Patent ID: 8476798

Claim:
A tandem arrangement for an electric machine comprising: an outside rotor having two axially spaced-apart sets of circumferentially-disposed permanent magnets; an inside stator having at least two electrically-independent windings, the at least two windings axially spaced apart from one another and disposed relative to the magnet sets to thereby be magnetically coupled to a respective one of the sets of permanent magnets during rotation of the rotor; wherein the stator is provided in two separate pieces, each piece supported from opposite axial sides of the electric machine relative to one another; and wherein the rotor is supported from substantially centrally of the two pieces and a bearing is disposed between a radially-inner portion of the rotor and the stator, the radially-inner portion of the rotor being configured for torque-transmitting engagement with a shaft, the radially-inner rotor portion including two axially spaced-apart sleeve members interconnected by an intermediate member defining an internal cavity unfilled by the shaft during torque-transmitting engagement, at least a portion of the internal cavity having a conical shape.