1. The influence of the pressure of the compression spring. If the pressure of the compression spring is too great, the mechanical wear of the carbon brush will increase; at the same time, if the pressure of the compression spring is too low, although the friction between the carbon brush and the slip ring is small, poor contact will easily produce sparks, which is also undesirable.
2. Influence of current. Generally speaking, for graphite carbon brushes, the current flowing through the positive carbon brush is larger than the current flowing through the negative carbon brush, so the wear of the positive carbon brush is longer . It wears more than the negative carbon brush. And the positive slip ring wears more than the negative slip ring, so every time the unit is overhauled, the positive and negative polarity wire heads of the carbon brush need to be adjusted.
3. The smoothness of the slip ring surface. The smoother the surface of the slip ring, the lower its coefficient of friction and the lower the wear rate of the carbon brush. In addition, there is an oxide film on the surface of the slip ring, which is also very beneficial in reducing the friction coefficient and reducing the wear of the carbon brush.
4. The influence of the carbon brush material. Carbon brushes of different manufacturers and models have different compositions and structures, and their wear rates are also different. Choosing the same type of carbon brush can reduce the uneven wear rate of the carbon brush itself.