The internal gear is made of an elastic resin and is separated from the casing of the system or {HEAD ~ a metal ring} fitted in {TAIL ~ the casing} by a predetermined gap 
The internal gear is made of an elastic resin and is separated from the casing of the system or { HEAD ~ a metal ring } fitted in { TAIL ~ the casing } by a predetermined gap
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH