Rotor, rotary electrical machine, compressor, and refrigeration device

Abstract

A rotor (300) comprises: a rotor core (310) which is disposed in a rotation shaft (110) and which rotates about an axis (AC); and a non-magnetic sleeve (350) which is provided outward of the rotor core (310). The rotor core (310) includes a plurality of first regions (320) which are disposed apart from each other in the circumferential direction and second regions (330) which are disposed between the plurality of first regions (320) in the circumferential direction. The second regions (330) each include a magnetic path (331) demarcated from the first regions (320) by a first gap section (314). An inner surface (351) of the sleeve (350) is disposed so as to contact the outer surfaces (321) of the first regions (320). A first stress which is the greatest among stresses in the first regions (320) is greater than a second stress which is the greatest among stresses in the second regions (330).

Description

Rotor, rotating electric machine, compressor, and refrigeration device

[0001] The present disclosure relates to a rotor, a rotating electric machine, a compressor, and a refrigeration device.

[0002] Patent Document 1 discloses a known technology related to motor rotors. Patent Document 1 discloses a rotor including a rotor core including arc-shaped magnetic paths connected to each other by ribs. Ribs are a cause of leakage flux, so it is desirable to make them as thin as possible. On the other hand, if the ribs are made too thin, the rotor's strength against centrifugal forces and the like decreases. Therefore, there is a trade-off between suppressing leakage flux by the ribs and improving rotor strength.

[0003] Japanese Patent Application Laid-Open No. 2019-180132

[0004] Therefore, a cylindrical tube may be provided on the outer circumferential surface of the rotor core to improve the strength of the rotor using a configuration different from the ribs. For example, when the tube is provided on the outer circumferential surface of the rotor core by shrink-fitting or the like, compressive stress from the tube is applied to the portion that forms the main magnetic path. Therefore, the compressive stress from the tube may deteriorate the magnetic properties of the rotor core.

[0005] A rotor of a first aspect that solves this problem is a rotor for a rotating electric machine, comprising: a rotor core that is arranged on a rotating shaft of the rotating electric machine and configured to rotate around the axis of the rotating shaft; and a cylindrically configured non-magnetic sleeve that is provided on the outside of the rotor core, wherein the rotor core includes a plurality of first regions that are arranged spaced apart from each other in the circumferential direction, and second regions that are arranged between each of the plurality of first regions in the circumferential direction, wherein the second regions include magnetic paths that are separated from the first regions by first gap portions, the inner surface of the sleeve is arranged so as to contact the outer surface of the first region, and the largest first stress among the stresses applied in the first region is greater than the largest second stress among the stresses applied in the second region.

[0006] According to this configuration, the rotor has an increased strength against centrifugal force due to the sleeve, and by suppressing the stress applied to the magnetic path from the sleeve, deterioration of the magnetic characteristics of the magnetic path can be suppressed.

[0007] A rotor according to a second aspect is the rotor according to the first aspect, wherein a radial component of the first stress is greater than a radial component of the second stress. With this configuration, the rotor has an increased strength against centrifugal force due to the sleeve, and can suppress deterioration of the magnetic characteristics of the magnetic path by suppressing the radial component of stress applied from the sleeve to the magnetic path.

[0008] A rotor according to a third aspect is the rotor according to the first or second aspect, in which no magnet is provided in the first gap. With this configuration, in a rotor core in which no magnet is disposed in the first gap, the sleeve improves the strength of the rotor against centrifugal force, and by suppressing the stress applied to the magnetic path from the sleeve, deterioration of the magnetic properties of the magnetic path can be suppressed.

[0009] A rotor according to a fourth aspect is the rotor according to any one of the first to third aspects, wherein the sleeve is in contact with the first region but not with the second region. With this configuration, the sleeve improves the strength of the rotor against centrifugal force, and suppresses the stress applied to the magnetic path from the sleeve, thereby suppressing deterioration of the magnetic properties of the magnetic path.

[0010] A rotor according to a fifth aspect is the rotor according to any one of the first to fourth aspects, wherein the magnetic path includes two or more strip-shaped magnetic paths defined in the radial direction by second gaps, and the sleeve contacts the first region and some of the strip-shaped magnetic paths. With this configuration, the sleeve improves the strength of the rotor against centrifugal force, and suppresses the stress applied to the magnetic path from the sleeve, thereby suppressing deterioration of the magnetic properties of the magnetic path.

[0011] A rotor of a sixth aspect is a rotor of any one of the first to fourth aspects, wherein the magnetic path includes two or more strip-shaped magnetic paths separated in the radial direction by second gap portions, and a rib supporting the magnetic path is arranged in the first gap portion or the second gap portion, and the rib is arranged so that, when viewed from the axial direction, the intersection of the center line of the rib and the center line of the second region, which is drawn imaginarily to pass through the midpoint of the second region in the circumferential direction and the axis of the rotating shaft, is located between the inner surface of the sleeve and the axis of the rotating shaft.

[0012] With this configuration, the ribs are oriented so that the strip-shaped magnetic path approaches the direction of the stress from the sleeve. This increases the component of the stress acting on the ribs in the direction of their extension, reducing the bending stress acting on the rotor. As a result, the rotor can suppress deformation of the ribs due to the sleeve.

[0013] A rotating electric machine according to a seventh aspect is a rotating electric machine including the rotor according to any one of the first to sixth aspects. With this configuration, the rotor has a sleeve that improves the strength of the rotor against centrifugal force, and suppresses the stress applied to the magnetic path from the sleeve, thereby suppressing deterioration of the magnetic characteristics of the magnetic path. Thus, the rotating electric machine can improve energy utilization efficiency.

[0014] A compressor according to an eighth aspect is a compressor including the rotating electric machine according to the seventh aspect. With this configuration, the rotor has a sleeve that improves the strength of the rotor against centrifugal force, and suppresses the stress applied to the magnetic path from the sleeve, thereby suppressing deterioration of the magnetic characteristics of the magnetic path. Therefore, the compressor can improve energy utilization efficiency.

[0015] A refrigeration apparatus according to a ninth aspect is a refrigeration apparatus including the rotating electric machine according to the seventh aspect. With this configuration, the sleeve of the rotor improves the strength of the rotor against centrifugal force, and by suppressing the stress applied to the magnetic path from the sleeve, deterioration of the magnetic properties of the magnetic path can be suppressed. Thus, the energy utilization efficiency of the refrigeration apparatus can be improved.

[0016] It is a schematic configuration diagram of a refrigeration device of a first embodiment. It is a cross-sectional view of the compressor of Figure 1. It is a plan view of the rotating electric machine of Figure 2. It is a plan view of a rotor of the rotating electric machine of Figure 3. It is a schematic view of a rotor of a second embodiment. It is a schematic view of a rotor of a third embodiment. It is a schematic view of a rotor of a modified example.

[0017] First Embodiment A refrigeration system 1, a compressor 10, a rotating electrical machine 100, and a rotor 300 according to a first embodiment will be described with reference to FIGS. 1 to 4. FIG.

[0018] 1, a refrigeration device 1 includes a refrigerant circuit R. The refrigerant circuit R performs, for example, a refrigeration cycle.

[0019] The refrigeration device 1 includes a compressor 10. The refrigeration device 1 includes a rotating electric machine 100. The compressor 10 includes the rotating electric machine 100. In this embodiment, the rotating electric machine 100 is a motor 120. The motor 120 is an inner rotor type motor. The compressor 10 is provided in a refrigerant circuit R of the refrigeration device 1. In addition to the compressor 10, the refrigerant circuit R is also provided with a radiator 20, a pressure reducing mechanism 30 constituted by an expansion valve, and an evaporator 40.

[0020] 2 shows a cross-sectional view of the compressor 10 taken along an axis AC of the rotating shaft 110 of the rotating electric machine 100. The compressor 10 is, for example, a rotary compressor. The compressor 10 is, for example, a swing piston compressor. The compressor 10 may also be a scroll, screw, or turbo compressor.

[0021] The compressor 10 further includes a drive shaft 11 and a compression mechanism 12. The drive shaft 11 is formed integrally with a rotating shaft 110 of the rotating electrical machine 100. The rotating electrical machine 100 is housed in a casing 13. The casing 13 is formed into a cylindrical shape from, for example, a metal material.

[0022] The drive shaft 11 is provided in a casing 13 so as to extend along an axis AC. The drive shaft 11 is configured to rotate around the axis AC. One end of the drive shaft 11 is rotatably supported by a bearing 14. A rotating electric machine 100 is attached near the other end of the drive shaft 11.

[0023] The compression mechanism 12 is housed in a casing 13. The compression mechanism 12 has a cylinder 15 and a piston 16. The piston 16 is connected to the drive shaft 11 and is provided inside the cylinder 15. A cylinder chamber 17 is formed between the inner periphery of the cylinder 15 and the outer periphery of the piston 16.

[0024] The compression mechanism 12 has a suction pipe 18 and a discharge pipe 19. The suction pipe 18 communicates with a cylinder chamber 17 of the compression mechanism 12. The discharge pipe 19 communicates with the internal space of the casing 13.

[0025] Low-pressure refrigerant from the refrigerant circuit R is drawn into a cylinder chamber 17 of the compression mechanism 12 via a suction pipe 18. The compression mechanism 12 compresses the refrigerant in the cylinder chamber 17 with a piston 16 driven by a drive shaft 11. The interior of the casing 13 is filled with high-pressure refrigerant discharged from the compression mechanism 12. The high-pressure refrigerant flows through the rotating electric machine 100 and is then discharged into the refrigerant circuit R via a discharge pipe 19.

[0026] <Rotating Electric Machine> The rotating electric machine 100 will be described with reference to Figures 3 and 4. Figure 3 shows a plan view of the rotating electric machine 100 as seen in the axial direction of a rotating shaft 110 of the rotating electric machine 100.

[0027] The rotating electric machine 100 includes a stator 200. The stator 200 is provided radially outward of the rotor 300 at a distance such that the inner surface of the stator 200 faces the rotor 300 in the radial direction. The stator 200 generates a magnetic field that rotates the rotor 300 around the axis AC of the rotating shaft 110. The stator 200 includes a stator core 210 and a winding 220.

[0028] The stator core 210 is configured by stacking multiple stator plates in the axial direction of the rotating shaft 110. The stator plates are formed, for example, from pressed electromagnetic steel sheets. Adjacent stator plates are connected to each other, for example, by crimping. The stator plates are stacked and insulated from each other. The stator core 210 may be formed from a material including a soft magnetic material. For example, the stator core 210 may be formed from an amorphous alloy or a powder magnetic core.

[0029] Stator core 210 has a back yoke 211 that forms an annular portion on the outer periphery, and a plurality of teeth 212. The plurality of teeth 212 are provided on back yoke 211 so as to extend radially inward from back yoke 211. A winding 220 is wound around each of the plurality of teeth 212. Winding 220 is electrically connected to a power source (not shown).

[0030] The rotating electric machine 100 includes a rotor 300. The rotor 300 rotates about an axis AC of the rotating shaft 110 due to a magnetic field generated by the stator 200. The rotor 300 rotates integrally with the rotating shaft 110. The rotor 300 includes a rotor core 310 disposed on the rotating shaft 110 of the rotating electric machine 100, and a cylindrical, non-magnetic sleeve 350.

[0031] <Rotor Core> The rotor core 310 is configured to rotate around the axis AC of the rotating shaft 110. The rotor core 310 is configured by stacking a plurality of rotor plates in the axial direction of the rotating shaft 110. The rotor plates are formed, for example, from pressed electromagnetic steel plates. Adjacent rotor plates are connected to each other, for example, by crimping. The rotor plates are stacked while being insulated from each other. The rotor core 310 may be formed from a material including a soft magnetic material. For example, the rotor core 310 may be formed from an amorphous alloy or a high-tensile steel plate.

[0032] A hole is provided in the center of each rotor plate. In rotor core 310, these central holes are continuous in the axial direction to form through-hole 311 in which rotating shaft 110 is provided.

[0033] <Each Region of Rotor Core> The rotor core 310 includes a plurality of first regions 320 that are spaced apart from one another in the circumferential direction. The first regions 320 are regions that extend continuously in the radial direction from the outer surface 312 to the inner surface 313 of the rotor core 310. The inner surface 313 is substantially identical to the through holes 311. The first regions 320 are boundary portions of the magnetic poles. In Figure 4, the first regions 320 are indicated by two-dot chain lines. In this embodiment, the rotor core 310 includes four first regions 320, spaced apart from one another in the circumferential direction by 90 degrees.

[0034] The rotor core 310 includes second regions 330 arranged between each of the multiple first regions 320 in the circumferential direction. Each second region 330 includes a magnetic pole formed by a magnetic path 331. The number of second regions 330 corresponds to the number of magnetic poles. In this embodiment, the number of magnetic poles is four. The number of magnetic poles is not limited to four. The rotor core 310 may have magnetic poles that are an even natural number greater than four.

[0035] The second region 330 is separated from the first region 320 by the first gap 314. The second region 330 includes a magnetic path 331 separated from the first region 320 by the first gap 314. Therefore, in the second region 330, the first gap 314 exists on a radial imaginary line connecting the outer surface 312 of the rotor core 310 and the axis AC. Therefore, stress from the sleeve 350 occurs in the radial direction in the first region 320, but bending stress occurs in the second region 330. The magnetic path 331 includes a strip-shaped magnetic path 332 separated in the radial direction by the second gap 315. In the second region 330, the portion other than the first gap 314 and the second gap 315 is the strip-shaped magnetic path 332. There may be one or more strip-shaped magnetic paths 332.

[0036] Rotor core 310 includes third regions 340 that are disposed between each of the plurality of first regions 320 in the circumferential direction and that are separated from second regions 330 in the radial direction by first gaps 314. Third regions 340 are regions of rotor core 310 other than first regions 320 and second regions 330. Third regions 340 are continuous with first regions 320, and the inner surfaces of third regions 340 are substantially identical to through holes 311.

[0037] The rotor core 310 has directions in which magnetic flux flows easily and directions in which magnetic flux flows poorly. In the circumferential direction, the areas between the second regions 330 are regions in which magnetic flux flows easily. That is, the first region 320 is a region in which magnetic flux flows easily. For example, in the radial direction, a virtual line along the center of the first region 320 is defined as the d-axis. Here, the d-axis is the axial direction in which magnetic resistance is minimum. In the radial direction, a virtual line that is electrically and magnetically orthogonal to the d-axis is defined as the q-axis. The q-axis is located at the center of the second region 330 in the circumferential direction and extends radially. The mechanical angle corresponding to the angle at which the d-axis and q-axis are electrically and magnetically orthogonal is, for example, 45 degrees.

[0038] 4, the d-axis and the q-axis are simply indicated as d and q. In this embodiment, the pole refers to the region between adjacent d-axes in the circumferential direction. In other words, the pole refers to the region between adjacent first regions 320 in the circumferential direction.

[0039] The q-axis is not limited to being electrically and magnetically orthogonal to the d-axis. For example, the q-axis may be tilted by a predetermined angle from the angle at which it is electrically and magnetically orthogonal to the d-axis. The predetermined angle is, for example, 5 degrees or more and 15 degrees or less. The predetermined angle is, for example, 10 degrees.

[0040] The strip-shaped magnetic path 332 has a layered structure in the radial direction along the q axis. In this embodiment, the strip-shaped magnetic path 332 has a four-layer structure. The strip-shaped magnetic path 332 is not limited to a four-layer structure as long as it has one or more layers. The strip-shaped magnetic path 332 may have a one-layer structure, a two-layer structure, a three-layer structure, or a five-layer or more structure.

[0041] The strip-shaped magnetic path 332 is curved to have a generally crescent or arc shape that protrudes radially inward. In the portion of the strip-shaped magnetic path 332 that protrudes radially inward, the portion that intersects with the q-axis is located at the innermost radial position. The strip-shaped magnetic path 332 is curved in an arc shape so that both ends of the strip-shaped magnetic path 332 in the longitudinal direction are located on the outer periphery of the rotor core 310. The strip-shaped magnetic path 332 has a curvature that extends along the d-axis toward both ends of the strip-shaped magnetic path 332 in the longitudinal direction and perpendicular to the q-axis toward the longitudinal center. The strip-shaped magnetic path 332 may also be linear.

[0042] In this embodiment, no magnets are provided in the rotor 300. That is, no magnets are provided in the first gap 314, the second gap 315, or the through-hole 311 of the rotor core 310. The motor 120 of this embodiment is a synchronous reluctance motor.

[0043] A magnet may be provided in the rotor 300. The magnet is provided, for example, in the first gap 314 or the second gap 315. <Ribs> Ribs 316 that support the magnetic path 331 are arranged in the first gap 314 or the second gap 315. The ribs 316 are configured to bridge locations other than the ends of each strip-shaped magnetic path 332. The first gap 314 or the second gap 315 is divided into multiple parts by the ribs 316. The ribs 316 are arranged, for example, along the q axis. The arrangement of the ribs 316 is not particularly limited.

[0044] In this embodiment, two ribs 316 are provided symmetrically with respect to the q axis in the outermost second gap 315. Two ribs 316 are provided symmetrically with respect to the q axis in each of the first gap 314 and the second gaps 315 other than the outermost gap, and a rib 316 is provided along the q axis.

[0045] <Sleeve> A sleeve 350 is provided on the outside of the rotor core 310. The sleeve 350 is provided on the outside of the rotor core 310 so as to surround the outer surface 312 of the rotor core 310. The sleeve 350 is formed in a cylindrical shape. The sleeve 350 is attached to the outer surface 312 of the rotor core 310 by, for example, shrink fitting. The material of the sleeve 350 includes, for example, a non-magnetic metal or a carbon fiber reinforced plastic (CFRP). Examples of non-magnetic metals include stainless steel, inconel, duralumin, and titanium.

[0046] An inner surface 351 of the sleeve 350 is disposed so as to contact an outer surface 321 of the first region 320. The sleeve 350 is held by the rotor core 310 so that a surface pressure from the sleeve 350 is applied to the first region 320 more than to the second region 330. The sleeve 350 rotates integrally with the rotor core 310.

[0047] The surface pressure applied by the sleeve 350 to the outer surface 321 of the first region 320 is greater than the surface pressure applied to the outer surface 333 of the second region 330. In other words, the first stress, which is the largest among the stresses applied within the first region 320, is greater than the second stress, which is the largest among the stresses applied within the second region 330. The radial component of the first stress is greater than the radial component of the second stress.

[0048] The rotor core 310 is configured so that the outer diameter of the first region 320 is slightly larger than the outer diameter of the second region 330. Because the outer diameter of the first region 320 is slightly larger than the outer diameter of the second region 330, the surface pressure applied from the sleeve 350 to the outer surface 321 of the first region 320 is greater than the surface pressure applied to the outer surface 333 of the second region 330. Therefore, the radial component of the first stress is greater than the radial component of the second stress.

[0049] The stress inside the first region 320 and the stress inside the second region 330 are measured, for example, by a conventional stress distribution measurement method. Examples of the stress distribution measurement method include strain measurement using a camera, X-ray diffraction, laser light reflection, infrared reflection, etc. By using such a measurement method, it is found that the stress inside the first region 320 in this embodiment is greater than the stress inside the second region 330.

[0050] <Operation of First Embodiment> The operation of this embodiment will be described. Since the surface pressure applied from the sleeve 350 to the outer surface 321 of the first region 320 is greater than the surface pressure applied to the outer surface 333 of the second region 330, stress is less likely to occur inside the second region 330.

[0051] When the rotor core 310 is provided with the ribs 316, there is a risk that the ribs 316 may be deformed due to stress inside the second region 330. In the present embodiment, by suppressing the second stress inside the second region 330, it is possible to suppress deformation of the ribs 316.

[0052] <Effects of First Embodiment> The effects of the first embodiment will be described. (1-1) The rotor 300 is the rotor 300 of the rotating electric machine 100. The rotor 300 is disposed on the rotating shaft 110 of the rotating electric machine 100 and includes a rotor core 310 configured to rotate about an axis AC of the rotating shaft 110, and a cylindrically configured non-magnetic sleeve 350 provided on the outside of the rotor core 310. The rotor core 310 includes a plurality of first regions 320 spaced apart from one another in the circumferential direction, and second regions 330 disposed between the plurality of first regions 320 in the circumferential direction. The second region 330 includes a magnetic path 331 separated from the first region 320 by a first gap 314. An inner surface 351 of the sleeve 350 is disposed so as to contact an outer surface 321 of the first region 320. The first stress, which is the largest among the stresses applied within the first region 320 , is greater than the second stress, which is the largest among the stresses applied within the second region 330 .

[0053] According to this configuration, the rotor 300 can improve the strength of the rotor 300 against centrifugal force by using the sleeve 350, and can also suppress deterioration of the magnetic properties of the magnetic path 331 by suppressing the stress applied to the magnetic path 331 from the sleeve 350.

[0054] Furthermore, since a large surface pressure from the sleeve 350 is applied to the outer surface 321 of the first region 320, magnetic flux is less likely to pass through the first region 320. This reduces the leakage magnetic flux passing through the first region 320. By reducing the leakage magnetic flux, the rotor 300 can improve its torque performance.

[0055] (1-2) The radial component of the first stress is greater than the radial component of the second stress. With this configuration, the sleeve 350 of the rotor 300 improves the strength of the rotor 300 against centrifugal force, and by suppressing the radial component of the stress applied from the sleeve 350 to the magnetic path 331, deterioration of the magnetic characteristics of the magnetic path 331 can be suppressed.

[0056] (1-3) No magnet is provided in the first gap 314. According to this configuration, in the rotor 300, in the rotor core 310 in which no magnet is disposed in the first gap 314, the sleeve 350 improves the strength of the rotor 300 against centrifugal force, and by suppressing the stress applied to the magnetic path 331 from the sleeve 350, deterioration of the magnetic characteristics of the magnetic path 331 can be suppressed.

[0057] (1-4) The rotating electric machine 100 includes the rotor 300. According to this configuration, the sleeve 350 improves the strength of the rotor 300 against centrifugal force, and suppresses the stress applied to the magnetic path 331 from the sleeve 350, thereby suppressing deterioration of the magnetic characteristics of the magnetic path 331. Therefore, the rotating electric machine 100 can improve energy utilization efficiency.

[0058] (1-5) The compressor 10 includes a rotating electric machine 100. According to this configuration, the rotor 300 has the sleeve 350, which improves the strength of the rotor 300 against centrifugal force, and suppresses the stress applied to the magnetic path 331 from the sleeve 350, thereby suppressing deterioration of the magnetic characteristics of the magnetic path 331. Therefore, the compressor 10 can improve energy utilization efficiency.

[0059] (1-6) The refrigeration system 1 includes a rotating electric machine 100. With this configuration, the rotor 300 has the sleeve 350, which improves the strength of the rotor 300 against centrifugal force, and suppresses the stress applied to the magnetic path 331 from the sleeve 350, thereby suppressing deterioration of the magnetic characteristics of the magnetic path 331. This improves the energy utilization efficiency of the refrigeration system 1.

[0060] Second Embodiment A refrigeration system 1, a compressor 10, a rotating electric machine 100, and a rotor 300 according to a second embodiment will be described with reference to Figures 1, 2, and 5. Components in this embodiment that are common to the first embodiment are denoted by the same reference numerals as in the first embodiment, and redundant description will be omitted.

[0061] 5, the sleeve 350 is in contact with the first region 320 but is not in contact with the second region 330. That is, the sleeve 350 is in contact only with the first region 320 and is not in contact with the strip-shaped magnetic path 332.

[0062] In another example, the sleeve 350 may be in contact with the first region 320 and some of the strip-shaped magnetic paths 332. In other words, the sleeve 350 is in contact with the first region 320 and M strip-shaped magnetic paths 332 (which is less than N) out of the N strip-shaped magnetic paths 332, and is not in contact with N-M strip-shaped magnetic paths 332. N is, for example, a natural number equal to or greater than 2. M is a natural number equal to or greater than 1 and smaller than N.

[0063] Whether or not the strip-shaped magnetic path 332 contacts the sleeve 350 is determined depending on the centrifugal force. The centrifugal force is, for example, the product of the diameter of the rotor 300 and the rotation speed of the rotor 300. If the centrifugal force is small or if the rotor 300 has a structure that can withstand the centrifugal force, it is better for the strip-shaped magnetic path 332 not to contact the sleeve 350 in order to prevent deterioration of the magnetic characteristics of the strip-shaped magnetic path 332. In other words, if the strip-shaped magnetic path 332 can be supported only by the rib 316, it is better for the strip-shaped magnetic path 332 not to contact the sleeve 350.

[0064] When the rotor 300 needs to withstand a large centrifugal force, that is, when the rotor 300 is used in a turbo compressor or the like, it is preferable that the strip-shaped magnetic path 332 contact the sleeve 350. In other words, when the strip-shaped magnetic path 332 cannot be supported by the ribs 316 alone, it is preferable that the strip-shaped magnetic path 332 contact the sleeve 350. When the strip-shaped magnetic path 332 contacts the sleeve 350, the strip-shaped magnetic path 332 contacts the sleeve 350 so that the radial component of the first stress is larger than the radial component of the second stress.

[0065] When the strip-shaped magnetic path 332 closest to the axis AC does not contact the sleeve 350 and the other strip-shaped magnetic paths 332 contact the sleeve 350, the rotor core 310 can suppress the second stress while maintaining the strength of the rotor core 310 against centrifugal force. When the strip-shaped magnetic path 332 farthest from the axis AC does not contact the sleeve 350 and the other strip-shaped magnetic paths 332 contact the sleeve 350, the rotor core 310 can suitably improve the strength of the rotor core 310 against centrifugal force.

[0066] When the sleeve 350 does not contact the second region 330 or contacts only a portion of the strip-shaped magnetic path 332, the first gap 314 and the second gap 315 may be filled with resin. This configuration can prevent the resin from causing the strip-shaped magnetic path 332 to become misaligned.

[0067] Effects of the Second Embodiment The effects of the second embodiment will be described. (2-1) The sleeve 350 contacts the first region 320 but does not contact the second region 330. With this configuration, the sleeve 350 improves the strength of the rotor 300 against centrifugal force, and by suppressing the stress applied from the sleeve 350 to the magnetic path 331, deterioration of the magnetic characteristics of the magnetic path 331 can be suppressed.

[0068] (2-2) The magnetic path 331 includes two or more strip-shaped magnetic paths 332 that are separated in the radial direction by the second gap 315. The sleeve 350 contacts the first region 320 and some of the strip-shaped magnetic paths 332. With this configuration, the sleeve 350 improves the strength of the rotor 300 against centrifugal force, and by suppressing the stress applied from the sleeve 350 to the magnetic path 331, deterioration of the magnetic characteristics of the magnetic path 331 can be suppressed.

[0069] <Third embodiment> A refrigeration system 1, a compressor 10, a rotating electric machine 100, and a rotor 300 according to a third embodiment will be described with reference to Figures 1, 2, and 6. In this embodiment, components common to those in the first embodiment are denoted by the same reference numerals as in the first embodiment, and redundant description will be omitted.

[0070] The magnetic path 331 includes two or more strip-shaped magnetic paths 332 that are separated in the radial direction by the second gaps 315. Ribs 316 that support the magnetic path 331 are arranged in the first gaps 314 or the second gaps 315.

[0071] When viewed from the axial direction, the rib 316 is disposed such that an intersection P between a center line 316A of the rib 316 and a center line 330A of the second region 330 is located between the inner surface 351 of the sleeve 350 and the axis AC of the rotating shaft 110. The center line 330A of the second region 330 is an imaginary line drawn to pass through a midpoint DC of the second region 330 in the circumferential direction and the axis AC of the rotating shaft 110. The midpoint DC of the second region 330 is the midpoint of an imaginary line drawn to connect one end and the other end of the second region 330 in the circumferential direction.

[0072] The ribs 316 arranged such that the intersection point P is located between the inner surface 351 of the sleeve 350 and the axis AC of the rotating shaft 110 as viewed from the axial direction may be some of the ribs 316 or all of the ribs 316. In this embodiment, the ribs 316 are arranged such that the intersection point P between the center line 316A of the rib 316 provided in the outermost second gap portion 315 and the center line 330A of the second region 330 is located between the inner surface 351 of the sleeve 350 and the axis AC of the rotating shaft 110 as viewed from the axial direction.

[0073] Effects of the Third Embodiment The effects of the third embodiment will be described. (3-1) The magnetic path 331 includes two or more strip-shaped magnetic paths 332 that are partitioned in the radial direction by the second gaps 315. Ribs 316 that support the magnetic path 331 are arranged in the first gaps 314 or the second gaps 315. The ribs 316 are arranged such that, when viewed from the axial direction, an intersection P between a center line 316A of the rib 316 and a center line 330A of the second region 330 that is virtually drawn to pass through a midpoint DC of the second region 330 in the circumferential direction and the axis AC of the rotating shaft 110 is located between the inner surface 351 of the sleeve 350 and the axis AC of the rotating shaft 110.

[0074] With this configuration, the ribs 316 are oriented so that the band-shaped magnetic paths 332 approach the direction of the stress received from the sleeve 350. This increases the component of the stress acting on the ribs 316 in the direction of extension of the ribs 316, allowing the rotor 300 to reduce the bending stress acting on the ribs 316. Therefore, the rotor 300 can suppress deformation of the ribs 316 caused by the sleeve 350.

[0075] <Modifications> In addition to the first to third embodiments described above, the refrigeration system 1, compressor 10, rotating electric machine 100, and rotor 300 of the present disclosure may be configured in a form that combines, for example, the following modification examples and at least two modification examples that are not mutually contradictory.

[0076] 7, the outer periphery of the rotor core 310 may be connected by bridges 334. With this configuration, the stress acting on the ribs 316 due to centrifugal force is reduced, thereby improving the strength of the rotor core 310 against centrifugal force.

[0077] The ribs 316 may be omitted. In the case where the ribs 316 are omitted, for example, the first gaps 314 and the second gaps 315 may be filled with resin. When the first gaps 314 and the second gaps 315 are filled with resin, the rotor core 310 can prevent the magnetic path 331 from being misaligned.

[0078] The rotating electric machine 100 may be configured as a generator including a rotor 300 having the structure described in each embodiment. The refrigeration device 1 may be an air conditioner. The air conditioner may be a dedicated cooling machine, a dedicated heating machine, or a heating / cooling machine that can switch between cooling and heating. Air conditioners that are heating / cooling machines have a switching mechanism such as a four-way switching valve that switches the circulation direction of the refrigerant. The refrigeration device 1 may also be a water heater, a chiller unit, a cooling device that cools the air inside a storage unit, or the like.

[0079] The refrigeration device 1 may include a blower. When the refrigeration device 1 includes a blower, the blower may include a rotating electric machine 100. When the blower includes the rotating electric machine 100, the rotating electric machine 100 is, for example, a fan motor that rotates a fan of the blower.

[0080] The first to third embodiments of the refrigeration system 1, compressor 10, rotating electric machine 100, and rotor 300 have been described above, but it will be understood that various modifications of the form and details are possible without departing from the spirit and scope of the refrigeration system 1, compressor 10, rotating electric machine 100, and rotor 300 as set forth in the claims.

[0081] 1...refrigeration device, 10...compressor, 100...rotating electric machine, 110...rotating shaft, 300...rotor, 310...rotor core, 313...inner surface, 314...first gap, 315...second gap, 316...rib, 316A...center line, 320...first region, 321...outer surface, 330...second region, 330A...center line, 331...magnetic path, 332...band-shaped magnetic path, 333...outer surface, 350...sleeve, 351...inner surface.

Claims

1. A rotor (300) for a rotating electric machine (100), comprising: a rotor core (310) disposed on a rotating shaft (110) of the rotating electric machine (100) and configured to rotate around an axial center (AC) of the rotating shaft (110); and a cylindrically configured non-magnetic sleeve (350) provided on the outside of the rotor core (310), wherein the rotor core (310) includes a plurality of first regions (320) spaced apart from one another in the circumferential direction, and second regions (330) disposed between each of the plurality of first regions (320) in the circumferential direction, wherein the second regions (330) include magnetic paths (331) separated from the first regions (320) by first gaps (314), and an inner surface (351) of the sleeve (350) is disposed so as to contact an outer surface (321) of the first regions (320), A rotor, wherein a first stress, which is the largest among the stresses acting in the first region (320), is greater than a second stress, which is the largest among the stresses acting in the second region (330).

2. The rotor according to claim 1, wherein the radial component of the first stress is greater than the radial component of the second stress.

3. A rotor according to claim 1 or 2, wherein no magnet is provided in the first gap (314).

4. A rotor according to any one of claims 1 to 3, wherein the sleeve (350) contacts the first region (320) and does not contact the second region (330).

5. A rotor according to any one of claims 1 to 4, wherein the magnetic path (331) includes two or more strip-shaped magnetic paths (332) separated in the radial direction by second gaps (315), and the sleeve (350) contacts the first region (320) and some of the strip-shaped magnetic paths (332).

6. A rotor according to any one of claims 1 to 4, wherein the magnetic path (331) includes two or more strip-shaped magnetic paths (332) defined in the radial direction by second gaps (315), a rib (316) supporting the magnetic path (331) is arranged in the first gap (314) or the second gap (315), and the rib (316) is arranged such that, when viewed in the axial direction, an intersection (P) of a center line (316A) of the rib (316) and a center line (330A) of the second region (330) that is virtually drawn to pass through a midpoint (DC) of the second region (330) in the circumferential direction and the axis (AC) of the rotating shaft (110) is located between an inner surface (351) of the sleeve (350) and the axis (AC) of the rotating shaft (110).

7. A rotating electric machine (100) comprising a rotor (300) according to any one of claims 1 to 6.

8. A compressor (10) comprising the rotating electric machine (100) according to claim 7.

9. A refrigeration system (1) comprising the rotating electric machine (100) according to claim 7.

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