Permanent magnet synchronous motor and compressor using the same
AssigneeHitachi Appliances, Inc.
InventorsSatoshi Kikuchi, Haruo Koharagi, Akeshi Takahashi, Tomio Yoshikawa, Baiying Huang
Life of this patent
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Abstract
A permanent magnet synchronous motor includes a rotor having cage windings and permanent magnets placed on an inner peripheral side of these cage winding bars, where the permanent magnets are placed and polarized so that a ratio θ/α between a circumferential pitch angle θ of magnetic flux distribution of the permanent magnets and a magnet pole pitch angle α is between 0.67 and 0.91.
Claims20
A permanent magnet synchronous motor including a rotor comprising:
- a large number of slots axially provided in proximity to a periphery of a rotor core, conductive bars embedded in the slots;
- conductive end rings for shorting the bars on axial end faces;
- and permanent magnets embedded in magnet insertion holes placed on inner peripheral side of the bars, wherein a ratio θ/α between a circumferential pitch angle θ of the permanent magnets and a magnet pole pitch angle α of the permanent magnets is in a range of greater than 0.67 to no greater than 0.91, and wherein the rotor comprises only two magnetic poles.
A permanent magnet synchronous motor including a rotor comprising:
- a large number of slots axially provided in proximity to a periphery of a rotor core, conductive bars embedded in the slots;
- conductive end rings for shorting the bars on axial end faces;
- and permanent magnets embedded in an inner peripheral side of the bars;
- wherein a ratio θ/α between a circumferential pitch angle θ of the permanent magnets and a magnet pole pitch angle α of the permanent magnets is in a range of greater than 0.61 to no greater than 0.91;
- and wherein the rotor comprises only two magnetic poles.
A rotor of a permanent magnet synchronous motor comprising:
- a large number of slots axially provided in proximity to a periphery of a rotor core, conductive bars embedded in the slots;
- conductive end rings for shorting the bars on axial end faces;
- and permanent magnets embedded in an inner peripheral side of the bars;
- wherein a ratio θ/α between a circumferential pitch angle θ of the permanent magnets and a magnet pole pitch angle α of the permanent magnets is in a range of greater than 0.67 to no greater than 0.91;
- and wherein the rotor comprises only two magnetic poles.
Dependencies are inferred from the claim text.