A high current and RPM-capable slip ring assembly for use in a selected application for transferring electricity between an exterior environment and an interior environment that includes a non-rotating electrical power member with concentric electrically conducting power transmission bands with wiring and a rotating electrical power member with concentric electrically conducting power transmission bands with wiring and a housing that surrounds both the non-rotating electrical power member and rotating electrical power member to align the first set of concentric electrically conducting power transmission bands and the second set of concentric electrically conducting power transmission bands to slide on one another during rotationally operation of the slip ring assembly.

A high current and RPM-capable slip ring assembly for use in a selected application for transferring electricity between an exterior environment and an interior environment that includes a non-rotating electrical power member with concentric electrically conducting power transmission bands with wiring and a rotating electrical power member with concentric electrically conducting power transmission bands with wiring and a housing that surrounds both the non-rotating electrical power member and rotating electrical power member to align the first set of concentric electrically conducting power transmission bands and the second set of concentric electrically conducting power transmission bands to slide on one another during rotationally operation of the slip ring assembly.

A method for making contact wires for sliprings comprising the steps of: coating and/or plating a wire with a first metal of the group of nickel, chrome or a combination thereof; coating and/or plating the wire with a second metal of the group of gold, silver, or a combination thereof; delivering laser radiation and generating an interference pattern of the laser radiation to the surface of the wire; heating the surface selectively as defined by the interference pattern, modifying of the crystal structure and/or providing protrusions and/or recesses due to melting and/or evaporation of the surface material.

A starter includes a motor configured with a direct current motor. The direct current motor has a brush and a commutator. The brush is a sintered material formed of graphite and a copper powder. The commutator is formed of either copper or a copper alloy that has a copper content of 99% or more. A surface of is a sliding portion of the commutator which has sliding movement with the brush is provided with a graphite cover-layer that contains graphite as a main component. The graphite cover-layer contains a hard compound which has a Vickers hardness higher than 10 GPa and a metal sulfide solid lubricant.

A starter includes a motor configured with a direct current motor. The direct current motor has a brush and a commutator. The brush is a sintered material formed of graphite and a copper powder. The commutator is formed of either copper or a copper alloy that has a copper content of 99% or more. A surface of is a sliding portion of the commutator which has sliding movement with the brush is provided with a graphite cover-layer that contains graphite as a main component. The graphite cover-layer contains a hard compound which has a Vickers hardness higher than 10 GPa and a metal sulfide solid lubricant.

Systems and methods to mitigate electrical voltage on a rotating shaft in an oil rich environment exposed to a viscous fluid or immersed in oil are disclosed. An example grounding brush assembly includes a plurality of conductive filaments configured to extend through the viscous medium surrounding the rotating shaft to be in electrical contact with the rotating shaft when the brush assembly is disposed proximate the shaft.

Systems and methods to mitigate electrical voltage on a rotating shaft in an oil rich environment exposed to a viscous fluid or immersed in oil are disclosed. An example grounding brush assembly includes a plurality of conductive filaments configured to extend through the viscous medium surrounding the rotating shaft to be in electrical contact with the rotating shaft when the brush assembly is disposed proximate the shaft.

A laminated carbon brush for a liquid pump motor slides in a liquid fuel on a disk-like commutator. The laminated carbon brush includes two layers of a lower resistivity layer and a higher resistivity layer. In both the lower resistivity layer and the higher resistivity layer, circular directional resistivities of the brush along a circular direction in the rotation of the commutator are higher than non-circular directional resistivities of the brush along a radial direction of the commutator and a perpendicular direction to the sliding surface of the commutator. A non-circular directional resistivity of the higher resistivity layer are higher than or equal to 90,000 .Math.cm. No spark discharges occur if the fuel pump motor is operated to output a high power.

A laminated carbon brush for a liquid pump motor slides in a liquid fuel on a disk-like commutator. The laminated carbon brush includes two layers of a lower resistivity layer and a higher resistivity layer. In both the lower resistivity layer and the higher resistivity layer, circular directional resistivities of the brush along a circular direction in the rotation of the commutator are higher than non-circular directional resistivities of the brush along a radial direction of the commutator and a perpendicular direction to the sliding surface of the commutator. A non-circular directional resistivity of the higher resistivity layer are higher than or equal to 90,000 .Math.cm. No spark discharges occur if the fuel pump motor is operated to output a high power.

A carbonaceous material is fabricated by a mixture of carbon powder and a binder. 10% by weight or more and 60% by weight or less of metal powder to the fabricated carbonaceous material is mixed. The mixed carbonaceous material and metal powder are pressurized and formed. A brush base material is fabricated by burning of the pressurized and formed carbonaceous material and metal powder. The fabricated brush base material is impregnated with oil. An impregnation rate of the oil to the mixed carbonaceous material and metal powder may be 0.5% by weight or more, for example.