is fixed on {HEAD ~ an inner peripheral surface} of {TAIL ~ the second housing} 32 at a middle portion thereof in the axial direction 
of
is fixed on { HEAD ~ an inner peripheral surface } of { TAIL ~ the second housing } 32 at a middle portion thereof in the axial direction
OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH