Dc motor

A direct current motor is a motor driven by direct current, which achieves motion by rotating the rotor in a magnetic field and generating a rotating cutting magnetic inductance line with an adjacent magnetic pole. All motors are composed of stator and rotor, in the DC motor, in order to make the rotor turn up, you need to constantly change the direction of the current, otherwise the rotor can only turn half a turn, so the DC motor needs a commutator. The generalized DC motor includes brush motor and brushless motor.

Brush machine

Brush motor, also known as DC motor or carbon brush motor, often said DC motor refers to the brush DC motor, which uses mechanical commutation, the external magnetic pole does not move the internal coil (armature), the commutator and the rotor coil rotate together, the brush and the magnet do not move, so the commutator and the brush friction friction, to complete the current direction switch.

advantage

1, starting and speed control performance is good, speed control range is wide and smooth, overload ability is strong, little affected by electromagnetic interference,

2, DC motor has good starting characteristics and speed regulation characteristics;

3, DC motor torque is relatively large

shortcoming

1, DC motor manufacturing is more expensive;

2, compared with asynchronous motor, DC motor structure is complex, the use of maintenance is not convenient, and to use DC power:

3, the complex structure limits the further reduction of the volume and weight of the DC motor, especially the sliding contact of the brush and the commutator causes mechanical wear and sparks, so that the DC motor has more failures, low reliability, short life, and large maintenance workload.

4, the commutator spark caused both the electrical corrosion of the commutator, or a radio interference source, will have a harmful effect on the surrounding electrical equipment. The larger the capacity of the motor, the higher the speed, the more serious the problem. Therefore, the brush and commutator of ordinary DC motors limit the development of DC motors to high speed and large capacity.