Patent ID: 7772736

Claim:
A permanent magnet synchronous motor that has a stator with a stator winding and a rotor rotatably supported along an inner periphery of the stator with a fixed clearance therebetween and includes many slots provided in an axial direction along an outer periphery of a rotor iron core, which is part of the rotor, electrically conductive bars embedded in the slots, electrically conductive end rings, each of which connects one of the bars to an end surface in the axial direction, and permanent magnets embedded along an inner periphery of the bars, wherein: the permanent magnet synchronous motor has holes, magnetic substances, and bridges, each of which is formed between one of the permanent magnets and one of the holes, in a peripheral direction between the magnetic poles of the permanent magnets; a pitch angle θ of the magnetic substance in the peripheral direction is larger than a distance of the bridge in the peripheral direction, which is formed between the permanent magnet and the hole; and wherein a ratio θ/β of the pitch angle θ of the magnetic substance in the peripheral direction to the pitch angle β between magnetic poles in the peripheral direction is set within a range of 0.17 to 0.80.