| 摘要 |
PURPOSE:To obtain an extremely small-sized, high-resolution rotation detecting device by providing a magnetic sensor opposite a magnetic recording part which is subjected to multipole magnetization at the periphery of a rotating shaft provided rotatably by bearings. CONSTITUTION:The magnetic recording part 6 which is subjected to multipole magnetization so that their polarities are alternately inverted in the rotating direction of the rotating shaft 1 provided rotatably to a holder 2 by the bearings 3 and 4 and fixed to a fixed shaft 5 is arranged on the peripheral surface of the rotating shaft 1 between the bearings 3 and 4. On the other hand a magnetic sensor 7 is fixed to a magnetic sensor fitting part 8 opposite the magnetic recording part 6 and this sensor 7 is used to transduce the periodic variation of a magnetic field produced by the rotation of the rotating shaft 1 into an electric signal. With this assembly, vibrations of the magnetic recording part 6 to the magnetic sensor 7 due to the rotation of the rotating shaft 1 are extremely small, so the gap length between the magnetic sensor 7 and magnetic recording part 6 and the recording wavelength of the recording part 6 are reducible, so that high resolution is obtained. |
