RETAINER FOR BALL BEARING, AND BALL BEARING

摘要

Provided are a retainer for a ball bearing and a ball bearing, which are capable of reducing torque. The retainer for a ball bearing comprises two annular members that face each other in an axial direction thereof. The two annular members have 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 are snap-fitted to each other so as to couple the two annular members to each other. The hemispherical pockets each have an inner peripheral surface provided with a ball contact surface and a ball non-contact surface. 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 ball non-contact surface comprises a recess that is recessed to an opposite side to corresponding one of the balls across the ball contact surface. The recess is opened in at least one of pocket axial ends.