Abstract: A sliding part in which a surface coverage ratio of copper in the sliding part increases. A bearing which is the sliding part is formed by filling the raw powder into the filling portion of the forming mold, compacting the raw powder to form a powder compact, and sintering the powder compact. A copper-based raw powder is composed of a copper-based flat raw powder having an average diameter smaller than that of an iron-based raw powder and an aspect ratio larger than that of the iron-based raw powder, and a copper-based small-sized raw powder having the average diameter is smaller than that of the copper-based flat raw powder. The copper segregates at the surface of the sliding part. In the bearing in which the copper-based flat powder segregates at the surface, the surface is covered with the copper-based small-sized raw powder that has emerged on the surface, as well as the copper-based flat raw powder, thereby it is possible to increase the surface coverage ratio of copper.

Abstract: A method for forming a compact from a powder wherein a forming portion 1A in a mold body 2 is filled with a raw powder and upper and lower punches 3,4 are fitted into the forming portion 1A to form the compact. Prior to filling the forming portion 1A with the raw powder M, a solution L with a lubricant being uniformly dissolved in a solvent is applied to a peripheral portion of the forming portion 1A, and then the solution is evaporated, thus forming a crystallized layer B thereon. Thus, the reduction of a force for ejecting the compact is realized, while improving the density of the compact, realizing the stable and successive production of the compact.

Abstract: A method for producing a soft magnetic metal powder coated with a Mg-containing oxide film, comprising the steps of adding and mixing a Mg powder with a soft magnetic metal powder which has been subjected to heating treatment in an oxidizing atmosphere at a temperature of 40 to 500° C. to obtain a mixed powder, and heating the mixed powder at a temperature of 150 to 1,100° C. in an inert gas or vacuum atmosphere under a pressure of 1×10?12 to 1×10?1 MPa, while optionally tumbling; and a method for producing a composite soft magnetic material from the soft magnetic metal powder coated with a Mg-containing oxide film.

Abstract: A bearing with strength and abrasion resistance for a flow rate control valve of an exhaust gas recirculation system of an internal combustion engine. By using a sintered Cu alloy with a composition consisting of, by mass %, Ni: 10 to 30%, Sn: 5 to 12%, C: 3 to 10%, P: 0.1 to 0.9% and Cu and inevitable impurities as the balance, the bearing exhibits a thermal expansion coefficient corresponding to that of a shaft made of austenitic stainless steel. As a result, a bearing with strength and abrasion resistance under high temperature conditions is obtained.

Abstract: There is provided an oil-impregnated sintered bearing which enable to prevent oil leakage from an outer peripheral surface of an bearing body. The oil-impregnated sintered bearing includes a bearing body which is made of a porous sintered alloy containing vacancies and has a bearing hole in which a rotary shaft can be inserted, wherein the vacancies opened on an outer peripheral surface of the bearing body are crushed. The vacancies may be crushed in the state of a green compact, or in the state of a sintered alloy after sintering the green compact. Consequently, the oil leakage from the outer peripheral surface of the bearing can be prevented, and oil pressure in the bearing hole can be preserved.

Abstract: There is provided an oil-impregnated sintered bearing which enable to prevent oil leakage from an outer peripheral surface of an bearing body. The oil-impregnated sintered bearing includes a bearing body which is made of a porous sintered alloy containing vacancies and has a bearing hole in which a rotary shaft can be inserted, wherein the vacancies opened on an outer peripheral surface of the bearing body are crushed. The vacancies may be crushed in the state of a green compact, or in the state of a sintered alloy after sintering the green compact. Consequently, the oil leakage from the outer peripheral surface of the bearing can be prevented, and oil pressure in the bearing hole can be preserved.

Abstract: In an internal gear pump of the present invention, a first angle that is formed by a first straight line that connects a rotation axis of an inner rotor to a tooth tip portion of an external tooth in the rotational direction of the inner rotor and an outer rotor, and a second straight line that connects the rotation axis to a meshing portion of the external tooth is not less than 1.4 times the size and not more than 1.8 times the size of a second angle that is formed by a third straight line that connects the rotation axis to a tooth bottom of the external tooth, and the second straight line.

Abstract: A bearing for a motorized fuel pump is made of a Cu—Ni based sintered alloy, composed of: 21 to 35% by mass of Ni, 5 to 12% by mass of Sn, 3 to 7% by mass of C, 0.1 to 0.8% by mass of P, and the balance of Cu and inevitable impurities. A matrix of the bearing is formed with pores with a porosity of 8 to 18%, and the P component is predominantly included at the grain boundary, and free graphite is distributed along the insides of open pores that are open to the surface and extending into the bearing. In this bearing, a Sn rich alloy layer containing equal to or more than 50% by mass of Sn is formed on the insides of the open pores and near openings of the open pores.

Abstract: An outer stator is provided in a reciprocating engine together with an inner stator and a mover, that has a cylindrical shape and is placed around the mover coaxially with an axis of the mover, and that forms a magnetic path between itself and the inner stator via a field magnet of the mover, the outer stator includes an aperture portion that is formed in an inner circumferential surface thereof that faces the mover; an internal space that opens via the aperture portion, and in which a wound wire coil is placed; and undercut portions that, in a cross section including the axis, are provided at both end positions along the axis, and that are recessed from the inner circumferential surface towards the outer side in a radial direction.

Abstract: A method for forming a compact from a powder wherein a forming portion 1A in a mold body 2 is filled with a raw powder and upper and lower punches 3,4 are fitted into the forming portion 1A to form the compact. Prior to filling the forming portion 1A with the raw powder M, a solution L with a lubricant being uniformly dissolved in a solvent is applied to a peripheral portion of the forming portion 1A, and then the solution is evaporated, thus forming a crystallized layer B thereon. Thus, the reduction of a force for ejecting the compact is realized, while improving the density of the compact, realizing the stable and successive production of the compact.

Abstract: There is provided a rotation transmission assembly that can be produced in large quantities and at low cost and has an anti-rotation function and an anti-release function.