Patent ID: 7296409

Claim:
An AC induction motor, comprising: a stator having motor field coils which generate a rotating magnetic field when energized by an AC control signal which induces electric current flow in a rotor to generate a rotor magnetic field which interacts with the stator magnetic field to rotate said rotor about an axis, the electric flow induced in the rotor which generates said rotor magnetic field comprising eddy currents, and wherein the field coils are arranged in an annular array adjacent first and second axial surfaces of the rotor and the maximum diameter of the rotor is smaller than the outer diameter of the annular coil array such that eddy currents are induced in the rotor which flow from one axial side of the rotor to the other across the peripheral edge of the rotor; and wherein the motor field coils are energized by a fixed frequency AC control signal such that the motor has a predetermined synchronous speed.