The original name of the commutator

Update:29 Mar 2021

English: commutator, commonly known as commutator.
It is a component of the DC permanent magnet series motor in order to keep the motor rotating.
The commutator includes: mechanical commutator, semi-plastic commutator, full-plastic commutator, motor commutator, hook commutator, slot commutator, planar commutator, DC motor commutator , Micro-motor commutator and other commutator companies The commutator used on the automobile starter mainly uses a mechanical arch commutator and a plastic commutator.

03-04.JPG In terms of structure, the commutator is a circle with several contact pieces, which are connected to each contact on the rotor. The two electrodes connected on the outside are called brushes to contact it, and only touch one of them at the same time. Two.

The principle is that when the coil passes current, it will be rotated by the force of attraction and repulsion under the action of the permanent magnet. When it turns to balance with the magnet, the original energized wire will be compared with the contact piece on the corresponding commutator. The brushes are separated, and the brushes are connected to the contact pieces corresponding to the set of coils that generate the driving force, so that the DC motor will rotate after repeating.

If there is no function of the commutator, the motor can only be stuck in less than half a turn and can only be used as an electric brake. The centrifugal force generated when the motor rotates is used as the power to control the size of the starting resistance, so as to reduce the starting current of the motor and increase the starting torque, so that the winding asynchronous electric idea can realize the brushless automatic control operation. It is mainly composed of casing, starting fluid, moving plate, spring, terminal, safety valve, exhaust valve and so on. The hydraulic resistance starter has the characteristics of small starting current, large starting torque, automatic adaptation to changes in power and load, protection of the motor, etc. The commutator is a high-speed rotating device, and its rotor winding will be affected by electromotive force and centrifugal force. It has been running under the rated parameters so far, but the welding port of the rotor winding and the commutator rising piece is the weak link of the commutator rotor, and the traditional soldering process is used, combined with the measurement result of the DC resistance between the pieces, to judge the rotor The welding point between the winding and the commutator riser is loose, causing the end wire to fatigue, increasing the contact resistance, increasing the heat generation, and accelerating the oxidation of the contact surface, so that the contact resistance is further increased, and the heat generation is further increased. Such a vicious circle eventually causes the commutator rotor insulation to burn at high temperatures, arc discharge to the ground, and damage the commutator. The results of the disassembly inspection of the commutator show that the relevant data and judgment conclusions of the rotor winding test are correct. In addition to transmitting the longitudinal current when the motor commutator is working, there is also a current commutation task performed in the short-circuit armature coil.

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