energy conversion efficiency, and flexibility provide significant driving force for the development of new energy vehicles. With continuous technological innovation and refinement, stepper motors are expected to play a more important role in new energy vehicles and make positive contributions to the further advancement of the automotive industry.
The Development Trend of Stepper Motor Drive Technology
With the continuous progress of technology, stepper motors, as a common motor driver, have been widely used in multiple fields. In recent years, stepper motor drive technology has undergone rapid development, continuously promoting the process of automation and intelligence.
Ⅰ High performance microstepping technology: Microstepping technology is an important development in stepper motor drive. By changing the current and pulse signals, a smaller step angle can be achieved, thereby improving the accuracy and smoothness of the stepper motor. In the future, high-performance micro stepper technology will continue to be improved, making the motion of stepper motors more delicate and precise.
Ⅱ High efficiency and low power consumption drives: With the increasing demand for energy conservation and environmental protection, stepper motor drive technology is also developing towards high efficiency and low power consumption. The new driver adopts advanced power electronic devices and control algorithms, which can achieve more efficient energy conversion and lower power consumption, improving the overall efficiency of the stepper motor system.
Ⅲ High speed and high torque control: Stepper motors are usually used in applications that require precise positioning and control, but their speed and torque are limited to some extent. To meet the needs of high-speed and high torque, stepper motor drive technology will continue to be improved. By optimizing driving algorithms, improving motor design, and adjusting magnetic field distribution, the maximum speed and output torque of stepper motors can be improved.
Ⅳ Intelligence and Networking: With the development of the Internet of Things and Industry 4.0, intelligence and networking have become the development trend of various industries. The stepper motor drive technology is no exception, and will be more integrated into intelligent control systems to achieve remote monitoring and data transmission. By connecting and collaborating with other devices, stepper motors can better adapt to complex working environments and automated production lines.
In summary, stepper motor drive technology is constantly developing towards high-performance micro stepping, high-efficiency low power consumption, high-speed high torque, and intelligent networking. These development trends will further expand the application scope of stepper motors, bringing more innovation and progress to fields such as industrial automation, intelligent transportation, and robotics.
Accuracy and Resolution Analysis of Stepper Motors
Stepper motors, as a commonly used actuator, play a crucial role in many industrial and consumer electronic devices. However, for many applications, accuracy and resolution are two key parameters of stepper motors that directly affect their performance and application effectiveness. In this article, we will analyze the accuracy and resolution of stepper motors and discuss their importance in practical applications.
1. Definition and Factors Affecting Accuracy
Accuracy refers to the degree of deviation between the predetermined position and the target position that a stepper motor achieves during motion execution, usually measured in angular or linear units. Accuracy is influenced by multiple factors, including the design of the motor itself, the stability of the drive system, load characteristics, and external environmental factors.
Firstly, the design and manufacturing quality of the stepper motor determine its internal structure and the precision of component fit. For example, the machining accuracy of the rotor, stator, and guiding components, as well as the quality of bearings, all have significant effects on accuracy.
Secondly, the stability of the drive system is crucial for accuracy. The drive mode, control algorithm, and quality of the driver used for the stepper motor can all affect its accuracy during motion execution. High-quality drivers and control systems typically provide more stable and precise motion control.
Lastly, load characteristics and external environmental factors can also impact accuracy. Factors such as unbalanced loads, external vibrations, or temperature changes may lead to a decrease in the accuracy of stepper motors.
2. Definition and Calculation Method of Resolution
Resolution refers to the smallest step angle or linear displacement that a stepper motor can achieve. In stepper motors, resolution is determined by the internal structure and driving mode.
For a single-step stepper motor, the resolution is usually expressed in step angles. For example, a stepper motor with a step angle of 1.8 degrees (or 200 steps/revolution) has a minimum resolution of 1.8 degrees/step, meaning that the motor can rotate in steps of 1.8 degrees.
For microstepping stepper motors, the resolution is higher. Microstepping is achieved by controlling the magnitude of phase currents and phase differences to achieve smaller step angles. For example, a stepper motor operating in 1/16 microstepping mode would have a resolution increased to 1.8 degrees/16 = 0.1125 degrees/step.
3. Relationship and Significance of Accuracy and Resolution
Accuracy and resolution are two important indicators of stepper motor performance, and they are closely related.
Accuracy determines the positioning accuracy of a stepper motor during motion execution, i.e., how accurately the motor can position the rotor or load to the target position. Resolution determines the smallest movement or angle change that the motor can achieve. Higher resolution means that the motor can achieve more precise control, thereby improving positioning accuracy.
For applications that require high accuracy, stepper motors with higher accuracy and finer resolution need to be selected. For example, precision instruments, medical equipment, and printing machinery typically require higher accuracy and resolution to ensure system accuracy and stability.
Additionally, accuracy and resolution also affect the dynamic response and motion smoothness of stepper motors. Higher accuracy and resolution can achieve smoother motion and lower vibrations, thereby improving the overall performance of the system.
In summary, the accuracy and resolution of stepper motors are important indicators for evaluating their performance and application scope. By selecting the appropriate stepper motor and optimizing the drive system based on specific application requirements, more accurate and stable motion control can be achieved, thereby improving the performance and efficiency of the equipment.
Different types of stepper motors and their application fields
When talking about stepper motors, we inevitably have to discuss the different types of stepper motors. Based on their structure, performance, and application, stepper motors can be divided into many types, such as single-phase stepper motors, two-phase stepper motors, three-phase stepper motors, four-phase stepper motors, etc. Each type of stepper motor has its unique application scenarios and advantages, and we'll explore them one by one.
1. Single-phase stepper motor
The single-phase stepper motor is the simplest type of stepper motor, typically consisting of two poles and a rotating rotor. Because of its simple structure, small size, and low cost, it is widely used in household appliances, home automation, medical equipment, handheld devices, and other fields.
2. Two-phase stepper motor
The two-phase stepper motor further optimizes the single-phase stepper motor, with its structure composed of two sets of electric drive coils that are orthogonally 90 degrees out of phase. With more precise current control, it can better control movement speed and accuracy and is commonly used in CNC machine tools, electronic watches, cameras, flatbed printers, and other equipment.
3. Three-phase stepper motor
The three-phase stepper motor has a more complex structure, consisting of three poles and a rotating rotor. It can maintain high precision while rotating at high speed, so it is often used in industrial automation, manufacturing, automotive accessories, and other application scenarios.
4. Four-phase stepper motor
The four-phase stepper motor is a high-performance stepper motor consisting of four electric drive coils. With more sophisticated structure and control than the three-phase stepper motor, it can achieve higher precision and speed and is suitable for high-demand application scenarios such as robots, printing presses, and CNC engraving machines.
In addition to the above four types of stepper motors, there are also more specialized types, such as linear stepper motors, flying gyroscope stepper motors, and motors for plasma-based applications.
Overall, different types of stepper motors have significant differences in application and performance, and choosing the right type of stepper motor based on specific requirements is crucial to meet the equipment's working requirements.
Common faults and troubleshooting methods of stepper motors.
Stepper motors are widely used in various types of equipment due to their high precision and low noise. However, as with any mechanical equipment, stepper motors are prone to malfunctions. In this article, we will discuss the common faults of stepper motors and their corresponding troubleshooting methods.
Overheating is a common fault in stepper motors, which may be caused by excessive current or poor heat dissipation. To solve this problem, you can adjust the current or use a better heat sink to improve heat dissipation.
Vibration is another common fault in stepper motors, which can lead to loss of precision or even damage to the equipment. This may be caused by an unbalanced load or abnormal motion control. To troubleshoot this issue, check the load balance and motion control system.
3. Loss of steps
Loss of steps means that the motor does not perform the expected number of steps, resulting in positioning errors or even system failure. This may be caused by insufficient torque, incorrect driving voltage, or mechanical jamming. To address this problem, increase the torque, adjust the driving voltage, or remove any mechanical obstructions.
4. Noisy operation
Noisy operation is a common problem for stepper motors, which may cause discomfort to users or disturb nearby equipment. This may be caused by poor motor quality, improper installation, or insufficient lubrication. To solve this problem, use high-quality motors, install them properly, and ensure proper lubrication.
5. Electrical faults
Electrical faults can occur due to problems in the power supply, control circuit, or wiring connections. Troubleshooting these issues requires a comprehensive understanding of the stepper motor control system and the ability to identify and repair faulty components.
In conclusion, stepper motors are prone to various malfunctions, but most issues can be addressed through proper troubleshooting and maintenance. By understanding the common faults of stepper motors and implementing appropriate measures, you can ensure the reliable and efficient operation of your equipment.
What are the control methods of stepper motors?
Stepper motors are a commonly used type of motor with advantages such as high precision, fast speed, and low noise, and are widely used in many applications. However, in order to fully exploit the performance of stepper motors, it is necessary to use suitable control methods for their control. This article will introduce the commonly used control methods for stepper motors.
1. Single-phase excitation control
Single-phase excitation control is one of the simplest control methods for stepper motors, which drives the motor rotation through a single channel of excitation. The advantage of single-phase excitation control is that the control circuit is simple and cost-effective. However, its disadvantage is also obvious, that is, the motor can only rotate in one direction and cannot achieve bidirectional rotation.
2. Bipolar excitation control
Bipolar excitation control is one of the most commonly used control methods for stepper motors. In bipolar excitation control, each phase of the motor is controlled through a separate channel. This control method can achieve forward and reverse rotation and higher precision than single-phase excitation control.
3. Microstep control
Microstep control controls the movement of stepper motors by applying small changes in current between each step pulse of the motor. This control method can achieve extremely high precision and smooth motion, but also requires more complex control circuits.
4. Vector control
Vector control is an advanced control method for stepper motors, which combines microstep control and rotor position detection to predict the next step position and apply the appropriate current to maximize the response speed and precision of the stepper motor.
In conclusion, the control methods for stepper motors include single-phase excitation control, bipolar excitation control, microstep control, and vector control, each with its own advantages and disadvantages. The appropriate control method should be chosen according to specific needs.
The practical value and application characteristics of stepper motors in stage lighting.
With the continuous development of technology, the application of stepper motors in stage lighting has become increasingly common. It can not only achieve precise lighting adjustment, but also improve the operational efficiency and reliability of stage equipment. Next, let's have a detailed understanding of the practical value and application characteristics of stepper motors in stage lighting.
1. Accurate positioning and control
The most crucial aspect in stage lighting is the positioning and control of the beam of light. When using a stepper motor to lift and rotate the lamp head, the direction and intensity of the beam can be more accurately controlled to meet the needs of different lighting effects.
2. Energy conservation and environmental protection
The stepper motor can adjust its power appropriately according to needs, thereby achieving effective energy utilization, saving energy, and reducing environmental pollution.
3. Wide applicability
Whether in small theaters or large performance venues, stepper motors can adapt well, making the control and operation of lighting equipment simpler and more efficient.
1. Precision motion control
The stepper motor has the characteristics of high precision, low noise, and accurate motion control, which enables stage lighting to achieve more accurate lighting effects and meet the needs of various stage performances.
The stepper motor has the characteristic of programmable control, which can customize control settings according to different needs and scenarios, better meeting the control needs of various complex stage lighting.
3. Toughness and durability
The stepper motor has the characteristics of strong wear resistance, good seismic performance, and long service life, which enables it to fully undertake the important task of motion control in the operating environment of stage lighting equipment.
In short, the application value of stepper motors in stage lighting equipment cannot be ignored. They provide precise, efficient, and reliable motion control methods, presenting more charming visual effects for various stage performances, and also providing great convenience for various artistic performances such as movies, television, and even evening etiquette.
Stepper Motor and Its Wide Application in CNC Machining
CNC (Computer Numeric Control) machining has revolutionized the manufacturing industry by providing fast, accurate, and precise results. One of the key components that make CNC machines so efficient is the stepper motor. But why are stepper motors so widely used in CNC machining?
Firstly, stepper motors are designed to provide precise and accurate movement control. They are able to move in small increments with high repeatability, which makes them ideal for CNC machines that require precise control over the cutting tools. This precision and accuracy allows for high-quality finished parts and reduces the need for post-processing.
Secondly, stepper motors are also able to operate at high speeds and can change direction quickly. This is particularly important in CNC machining where the cutting tool needs to move rapidly between different positions. Stepper motors have a high torque-to-inertia ratio, which means they can respond quickly to acceleration and deceleration commands, allowing them to achieve high speeds without sacrificing accuracy.
Thirdly, stepper motors are reliable and have a long operational lifespan. Unlike other types of motors, such as DC or AC motors, stepper motors do not have brushes or commutators that wear out over time. This means that with proper maintenance, stepper motors can last for years, making them a cost-effective solution for CNC machine builders and users.
Moreover, stepper motors are easy to control and integrate into CNC systems. They can be controlled by simple digital signals, which are easy to generate and transmit from the computer. This allows for precise and flexible control of the motor's speed, position, and direction, which is essential in CNC machining.
In conclusion, stepper motors are widely used in CNC machining due to their precise movement control, fast speed, reliability, and ease of integration. They are the backbone of CNC machines and play a critical role in achieving accurate and efficient results. As CNC machines continue to evolve, stepper motors will undoubtedly continue to play a central role in their design and implementation.
Classification and working principle of stepper motor drivers
Stepper motor drivers are electronic devices used to control the rotation of stepper motors by converting electrical pulse signals into the driving signals required by the motor. The classification and working principles of stepper motor drivers are as follows:
(1) Phase sequence type: Phase sequence type stepper motor drivers are a common driving method on the market. They control the rotation of the motor by controlling the current flowing through each phase winding. Common phase sequence drivers include single-phase drivers, two-phase drivers, and three-phase drivers.
(2) Micro-step type: Micro-step type stepper motor drivers can divide electrical pulse signals into any proportion, making the motor rotate more smoothly and improving the accuracy and control precision of the stepper motor. Common micro-step drivers include half-step, quarter-step, and eighth-step.
2. Working principle
The working principle of the stepper motor driver is to convert the current signal into the corresponding magnetic field to control the rotation and positioning of the motor. When current flows through the motor winding, a magnetic field is generated in the winding, attracting the permanent magnet in the motor, which drives the rotation of the shaft. By controlling the magnitude and direction of the current, the rotation direction and speed of the motor can be controlled.
Phase sequence stepper motor drivers typically control the rotation of the motor by controlling the current flowing through each phase winding. When the phase sequence driver receives an electrical pulse signal, it sequentially applies current to each phase winding according to the rotation direction and magnitude of the current, generating a magnetic field to control the motor's rotation.
Micro-step stepper motor drivers achieve more precise control by controlling the number of subdivided steps. In micro-step drivers, electrical pulse signals are divided into smaller signals to achieve smoother motor control. Micro-step drivers can also be subdivided according to the required number of steps to improve control precision.
In summary, stepper motor drivers are important electronic devices that convert electrical pulse signals into driving signals for precise control of stepper motors. They are widely used in mechanical, automation, and electronic control fields.
How to choose a suitable stepper motor?
If you are looking for a suitable stepper motor, you need to consider several key factors such as step angle, maximum torque, rotor inertia, matching driver and power supply voltage.
I. Step Angle
The step angle refers to the number of pulses required for a stepper motor to complete one step, usually between 0.9 degrees (200 steps/rev) and 1.8 degrees (100 steps/rev), where 1.8-degree step angles are more common. The smaller the step angle, the higher the precision and efficiency of the motor, but also the higher the price. Therefore, when choosing a stepper motor, it is necessary to determine the appropriate step angle according to the specific application scenario.
II. Maximum Torque
The maximum torque refers to the maximum output torque that the stepper motor can provide, usually expressed in N.m. The maximum torque depends on the magnetic flux inside the motor and the properties of the ferromagnetic material. A larger maximum torque usually means a greater load-carrying capacity of the motor, but also increases the complexity and cost of the motor.
III. Rotor Inertia
Rotor inertia is an important parameter that measures the dynamic response capability of the stepper motor, representing the size of the inertia during motor rotation, usually expressed in kgcm2. The smaller the rotor inertia, the stronger the acceleration and deceleration ability of the motor. For some high-demand application scenarios, such as 3D printing, CNC machines, etc., stepper motors with small rotor inertia should be selected.
IV. Matching Driver
In order to ensure the normal use of the stepper motor, a driver that matches its characteristics must be selected; otherwise, the motor may not operate normally. When purchasing a driver, it is necessary to consider factors such as the stop mode, control method, and power supply voltage of the driver.
V. Power Supply Voltage
The power supply voltage refers to the rated working voltage of the stepper motor, usually between 12V and 48V. The correct power supply voltage can ensure the safe and stable operation of the stepper motor. At the same time, it is necessary to pay attention to the maximum power supply voltage and protection level of the driver used by the stepper motor to prevent burns caused by excessive voltage.
In summary, choosing a suitable stepper motor requires considering the above factors comprehensively. For different application scenarios, it is necessary to choose according to actual needs and budgets.
Application and advantages of stepper motors in 3D printing
Stepper motors are a common type of motor that have been widely used in robotics, automation control, and 3D printing, among other fields. In 3D printing, stepper motors are crucial driving devices that finely control the movement and positioning of the printing platform and printhead. This article discusses the application and advantages of stepper motors in 3D printing.
I. Application of Stepper Motors in 3D Printing
Stepper motors are typically used to control the three-axis motion platform (X,Y, and Z-axis) and the movement and positioning of the printhead in 3D printers. Although the use of DC motors can achieve these motions, stepper motors are better suited for 3D printing due to the following reasons:
1. High accuracy: Stepper motors can precisely control the movement and positioning of the printing platform and printhead, ensuring the accuracy and quality of the printed products.
2. Reliability: Stepper motors use open-loop control, so they do not require feedback control devices such as encoders, making the system simple, stable, and reliable.
3. High homing accuracy: Stepper motors can stop accurately at a position after stopping motion, which enables good control of the printhead's homing point and avoids affecting the positional accuracy of the next print.
4. Easy control: Stepper motors are easy to control and can be started, stopped, or run at different speeds and directions by the controller. This characteristic makes stepper motors more versatile in their application in 3D printing.
II. Advantages of Stepper Motors in 3D Printing
Stepper motors have several advantages in 3D printing, including:
1. High precision: Stepper motors provide high-precision position control and dynamic response, ensuring the quality and accuracy of the printed products.
2. Easy to control: The control of stepper motors is simple, without complicated feedback control equipment, which facilitates the design and implementation of the printer control system.
3. Stable and reliable: Stepper motors have a simple structure and low failure rate because of their open-loop control, which enables the printer to work stably for a long time.
4. Low noise: The sound produced by the rotating stepper motor is low, making it suitable for indoor use and reducing interference with users.
In conclusion, stepper motors have wide application and superior performance in 3D printing. With continuous progress in manufacturing technology, control algorithms, and electronic hardware, the role and significance of stepper motors in 3D printing will continue to increase.
What is the positioning accuracy of the screw motor?
Screw motors are a common type of motion control device that are widely used in various automation equipment due to their simple structure, high precision, and strong load capacity. Among them, the positioning accuracy of screw motors is a very important indicator, and it is also an important evaluation criterion for their application fields and performance. Below, we will discuss in detail the topic of the positioning accuracy of screw motors.
The positioning accuracy of screw motors is mainly affected by multiple factors, among which the most critical are lead and pitch. Lead refers to the distance between two adjacent points on the helix, while pitch refers to the linear distance moved by the helix in one cycle.
Generally speaking, the smaller the lead, the smaller the distance moved per revolution, and the higher the positioning accuracy. Pitch determines the upper limit of the positioning accuracy that the screw can achieve in one pitch.
In addition to lead and pitch, compensation methods for errors are also important factors affecting the positioning accuracy of screw motors.
Error compensation methods are generally divided into open-loop control and closed-loop control. Open-loop control directly drives according to the input position command and cannot perform error correction, so the positioning accuracy is lower. Closed-loop control can monitor the current position in real-time through sensors and other devices, thereby performing feedback correction of errors and greatly improving positioning accuracy.
Moreover, control precision is also an important factor affecting the positioning accuracy of screw motors. Control precision depends on factors such as the drive circuit and control algorithm. If the drive circuit and control algorithm are well designed, then higher control precision can be achieved.
It should be noted that the positioning accuracy of screw motors will also be affected by some other factors in practical applications. For example, the quality of the mechanical structure, temperature changes, and the stability of the power supply voltage will all affect the positioning accuracy of screw motors to varying degrees.
In summary, the positioning accuracy of screw motors is a very important indicator that measures their performance. It determines whether screw motors can meet the control requirements of different application scenarios. When selecting and applying screw motors, it is necessary to choose appropriate lead, pitch, error compensation methods, and control precision parameters according to specific control requirements to achieve more efficient and stable motion control.
How to Avoid Step Motor Losing Steps？
Step motors are commonly used electric motors with high positioning accuracy, no feedback control required, and smooth torque characteristics. They are widely used in various industrial, commercial, and household equipment. In the process of using the step motor, losing steps is a common problem that needs attention to some details during selection, installation, and commissioning to avoid it.
1. Select Suitable Driver
Different types of motor drivers may provide different current and voltage values. Therefore, when selecting a motor driver, it is necessary to choose according to actual needs. If the current provided by the motor driver is too low, stepper motor losing steps is more likely to occur. Therefore, when selecting a motor driver, it is important to ensure that it can provide enough current and voltage to meet the torque and accuracy required for normal motor operation.
2. Set Reasonable Acceleration and Deceleration
In the control system, reasonable acceleration and deceleration need to be set. If the acceleration is too large or the deceleration is too fast, it will cause the motor to lose balance, vibrate or have losing steps. Therefore, the acceleration and deceleration should be increased or decreased gradually according to the specific motor model and mechanical load conditions to ensure normal motor operation.
3. Maintain Mechanical Load Balance
The mechanical load driven by the motor should be balanced as much as possible to prevent vibration or stepper motor losing steps caused by an imbalanced load. If an unbalanced load occurs, the mechanical device should be adjusted or repaired promptly to ensure normal motor operation.
4. Control Pulse Frequency
The frequency of control pulse should not be too high, and it should be set reasonably according to the specific motor model and mechanical load conditions. If the pulse frequency is too high, it is easy to cause the motor to lose balance and lead to losing steps. Therefore, the frequency of control pulse should be set according to actual needs.
5. Check Connections and Ensure Firmness
Regularly check whether the connections of the motor and sensor are firm to prevent losing steps caused by poor contact. At the same time, when installing the stepper motor, ensure that it is installed vertically to avoid unnecessary force on the motor.
In summary, if we pay attention to the above details, we can effectively avoid losing steps of the step motor. When using a step motor, reasonable control should be carried out according to the specific conditions to ensure normal motor operation.
Application Fields of PM Motors
PM motor is a kind of permanent magnet synchronous motor, which integrates permanent magnets on the rotor and is different from traditional induction motors. PM motors have advantages such as high efficiency, high starting torque, high precision, and low noise. They are widely used in many application fields, including:
Industrial production: PM motors can be used in various automation equipment, production line robots, and are widely used in automated production machinery, die-cutting machines, printing machines, packaging machines, textile machines, etc.
Transportation: PM motors can be used in the drive motors of electric cars, hybrid cars, electric bicycles, motorcycles, subways, and other transportation tools.
Household appliances: PM motors can be used in air conditioners, washing machines, refrigerators, disinfection cabinets, kitchen appliances, and other household appliances.
Medical: PM motors can be used in electric surgical knives, medical equipment, pharmaceutical equipment, and other medical fields.
Aerospace: PM motors can be used in satellite positioning systems, missile guidance, solar-powered aircraft, and other aerospace fields.
Peak current: the key parameter in controlling stepper motors
When it comes to controlling and driving stepper motors, peak current is a key parameter. Peak current refers to the maximum current value that appears in the current waveform during the motor operation. This value is an important parameter for the compatibility between the driver and the stepper motor, which can affect the performance and reliability of the system.
The magnitude of peak current is related to the characteristics of the stepper motor. Stepper motors usually have electrical parameters such as rated current, peak current, and holding current. The rated current refers to the current value required by the stepper motor during normal operation; the peak current refers to the maximum current value that the motor needs to withstand over a period of time; the holding current refers to the maximum current value that the motor can sustain for a long time. These parameters are crucial for selecting appropriate drivers and power supplies.
In practical applications, peak current is usually twice or more than the rated current of the stepper motor. This is because stepper motors need to bear large transient loads and impact loads during start-up and positioning processes. To ensure system stability and reliability, and to avoid motor damage or failure, drivers and power supplies that support peak current must be selected.
The selection of stepper motor's peak current is crucial in various applications such as machine tools, robots, and automated production lines. If the peak current is too small, the stepper motor may not be able to complete tasks such as start-up, positioning, and motion control. Conversely, if the peak current is too high, it will increase motor heating, reduce efficiency, and may cause equipment failures.
Therefore, choosing the right peak current for stepper motors is crucial. When selecting drivers and power supplies for stepper motors, it is necessary to carefully read the product manuals and data sheets, and understand their electrical parameters. Through proper design and configuration, the stepper motor system can maintain high-efficiency and stable operating conditions, thereby improving production efficiency and quality.
The development history of stepper motors.
1960s: The earliest implementation of stepper motor was achieved by changing the direction of the motor's electromagnetic poles. Subsequently, more sophisticated eddy-current type and magnetic field type stepper motors were developed, and the control methods of these stepper motors also gradually became more advanced.
1980s: With the continuous development of integrated circuit technology, the intelligence level of controller increased, and stepper motors began to be widely used. During this period, the performance and control methods of stepper motors continued to improve.
Early 21st century: With the continuous advancement of computer technology, the precision and efficiency of stepper motor control have been greatly improved. More types of stepper motors have been launched, such as two-phase, three-phase, five-phase, six-phase, etc., according to different application scenarios.
Future: With the rapid development of industry 4.0 and the Internet of Things, stepper motors will develop towards more intelligent, efficient, and networked directions. It is expected that stepper motors will further improve their control precision and efficiency, reduce costs and volumes, and provide more reliable and efficient services for industrial automation production.
In summary, stepper motors continue to meet people's needs for precision and efficiency through continuous development and innovation, and their application scope continues to expand. They will play an important role in broader fields.
What is the difference between a two-phase stepper motor and a three-phase stepper motor? What are the differences?
Stepping motors are generally composed of front and rear end covers, bearings, central shafts, rotor cores, stator cores, stator assemblies, corrugated washers, screws, and other parts, and are driven by coils wound around the motor stator slots. Typically, a wire wound in a circle is called a solenoid, while in a motor, the wire wound around the stator slots is called a winding, coil, or phase. The different number of coils inside the motor has become the origin of our common two-phase stepper motor and three-phase stepper motor.
So what is the difference between a two-phase stepper motor and a three-phase stepper motor? What are the differences?
1. Number of phases of the motor
As just introduced in the construction of a stepping motor, the number of coils inside the motor is different, and the number of phases of the motor is also different. The inside of a two-phase stepping motor is composed of two coils, while the inside of a three-phase stepping motor is composed of three coils.
2. Step angle of the motor
The step angle refers to the viewpoint of each step taken by the motor. Currently, there are two types of step angles for two-phase stepper motors on the market: 0.9 °/1.8 °, and 1.2 ° for three-phase stepper motors. It is particularly suitable for applications that require higher accuracy or require smoother and quieter operation.
3. Dimensions of the motor
Three-phase stepper motors are generally large motors, so their dimensions are generally larger than those of two-phase stepper motors. This has become the inherent advantage of three-phase stepper motors, which are smaller torque fluctuations and smoother operation. There are also drawbacks, which are that the size is larger than that of the two phases, and the application site is very limited. Therefore, the most common typical application in the field of stage lighting is that the spotlight needs to move quickly, while requiring quiet operation without affecting performance.
The torque of a two-phase stepper motor with the same scale will be slightly larger than the torque of a three-phase motor. Many people don't understand why two-phase stepper motors are larger than three-phase ones. That's because the 0.9 ° step angle is smaller than 1.2 °. Under the same operating speed of the motor, the pulse frequency applied to the 0.9 ° stepper motor must be more than one time that of 1.2 °, so the torque generated is slightly larger than that of 1.2 °. A typical application of the 0.9 ° stepper motor is security cameras, which can make the camera operate smoothly and accurately, Without causing the camera to shake, thereby causing blurring of the image.
Due to the different phase numbers, the corresponding stepper drivers are also different. The subdivision functions of two-phase stepper motor drivers are becoming more and more sophisticated, and this difference has been made very small. Two-phase stepping motors can also achieve the accuracy that three-phase stepping motors can achieve, and the torque in high-speed sections is also very close.
Professional terminology, dynamic indicators, and common parameter solutions for stepper motors
Professional terminology, dynamic indicators, and common parameter solutions for stepper motors
1. Step angle accuracy:
The error between the actual value and the theoretical value of the step angle for each revolution of the stepping motor. Expressed as a percentage: error/step angle * 100%. The value varies with the number of runs, and should be within 5% for four runs and within 15% for eight runs.
2. Out of step:
The number of steps a motor operates in is not equal to the theoretical number of steps. Call it a step out.
3. Misalignment angle:
The angle at which the axis of the rotor teeth deviates from the axis of the stator teeth, and there must be an misalignment angle in the operation of the motor. The error caused by the misalignment angle cannot be solved by using subdivision drive.
4. Maximum no-load starting frequency:
The maximum frequency at which a motor can be directly started without load under a certain driving form, voltage, and rated current.
5. Maximum no-load operating frequency:
The maximum rotational speed and frequency of a motor without load under a certain driving form, voltage, and rated current.
6. Operating torque frequency characteristics:
The curve of the relationship between the output torque and frequency measured during operation of a motor under certain test conditions is called the operating torque frequency characteristic, which is the most important of many dynamic curves of the motor and the fundamental basis for motor selection.
Other characteristics include inertial frequency characteristics, starting frequency characteristics, etc. Once the motor is selected, the static torque of the motor is determined, but the dynamic torque is not. The dynamic torque of the motor depends on the average current (not the static current) of the motor during operation. The greater the average current, the greater the output torque of the stepping motor, which means the harder the frequency characteristic of the motor.
Working principle of permanent magnet motor
Permanent magnet motor is a kind of motor that uses the magnetic field generated by permanent magnet to realize motor rotation. Permanent magnets usually use rare earth permanent magnetic materials, such as neodymium iron boron, cobalt boron, etc. These materials have the characteristics of high magnetic energy product and high coercivity, and can produce high intensity magnetic field.
The working principle of permanent magnet motor is based on Faraday's law of electromagnetic induction and Lorentz force principle. When the current passes through the coil of the permanent magnet motor, a magnetic field will be generated around the coil. This magnetic field will interact with the permanent magnet, making the permanent magnet subject to a certain torque,
thus generating rotation.
Specifically, in the permanent magnet motor, the permanent magnet is the main component that generates the magnetic field, and the coil is the part that generates the current. When the current passes through the coil, a magnetic field will be generated around the coil. This magnetic field will interact with the permanent magnet, so that the permanent magnet will receive a torque and start to rotate. The current direction in the coil and the magnetic field direction of the permanent magnet determine the torque direction of the permanent magnet, which makes the motor rotate.
Permanent magnet motor can be divided into permanent magnet synchronous motor, permanent magnet DC motor, permanent magnet stepper motor and other types, and its working principle and speed regulation mode are also different. The main characteristic of permanent magnet motor is that it does not need external excitation, so it has the advantages of simple structure, small size, light weight, etc., but also has the disadvantages of high cost and easy magnetization failure.
What is the relationship between the two? What's the role?
With the rapid development of the electrical machinery industry, the application of electrical machinery has gradually penetrated into all walks of life, which has brought great help to our production and life. Many friends are interested in electrical machinery, and are curious why it can be turned on? What is inside the motor?
What are the motor stator and rotor?
The internal part of the motor is mainly composed of two parts, the stator and the rotor, which I believe you have heard. The fixed part is called the stator, the rotating part is called the rotor, and the other parts are composed of the driver, end cover, fan blade, shell, etc.
What is the role of stator and rotor?
1. The main function of the stator is to generate magnetic field, which is composed of iron core, coil winding and base. The coils are distributed in the stator core, and when the current passes through, the induction electromotive force is generated, and the electric energy is converted.
2. The rotor is mainly composed of iron core, rotating shaft, winding, magnet, etc. As a part of the magnetic circuit of the motor, its main function is to induce electromotive force, generate electromagnetic torque from the current, and the rotating shaft is the main component that supports the weight of the rotor, transmits torque, and outputs mechanical power.
Strictly speaking, there are magnetic fields on the stator and rotor. The difference is that the rotor generates magnetism through electrical transformation and the stator generates electricity through magnetic transformation. Both are collectively referred to as armature magnetic fields. During the process of changing the phase sequence of the motor stator power supply, the stator magnetic field also changes and the motor keeps rotating.
What is the brake stepper motor?
The stepper motor is equipped with encoder, reducer and brake to improve the application range and performance of the motor, so what is the brake stepper motor?
The so-called brake stepper motor is to add a holding brake device to the tail of the stepper motor, that is, the brake device.
When the stepper motor is powered on, the holding brake is also powered on, and the brake device will also disengage from the output shaft of the stepper motor, so that the motor can operate normally. When the power is cut off, the brake release tightly holds the motor shaft. Realize the function of frequently starting and stopping a stepper motor to ensure that the motor is powered on or locked off.
What are the advantages of brake stepper motor and what industry is it widely used in?
For the stepper motor equipped with brake, the permanent magnet brake adopted has the characteristics of fast response, large retention force, long service life, etc. When the motor moves up and down, when the equipment is powered off, it can maintain the torque, so that the working object will not fall, which additionally improves the diversification of the use convenience of the stepper motor.
At present, it is widely used in dispensing machines, elevators, CNC machine tools, taper pullers, packaging machines and other automation equipment, because these industries often use start-stop devices when working.
How does the stepper motor driver work accurately?
Stepping motor is a special motor used for control. Its rotation is operated step by step at a fixed angle (called "step angle"). Its characteristic is that there is no accumulated error (accuracy is 100%), so it is widely used in various open-loop control.
The operation of the stepping motor needs to be driven by an electronic device. This device is the stepping motor driver. It converts the pulse signal sent by the control system into the angular displacement of the stepping motor. In other words, every pulse signal sent by the control system makes the stepping motor rotate a step angle through the driver. So the speed of stepping motor is proportional to the frequency of pulse signal. Therefore, controlling the frequency of step pulse signal can accurately adjust the speed of the motor; By controlling the number of step pulses, the motor can be accurately positioned.
Stepping motor is driven by subdivision driver, and its step angle becomes smaller. For example, when the driver works in 10 subdivision state, its step angle is only one tenth of the 'inherent step angle of the motor', that is to say, 'when the driver works in non-subdivision full step state, the control system sends a step pulse, and the motor rotates 1.8 °; When the subdivision driver works in 10 subdivision state, the motor only rotates 0.18 °, which is the basic concept of subdivision. The subdivision function is completely generated by the driver by precisely controlling the phase current of the motor, which is independent of the motor.
The main advantage of the subdivided driver is that it completely eliminates the low-frequency oscillation of the motor. Low-frequency oscillation is the inherent characteristic of stepping motor (especially reactive motor), and subdivision is the only way to eliminate it. If your stepping motor sometimes needs to work in the resonance area (such as arc walking), the subdivision driver is the only choice. The output torque of the motor is increased.
Difference between stepper motor and servo motor.
Various motors are needed in many fields, including well-known stepper motors and servo motors. However, for many users, they do not understand the main differences between the two motors, so they always do not know how to choose. So, what is the main difference between stepper motor and servo motor?
1. Working principle
The two types of motors are very different in principle. Stepping motor is an open-loop control element stepping motor that converts electric pulse signal into angular displacement or linear displacement. Check the working principle of stepping motor.
The servo mainly relies on pulses to locate. The servo motor itself has the function of sending pulses, so each time the servo motor rotates an angle, it will send out a corresponding number of pulses, so that it echoes with the pulses received by the servo motor, or called closed loop, so that the system will know how many pulses are sent and received back, so that it can accurately control the rotation of the motor and achieve accurate positioning.
2. Control accuracy
The accuracy of the stepping motor is generally achieved through the precise control of the step angle. The step angle has a variety of different subdivision gears, which can achieve precise control.
The control accuracy of the servo motor is guaranteed by the rotary encoder at the rear end of the motor shaft. Generally, the control accuracy of the servo motor is higher than that of the stepper motor.
3. Speed and overload capacity
The stepping motor is prone to low-frequency vibration when operating at low speed, so when the stepping motor is operating at low speed, damping technology is usually needed to overcome low-frequency vibration phenomenon, such as adding damper on the motor or adopting subdivision technology on the driver, while the servo motor does not have this phenomenon, and its closed-loop control characteristics determine its excellent performance when operating at high speed. They have different torque-frequency characteristics. Generally, the rated speed of servo motor is greater than that of stepping motor.
The output torque of the stepping motor will decrease with the increase of the speed, while the servo motor is constant torque output, so the stepping motor generally has no overload capacity, while the AC servo motor has strong overload capacity.
4. Operational performance
Stepping motor is generally open-loop control, which may cause out-of-step or locked-rotor phenomenon when the starting frequency is too high or the load is too large. Therefore, it is necessary to deal with the speed problem or increase the encoder closed-loop control to see what is closed-loop stepping motor. The servo motor adopts closed loop control, which is easier to control without out-of-step.
Stepping motors have advantages in cost performance. To achieve the same function, the price of servo motors is higher than that of stepping motors with the same power. The high response, high speed and high precision of servo motors determine the high price of products, which is inevitable.
To sum up, there are great differences between stepper motor and servo motor in terms of working principle, control accuracy, overload capacity, operation performance and cost. However, both have their advantages. If users want to choose from them, they need to combine their actual needs and application scenarios.
How to deal with the inertia mismatch of stepping motor?
Inertia mismatch is the difference between system inertia and stepping motor inertia. For machines operated by stepper motors, it is recommended to avoid large inertia mismatch. 1、 In addition to the inertia of the system it drives, the stepper motor itself also has the inertia that must be overcome. Second, friction further affects inertia. Third, too much torque from the oversized stepping motor will cause a series of problems.
Inertia mismatch greatly affects the operation mode of stepping motor. Due to the extremely mismatched inertia, the motor cannot accelerate and decelerate rapidly. If they have enough torque, but there is inertia mismatch, the load may not start or stop at the appropriate time or place. In the most extreme cases, inertia mismatch will lead to skip or stepping motor not working... as well as noise, vibration and heat.
There are several ways to deal with inertia mismatch. One is to simply adjust the size and matching of the motor and the load, and ensure that the inertia ratio of the load to the rotor is between 1:1 and 10:1 or close to this ratio... 3:1 is applicable to high-performance systems.
If this is not feasible for some reason, some techniques can be used to deal with excessive inertia mismatch. One way is to drive the motor through a long time of acceleration and deceleration, so that the motor will not miss the number of steps, and there will be no asynchronous situation. A warning: This will reduce efficiency and throughput, because it takes more time to reach full speed and full shutdown. One solution is to use a reasonably designed gearbox on the motor. This can solve the inertia mismatch problem, although it will introduce more design considerations and complexity.
How does the PLC control the stepping motor?
As an industrial control accounting machine, PLC has modular structure, flexible equipment, high-speed processing speed, accurate data processing ability, and excellent control ability of PLC for stepping motor. It can end the control of stepping motor by using its high-speed pulse output function or motion control function.
The characteristics of the stepping motor: (1) The angular displacement of the stepping motor is strictly proportional to the number of input pulses. There is no accumulated fault after the motor works for one week, and it has excellent following ability. (2) The open-loop digital control system composed of stepping motor and driver circuit is very simple, cheap and reliable. At the same time, it can also form a highly functional closed-loop digital control system with the viewpoint response link. (3) The dynamic care of stepping motor is fast, easy to start and stop, positive rotation and speed change. (4) The speed can be smoothly scheduled within an appropriate and wide plan, and the large torque can still be ensured at low speed. (5) The stepper motor can only be operated by pulse power supply. It cannot directly use communication power supply and DC power supply.
The highest stepping frequency that the stepping motor can take care of without losing step is called "claim frequency"; Similarly, "continuous frequency" refers to the highest step frequency at which the system control signal suddenly turns off and the stepping motor does not overshoot the direction. The claimed frequency, connecting frequency and output torque of the motor should be consistent with the rolling inertia of the load. With these data, you can effectively control the stepping motor with variable speed.
When PLC is selected to control the stepping motor, the pulse equivalent, the upper limit of pulse frequency and the maximum number of pulses shall be calculated according to the following formula, and then the PLC and its corresponding function module shall be selected. The frequency required for PLC high-speed pulse output can be determined according to the pulse frequency, and the bit width of PLC can be determined according to the number of pulses. Pulse equivalent=(step angle of stepping motor × Pitch)/(360 × Transmission speed ratio); Upper limit of pulse frequency=(moving speed × Stepper motor fraction)/pulse equivalent; Maximum number of pulses=(moving interval × Stepper motor fraction)/pulse equivalent.
PLC is selected to control the operation of stepping motor through stepping driver, and then PLC is used more and more widely in stepping electric control. For example, in the control process of single and double axis movement, set the parameters such as movement interval, speed and direction on the control panel. After reading these set values, the PLC will operate the stepper motor drive after calculating the pulse and direction signals to achieve the intention of controlling the interval, speed and direction. It has been proved by the actual measurement that the operation function of the system is reliable, feasible and useful.
What are the basic characteristics of stepping motor?
The following figure shows the relationship between torque and speed of stepping motor. The longitudinal axis is torque, and the transverse axis is pulse frequency. Pulse frequency refers to the frequency of driving pulse. In stepper motors, pulse frequency pps (pulses per second) is usually used instead of frequency Hz. The blue curve represents the "pull-in torque characteristic" of the stepping motor, and the yellow curve represents the "out-of-step torque characteristic" of the stepping motor.
Each feature is described in the following sections:
·Pull-in torque characteristics
"Traction torque characteristic", also known as "starting torque characteristic", refers to the relationship between the starting frequency (pulse frequency) of the stepper motor in the stopped state and the load torque. The area within the traction torque curve is called "self-starting area", which can be started, stopped and reversed. In addition, the frequency at which the load torque is zero=the limit frequency at which the stepping motor can be started is called the "maximum self-starting frequency". As shown in the figure, the higher the frequency, the lower the starting load torque.
·Pull-out torque characteristics
"Out-of-step torque characteristic" is also known as "continuous characteristic" or "pull-out torque characteristic". Indicates the frequency at which the rotation can continue when the load torque is increased after starting. Therefore, its value is higher than the value of the pull-in torque characteristic. The limit of continuous operation of stepping motor is called "maximum continuous operation frequency". Like the pull-in torque characteristic, the out-of-step torque characteristic is that the load torque will decrease with the increase of pulse frequency.
When the stepping motor is powered on, even if external force is applied when the stepping motor stops, the motor also tries to maintain the stop position through the attraction between the rotor and the stator. This holding force is called "holding torque". In the figure above, the working frequency (pulse frequency) is zero, which is the torque in the stop state.
By the way, the torque of the stepping motor decreases with the increase of the working frequency because the current is difficult to flow at high frequency due to the influence of the winding inductance.
In addition, the pull-in torque characteristics and out-of-step torque characteristics of the stepping motor will vary with the excitation method and drive circuit. Therefore, in the study of the characteristics of stepping motor, it is necessary to carry out the overall evaluation including the driving method and circuit.
·"Traction torque characteristic", also known as "starting torque characteristic", refers to the relationship between the starting frequency (pulse frequency) of the stepper motor in the stopped state and the load torque.
·The area within the traction torque curve is called "self-starting area", which can be started, stopped and reversed.
·The frequency at which the load torque is zero=the limit frequency at which the stepping motor can be started is called the "maximum self-starting frequency".
·"Out-of-step torque characteristic", also known as "continuous characteristic" or "pull-in torque characteristic", refers to the frequency that can continue to rotate when the load torque is increased after starting, and its value is higher than the value of pull-in torque characteristic.
·The limit of continuous operation of stepping motor is called "maximum continuous operation frequency".
·Both pull-in torque characteristic and out-of-step torque characteristic are that the load torque will decrease with the increase of pulse frequency.
·Holding torque is the force that the stepping motor tries to maintain the stop position even if external force is applied when the stepping motor stops under the power-on state.
·The pull-in torque characteristics and out-of-step torque characteristics of stepping motor will vary with the excitation method and drive circuit.
How to calculate the power of stepping motor?
Theoretically, the power of stepping motor can be calculated when it is running, but it is not scientific in terms of power overall. Because the power consumed by the motor changes when the control speed becomes faster or slower, each time point will generate voltage itself, and the voltage generated at different time points is not exactly the same. The voltage generated by the motor will offset the input voltage at the same time, so the calculated power is only at a certain moment, and cannot represent its whole. So, how to calculate the power of stepping motor, so we use torque to measure it.
Stepping motor is characterized by low torque, and the torque drops sharply after exceeding the rated speed. The relationship between the two is nonlinear. So for a stepper motor, the output power is different at different speeds. Therefore, we mainly refer to the parameter of torque when selecting models. If you must have a thorough understanding of how to calculate the power of stepping motor, you can refer to the following calculation method:
Torque and power are converted as follows: P=Ω · M, because Ω=2 π· n/60, P=2 π nM/60; P is power, unit is watt, Ω is angular velocity per second, unit is radian, n is rotational speed per minute, M is torque unit is newton meters.
Guide for selection of planetary reducer.
Planetary reducers are often used in the field of precision motion control due to their high torque, high torsional rigidity, low backlash and other characteristics. The application range is very wide, covering almost the entire automation field.
In the automation industry, as the second general mechanical equipment to be used, how to select the planetary reducer correctly becomes very important. Selecting a suitable reducer can provide greater torque, so as to achieve the best effect at the best speed, reduce the rotational inertia of the load, and increase the stability of the equipment. On the basis of meeting the applicability, the economy should also be considered. That is to say, the technical indicators of the planetary reducer can meet the requirements of the equipment and save costs. Both "over" and "under" will lead to cost waste. So how can we choose the "economical and practical" planetary reducer?
1. Determine the frame number according to the torque: the power source will have the effect of torque amplification after the reduction ratio. The output torque value of the reducer is proportional to the reduction ratio. The higher the ratio, the higher the torque value will be; However, the gear set of the reducer has limits, so the rated output torque of the planetary reducer means that the product can work stably under this data, so the box number must be selected according to the required torque.
2. Model depends on accuracy: positioning will be required in the automation process. When the positioning accuracy is higher, higher level products need to be selected, and vice versa. The precision of the planetary reducer is called "back clearance", which refers to the clearance of the gear set. It is defined as the angle value that the output shaft of the planetary reducer can rotate when the input end is fixed. The smaller the return clearance, the higher the accuracy and the higher the cost. Users can select the appropriate accuracy according to their actual situation.
3. Select according to the installation size: the size of the front end of the servo motor. The input end of the planetary reducer must match the size of the output end of the servo motor completely.
4. Select according to appearance: according to customer requirements, there are standard series of output shaft and connecting surface for users to choose from, or customized according to special needs of users.
5. Selection according to axial radial force: the life of planetary gear reducer is affected by the internal bearing, and the bearing life can be calculated by the load and speed. When the axial radial force load of the gear reducer is high, the bearing life will be shortened. At this time, it is recommended to select a higher grade product.
What controls the pulse frequency of the stepping motor? How to control the pulse frequency?
Due to its unique structure, the stepper motor is marked with "inherent step angle of the motor" when leaving the factory (for example, 0.9 °/1.8 °, which means that the angle of each step of half step operation is 0.9 °, and 1.8 ° for full step operation).
However, in many precision control and occasions, the angle of the whole step is too large, which affects the control accuracy, and the vibration is too large. Therefore, it is required to complete the inherent step angle of the motor in many steps, which is called subdivision drive. The electronic device that can achieve this function is called subdivision drive.
V=P* θ e÷360*m
5: Motor speed (r/s) P: pulse frequency (Hz) θ e: Inherent step angle of motor m: subdivision (full step is 1, half step is 2)
The rotation angle of the stepping motor is calculated independent of the signal frequency. The number of pulses is 10. The step angle of the stepping motor is 1.8 degrees. Then the stepping motor should rotate 18 degrees.
Pulse refers to a cycle of motor coil level from high to low, or from low to high. A few conversion cycles are several pulses, and the frequency is the number of conversions in a second, not the number of energizations in a second. If the frequency of the pulse signal sent by the plc is 50HZ, it means that the speed of the stepping motor to execute the number of pulses is 50 cycles within one second.
The pulse signal is the electric reading source of the stepping motor, which is characterized by discontinuity. Every time the stepping motor receives a pulse signal, it rotates at a certain angle. The controller sends a certain number of pulse signals, and the motor rotates at a certain angle. The high pulse frequency makes the motor rotate quickly. One is the total quantity, and the other is the quantity per second, which is the difference.
Step angle and coil group number of two-phase, three-phase and five-phase hybrid stepping motor
As we all know, stepping motor is an open-loop control element stepping motor that converts electrical pulse signal into angular displacement or linear displacement. In short, it is a device that makes objects produce relative angular displacement. By controlling the sequence, frequency and number of electrical pulses applied to the motor coil, the control of the direction, speed and rotation angle of the stepping motor can be realized.
However, when selecting a common type, it will be called two-phase, three-phase and five equal stepping motor. How is this called?
Stepper motors are generally composed of front and rear end covers, bearings, central shafts, rotor cores, stator cores, stator components, corrugated washers, screws and other parts, and are driven by coils wound on motor stator slots. Normally, a wire wound in a circle is called a solenoid, while in a motor, the wire wound on the stator slot is called a winding, coil, or phase.
According to the upper winding of the stator, there are two phase, three phase and five equal series. The most popular is the two-phase hybrid stepping motor, which accounts for more than 97% of the market share. The reason is that it has a high cost performance ratio, and it works well with subdivision drives. The basic step angle of this motor is 1.8 °/step. With a half step driver, the step angle is reduced to 0.9 °. With a subdivision driver, the step angle can be subdivided to 256 times (0.007 °/microstep). Due to friction and manufacturing accuracy, the actual control accuracy is slightly low. The same stepping motor can be equipped with different subdivided drivers to change the accuracy and effect. There are four phase four beat operation mode, namely AB-BC-CD-DA-AB, and four phase eight beat operation mode, namely A-AB-B-BC-C-CD-D-DA-A.
Two phase: 2 groups or 4 groups, step angle 1.8 °
Three phase: 3 groups, step angle 1.2 °
Five phases: 5 groups, step angle 0.72 °
The reason why the stepping motor only vibrates but does not rotate?
One of the reasons why the stepping motor only vibrates and does not rotate is that the wiring is wrong. The motor rotates forward and backward a little, and then it vibrates forward and backward. The reason why the stepping motor only vibrates but does not rotate is that the program is wrong. The program pulse is given too fast, and the motor cannot respond, so it has to follow the vibration.
Solution 1: Check the circuit if the stepping motor only vibrates and does not rotate. If it is the first wiring, be sure to confirm the phase line of the motor, or wire according to the drawing. When the stepper motor only vibrates and does not rotate, the driver wiring should not be connected incorrectly; If the stepping motor in use only vibrates and does not rotate, first check whether the motor circuit is damaged or disconnected. If it is disconnected, it will also cause the situation you said.
The second solution to the problem that the stepping motor only vibrates but does not rotate is to check the load. If the load is too heavy, the motor will be disconnected from the load for inspection.
Solution 3: Check the frequency of the input pulse. The input frequency of the stepping motor should not be too high. If it is too high, the motor will not rotate.
What is the reason why the stepping motor only vibrates and does not rotate? Another reason is that the take-off frequency is too high or the load is heavy, and the torque output by the motor is not enough.
Terminology related to stepper motor and screw motor
Positioning/residual torque: the torque required to rotate the output shaft of the motor when no current passes through the winding.
Holding torque: the torque required to rotate the output shaft of the motor when the winding is powered with steady DC.
Dynamic torque: under a certain step rate, the torque generated by the motor can generally be expressed by the pull in or pull out torque.
Pull in torque: the acceleration torque to overcome the rotor inertia, as well as the external load and various friction torques fixedly connected during acceleration. Therefore, the pull in moment is usually less than the pull out moment.
Pulling out torque: the maximum torque that the motor can produce at a constant speed. Since the velocity is constant, there is no moment of inertia. At the same time, the kinetic energy and inertial load inside the rotor increase the pull out torque.
Driver: an electrical control device used to run the stepping motor, including power supply, logic programmer, switch components and a variable frequency impulse source to determine the step rate.
Inertia: the inertial measurement value of an object for acceleration or deceleration, which is used for the inertia of the load to be moved by the motor or the inertia of the motor rotor.
Step angle: the rotation angle generated by each step of the rotor in the whole step
Step length: a linear stroke generated by the screw rod for each step angle of rotor rotation.
Pulse rate: the number of pulses per second applied to the motor winding, that is, the number of pulses per second pps.
Speed up and down: when the motor does not lose step, the given load increases from the original low step speed to the maximum, and then decreases from the original high step speed to the original speed.
Lead accuracy: the deviation between the actual position and the theoretical position obtained based on the lead.
Repetitive positioning accuracy: the deviation between the motor being commanded to the same target position under specific conditions.
Temperature rise: temperature rise is the temperature difference between the motor and the environment, which is caused by the heating of
the motor itself. During operation, the iron core of the motor will produce iron loss in the alternating magnetic field, and copper loss will occur
when the winding is energized, as well as other losses, which will increase the temperature of the motor. It is a very important index in motor design and operation.
Resolution: the linear distance generated when the motor receives a pulse in the whole step.
Resonance: Since the motor is an elastomer system, the stepping motor has a natural resonance frequency. When the step rate is equal to the natural frequency of the motor, resonance will occur, and the motor may produce audible noise changes, while the vibration increases. The resonance point will vary depending on the application and load, but it usually occurs at about 200pps. In serious cases, the motor may lose step near the oscillation point. Changing the step rate is the simplest way to avoid many problems related to resonance in the system. In addition, half step or micro step driving can usually reduce resonance problems. When accelerating or decelerating, it is necessary to cross the resonance area as quickly as possible.
How to realize forward and reverse rotation of stepping motor?
How is the forward and reverse rotation of the stepping motor realized, and what is the direction signal of the stepping motor? The direction level signal DIR is used to control the rotation direction of the stepping motor. This end is at the high level, and the motor rotates in one direction; This end is the low level, and the motor is the other steering. The motor commutation must be carried out after the motor stops, and the commutation signal must be sent after the end of the next CP pulse in the previous direction and before the next CP pulse in the next direction. When your controller (upper computer) sends double pulses (positive and negative pulses) or the amplitude of the pulse signal does not match, we need to use our signal module to convert it to 5v single pulse (pulse plus direction).
1. The dial switch input to the single pulse signal module should be turned to the "single pulse" position. The motor rotates when there is pulse output. The motor rotation direction can be changed by changing the high and low level of the direction signal. Refer to the signal module specification for specific timing.
2. The dial switch input to the dual pulse signal module should be turned to the "dual pulse" position. When a positive pulse is sent, the motor rotates forward; When a negative pulse is sent, the motor reverses. Positive and negative pulses cannot be given at the same time, and the specific timing can refer to the signal module specification. How to adjust the running direction of the stepping motor which is opposite to the requirements? There are two ways to achieve this: one is to change the direction signal of the control system. Another method is to change the direction by adjusting the wiring of the stepping motor. The specific method is as follows: For two-phase motors, just switch the motor line of one phase to the stepping motor driver, such as A+and A - exchange.
When will the stepping motor burn out ?
If you have used a stepping motor, you may have also encountered the phenomenon of motor burning. Although different motors are used, the probability of motor burning may be different, but it does not mean that the motor burning must be caused by its quality problems. Even to some extent, motor burning is very normal.
It can be said that the current stepping motor is easier to burn out than in the past, because with the continuous development of insulation technology, the design of the motor requires both increasing output and reducing volume, so that the thermal capacity of the new motor is becoming smaller and smaller, and the overload capacity is becoming weaker and weaker. In addition, with the improvement of production automation, the motor is required to operate frequently in a variety of ways, such as starting, braking, forward and reverse rotation and load changing, which puts forward higher requirements for motor protection devices. At the same time, the application of motor is more and more extensive, and it is often used in the humid, high temperature, dusty, corrosive and other harsh environments.
These conditions will lead to more damage to the stepper motor, especially increase the frequency of motor overload, short circuit, phase loss, bore sweeping and other faults, and naturally increase the probability of motor burning. It can even be said that motor burning is a relatively normal phenomenon in use, but the probability of motor burning is really smaller for high-quality motors.
When does the brake stepper motor need to be used?
I. Many motors are classified according to the working power supply
1. DC AC
2. Internal structure synchronous asynchronous or brushless with brush
3. Purpose drive control
II. What is a drive? What is control?
Drive: it means that the motor lock can drive the mechanism to move all the time, and the kinetic energy required to continue is called the drive motor
Speed regulating motor and three-phase asynchronous motor are usually used for large conveying. If we need greater output torque, we need speed reducing motor and variable frequency motor
Control: it is hoped that the motor lock driving mechanism can achieve multi position control and frequent stop, which is called control motor, such as stepping motor and servo motor
III. Understand the application of the motor, then analyze why the brake is used?
A lifting mechanism, such as screw rod and timing belt, is lifted with brake
When the speed is low, the torque increases, and when the speed is fast, the torque decreases
When the motor stops working and the power is cut off, how much torque do you need to rotate by hand to turn it, and this torque is called positioning torque
When the stepper motor is powered on, the torque of fast speed and slow speed is much larger than the positioning torque
When the motor works, it can take the mechanism to rise. When the motor stops, it cannot guarantee that the platform mechanism will not fall down. This is why we need to use the brake to lock and drag the shaft to position the height and accuracy of the platform
To sum up, for the stepper motor equipped with brake, the permanent magnet brake adopted has the characteristics of fast response, large holding force, long service life, etc. When the motor moves up and down, the torque can be maintained when the equipment is powered off, so that the working object will not fall, which further improves the diversity of easy use of the stepper motor.
What are the advantages of stepping motor? How to measure and verify the speed mode?
Have you known about stepping motors? What are the advantages? How to measure and verify the speed method? Now will give you a brief explanation, and I hope it will help you!
The principle of stepping motor is to convert the pulse signal into angular displacement or linear displacement. Its main advantages are as follows:
1. Good overload performance. Its speed will not be disturbed by the load size. Different from ordinary motors, when the load increases, the speed will decrease. Stepping motor has strict specifications for speed and position.
2. Easy to control. The stepping motor rotates in the unit of "step size", and the digital function is more obvious.
3. Simple structure of the whole machine. The traditional mechanical speed and position control structure is more complex and difficult to adjust. After using the stepping motor, the structure of the whole machine becomes simple and compact.
The speed measurement is that the motor converts the speed into voltage and transmits it to the input terminal as a feedback signal. The tachometer motor is an auxiliary motor, which is installed at the end of the ordinary DC motor. The generated voltage is fed back to the DC power supply to control the speed of the DC motor.
How are the stator and rotor products wound? What is the working principle and winding process of the winding machine?
The name of the winding machine indicates that it is used for winding, winding wire products to fixed objects, but here it mainly refers to the winding of stator rotor products, and the main wire is enamelled wire.
Give us a simple example! When 8090 was a child, my mother could knit sweaters. Many sweaters were fried dough twist shaped. It was very inconvenient to draw threads and knot easily when knitting sweaters. In order to solve this problem, fried dough twist shaped wool was usually wound into a wool ball, which would make knitting sweaters more convenient. This winding process is almost what the winding machine needs to do. How does the winding machine work?
The working principle of the winding machine is mainly related to the winding process. When the winding diagram of the stator and rotor is available, the corresponding winding program will be made. After being imported into the PLC system, it can be controlled. After the debugging is completed, it is a set of fully automatic processes. Press the start button, and the nozzle starts to operate with the wire. According to the winding program, the external winding machine generally uses the flying fork type winding, and the internal winding machine generally uses the upper and lower winding to complete the whole process, If problems occur during the period, you can pause or adjust the speed within the allowable range. It mainly includes three aspects: automatic wire laying, automatic winding and automatic transposition. When the wire is wound, the machine will automatically cut the wire, and then the product can be removed and replaced with a stator product. If other products need to be processed, the mold can be removed and the corresponding mold can be replaced. In this way, the reverse operation will form an assembly line mode, and the mass production of the stator and rotor can be realized.
With the continuous development and progress of science and technology, as well as the expansion of industrial demand, the traditional winding mode can no longer meet the winding demand of stator and rotor, and has been gradually replaced. The new fully automatic winding machine has begun to sweep the market and gradually applied to the winding of various industries. Such as: aircraft model motor, balance car motor, scooter motor, new energy vehicle motor, rotary transformer, fan stator, twisting car motor, radiator fan stator, plant protection machine, various outer winding stator, etc., or brushless motor winding of electric tools, water pumps, stepping motors, vacuum cleaner motors, gate gates, winches, etc.
It can be seen that the winding machine is widely used in many industries. However, in order to meet more demands and mass production, the winding machine still needs continuous improvement and development. I believe that the winding machine can be more powerful in the future!
How to make the stepping motor more environment-friendly and energy-saving in the process of use?
The environment is deteriorating and the air is being polluted. For each field, the most important thing is how to make the operation of products more environmentally friendly and energy-saving. The same is true for stepper motors. Although they are widely used, everyone hopes to make their use more environmentally friendly and energy-saving.
On the one hand, the speed of the frequency converter can be properly adjusted so that the motor can be used under the most energy-saving conditions. The production efficiency of the stepping motor has been improved to a certain extent, and the time required to run will be correspondingly reduced, so that a certain energy-saving effect can be achieved, and the service life of the motor will not be affected basically.
On the other hand, it is also through improving the production efficiency of the stepping motor to achieve its environmental protection and energy conservation, that is, to use high-efficiency stepping motor. Although this kind of motor is more expensive in price, its design is more reasonable, which can save a certain amount of energy consumption. Moreover, this kind of motor has a long service life. Combining these two points, the use of efficient motor can meet your needs more.
Therefore, if you want to make the stepping motor more environmentally friendly and energy-saving in the process of use, you can try from these aspects. It is hoped that these two methods can help everyone to use more green while obtaining efficiency.
How did electricity come from? What's the difference between DC and AC?
Electricity is a natural phenomenon. Static or moving charge will produce many interesting physical phenomena, such as lightning in thunderstorm weather, and the crackling sparks when taking off sweaters in winter. Later, scientists discovered laws from various electrical effects, and invented batteries, generators, and motors.
Why is the current divided into AC and DC? This is not a subjective division, but a division according to the characteristics of different currents. The earliest direct current was not generated by generators, but by batteries. In 1799, the physicist Volt made a galvanic cell out of salt water and tin zinc metal chips. There would be movement of electrons between the two gold metals, which produced direct current.
In 1801, the British chemist Humphrey Davy applied direct current to the platinum wire by using the method of galvanic cell, and the platinum wire gave off dazzling white light. Although the cost of this electric lamp was very high, and it was very easy to oxidize without inert gas protection, and it was scrapped in a few minutes, the prototype of the electric lamp had been born, and Edison had not been born that year.
Strictly speaking, Edison was not the first person to invent the electric lamp. Before Edison, about 20 people had invented the early electric lamp model. However, because the technology of vacuum pumping inside the electric lamp was not invented at that time, and the durability of the filament material still needs to be improved, commercial electric lamps have not been listed, and people can only use kerosene lamps.
When the technology became mature, Edison acquired patents and then promoted electric lamps to thousands of households, making himself famous. What does this have to do with direct current?
Edison built many DC power stations in the city in order to let residents use electric lights. In the early days, electric lights were powered by DC, which had a disadvantage. Assuming that Edison's DC power station is at position A, residents within a radius of 1km from position A can ensure normal power use, but the lights in residents' homes 1km away are often dim, because the 110V voltage generated by the DC generator is lost on the line after several kilometers of transportation, and the power to the user's home may be less than 60V. This is the disadvantage of DC power: it cannot be boosted, and power consumption is too much. But what could Edison do? The DC generators have been built. This problem occurs! So Edison built many power stations in the city to cover the city to solve this problem, which was also a helpless move.
When the shortcomings of direct current were exposed, alternating current began to rise.
The problem of power loss on the line was perfectly solved by combining alternating current with the transformer invented at that time. First, raise the voltage of 110V, and the current will decrease (P=UI) when the voltage rises. Then the thermal power generated on the circuit P=the square of the current multiplied by R will be much smaller than before. In other words, it is only necessary to build an AC power station in the city center, and then install transformers in each community to ensure the voltage stability. It is not necessary to build a DC power station in the city. So far, it is better to judge whether DC or AC is better.
Alternating current and direct current have their own characteristics. Some people, for example, say that alternating current is like a high-speed railway, while direct current is like an air plane, which can stop halfway and fly point-to-point.
At present, 220 V 50 Hz AC power is used for domestic use and 380 V for industrial use. In some countries, 110 V or 60 Hz AC is used for civil electricity. In addition to changing the voltage, sometimes the frequency of alternating current also needs to be changed. Usually, AC is converted into DC, and then DC is converted into AC of the required frequency.
Large electrical equipment generally uses AC power, while many household appliances and digital products in life use DC power although they are connected to AC power. In some circuits, both currents are used alternately. No one is more important than others, and each has its own use. Only when alternating current and direct current complement each other can we create a better life.
Application Advantages of Linear Screw Rod Stepping Motor in Machine Tools
The linear screw stepping motor drive technology can ensure a fairly high performance level and has higher simplicity than the traditional motor drive device that converts rotary motion into linear motion. Since the linear motor is directly connected to the moving load, there is no back clearance between the motor and the load, and the flexibility is very small.
The advantages of linear screw stepping motor in machine tool application are as follows:
1. The linear drive device can achieve a capacity of less than 1 μ M/s or speeds up to 5m/s. The linear drive system can ensure constant speed characteristics, and the speed deviation is better than ± 0.01%. In applications requiring higher acceleration, smaller linear screw stepping motors can easily provide an acceleration greater than 10g, while traditional motors generally generate an acceleration within the range of 1g.
2. The linear screw stepping motor has a simple structure and is composed of few components, so it requires less lubrication (the linear guide needs regular lubrication). This means that it has a long service life and runs cleanly. In contrast, the traditional drive system consists of more than 20 parts, including motor, coupling, ball screw, U-block, bearing, pillow block and lubrication system.
Other advantages of linear screw stepping motor include lower force and smaller velocity ripple, thus ensuring a more stable motion profile. Of course, it depends on the structure of the motor, magnetic plate and driving software. In order to take advantage of the inherent dynamic braking of linear screw stepping motor, the drive amplifier should effectively monitor the inverse electromotive force (EMF), even if the system power supply may be turned off. Multiple linear screw stepping motors can be installed in a "back to back" manner to ensure that the force is increased. Additional magnetic plates can also be added to ensure substantial unlimited travel (limited by feedback equipment and cable length) without loss of accuracy.
Operation of motor.
Preparation before motor startup
(1) In order to ensure the normal and safe starting of the motor, the following preparations shall be made before starting generally:
① Check whether the power supply has power and whether the voltage is normal. If the power supply voltage is too high or too low, it should not be started;
② Whether the starter is normal, such as whether the parts are damaged, whether the use is flexible, whether the contact is good, and whether the wiring is correct and firm;
③ Whether the specification and size of the fuse are appropriate, whether the installation is firm, and whether there is fusing or damage;
④ Whether the connector on the terminal block is loose or oxidized;
⑤ Check the transmission device, such as whether the belt is properly tightened, whether the connection is firm, and
whether the bolts and pins of the coupling are fastened;
⑥ Check whether the motor and starter housing are grounded, whether the grounding wire is open circuit, and whether the grounding bolt is loose or falling off;
⑦ Remove the sundries around the motor and remove the dust and oil dirt on the base surface;
⑧ Check whether the loading machine is properly prepared for startup.
(2) For motors that have not been used or stopped for a long time, in addition to the above preparations, the following items shall be checked before installation and startup:
① Check all data on the motor nameplate, such as power, voltage, speed, etc., to see if they are consistent with the actual use requirements;
② Check whether all parts of the motor are complete and well assembled;
③ Check whether the specification and capacity of the starting equipment are consistent with the requirements of the motor;
④ Use a 500V megger to measure the insulation resistance between motor phases and to the ground. The measured insulation resistance shall not be less than 0.5MQ. If it is less than 0.5M O, the motor must be dried or repaired before use;
⑤ Check the installation and calibration quality of the motor;
⑥ Check whether the motor connection is consistent with the nameplate;
⑦ The no-load operation shall be checked first to check whether the rotation direction is correct.
Precautions during startup
① After connecting the power supply, if the motor does not rotate, the power supply should be cut off immediately. Never hesitate to wait, let alone live check the motor fault, otherwise the motor will be burned and dangerous.
② During startup, pay attention to the working conditions of motor, transmission device and load machinery, as well as the indication of ammeter and voltmeter on the line. If there is any abnormal phenomenon, power off and check immediately, and start again after troubleshooting.
③ When starting the motor with manual compensator or manual star delta starter, pay special attention to the operation sequence. The handle must be pushed to the starting position first, and then connected to the running position after the motor speed is stable to prevent equipment and personal accidents caused by misoperation.
④ The motors on the same line shall not be started at the same time. Generally, they shall be started one by one from large to small to avoid simultaneous starting of multiple motors. The current on the line is too large, and the voltage drops too much, which will cause difficulty in starting the motor, cause line fault or make the switchgear switch.
⑤ When starting, if the rotation direction of the motor is reversed, the power supply shall be cut off immediately, and any two of the three-phase power lines shall be exchanged for each other to change the rotation direction of the motor.
Will the stepping motor lose excitation when disassembled?
In principle, common stepping motors can be divided into two types: reactive stepping motor and hybrid stepping motor. The reactive stepping motor can be disassembled, while the hybrid stepping motor must not be disassembled. Once disassembled, it will be a tragedy. The torque of the light ones will be doubled, and the heavy ones will be completely decorated. The mixed type mainly uses strong magnetic aluminum nickel cobalt material, which is high temperature resistant and does not demagnetize at high temperature. It is charged to saturated state during production. If it is disassembled, the magnetic circuit will no longer be closed, and the magnetic core will weaken. Special magnetizing equipment is required, which can not be solved by ordinary people. If neodymium iron boron material is used, it is not a big problem to disassemble it.
The rotor of the permanent magnet hybrid stepping motor (common 1.8 ° and 0.72 °) cannot be taken out, or it will be demagnetized. Unless you have a magnetizer to re magnetize. Once upon a time, I heard that when repairing a mechanical meter, the NS pole should be short circuited with soft iron after the magnet is taken out, so that the excitation will not be lost. However, this operation of the stepping motor is still a bit troublesome, after all, it is more precise.
If it is necessary to disassemble it, prepare a magnetic "short circuit" tool. In the same way, when disassembling the pointer multimeter, the magnetic circuit will be disassembled, resulting in a decrease in the magnetic density and the sensitivity of the meter head, resulting in a very large error. The magnetic "short circuit" method is also used to disassemble the multimeter. When the magnetic circuit must be disassembled, "magnetic short circuit" shall be carried out in advance, that is, the magnetic gap can be disassembled only when the soft iron material is laid on the two magnetic poles of the magnet to make the magnetic flux pass through the soft iron material without lowering. When installing it back, install the magnetic gap first, and then remove the "magnetic short circuit". However, sometimes "magnetic short circuit" is very difficult. For stepping motors, the inner diameter of the tool used for "magnetic short circuit" must be equal to the inner diameter of the motor stator, and only a few wire errors are allowed. It is difficult to process this tool even on a lathe.
The current permanent magnet hybrid stepping motor has small volume, large power, small magnetic circuit gap and only a few wires. It needs to prepare a magnetic "short circuit" device to fill the magnetic circuit gap, such as an iron cylinder with the same inner diameter as the stator (which can be loosely matched with the rotor gap). It is not a thin-walled iron cylinder with a wall thickness of at least 8-10mm. It is not to insert the ultra-thin iron cylinder into the gap, but to lean the cylinder end against the stator, make the cylinder and stator roughly concentric, and then move the rotor from the stator to the iron cylinder along the axial direction.
For the motor with a printed rotor once disassembled, a magnetizing coil is wound on the internal magnetic steel. Even demagnetization, if the torque margin of the motor itself is large, it will not affect the use. However, if the multimeter is used for accurate measurement, the error is obviously too large. All components using permanent magnetic materials, such as loudspeakers, pointer multimeter, permanent magnet motors... Unless absolutely necessary, do not disassemble the magnetic circuit, otherwise, "magnetism is weakened" and cannot be recovered.
What is switching power supply? What's the usage? What is the principle?
Operating principle of switching power supply
In the linear power supply, the power transistor is working, and the linear power supply is PWM switching power supply which leads to the closure or disconnection. In the two states of closure and disconnection, when the voltage of the power transistor is relatively small, a large current will be generated. When the switching power supply is closed, it is the reverse. The voltage is large, and the current will be particularly small. The controller that controls the working principle of the switching power supply, It is to better maintain stability, so as to bring safety to people's living environment.
Switching power supply working mode
As the name implies, switching power supply uses electronic switching devices (such as transistors, field effect transistors, silicon controlled thyristors, etc.).
Through the control circuit, the electronic switching devices can be continuously "turned on" and "turned off", and the electronic switching devices can pulse modulate the input voltage, so as to realize the DC/AC, DC/DC voltage conversion, and the output voltage can be adjusted and automatically stabilized.
Switching power supply generally has three working modes: fixed frequency and pulse width mode, fixed frequency and variable pulse width mode, and variable frequency and pulse width mode. The former mode is mostly used for DC/AC inverter power supply or DC/DC voltage conversion; The latter two working modes are mostly used for switching regulated power supply. In addition, the output voltage of switching power supply also has three working modes: direct output voltage mode, average output voltage mode and amplitude output voltage mode.
Similarly, the former working mode is mostly used for DC/AC inverter power supply or DC/DC voltage conversion; The latter two working modes are mostly used for switching regulated power supply.
According to the way switching devices are connected in the circuit, switching power supply can be generally divided into three categories: series switching power supply, parallel switching power supply, transformer switching power supply. Among them, transformer switching power supply (hereinafter referred to as transformer switching power supply) can be further divided into push-pull, half bridge, full bridge and other types; According to the excitation and output voltage phase of the transformer, it can be divided into forward, flyback, single and double excitation, etc; If divided from the purpose, it can also be divided into more categories.
Working principle and characteristics of stepping motor.
Principle: Stepping motor is a motor that converts pulse signal into linear displacement or angular displacement by using electromagnet principle. Every time an electric pulse comes, the motor rotates at an angle to drive the machine to move for a short distance.
The stepper motor driver controls the windings through the internal logic circuit and energizes them in the correct order, so as to realize the operation of the motor.
Taking two-phase 1.8 degree stepping motor as an example, there are mainly two methods: 4-wire bipolar and 6-wire unipolar:
4-wire bipolar motor
When the energizing direction of the winding changes in the sequence of ac ->bd ->ca ->db, the motor runs for one step (1.8 degrees) every time.
6-wire (unipolar) motor
When the energizing direction of the winding changes in the sequence of oa ->ob ->oc ->od, the motor runs for one step (1.8 degrees) every time.
Features: ① One pulse, one step angle.
② Control pulse frequency and electric speed.
③ Change the pulse sequence and the rotation direction.
④ The angular displacement or linear displacement is proportional to the number of electrical pulses.