If a shock greater than the ordinary shock is given to the internal gear 3, according to {HEAD ~ the flexibility} of {TAIL ~ the internal gear} 3, it flexes itself radially to absorb the shock 
If a shock greater than the ordinary shock is given to the internal gear 3 , according to { HEAD ~ the flexibility } of { TAIL ~ the internal gear } 3 , it flexes itself radially to absorb the shock
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 TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH