Abstract: A roller retaining assembly for use in a roller bearing includes a retaining ring provided with a plurality of retainer windows arranged spaced apart one from another along the circumferential direction of the ring and a plurality of rollers each of which is received in an associated one of the plurality of retainer windows. The retainer window is generally rectangular in shape and it has a length and a width which are slightly larger than the length and the diameter of the roller, respectively. The retainer window is provided with a pair of retaining projections at the outer peripheral surface and also at the inner peripheral surface of the retainer ring located at the center in the axial direction of the retainer ring. The shortest distance between the pair of retaining projections is set to be smaller than the diameter of the roller so that the roller is confined in the retainer window at all times.