1. insulation material: materials that can prevent the passage of electric current, the volume resistivity is usually greater than 109.Cm

2. Function of insulating material: Isolate the charged part from the non-charged part or the part with different potential, so that the current can flow along a certain path.

3. motor: electromagnetic mechanical equipment for energy conversion.

4. motor classification: transformers, DC motors, AC motors, control motors, and pulse motors.

5, the basic structure of motor: stationary part (stator): produce magnetic field, constitute magnetic circuit, mechanical support. Clearance (air gap): an important part of the magnetic circuit to ensure the safe operation of the motor, rotating part (rotor): induction potential, electromagnetic torque, to achieve energy conversion.

Stator structure: frame, main pole, Huan Xiangji, end cap and brush device.

The structure of the rotor is rotating shaft, armature core, armature winding and commutator.

5. Armature winding: It is composed of a certain number of armature coils connected according to certain laws; it is the circuit part of DC motor, and also the part of induction electromotive force, which produces electromagnetic torque for electromechanical energy conversion.