Claims
- 1. 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. The synchronous motor as recited in claim 1, wherein the inner diameter of the shortcircuit rings on a side adjacent the permanent magnets lies outside the magnet retaining holes in the rotor iron core;
wherein an inner diameter of one of the shortcircuit rings adjacent one of the magnetic wherein an inner diameter of one of the shortcircuit rings adjacent one of the magnetic poles is larger than an inner diameter adjacent a point intermediate the magnetic poles; and wherein an inner diameter of at least one other of the shortcircuit rings lies inwardly of at least part of the magnet retaining holes; said synchronous motor further comprising an end plate comprising a non-magnetizable material positioned between the at least one other shortcircuit ring and the rotor iron core, covering the magnet retaining holes.
- 3. The synchronous motor as recited in claim 1, wherein the inner diameter of the shortcircuit rings on one side of the permanent magnets lies outside the magnet retaining holes in the rotor iron core;
wherein an inner diametric dimension of one of the shortcircuit rings adjacent one end of the magnetic poles is greater than an inner diametric dimension of the one of the shortcircuit rings adjacent the intermediate point of the magnetic poles; and wherein the inner diametric dimension of the at least one other of the shortcircuit rings lies inwardly of at least a part of the magnet retaining holes; said rotor iron core comprising a plurality of electromagnetic steel plates, one of the electromagnetic steel plates being adjacent the at least one other shortcircuit ring, not formed with the magnet retaining holes.
- 4. The synchronous motor as recited in claim 1, wherein the inner diameter of the shortcircuit rings on one side of the permanent magnets comprises a shape lying along the magnet retaining holes in the rotor iron core.
- 5. 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.
- 6. The synchronous motor as claimed in claim 5, wherein a slot interval circumferentially adjacent to the slot interval adjacent to the center point of at least one of the rotor magnetic poles in a direction of rotation of the rotor is greater than a slot interval circumferentially adjacent to the slot interval adjacent to the center point of the rotor magnetic pole in a direction opposite to the direction of rotation of the rotor.
- 7. The synchronous motor as claimed in claim 5, wherein the slots positioned adjacent to the center points of the rotor magnetic poles having shorter radial lengths than the slots positioned adjacent to the end points of the rotor magnetic poles.
- 8. The synchronous motor as claimed in claim 5, wherein an inner end of each slot is positioned a predetermined distance from the rotor magnetic poles, the slots positioned adjacent to the end points of the rotor magnetic poles having shorter distances to the rotor magnetic poles than the slots not positioned adjacent to the end points of the rotor magnetic poles.
- 9. The synchronous motor as claimed in claim 8, wherein the distances between the slots and the rotor magnetic poles progressively increase from the slots positioned adjacent to the end points of the rotor magnetic poles to the slots positioned adjacent to the respective center points of the rotor magnetic poles.
- 10. 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.
- 11. The asynchronous motor as claimed in claim 10, wherein distances between the slots and the magnet retaining holes progressively increase from the position adjacent one end of each of the rotor magnetic poles towards the position adjacent the respective center point of each of the rotor magnetic poles.
Priority Claims (6)
Number |
Date |
Country |
Kind |
11-203080 |
Jul 1999 |
JP |
|
11-203081 |
Jul 1999 |
JP |
|
11-257035 |
Sep 1999 |
JP |
|
11-272391 |
Sep 1999 |
JP |
|
2000-164285 |
Jun 2000 |
JP |
|
2000-164286 |
Jun 2000 |
JP |
|
Parent Case Info
[0001] This application is a divisional application of pending U.S. patent application No. 10/019,286, filed Jan. 2, 2002, which was the National Stage of International Application No. PCT/JP00/04693, filed Jul. 13, 2000, the disclosures of which are expressly incorporated herein by reference in their entireties. The International was published under PCT Article 21(2) in English.
Divisions (1)
|
Number |
Date |
Country |
Parent |
10019286 |
Jan 2002 |
US |
Child |
10792726 |
Mar 2004 |
US |