US Patent 7843107 Dynamoelectric machine

A dynamoelectric machine including first and second permanent magnets held by first and second magnet seats on first and second yoke portions so as to face inner circumferential surfaces of tip end portions of first and second claw-shaped magnetic pole portions. The first and second permanent magnets are magnetically oriented in a reverse direction to orientation of a magnetic field that the field coil produces. The dynamoelectric machine enables permanent magnet holding reliability to be increased, induced voltage during no-load de-energization to be suppressed, and thermal demagnetization of magnets due to high-frequency magnetic fields that are induced by stator slots to be avoided.