| 摘要 |
PURPOSE:To eliminate torque ripple, generated upon driving the title motor, and obtain a brushless motor having smooth torque, by a method wherein a signal output from a magnetic resistance element, provided on a stator yoke, is superposed on the driving voltage of the motor. CONSTITUTION:A multi-pole magnet 7 is fixed to a rotor yoke 4 and a magnetic resistance body pattern 20, on which magnetic resistance elements G1-G3 are formed, and Hall elements 10 are provided on the stator yoke 1 side of the rotor yoke 4. When respective poles of the multi-pole magnet 7 pass through the positions of the magnetic resistance elements G1-G3 in conduction with the rotation of the yoke 4, the values of resistance of the magnetic resistance elements are changed. The change of the value of resistance is converted into the change of voltage and the voltage is amplified and synthesized with motor driving voltage to control a motor. The number off crests of an output, obtained from the magnetic resistance body pattern 20, is three times the number of poles of the magnet 7 while the frequency of torque ripple generated in the motor is three times the number of poles of the magnet 7, therefore, the torque ripple may be eliminated. |
