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.

An electrical device including an electrode arrangement having a magnet, and an electrode, an electrically conducting movable device, movable relative to the electrode arrangement and spaced apart from the electrode arrangement, whereby a gap (G) is formed therebetween, and a suspension including a liquid, a plurality of magnetic particles dispersed in the liquid and a plurality of non-magnetic electrically conducting particles dispersed in the liquid, which non-magnetic electrically conducting particles have higher electric conductivity than the magnetic particles, wherein the suspension) extends between the electrically movable device and the electrode arrangement in the gap (G), and wherein the magnet is arranged to provide a magnetic field through the suspension to thereby align the non-magnetic electrically conducting particles between the electrode arrangement and the electrically conducting movable device to obtain an electrical connection between the electrode arrangement and the electrically conducting movable device.

An electrical device including an electrode arrangement having a magnet, and an electrode, an electrically conducting movable device, movable relative to the electrode arrangement and spaced apart from the electrode arrangement, whereby a gap (G) is formed therebetween, and a suspension including a liquid, a plurality of magnetic particles dispersed in the liquid and a plurality of non-magnetic electrically conducting particles dispersed in the liquid, which non-magnetic electrically conducting particles have higher electric conductivity than the magnetic particles, wherein the suspension) extends between the electrically movable device and the electrode arrangement in the gap (G), and wherein the magnet is arranged to provide a magnetic field through the suspension to thereby align the non-magnetic electrically conducting particles between the electrode arrangement and the electrically conducting movable device to obtain an electrical connection between the electrode arrangement and the electrically conducting movable device.

An oil lubricated compressor having a universal motor, efficient starting and re-starting characteristics, and a long operating life. The oil lubricated compressor can have a brushed or brushless universal motor which can drive a cooling fan and a pump. The universal motor can achieve a high torque to voltage ratio, as well as a high torque to current ratio, upon starting or re-starting of the compressor. Optionally, the oil lubricated compressor can use a single cooling fan disposed in the compressor at a location which is between the universal motor and a cylinder head of the pump.

A slide-contact portion of a motor has a slide-contact face that contacts a rotating rotor. The slide-contact portion is composed of a material containing an intermetallic compound phase produced by chemical reaction between a first metal which is Sn or an alloy including Sn and a second metal which is a CuNi alloy, a CuMn alloy, an AgPd alloy, a CuAl alloy, or a CuCr alloy.

A slide-contact portion of a motor has a slide-contact face that contacts a rotating rotor. The slide-contact portion is composed of a material containing an intermetallic compound phase produced by chemical reaction between a first metal which is Sn or an alloy including Sn and a second metal which is a CuNi alloy, a CuMn alloy, an AgPd alloy, a CuAl alloy, or a CuCr alloy.

The invention relates to a ring electrode for a slip ring for transmitting electrical energy between machine parts, of which at least one machine part can be rotated in relation to another machine part. The ring electrode and corresponding slip ring can be economically produced and have low wear. The electrode is made of a rod material made of stainless steel, which is rolled into a ring and the free ends of the ring are brought together to form a closed ring.

The invention relates to a ring electrode for a slip ring for transmitting electrical energy between machine parts, of which at least one machine part can be rotated in relation to another machine part. The ring electrode and corresponding slip ring can be economically produced and have low wear. The electrode is made of a rod material made of stainless steel, which is rolled into a ring and the free ends of the ring are brought together to form a closed ring.

A carbonaceous material is fabricated by kneading of carbon powder and a binder. The carbonaceous material is granulated such that an average particle diameter of the carbonaceous material is 0.3 mm or more. A brush material is fabricated by mixing of the granulated carbonaceous material and metallic powder. A ratio of the metallic powder to a total weight of the brush material is adjusted to 1% by weight or more and 30% by weight or less. Pressure molding is performed on the fabricated brush material, and thermal processing is further performed on the brush material at a temperature at which a resin in the brush material is not carbonized.

A carbonaceous material is fabricated by kneading of carbon powder and a binder. The carbonaceous material is granulated such that an average particle diameter of the carbonaceous material is 0.3 mm or more. A brush material is fabricated by mixing of the granulated carbonaceous material and metallic powder. A ratio of the metallic powder to a total weight of the brush material is adjusted to 1% by weight or more and 30% by weight or less. Pressure molding is performed on the fabricated brush material, and thermal processing is further performed on the brush material at a temperature at which a resin in the brush material is not carbonized.