| 摘要 |
PURPOSE:To make it possible to effect an accurate speed detection with a frequency generator coupled to a motor, by derecting the magnetic flux leaked from the motor by means of a correction coil and compensating for the change of the generator output using the output of the correction coil. CONSTITUTION:A rotor yoke 4 and a motor magnet 5 are fixed to a rotor shaft 2. A motor-driving coil 6 secured to a frame 1 produces a magnetic force by which the rotor is driven. A frequency generator FG is attached to the rotor yoke 4 through the medium of a non-magnetic spacer 15. An FG magnet 9 and an FG rotor yoke 10 are secured to the rotor 8 of the frequency generator FG. An FG coil 12, which is surrounded by an FG stator yoke 11 and an FG stator 13, detects the rotation signal. A correction coil 14, which is positioned outside the magnetic circuit (8-9-10-11-13), detects only the magnetic flux leaked to the outside of the driving coil 6. The output from the frequency generator FG is corrected by means of the output signal from the correction coil 14. |
