Patent ID: 7671509
Filing Date: 2010-03-02
Classification: H02K

Abstract:
1. A rotor assembly for a permanent magnet electric generator for generating a three-phase AC, comprising: a three-phase winding disposed inside the electric generator and configured to conduct the three-phase AC; an axially disposed annular outer ring being concentric with an axis of rotation; an axially disposed laminated annular inner ring being concentric with the axis of rotation, the laminated inner ring being formed by a plurality of thin, ring-shaped magnetically permeable material, the inner ring having a radius less than the radius of the outer ring, and the inner ring being disposed inside the outer ring; a rotor frame attached to the inner ring and the outer ring to define a radial gap between the inner and the outer rings; a rotor hub concentric with the axis of rotation and disposed inside the inner ring, the rotor hub being coupled to the inner ring by a hub frame mounted on the rotor hub, the rotor hub adapted to be rotationally coupled to a shaft for rotating the rotor assembly to generate the three-phase AC in the three-phase winding; and a plurality of magnets disposed on the outer ring, each magnet having a north pole and a south pole.