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: 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: 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.

Abstract: A Cu—Ni—Sn copper-based sintered alloy has a composition including 10 to 40% by mass of Ni, 5 to 25% by mass of Si, and the remainder containing Cu and inevitable impurities, and if necessary, 0.1 to 0.9% by mass of P, 1 to 10% by mass of C, 0.3 to 6% by mass of calcium fluoride or 0.3 to 6% by mass of molybdenum disulfide. In the structure of the alloy, a phase of a composition containing Cu(4-x-y)NixSny (where x: 1.7 to 2.3, y: 0.2 to 1.3) is dispersed.

Abstract: 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 6, and sintering the powder compact 6. A copper-based raw powder is composed of a copper-based flat raw powder 2 having an average diameter smaller than that of an iron-based raw powder 1 and an aspect ratio larger than that of the iron-based raw powder 1, and a copper-based small-sized raw powder 3 having the average diameter is smaller than that of the copper-based flat raw powder 2. The copper is allowed to segregate at the surface of the sliding part.

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 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: There is provided an oil-impregnated sintered bearing which enable to prevent oil leakage from an outer peripheral surface 7 of an bearing body 2. The oil-impregnated sintered bearing 1 includes a bearing body 2 which is made of a porous sintered alloy containing vacancies 8 and has a bearing hole 3 in which a rotary shaft can be inserted, wherein the vacancies 8 opened on an outer peripheral surface 7 of the bearing body 2 are crushed. The vacancies 8 may be crushed in the state of a green compact P, or in the state of a sintered alloy after sintering the green compact P. Consequently, the oil leakage from the outer peripheral surface 7 of the bearing 1 can be prevented, and oil pressure in the bearing hole 3 can be preserved.

Abstract: 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.

Abstract: The present invention is for providing an oil-impregnant sintered bearing, which can reliably preserve an oil film on a sliding face, and a method for manufacturing the oil-impregnant sintered bearing. An oil-impregnant sintered bearing is made by providing an internal diameter, which a rotating axis member is inserted through, in a bearing main body, formed by a porous sintered alloy having internal pores therein, and providing a sliding face in one region of the inner peripheral face of the internal diameter, the sliding face being obtained by closing the pores which have been opened in the inner peripheral face. The density in a section preserving oil pressure, which extends from the sliding face of the bearing main body toward the outer side of the diameter, is made higher than the density in other sections of the bearing main body.

Abstract: 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.

Abstract: A wear resistant bearing of a motor-type fuel pump includes a sintered body of compacted powders having a blended composition which is composed of 1 to 5% of graphite, 2 to 9% of Cu—P alloy containing 5 to 10% of P, Cu—Ni alloy containing 21 to 26% of Ni, and the balance, in % by weight. The sintered body made of a Cu—Ni based sintering metal has a structure in which pores are dispersed on a basis material of Cu—Ni alloy particles at a porosity within a range of 8 to 18%, and P components and free graphite are distributed on a boundary between the Cu—Ni alloy particles and in the pores, respectively.

Abstract: 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 for 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.

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.

Abstract: A sintered alloy has prolonged life span in a state where it is in contact with pure water. A bearing 5 is made of a Cu-based sintered alloy 51 having excellent corrosion resistance against liquid including sulfur or its compounds. A tetrafluoroethylene resin layer 53 is provided at the external surface of the sintered alloy 51. The Cu-based sintered alloy 51 is covered with a tetrafluoroethylene resin layer 53 having corrosion resistance, so that it is possible to secure high corrosion resistance even when the sintered alloy 51 is in contact with ionized pure water. It is also possible to provide a sintered alloy having prolonged life span while it is in contact with pure water.

Abstract: A sintered alloy that enables the reducing of coefficient of friction and the sealing of pores on a surface thereof and a method of manufacturing the same. A sintered alloy body includes a resin film layer and pores. The pores define a porosity ranging from 2 to 35 volume %, each having an inlet portion and an inside portion, defining a pore inlet diameter and a pore inside diameter respectively. The pore inlet diameter ranges from 10 to 200 &mgr;m, and an average ratio of the pore inlet diameter to the pore inside diameter is at least. Solid lubricant is dispersed in the resin film layer. After forming the layer 3, it is pressed against the sintered alloy body. Thus, the layer enters into the pores to closely contact them, thereby sealing the pores, reducing the coefficient of friction due to the solid lubricant.

Abstract: A sintered copper alloy material product is provided on which a skin (particularly, a skin of a solid lubricant with low adhesion, such as PTFE or molybdenum disulfide) is securely formed on the surface thereof and has good sliding properties and good seizure resistance under unlubricating environments or under corrosive environments. A sintered copper alloy material is processed using a selective chemical etching solution containing a compound of one kind or more selected from the group of consisting of peroxide, peroxocompound, chromic acid and permanganic acid and a compound of one kind or more selected from the group of consisting of phosphoric acid, sulfuric acid, nitric acid, hydrochloric acid, hydrofluoric acid, zirconic hydrofluoric acid, titanic hydrofluoric acid, titanic acid, molybdic acid, tungstic acid, vanadic acid, niobic acid, and organic chelating agent. Thereafter, a lubricating skin is on the surface of the processed material.

Abstract: The present invention is for providing an oil-impregnant sintered bearing, which can reliably preserve an oil film on a sliding face, and a method for manufacturing the oil-impregnant sintered bearing. An oil-impregnant sintered bearing is made by providing an internal diameter, which a rotating axis member is inserted through, in a bearing main body, formed by a porous sintered alloy having internal pores therein, and providing a sliding face in one region of the inner peripheral face of the internal diameter, the sliding face being obtained by closing the pores which have been opened in the inner peripheral face. The density in a section preserving oil pressure, which extends from the sliding face of the bearing main body toward the outer side of the diameter, is made higher than the density in other sections of the bearing main body.