Abstract: A carbon grounding brush has a sliding surface that slides on and grounds a driving shaft transmitting driving force and exposed to an insulating liquid. A slit is provided on the sliding surface, and at least one end of the slit is located on one side of the sliding surface. The slit introduces into the slit the insulating liquid pressed towards the sliding surface by the rotation of the driving shaft and discharges the insulating liquid from the one end of the slit. Thus, the contact resistance between the driving shaft and the sliding surface is made small, and electrical corrosion and electromagnetic noises are reduced.

Abstract: 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.

Abstract: A brush for a motor for electrical equipment in an automobile includes a main brush portion containing carbon and an abrasive having a Vickers hardness higher than or equal to 10 GPa and lower than or equal to 14 GPa. The sliding noise of the brush is reduced in the brush for a motor for electrical equipment in an automobile.

Abstract: 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 ??·cm. No spark discharges occur if the fuel pump motor is operated to output a high power.

Abstract: A carbon brush for a fuel pump includes a brush body and a lead wire connected to the brush body, and the brush body has carbon and polyether ether ketone as main components. Abnormal wear does not occur even if a fuel pump motor is operated at a high voltage.

Abstract: A carbon brush for a fuel pump includes a brush body and a lead wire connected to the brush body, and the brush body has carbon and polyether ether ketone as main components. Abnormal wear does not occur even if a fuel pump motor is operated at a high voltage.

Abstract: A segment of a carbon commutator includes a carbon layer on a surface side and a metallic carbon layer on a bottom side, and the carbon layer and the metallic carbon layer both contain a thermoplastic resin binder.

Abstract: In a commutator of a rotary electric machine, each of commutator segments has a low-resistive layer made of a low-resistive material and a high-resistive layer made of a high-resistive material having a specific resistance higher than that of the low-resistive material. The low-resistive material contains a carbonic material and a binder. The high-resistive material contains a carbonic material, a binder and an inorganic substance such as boron nitride. A mixing ratio of the inorganic material to the high-resistive material is more than 20 wt %. Alternatively, a brush, which makes contact with the commutator segments, can have the high-resistive layer and the low-resistive layer.

Abstract: A brush body 4 of a metal-graphite brush 2 is composed of a commutator side portion 6 which contains graphite, copper and a metal sulfide solid lubricant, and a lead side portion 8 which contains graphite and copper but does not contain any metal sulfide solid lubricant. A lead wire 10 is attached to the lead side portion 8 containing no metal sulfide solid lubricant.

Abstract: A plane commutator is comprised of a plurality of commutator segments, a plurality of base plate and a resinous boss member. The commutators are made of sintered carbon compound and disposed to provide a plane commutator surface at an end thereof and a base portion at the other end. Each commutator segment has a projection extending from the base portion. The resinous boss member is disposed in contact with the base portion. Each base plate has an engagement hole, to which one of the projections is fitted, and a terminal portion that extends along an outer periphery of the boss member. A powder-accommodation pocket is formed around a foot of each the projection so that the projection can be shaved by a corner edge of the hole. This ensures good contact of the commutators with the metal base plates and provides a sufficient manufacturing tolerance.

Abstract: A sulfidation-resistant current-carrying member, such as a commutator, suitable for a direct-current motor in a fuel pump is provided. The current-carrying member for a direct-current motor in a fuel pump includes a commutator composed of a carbon layer having carbon as a principal component and forming a sliding surface at one end, and a metal carbon layer fixedly bound with the carbon layer at the other end and comprising 55 to 90 wt % of metal having brass as a principal component and a remaining portion having carbon as a principal component. By using brass as a primary metal component in the metal carbon layer, it is possible to achieve a commutator with superior resistance to sulfidation.

Abstract: Ag particles produced by chemical reduction and having a mean particle size of 5 &mgr;m are added by 0.05-3 wt % and Zn are added by 2-10 wt % to a Pb-less brush body containing graphite, Cu and a metal sulfide solid lubricant of a metal-graphite brush.

Abstract: A copper-zinc alloy powder of which zinc content is from 10 to 50 wt % and of which mean particle diameter is from 15 &mgr;m or under is added to a Pb-less brush body comprising graphite, copper and a metal sulfide solid lubricant of a copper-graphite brush.

Abstract: A metal-graphite brush comprises a brush body which is made by mixing and molding metal powder and graphite powder. 2 mg to 30 mg as amounts of phosphate ion of at least one of phosphoric acid and a phosphate compound is added to 1 g of the brush body of the metal-graphite brush.

Abstract: 0.4 to 8 wt % of indium is added to a Pb-less metal-graphite brush containing graphite, copper and a metal sulfide solid lubricant.

Abstract: A brush body 4 of a metal-graphite brush 2 is composed of a Pb-less commutator side portion 6 which contains graphite, copper and a metal sulfide solid lubricant, and a lead side portion 8 which contains graphite, copper, the metal sulfide solid lubricant and Pb.

Abstract: Disclosed is a carbon commutator, comprising a plurality of metal segments each having a through-hole, a plurality of carbon segments each having a projecting portion, which contains a metal, being inserted into the through-hole to be deformed so as to join the carbon segment to the metal segment, and a commutator body on which a plurality of the metal/carbon joined segments are arranged fixedly in a manner to form a substantially circular body.

Abstract: An apparatus has an apparatus body and a support shaft rotatably supported on the apparatus body. An intermediate plate is provided at an intermediate height of the apparatus body with a plurality of dies arranged in a substantially parallel plane where corresponding forming chambers are defined. Relative to those areas corresponding to the forming chambers, upper punches are provided above the intermediate plate in a way to be movable in an up/down direction and lower punches are provided below the intermediate plate in a way to be movable in the up/down direction. The upper punch is held in a raised position in a given timing corresponding to the rotation of the main shaft at which time powder is fed into the forming chamber. When the upper punch is released from being held in a raised position, the upper punch is downwardly driven to allow it to enter into the forming chamber. The lower punch is held in that lowered position where the lower end opening is closed.