The metal graphite grounding brush including silver is made in slide contact with a peripheral surface of an axle and grounds the axle. The mass ratio between silver and carbonaceous components including a volatile component in the brush is silver above 30% and up to 90% and carbonaceous components less than 70% and down to 10%. When the total of silver and carbonaceous components is made 100%, the volatile component is down to 2.0% and up to 15%. The brush grounds the axle reliably so that noise from a car radio is reduced and has a long service life and mechanical strength.

The metal graphite grounding brush including silver is made in slide contact with a peripheral surface of an axle and grounds the axle. The mass ratio between silver and carbonaceous components including a volatile component in the brush is silver above 30% and up to 90% and carbonaceous components less than 70% and down to 10%. When the total of silver and carbonaceous components is made 100%, the volatile component is down to 2.0% and up to 15%. The brush grounds the axle reliably so that noise from a car radio is reduced and has a long service life and mechanical strength.

A method of replacing a brush holder includes positioning a handle on the brush holder while the brush holder is connected to a support, rotating the handle relative to the brush holder in a first direction that is clockwise or counter-clockwise to connect the handle to the brush holder, removing the brush holder from the support by pulling the handle with the handle attached to the brush holder, rotating the handle relative to the brush holder in a second direction that is opposite to the first direction while pulling a trigger on the handle that moves a core in the handle upward in a cavity in the handle, and removing the handle from the brush holder.

A method of replacing a brush holder includes positioning a handle on the brush holder while the brush holder is connected to a support, rotating the handle relative to the brush holder in a first direction that is clockwise or counter-clockwise to connect the handle to the brush holder, removing the brush holder from the support by pulling the handle with the handle attached to the brush holder, rotating the handle relative to the brush holder in a second direction that is opposite to the first direction while pulling a trigger on the handle that moves a core in the handle upward in a cavity in the handle, and removing the handle from the brush holder.

A slipring with at least one slip ring module having at least one sliding track, and at least one wear indication track. A wear indication circuit is connected to the at least one wear indication track for monitoring electrical properties of the wear indication track and signaling an abnormal slipring condition. A wear indication track may be exposed to higher load, higher rotation speed, higher brush pressure force, or other lifetime-reducing influence as compared to a normal sliding track.

A slipring with at least one slip ring module having at least one sliding track, and at least one wear indication track. A wear indication circuit is connected to the at least one wear indication track for monitoring electrical properties of the wear indication track and signaling an abnormal slipring condition. A wear indication track may be exposed to higher load, higher rotation speed, higher brush pressure force, or other lifetime-reducing influence as compared to a normal sliding track.

The lifetime of sliding contact surface(s) of a precious metal or a precious metal alloy can be enhanced by embedding at least one nano-particle in the layer forming the sliding contact surface(s).

The lifetime of sliding contact surface(s) of a precious metal or a precious metal alloy can be enhanced by embedding at least one nano-particle in the layer forming the sliding contact surface(s).

A brush block assembly and a method of assembling the same are described. The brush block assembly includes two or more brushes arranged in one or more rows, each of the two or more brushes comprised of a pressed electrically conductive material with an integral lead wire and a terminal, and one or more terminal studs, each of the two or more brush blocks within a same one of the one or more rows being separated by one of the one or more terminal studs, a helical spring coupled respectively to each of the two or more brushes, and insulated wires from a power supply and the respective terminal of each of the two or more brushes within the same one of the one or more rows being retained by the one of the one or more terminal studs in the one of the one or more rows.

A brush block assembly and a method of assembling the same are described. The brush block assembly includes two or more brushes arranged in one or more rows, each of the two or more brushes comprised of a pressed electrically conductive material with an integral lead wire and a terminal, and one or more terminal studs, each of the two or more brush blocks within a same one of the one or more rows being separated by one of the one or more terminal studs, a helical spring coupled respectively to each of the two or more brushes, and insulated wires from a power supply and the respective terminal of each of the two or more brushes within the same one of the one or more rows being retained by the one of the one or more terminal studs in the one of the one or more rows.