| 摘要 |
PURPOSE:To eliminate the generation of counter electromotive force and irregular rotation, by performing multipolar magnetization to provide a sinusoidal distribution of magnetic flux density around a permanent magnet and supplying a sinusoidal exciting current to stator windings in accordance with the action of magnetism sensors opposing each other. CONSTITUTION:The polar magnetization of a rotor magnet 4, which serves also as a magnetic pole position detecting magnet, is performed to provide such a sinusoidal distribution of magnetic flux density that the flux density has its maximum value in the center of each pole and is zero at the coupled parts of the pole. Magnetism sensors 7, 7', 7'' are placed at an angular spacing of 120 deg. in the face of the magnet 4 and connected to stator windings 6, 6', 6'' through linear DC amplifiers 8, 8', 8'' so that a sinusoidal exciting current flows through each stator winding. Because switching is not effected, no counter electromotive force is caused. The exciting current is smoothly varied to prevent irregular rotation. |
