Diamet Corporation

Mitsubishi Materials Corporation

Denso Corporation

Teruo Shimizu

Tsuneo Maruyama

Tadashi Hazama

Hideki Narisako

Yuji Aoki

Tuneo Maruyama

There is provided 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, which is sintered. A copper-based raw powder is composed of a copper-based flat raw powder whose diameter is 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 whose diameter is smaller than that of the copper-based flat raw powder. The copper is allowed to segregate at the surface of the sliding part. The surface of the bearing is covered with the copper-based small-sized raw powder and the copper-based flat raw powder, thereby the surface coverage ratio of copper can be increased.

Sliding part and method of manufacturing the same

An oil-impregnated sintered which does not damage rotating shaft and itself and has a high durability even in the case that the rotating shaft is inclined in the bearing by a large shear load applied thereto, and a method of manufacturing an oil-impregnated sintered bearing which exhibits center deviation-suppressing action of the bearing satisfactorily by accurately forming a bearing hole in an intermediate completely sintered are disclosed.

Oil-impregnated sintered bearing and method of producing the same

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.

Oil-impregnated sintered bearing and manufacturing method thereof

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. Furthermore, containing calcium fluoride improves the seizure resistance.

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.

Bearing made of sintered copper alloy for a recirculation exhaust gas flow rate control valve

Oil impregnated sintered bearing and manufacturing method thereof

A bearing for a motorized fuel pump is made of a Cu&#x2014;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.

Bearing for motorized fuel pump

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. This rotation transmission assembly has a rotation transmission member formed in a substantially circular plate configuration, in a center of which there is a substantially circular cylinder shaped through hole that is formed by an inner circumferential surface, and that includes a rotation transmission portion located on an outer circumferential portion of the rotation transmission member; and an inner side member that is press-inserted into the through hole, wherein the inner circumferential surface of the rotation transmission member is provided with: a smooth ring-shaped surface that is placed adjacent to one end of the inner circumferential surface; and a plurality of protrusion shaped portions that, taking the ring-shaped surface as a basis, protrude inwards in the radial direction, and extend along a portion of the length in the axial direction of the through hole, and wherein the inner side member and the rotation transmission member mesh with each other within the range in which the protrusion shaped portions extend, and are in surface contact with each other within a range in which the ring-shaped surface extends.

Rotation transmission member, rotation transmission assembly, and gear mechanism

An inner rotor having excellent corrosion resistance, which has an outer gear serving as a component of an internal gear pump, and an outer rotor having excellent corrosion resistance, which has an inner gear engaging with the outer gear. The inner rotor and outer rotor of are made of Cu&#x2014;Ni-based sintered copper alloy that contains 12 to 50% by mass of Ni, 5 to 20% by mass of Sn, 0.5 to 5% by mass of C, and if necessary, further contains 5 to 20% by mass of Zn, 0.1 to 0.9% by mass of P, and a balance being Cu and inevitable impurities.

Inner rotor and outer rotor of internal gear pump

A bearing is manufactured by filling iron-based material powder and copper-based material powder in a filling portion of a mold, compacting those material powder so as to form a green compact, and then sintering the green compact. The copper-based material powder contains flat powder particles, the flat powder particles having a large aspect ratio than particles of the iron-based material powder. The coppers-based powder particles segregate on a sliding surface by vibration. The sliding surface of a bearing is covered with copper, and a ratio of iron increases from the sliding surface toward the inside. Since a rotation shaft slides on the sliding surface covered with copper, a frictional coefficient between the rotation shaft and the sliding surface is reduced, thus enabling a smooth rotation thereof. Simultaneously the usage of iron imparts predetermined strength and durability.

Growing community of inventors

Niigata, Japan

Teruo Shimizu