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