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.
