Specification and application of commutator

Update:28 Dec 2020

Commutators mainly have hook type, groove type, flat type and other specifications. It is refined from imported raw materials, and the function of the product reaches the predecessor level. It is widely used in electric tools, household appliances, automobiles, motorcycle motors and other fields; , Carbon brush holders, wiring boards have various specifications and models, which are used in automobile generators, gasoline generators and other fields. The commutator is a rectifier, and its function is to make the direction of the current in the armature winding alternate. In order to ensure that the direction of the electromagnetic torque is always the same. In a generator, the commutator can make the alternating electric potential in the component become the DC electric potential between the brushes; in the electrical idea, it can make the external DC current become the alternating current in the component Electric current produces torque in a constant direction. Information about commutators and slip ring motors.

The commutator is composed of a brush and a commutation ring, and a carbon brush is a kind of brush. Due to the rotation of the rotor, the brush always rubs against the commutation ring, and spark erosion occurs at the moment of commutation, so the brush is a vulnerable part in the DC motor.

In order to improve the service life and operational stability of DC motors and reduce the noise and electromagnetic interference of DC motors, brushless DC motors are gradually replacing brushed motors.

There are two types of AC asynchronous motors: the general factory uses a relatively large starting load and uses a slip ring on the wound asynchronous motor, so it uses electric (carbon) brushes (such as lifting, steel rolling motors, etc.), while the light load starting uses a squirrel cage Type induction motors do not have slip rings, so they do not need electric (carbon) brushes (such as electric fans, washing machines, air conditioners, refrigerators, etc.). DC motors have commutators, so electric (carbon) brushes are used. Hand drills are generally DC motors. The bench drill is an AC asynchronous induction motor; although general toys and electric shavers are DC motors, because of their simple structure, in order to reduce costs, they use phosphorus-containing elastic brass sheets to replace electric (carbon) brushes. The direction device is a vulnerable part of the electric shaver (the wire package in the motor is generally not broken).

Generally, AC motors do not need a constant magnetic field, so there is no need for a commutator, so there is no need for brushes; however, the volume of AC motors is generally relatively large. The motors used in household appliances are generally AC motors, such as electric fans, washing machines, refrigerators, air conditioners, etc. There are no carbon brushes, but there are also DC motors. For example, many electric shavers, small kitchen appliances, electric bicycles, etc. have carbon brushes, that is, DC motors (excluding brushless ones). Motors that use dry batteries are all It is a DC motor commutator.

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