{HEAD ~ magnetic pole detecting means} disposed in {TAIL ~ an internal space} of the housing member for detecting the position of a magnetic pole on the permanent magnet member 
disposed in
{ HEAD ~ magnetic pole detecting means } disposed in { TAIL ~ an internal space } of the housing member for detecting the position of a magnetic pole on the permanent magnet member
HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH