What is the polishing method and function of the commutator

Update:14 May 2020

The commutator is a very important component in the motor equipment. When the motor is running, it will inevitably cause some damage to the commutator. In order to prevent the commutator from causing more serious damage, the commutation is required at this time. For polishing. So how should we polish the commutator? When polishing the commutator, it actually has its own unique method. In order to enable everyone to have more relevant understanding in this regard, the editor next to everyone What I will introduce is some related content about the polishing method of glider, I hope everyone can learn from it.
After a long-term operation of the DC motor, due to poor commutation, unreasonable brush arrangement and inappropriate brush material, streaks, regular burns, pitting and uneven wear on the surface of the commutator often form axial directions Wavy, usually need to use a special grinding stone to polish the commutator. When using it, you need to stick the grinding stone adhesive to the bottom of the grinding tool with the handle. When grinding, the speed of the commutator should be about 10m / s. Use both hands to firmly press the sandstone on the commutator. The pressure of the hand should not be too large, and it has been polished until the surface burn marks and channels can not be seen. After the grinding stone is polished, use a finer-grained emery cloth to surround the wooden block, and polish it again in the same way. For demanding commutators, use canvas instead of fine emery cloth and polish again.
Now the level of science and technology has been greatly improved, and various types of machinery and equipment are emerging one after another, which brings us convenience while also driving economic development. However, DC permanent magnet series excitation motors are used in many devices. The motor commutator is an important part that allows the DC permanent magnet series excitation motor to continue to rotate. Therefore, the use of the motor commutator is very important. Presumably everyone's understanding of the motor commutator is also limited. Now let's introduce the role of the motor commutator.
Structurally, the motor commutator is composed of several contact pieces in a circle, which are connected to each contact on the rotor. The two electrodes connected outside are called brushes, and only two of them are in contact. The principle of the motor commutator is that when the coil passes the current, it will be rotated by attraction and repulsion under the action of the magnet.When it is turned to balance with the magnet, the originally energized line is more corresponding to the motor commutator The contact piece is separated from the brush, and the brush is connected to the contact piece corresponding to the set of coils that generate the driving force. This repeats continuously, and the DC motor rotates. The motor commutator and the brush form a corresponding sliding friction pair in the motor. The effect of the motor commutator on the performance of the motor mainly depends on the relative speed (electric load, contact pressure, environmental conditions, etc.) when sliding relative to the brush at high speed Electrical contact behavior. In addition to transmitting longitudinal current, the motor commutator also has the task of current commutation in the short-circuit armature coil. These currents are the reverse current and reactance voltage generated when the main current motor commutator, causing the brush to cause side sparks and arcs when sliding on the surface of the motor commutator.

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