| 摘要 |
PURPOSE:To improve power increase of rotary drive force without loss of stability of controlling a speed by integrally molding a multipolar permanent magnet for producing a drive force and a multipolar permanent magnet for controlling the speed. CONSTITUTION:Exciting coils 7 are wound on stator cores 6 disposed at multipoles radially on a concentrical disk to form a fixed stator 11, and a ring-shaped permanent magnet 12 alternately magnetized with N- and S-poles on the outer periphery of the stator cores 6 is formed on a rotary yoke 2. Then, a magnetic sensor 14 for sensing the polarity of the approaching magnet 12 to apply a signal for flowing a current selecting the timing and the direction to the coils 7 to generate a rotatable drive force is fixedly disposed near the magnet 12. Thus, the magnet 12 is integrally formed with a multipolar perma nent magnet portion 12a for producing a drive force and a multipolar permanent magnet portion 12b for controlling the speed. |
