the hollow part has an opening that opens at {TAIL ~ an end face} on {HEAD ~ a side} opposite the suction part side end face of the rotating shaft, and 
the hollow part has an opening that opens at { TAIL ~ an end face } on { HEAD ~ a side } opposite the suction part side end face of the rotating shaft , and
OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH