Definition and Function of Carbon Brush Motor

Motor carbon brush is the general name of motor carbon brush and generator carbon brush. The motor carbon brush looks a little like a pencil eraser strip. There are wires leading out from the top and the volume is large or small.

Definition of Carbon Brush Motor:

The function of motor is to change the current direction of DC motor and AC motor. DC motor is to change the conductive coil of the rotor, thereby changing the magnetic pole of the rotor, and then changing the motion of the motor. Carbon brush is used on commutator or sliding ring of motor as sliding contactor to derive current. It has good electrical conductivity, thermal conductivity and lubricity, and has certain mechanical strength and commutative spark instinct. Almost all brush motors use carbon brush, which is an important component of brush motors.

Motor carbon brushes are suitable for all kinds of motors, generators and axle machines. It has good commutation performance and long service life. The motor carbon brush is used on the commutator or sliding ring of the motor as a sliding contact to derive the current. It has good electrical conductivity, thermal conductivity and lubrication performance, and has certain mechanical strength and commutative spark instinct. Almost all motors use carbon brushes, which are important components of motors. Widely applicable to a variety of AC and DC generators, synchronous motors, battery DC motors, crane motor collector rings, all types of welding machines and so on. With the development of science and technology, the types and operating conditions of motors are becoming more and more diversified. Therefore, brushes of different grades are needed to meet these requirements. Therefore, the types of brushes are becoming more and more with the development of motor industry.

Carbon brush motor function:

1. External current (excitation current) is added to the rotating rotor (input current) through a carbon brush.

2. Introducing the static charge on the big axis through the carbon brush into the earth (ground carbon brush) (output current)

3. Change the direction of current (in rectifier motor, the brush also plays the role of commutation)

4. Lead the large axis (ground) to the protective device for the rotor grounding protection and the measurement of the positive and negative ground voltage of the rotor

Commutator consists of brush and commutation ring, carbon brush is a kind of brush. As the rotor rotates, the brush always rubs against the commutation ring, and spark erosion occurs at the moment of commutation, so the brush is a vulnerable part of DC motor. In order to improve the service life, operation stability and reduce the noise and electromagnetic interference of DC motor, brushless DC motor has gradually replaced brushless motor. In general, AC motors do not need constant magnetic field, so they do not need commutator and brush, but the volume of AC motors is generally larger. Electric motors used in household appliances are generally AC motors, such as fans, washing machines, refrigerators, air conditioners, etc. There are no carbon brushes, but there are also DC motors, such as many electric shavers, kitchen appliances, electric bicycles, etc. There are carbon brushes, that is, DC motors (excluding brushless ones). All motors using dry batteries are DC motors.

According to the object of motor carbon brush, it can be divided into: turbogenerator brush, steel rolling motor brush, traction motor brush, AC motor brush, aircraft motor brush.