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EP-4164093-B1 - ELECTRIC MOTOR, COMPRESSOR, BLOWER, AND FREEZER DEVICE

EP4164093B1EP 4164093 B1EP4164093 B1EP 4164093B1EP-4164093-B1

Inventors

  • SAKURAGI, Takuya
  • YASUDA, YOSHIKI
  • MIWA, Daiki
  • YAMAGIWA, AKIO
  • HIBINO, HIROSHI

Dates

Publication Date
20260513
Application Date
20210608

Claims (15)

  1. An electric motor (1) comprising: a stator (10, 30); a rotor (20, 40, 60) facing the stator (10, 30) in a first direction and configured to be rotatable in a second direction that is orthogonal to the first direction; and a short-circuit reduction part (25, 26, 28, 44, 47, 48, 64), wherein the rotor (20, 40, 60) includes: a first magnet (22, 42, 62) having a first magnetic pole on a surface facing the stator (10, 30); a second magnet (23, 24, 27, 43, 46, 63) arranged adjacent to the first magnet (22, 42, 62) and having a second magnetic pole and a third magnetic pole that is different in polarity from the second magnetic pole, and configured to increase a magnetic flux of the first magnetic pole, and wherein the second magnet (23, 24, 27, 43, 46, 63) is arranged adjacent to the first magnet (22, 42, 62) in a third direction that is orthogonal to the first direction, and the short-circuit reduction part (25, 26, 28, 44, 47, 48, 64) is provided at a portion around the second magnet (23, 24, 27, 43, 46, 63) facing the second magnet (23, 24, 27, 43, 46, 63) in parallel with a virtual line connecting the second magnetic pole and the third magnetic pole, to reduce a short-circuit of a magnetic flux between the second magnetic pole and the third magnetic pole, characterized in that the short-circuit reduction part (25, 26, 28, 44, 47, 48, 64) is provided with a non-magnetic body.
  2. The electric motor (1) according to claim 1, wherein the third direction is orthogonal to the second direction.
  3. The electric motor (1) according to claim 1 or 2, wherein the rotor (20, 40, 60) and the stator (10, 30) are arranged facing each other in an axial direction, the first magnet (22, 42, 62) is arranged such that a plurality of the first magnetic poles are arranged side by side in a circumferential direction centering around a rotary shaft (50), and the second magnet (23, 24, 27, 43, 46, 63) is arranged such that the second magnetic pole or the third magnetic pole is adjacent to each of the plurality of the first magnetic poles in a radial direction.
  4. The electric motor (1) according to claim 1 or 2, wherein the rotor (20, 40, 60) and the stator (10, 30) are arranged facing each other in a radial direction, the first magnet (22, 42, 62) is arranged such that a plurality of the first magnetic poles are arranged side by side in a circumferential direction centering around a rotary shaft (50), and the second magnet (23, 24, 27, 43, 46, 63) is arranged such that the second magnetic pole or the third magnetic pole is adjacent to each of the plurality of the first magnetic poles in an axial direction.
  5. The electric motor (1) according to claim 1, wherein the third direction is the same as the second direction.
  6. The electric motor (1) according to claim 1 or 5, wherein the rotor (20, 40, 60) and the stator (10, 30) are arranged facing each other in an axial direction, the first magnet (22, 42, 62) is arranged such that a plurality of the first magnetic poles are arranged side by side in a circumferential direction centering around a rotary shaft (50), and the second magnet (23, 24, 27, 43, 46, 63) is arranged such that the second magnetic pole or the third magnetic pole is adjacent to each of the plurality of the first magnetic poles in the circumferential direction.
  7. The electric motor (1) according to claim 1 or 5, wherein the rotor (20, 40, 60) and the stator (10, 30) are arranged facing each other in a radial direction, the first magnet (22, 42, 62) is arranged such that a plurality of the first magnetic poles are arranged side by side in a circumferential direction centering around a rotary shaft (50), and the second magnet (23, 24, 27, 43, 46, 63) is arranged such that the second magnetic pole or the third magnetic pole is adjacent to an end portion in a direction orthogonal to a main magnetic flux of each of the plurality of the first magnetic poles as viewed in an axial direction.
  8. The electric motor (1) according to any one of claims 1 to 7, wherein the first magnet (22, 42, 62) has a fourth magnetic pole on a surface different from the surface having the first magnetic pole, the rotor (20, 40, 60) includes a first member (211, 411, 611) forming a magnetic path between a plurality of the first magnets (22, 42, 62) and a plurality of the fourth magnetic poles, and the short-circuit reduction part (25, 26, 28, 44, 47, 48, 64) has a magnetic resistance that is higher than that of the first member (211, 411, 611).
  9. The electric motor (1) according to any one of claims 1 to 8, wherein the second magnet (23, 24, 27, 43, 46, 63) is magnetized in a direction orthogonal to a magnetization direction of the first magnet (22, 42, 62).
  10. The electric motor (1) according to any one of claims 1 to 8, wherein the second magnet (23, 24, 27, 43, 46, 63) is magnetized in a direction intersecting a magnetization direction of the first magnet (22, 42, 62) by an angle greater than zero degrees and less than 90 degrees.
  11. The electric motor (1) according to any one of claims 1 to 10, wherein at least one of the first magnet (22, 42, 62) or the second magnet (23, 24, 27, 43, 46, 63) is magnetized in a polar anisotropic magnetization orientation.
  12. The electric motor (1) according to any one of claims 1 to 11, wherein the first magnet (22, 42, 62) and the second magnet (23, 24, 27, 43, 46, 63) are integrally configured.
  13. A compressor (112) in which the electric motor (1) according to any one of claims 1 to 12 is installed.
  14. A blower (115, 123) in which the electric motor (1) according to any one of claims 1 to 12 is installed.
  15. A refrigerator (10, 300) comprising: a compressor (112); and a blower (115, 123), wherein in at least one of the compressor (112) or the blower (115, 123), the electric motor (1) according to any one of claims 1 to 12 is installed.

Description

[Technical Field] The present disclosure relates to electric motors, compressors, blowers, and refrigerators. [Background Art] For example, with respect to a main magnet having a magnetic pole on the surface facing the stator, there is known a technology to increase the output of the electric motor by arranging auxiliary magnets in a Halbach array so as to increase the magnetic flux of the magnetic pole facing the stator of the main magnet (see JP 2019 161760 A). US 2005 0179337 A1 describes an axial gap electric rotary machine in which a rotor and a stator face each other and are axially spaced across the axial gap. [Summary of Invention] [Technical Problem] However, in JP 2019 161760 A, auxiliary magnets are provided in the rotor core. Therefore, a magnetic flux that short-circuits between the magnetic poles of the auxiliary magnets is generated through the rotor core, and as a result, the magnetic flux of the magnetic poles facing the stator of the main magnet may not be sufficiently increased. The purpose of the present disclosure is to provide a technique by which the magnetic flux of the magnetic pole facing the stator of the magnet can be further increased in a rotor. The present invention is defined by the appended set of claims. [Solution to Problem] One embodiment of the present disclosure provides an electric motor including: a stator;a rotor facing the stator in a first direction and configured to be rotatable in a circumferential direction that is orthogonal to the first direction; anda short-circuit reduction part, whereinthe rotor includes: a first magnet having a first magnetic pole on a surface facing the stator;a second magnet arranged adjacent to the first magnet and having a second magnetic pole and a third magnetic pole that is different in polarity from the second magnetic pole, and configured to increase a magnetic flux of the first magnetic pole, and whereinthe second magnet is arranged adjacent to the first magnet in a third direction that is orthogonal to the first direction, andthe short-circuit reduction part is provided at a portion around the second magnet facing the second magnet in parallel with a virtual line connecting the second magnetic pole and the third magnetic pole, to reduce a short-circuit of a magnetic flux between the second magnetic pole and the third magnetic pole, wherein the short-circuit reduction part is provided with a non-magnetic body. According to the present embodiment, the magnetic flux that short-circuits between the magnetic poles of the second magnet is less likely to occur through the portion surrounding the second magnet that faces the second magnet in parallel with the virtual line connecting the magnetic poles inside the second magnet. Therefore, the magnetic flux of the magnetic pole facing the stator of the first magnet can be further increased. Further, in the above embodiment, the third direction is orthogonal to the second direction. Further, in the above embodiment, the rotor and the stator are arranged facing each other in an axial direction,the first magnet is arranged such that a plurality of the first magnetic poles are arranged side by side in a circumferential direction centering around a rotary shaft, andthe second magnet is arranged such that the second magnetic pole or the third magnetic pole is adjacent to each of the plurality of the first magnetic poles in a radial direction. Further, in the above embodiment, the rotor and the stator are arranged facing each other in a radial direction,the first magnet is arranged such that a plurality of the first magnetic poles are arranged side by side in a circumferential direction centering around a rotary shaft, andthe second magnet is arranged such that the second magnetic pole or the third magnetic pole is adjacent to each of the plurality of the first magnetic poles in an axial direction. Further, in the above embodiment, the third direction is the same as the second direction. Further, in the above embodiment, the rotor and the stator are arranged facing each other in an axial direction,the first magnet is arranged such that a plurality of the first magnetic poles are arranged side by side in a circumferential direction centering around a rotary shaft, andthe second magnet is arranged such that the second magnetic pole or the third magnetic pole is adjacent to each of the plurality of the first magnetic poles in the circumferential direction. Further, in the above embodiment, the rotor and the stator are arranged facing each other in a radial direction,the first magnet is arranged such that a plurality of the first magnetic poles are arranged side by side in a circumferential direction centering around a rotary shaft, andthe second magnet is arranged such that the second magnetic pole or the third magnetic pole is adjacent to an end portion in a direction orthogonal to a main magnetic flux of each of the plurality of the first magnetic poles as viewed in an axial direction. Further, i