Rotor for rotary electric machine and rotary electric machine

Abstract

To provide a rotor for a rotary electric machine which can inhibit scattering of a magnet with a metal sleeve and inhibit increase of vibration of the rotor caused by heat expansion of the metal sleeve.SOLUTION: A rotor for a rotary electric machine includes: a magnet; a metal sleeve which is formed of a metal material and provided so as to cover the magnet; and at least one non-metal sleeve which is formed of a non-metal material and attached to an outer peripheral surface of the metal sleeve. In the at least one non-metal sleeve, an air gap is formed so as to expose an outer peripheral surface of the metal sleeve partially.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present disclosure relates to a rotor for a rotating electrical machine and a rotating electrical machine.

Background Art

[0002] Patent Document 1 discloses a motor rotor aimed at easily and efficiently attaching a protective tube made of CFRP to the outer peripheral surface of a permanent magnet attached to a rotor shaft. In this rotor, a permanent magnet is attached to the outer peripheral surface of the rotor shaft, and a protective tube made of CFRP covers the entire outer peripheral surface of the permanent magnet. A hollow chamber and a circulation hole are formed in the rotor shaft, and the rotor shaft thermally contracts by circulating liquid nitrogen or the like inside. In a state where the rotor shaft has contracted and its diameter has become smaller, the protective tube is fitted onto the rotor shaft and disposed on the outer peripheral side of the permanent magnet.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] By the way, in a rotor for a rotating electrical machine, when providing a metal sleeve that covers a magnet in order to suppress scattering of the magnet in the case where the magnet is damaged, while the metal sleeve has the merit of having high strength from the viewpoint of suppressing scattering of the magnet, it easily generates heat and expands due to eddy currents. When the metal sleeve expands due to heat generation, there is a concern that a gap is generated inside the metal sleeve and the vibration of the rotor increases during rotation of the rotor.

[0005] In view of the above circumstances, at least one embodiment of the present disclosure aims to provide a rotor for a rotating electrical machine and a rotating electrical machine that can suppress scattering of a magnet by a metal sleeve and suppress an increase in vibration of the rotor caused by thermal expansion of the metal sleeve.

Means for Solving the Problem

[0006] To achieve the above object, a rotor for a rotating electrical machine according to at least one embodiment of the present disclosure is a rotor for a rotating electrical machine, a magnet, a metal sleeve made of a metal material and provided so as to cover the magnet, at least one non-metal sleeve made of a non-metal material and attached to the outer peripheral surface of the metal sleeve, and a gap is formed in the at least one non-metal sleeve so as to partially expose the outer peripheral surface of the metal sleeve.

Advantages of the Invention

[0007] According to at least one embodiment of the present disclosure, there are provided a rotor for a rotating electrical machine and a rotating electrical machine capable of suppressing the scattering of a magnet by a metal sleeve and suppressing an increase in vibration of the rotor due to thermal expansion of the metal sleeve.

Brief Description of the Drawings

[0008]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Modes for Carrying Out the Invention

[0009] Hereinafter, some embodiments of the present disclosure will be described with reference to the accompanying drawings. However, the dimensions, materials, shapes, relative arrangements, etc. of the components described as embodiments or shown in the drawings are not intended to limit the scope of the invention thereto, but are merely illustrative examples. For example, expressions representing relative or absolute arrangements such as "in a certain direction", "along a certain direction", "parallel", "orthogonal", "center", "concentric", or "coaxial" not only strictly represent such arrangements, but also represent states where there are tolerances or relative displacements with angles or distances such that the same function can be obtained. For example, expressions representing that things such as "identical", "equal", and "homogeneous" are in an equal state not only strictly represent an equal state, but also represent states where there are tolerances or differences such that the same function can be obtained. For example, expressions representing shapes such as a rectangular shape or a cylindrical shape not only represent shapes such as a rectangular shape or a cylindrical shape in a geometrically strict sense, but also represent shapes including concave and convex portions, chamfered portions, etc. within a range where the same effect can be obtained. On the other hand, expressions such as "comprising", "having", "including", or "possessing" one component are not exclusive expressions that exclude the existence of other components.

[0010] FIG. 1 is a schematic cross-sectional view showing a part of a motor 2 according to an embodiment of the rotating electrical machine of the present disclosure. As shown in FIG. 1, the motor 2 includes a rotor 4, a bearing device 8 that rotatably supports the rotor 4, and a stator 10.

[0011] The rotor 4 includes a shaft 12, magnets 14, end rings 15, 16, a metal sleeve 18, and a CFRP sleeve 20 as a non-metal sleeve.

[0012] In the following description, unless otherwise specified, the "axial direction" means the axial direction of the rotor 4 (i.e., the axial direction of each of the shaft 12, the magnet 14, the end rings 15, 16, the metal sleeve 18, and the CFRP sleeve 20), the "radial direction" means the radial direction of the rotor 4 (i.e., the radial direction of each of the shaft 12, the magnet 14, the end rings 15, 16, the metal sleeve 18, and the CFRP sleeve 20), and the "circumferential direction" means the circumferential direction of the rotor 4 (i.e., the circumferential direction of each of the shaft 12, the magnet 14, the end rings 15, 16, the metal sleeve 18, and the CFRP sleeve 20).

[0013] The shaft 12 is made of a metal material and extends along the rotation axis O of the rotor 4.

[0014] The magnet 14 is constituted by, for example, a permanent magnet and is attached to the outer peripheral surface 12a of the shaft 12. In the illustrated exemplary form, the magnet 14 has a cylindrical shape, is arranged concentrically with respect to the shaft 12, and the inner peripheral surface 14a of the magnet 14 is fixed to the outer peripheral surface 12a of the shaft 12.

[0015] The end ring 15 is attached to the outer peripheral surface 12a of the shaft 12 on one end side of the magnet 14 in the axial direction, and the end ring 16 is attached to the outer peripheral surface 12a of the shaft 12 on the other end side of the magnet 14 in the axial direction. In the illustrated exemplary form, each of the end rings 15, 16 is arranged concentrically with respect to the shaft 12, and the inner peripheral surface 15a of the end ring 15 and the inner peripheral surface 16a of the end ring 16 are fixed to the outer peripheral surface 12a of the shaft 12.

[0016] The metal sleeve 18 is made of a metal material such as heat-resistant steel, etc., and is attached to the outer peripheral surface 14b of the magnet 14. The metal sleeve 18 has a cylindrical shape, is arranged concentrically with respect to the shaft 12, and the inner peripheral surface 18a of the metal sleeve 18 is fixed to the outer peripheral surface 14b of the magnet 14. In the illustrated exemplary form, the metal sleeve 18 is provided so as to cover the outer peripheral surface 15b of the end ring 15, the outer peripheral surface 14b of the magnet 14, and the outer peripheral surface 16b of the end ring 16.

[0017] The CFRP sleeve 20 is composed of carbon fiber reinforced plastics (CFRP) and is mounted on the outer peripheral surface 18b of the metal sleeve 18. The CFRP sleeve 20 has a cylindrical shape and is arranged concentrically with respect to the shaft 12. The inner peripheral surface 20a of the CFRP sleeve 20 is fixed to the outer peripheral surface 18b of the metal sleeve 18.

[0018] A plurality of voids 24 are formed in the CFRP sleeve 20 so as to partially expose the outer peripheral surface 18b of the metal sleeve 18. That is, when each of the plurality of voids 24 is viewed along the radial direction from the outside in the radial direction, the plurality of voids 24 are formed in the CFRP sleeve 20 so that the outer peripheral surface 18b of the metal sleeve 18 can be seen through each of the plurality of voids 24. In the illustrated exemplary form of the outer peripheral surface 18b of the metal sleeve 18, each of the plurality of voids 24 is a through hole penetrating the CFRP sleeve 20 in the radial direction, and the plurality of voids 24 are formed at different positions in the axial direction, respectively. Further, in the illustrated exemplary form, each of the plurality of voids 24 is formed in a partial range in the circumferential direction.

[0019] Here, the effect exerted by the rotor 4 of the motor 2 will be described. According to the rotor 4, the scattering of the magnet 14 when the magnet 14 is damaged can be suppressed by the metal sleeve 18 covering the magnet 14. Further, by mounting the CFRP sleeve 20 on the outer peripheral surface 18b of the metal sleeve 18, the thermal expansion of the metal sleeve 18 can be suppressed by the CFRP sleeve 20.

[0020] Here, when a CFRP sleeve 20 having a lower thermal conductivity than the metal sleeve 18 is attached to the outer peripheral surface 18b of the metal sleeve 18, heat tends to accumulate inside the CFRP sleeve 20. Therefore, without any special measures, it is likely to be difficult to suppress the temperature rise of the magnet 14 and the metal sleeve 18. On the other hand, in the above-described rotor 4, since the gap 24 is formed in the CFRP sleeve 20 so as to partially expose the outer peripheral surface 18b of the metal sleeve 18, as shown by the arrow f in FIG. 2, the cooling gas (for example, air) flowing in the axial direction between the rotor 4 and the stator 10 can be supplied to the outer peripheral surface 18b of the metal sleeve 18 through the gap 24, and thus the metal sleeve 18 can be cooled. Therefore, it is possible to suppress the scattering of the magnet 14 by the metal sleeve 18 and to suppress an increase in the vibration of the rotor 4 caused by the thermal expansion of the metal sleeve 18.

[0021] In some embodiments, for example, as shown in FIG. 1, when the thickness of the CFRP sleeve 20 is t0 and the size of each gap 24 in the axial direction is d, d>t / 5 may be satisfied. That is, d may be larger than the value obtained by dividing t by 5.

[0022] If the size of the gap 24 in the axial direction is excessively small, convective heat transfer of the cooling gas flowing in the axial direction is less likely to occur. However, according to the above-described rotor 4, by providing the gap 24 that satisfies d>t / 5, as shown in FIG. 2, the flow of the cooling gas along the outer peripheral surface of the CFRP sleeve 20 flows into the gap 24 and vortices are generated, improving the heat transfer coefficient of the convective heat transfer. Therefore, the metal sleeve 18 can be effectively cooled by the cooling gas flowing in the axial direction.

[0023] FIG. 3 is a schematic cross-sectional view showing a part of the motor 2 according to another embodiment. In each configuration of the motor 2 shown in FIG. 3, the reference numerals common to those of the motor 2 shown in FIG. 1 represent the same configurations as those of the motor 2 shown in FIG. 1 unless otherwise specified, and the description thereof is omitted.

[0024] The motor 2 shown in Fig. 3 includes a CFRP sleeve 20, which includes a first sleeve 20A and a second sleeve 20B.

[0025] The first sleeve 20A is made of carbon fiber reinforced plastic and is mounted on the outer peripheral surface 18b of the metal sleeve 18. The first sleeve 20A has a cylindrical shape and is arranged concentrically with respect to the shaft 12, and the inner peripheral surface 20Aa of the first sleeve 20A is fixed to the outer peripheral surface 18b of the metal sleeve 18.

[0026] The second sleeve 20B is made of carbon fiber reinforced plastic and is mounted on the outer peripheral surface 18b of the metal sleeve 18 with an axial gap with respect to the first sleeve 20A. The second sleeve 20B has a cylindrical shape and is arranged concentrically with respect to the shaft 12, and the inner peripheral surface 20Ba of the second sleeve 20B is fixed to the outer peripheral surface 18b of the metal sleeve 18.

[0027] In the embodiment shown in Fig. 3, a gap 24 is formed between the first sleeve 20A and the second sleeve 20B to partially expose the outer peripheral surface 18b of the metal sleeve 18. That is, the gap 24 is formed between the first sleeve 20A and the second sleeve 20B such that the outer peripheral surface 18b of the metal sleeve 18 can be seen through the gap 24 when viewed along the radial direction from the outside in the radial direction. The gap 24 is formed over the entire circumferential direction between the first sleeve 20A and the second sleeve 20B. The gap 24 is formed in a range (the range indicated by the arrow d in Fig. 3) including the central position Pc of the metal sleeve 18 in the axial direction.

[0028] The rotor 4 shown in Fig. 3 may be manufactured by mounting the first sleeve 20A and the second sleeve 20B on the portion of the rotor 4 excluding the first sleeve 20A and the second sleeve 20B (the assembly formed by assembling the shaft 12, the magnets 14, the end rings 15, 16, and the metal sleeve 18) in a state where it is cooled to a temperature lower than that of each of the first sleeve 20A and the second sleeve 20B. That is, the rotor 4 shown in Fig. 3 may be manufactured by shrink-fitting the axially opposite ends of the assembly formed by assembling the shaft 12, the magnets 14, the end rings 15, 16, and the metal sleeve 18 to the first sleeve 20A and the second sleeve 20B, respectively. Further, the rotor 4 shown in Fig. 3 may be manufactured by press-fitting the axially opposite ends of the assembly formed by assembling the shaft 12, the magnets 14, the end rings 15, 16, and the metal sleeve 18 to the first sleeve 20A and the second sleeve 20B, respectively.

[0029] According to the rotor 4 shown in Fig. 3, a gap 24 is formed between the first sleeve 20A and the second sleeve 20B, and since there is no need to provide through holes penetrating in the radial direction in each of the first sleeve 20A and the second sleeve 20B for cooling the metal sleeve 18, it is possible to suppress a decrease in the strength of the first sleeve 20A and the second sleeve 20B and to suppress an increase in processing costs.

[0030] Further, according to the rotor 4 shown in Fig. 3, in view of the fact that the central position Pc of the metal sleeve 18 in the axial direction is likely to cause problems of thermal expansion, the gap 24 is provided in a range including the central position Pc of the metal sleeve 18 in the axial direction. Thereby, it is possible to effectively cool the range including the central position Pc in the metal sleeve 18 and to effectively suppress an increase in the vibration of the rotor 4 due to the thermal expansion of the metal sleeve 18.

[0031] Fig. 4 is a schematic cross-sectional view showing a part of the motor 2 according to another embodiment. In each configuration of the motor 2 shown in Fig. 4, components having the same reference numerals as those of the motor 2 shown in Fig. 3 represent the same configurations as those of the motor 2 shown in Fig. 3 unless otherwise specified, and the description thereof is omitted.

[0032] The rotor 4 shown in Fig. 4 is different from the rotor 4 shown in Fig. 3 in that an annular protrusion 19 protruding radially outward is formed on the outer peripheral surface 18b of the metal sleeve 18. The protrusion 19 is disposed between the first sleeve 20A and the second sleeve 20B.

[0033] In the configuration shown in Fig. 4, the end face 20Ab of the first sleeve 20A facing the second sleeve 20B side contacts the side face 19a of the protrusion 19 on the first sleeve 20A side, thereby positioning the first sleeve 20A in the axial direction. The end face 20Bb of the second sleeve 20B facing the first sleeve 20A side contacts the side face 19b of the protrusion 19 on the second sleeve 20B side, thereby positioning the second sleeve 20B in the axial direction. That is, the protrusion 19 functions as a positioning portion for determining the axial positions of the first sleeve 20A and the second sleeve 20B respectively. For this reason, the manufacturing management of the rotor 4 is easy.

[0034] Also, assuming that the thickness of the metal sleeve 18 in the range S1 where the first sleeve 20A is provided in the axial direction is t1, the thickness of the metal sleeve 18 in the range S2 where the second sleeve 20B is provided in the axial direction is t2, and the thickness of the metal sleeve 18 in the range S3 where the gap 24 is provided in the axial direction is t3, then t3 is greater than each of t1 and t2. That is, t3 > t1 is satisfied and t3 > t2 is satisfied.

[0035] In the range S3 where the gap 24 is provided in the axial direction, the fastening strength of the magnet 14 tends to be locally low. Therefore, by making t3 greater than each of t1 and t2 as described above, it is possible to suppress a decrease in the fastening strength of the magnet 14 in the range S3 where the gap 24 is provided in the axial direction.

[0036] In some embodiments, in the rotor 4 of the motor 2 shown in each of FIGS. 1 to 4, the magnet 14 may be constituted by a plurality of magnet members 21 (see FIG. 5) divided in the axial direction. In the example shown in FIG. 5, the plurality of magnet members 21 are arranged in the axial direction, and each of the plurality of magnet members 21 is formed in an annular shape. Each of the plurality of magnet members 21 is arranged concentrically with respect to the shaft 12, and the inner peripheral surface 21a of the magnet member 21 is fixed to the outer peripheral surface 12a of the shaft 12.

[0037] When the magnet 14 is divided in the axial direction, while the increase in the heat generation amount of the magnet 14 can be suppressed, the heat generation amount of the metal sleeve 18 tends to increase. However, in the rotor 4 shown in each of FIGS. 1 to 4, since the metal sleeve 18 can be effectively cooled by the gap 24, when the magnet 14 is divided in the axial direction, the temperature rise of the magnet 14 and the metal sleeve 18 can be effectively suppressed.

[0038] FIG. 6 is a schematic diagram showing an example of the schematic configuration of a vapor compression machine 50 to which the motor 2 shown in each of FIGS. 1 to 4 can be applied. The exemplary vapor compression machine 50 shown in FIG. 6 includes a motor 2 and a plurality of compressors (two compressors 52 and 54 in the illustrated example) driven by the motor 2. An impeller 52a of the compressor 52 is connected to one end of the shaft 12 of the rotor 4 in the motor 2, and an impeller 54a of the compressor 54 is connected to the other end of the shaft 12 of the rotor 4.

[0039] The compressor 52 compresses the vapor by the rotation of the impeller 52a by the driving force of the motor 2, and the compressor 54 compresses the vapor by the rotation of the impeller 54a by the driving force of the motor 2.

[0040] In the vapor compressor shown in Fig. 6, the vapor, which is the gas compressed by the compressors 52 and 54, and the motor cooling gas (air in the illustrated example) for cooling the motor 2 are different types of gases from each other. In this case, if the pressure of the motor cooling gas is increased to allow a large amount of the motor cooling gas to flow through the motor 2 for cooling the motor 2, the motor cooling gas may leak into the main stream (the flow of vapor) on the side of the compressors 52 and 54. Therefore, there are limits to the pressure and flow rate of the motor cooling gas used for cooling the motor 2.

[0041] In this regard, by applying the motor 2 shown in each of Figs. 1 to 4 to the motor 2 of the vapor compressor 50, it is possible to effectively cool the rotor 4 of the motor 2 while suppressing an increase in the pressure and flow rate of the motor cooling gas, and the motor 2 can be suitably used.

[0042] Further, in the vapor compressor 50 shown in Fig. 6, the motor cooling gas for cooling the rotor 4 of the motor 2 and the cooling gas for cooling the bearing device 8 are the same gas (air in the illustrated example). In such a configuration, when supplying the cooling gas from a common cooling gas supply source to the rotor 4 and the bearing device 8, the proportion of the flow rate of the cooling gas supplied to the rotor 4 decreases by the amount of the cooling gas supplied to the bearing device 8. Therefore, there is a tendency that the rotor 4 needs to be cooled with a small amount of cooling gas.

[0043] In this regard, by applying the motor 2 shown in each of Figs. 1 to 4 to the motor 2 of the vapor compressor 50, the rotor 4 of the motor 2 can be effectively cooled with a small amount of motor cooling gas, so that the motor 2 can be suitably used.

[0044] The present disclosure is not limited to the above-described embodiments, and also includes forms obtained by modifying the above-described embodiments and forms obtained by appropriately combining these forms.

[0045] For example, the motor 2 shown in each of FIGS. 1 to 4 may be applied to a motor that drives a compressor in each stage of a multi-stage steam compressor, or may be applied to a motor that drives a compressor in a heat pump. Also in a heat pump, the heat medium compressed by the compressor and the cooling gas (e.g., air) that cools the motor driving the compressor are different types of gases. Similar to the steam compressor described above, there are limits to the pressure and flow rate of the cooling gas used for cooling the motor 2. Therefore, by applying the motor 2 shown in each of FIGS. 1 to 4 to the motor that drives the compressor of the heat pump, the rotor 4 of the motor 2 can be effectively cooled with a small amount of motor cooling gas, and the motor 2 can be suitably used.

[0046] Also, the rotor 4 shown in each of FIGS. 1 to 4 may be applied to the rotor of a generator and can be used as a rotor for a rotating electrical machine (motor or generator).

[0047] Also, in the rotor 4 shown in each of FIGS. 1 to 4, the CFRP sleeve 20 is exemplified as an example of a non-metallic sleeve mounted on the outer peripheral surface of the metal sleeve 18. However, the non-metallic sleeve mounted on the outer peripheral surface of the metal sleeve 18 may be other materials containing resin, such as fiber-reinforced plastics other than CFRP.

[0048] Also, the rotor 4 shown in each of FIGS. 1 to 4 includes the shaft 12 and the cylindrical magnet 14 mounted on the outer peripheral surface 12a of the shaft 12. However, it is not necessary for the shaft 12 to be provided inside the magnet 14. The rotor 4 may include, for example, a solid cylindrical magnet 14, and the above-described metal sleeve 18 and CFRP sleeve 20.

[0049] Also, a plurality of voids 24 were formed in the CFRP sleeve 20 shown in FIG. 1 so as to partially expose the outer peripheral surface 18b of the metal sleeve 18. However, the number of voids 24 formed in the CFRP sleeve 20 so as to partially expose the outer peripheral surface 18b of the metal sleeve 18 may be one.

[0050] The content described in each of the above embodiments can be understood as follows, for example.

[0051] [1] The rotor for a rotating electrical machine according to at least one embodiment of the present disclosure (for example, the rotor 4 described above) includes a magnet (for example, the magnet 14 described above), a metal sleeve (for example, the metal sleeve 18 described above) made of a metal material and provided so as to cover the magnet, at least one non-metal sleeve (for example, the CFRP sleeve 20, the first sleeve 20A, the second sleeve 20B described above) made of a non-metal material and attached to the outer peripheral surface (for example, the outer peripheral surface 18b described above) of the metal sleeve, and a gap (for example, the gap 24 described above) is formed in the at least one non-metal sleeve so as to partially expose the outer peripheral surface of the metal sleeve.

[0052] According to the rotor for a rotating electrical machine described in [1] above, when the magnet is damaged, the scattering of the magnet can be suppressed by the metal sleeve that covers the magnet. Also, by attaching at least one non-metal sleeve to the outer peripheral surface of the metal sleeve, the thermal expansion of the metal sleeve can be suppressed by the non-metal sleeve. Here, when a non-metal sleeve is attached to the outer peripheral surface of the metal sleeve, heat tends to be trapped inside the non-metal sleeve, so it is likely to be difficult to suppress the temperature rise of the magnet and the metal sleeve without any special measures. However, in the rotor for a rotating electrical machine described in [1] above, since a gap is formed in the at least one non-metal sleeve so as to partially expose the outer peripheral surface of the metal sleeve, it is possible to supply a cooling gas to the outer peripheral surface of the metal sleeve through the gap and cool the metal sleeve. Therefore, it is possible to suppress the scattering of the magnet by the metal sleeve and suppress an increase in the vibration of the rotor due to the thermal expansion of the metal sleeve.

[0053] [2] In some embodiments, in the rotor for a rotating electrical machine described in [1] above, When the thickness of the non-metal sleeve is t0 and the size of the gap in the axial direction of the rotor is d, d > t0 / 5 is satisfied.

[0054] If the size of the gap in the axial direction is excessively small, it becomes difficult for convective heat transfer of the cooling gas flowing in the axial direction to occur. However, according to the rotor for a rotating electrical machine described in [2] above, by providing a gap that satisfies d > t / 5, the flow of the cooling gas along the outer peripheral surface of the non-metal sleeve flows into the gap and vortices are generated, improving the heat transfer coefficient of convective heat transfer. Therefore, the metal sleeve can be effectively cooled by the cooling gas flowing in the axial direction.

[0055] [3] In some embodiments, in the rotor for a rotating electrical machine described in [1] or [2] above, the at least one non-metal sleeve is a non-metal first sleeve (for example, the first sleeve 20A described above) attached to the outer peripheral surface of the metal sleeve, and a non-metal second sleeve (for example, the second sleeve 20B described above) arranged at an interval in the axial direction of the rotor with respect to the non-metal first sleeve and attached to the outer peripheral surface of the metal sleeve, and includes the gap is formed between the non-metal first sleeve and the non-metal second sleeve.

[0056] According to the rotor for a rotating electrical machine described in [3] above, compared with the case where a through-hole penetrating in the radial direction is provided in the non-metal sleeve as the gap, since it is not necessary to provide through-holes in each of the non-metal first sleeve and the non-metal second sleeve, it is possible to suppress a decrease in the strength of the non-metal first sleeve and the non-metal second sleeve and reduce the processing cost.

[0057] [4] In some embodiments, in the rotor for a rotating electrical machine described in [3] above, the gap is formed over the entire circumference in the circumferential direction of the rotor between the non-metal first sleeve and the non-metal second sleeve.

[0058] According to the rotor for a rotating electrical machine described in [4] above, the metal sleeve can be effectively cooled.

[0059] [5] In some embodiments, in the rotor for a rotating electrical machine described in [3] or [4] above, the gap is formed in a range (for example, the range corresponding to the arrow d above) including the central position (for example, the position Pc above) of the metal sleeve in the axial direction.

[0060] According to the rotor for a rotating electrical machine described in [5] above, in view of the fact that the central position of the metal sleeve in the axial direction is likely to cause problems of thermal expansion, the gap is provided in a range including the central position of the metal sleeve in the axial direction. Thereby, the range including the central position of the metal sleeve in the axial direction can be effectively cooled, and an increase in vibration of the rotor due to thermal expansion of the metal sleeve can be effectively suppressed.

[0061] [6] In some embodiments, in the rotor for a rotating electrical machine described in any one of [3] to [5] above, a protruding portion (for example, the protruding portion 19 above) protruding outward in the radial direction of the rotor is formed on the outer peripheral surface of the metal sleeve, and the protruding portion is located between the non-metallic first sleeve and the non-metallic second sleeve.

[0062] According to the rotor for a rotating electrical machine described in [6] above, by bringing the non-metallic first sleeve and the non-metallic second sleeve into contact with both end faces of the protruding portion in the axial direction, it becomes possible to position the non-metallic first sleeve and the non-metallic second sleeve in the axial direction, and the manufacturing management of the rotor for a rotating electrical machine becomes easy.

[0063] [7] In some embodiments, in the rotor for a rotating electrical machine described in [6] above, the protruding portion is formed over the entire circumference of the rotor.

[0064] According to the rotor for a rotating electrical machine described in [7] above, by bringing the non-metallic first sleeve and the non-metallic second sleeve into contact with both end faces of the protruding portion in the axial direction, it becomes possible to position the non-metallic first sleeve and the non-metallic second sleeve in the axial direction, and the manufacturing management of the rotor for a rotating electrical machine becomes easy.

[0065] [8] In some embodiments, in the rotor for a rotating electrical machine described in [6] or [7] above, The end face of the non-metallic first sleeve (for example, the end face 20Ab described above) contacts the side face (for example, the side face 19a described above) on one side of the protruding portion in the axial direction, The end face of the non-metallic second sleeve (for example, the end face 20Bb described above) contacts the side face (for example, the side face 19b described above) on the other side of the protruding portion in the axial direction.

[0066] According to the rotor for a rotating electrical machine described in [8] above, it becomes possible to position the non-metallic first sleeve and the non-metallic second sleeve in the axial direction, and the manufacturing management of the rotor for a rotating electrical machine becomes easy.

[0067] [9] In some embodiments, in the rotor for a rotating electrical machine described in any one of [3] to [8] above, Let the thickness of the metal sleeve in the range (for example, the range S1 described above) where the non-metallic first sleeve is provided in the axial direction be t1, the thickness of the metal sleeve in the range (for example, the range S2 described above) where the non-metallic second sleeve is provided in the axial direction be t2, and the thickness of the metal sleeve in the range (for example, the range S3 described above) where the gap is provided in the axial direction be t3. Then, t3 is larger than each of t1 and t2.

[0068] Since the fastening strength of the magnet tends to be locally low in the range where the gap is provided in the axial direction, by making t3 larger than each of t1 and t2 as described in [9] above, it is possible to suppress a decrease in the fastening strength of the magnet in the range where the gap is provided in the axial direction.

[0069]

[10] In some embodiments, in the rotor for a rotating electrical machine described in [1] or [2] above, The non-metal sleeve is formed with a through-hole (for example, the through-hole corresponding to the gap 24 in FIG. 1) that penetrates in the radial direction of the rotor, The gap is the through-hole.

[0070] According to the rotor for a rotating electrical machine described in

[10] above, compared with the stator for a rotating electrical machine described in [3] above, the number of parts can be reduced.

[0071]

[11] In some embodiments, in the rotor for a rotating electrical machine described in any one of [1] to

[10] above, The metal sleeve is shrink-fitted onto the non-metal sleeve.

[0072] According to the rotor for a rotating electrical machine described in

[11] above, the non-metal sleeve can be easily fixed to the metal sleeve.

[0073]

[12] In some embodiments, in the rotor for a rotating electrical machine described in any one of [1] to

[11] above, The non-metal sleeve is made of a material containing resin.

[0074] According to the rotor for a rotating electrical machine described in

[12] above, since eddy currents do not occur in the non-metal sleeve, while suppressing the thermal expansion of the metal sleeve with the non-metal sleeve, the thermal expansion of the non-metal sleeve can be suppressed.

[0075]

[13] In some embodiments, in the rotor for a rotating electrical machine described in

[12] above, The non-metal sleeve is made of carbon fiber reinforced plastic.

[0076] According to the rotor for a rotating electrical machine described in

[13] above, since eddy currents do not occur in the non-metal sleeve, while suppressing the thermal expansion of the metal sleeve with a lightweight and high-strength non-metal sleeve, the thermal expansion of the non-metal sleeve can be suppressed.

[0077]

[14] The rotating electrical machine according to at least one embodiment of the present disclosure includes a rotor for a rotating electrical machine described in any one of [1] to

[13] above, and a stator (for example, the stator 10 described above).

[0078] According to the rotating electrical machine described in

[14] above, since it includes the rotor for a rotating electrical machine described in any one of [1] to

[13] above, it is possible to suppress the scattering of magnets by a metal sleeve and suppress an increase in vibration of the rotor caused by thermal expansion of the metal sleeve.

Description of Symbols

[0079] 2 Motor 4 Rotor 8 Bearing device 10 Stator 12 Shaft 12a, 14b, 15b, 16b, 18b Outer peripheral surface 14 Magnet 14a, 15a, 16a, 18a, 20Aa, 20Ba, 20a, 21a Inner peripheral surface 15, 16 End ring 18 Metal sleeve 19 Protrusion 19a, 19b Side surface 20 CFRP sleeve 20A First sleeve 20Ab, 20Bb End face 20B Second sleeve 21 Magnet member 24 Gap 50 Vapor compressor 52, 54 Compressor 52a, 54a Impeller

Claims

1. A rotor for a rotating electrical machine, comprising: a magnet; a metal sleeve made of a metal material and provided so as to cover the magnet; at least one non-metal sleeve made of a non-metal material and mounted on the outer peripheral surface of the metal sleeve; wherein the at least one non-metal sleeve has a gap formed therein so as to partially expose the outer peripheral surface of the metal sleeve, and is a rotor for a rotating electrical machine.

2. The stator for a rotating electrical machine according to claim 1, wherein, when the thickness of the non-metal sleeve is t0 and the size of the gap in the axial direction of the rotor is d, d > t0 / 5 is satisfied.

3. The at least one non-metal sleeve includes a non-metal first sleeve mounted on the outer peripheral surface of the metal sleeve, and a non-metal second sleeve which is arranged at an interval in the axial direction of the rotor with respect to the non-metal first sleeve and is mounted on the outer peripheral surface of the metal sleeve, wherein the gap is formed between the non-metal first sleeve and the non-metal second sleeve, and is a rotor for a rotating electrical machine according to claim 1.

4. The rotor for a rotating electrical machine according to claim 3, wherein the gap is formed over the entire circumferential direction of the rotor between the non-metal first sleeve and the non-metal second sleeve.

5. The rotor for a rotating electrical machine according to claim 4, wherein the gap is formed in a range including the position at the center of the metal sleeve in the axial direction.

6. On the outer peripheral surface of the metal sleeve, a protruding portion protruding outward in the radial direction of the rotor is formed, and the protruding portion is located between the non-metal first sleeve and the non-metal second sleeve, and is a stator for a rotating electrical machine according to claim 3.

7. The stator for a rotating electrical machine according to claim 6, wherein the protruding portion is formed over the entire circumferential direction of the rotor.

8. An end face of the non-metal first sleeve contacts a side surface on one side of the protruding portion in the axial direction, and an end face of the non-metal second sleeve contacts a side surface on the other side of the protruding portion in the axial direction, and is a stator for a rotating electrical machine according to claim 6.

9. Let the thickness of the metal sleeve in the range where the non-metal first sleeve is provided in the axial direction be t1, the thickness of the metal sleeve in the range where the non-metal second sleeve is provided in the axial direction be t2, and the thickness of the metal sleeve in the range where the gap is provided in the axial direction be t3. Then, t3 is greater than each of t1 and t2. The rotor for a rotating electrical machine according to claim 3.

10. A through hole penetrating in the radial direction of the rotor is formed in the non-metal sleeve. The gap is the through hole. The rotor for a rotating electrical machine according to claim 1.

11. The metal sleeve is shrink-fitted to the non-metal sleeve. The rotor for a rotating electrical machine according to claim 1.

12. The non-metal sleeve is made of a material containing resin. The rotor for a rotating electrical machine according to claim 1.

13. The non-metal sleeve is made of carbon fiber reinforced plastic. The rotor for a rotating electrical machine according to claim 12.

14. A rotating electrical machine comprising the rotor for a rotating electrical machine according to any one of claims 1 to 13 and a stator.

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