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EP-4737749-A1 - THRUST MAGNETIC BEARING AND REFRIGERATION DEVICE

EP4737749A1EP 4737749 A1EP4737749 A1EP 4737749A1EP-4737749-A1

Abstract

With respect to a thrust magnetic bearing, a technology for appropriately holding an assembly of an insulating member and a coil in a groove portion of a core is provided. A thrust magnetic bearing 500 according to an embodiment of the present disclosure is a thrust magnetic bearing 500 for supporting a thrust load on a rotating shaft 250 of a compressor 10, the thrust magnetic bearing including an annular core 520 provided with a groove portion 521 having an annular opening 521A at an end face in an axial direction; and a coil assembly 530 including an annular insulating member 540 and a coil 550 wound around the insulating member 540, the coil assembly 530 being accommodated in the groove portion 521, wherein an outer diameter D2 of the opening 521A is shorter than an outer diameter d2 of the coil assembly 530 in a part of or an entirety of a circumferential direction, or an inner diameter D1 of the opening 521A is longer than an inner diameter d1 of the coil assembly 530 in a part of or an entirety of the circumferential direction.

Inventors

  • The designation of the inventor has not yet been filed

Assignees

  • Daikin Industries, Ltd.

Dates

Publication Date
20260506
Application Date
20250603

Claims (8)

  1. A thrust magnetic bearing for supporting a thrust load on a rotating shaft (250) of a compressor (10), the thrust magnetic bearing comprising: an annular core (520) provided with a groove portion (521) having an annular opening (521A) at an end face in an axial direction; and a coil assembly (530) including an annular insulating member (540) and a coil (550) wound around the insulating member (540), the coil assembly (530) being accommodated in the groove portion (521), wherein an outer diameter (D2) of the opening (521A) is shorter than an outer diameter (d2) of the coil assembly (530) in a part of or an entirety of a circumferential direction, or an inner diameter (D1) of the opening (521A) is longer than an inner diameter (d1) of the coil assembly (530) in a part of or an entirety of the circumferential direction.
  2. The thrust magnetic bearing according to claim 1, wherein the groove portion (521) includes a housing portion (521B) in which the coil assembly (530) is accommodated, the outer diameter (D2) of the opening (521A) is shorter than an outer diameter (D3) of the housing portion (521B) in a part of or an entirety of the circumferential direction, or the inner diameter of the opening (521A) is longer than an inner diameter (D4) of the housing portion (521B) in a part of or an entirety of the circumferential direction, and a dimension (W1) in an axial direction of the housing portion (521B) is greater than or equal to a dimension (w1) in the axial direction of the coil assembly (530) in an entirety of the circumferential direction.
  3. The thrust magnetic bearing according to claim 1 or 2, wherein the outer diameter (D2) of the opening (521A) is shorter than the outer diameter (d2) of the coil assembly (530) in a part of or an entirety of the circumferential direction, and a difference (δ) between the outer diameter (D2) of the opening (521A) and the outer diameter (d2) of the coil assembly (530) is less than or equal to 1% of the outer diameter (d2) of the coil assembly (530), or the inner diameter (D1) of the opening (521A) is longer than the inner diameter (d1) of the coil assembly (530) in a part of or an entirety of the circumferential direction, and a difference (δ) between the inner diameter (D1) of the opening (521A) and the inner diameter (d1) of the coil assembly (530) is less than or equal to 1% of the inner diameter (d1) of the coil assembly (530).
  4. The thrust magnetic bearing according to any one of claims 1 to 3, wherein in a state before the coil assembly (530) is accommodated in the groove portion (521), the outer diameter (D2) of the opening (521A) is greater than or equal to the outer diameter (d2) of the coil assembly (530) in an entirety of the circumferential direction, and the inner diameter (D1) of the opening (521A) is less than or equal to the inner diameter (d1) of the coil assembly (530) in an entirety of the circumferential direction.
  5. The thrust magnetic bearing according to claim 4, wherein the core (520) includes a first core portion (520C) and a second core portion (520D) attached to the first core portion (520C), and in a state where the second core portion (520D) is attached to the first core portion (520C), the outer diameter (D2) of the opening (521A) is shorter than the outer diameter (d2) of the coil assembly (530) in a part of or an entirety of the circumferential direction, or the inner diameter (D1) of the opening (521A) is longer than the inner diameter (d1) of the coil assembly (530) in a part of or an entirety of the circumferential direction.
  6. The thrust magnetic bearing according to claim 4, wherein the core (520) includes a third core portion (520E) and a fourth core portion (520F) integrally formed with the third core portion (520E), and in a state before the coil assembly (530) is accommodated in the groove portion (521), the outer diameter (D2) of the opening (521A) is greater than or equal to the outer diameter (d2) of the coil assembly (530) in an entirety of the circumferential direction, and the outer diameter (D2) of the opening (521A) becomes shorter than the outer diameter (d2) of the coil assembly (530) in a part or an entirety of the circumferential direction due to deformation of the fourth core portion (520F) by an external force after the coil assembly (530) is accommodated in the groove portion (521), or in a state before the coil assembly (530) is accommodated in the groove portion (521), the inner diameter (D1) of the opening (521A) is less than or equal to the inner diameter (d1) of the coil assembly (530), and the inner diameter (D1) of the opening (521A) becomes longer than the inner diameter (d1) of the coil assembly (530) in a part or an entirety of the circumferential direction due to deformation of the fourth core portion (520F) by an external force after the coil assembly (530) is accommodated in the groove portion (521).
  7. The thrust magnetic bearing according to claim 4, wherein in a state before the coil assembly (530) is accommodated in the groove portion (521), the outer diameter (d2) of the coil assembly (530) is less than or equal to the outer diameter (D2) of the opening (521A) in an entirety of the circumferential direction, and the outer diameter (d2) of the coil assembly (530) becomes longer than the outer diameter (D2) of the opening (521A) in a part or an entirety of the circumferential direction due to deformation of the insulating member (540) by an external force after the coil assembly (530) is accommodated in the groove portion (521), or in a state before the coil assembly (530) is accommodated in the groove portion (521), the inner diameter (d1) of the coil assembly (530) is greater than or equal to the inner diameter (D1) of the opening (521A) in an entirety of the circumferential direction, and the inner diameter (d1) of the coil assembly (530) becomes shorter than the inner diameter (D1) of the opening (521A) in a part or an entirety of the circumferential direction due to deformation of the insulating member (540) by an external force after the coil assembly (530) is accommodated in the groove portion (521).
  8. A refrigerating apparatus comprising: the thrust magnetic bearing (500) according to any one of claims 1 to 7.

Description

Technical Field The present disclosure relates to a thrust magnetic bearing, etc. Background Art Conventionally, with respect to a thrust magnetic bearing, a technology for arranging and holding an assembly in an annular groove portion of a core is known, the assembly including an annular insulating member such as a bobbin and a coil having a conductor wound around the insulating member (see, for example, Patent Document 1). Citation List Patent Document [Patent Document 1] Japanese Examined Utility Model (Registration) Application Publication No. S61-24735 Summary of Invention Technical Problem However, there is room for improvement in technology for holding an assembly of an insulating member and a coil in an annular groove portion of a core. It is an object of the present disclosure to provide a technology for appropriately holding an assembly of an insulating member and a coil in a groove portion of a core, with respect to a thrust magnetic bearing. Solution to Problem According to a first aspect of the present disclosure, there is provided a thrust magnetic bearing for supporting a thrust load on a rotating shaft (250) of a compressor (10), the thrust magnetic bearing including: an annular core (520) provided with a groove portion (521) having an annular opening (521A) at an end face in an axial direction; anda coil assembly (530) including an annular insulating member (540) and a coil (550) wound around the insulating member (540), the coil assembly (530) being accommodated in the groove portion (521), whereinan outer diameter (D2) of the opening (521A) is shorter than an outer diameter (d2) of the coil assembly (530) in a part of or an entirety of a circumferential direction, or an inner diameter (D1) of the opening (521A) is longer than an inner diameter (d1) of the coil assembly (530) in a part of or an entirety of the circumferential direction. In the present embodiment, the thrust magnetic bearing can be arranged such that the coil assembly accommodated in the groove portion and the portion of the core adjacent to the opening in the groove portion in the radial direction overlap in the radial direction. Therefore, the thrust magnetic bearing can restrict the movement of the coil assembly toward the opening side of the groove portion and properly hold the coil assembly in the groove portion of the core. Further, in a second aspect of the present disclosure, on the premise of the first aspect described above, the groove portion (521) may include a housing portion (521B) in which the coil assembly (530) is accommodated,the outer diameter (D2) of the opening (521A) may be shorter than an outer diameter (D3) of the housing portion (521B) in a part of or an entirety of the circumferential direction, or the inner diameter of the opening (521A) may be longer than an inner diameter (D4) of the housing portion (521B) in a part of or an entirety of the circumferential direction, anda dimension (W1) in an axial direction of the housing portion (521B) may be greater than or equal to a dimension (w1) in the axial direction of the coil assembly (530) in an entirety of the circumferential direction. In a third aspect of the present disclosure, on the premise of the first or second aspect, the outer diameter (D2) of the opening (521A) may be shorter than the outer diameter (d2) of the coil assembly (530) in a part of or an entirety of the circumferential direction, and a difference (δ) between the outer diameter (D2) of the opening (521A) and the outer diameter (d2) of the coil assembly (530) may be less than or equal to 1% of the outer diameter (d2) of the coil assembly (530), or the inner diameter (D1) of the opening (521A) may be longer than the inner diameter (d1) of the coil assembly (530) in a part of or an entirety of the circumferential direction, and a difference (δ) between the inner diameter (D1) of the opening (521A) and the inner diameter (d1) of the coil assembly (530) may be less than or equal to 1% of the inner diameter (d1) of the coil assembly (530). In a fourth aspect of the present disclosure, on the premise of any one of the first to third aspects described above, in a state before the coil assembly (530) is accommodated in the groove portion (521), the outer diameter (D2) of the opening (521A) may be greater than or equal to the outer diameter (d2) of the coil assembly (530) in an entirety of the circumferential direction, and the inner diameter (D1) of the opening (521A) may be less than or equal to the inner diameter (d1) of the coil assembly (530) in an entirety of the circumferential direction. In a fifth aspect of the present disclosure, on the premise of the fourth aspect, the core (520) includes a first core portion (520C) and a second core portion (520D) attached to the first core portion (520C), and in a state where the second core portion (520D) is attached to the first core portion (520C), the outer diameter (D2) of the opening (521A) may be shorter than the outer diameter (d2) of