2. Stepper motor
The so-called stepper motor is an actuator that converts electrical pulses into angular displacement; more generally, when the stepper driver receives a pulse signal, it drives the stepper motor to rotate a fixed angle in the set direction. We can control the angular displacement of the motor by controlling the number of pulses to achieve precise positioning. At the same time, the speed and acceleration of the motor can be controlled by controlling the pulse frequency to achieve the purpose of speed regulation. At present, the more commonly used stepping motors include reactive stepping motors (VR), permanent magnet stepping motors (PM), hybrid stepping motors (HB), and single-phase stepping motors.
The difference between a stepper motor and a normal motor is mainly in the form of its pulse drive. It is this feature that the stepper motor can be combined with modern digital control technology. However, the stepping motor is not as good as the traditional closed-loop controlled DC servo motor in terms of control accuracy, speed variation range and low-speed performance; therefore, it is mainly used in applications where the accuracy requirements are not particularly high. Stepper motors are widely used in various fields of production practice because of their simple structure, high reliability and low cost. Especially in the field of CNC machine tools, because stepper motors do not require A/D conversion, The digital pulse signal is directly converted into an angular displacement, so it has been considered as the most ideal CNC machine tool actuator.
In addition to its application on CNC machines, stepper motors can also be used on other machines, such as motors in automatic feeders, as general-purpose floppy disk drives, as well as in printers and plotters.
In addition, stepper motors also have many drawbacks; stepper motors can run normally at low speeds due to the no-load start-up frequency of stepper motors, but they cannot start at higher speeds than with a certain speed, accompanied by sharp howling sounds; The accuracy of the subdivision driver of the manufacturer may vary greatly. The larger the subdivision number, the more difficult it is to control the accuracy; and the stepper motor has large vibration and noise when rotating at low speed.
