Patent ID: 7777382
Filing Date: 2010-08-17
Classification: H02K

Abstract:
1. A rotor comprising; a rotor core having a rotor surface; a plurality of permanent magnets embedded in the rotor core with each of the permanent magnets defining a pole of the rotor, each pole of the rotor having a pole center and a peripheral edge section, with the peripheral edge section of each of the permanent magnets being located in a vicinity between the poles and a vicinity of the rotor surface; and a plurality of non-magnetic layers being located in a vicinity of the rotor surface at a pole center side position with respect to the peripheral edge section of each of the permanent magnets, the peripheral edge sections and the non-magnetic layers being positioned to cancel 5-th order harmonics or 7-th order harmonics of an induction voltage, the poles being disposed at every approximately constant interval, varying in a constant angle, the peripheral edge section of each of the permanent magnets and the non-magnetic layers being independent from one another, and the rotor core being interposed between them, and an angle θ where a pole pair number is Pn.