Patent ID: 6140729
Filing Date: 2000-10-31
Classification: H02K,H02P

Abstract:
An electrical machine comprising a rotor (7) without windings, a stator (2) having poles and armature windings (11) wound with a pitch corresponding to a plurality of pole pitches, the stator (2) also including field magnet means (10) for generating a magnetomotive force in a direction extending transversely of the magnetomotive force generated by the armature windings (11), and circuit means (40-47, 50-53, 57-62A) connected to the armature windings (11), characterised in that the armature windings comprise at least two coils (24, 25) which are closely coupled magnetically with a coupling which is substantially independent of rotor position, the coils (24, 25) having active portions at substantially the same angular orientations with respect to the stator and the coils (24, 25) being wound so that the currents in the coils (24, 25) vary in synchronism with rotation of the rotor (7) in such a manner that periods in which a magnetomotive force in one direction is generated by current flow in one of the coils alternate with periods in which a magnetomotive force in the opposite direction is generated by current flow in another of the coils.