Abstract: A ball bearing which is to function as a radial, radial angular-contact, and axial angular-contact bearing includes coaxial inner and outer races respectively formed with ball grooves which face each other, the bearing having a plurality of balls of a given ball radius situated between these races and extending into the grooves thereof so as to have rolling contact with the races. At least one of these races has in an axial plane which contains the common axis of the races a cross-sectional configuration according to which the innermost part of the groove of this one race has a radius of curvature which is somewhat greater than the radius of the ball, e.g., about 51.6% of the diameter of the ball, with the radius of curvature of the latter groove gradually increasing from the innermost part thereof up to a pair of opposed side edges of the groove.

Abstract: The roller bearing seal includes a ring-shaped member integrally connected to an outer race of the roller bearing. The ring-shaped member has an outer lip portion that is spaced a predetermined amount from the inner race of the roller bearing so as to provide a gap between the ring shaped seal member and the inner race. Oppositely extending rim portions project from the lip portion in concentric fashion with respect to the lip portion to define respective spaces for accommodating grease layers. The grease layers and the lip portion constitute a seal against the inner race thereby preventing dust or other foreign particles from passing through the grease layers and the lip portion.