The object of the invention is achieved by the fact that {HEAD ~ the magnetic rotor} is covered with {TAIL ~ a thin, corrosion stable, tightly fitting metal sleeve} in the area of the magnets 
is covered with
The object of the invention is achieved by the fact that { HEAD ~ the magnetic rotor } is covered with { TAIL ~ a thin , corrosion stable , tightly fitting metal sleeve } in the area of the magnets
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH