| 摘要 |
PURPOSE:To reduce a torque ripple by making such a form that the width of a non-polarized pole increases from the inner circumferential side toward the outer circumferential side thereof. CONSTITUTION:A motor is so constituted that a permanent magnet 1 is fixed to a shaft 5 through a yoke 3 and a boss 4 to form a permanent magnet rotor 10. A stator 11 is constituted of a driving coil 9 together with a bracket 7 through a core 8. The permanent magnet rotor 10 is rotatably held by the stator 11 through a bearing 6. At that time, the permanent magnet 1 has four poles, three coil, each pole of the permanent magnet 1 has two non-polarized poles 2, and the poles 2 are arranged symmetrically to the pole center of the permanent magnet 1. The inner side width (h1) and the outer side width (h2) of the non-polarized pole are so formed that the (h2) is larger than the (h1). Accordingly, a torque ripple in operation can be reduced while maintaining desired magnet characteristic of the permanent magnet 1. |
