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