Patent ID: 9366292
Filing Date: 2016-06-14
CPC Classification: F16C

Claim Text:
1. A retainer for a ball bearing, comprising two annular members that face each other in an axial direction thereof, the two annular members having opposed surfaces each comprising hemispherical pockets that are formed at a plurality of positions in a circumferential direction of each of the two annular members and configured to receive balls, the opposed surfaces being snap-fitted to each other so as to couple the two annular members to each other, wherein the hemispherical pockets each have an inner peripheral surface including a ball contact surface and a ball non-contact surface, wherein the ball contact surface is formed at a central portion in a pocket circumferential direction of the inner peripheral surface and at least at a central portion in a pocket axial direction of the inner peripheral surface, the pocket circumferential direction of the inner peripheral surface being different from the circumferential direction of a corresponding one of the two annular members and the pocket axial direction of the inner peripheral surface being different from the axial direction of the two annular members, wherein the ball non-contact surface comprises a recess that is recessed to an opposite side to a corresponding one of the balls across the ball contact surface, wherein the recess is opened in at least one of pocket axial ends, wherein the ball contact surface comprises an oblong portion formed at the central portion in the pocket circumferential direction of the inner peripheral surface so as to reach both the pocket axial ends, wherein the ball non-contact surface comprises circular-arc recesses provided on both sides of the ball contact surface in the pocket circumferential direction of the inner peripheral surface, and wherein the circular-arc recesses are each opened in both the pocket axial ends.