These currents are the reverse current and reactance voltage generated during the main current motor commutator, causing the brushes to slide on the surface of the motor commutator, which will cause edge sparks and arcs. The influence of the motor commutator on the motor performance depends on Under certain premises, it is the process of realizing circuit conduction when it slides with the brush at a relatively high speed. Although the description of this process is more complicated and theoretical research is still under development, through the comparative analysis of the operating conditions of micromotors at home and abroad, it can be It is determined that wear is the most pivotal factor leading to changes in contact resistance. Commutators mainly have hook, groove, and plane specifications. They are refined from imported raw materials. The product's performance has reached the international level of improved predecessors. It is widely used in power tools, Household appliances, automobiles, motorcycle motors and other fields; collector rings, carbon brush holders, wiring boards have various specifications and models, which are used in automobile generators, gasoline generators and other fields. The commutator plays a role of rectification. The direction of the current in the armature winding is alternating to ensure that the direction of the electromagnetic torque is always the same. In the generator, the commutator can make the alternating potential in the element into the DC potential between the brushes; In the idea, it can change the external DC current into the AC current in the component, and generate a constant direction torque. Information about the commutator and slip ring motor: the commutator is composed of brushes and commutating rings, and the carbon brushes are the brushes. Kind of. 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: Generally, the winding asynchronous motor used in factories has a relatively large starting load and uses electric (carbon) brushes (such as lifting, steel rolling motors, etc.) because of the slip ring, 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 the simple structure, in order to reduce the cost, they use phosphorus-containing elastic brass plates to replace the electric (carbon) brush. 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 (not including brushless). Motors that use dry batteries are all It is a DC motor.