Permanent magnet rotator and motor using the same
AssigneePanasonic Corporation
InventorsFumitoshi Yamashita, Hiroshi Murakami, Yukihiro Okada, Kiyomi Kawamura
Life of this patent
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Abstract
A motor generally has a contradictory relation between decrease of cogging torque and increase of torque density. To overcome this problem, continuous direction control is provided for anisotropy with modification of magnetic poles so that the average absolute value of differences between Mθ and 90×sin [φ{2π/(360/p)}] is set to be 3° or less, where Mθ is a direction of anisotropy with respect to a radial tangent line of a magnetic pole plane, φ is a mechanical angle, and p is the number of pole pairs.
Claims18
A permanent magnet rotator which is adapted to provide continuous direction control for anisotropy with modification of magnetic poles so that the average absolute value of differences between Mθ and 90×sin[φ{2π/(360/p)}] is set to be 3° or less, where Mθ is an angle of magnetization vector (M) with respect to a radial tangent line of a magnetic pole plane, φ is a mechanical angle, and p is the number of pole pairs.
Dependencies are inferred from the claim text.