An electric motor is a device for converting electrical energy into mechanical energy. Electric motors are widely used in machinery, metallurgy, petroleum, coal, chemistry, aviation, transportation, agriculture and other industries. With the continuous improvement of industrial automation, it is necessary to use a variety of control motors as components of the automation system. In addition, electric motors are increasingly widely used in national defense, culture, education, medical treatment and daily life (in the modern home appliance industry).

　　Structure and function of parts

　　Generally, the motor is mainly composed of two parts: the fixed part is called the stator, and the rotating part is called the rotor. In addition, there are end cover, fan, housing, stand, junction box and so on.

　　The stator is used to generate a magnetic field and provide mechanical support for the motor. The stator of the motor is composed of stator core, stator winding and frame. The stator windings are embedded in the stator core, and the induction electromotive force is generated when the current is passed to realize the electrical energy conversion. The main function of the machine base is to fix and support the stator core. When the motor is running, the heat generated by internal loss is transmitted to the frame through the core, and then sent out to the surrounding air from the surface of the frame. In order to increase the heat dissipation area, the general motor is designed as a heat dissipation chip on the outer surface of the frame.

　　The rotor of the motor consists of the rotor core, rotor winding and shaft. The rotor core is also part of the motor's magnetic circuit. The effect of rotor winding is induction electromotive force, through the current and electromagnetic torque. The shaft is the main component that supports the weight of the rotor, transfers the torque and outputs the mechanical power.