The opening portion at 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 {HEAD ~ the diameter} of {TAIL ~ ball} 12 
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The opening portion at 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 { HEAD ~ the diameter } of { TAIL ~ ball } 12
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 OTH HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL OTH