Brush assembly for dynamoelectric machine

摘要

A brush assembly preferably for a universal motor comprises a tubular brush holder 13, a carbon brush 33, an arm 31 for biasing the brush and a spring 85 for biasing the arm. The brush is slidably mounted in the cavity 21 of the holder. A stop 61 is formed between the brush and the holder and has a disengaged position to permit travel of the brush partially through the inner end 25 of the holder and an engaged position to limit travel of the brush through the inner end 25 of the holder. The electrically conductive arm 31 is pivotally mounted on the support and extends through a slot 29 of the holder. A distal end 60 of the brush engages the outer end 53 of the brush and biases the brush 33 toward the inner end 25 of the cavity. The spring 85 is connected between the support 15 and the arm 31 for biasing the arm 31 into engagement with the brush 33. The arm is spaced outwardly of the end of the slot to apply a bias to the brush when the stop is in an engaged position. As a result the brush, when worn out is firmly held between the arm and the stop to reduce degradation of the arm 33 and commutator 35. <IMAGE>