Radial ball bearing retainer

A deep channel type of radial ball bearing having a retainer. The bearing has an outer ring and an inner ring. Running channels are formed on the mutually opposing orbiting surfaces of the outer ring and inner ring. A specified number of balls are fit into the running channels. The retainer having pockets is placed between the outer ring and the inner ring. Each ball is captured in one of the pockets. A ball contact surface is formed on the inner surface of each edge on the opening side of the pockets. A curved ridge line forms the boundary between the inner surface of the pocket and the contact surface. This curved ridge line that forms the boundary is substantially parallel to the direction of rotation of the balls. A channel is formed at the bottom surface of the pocket. The channel extends from the inner perimeter to the outer perimeter of the retainer. The lubricating oil on the bottom surface of the pocket flows through the channel by virtue of the rolling of the balls and is guided to the outer perimeter side. A triangle-shaped fin having an inclined surface is integrally formed between the adjacent pockets on the outer perimeter surface. The inclined surface is formed on the trailing side of pocket with respect to the retainer direction of rotation. Lubricating oil directed from the above-described channel to the outer perimeter surface by the rolling of the ball is received at the inclined surface of the fin and is supplied to the vicinity of the leading edge of the pocket that is located behind the fin by the rotation of the retainer.