Cage for radial ball bearing

摘要

A cage for a radial ball bearing formed generally in an annular shape and provided with a plurality of pockets with openings arranged in a circumferential direction to rotatably hold a plurality of balls adapted to rotate around a rolling central axis in the pockets, each of the pockets having an inner surface portion which includes a peripheral edge portions along the opening on the peripheral surfaces of the cage and is formed with an axial cylindrical surface having a central axis placed in the rolling central axis of the ball.