Holes of a predetermined depth are formed in an outer peripheral surface of an outer ring. The outer ring is integrally connected to a housing by insert molding, so that a resin, forming the housing, is received in the holes. Alternatively, pins are fixedly inserted respectively in the holes, and are fitted respectively in grooves, notches or through holes formed in the housing. With this construction, a creep is positively prevented without the need for providing an interference fit between the housing and the outer ring.