A motor is a device that converts 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, various control motors need to be adopted as the components of the automation system. In the automatic control system of artificial satellite, the motor is also indispensable. In addition in national defense, culture and education, medical treatment and daily life (in the modern household appliance industry) electric motor also more and more widely used.

　　Structure and function of each part

　　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, housing, junction box, and so on.

　　The stator is used to generate magnetic fields and to provide mechanical support for the motor. The stator of the motor consists of three parts: stator core, stator winding and frame. The stator windings are embedded in the stator core, and the induction electromotive force is generated when current is applied to realize electrical energy conversion. The main function of the stand is to fix and support the stator core. When the motor is running, the heat due to internal loss is transmitted to the motor through the iron core, and then distributed to the surrounding air by the surface of the motor. In order to increase the heat dissipation area, the motor is usually designed as heat dissipation sheet on the outside surface of the seat.

　　The rotor of motor is composed of rotor core, rotor winding and rotor shaft. The rotor core is also used as part of the motor's magnetic circuit. The rotor winding ACTS as an induction electromotive force and generates electromagnetic torque through current. The rotating shaft is the main part to support the weight of the rotor, transfer the torque and output the mechanical power.