Rotor, electric motor, air blower, air conditioner, and method for fabricating rotor
AssigneeMitsubishi Electric Corporation
InventorsTakanori WATANABE, Hiroki ASO
Life of this patent
Estimating the term…
Abstract
A rotor includes at least one first permanent magnet and at least one second permanent magnet. The at least one first permanent magnet forms part of an outer peripheral surface of the rotor and is magnetized to have polar anisotropy. The at least one second permanent magnet is adjacent to the at least one first permanent magnet in a circumferential direction of the rotor and has lower magnetic force than magnetic force of the at least one first permanent magnet.
Claims20
A rotor having 2n (n is a natural number) magnetic poles, comprising;
- at least one first permanent magnet forming part of an outer peripheral surface of the rotor and magnetized to have polar anisotropy;
- and
- at least one second permanent magnet that is a different type from the at least one first permanent magnet, is adjacent to the at least one first permanent magnet in a circumferential direction of the rotor, has lower magnetic force than magnetic force of the at least one first permanent magnet, and is magnetized to have polar anisotropy, and
- the at least one second permanent magnet is a single integral ring-shaped magnet.
A rotor having 2n (n is a natural number) magnetic poles and including a plurality of layered magnets composed of two to m (m is a natural number and a divisor for n) layers that are stacked in an axial direction, wherein
- each layered magnet of the plurality of layered magnets includes
- at least one first permanent magnet forming part of an outer peripheral surface of the rotor and magnetized to have polar anisotropy, and
- at least one second permanent magnet that is a different type from the at least one first permanent magnet, is adjacent to the at least one first permanent magnet in a circumferential direction of the rotor, has lower magnetic force than magnetic force of the at least one first permanent magnet, and is magnetized to have polar anisotropy, and
- in each first permanent magnet of the plurality of layered magnets, supposing one cycle is an angle formed by adjacent north poles in a plane orthogonal to the axial direction of the rotor, positions of north poles of two first permanent magnets adjacent to each other in the axial direction are shifted from each other by n/m cycles in the circumferential direction, and
- the at least one second permanent magnet is a single integral ring-shaped magnet.
A method for fabricating a rotor including a first permanent magnet and a second permanent magnet, the second permanent magnet being adjacent to the first permanent magnet in a circumferential direction and having lower magnetic force than magnetic force of the first permanent magnet, the method comprising:
- generating a magnetic field having polar anisotropy inside a mold for the second permanent magnet, by using a magnet for magnetization;
- molding the second permanent magnet magnetized to have polar anisotropy into a single integral ring-shaped magnet, by injection molding;
- generating a magnetic field having polar anisotropy inside a mold for the first permanent magnet, by using a magnet for magnetization;
- and
- molding the first permanent magnet by injection molding on an outer peripheral surface of the second permanent magnet so that the first permanent magnet forms part of an outer peripheral surface of the rotor, in a state where the second permanent magnet is disposed inside the mold for the first permanent magnet.
Dependencies are inferred from the claim text.