In this case, a magnet A having a portion B which does not change the breadth of {HEAD ~ a magnet} in {TAIL ~ the circumferential direction} even if the distance from the center of revolution changes, is arranged 
In this case , a magnet A having a portion B which does not change the breadth of { HEAD ~ a magnet } in { TAIL ~ the circumferential direction } even if the distance from the center of revolution changes , is arranged
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH