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.

A sintered metal bearing is formed of a porous body formed through sintering of a compact obtained through compression molding of raw-material power. The sintered metal bearing includes a dynamic pressure generating portion formed on an inner peripheral surface, the dynamic pressure generating portion including dynamic pressure generating groove array regions formed continuously to each other in an axial direction of the sintered metal bearing. The dynamic pressure generating groove array regions each include a plurality of dynamic pressure generating grooves arrayed so as to be inclined with respect to a circumferential direction of the sintered metal bearing. An axial dimension of the sintered metal bearing is set to 6 mm or less, and a density ratio of the sintered metal bearing is set to 80% or more and 95% or less.

A sliding member having a sliding surface that is at least partially formed of a surface of a lubricating member is provided. The sliding member includes: a base body as a sintered body of a compact containing metal powder, the base body being integrated with the lubricating member; and the lubricating member as an injection molded product of a resin composition containing a polyarylene sulfide-based resin and a carbon material.

A porous aerostatic bearing includes a bearing seat and a plurality of porous plunger assemblies. The bearing seat is furnished with a plurality of accommodating holes. By locking the porous plunger assemblies individually into the corresponding accommodating holes, the porous aerostatic bearing with adjustable stiffness can thus be formed, difficulty in maintenance thereof can be lowered, and the entire service expense therefor can be substantially reduced.

A crankshaft with improved seizure resistance is provided. A crankshaft having journals 11 and pins 12 includes a compound layer containing iron and nitrogen on its surface, wherein, in the compound layer, for both the journals 11 and pins 12, the porosity area ratio of the thinner one of a region from the surface to a depth of 3.0 ?m and a region across the total thickness of the compound layer is not higher than 10.0%, and both the journals 11 and pins 12 have such a surface geometry that the arithmetical mean deviation of the primary profile, Pa, is not larger than 0.090 ?m.

To provide a rolling bearing having excellent rust prevention capability and capable of being used for a long period of time in a highly corrosion environment. A rolling bearing 1 utilized for a power generator which generates power from natural energy or for generator equipment has one or more bearing members which form the bearing having a rust prevention film formed in a predetermined region of a surface of a base material. The rust prevention film is formed by a porous film with a sacrificial anode action against the base material in the whole of the predetermined region. The porous film in a part or the whole of the predetermined region is subjected to sealing treatment which impregnates the porous film with a sealing treatment agent from a surface of the porous film. A surface of a sealing treatment body obtained from the porous film subjected to the sealing treatment is subjected to first coating treatment which coats the surface of the sealing treatment body with epoxy resin coating. A coated surface formed by the first coating treatment is subjected to a second coating treatment which coats the coated surface with urethane resin coating. The sealing treatment agent is formed by diluting the epoxy resin coating at a dilution rate of between 15 and 25%.

Linear motion mechanism sealants capable of operating at low torque when engaging in linear motion which are capable of carrying out sealing with respect to fine particulate several m in diameter, and which are side seal units for sealing gaps at a shaft provided at a front end portion and a back end portion of a slider of a linear motion mechanism equipped with said shaft and said slider which carries out reciprocating linear motion on said shaft, the linear motion mechanism side seal units 4 being characterized in that fibrous surfaces of seal members comprising fibrous material are arranged so as to be directed toward said shaft in such fashion as to abut and conform to the cross-sectional shape of said shaft at the front end portion and the back end portion of the slider.

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%.

A bearing structure includes: a shaft; an oil-impregnated bearing that supports the shaft to be rotatable and includes a first sintered metal material having a first density; a bearing holder that supports an outer circumferential surface of the oil-impregnated bearing; and a seal member that is provided at an opening of the bearing holder, wherein the shaft is provided with an annular groove having a side surface portion that has an outer diameter that decreases as the side surface portion separates away from one end surface of the oil-impregnated bearing, and wherein the seal member includes a second sintered metal material having a second density that is lower than the first density of the first sintered metal material.

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.