Patent ID: 7372183

Claim:
A synchronous motor, comprising: a stator, including a stator iron core, comprising a winding wound therearound, the stator iron core including an inner cylindrical surface; a rotor, including a rotor iron core, rotatably connected to the inner cylindrical surface of the stator iron core, the rotor including a plurality of conductor bars, positioned adjacent an outer periphery of the rotor iron core, and a plurality of shortcircuit rings, positioned at axially opposite ends of the rotor iron core, the plurality of conductor bars and the plurality of shortcircuit rings being molded together by an aluminum die casting to form a starter cage conductor, the rotor iron core comprising a plurality of magnet retaining holes defined therein; and a plurality of permanent magnets embedded within the plurality of magnet retaining holes on an inner side of the plurality of conductor bars; the rotor iron core including a plurality of conductor bar holes defined therein in an axial direction thereof and positioned outwardly from the magnet retaining holes, the plurality of conductor bar holes being filled by the aluminum die casting substantially simultaneously with the starter cage conductor, the plurality of conductor bars protruding outwardly from an axial end of the rotor iron core to form projections for securing an end plate to the end of the rotor iron core, the end plate comprising a non-magnetizable material; wherein at least one electromagnetic steel plate at one axial end of the rotor iron core is not provided with a magnet retaining hole; wherein the at least one electromagnetic steel plate comprises at least one protrusion where the electromagnetic steel plate contacts at least one of the plurality of permanent magnets.