The DC motor of the car starter is the power output part of the starter. Its structure is mainly composed of armature rotor, magnetic pole stator, commutator, brush and other components.

1. The armature rotor, the armature rotor is the rotating part of the DC motor. It is an iron core formed by superimposing round silicon steel sheets with grooves. The grooves are wound with winding wires. Due to the large starting torque of the engine, the current is very large. 200 to 600 amps, the wire diameter is thicker.

2. The magnetic pole stator is composed of an iron core fixed on the casing and a magnetic pole winding, generally composed of two pairs of magnetic poles, and the casing together forms a magnetic circuit.

3. Commutator. The function of the commutator is to introduce current into the rotating stator. It is composed of many dovetail copper sheets sandwiched with mica sheets. The armature winding is welded at the dovetail.

4. The brush and the brush holder, the positive brush holder is insulated and connected to the end cover, the negative brush holder and the end cover are directly grounded, the brush is pressed with copper powder and carbon powder, and transmits electric energy to the commutator .