Abstract: There is provided a rolling bearing apparatus which can more disperse stress which concentrates on a root portion of a flange portion formed on an outer circumferential surface of an outer ring as compared with a related art. In a rolling bearing apparatus 1, a surface which continues from a vehicle outer side end face 220 of an outer ring flange portion 22 to an outer circumferential surface 210 of an outer ring main body portion 21 is formed to have a smoothly continuing curved surface 200, and a protruding curved surface 203 which protrudes radially outwards is formed on a part of the curved surface 200.

Abstract: There is provided a rolling bearing apparatus which can more disperse stress which concentrates on a root portion of a flange portion formed on an outer circumferential surface of an outer ring as compared with a related art. In a rolling bearing apparatus 1, a surface which continues from a vehicle outer side end face 220 of an outer ring flange portion 22 to an outer circumferential surface 210 of an outer ring main body portion 21 is formed to have a smoothly continuing curved surface 200, and a protruding curved surface 203 which protrudes radially outwards is formed on a part of the curved surface 200.

Abstract: A rolling bearing device for a wheel includes: a hub wheel including a hub spindle to be assembled with a rolling bearing, a flange formed on the hub spindle, and a bolt hole formed through the flange; a hub bolt to be press-fitted in the bolt hole, in which hub bolt includes a shank formed with a serrated shank portion to press-fitted to bite the bolt hole, an intermediate shank portion and a threaded portion in this order; and an annular ridge formed on an inner circumference of an opening on a press-fit exit side of the bolt hole. The annular ridge have a diameter smaller than that of the bolt hole and comes into contact or close to the intermediate shank portion to clog the bolt hole.

Abstract: A bearing is provided which can be sufficiently processed by a usual NC grinding machine, and attain a life period that is substantially equal to that of a bearing having a theoretical crowning shape which is derived from the elastic contact theory, even when the bearing is used in a portion to which a heavy load or a high torque load is applied. As means for realizing such a bearing, a generating line of a rolling surface of a roller or a raceway surface of an inner or outer race is divided into a plurality of zones, and the shape of the generating line is approximated to a special curve shape which is theoretically derived, by a plurality of circular arcs which are contacted with each other on the border line between the corresponding zones. Therefore, it is possible to obtain a roller bearing which can be practically used, and which can attain a life period that is substantially equal to that of a bearing having an ideal crowning shape.

Abstract: There is provided a roller bearing in which contact stress between a roller and a raceway is uniformized by optimizing a configuration of a clearance between the roller and the raceway. A configuration of an outer circumferential surface (8) of a tapered roller (6) of a tapered roller bearing (1) is defined so that a clearance of Y(x)=kYp(x), which results from multiplying an equation Yp(x) for uniformizing contact stress between infinite-width plate and tapered roller by a positive number k=1.5-10, is formed between the raceway surface (4, 5) and the outer circumferential surface (8) of the tapered roller (6). The tapered roller (6) relaxes concentration of contact stresses, improving the durability.