Abstract: A commutator utilizing a carbon composite base material, the carbon composite base material including a carbon base material; and an iron layer. The iron layer, to which a metal material can be joined, is formed on a surface of the carbon base material, iron powders, which are used to form the iron layer, are subjected to a treatment so as to increase surface-adsorbed oxygen before placing the iron powders to the surface of the carbon base material that is formed in advance by sintering, and sintering is applied to the iron powders placed on the surface of the carbon base material at a temperature not less than a diffusion temperature of carbon and not more than a melting point of iron in order to form the iron layer on the surface of the carbon base material.

Abstract: A commutator utilizing a carbon composite base material, the carbon composite base material including a carbon base material; and an iron layer. The iron layer, to which a metal material can be joined, is formed on a surface of the carbon base material, iron powders, which are used to form the iron layer, are subjected to a treatment so as to increase surface-adsorbed oxygen before placing the iron powders to the surface of the carbon base material that is formed in advance by sintering, and sintering is applied to the iron powders placed on the surface of the carbon base material at a temperature not less than a diffusion temperature of carbon and not more than a melting point of iron in order to form the iron layer on the surface of the carbon base material.

Abstract: An object of the present invention is to provide an oil-impregnated sintered sliding bearing which has a large amount of the lubricating oil as a bearing element which has long life, has a small amount of scattered and lost lubricating oil, has a simple structure, and takes up a small space for a bearing. An oil-impregnated sintered sliding bearing includes: an axis; plural porous sintered compacts joined with each other by sizing; a cavity between the sintered compacts at an axial direction center portion; and a gap which continuously extends from an end portion of the cavity and has a width narrower than the cavity, wherein the gap opens to an end surface or a peripheral surface of the bearing.

Abstract: An inclined function material is formed with an iron layer on a surface of a carbon material. This material can be used in a carbon base member and does not limit the choice of desired characteristics in a carbon base member. The process by which the carbon base member is formed also ensures the iron layer is integrated firmly with the surface of the carbon material. A suitable amount of an iron powder having a particle diameter of 5 to 15 &mgr;m is placed directly on the surface of a carbon material, which is sintered in advance under suitable conditions, and stuck to the surface uniformly and flatly. The iron powder and the carbon material are sintered at 1000° C. to 1300° C. and preferably 1050 to 1150° C. for 1 to 2 hours and preferably about 1.5 hours to form a carbon base member in which the iron layer is formed on one surface of the carbon base member.

Abstract: An inclined function material is formed with an iron layer on a surface of a carbon material. This material can be used in a carbon base member and does not limit the choice of desired characteristics in a carbon base member. The process by which the carbon base member is formed also ensures the iron layer is integrated firmly with the surface of the carbon material. A suitable amount of an iron powder having a particle diameter of 5 to 15 &mgr;m is placed directly on the surface of a carbon material, which is sintered in advance under suitable conditions, and stuck to the surface uniformly and flatly. The iron powder and the carbon material are sintered at 1000° C. to 1300° C. and preferably 1050 to 1150° C. for 1 to 2 hours and preferably about 1.5 hours to form a carbon base member in which the iron layer is formed on one surface of the carbon base member.