Abstract: A seal device of a vehicle wheel-bearing unit includes a leak prevention seal lip and a scatter prevention seal lip, wherein a front end part of the leak prevention seal lip is in slidable contact with an axially inboard surface of a rotational-side flange in a state of having an interference throughout an entire circumference, and an axially middle part of the scatter prevention seal lip is provided at a radially more outer position than an indifferentiable part that is present between an axially inboard surface of a thick wall part and an axially inboard surface of a thin wall part and in a state where the axially middle part of the scatter prevention seal lip is radially overlapped with the indifferentiable part.

Abstract: A full complement angular ball bearing with no cage and having a contact angle from 10 to 45° and an increased number of balls for use under severe conditions. The life is extended by defining the surface roughness of the inner ring and the outer ring, defining the roughness ratio of them relative to the rolling element, defining the Cr content in the alloy steel for the rolling element, forming the rolling element with oxide ceramics, or providing a dense nitride layer on the surface of the rolling element, avoiding the presence of particles with a mean diameter in excess of 3 ?m on the raceway surfaces of the outer ring and the inner ring, or coating a film of a hardness higher than that of the raceway surface of the outer ring and the inner ring on the surface of the rolling element.

Abstract: At least any one of a bearing member (inner race, outer race and rolling element) is formed with a steel material containing 0.2 to 1.2 wt % of C, 0.7 to 1.5 wt % of Si, 0.5 to 1.5 wt % of Mo, 0.5 to 2.0 wt % of Cr, and 12 ppm or less of O. The bearing member is treated with carbonitriding, and thereafter, quenching and tempering so as to provide carbon concentration in the steel surface being 0.8 to 1.3 wt % and nitrogen concentration on the same being 0.2 to 0.8 wt %.

Abstract: A rolling bearing 1 in which a plurality of rolling elements 4 are disposed between bearing rings comprising a fixed ring 2 and a rotational ring 3 intended for prolonging the rolling life of a rolling bearing used at high temperature, large vibrations and heavy load such as in engine auxiliaries, wherein a tempering treatment is applied after quenching to at least one of the fixed ring 2 or the rotational ring 3 containing: C=0.65-1.25%, Si=0.7-2.5%, Cr=0.5-3.0% and containing at least one of: Mo=0.5-3.0% and Ti=0.05-0.5%, to dispersingly precipitate Mo type carbides or Ti type carbide of 50 to 300 nm size finely, to obtain a hydrogen trapping effect with the Mo type or Ti type carbides at the rolling surface thereby suppressing and preventing intrusion of hydrogen in the vicinity of the maximum shearing stress position, as well as suppressing and preventing occurrence and extension of fine initial cracks by the dispersing precipitation of the fine Mo type carbides.

Abstract: As a steel material for an inner race, an outer race and a rolling element constituting a rolling bearing, there is used one containing carbon (C) and chromium (Cr) in an amount of 0.65 wt % to 1.10 wt % and 2.0 wt % to 6.0 wt %, respectively. At least one of the inner race, the outer race and the rolling element is formed from the steel material. The inner race, outer race and the rolling element thus formed is then subjected to hardening, tempering and polishing. Further, a chromium oxide layer (Cr2O3) having a thickness of 5 nm to 300 nm is formed on a race track surface of at least one of the inner race, the outer race and the rolling element. If the rolling bearing is used in operation under the lubrication at a high traction coefficient with water mixed therein, finely particulate molybdenum carbide and/or vanadium carbide having a particle diameter of 50 nm to 300 nm is distributed in the matrix.

Abstract: A rolling bearing comprises races including an inner race and an outer race formed of an alloy steel material; and a plurality of rolling elements formed of a ceramic material and interposed between the inner race and the outer race in such a manner as to be capable of rolling, wherein at least one of the inner race and the outer race is formed of an alloy steel containing 0.7-1.5 wt. % Si, 0.5-2.0 wt. % Cr, and 0.5-2.0 wt. % Mo in a steel, and is subjected to carbonitriding treatment on the surface of the alloy steel material. The rolling bearing excels in the durability and heat resistance even if it is used in a high-temperature high-speed environment, and does not cause a noise fault.

Abstract: A ball bearing in which races are well prevented from flaking in early stages under an environment using lubricating oil having a high traction coefficient so that a long life of the ball bearing is attained, while the cost of the bearing is reduced. The ball bearing has a plurality of balls disposed between a fixed race and a rotating race, and the ball bearing is used under an environment using lubricating oil having a traction coefficient of 0.07 or more under the conditions that a slip factor is 5% and a temperature is 40.degree. C. At least the groove radius of the rotating race is set to be in a range of from 0.53 Dw to 0.58 Dw both inclusive when Dw designates the diameter of balls. In addition, the hardness of the race is set to be in a range of from HRC 58 to HRC 64 both inclusive.

Abstract: A rotating shaft 4 is attached to an inner race 1, and an outer race 2 is fixed to a housing 5 so that the bearing is operated by the rotation of the rotating shaft 4. In this case, the inner race 1 is made to be the race on the rotating side, and the outer race 2 is made to be the race on the non-rotating side. The raw material composing the inner race 1, outer race 2 and rollers 3 is manufactured from alloy steel containing 4.5 weight % or less of Ni, and 0.5 weight % or less of Cu, and the average value of the Cu equivalent of the rollers 3 and the inner race 1 is set at a value higher than the Cu equivalent of the outer race 2. Thus, even in humid environments where water infiltrates into the lubricant, it is possible to make the rolling bearing have the same durable life as with rolling bearings which are used in normal environments.

Abstract: Disclosed is a rolling bearing comprising races and rolling elements, in which at least one of the races and the rolling elements has at least one of a carbide and a carbonitride precipitated in a surface layer thereof, inclusive of a cutting allowance, wherein the finished surface of at least one of the races and the rolling elements has a hardness of Hv600 to Hv700 at 300.degree. C. The rolling bearing has reliable wear resistance under severe conditions and thereby having an extended bearing life.

Abstract: An object of this invention is to provide a rolling bearing in which, as for the rolling elements, it is unnecessary to employ a high level heat treatment such as carburizing or carbonitriding which requires a long period of time to achieve, and which is sufficiently long in service life even when used with a lubricant containing foreign matters. In a rolling bearing, the amount of residual austenite (.gamma..sub.R vol %) in the surface layer of at least one of the inner and outer races is in a range of 25 to 40 vol %, and the surface hardness (Hv) thereof meets the following condition:-4.7.times.(.gamma..sub.R vol %)+900.ltoreq.Hv.ltoreq.-4.7.times.(.gamma..sub.R vol %)+1000and the hardness of the rolling elements combined with the inner and outer races is higher by H.sub.R C 1 to 2 than that of the one of the inner and outer races.

Abstract: A rolling bearing is disclosed, which comprises an inner ring, an outer ring, and rolling elements each composed of an alloy steel which are, after being subjected to a carburizing treatment or a carbonitriding treatment, subjected to quench-hardening and tempering or is subjected to quench-hardening or tempering, wherein the alloy steel contains from 0.10 to 1.00% by weight C, from 0.50 to 3.00% by weight Cr, from 0.15 to 1.00% by weight Si, from 0.2 to 1.50% by weight Mn, and rest being Fe and unavoidably intermixed impurities, the average amount of the retained austenite of at least the inner ring in the inner ring and the outer ring is not more than 4% by volume and the average amount of the retained austenite of the rolling elements is from 20 to 30% by volume.