Patent attributes
A brushless permanent magnet motor has a rotor supported to rotate about an axis of rotation, and a stator that is stationary and magnetically exerts torque upon the rotor. The rotor has a ferromagnetic backiron and a circumferential array of alternating polarity magnetic poles that drive magnetic flux back and forth across an armature airgap. The stator includes an air core armature with windings made of bundled multiple individually insulated strand conductor wire. The windings are assembled together in a non-ferromagnetic structure that is located in the armature airgap, so alternating magnetic flux from the alternating polarity magnetic poles passes through the windings as the rotor rotates. A thin electrically conducting shield is located inside the armature airgap to increase the efficiency of the motor by reducing eddy current losses in the surfaces of the rotor magnets.
