Patent ID: 7466053
Filing Date: 2008-12-16
Classification: H02K

Abstract:
1. An electric traction motor comprising: an outer rotor arranged as a motor armature, said outer rotor including a hollow substantially cylindrical laminated armature core, a plurality of armature windings imbedded in a plurality of parallel inside slots of said armature core respectively for producing a revolving magnetic field, a first outer rotor side flange and a second outer rotor side flange attached coaxially to both sides of said armature core respectively and firmly tightened together with the armature core, and an outer rotor shaft firmly attached coaxially to said second outer rotor side flange and extending outside the second outer rotor side flange; an inner rotor arranged as a motor field, said inner rotor including a substantially cylindrical field core, a plurality of permanent magnets imbedded in a plurality of parallel outside slots of said field core respectively for producing a permanent magnetic field, and an inner rotor shaft coupled with the field core, rotatably supported coaxially inside the outer rotor, and extending outside said first outer rotor side flange; a stationary motor enclosure, including a central substantially cylindrical motor enclosure, a first motor enclosure side flange and a second motor enclosure side flange firmly attached to both sides of said central cylindrical motor enclosure respectively, wherein said inner rotor shaft is rotatably supported in said first motor enclosure side flange coaxially to the central cylindrical motor enclosure and said outer rotor shaft is rotatably supported in said second motor enclosure side flange coaxially to the central cylindrical enclosure; an electric motor controller for operating said electric traction motor, including control of the direction and magnitude of the electric current through the windings of said motor armature, wherein said motor controller is arranged to produce via the motor armature an electromagnetic field revolving in relation to said outer rotor, and wherein the interaction between said revolving electromagnetic field of the outer rotor and said permanent magnetic field of said inner rotor propels said two rotors to rotate in opposite directions, and a first outer rotor axial fan integrated within the first outer rotor side flange and a second outer rotor axial fan integrated within the second outer rotor side flange, said two outer rotor axial fans operating in series and producing a continuous internal close-loop air circulation between the inner and outer rotors and between the outer rotor and said motor enclosure, for improving the rate of heat transmission from both rotors to the motor enclosure when the outer rotor rotates.