Patent ID: 7800276

Claim:
A rotor assembly, comprising: a first rotor including a first interface surface extending from edge to edge of the first rotor; and a second rotor including a second interface surface corresponding to the first interface surface and extending from edge to edge of the second rotor, the first rotor positioned with the first interface surface in direct physical contact with the second interface surface where the edges of the first and second rotors are aligned; where the first and the second rotor each include: an over-molded body of a thermoset material including non-electrically conducting reinforcement materials; an annular U-shaped back iron including a first wall parallel to a second wall; a first annular magnet coupled to an interior surface of the first wall; and a second annular magnet coupled to an interior surface of the second wall, the first and second annular magnets formed of a series of magnets with successive opposite polarities, and extending from the over-molded body.