Patent ID: 7411325

Claim:
A high efficiency combination motor and electronic variable speed drive comprising: a brushless permanent magnet motor that has a rotor and a stator, and an electronic drive inverter that drives said motor by providing synchronous AC power to said stator; said rotor comprising a ferromagnetic backiron and a circumferential array of alternating polarity magnetic poles on said backiron that drives magnetic flux back and forth across an armature air gap; said stator comprising an air core armature with three-phase windings comprised of bundled multiple individually insulated strand conductor wire, said windings are assembled together in a substantially non-ferromagnetic structure that is located in said armature air gap, whereby alternating magnetic flux from said alternating polarity magnetic poles passes through said windings as said rotor rotates; said inverter comprising a pulse modulated semiconductor H-bridge that switches and regulates power to said three-phase windings to accelerate said rotor; each of said three-phase armature windings is serially electrically connected to said H-bridge through one of three inductors respectively, said inductors having windings on a powder core, each said inductor providing an inductance that is at least twice the value of the leg inductance of said three-phase windings.