Patent ID: 8018111

Claim:
A hybrid excitation synchronous machine comprising: a stator core fixed to a motor frame and wound with a stator coil; a soft magnetic rotor core fixed to a rotation shaft and facing an inner peripheral surface of the stator core through a small gap; an even number of permanent magnets fixed to the rotor core in a predetermined pitch in a peripheral direction and magnetized in opposite magnetic polarities alternately for generating magnet magnetic flux that crosses the stator coil; an excitation coil for adjusting an amount of field magnetic flux crossing the stator coil; a stationary magnetic path member fixed to the motor frame and wound with the excitation coil; the rotor core including a soft magnetic inner cylindrical part fitted to the rotation shaft and even number of soft magnetic rotor magnetic pole parts located outside the inner cylindrical part in a radial direction; the permanent magnets including first permanent magnets fixed to even-numbered rotor magnetic pole parts that are located relative to an outer peripheral surface of the inner cylindrical part through a predetermined gap, for magnetizing the even-numbered rotor magnetic pole parts to first magnetic polarity; the permanent magnets including second permanent magnets fixed to odd-numbered rotor magnetic pole parts that are located in tight contact with the outer peripheral surface of the inner cylindrical part, for magnetizing the odd-numbered rotor magnetic pole parts to second magnetic polarity; and the stationary magnetic path member being located in proximity to an end surface of the rotor core to face the inner cylindrical part and the even-numbered rotor magnetic pole parts through predetermined gaps, wherein the excitation coil is arranged in magnetic series relation with the first permanent magnet and the second permanent magnet in a magnetic circuit that is formed by the first permanent magnet, the second permanent magnet, the stator core, the odd-numbered rotor magnetic pole part, the even-numbered rotor magnetic pole part, the stationary magnetic path member and the inner cylindrical part.