| 摘要 |
PURPOSE:To detect the position of a pole in high reliability by arranging ferromagnetic units at the outside of a rotational shaft, and arranging a sensor for detecting the position of the pole between the ferromagnetic units and a rotor magnet. CONSTITUTION:A ferromagnetic unit 12 is provided at the outside of a rotational shaft of a rotor 2 engaged at the radial inside of a rotor magnet 4, i.e., a rotational shaft 1. The unit 12 rotates integrally with the magnet 4. A sensor 9 is arranged between the magnet 4 and the unit 12, and the position of the pole of the magnet 4 is detected by the sensor 9. Since the magnetic flux passes the unit 12, it increases. |
