Patent ID: 6276836
Filing Date: 2001-08-21
Classification: F16C

Abstract:
A radial ball bearing comprising outer and inner raceways, a plurality of balls rotatably provided between the outer and inner raceways and a cage formed generally in an annular shape and provided with opposite peripheral surfaces and with a plurality of pockets having an opening in the opposite peripheral surfaces and arranged in a circumferential direction of the cage to rotatably hold a plurality of balls each adapted to rotate around a rolling central axis in one of the pockets, each of the pockets having an inner surface which is defined by a pair of axially middle portions opposed to each other, a first spherical concave surface portion connecting the pair of axially middle portions to each other, and second spherical concave surface portions extending from the pair of axially middle portions, respectively, at least one of the axially middle portions being formed with an axially cylindrical surface portion on at least part thereof in an axial middle of the cage, the axially cylindrical surface portion including a peripheral edge portion along the opening on at least one of the peripheral surfaces of the cage, each of the balls having a rolling surface which is, along a track portion, in contact with the outer and inner raceways to provide a distance between the rolling surface and the axial cylindrical surface portions such that the distance is small nearest the track portion and enlarged as the distance is spaced further from the track portion toward the first and second spherical concave surface portions.