The compensating device 2, wherein said sleeve is provided with two symmetrical cams , and said support section is provided with {HEAD ~ two ball bearings} that are arranged to roll respectively on said two symmetrical cams during rotational motion of {TAIL ~ said support section}  
The compensating device 2 , wherein said sleeve is provided with two symmetrical cams , and said support section is provided with { HEAD ~ two ball bearings } that are arranged to roll respectively on said two symmetrical cams during rotational motion of { TAIL ~ said support section }
OTH OTH OTH 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 OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH