Abstract: An electric machine for converting between electrical and rotary mechanical energy includes a rotor journaled to rotate about an axis of rotation, and a stationary stator mounted adjacent to the rotor. The stator has a ferromagnetic backiron with a surface facing the rotor across a magnetic airgap and having windings applied in a winding pattern formed directly onto the stator backiron and adhered to its surface with a pre-applied tacky adhesive. The windings magnetically exert torque upon the rotor across the magnetic armature airgap in response to electric power applied to the windings. The rotor has permanent magnets that generate magnetic flux across the airgap and through the windings. The windings are comprised of pre-bundled multiple individually insulated conductor strands that are electrically connected in parallel but are electrically insulated from each other along their lengths inside said magnetic armature airgap.

Abstract: A process for assembling a brushless motor-generator includes assembling a rotor formed from two spaced apart rotor portions having magnetic poles that drive magnetic flux circumferentially through the rotor portions and back and forth across an armature airgap formed between the rotor portions. An air core armature is formed by coating a substantially nonmagnetic armature form with a tacky adhesive layer, and winding armature windings into a winding pattern onto the substantially nonmagnetic form using wire made of multiple individually insulated conductor strands that are electrically connected in parallel but are electrically insulated from each other along their length when located inside the armature airgap, wherein the strands of said wire are diametrically held together by an outer serve. The winding of the armature form includes sequentially applying pressure to sections of said wire against the tacky adhesive layer.

Abstract: A process for assembling a brushless motor-generator includes assembling a rotor formed from two spaced apart rotor portions having magnetic poles that drive magnetic flux circumferentially through the rotor portions and back and forth across an armature airgap formed between the rotor portions. An air core armature is formed by coating a substantially nonmagnetic armature form with a tacky adhesive layer, and winding armature windings into a winding pattern onto the substantially nonmagnetic form using wire made of multiple individually insulated conductor strands that are electrically connected in parallel but are electrically insulated from each other along their length when located inside the armature airgap, wherein the strands of said wire are diametrically held together by an outer serve. The winding of the armature form includes sequentially applying pressure to sections of said wire against the tacky adhesive layer.

Abstract: An air core motor-generator has a rotor that rotates about an axis of rotation, and a stationary stator that magnetically applies torque to the rotor. The rotor includes magnetic poles that drive magnetic flux across an armature airgap. The stator has an air core armature located in the armature airgap, with windings such that the magnetic flux across the airgap penetrates directly transversely through the windings and induces an AC voltage in the windings as the rotor rotates. The armature windings are wound with wire that is assembled of a stack of multiple individually insulated ribbon conductors connected in parallel to form said wire. The ribbon conductors having a narrow thickness and a width substantially greater than said thickness. The armature is oriented in the airgap with the width of the ribbon conductors extending in the direction across the airgap and oriented parallel to the flux direction.

Abstract: A motor-generator includes a rotor that rotates about an axis of rotation, and a stator that is stationary and magnetically interacts with the rotor. The rotor is constructed of two spaced apart rotor portions having magnetic poles that drive magnetic flux across an armature airgap formed therebetween. An armature, located in the armature airgap, has a substantially nonmagnetic and low electrical conductivity form onto which wire windings are wound. The form has a free end that extends inside the rotor, and a support end that attaches to the stationary portion of the motor-generator. The form is constructed with a thin backing portion and thicker raised portions extending from the backing portion in the direction of the magnetic flux. The wire windings have multiple individually insulated conductor wire. The conductors of a single wire are electrically connected together in parallel and electrically insulated between each other along their length inside the armature airgap.

Abstract: A brushless permanent magnet motor has a rotor constructed of spaced ferromagnetic backirons and a circumferential array of alternating polarity magnetic poles that drive magnetic flux back and forth across an armature air gap between the backirons. A stator includes an air core armature in the air gap with three-phase windings. An inverter includes a pulse-modulated semiconductor H-bridge that switches and regulates power to the three-phase windings to drive the rotor. Harmonic losses in the motor caused by ripple currents generated by the higher pulse switching frequency in electronic variable speed drives, due to the inherently lower inductance of air core motors, are substantially reduced by adding serial inductance between the motor and drive. The H-bridge is serially electrically connected to the three-phase armature windings through three inductors that employ a low cost powder core.