Abstract: A loading hole made in either of an outer ring and an inner ring is provided in two rows of raceways defined between the outer ring and the inner ring, one to each raceway. The loading hole is set out of the guide surface and, therefore there is no fear that a closure fitted in the loading hole causes any obstacle to the rolling movement of the rollers. The loading hole extends radially of the bearing at a location that a center line of the loading hole lies set-off or biased from a center of the roller. An opening edge of the loading hole is exposed to the raceway in a location out of the guide surface, so that the rollers are allowed to roll smoothly without touching with the innermost edge of the closure.