{HEAD ~ The opening portion} at {TAIL ~ the side} of inner ring 10 formed at the edge portions of two holding surfaces 16 adjacent in the circumferential direction is smaller in size in the circumferential direction than the diameter of ball 12 
{ HEAD ~ The opening portion } at { TAIL ~ the side } of inner ring 10 formed at the edge portions of two holding surfaces 16 adjacent in the circumferential direction is smaller in size in the circumferential direction than the diameter of ball 12
HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH