Author: oliver4

1.Definition of integrated servo motor
Integrated servo motor‌ is a motor that integrates servo motor and driver. It has the characteristics of compact structure, easy installation and fast response speed. The integrated servo motor has a servo driver integrated inside it, which can directly receive signals from the controller and perform corresponding actions. Compared with traditional split servo motors, this design reduces the number of external connecting parts, further simplifying the installation and maintenance process of the system. In addition, due to the integrated design, the integrated servo motor also has significant advantages in performance, such as higher accuracy and faster response speed, thereby improving the overall performance and reliability of the system.

‌

2.Components of integrated servo motor
1.Motor part‌: including rotor, stator, windings, magnetic poles and other components. There are various types of motors, such as DC servo motors, AC servo motors, stepper servo motors, etc. Each type of motor is different in structure and control method.
2.Sensor part: usually includes position sensor, speed sensor, torque sensor, etc., which are used to detect the position, speed, torque and other parameters of the motor in real time, and feed the detection results back to the control system for real-time adjustment.
3.Controller part‌: Usually composed of a control chip, amplifier, encoder, etc., used to receive parameters fed back by sensors and output control signals to the motor to control and adjust the position, speed, torque and other parameters of the motor. .
4.Power supply part‌: Usually composed of power transformer, rectifier, filter, etc., used to provide stable power supply voltage and current to ensure the normal operation of the motor.
5.Mechanical part‌: Usually composed of reducers, couplings, transmission devices, etc., used to convert the rotational motion output by the motor into linear motion or other specific motion forms to meet different application requirements.

3.Operation mode of integrated servo motor
1.Position mode‌: This is the most commonly used control mode for servo motors. The host computer sends high-speed pulses of a certain frequency and cooperates with the direction signal to realize the forward and reverse rotation of the motor. By adjusting the frequency of the pulses, the speed of the servo motor can be changed. The core of the position mode is the position closed-loop control system, which consists of position sensors, controllers, drives and motors. It uses PID control algorithm to achieve precise control of the motor position by adjusting the proportional coefficient, integral coefficient and differential coefficient. Position mode is widely used in situations that require precise positioning, such as CNC machine tools, robot joints, automated assembly lines, etc.
2.Speed ​​mode‌: Speed ​​mode uses analog quantities to control the rotation speed of the motor. Although speed mode has fewer applications because it can control speed with the same accuracy as position mode, it still has its uses in certain specific applications. The core of speed mode is the speed closed-loop control system, which consists of speed sensor, controller, driver and motor. It also uses PID control algorithm to eliminate speed deviation and make the motor shaft run at a constant or changing speed.
3.Torque mode‌: Torque mode is usually used in constant voltage control to control the output torque of the servo motor through analog quantities. This mode is combined with the position mode for closed-loop control, and the effect is more ideal. The control of torque mode is more complicated, and it is necessary to detect the output current of the servo drive and perform torque control based on the current feedback signal.

4.Application scope of integrated servo motor
‌1.Industrial automation‌: Integrated servo motors play a vital role in the field of industrial automation and are widely used in robotic arms, conveyors, assembly lines and other equipment. They realize efficient production processes and improve production efficiency and product quality through precise position control and motion control. The fast response and precise position feedback capabilities of servo motors enable it to adapt to complex industrial environments and task requirements‌.
2.Robot technology‌: Servo motors are an ideal choice for robot joint drive. They can provide high-performance power output and flexible motion control to meet the different needs of robots in various industries, services and special environments. In fields such as automated production lines and logistics warehousing, servo motor-driven robots can achieve efficient operations and automation tasks‌.
3.CNC machine tools‌: Integrated servo motors are widely used in CNC machine tools, which can achieve precise motion control and position control, provide high-speed, high-precision working performance, and meet the needs of modern manufacturing for equipment automation and intelligence.
4.Medical equipment‌: Servo motors are widely used in various medical equipment, such as medical robots, imaging equipment, surgical instruments, etc. The high precision and reliability of servo motors play a vital role in medical equipment, ensuring the stability and safety of medical equipment‌.
5.Aerospace‌: In the field of aerospace, servo motors are widely used in the steering gear system of aircraft to achieve attitude control and flight stability of the aircraft by controlling the rudder surface of the aircraft. The rapid response capability and precise control capability of the servo motor enable the aircraft to achieve various complex flight movements, ensuring flight safety and stability‌2.

In addition, integrated servo motors are also used in medical equipment, 3D printing, textiles, printing and other industries. With the continuous development of technology, its application scenarios will continue to expand, providing more efficient and accurate solutions for various industries‌.

Source:https://www.steppernews.com/2024/08/operation-mode-of-integrated-servo-motor.html

1.Definition of five-phase stepper motors
A five-phase stepper motor is a motor powered by a five-phase AC power supply. Its structure is more complex than that of a four-phase stepper motor, and it can provide higher control accuracy and finer step lengths. This type of motor is usually used in application scenarios that require high-precision control, such as precision CNC machine tools, high-precision robots and other equipment. The working principle of a five-phase stepper motor is to control the power-on sequence of the five windings and the magnitude of the current to make the rotor produce different rotation angles, thereby achieving precise position control. Due to the high precision of the five-phase stepper motor, it has been widely used in high-precision automation equipment.

2.How to control the direction of the five-phase stepper motor
1.Change the direction of the current
The direction of the five-phase stepper motor can be achieved by changing the direction of the current. Usually, a five-phase stepper motor has two sets of coils, each with two pins, marked as A+, A- and B+, B-. If you want the motor to rotate clockwise, the current should enter the coil from A+ and B- and exit the coil from A- and B+; if you want the motor to rotate counterclockwise, the current should enter the coil from A- and B+ and exit the coil from A+ and B-.
2.Change the step sequence
Stepper motor control is actually controlling the step sequence of the motor. The step sequence of a five-phase stepper motor is AB-BC-CD-DE-EA. If you need to change the direction of the motor to the opposite direction, you need to change the step sequence. The method is to reverse the flow of current, that is, first energize the E and D coils, then energize the A and E coils, and so on.
3.Use a direction controller
If you don’t want to change the connection method or step sequence in the circuit, you can also use a direction controller to change the direction of the five-phase stepper motor. The direction controller can add a reversing switch at the input or output of the motor control signal. When you need to change the direction, just switch the switch.

3.Advantages of five-phase stepper motors
1.Smooth motion and high resolution: The five-phase stepper motor makes the rotation of the stepper motor smoother by introducing more phases, reduces vibration and noise, and improves the stability of the mechanical system. It can achieve a smaller step angle and improve the resolution of the stepper motor through microstepping, which is very useful for applications that require precise positioning and control.
2.Low speed and high torque: The five-phase stepper motor can provide higher output torque at low speed, which is very beneficial for some applications that require low speed and high torque output, such as medical equipment and precision instruments.
3.Reduce resonance and high-speed performance: At certain frequencies, stepper motors may resonate, resulting in unstable motion. Five-phase stepper motors can effectively reduce resonance and improve the smoothness of the system’s motion. At the same time, it can better control the motor at high speed and reduce the possibility of losing steps, which is very important for applications that require high-speed motion, such as printing presses and CNC machine tools. ‌
4.High efficiency: By better controlling the phase of the motor, the five-phase stepper motor can achieve the same output power at a lower current, thereby improving the energy efficiency of the system. ‌
5.Strong adaptability: The five-phase stepper motor driver is suitable for various stepper motors, including different types of motors such as bipolar, quadrupole and octapole, and has a wide range of applicability. ‌

4.Application fields of five-phase stepper motors
1.Automation equipment and instruments: The five-phase hybrid stepper motor is suitable for various small automation equipment and instruments, such as pneumatic marking machines, labeling machines, cutting machines, laser marking machines, plotters, engraving machines, CNC machine tools and pick-and-place devices. In these applications, the five-phase stepper motor can provide low vibration, low noise, high precision and high speed performance to meet user needs. ‌2.Precision CNC machine tools and high-precision robots: Due to its high-precision characteristics, the five-phase stepper motor is widely used in high-precision automation equipment such as precision CNC machine tools and high-precision robots. These devices have high requirements for precision and performance. Five-phase stepper motors can provide finer steps and higher control accuracy to ensure accurate operation of the equipment.
3.Industrial automation, machine tools, printing presses: Five-phase stepper drives are mainly used in industrial automation, machine tools, printing presses and other fields, with precise angle and speed control as the main features. These application areas require stepper motors to provide stable and reliable operation and precise position control.
4.Textile machinery and equipment: Stepper motors are widely used in textile machinery and equipment, such as computer embroidery machines. In particular, five-phase hybrid stepper motors use high-phase stepper motors to reduce step angles and improve control accuracy. They are suitable for applications with smooth operation, low noise, fast response and long service life.

5.Conclusion
As a special stepper motor, the five-phase stepper motor has the advantages of high precision, high efficiency and low noise. Its working principle, circuit structure and control method are different from those of traditional stepper motors, but its application range is wider. In the future, with the continuous advancement of science and technology and people’s increasing demand for high-precision intelligent equipment, five-phase stepper motors are expected to be used in more fields.

Source:https://www.steppernews.com/2024/08/application-fields-and-advantages-of.html

1.Definition
A variable reluctance stepper motor is a motor whose rotor is made of ferromagnetic material. When the stator is energized, it becomes an electromagnet and the rotor feels a pull in the specified direction. Ferromagnetic materials always try to adjust themselves in the path of minimum magnetic resistance. By energizing the coil, a magnetic field is generated and the air gap magnetic resistance is changed. This type of motor is called a variable reluctance stepper motor. In this type of motor, the direction of the motor is independent of the direction of the current in the winding. The rotor of a variable reluctance stepper motor (VR stepper motor) is made of soft magnetic material and has no permanent magnets. The stator coil generates a magnetic field that attracts the rotor teeth and causes the rotor to move step by step.

2.Common types of faults
1.Abnormal operation: This may be caused by improper driver parameter settings, poor connection between the motor and the driver, or motor failure. To solve this problem, you need to check whether the driver parameter settings are correct, whether the connection between the motor and the driver is good, and whether the motor is faulty.
2.Loss of step: This means that the actual position of the motor is inconsistent with the command position during operation. The reason for the loss of step may be due to excessive motor load, insufficient drive current, improper setting of the drive subdivision number, etc. The solution to this problem is to reduce the motor load, increase the drive current, adjust the drive subdivision number, etc.
3.Excessive noise: It may be caused by motor bearing wear, bad gears, poor connection between the motor and the drive, etc. In order to reduce noise, it is necessary to check the condition of the motor bearings and gears to ensure that they are in good working condition, and check whether the connection between the motor and the drive is good.
4.Heat: It may be caused by excessive motor load, excessive drive current, poor motor heat dissipation, etc. In order to avoid overheating of the motor, it is necessary to reduce the motor load, adjust the drive current, strengthen the heat dissipation of the motor, etc.

3.Maintenance and maintenance methods
1.Cleaning: Clean the stepper motor regularly to remove dust and dirt and keep the motor clean. Use vinegar or gasoline to wipe the inside and outside of the motor, and pay special attention to protect the motor from physical damage
2.Lubrication: Lubricate the bearings and other moving parts of the stepper motor regularly to reduce friction and wear. ‌ Use special lubricating oil or grease, and ensure that the bearings are fully lubricated. ‌
3.Parts replacement: Regularly check the parts of the stepper motor, such as the synchronous belt, gears and controller, and replace them in time if they are damaged or aged. ‌ It is recommended to use original accessories to avoid incompatibility issues that may be caused by using non-original parts. ‌
4.Storage conditions: If the stepper motor is not used for a long time, it should be stored in a dry, dust-free environment to prevent moisture and dust from damaging the motor. ‌ During storage, it is recommended to turn the motor regularly to ensure its flexibility. ‌
5.Regular operation: Even if it is not used frequently, the stepper motor should be run for a period of time regularly to maintain its performance and flexibility. ‌ This helps prevent the motor from degrading due to long-term non-use. ‌
6.Avoid overload: Make sure the load of the stepper motor is within the recommended range and avoid long-term overload operation to prevent overheating and damage to the motor. ‌
7.Professional operation: It is not recommended to repair or adjust the stepper motor by yourself unless you are an experienced technician. You should seek the help of professionals to ensure proper maintenance and extend the service life.

4.How to choose the right model

1.Torque selection: Choose the right motor model according to the required torque size (i.e. the torque size of the object to be driven). ‌ Generally speaking, if the torque is below 0.8N.m, you can choose 20, 28, 35, 39, 42 (the diameter or squareness of the motor body, unit: mm); if the torque is around 1N.m, it is more appropriate to choose a 57 motor; if the torque is several N.m or more, you should choose a stepper motor with specifications such as 86, 110, 130, etc. ‌2.Speed ​​selection: The output torque of the motor is inversely proportional to the speed. At low speed, the output torque of the motor is large; while at high speed, the torque will decrease. ‌ Choose the right motor according to the needs of the working environment. If a high-speed motor is required, a motor with a slightly smaller inductance should be selected to obtain a larger output torque.
3.No-load starting frequency selection: The no-load starting frequency of the stepper motor is an important indicator, especially in applications that require instantaneous frequent starting and stopping. If you need to start directly to achieve high-speed operation, you should choose a motor with a higher no-load starting frequency, such as a reactive or permanent magnet motor.
4.Phase number selection: Motors with different phase numbers have different working effects. The more phases, the smaller the step angle can be made, and the vibration during operation is relatively smaller. In most occasions, two-phase motors are used more. However, in high-speed and high-torque working environments, three-phase stepper motors are more practical.
5.Use environment: Select according to the use environment of the motor. For example, special stepper motors that are waterproof and oil-proof are suitable for some special occasions, such as underwater robots, etc.

 

1.Definition
The waterproof stepper motor is an electric device with waterproof function, suitable for various scenarios that require waterproof protection. ‌ It has the advantages of high reliability, wide adaptability and easy use. ‌ This motor can work normally in a specific environment, especially in an underwater environment, such as underwater robots and other applications, where waterproof motors are needed to ensure the normal operation and safety of the equipment. ‌

2.Design principle
The design principle of the waterproof stepper motor focuses on preventing moisture from invading and causing motor short circuit or failure. ‌ It adjusts the pressure change caused by temperature by forming a pressure regulating chamber, and adopts materials such as polyethylene insulation and nylon household waterproof electromagnetic wire. The cable connection method is based on cable joint technology. The joint insulation is removed from the scraped paint layer, welded firmly, and the raw rubber is wrapped around the layer to ensure waterproofing. ‌ The outer part of the motor is made of anti-corrosion material or anti-corrosion coating. Since the cracks or channels that may exist inside and outside the waterproof motor are blocked by the sealing mechanism, a reliable waterproof effect can be obtained. Even if the motor is watered for a long time, water will not enter the motor and cause a short circuit failure. ‌At the same time, the waterproof stepper motor also has certain explosion-proof performance.

3.Common faults and treatment methods
1.The motor cannot rotate: First, check whether the power supply is working properly, and use a multimeter or voltmeter to measure whether the voltage is stable. ‌If the power supply is normal, the fault may be caused by the driver or the motor itself. At this time, you can try to replace the driver or repair the motor. ‌

2.Unstable rotation or abnormal sound: This may be caused by incorrect configuration or parameter setting of the driver. ‌Check whether the parameters of the driver are correct. ‌If the parameters are correct, it may be that the internal components of the motor are damaged or the magnetic field is unstable. ‌It is necessary to repair or replace the internal components of the motor. ‌

3.Different or inaccurate rotation speed: Incorrect microstep setting may cause this problem. The correct microstep setting can be achieved by adjusting the parameters of the driver. ‌At the same time, check whether the external load is normal, because the external load may affect the rotation speed of the motor. ‌

4.Excessive heat: Excessive heat after long-term operation may be caused by overload or poor internal heat dissipation of the motor. ‌Check whether the load exceeds the rated operating range of the motor, and consider adding a cooling fan or heat sink to improve the heat dissipation effect. ‌

5.Loose core: During operation, if the core is loose, the motor should be stopped and tightened with tools. If the stator core is damaged, it should be replaced in time. ‌

6.Broken winding wire: The broken winding wire may be caused by abnormal vibration during the use of the motor. The damaged winding wire should be replaced in time. ‌

7.Broken and burnt winding joints: This may be caused by the quality of the motor itself or high-load operation. A motor of better quality should be selected and long-term high-load operation should be avoided. ‌
8.Loose brush slip ring: If the brush slip ring is found to be loose, the motor should be stopped and reinforced. ‌

1. Basic principles and characteristics of brushless DC motors

Brushless DC motors are high-efficiency, low-noise, high-torque, and low-power motors. The basic principle is to use the principle of electromagnetism to drive the motor by alternating the three-phase AC signals in the permanent magnet and the armature. Since the motor does not need to use brushes and commutators to achieve commutation, the impact of friction and wear on the motor performance can be avoided, thereby improving the reliability and life of the motor.

2. Application industries and related products of brushless DC motors
1. Electric vehicle industry
Brushless DC motors are widely used in transportation tools such as electric bicycles, electric motorcycles, and electric vehicles. Compared with traditional brushed DC motors and AC asynchronous motors, it has the characteristics of high efficiency, low noise, low vibration, low electromagnetic interference, and no commutation operation is required, so it is known as a “special motor for electric vehicles.”
2. Robot industry
Brushless DC motors are widely used in various types of robots, such as household robots, industrial robots, etc. The precision control and high-speed movement of robots require motors with high speed, high precision, and low inertia, and brushless DC motors are the ideal choice to meet these requirements.

3. UAV industry
Brushless DC motors are also widely used in the field of UAVs. The hovering and sharp turns of UAVs require high reaction speed and precision of the motor, and the high speed, high precision and low noise of brushless DC motors make it one of the mainstream motors for UAVs.
4. Industrial automation industry
Brushless DC motors are also widely used in various industrial automation fields, such as machine tools, stamping equipment, injection molding machines, etc. In these fields, precise control and high-speed movement of motors are also very important, so brushless DC motors are widely used.

3. Conclusion
The above is an introduction to the application industries and related products of brushless DC motors. Due to its advantages of high efficiency, low noise, and low electromagnetic interference, brushless DC motors are widely used in various fields and gradually replace traditional brushed DC motors and asynchronous AC motors.

1.Working principle

1.Two-phase stepper motors

Two-phase stepper motors refer to motors whose drive circuits have only two inputs, each of which controls a coil. When this motor rotates, one coil is activated first to generate a magnetic field, and then the other coil is activated to generate a magnetic field, thereby driving the motor to rotate. Two-phase stepper motors are usually simpler and easier to control, but because there are only two inputs, the step angle cannot be subdivided.

2.Four-phase stepper motors

Four-phase stepper motors refer to motors whose drive circuits have four inputs, each of which controls a coil. When this motor rotates, two coils are activated first to generate a magnetic field, and then the other two coils are activated to generate a magnetic field, thereby driving the motor to rotate. Since four-phase stepper motors have four inputs, they can be divided into smaller step angles, which are more precise than two-phase stepper motors.

 

2.Control method

1.Two-phase stepper motors

Since two-phase stepper motors have only two control inputs, their drive circuits are relatively simple, and only one H-bridge drive circuit is needed to control their operation. Among them, the H-bridge drive circuit is a circuit used to control the direction and size of the current, which consists of four switches. The size and order of the control current can determine the direction and speed of the motor rotation.

2.Four-phase stepper motor

Since the four-phase stepper motor has four inputs, it requires a more complex control circuit. It can be driven by an external controller such as a stepper motor controller or a microcontroller. In addition, since the four-phase stepper motor can be divided into smaller step angles, the requirements for the drive circuit are higher than those for the two-phase stepper motor.

3.Output efficiency

There are also differences in output efficiency between two-phase stepper motors and four-phase stepper motors. Since the step angle of the two-phase stepper motor is relatively large and the rotation speed is relatively slow, it is suitable for low-speed and low-precision applications. The four-phase stepper motor has a finer step angle and a faster rotation speed, which is suitable for high-speed and high-precision applications.

 

4.Application field

Two-phase stepper motors are mainly used to control low-speed and low-precision applications. If high-speed and high-precision control is required, four-phase stepper motors are usually used. Common applications include: electronic scales, printers, scanners, etc.

5.Conclusion

Although two-phase stepper motors and four-phase stepper motors both belong to the category of stepper motors, they have some differences in working principle, control method, output efficiency, etc. Understanding these differences can help readers better choose the type of motor suitable for their application field.

Source:https://www.steppernews.com/2024/07/the-difference-between-two-phase.html

1.Overview of three-phase stepper motor

The three-phase stepper motor is an actuator that converts electrical pulse signals into angular displacement. It has the advantages of simple structure, convenient control, high precision, and no cumulative error. It is widely used in automation equipment such as CNC machine tools, robots, printers, scanners, etc.

 

2.Speed ​​regulation principle of three-phase stepper motor

Speed ​​regulation refers to changing the speed of the motor to meet different working requirements. The speed regulation of three-phase stepper motors is mainly achieved in the following two ways:

1.Pulse frequency speed regulation: By changing the pulse frequency input to the motor driver, the speed of the motor can be changed. The higher the pulse frequency, the faster the motor speed.

2.Current control speed regulation: By adjusting the current in the motor winding, the torque of the motor can be changed, thereby affecting the speed. The larger the current, the greater the torque and the faster the speed.

3.Speed ​​regulation method of three-phase stepper motor

1.Microstep control: By subdividing the step angle of the motor, more precise control can be achieved. For example, subdividing the step angle of 1.8 degrees into 0.9 degrees can improve control accuracy and smoothness.

2.PWM control: Use pulse width modulation (PWM) technology to adjust the current size in the motor winding to achieve smooth speed regulation.

3.Vector control: By controlling the direction and size of the motor’s magnetic field, efficient and accurate speed regulation is achieved.

4.Current chopping control: By adjusting the on and off time of the current, the motor speed is controlled.

5.Hybrid control: Combine the above control methods to achieve better speed regulation performance.

 

4.Implementation steps of three-phase stepper motor speed regulation

1.Determine the speed regulation requirements: According to the application scenario, determine the required speed regulation range and accuracy.

2.Select a suitable driver: According to the motor parameters and speed regulation requirements, select a suitable stepper motor driver.

3.Design control circuit: Design a suitable control circuit to achieve control of the motor driver.

4.Write a control program: According to the control requirements, write a control program to achieve precise control of the motor.

5.Debug and optimize: Through actual operation, debug and optimize the control parameters to achieve the best speed regulation effect.

Three-phase stepper motor speed regulation technology has a wide range of applications and prospects in the field of automation. By choosing the appropriate speed regulation method and control strategy, the motor can be precisely controlled to meet the needs of different scenarios. With the continuous advancement of control technology, the speed regulation performance of three-phase stepper motors will be further improved, providing a stronger driving force for the development of automation equipment.

Source:https://www.steppernews.com/2024/07/how-to-realize-speed-regulation-of.html

 

 

1.Introduction
Linear stepper motor is a commonly used precision motion control device, which is used to realize linear motion control of various mechanical equipment, such as printing equipment, cutting equipment, medical equipment, 3D printers, etc. Correct selection of linear stepper motor is one of the key factors to realize motion control of these equipment. The following describes how to select a suitable linear stepper motor according to the application scenario and performance requirements.

2.Motor parameters
1.Load quality: Linear stepper motor needs load when working, so it is necessary to select an appropriate motor according to the load quality. Generally, it is necessary to ensure that the maximum value of the load under normal working conditions of the motor is within the rated load range of the motor.
2.Drive voltage: The motor drive requires a certain voltage. When selecting, it is necessary to select the motor according to the voltage situation, and generally select the highest voltage within the motor voltage range.
3.Step angle: The step angle is an important parameter when controlling the motor, and it needs to be determined according to the step angle when selecting.
4.Number of steps: The larger the number of motor steps, the higher the corresponding position control accuracy.

3.Driving mode
1.Open-loop control: Open-loop control means that the linear stepper motor has no position feedback mechanism, so the movement accuracy cannot be guaranteed during control.
2.Closed-loop control: Closed-loop control ensures the accuracy of motor movement through position feedback mechanism. When choosing closed-loop control, you need to choose a position feedback device with sufficient accuracy, such as photoelectric encoder, magnetic encoder, etc.

4.Control mode
1.Pulse/direction control: Pulse/direction control controls the motor movement by generating pulse signals, which is suitable for slower motion control.
2.Step/direction control: Step/direction control achieves high-precision motion control by controlling the distance the motor moves each step.

5.Conclusion
In summary, choosing a suitable linear stepper motor according to the application scenario and performance requirements requires considering factors such as motor parameters, drive mode, and control mode. Correctly selecting a motor can ensure the normal operation and control accuracy of the equipment.

Source:https://steppermotor.pixnet.net/blog/post/154804873

 

1.Structural differences
The rotor of an internal rotor motor is assembled inside the motor housing and connected to the motor’s output shaft. The rotor of an external rotor motor is located outside the motor, and the output shaft is also transmitted by the rotation of the rotor outside the motor.

2.Differences in characteristics
1.Internal rotor motors are usually more compact and have higher power density because the motor components are more compact. External rotor motors are usually easier to maintain because the rotor components are outside the motor and are easy to maintain and replace.
2.Internal rotor motors can withstand higher pressures and torques because their rotors are more secure inside the motor. However, external rotor motors can rotate faster because their rotors are lighter.
3.Internal rotor motors tend to have longer life and higher efficiency than external rotor motors. This is because the rotor runs inside the motor and is not affected by external physical factors. The centripetal force and other physical phenomena generated by the external rotor motor when rotating at high speed may reduce the motor efficiency and life.

3.Application differences
Internal rotor motors are often used in high-performance applications such as aircraft, rockets, high-speed trains, etc. This is because internal rotor motors have higher power density and can provide greater output power. External rotor motors are usually used in smaller applications, such as household appliances, small machinery, etc. This is because they are easier to maintain and replace and have better reliability.

4.Summary
Both internal rotor motors and external rotor motors are important types of motors. According to different application environments and requirements, you can choose the appropriate motor type. Internal rotor motors are suitable for high-load and high-performance applications, while external rotor motors are suitable for smaller and simpler applications. In addition, internal rotor motors usually have higher efficiency and longer life, but external rotor motors are easier to maintain and replace.

The linear stepper motor is generated by the interaction between the magnetic rotor core and the pulsed electromagnetic field generated by the stator. The linear stepper motor converts the rotary motion into linear motion inside the motor. But how to select the linear stepper motor? You can refer to the operating parameters of the motor

The following are the commonly used parameters of linear stepper motors
1.Maximum speed: The maximum operating speed under the determined power supply line voltage, depends on the number of back electromotive force lines of the motor, and reflects the result of the motor electromagnetic design.
2.Maximum thrust: The peak thrust of the motor, short-term, second level, depends on the safety limit capacity of the motor electromagnetic structure.
3.Maximum current: The maximum working current, corresponding to the maximum thrust, is lower than the demagnetization current of the motor.
4.Maximum continuous power consumption: Under the conditions of temperature rise and heat dissipation, the upper limit of the heat loss that the motor can continuously operate reflects the thermal design level of the motor.
5.Maximum voltage: The maximum power supply line voltage, mainly related to the insulation capacity of the motor.
6.Motor force constant: The thrust-to-current ratio of the motor, unit N/A or KN/A, reflects the result of the motor electromagnetic design, and in a sense, it can also reflect the electromagnetic design level.

7.Motor constant: The ratio of the motor thrust to the square root of power consumption, unit N/√W, is a comprehensive reflection of the motor electromagnetic design and thermal design level.
8.Back electromotive force : Motor back electromotive force (coefficient), unit Vs/m, reflects the result of the motor electromagnetic design, affecting the maximum operating speed of the motor under a certain supply voltage.
9.Motor attraction: For flat-type linear motors with iron core structure, especially permanent magnet motors, the normal attraction of the secondary permanent magnet to the primary iron core is one order of magnitude higher than the rated thrust of the motor, which directly determines the load-bearing capacity and selection of the support guide rails of the linear motion axis using the linear motor.

In summary, the selection of linear stepper motors is a process that takes into account multiple factors, including load specifications, stroke, speed, torque, speed, no-load starting frequency, phase selection, and motor selection under special environments.

Source:https://steppermotor1.livedoor.blog/archives/3241922.html