Patent attributes
A rotation support device for a compressor pulley, wherein a three-point contact radial ball bearing (14b) is used as a rolling bearing for supporting a driven pulley, the cross sectional shape of an inner ring raceway track (19b) coming into contact, at one point, with the rolling contact surface of each ball (17a) is formed in a composite arc by smoothly and continuously connecting arcs with different radii of curvature R1 and R2 to each other, and the radius of curvature R1 on a center side in the width direction is made smaller and the radii of curvature R2 on the both end sides in the width direction are made larger (R1<R2) whereby the durability of the rolling bearing for supporting the driven pulley can be assured while reducing the size of the rolling bearing.
