A sintered bearing bush material for a sliding bearing may include: 0.5 to 1.7 percentage by weight carbon; 0.2 to 1.2 percentage by weight manganese; 0.2 to 1.2 percentage by weight sulphur; 1.2 to 2.4 percentage by weight nickel; 1.0 to 2.1 percentage by weight molybdenum; 3.0 to 7.0 percentage by weight copper; 0.2 to 1.2 percentage by weight tin; 0 to 0.8 percentage by weight phosphorus; and a residual component.

The method comprises depositing a coating of metal material on the inside surface of the body (4) of the stator (36), impregnating said coating with a self-lubricating composite material (20), machining internal cells (28) in the thickness of the coating (10), and machining orifices (34) leading into the cells.

Provided is a bearing for a motor-type fuel injection pump. This bearing is composed of a Cu—Ni-based sintered alloy, inexpensive and has a superior corrosion resistance and abrasion resistance. The bearing contains 10 to 20% by mass of Ni, 2 to 4.5% by mass of Sn, 0.05 to 0.4% by mass of P, 2 to 7% by mass of C, and a remainder consisting of Cu and inevitable impurities. The bearing has a metal structure where Sn is uniformly dispersed and distributed in a metal matrix, and has a porosity of 7 to 17% where a free graphite is dispersed and distributed in pores.

A rolling-element bearing includes a first ring element, a second ring element, a plurality of rolling elements rotatably disposed between the first ring element and the second ring element, and an electrically insulating layer on a surface of the first ring element. The electrically insulating layer is a ceramic layer containing a mixture of aluminum oxide (Al.sub.2O.sub.3) and titanium oxide, and the insulating layer includes titanium compounds that contain reduced titanium oxide (TiO.sub.x) and/or metallic titanium (Ti), and the insulating layer further includes a cured synthetic resin sealer.

On an inner peripheral surface of a bearing hole into which a shaft is inserted, concave oil supply surfaces arranged dispersively like separated islands and a sliding surface continuous around the oil supply surfaces to hold an outer peripheral surface of the shaft are formed: a maximum height difference between the sliding surface and the oil supply surfaces is not less than 0.01% and not more than 0.5% of an inner diameter Di of the sliding surface; a surface aperture area ratio of pores at the sliding surface is not more than 10%; a surface aperture area ratio of pores at the oil supply surfaces is more than 10% and less than 40%; and an area of each of the oil supply surfaces is not less than 0.03 mm.sup.2 and not more than 0.2Di.sup.2 (mm.sup.2).

A sintered bearing exhibits a less of a hard iron alloy phase, and has an excellent wear resistance and cost performance under low-revolution and high-load use conditions. The sintered bearing contains Cu: 10 to 55% by mass, Sn: 0.5 to 7% by mass, Zn: 0 to 4% by mass, P: 0 to 0.6% by mass, C: 0.5 to 4.5% by mass and a remainder composed of Fe and inevitable impurities. An area ratio of a free graphite dispersed in a metal matrix of the bearing is 5 to 35%; an area ratio of a copper phase in the metal matrix of a bearing surface is not less than 30%; a porosity thereof is 16 to 25%; a hardness of an iron alloy phase in the matrix is Hv 65 to 200; and raw material powders employ at least one of a crystalline graphite powder and a flake graphite powder each having an average particle size of 10 to 100 m.

Provided is a novel sintered oil-impregnated bearing superior in wear resistance and cost performance under a severe use condition where the bearing collides with a shaft due to a high load and vibration, such as a condition associated with an output shaft of an electric motor installed in a vehicle and a wiper motor installed therein. The sintered oil-impregnated bearing contains: 15 to 30% by mass of Cu; 1 to 4% by mass of C; and a remainder consisting of Fe and inevitable impurities, in which a metal structure with copper being melted therein is provided at least on a bearing surface; pearlite or a pearlite with ferrite being partially scattered therein is provided in a matrix; a copper-rich phase arranged in a mesh-like manner is also provided in the matrix; and a free graphite is dispersed and distributed in the matrix as well.

An oil-retaining sintered bearing in which friction coefficient can be reduced and a sliding property as a bearing can be improved by supplying a sufficient amount of oil to a sliding surface and preventing the supplied oil from moving to an interior from the sliding surface; a sliding surface 3 supporting an outer peripheral surface of a shaft and a helical oiling surface 4 around a shaft axis of a bearing hole are adjacently formed on an inner peripheral surface of the bearing hole into which the shaft is inserted; a surface open rate at the sliding surface 3 is not larger than 10%; and a surface open rate at the oiling surface exceeds 10%.

Systems and methods of making a cast steel alloy crankshaft for an internal combustion engine are provided. The method comprises providing a mold of the crankshaft. The mold has cavities to form the crankshaft. The method further comprises melting a first metallic material at between 1400 degrees Celsius ( C.) and 1600 C. to define a molten metallic material. In addition, the method further comprises feeding the molten metallic material at a riser connection angle of between 30 and 75 in the cavities of the negative sand cast mold. The method further comprises cooling the molten metallic material at a solidification time of between 5 seconds (sec) and 20 sec in the negative sand cast mold with at least one chill member to define a solidified metallic material having dimensions of the cast steel alloy crankshaft. Furthermore, the method comprises separating the solidified metallic material from the negative sand cast mold to define the cast steel alloy crankshaft.

In order to supply sufficient amount of oil to one or more sliding surfaces and to prevent the supplied oil from moving from the sliding surface(s) to an inside so as to achieve lower friction and improve sliding performance of a bearing, in an oil-impregnated sintered bearing 1, sliding surfaces 3 supporting an outer circumferential surface of a shaft 11 and an oil supply surface 4 in which a diameter is larger than that of the sliding surfaces 3 are formed on an inner circumferential surface of a bearing hole 2 into which the shaft 11 is inserted, to be adjacent in an axial direction of the bearing hole 2, a height gap d1 between the sliding surfaces 3 and the oil supply surface 4 is not less than 0.01% and not more than 15% of an inner diameter of the sliding surfaces, a surface opening percentage of the sliding surfaces 3 is not higher than 10%, a surface opening percentage of the oil supply surface 4 is higher than 10%, and an average circle-equivalent diameter of opening parts of pores on the sliding surfaces is not larger than 20 m.