For sewing machine industrial applications, we usually use servo motor and stepping motor, here we talk about the difference between these two motors:
1. Stepper motor is controlled by DC pulse. Generally speaking, its power is relatively small. It is used in the open-loop automatic control system with low precision requirements. One disadvantage of stepper motor is that it is easy to lose step!
The difference between stepper motor and ordinary motor is that stepper motor is controlled by pulse signal. Stepping motor relies on a kind of electronic switch device called ring distributor, through the power amplifier to make the excitation winding turn on DC power in turn. Because the excitation windings are arranged according to a certain rule in the space, after connecting with the DC power supply in turn, a step-by-step rotating magnetic field will be formed in the space, which makes the rotor rotate step by step. With the increase of pulse frequency, the speed will increase. The rotation of stepping motor is related to the number of phases, the number of distribution and the number of rotor gears.
Now more commonly used stepper motor includes reactive stepper motor, permanent magnet stepper motor, hybrid stepper motor and single-phase stepper motor. The rotor magnet of the reactive stepper motor is made of soft magnetic material, and the stator has multi-phase excitation winding, which uses the change of magnetic permeability to generate torque. At this stage, the reactive stepper motor gets the most applications.
The main difference between stepper motor and ordinary motor lies in the form of pulse drive. It is this feature that stepper motor can be combined with modern digital control technology. However, the stepping motor is not as good as the traditional closed-loop control DC servo motor in the control accuracy, speed range and low-speed performance. Stepper motor can be used when the precision is not particularly high. Stepper motor can play its advantages of simple structure, high reliability and low cost. When used properly, it can even compare with the performance of DC servo motor.
Stepping motor is widely used in various fields of production practice. Its biggest application is in the manufacturing of CNC machine tools, because the stepper motor does not need a / D conversion, can directly convert the digital pulse signal into angular displacement, so it is considered to be the ideal actuator of CNC machine tools. Early stepping motor output torque is relatively small, can not meet the needs, in use and hydraulic torque amplifier together to form a hydraulic pulse motor. With the development of stepping motor technology, stepping motor has been able to be used alone in the system, and has become an irreplaceable executive component. For example, the stepper motor is used as the drive motor of CNC milling machine feed servo mechanism. In this application, the stepper motor can complete two tasks at the same time, one is to transfer torque, the other is to transfer information. The stepping motor can also be used as the driving motor of synchronous system of CNC worm wheel edging machine. In addition to the application in CNC machine tools, stepper motor can also be used in other machines, such as the motor in the automatic feeder, the motor as a general floppy disk driver, and can also be used in printers and plotters.
With its remarkable characteristics, stepping motor plays an important role in the era of digital manufacturing. With the development of different digital technology and the improvement of stepping motor technology, stepping motor will be applied in more fields.
There are many differences. Servo is mostly used in closed-loop system, while stepper is mostly used in open-loop system. Servo motor can run at high speed, but stepper is not as high speed as servo: stepper motor is generally less than 1500 rpm, servo can reach more than 3000 rpm; There is, stepper motor can not start at high speed, the accuracy is not the same. Step angle limit, that is, the accuracy is not as good as servo.
2. Servo motors are divided into AC and DC, with relatively high power and high precision; The main difference between the two is to see whether there is a photoelectric encoder at the end of the motor! Servo motors rely on photoelectric encoders to feed back position signals. By the way, closed-loop control can be divided into semi closed-loop and full closed-loop. However, semi closed-loop devices are commonly used. Only very precise equipment can use full closed-loop devices. For example, the last one mentioned by 8 building is full closed-loop devices.
