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.