The performance of electric power brush
The motor brushes (except for squirrel-cage motor outside) conduction current sliding contact body. In DC, it also bears on the armature winding induction alternating EMF commutation (rectifier) task. Practice has proved that: the reliability of the motor is running, largely depends on the performance of the brush.
In operation, the brush should meet the following requirements:
Commutator or collector rings surface can be generated by the cuprous oxide, copper oxide, i.e., carbon graphite particles such as moisture absorption of the oxide film.
Brushes on the commutator or collector ring wear is small, and their long service life.
Electrical and mechanical losses brush small loss.
Does not soften the brushless slip ring work, does not melt under the face does not appear on the motor hazardous sparks.
Brush work noise.
Brushes can meet these requirements, does not depend on the brush itself, but also depend on the factor structure of the motor, installation and adjustment of operating conditions, such as brush slip ring.