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.

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 motor includes an armature including a commutator, a bracket including a conductive brush and a first wall part, and a first deformable part. The conductive brush is in contact with the commutator. The first wall part includes a first surface extending along a first surface of the conductive brush. The first deformable part is in contact with both the first surface of the conductive brush and the first surface of the first wall part. The first deformable part is deformable in response to movement of the conductive brush.

A motor includes an armature including a commutator, a bracket including a conductive brush and a first wall part, and a first deformable part. The conductive brush is in contact with the commutator. The first wall part includes a first surface extending along a first surface of the conductive brush. The first deformable part is in contact with both the first surface of the conductive brush and the first surface of the first wall part. The first deformable part is deformable in response to movement of the conductive brush.

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.

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.

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.