Abstract: A bearing device for an axle: including a hub wheel; a flange outwardly provided in an outer periphery of the hub wheel in a radial direction; and bolts having serrations provided at their heads. The flange includes through holes formed therein in its circumferential direction such as to pass therethrough in its axial direction, the bolts are attached into the through holes, respectively, in a state where their serrations bite the through holes of the flange, and an annular groove for reducing a biting amount of the serrations of the bolt is formed in an inner peripheral surface of the through hole of the flange.

Abstract: A bearing device for an axle including a hub wheel; a flange outwardly provided in an outer-periphery of the hub wheel in a radial direction; and bolts having serrations provided at their heads. The flange includes through holes formed therein in its circumferential direction such as to pass therethrough ill its axial direction, the bolts are attached into the through holes, respectively, in a state where their serrations bite the trough holes of the flange, and an annular groove for reducing a biting amount of the serrations of the bolt is formed in an inner peripheral surface of the through hole of the flange.

Abstract: The invention has plural plate-like members, each molded by a metal die using a synthetic resin material in a shape having pockets for retaining rolling elements. A shape obtained by mutually connecting each of the plural plate-like members with connecting portions at both ends is a substantially cylinder shape. A shape of a section between both end portions of each plate-like member has a convex warped shape constituting a part of the cylinder by being subjected to a distortion action owing to heat contraction after being molded by the metal die.

Abstract: There is disclosed a die used to mold a cage having a cylindrical body out of a synthetic resin such that the strength of the portion of the molded cage formed by two meeting streams of the injected material is increased. The die comprises die members having parting surfaces in abutment with each other. A mold cavity conforming in shape with the cylindrical body of the cage is formed between the die members. When the die members, are in abutment with each other, a gate and a resin reservoir are formed along one parting surface and outside the mold cavity. The gate and resin reservoir are in communication with the cavity.

Abstract: A ball bearing cage is formed with pockets each having an inwardly curved spherical pocket face similar to a ball in shape. At least one of the pockets has a protrusion projecting inwardly thereof from one of inner and outer circumferential edge portions of the pocket face. A ball bearing comprises balls retained between inner and outer bearing rings and equispaced circumferentially thereof by a cage. The cage is formed with pockets each having an inwardly curved spherical pocket face similar to the ball in shape, at least one of the pockets having a protrusion projecting inwardly thereof from an edge portion of the face close to the fixed one of the rings.