REVOLVING SEAT BEARING

PROBLEM TO BE SOLVED: To provide a double row four point contact ball bearing capable of equalizing load acting on an upper end of an outer ring. SOLUTION: A contact angle α1between a steel ball 8 and an inner circumference surface 6 of the outer ring 5 is set larger than contact angle α2between the steel ball 8 and an outer circumference surface 3 of an inner ring 2. A distance dm1from a center position of the inner ring 2 to a center position H of the steel ball 8 at an upper end 12 side is set larger than distance dm2from the center position of the inner ring 2 to a center position H of the steel ball 8 at a lower end 13 side. A load acting on a front side of the upper end 42 of the outer ring 5 is dispersed and equalized to reduce load acting on a rear side of the upper end 42 of the outer ring 4. A load acting on the upper end 42 of the outer ring 5 can be dispersed to the steel balls 8 of the double rows. Consequently, a larger load can be born. COPYRIGHT: (C)2009,JPO&INPIT