A carbon brush unit for a direct current-excited brushed motor may include a carbon brush and a carbon brush holder which is formed to receive the carbon brush. An outer side of the carbon brush and/or an inner side of the carbon brush holder are formed such that in the assembled state of the carbon brush unit defined contact regions and air channels located therebetween result between the outer side of the carbon brush and the inner side of the carbon brush holder in order to dissipate heat, wherein the contact regions are less than 60% of the overall surface of the inner side of the carbon brush holder, wherein the outer side of the carbon brush has a nanostructuring which forms the defined contact regions and air channels.

The invention relates to a discharge device (10) for discharging electro-static charges from a shaft (39), comprising an annular holder (11) and a conductor arrangement (12), said conductor arrangement comprising at least one flexurally elastic conductor (13) arranged on the holder, said conductor being made of a carbon fiber arrangement, each end of the conductor being accommodated in the holder, said conductor arrangement comprising at least two conductor portions (33) extending transversely to a longitudinal shaft axis (32), said conductor portions each comprising a shaft contact portion (34) which together form a contact arrangement for being contacted with two circumferential contact areas of a shaft circumference (35), which are arranged in a shaft contact plane W, in such a manner that the shaft contact portions are arranged tangentially to the shaft circumference upon contact to the shaft circumference.

The invention relates to a discharge device (10) for discharging electro-static charges from a shaft (39), comprising an annular holder (11) and a conductor arrangement (12), said conductor arrangement comprising at least one flexurally elastic conductor (13) arranged on the holder, said conductor being made of a carbon fiber arrangement, each end of the conductor being accommodated in the holder, said conductor arrangement comprising at least two conductor portions (33) extending transversely to a longitudinal shaft axis (32), said conductor portions each comprising a shaft contact portion (34) which together form a contact arrangement for being contacted with two circumferential contact areas of a shaft circumference (35), which are arranged in a shaft contact plane W, in such a manner that the shaft contact portions are arranged tangentially to the shaft circumference upon contact to the shaft circumference.

A shaft earthing arrangement including a housing which receives a shaft and a fluid. The shaft is associated with an earthing ring configured to produce an electrically conductive contact between the shaft and housing. The earthing ring has a disk-shaped contact member supported in a lip-like manner on a covering of the shaft. A first contact face is formed from the contact member and a second contact face is formed from the shaft. At least one of the first contact face and the second contact face is provided with a surface structuring.