Patent ID: 6531799
Filing Date: 2003-03-11
Classification: H02K

Abstract:
An electric machine comprising:a pair of rotors which are rotatably disposed upon a shaft, each of said rotors having a plurality of permanent magnets, which collectively generate a first magnetic flux, and a plurality of soft magnetic portions which act as consequent poles and which collectively generate a second magnetic flux, wherein said plurality of permanent magnets and said plurality of soft magnetic portions are disposed in an alternating arrangement to form an outer ring and an inner ring which are concentric to said shaft, said inner ring being oriented relative to said outer ring whereby each permanent magnet disposed within said inner ring is radially aligned with a unique one of said plurality of soft magnetic portions disposed within said outer ring; a stator assembly fixedly disposed between said rotors, and having a winding and a core; and at least one coil, said coil being fixedly disposed in relative close proximity to said pair of rotors, said coil being selectively energizable, said energization being effective to controllably vary said second magnetic flux.