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US 2004/0169431 A1Published application
Permanent magnet synchronous motor
AssigneesMatsushita Electric Industrial Co., Ltd., Matsushita Refrigeration Company
InventorsKenji Sasaki, Teruo Tamura, Michihiro Yoshida, Toru Takimoto, Hideyuki Taniguchi, Hiroyuki Uesaka
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Abstract
A synchronous motor includes a stator, a rotor and permanent magnets. The rotor includes a rotor iron core and rotatable relative to the stator, a plurality of conductor bars accommodated within corresponding slots in the rotor iron core. The conductor bars have their opposite ends shortcircuited by respective shortcircuit rings to form a starter cage conductor. The rotor also has a plurality of magnet retaining slots defined therein at a location on an inner side of the conductor bars, in which hole permanent magnets are embedded.
Claims11
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.
2 more elements
A synchronous motor which comprises:
- a stator including a stator iron core having a winding wound therearound, said stator iron core having an inner cylindrical surface;
- a rotor including a rotor iron core that is rotatably connected to the inner cylindrical surface of the stator iron core, said rotor including a plurality of conductor bars accommodated within corresponding slots defined in an outer peripheral portion of the rotor iron core, said conductor bars having corresponding opposite ends shortcircuited by shortcircuit rings to form a starter cage conductor, said rotor having a plurality of magnet retaining holes positioned on an inner side of the conductor bars;
- and
- a plurality of permanent magnets embedded within the plurality of magnet retaining holes in the rotor, the plurality of magnets defining a north rotor magnetic pole and a south rotor magnetic pole, each of the rotor magnetic poles having a center point and opposing end points;
- wherein the slots in the outer peripheral portion of the rotor iron core are separated by slot intervals, slot intervals adjacent to the opposing end points of each of the rotor magnetic poles being smaller than a slot interval adjacent to the center point of each of the rotor magnetic poles.
2 more elements
A synchronous motor which comprises:
- a stator including a stator iron core having a winding wound therearound, said stator iron core having an inner cylindrical surface;
- a rotor including a rotor iron core that is rotatably connected to the inner cylindrical surface of the stator iron core, said rotor including a plurality of conductor bars accommodated within corresponding slots defined in an outer peripheral portion of the rotor iron core, said conductor bars having corresponding opposite ends shortcircuited by respective shortcircuit rings to form a starter cage conductor, said rotor having a plurality of magnet retaining holes positioned on an inner side of the conductor bars;
- and
- a plurality of permanent magnets embedded within the plurality of magnet retaining holes in the rotor, the plurality of permanent magnets defining a north rotor magnetic pole and a south rotor magnetic pole, each of the rotor magnetic poles having a center point and opposing end points;
- wherein each of the slots has a corresponding radial length, a radial length of a slot adjacent to the center point of each of the rotor magnetic poles being smaller than radial lengths of slots not adjacent to the center point of each of the rotor magnetic poles;
- and
- wherein a distance between a slot, positioned adjacent one end of each of the rotor magnetic poles, and the magnet retaining holes corresponding to the rotor magnetic poles is smaller than distances between slots, not positioned adjacent to one end of each the magnetic poles, and the corresponding magnet retaining holes.
4 more elements
Dependencies are inferred from the claim text.