Patent ID: 6230866
Filing Date: 2001-05-15
Classification: B60H,F01P,F04B,F04D,H02K

Abstract:
An apparatus having a rotatable driven shaft;a driving element driven by the rotatable shaft;a driven element for being selectively coupled to the driving element for a torque transfer with the driving element;a first electromagnetic element on the driving element;a second electromagnetic element on the driven member with the coupling therebetween solely by a magnetic field for the torque transfer with-respect to the rotatable shaft;one of said electromagnetic driving and driven elements comprises a plurality of radially-extending electromagnets; andthe other one of said electromagnetic driving and driven elements comprises a plurality of pole pieces spaced radially from the radially-extending electromagnets to define an air gap therebetween across which magnetic flux may extend;an electric current device providing electrical current only to electromagnets and no substantial current to the pole pieces when generating the magnetic flux.