| 摘要 |
PROBLEM TO BE SOLVED: To provide a field magneton that reduces the harmonic component of flux density. SOLUTION: Permanent magnets 20 are pinched by magnetic plates 1, 3 in the direction parallel to the axis of rotation P. The magnetic plates 1 have magnetic materials 10, 12 and non-magnetic materials 11, 13. The magnetic material 10 is in contact with one permanent magnet in the direction of the axis of rotation including pole center. The magnetic material 10, the non-magnetic material 11, the magnetic material 12, the non-magnetic material 13 are arranged in this order in the circumferential direction centering on the axis of rotation regarding the pole center as a starting point. The permanent magnet 20 is provided exceeding the non-magnetic material 11 in the circumferential direction. An angleθ1 made by the end portion 131 of the non-magnetic material 13 at the pole center side from interpole is 0<θ1<180/(i×Pn), when the number of pairs of poles is represented by Pn and when three or more odd number is set to i. An angleθ2 made by the end portion 111 of the non-magnetic material 11 at the pole center side from interpole is 180/(i×Pn)≤θ2≤180×2/(i×Pn). COPYRIGHT: (C)2009,JPO&INPIT
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