Patent ID: 6876119

Claim:
A synchronous motor comprising: a stator including a stator iron core having two-pole windings wound therearound, said stator iron core having an inner cylindrical surface; a rotor including a rotor iron core rotatably accommodated facing the inner cylindrical surface of the stator iron core, said rotor including a plurality of conductor bars, positioned adjacent an outer periphery of the rotor iron core, and shortcircuit rings, positioned at axially opposite ends of the rotor iron core, said conductor bars and shortcircuit rings being molded together by aluminum die casting to form a starter cage conductor, said rotor having a plurality of magnet retaining slots defined therein on an inner side of the conductor bars; and permanent magnets embedded within the magnet retaining holes in the rotor and defining two magnetic poles of different polarities; said shortcircuit rings having an inner diameter positioned outwardly from associated magnet retaining holes, an inner diameter of the shortcircuit rings at a location adjacent one end of the magnetic poles being larger than an inner diameter at a location adjacent an intermediate point of the magnetic poles.