| 摘要 |
PROBLEM TO BE SOLVED: To prevent certainly a rotating shaft from idling and to simplify mounting of a pointer. SOLUTION: A ring-shaped magnet 1 is formed of a rare earth magnet, has a magnetic anisotropy in a radial direction and has an axial hole 2 in which a rotating shaft 4 is inserted. In the ring-shaped magnet 1, the outer shape is formed in a substantially true circle shape. The shape of the axial hole 2 is formed in a variant shape different from the axial hole 2 and the axial hole shape is a symmetrical shape, and its symmetrical axial direction is set so as to substantially match with the direction of the magnetic anisotropy. The symmetrical shape is an axial symmetrical shape, and has only one or two symmetrical axes. As a concrete shape, for example, a rectangular, rhombic, elliptical, or oval shape or a shape having a notch for expanding a diameter. In a magnet rotor, the structure that a resin part 3 (and the rotating shaft 4) is arranged in the axial hole 2 of the ring-shaped magnet 1, and the resin part 3 (and the rotating shaft 4) and the ring-shaped magnet 1 are united, and rotated is formed. A pointer 5 is mounted at the rotating shaft 4. COPYRIGHT: (C)2006,JPO&NCIPI
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