Carbon brushes and generator slip rings do not refer to the same thing.
As a sliding contact, carbon brushes are widely used in many electrical equipment. The product materials mainly include electrochemical graphite, grease-impregnated graphite and metal graphite (containing copper and silver).
Slip rings are electrical components responsible for connecting and transmitting energy and signals to rotating bodies. According to the transmission medium, slip rings are divided into electrical slip rings, fluid slip rings and smooth slip rings, which can also be collectively called "rotary connections" or "rotary connections".
The slip ring is usually installed in the rotation center of the equipment and is mainly composed of two parts: rotating and fixed. The parrotating part is connected to the rotating structure of the device and rotates with it, called "rotor", and the fixed part is connected to the energy source of the fixed structure of the device, called "stator".
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2. From the use point of view, the main signs of good performance of the brush are as follows:
(1) Long service life and no wear of the commutator or ring current collector.
(2) It has good switching and current collection performance, suppressing sparking within the allowable range and reducing lossesof energy.
(3) When the brush is running, it will not overheat, make much noise, or be damaged.
(4) During operation, a uniform, moderate and stable oxide film can quickly form on the surface of the collector or collector ring.
3. Test brushes using instruments. From a technical point of view, electric brushes must comply with national ministerial standards. The instrument can be used to test the performance of the brush according to the requirements of “Brush Technical Performance Table”. Such as brush resistivity, Rockwell hardness, volume density, current density, contact voltage drop, coefficient of friction, 50 hours of wear, allowable peripheral speed, unit pressure and even content metal, etc.
Baidu Encyclopedia-Carbon Brush
1. The influence of the pressure of the compression spring. Ifthe pressure of the compression spring is too large, 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. More the ssurface of the slip ring is smooth, the lower its friction coefficient, the lower the wear rate of the carbon brush. In addition, the slip ring tableThere is an oxide film on the surface, which is also very beneficial to reduce the friction coefficient and reduce 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.