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US 7,612,480 B2Granted
Interior permanent magnet motor
AssigneeNidec Corporation
InventorsYoshio Fujii, Hideaki Suzuki
Life of this patent
Estimating the term…
Abstract
A rotor portion of a motor includes a rotor core and a plurality of field magnets arranged in a circumferential direction at the rotor core. The rotor core includes at a flux barrier portion thereof arranged between a pair of field magnets of opposite magnetic polarities arranged next to one another a flux barrier hole. The flux barrier hole is independent of a magnet retaining hole in which the field magnet is retained. The magnet retaining hole includes a concave portion extending from a side thereof nearest to the flux barrier hole toward the corresponding flux barrier hole.
Claims20
A motor comprising:
- a rotor portion rotating about a central axis and including:
- a shaft arranged concentrically with the central axis;
- a rotor core having a substantially cylindrical shape attached to the shaft;
- and
- a plurality of field magnets arranged at an outer circumferential surface of the rotor core facing the central axis, and each of the plurality of field magnets extending in a direction that is substantially parallel to the central axis;
- wherein
- the rotor core includes:
- a plurality of magnet retaining holes accommodating therein the plurality of field magnets;
- and
- a plurality of flux barrier holes arranged in the direction that is substantially parallel to the central axis at a space between a corresponding pair of the plurality of field magnets, one magnet in the corresponding pair of the plurality of field magnets having a magnetic polarity different from another magnet in the corresponding pair of the plurality of field magnets;
- wherein
- each of the plurality of flux barrier holes is independent of a corresponding pair of the plurality of magnet retaining holes;
- each of the plurality of magnet retaining holes includes a concave portion extending toward a corresponding flux barrier hole;
- and
- each of the plurality of magnet retaining holes includes at a side thereof facing the corresponding flux barrier hole a pair of side portions spaced apart from one another, and each of the plurality of magnet retaining holes includes the concave portion at a portion radially between the pair of side portions.
12 more elements
A motor comprising:
- a rotor portion rotating about a central axis and including:
- a shaft arranged concentrically with the central axis;
- a rotor core having a substantially cylindrical shape attached to the shaft;
- and
- a plurality of field magnets arranged at an outer circumferential surface of the rotor core facing the central axis, and each of the plurality of field magnets extending in a direction that is substantially parallel to the central axis;
- wherein
- the rotor core includes:
- a plurality of magnet retaining holes accommodating therein the plurality of field magnets;
- and
- a plurality of flux barrier holes arranged in the direction that is substantially parallel to the central axis at a space between a corresponding pair of the plurality of field magnets, each corresponding pair of the plurality of field magnets having a magnetic polarity different from each adjacent pair of the plurality of field magnets;
- wherein
- each of the plurality of flux barrier holes is independent of a corresponding pair of the plurality of magnet retaining holes;
- each of the plurality of magnet retaining holes includes a concave portion extending toward a corresponding flux barrier hole;
- and
- each of the plurality of magnet retaining holes includes a gap clearance arranged to provide a space between the field magnet accommodated therein, at a side thereof circumferentially opposite from the concave portion.
12 more elements
Dependencies are inferred from the claim text.