Magnetic field type of rotary electric apparatus
AssigneeKabushiki Kaisha Moric
InventorsHideaki Takahashi, Koichi Sano
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Abstract
Several embodiments of rotating electrical machines where cogging torque is reduced as well as the distortion of the back emf and improve torque characteristic with reduced torque ripples by dividing either the permanent magnets and/or the poles of the coil windings in axially separated portions that are circumferentially shifted relative to each other.
Claims8
A magnet field type rotary electric apparatus comprised of a rotor and a cooperating stator rotatable relative to each other about an axis, one of said rotor and said stator being comprised of a plurality of circumferentially spaced permanent magnets and the other of said rotor and said stator having a plurality of circumferentially spaced pole teeth surrounded by coil windings, at least one of said plurality of circumferentially spaced permanent magnetsand said plurality of circumferentially spaced pole teeth surrounded by coil windings being divided in an axial direction into plurality of stages (n) each of which is circumferentially displaced around said axis at angular intervals of Θ degrees relative to each other, said displacement angle of Θ is expressed as Θ=360°/(A×n), where A is the least common multiple of the number of pole teeth and the number of magnets.
Dependencies are inferred from the claim text.