How to maintain carbon brushes



NIDE carbon brush

Carbon brush maintenance

The carbon brush should be maintained in time during operation. Poor maintenance can easily lead to failures, and even stop production. If we can strengthen the maintenance of the collector parts, find problems early and solve problems, we can avoid many failures.


Motors with commutators, because the carbon brush not only acts as a conducting current, but also acts as a commutation, so the monitoring workload is greater. It is very important to constantly observe the state and characteristics of the reversing spark. The size and state of the DC motor reversing spark is a reflection of the combined effects of many factors affecting commutation, and is the main indicator of the good or bad motor operation.

Therefore, careful observation of the spark generation and its changing law is the analysis of the cause of spark generation and the basis for taking measures to eliminate sparks.


Carbon brush running spark state

The spark shape produced by the carbon brush during motor operation is usually divided into point sparks (very weak and discontinuous); granular sparks (larger than point sparks, brightness is stronger than point sparks); fireball sparks (in carbon brushes) Draw a red or white bright spherical spark that stays on the side or floats; Splash-like sparks (the fire tongue drags out a long distance, there is a phenomenon of Mars flying); Ring-shaped sparks (the carbon brush slides out and the spark is long and attached) Forming a ring-shaped fire on the surface of the commutator, forming an arc short between the positive and negative brush holders in severe cases)


Performance requirements for motor carbon brush holders

The motor carbon brush holder is mainly used to keep the carbon brush stable, it is convenient to check and replace the carbon brush regularly, and it is easy to load and unload the carbon brush in the brush box, and the exposed part of the carbon brush under the brush box can be adjusted (the lower end edge of the brush box and the commutator or set) The gap on the surface of the electric ring) to prevent the commutator or the collector ring from being worn out, and to reduce the influence of the change of the carbon brush pressure, the pressing direction and the pressing position on the wear of the carbon brush.

Carbon brush holders mainly use bronze castings, aluminum castings and other synthetic materials. The material of the brush holder itself needs to have good mechanical strength, processing performance, corrosion resistance, heat dissipation performance and electrical conductivity. Moreover, the carbon brush holder structure needs to be very strong.