{HEAD ~ Coupling mechanism} 10 includes a driving arm 11 directly coupled to output shaft 5, {TAIL ~ a driven arm} 12 directly coupled to shaft 3, and an elastic coupling member 13 for elastically coupling driving arm 11 to driven arm 12 
includes
{ HEAD ~ Coupling mechanism } 10 includes a driving arm 11 directly coupled to output shaft 5 , { TAIL ~ a driven arm } 12 directly coupled to shaft 3 , and an elastic coupling member 13 for elastically coupling driving arm 11 to driven arm 12
HEAD HEAD HEAD HEAD HEAD HEAD OTH REL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL 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