Power tools carbon brush-brush type selection use 1. in order to ensure the normal operation of the motor, accurate selection of brush type is very important, because the manufacturing of carbon brush when the selection of raw materials and technology is not the same, its technical function is also different. Therefore, in the choice of carbon brush, we should think about the function of carbon brush and the motor's demand for carbon brush. The carbon brush must be installed in the brush holder to ensure that it can move up and down leisurely. The vacancy between the carbon brush and the inner wall of the brush holder is between 0.1-0.3mm, so as to prevent the carbon brush and the brush holder from shaking due to excessive vacancy. The distance between the margin under the carbon brush and the outer surface of the commutator should be kept at about 2mm. If the distance is too small, the brush holder will touch the commutator briefly. If the distance is too large, the carbon brush will easily shiver and cause damage.

2 The mark of excellent use of carbon brushes for electric tools shall be:

A in the commutator or collector ring surface can quickly form a layer of uniform, moderate and stable oxidation film.

B carbon brush has a long service life and does not wear the commutator or collector ring

C carbon brush has excellent commutation and collection function, the spark restraint in the allowable range, and the energy loss is small.

D when the carbon brush is working, it is not hot, the noise is small, the equipment is reliable and not damaged.

3. The carbon brush of the electric tool should be replaced with a new carbon brush when it is worn to a certain extent. It is best to replace the carbon brush at one time. Assuming that the old and the new are mixed, the current distribution may be uneven. For large units, stopping and replacing carbon brushes will definitely affect the production, and we can choose not to stop. We usually recommend that customers replace 20% of the carbon brushes (I .e. 20% of each brush rod of each motor) at a distance of 1-2 weeks at a time, and gradually replace other carbon brushes after running-in to ensure the normal and continuous operation of the unit.

4. On the same electric motor, the same type of carbon brush should be used in principle. However, for large and medium-sized motors with extremely difficult commutation, twin carbon brushes can be selected. The lubricating function is good when sliding in, and carbon glutathione with strong spark suppression ability is selected when sliding out to replace the returned motor or the motor working under vibration conditions. The unit pressure should be properly moved to ensure normal operation. For example, the unit pressure of the electric tool carbon brush of the tractor motor is 0.4-0.6kgf/cm2.

6. In order to make the carbon brush of the electric tool have excellent contact with the commutator, the new carbon brush should be ground radian, which is usually embedded in the commutator groove in the motor amount 2, which will scratch the carbon brush and the appearance of the commutator when the motor is working. After grinding arc, the motor first 20-30% to load work for several hours, so that the carbon brush and commutator running, and establish a uniform oxide film. Then gradually run the current to the extra load.

Usually the unit pressure of carbon brushes for electric tools is too low, and everyone has tens of millions of sparks.