Electrical machine brush holder incorporating wear monitor

摘要

The brush holder (1) has a housing receiving a spring-loaded carbon brush, biased into contact with a current slip ring (6). The displacement path of the brush in the direction of the slip ring is detected for providing a signal indicating the need for replacing the brush when a given displacement is exceeded. Pref. the displacement is detected via an electrically insulated pressurised fluid line (24) coupled to an opening (23) in the brush holder housing which is released when the brush reaches a min. length.