US Patent 7671507 Brush bag for a dynamo-electric machine

A brush bag, a brush and a current transfer unit for a dynamo-electric machine comprising a commutator, in particular for an electromotor. The current transfer unit comprises at least the brush, which is embodied, in particular, as a multi-layer carbon brush, and a brush bag. The brush bag is configured in such a manner that the distance between the brush and the brush bag in a front guiding area is smaller than the distance in a rear guiding area. Beating of the brush on the brush bag is visibly reduced due to the configuration thereof and noise caused by the beat is avoided.