Patent attributes
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.