DC motor is divided into brushless DC electric motor and brushed DC electric motor. Brushless DC motor which swap stator and rotor of DC motor. The rotor generates air gap flux for a permanent magnet and the stator is composed of multiple phase windings as armature. And it is similar to permanent magnet synchronous motor in the structure. Brushed DC motor’s two brushes (copper brush or carbon brush) apply the negative and positive plate of the power directly to the rotor’s commutation device through the insulating seat to be fixed on the back cover of the motor. And then the commutation device is connected to the rotor coil so that the three coil polarity continuously alternating transform with the two magnets fixed on the shell acting to form force and turn up. Because of the commutator and the rotor are fixed together and the brush and the shell (stator) are fixed together, the brush and commutator continues to produce a lot of resistance and heat generated by the friction between them when the motor rotates. So there is large loss of the brushed DC motor with a low efficiency. But it also has the advantages of simple manufacture and low cost.