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US 8,618,711 B2Granted
Three-phase DC motor
AssigneeNabtesco Corporation
InventorYasuyuki Shirai
Life of this patent
Estimating the term…
Abstract
A three-phase DC motor includes a rotor 30 having poles 30a and a stator 28 having core units 32b arranged around the rotor 30. Three or more coils are wound around the core units 32b. An outer surface of the rotor 30 has alternating poles of N and S around the circumference of the rotor 30. The coils 35a, 35b, 35c, and 35d are placed only within a range defined by second virtual planes P2 specified respectively by rotating a first virtual plane P1 according to a predetermined angle in a rotor rotating direction and a direction opposite thereto. The first virtual plane P1 passes through the axial center of the rotor 30. The inner surface of the adjacent 3N (N=1, 2, 3, . . . ) number of core units 32b are delimited within a width of one pole on the outer surface of the rotor 30.
Claims7
A three-phase DC motor comprising:
- a rotor having an outer surface and magnets, said outer surface of said rotor being configured to have alternating poles of N and S around a circumference of said rotor;
- a stator including a plurality of core units that are arranged around said rotor and having an inner surface opposite to said outer surface of said rotor;
- and
- three or more coils wound around said core units, said three or more coils including a first coil through which a first phase current flows, a second coil through which a second phase current flows, and a third coil through which a third phase current flows, said first coil, said second coil, and said third coil are each wound around a bundle of adjacent core units, and said first coil, said second coil, and said third coil are offset in this order by ⅓ pole pitch in the rotor rotating direction, said coils being placed only within a range defined by second virtual planes, said second virtual planes being specified respectively by rotating a first virtual plane according to a predetermined angle in a rotor rotating direction and a direction opposite thereto, said first virtual plane being a plane passing through the axial center of said rotor,
- inner surfaces of an adjacent 3N (N=1, 2, 3, . . . ) number of core units of said a plurality of said core units being delimited within a width of one pole on said outer surface of said rotor.
2 more elements
A three-phase DC motor comprising:
- a rotor having an outer surface and magnets, said outer surface of said rotor being configured to have alternating poles of N and S around a circumference of said rotor;
- a stator including a plurality of core units that are arranged around said rotor and having an inner surface opposite to said outer surface of said rotor;
- and
- three or more coils wound around said core units, said coils being placed only within a range defined by second virtual planes, said second virtual planes being specified respectively by rotating a first virtual plane according to a predetermined angle in a rotor rotating direction and a direction opposite thereto, said first virtual plane being a plane passing through the axial center of said rotor,
- inner surfaces of an adjacent 3N (N=1, 2, 3, . . . ) number of core units of said a plurality of said core units being delimited within a width of one pole on said outer surface of said rotor, wherein
- an auxiliary coil is wound around at least core units placed at outermost ends on a side of said second virtual planes, out of said core units.
3 more elements
A three-phase DC motor comprising:
- a rotor having an outer surface and magnets, said outer surface of said rotor being configured to have alternating poles of N and S around a circumference of said rotor;
- a stator including a plurality of core units that are arranged around said rotor and having an inner surface opposite to said outer surface of said rotor;
- and
- three or more coils wound around said core units, said coils being placed only within a range defined by second virtual planes, said second virtual planes being specified respectively by rotating a first virtual plane according to a predetermined angle in a rotor rotating direction and a direction opposite thereto, said first virtual plane being a plane passing through the axial center of said rotor, inner surfaces of an adjacent 3N (N=1, 2, 3, . . . ) number of core units of said a plurality of said core units being delimited within a width of one pole on said outer surface of said rotor;
- and
- a casing in which said stator and said rotor are housed, wherein
- said casing has sides shorter in the direction perpendicular to said first virtual plane than sides in the direction parallel to said first virtual plane.
4 more elements
A three-phase DC motor comprising:
- a rotor having an outer surface and magnets, said outer surface of said rotor being configured to have alternating poles of N and S around a circumference of said rotor;
- a stator including a plurality of core units that are arranged around said rotor and having an inner surface opposite to said outer surface of said rotor;
- a first coil through which a first phase current flows;
- a second coil through which a second phase current flows;
- and
- a third coil through which a third phase current flows;
- said first coil, said second coil and said third coil being placed only within a range defined by second virtual planes, said second virtual planes being specified respectively by rotating a first virtual plane according to a predetermined angle in a rotor rotating direction and a direction opposite thereto, said first virtual plane being a plane passing through the axial center of said rotor,
- inner surfaces of an adjacent 3N (N=1, 2, 3, . . . ) number of core units of said a plurality of said core units being delimited within a width of one pole on said outer surface of said rotor,
- said first coil, said second coil, and said third coil are each wound around a bundle of adjacent core units, and
- said first coil, said second coil, and said third coil are offset in this order by ⅓pole pitch in the rotor rotating direction.
7 more elements
Dependencies are inferred from the claim text.