| 摘要 |
PURPOSE:To eliminate a torque ripple by restricting the rotating angle of a rotor coil block 360 deg. or less, and maintaining a magnetic flux applied to the block constant. CONSTITUTION:A rotational shaft 1 is rotatably supported by the first and second bearings 2, 3, the bearing 2 is disposed on an upper tab 4, and the bearing 3 is disposed on a lower tab 5. A rotor coil block 6 is secured through a rotor ring 13 to the shaft 1, and a center yoke 7 is disposed in a hollow portion, an inner magnet block 8 secured to the inner yoke 9 is disposed at the inner peripheral side, and an outer magnet block 10 secured to the casing yoke 11 is disposed on the outer peripheral side. A slit plate 14 is secured to the ring 13, and a light emitting diode 16 opposed thereto is secured to the first board 15, and a phototransistor 18 is secured to the second board 17. Further, the rotary angle of the block 6 is restricted to the 360 deg. or less, and the torque constant can be maintained constant. |
