Patent ID: 6844652
Filing Date: 2005-01-18
Classification: H02K

Abstract:
1. A rotor structure of a line-start permanent magnet (LSPM) synchronous motor including an outer stator (or simply stator hereafter), an inner rotor (or simply rotor hereafter), and an air gap positioned between the stator and the rotor, wherein the inner loop of the stator has a plurality of stator tooth-part having tooth thickness w and a plurality of stator channel-part disposed in staggered manner and in annular shape while the rotor having a center O and a radius R of the circular arcs of the surface of the magnetic poles is divided into an inner loop and an outer loop, the motor comprises: a shaft positioned at the center of the rotor; four fan-shaped magnetic poles each having a 90° central angle and their arcs of the surface of the magnetic poles being defined as the “first eccentric circular arcs of the surface of the magnetic poles” with a center of the arc O four permanent magnets each of them disposed in each of the fan-shaped magnetic poles in the inner loop of the rotor; a plurality of conductive bar slots for forming squirrel cage winding, the conductive bar slots appearing in pear shape and being disposed in equal space, in annular shape, and in the outer loop of the rotor at each of the fan-shaped magnetic pole that make the space-part form salient tooth-part of the rotor, and the space-part between the fan-shaped magnetic pole is relatively small; and four recesses appearing in semi-circular shape with radius r and width w (equal to the stator's tooth thickness) and being provided at the mid-point of the first eccentric circular arcs of the surface of each of the fan-shaped magnetic poles and the locations of the recesses being aligned with the tooth-part of the rotor when the number of the conductive bar slots of the fan-shaped magnetic poles is an even number while the locations of the recesses being aligned with the conductive bar slots of the rotor when the number of the plurality of the conductive bar slots of the fan-shaped magnetic poles is an odd number; wherein except that the conductive bar slots at the location of the semi-circular recesses needs to adequately offset toward the center O