Abstract: An outer diameter of a claw portion is smaller than an outer diameter of a main portion, a radial width of the claw portion is ½ or less of a radial width of the main portion, an axial width from an upper surface of a connection portion of a pillar portion to a bottom surface of the main portion is ½ or less of an axial width of a crown type cage for a ball bearing, and in the main portion, an opening portion is provided between adjacent pockets.

Abstract: According to an electric power steering system of the present invention, a bearing support housing member supporting at least one rolling bearing is preferably formed of a resin which can be continuously used in a temperature environment ranging from ?40° C. to 85° C., which is made of a resin composition containing a fibrous filler ranging from 30% by mass to 55% by mass, which has a coefficient of linear expansion ranging from 1.2×10?5 to 5.5×10?5 (1/° C.) in both a fiber direction and a perpendicular direction to the fiber direction in a temperature range from 23° C. to 80° C., and which has a coefficient of water absorption equal to or less than 4% when being left in water at a temperature of 23° C. for 24 hours.