Rotor manufacturing method, rotor and rotating electric machine

Abstract

The present invention prevents the strength from being lowered due to scarring of a magnet reinforcing pipe.　In the present rotor manufacturing method, when manufacturing a rotor (10) comprising a rotor shaft (18), a permanent magnet (20) held on the outer circumference of the rotor shaft (18) via a resin (24), and a magnet reinforcing pipe (22) formed in a cylindrical shape and covering the permanent magnet (20) from the outer circumferential side, the liquid resin (24) is filled between the rotor shaft (18) and the permanent magnet (20), and the permanent magnet (20) is broken and the magnet reinforcing pipe (22) is expanded in diameter by the filling pressure of the resin (24).

Description

[Technical Field]

[0001] The present disclosure relates to a rotating electric machine, and more particularly to a rotor and a manufacturing method thereof. [Background technology]

[0002] In the magnet fixing method for a permanent magnet rotating electric machine described in JP 2005-312250 A, a permanent magnet is fixed to the outer surface of the rotor shaft (rotor shaft) using a fixing means, and then the permanent magnet and the rotor shaft are press-fitted into a cylindrical bind ring (magnet reinforcing tube). The magnet reinforcing tube covers the entire outer surface of the permanent magnet, clamping it down and fixing it to the rotor shaft. This ensures that the permanent magnet is fixed firmly enough to withstand the centrifugal force during high-speed rotation and prevents fragments of the permanent magnet from flying off. Summary of the Invention [Problem to be solved by the invention]

[0003] In the above-mentioned prior art, there is a concern that the magnet reinforcing tube may be damaged when the permanent magnet is press-fitted into the magnet reinforcing tube, thereby reducing the strength of the magnet reinforcing tube.

[0004] In consideration of the above, the present disclosure has an object to provide a rotor manufacturing method, a rotor, and a rotating electric machine that can prevent a decrease in strength due to damage to the magnet reinforcing tube. [Means for solving the problem]

[0005] A first aspect of the rotor manufacturing method is a method for manufacturing a rotor that includes a rotor shaft, permanent magnets held on the outer periphery of the rotor shaft via resin, and a cylindrical magnet reinforcing tube that covers the permanent magnets from the outer periphery, in which the liquid resin is filled between the rotor shaft and the permanent magnets, and the filling pressure of the resin splits the permanent magnets and expands the diameter of the magnet reinforcing tube.

[0006] In a first aspect of the rotor manufacturing method, a rotor is manufactured that includes a rotor shaft, permanent magnets held on the outer periphery of the rotor shaft via resin, and a cylindrical magnet reinforcing tube that covers the permanent magnets from the outer periphery. Liquid resin is filled between the rotor shaft and the permanent magnets. The filling pressure of the resin splits the permanent magnets and expands the diameter of the magnet reinforcing tube. This allows compressive stress to be applied to the permanent magnets between the magnet reinforcing tube and the resin without damaging the magnet reinforcing tube, ensuring sufficient fixing strength for the permanent magnets. This prevents a decrease in strength due to damage to the magnet reinforcing tube.

[0007] A second aspect of the rotor manufacturing method is the first aspect, in which a groove extending in the axial direction is formed on the outer periphery of the rotor shaft, and the liquid resin is filled between the rotor shaft and the permanent magnet through the groove.

[0008] In the rotor manufacturing method of the second aspect, liquid resin is filled between the rotor shaft and the permanent magnet through a groove formed in the outer periphery of the rotor shaft, which allows the gap (clearance) between the rotor shaft and the permanent magnet to be set small, thereby eliminating the need for a positioning jig to ensure concentricity between the rotor shaft and the permanent magnet.

[0009] A third aspect of the rotor manufacturing method is the first aspect, in which a flange-shaped flange portion is formed on a portion of the outer periphery of the rotor shaft, the outer surface of the flange portion is engaged with the inner surface of the permanent magnet to form a gap between the rotor shaft and the permanent magnet, and the liquid resin is filled into the gap.

[0010] In the rotor manufacturing method of the third aspect, the outer peripheral surface of a flange formed on part of the outer periphery of the rotor shaft is engaged with the inner peripheral surface of the permanent magnet, thereby forming a gap between the rotor shaft and the permanent magnet into which liquid resin can be filled. This aspect also eliminates the need for a positioning jig to ensure concentricity between the rotor shaft and the permanent magnet.

[0011] A rotor manufacturing method of the fourth aspect is the same as that of the first aspect, except that a pair of disk-shaped end rings are arranged on both axial sides of the permanent magnet, the rotor shaft is passed through the center of the pair of end rings, and the outer surfaces of the pair of end rings are engaged with the inner surface of the magnet reinforcing tube to form a gap between the rotor shaft and the permanent magnet, and the liquid resin is filled into the gap through a resin filling hole formed in at least one of the pair of end rings.

[0012] In the rotor manufacturing method of the fourth aspect, the pair of end rings ensures concentricity between the rotor shaft and the permanent magnets while forming a gap between the rotor shaft and the permanent magnets for filling with liquid resin. In addition, the liquid resin can be filled into the gap through a resin filling hole formed in at least one of the pair of end rings. This aspect also eliminates the need for a positioning jig to ensure concentricity between the rotor shaft and the permanent magnets.

[0013] A fifth aspect of the rotor manufacturing method is the same as that of the first aspect, except that a pair of disk-shaped end rings are arranged on both axial sides of the permanent magnet, the rotor shaft is passed through the center of the pair of end rings, and the outer surfaces of the pair of end rings are engaged with the inner surface of the magnet reinforcing tube to form a gap between the rotor shaft and the permanent magnet, and the liquid resin is filled into the gap through a resin filling passage formed in the rotor shaft.

[0014] In the rotor manufacturing method of the fifth aspect, the pair of end rings ensures concentricity between the rotor shaft and the permanent magnets, while forming a gap between the rotor shaft and the permanent magnets for filling with liquid resin. In addition, the liquid resin can be filled into the gap through a resin filling channel formed in the rotor shaft. This aspect also eliminates the need for a positioning jig to ensure concentricity between the rotor shaft and the permanent magnets.

[0015] A sixth aspect of the rotor manufacturing method is any of the first to fifth aspects, in which a notch that serves as a starting point when the permanent magnet breaks is formed in the inner circumferential surface of the permanent magnet.

[0016] In the sixth aspect, the permanent magnet can be split as desired by the cuts formed on the inner peripheral surface of the permanent magnet.

[0017] The rotor of the seventh aspect comprises a rotor shaft, a permanent magnet held on the outer periphery of the rotor shaft via resin, and a cylindrical magnet reinforcing tube covering the permanent magnet from the outer periphery, wherein a crack is formed in the permanent magnet in the radial direction, and the crack is filled with the resin.

[0018] In a rotor according to a seventh aspect, a permanent magnet is held on the outer periphery of a rotor shaft via a resin, and the permanent magnet is covered from the outer periphery by a cylindrical magnet reinforcing tube. A crack is formed in the permanent magnet along the radial direction, and the crack is filled with the resin. This rotor can be manufactured by the rotor manufacturing method according to the first aspect, and therefore has the same functions and effects as the first aspect.

[0019] The rotor of an eighth aspect is the rotor of the seventh aspect, wherein a groove extending in the axial direction is formed on the outer periphery of the rotor shaft, and the groove is filled with the resin.

[0020] In the rotor of the eighth aspect, grooves formed on the outer periphery of the rotor shaft are filled with the resin. This rotor can be manufactured by the rotor manufacturing method of the second aspect, and therefore, the same effects and advantages as those of the second aspect can be obtained.

[0021] The rotor of the ninth aspect is the rotor of the seventh aspect, in which the outer surface of a flange portion formed in a flange shape on part of the outer periphery of the rotor shaft engages with the inner surface of the permanent magnet, and the gap formed between the rotor shaft and the permanent magnet is filled with the resin.

[0022] In the rotor of the ninth aspect, the outer peripheral surface of a flange formed on a part of the outer periphery of the rotor shaft engages with the inner peripheral surface of the permanent magnet, and the gap formed between the rotor shaft and the permanent magnet is filled with resin. This rotor can be manufactured by the rotor manufacturing method of the third aspect, and therefore has the same functions and effects as the third aspect.

[0023] The rotor of the tenth aspect is the rotor of the seventh aspect, and is provided with a pair of disk-shaped end rings arranged on both axial sides of the permanent magnet, with the rotor shaft passing through the center of each end ring and each having an outer circumferential surface engaged with the inner circumferential surface of the magnet reinforcing tube, and the gap formed between the rotor shaft and the permanent magnet and a resin filling hole formed in at least one of the pair of end links are filled with the resin.

[0024] In the rotor of the tenth aspect, the rotor shaft passes through the center of a pair of end rings arranged on both axial sides of the permanent magnet, and the outer peripheral surfaces of the pair of end rings engage with the inner peripheral surface of the magnet reinforcing tube. The gap formed between the rotor shaft and the permanent magnet and the resin filling hole formed in at least one of the pair of end links are filled with resin. This rotor can be manufactured by the rotor manufacturing method of the fourth aspect, and therefore provides the same functions and effects as the fourth aspect.

[0025] The rotor of the eleventh aspect is the rotor of the seventh aspect, and is provided with a pair of disk-shaped end rings arranged on both axial sides of the permanent magnet, with the rotor shaft passing through the center of each end ring and with the outer circumferential surface of each end ring engaging with the inner circumferential surface of the magnet reinforcing tube, and the gap formed between the rotor shaft and the permanent magnet and the resin filling flow path formed in the rotor shaft are filled with the resin.

[0026] In the rotor of the eleventh aspect, the rotor shaft passes through the center of a pair of end rings arranged on both axial sides of the permanent magnet, and the outer peripheral surfaces of the pair of end rings engage with the inner peripheral surface of the magnet reinforcing tube. The gap formed between the rotor shaft and the permanent magnet and the resin-filled flow passage formed in the rotor shaft are filled with resin. This rotor can be manufactured by the rotor manufacturing method of the fifth aspect, and therefore has the same functions and effects as the fifth aspect.

[0027] A rotating electric machine according to a twelfth aspect includes the rotor according to any one of the seventh to eleventh aspects, and a stator that generates a rotating magnetic field for the rotor.

[0028] In the rotating electric machine of the twelfth aspect, the rotor rotates due to the rotating magnetic field generated by the stator. This rotor is one of the seventh to eleventh aspects, and therefore the above-mentioned effects can be obtained. [Effects of the Invention]

[0029] As described above, the rotor manufacturing method, rotor, and rotating electric machine according to the present disclosure can prevent a decrease in strength due to damage to the magnet reinforcing tube. [Brief explanation of the drawings]

[0030] [Figure 1] 1 is a cross-sectional view showing the configuration of a main part of a rotating electric machine according to a first embodiment. [Figure 2] FIG. 2 is a cross-sectional view showing the configuration of a rotor according to the first embodiment. [Figure 3] FIG. 3 is a cross-sectional view showing a cut surface taken along line F3-F3 in FIG. 2. [Figure 4] 4 is a cross-sectional view showing a resin filling step in the rotor manufacturing method according to the first embodiment. FIG. [Figure 5] FIG. 5 is a cross-sectional view showing a cut surface taken along line F5-F5 in FIG. [Figure 6] 10 is a cross-sectional view showing a resin filling step in a rotor manufacturing method according to a second embodiment. FIG. [Figure 7] FIG. 7 is a cross-sectional view showing a cut surface taken along line F7-F7 in FIG. [Figure 8] FIG. 6 is a cross-sectional view showing the configuration of a rotor according to a second embodiment. [Figure 9] 10 is a cross-sectional view showing a resin filling step in a rotor manufacturing method according to a third embodiment. FIG. [Figure 10] FIG. 10 is a cross-sectional view showing the configuration of a rotor according to a third embodiment. [Figure 11] FIG. 10 is a cross-sectional view showing a resin filling step in a rotor manufacturing method according to a fourth embodiment. [Figure 12] FIG. 12 is a cross-sectional view showing a cut surface taken along line F12-F12 in FIG. [Figure 13] FIG. 10 is a cross-sectional view showing the configuration of a rotor according to a fourth embodiment. [Figure 14] FIG. 11 is a cross-sectional view showing a resin filling step in a rotor manufacturing method according to a fifth embodiment. [Figure 15] FIG. 15 is a cross-sectional view showing a cut surface taken along line F15-F15 in FIG. [Figure 16] FIG. 10 is a cross-sectional view showing the configuration of a rotor according to a fifth embodiment. [Figure 17] FIG. 10 is a cross-sectional view showing the configuration of a permanent magnet provided in a rotor according to a sixth embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0031] First Embodiment A rotating electric machine 10, a rotor 12, and a method for manufacturing the rotor according to a first embodiment of the present disclosure will be described below with reference to Figures 1 to 5. As shown in Figure 1, the rotating electric machine 10 according to this embodiment is a surface permanent magnetic (SPM) motor in which permanent magnets 20 are held on the outer periphery of the rotor 12. This rotating electric machine 10 includes the rotor 12, a stator 14 that generates a rotating magnetic field for the rotor 12, and a case 16 that houses the rotor 12 and the stator 14. Note that Figure 1 shows a schematic representation of the stator 14.

[0032] 1 to 3, rotor 12 is manufactured by the rotor manufacturing method according to this embodiment, and includes rotor shaft 18, permanent magnets 20 held on the outer periphery of rotor shaft 18 via resin (resin portion) 24, and magnet reinforcing tubes 22 that cover the outer periphery of permanent magnets 20. This rotor 12 rotates around the axis of rotor shaft 18 due to the rotating magnetic field generated by stator 14.

[0033] For example, the rotor shaft 18 has a cylindrical shape with a constant diameter throughout the axial direction. The axial middle portion of the rotor shaft 18 is embedded in resin 24. The resin 24 is, for example, a thermoplastic resin such as PPS (Poly Phenylene Sulfide) or LCP (Liquid Crystal Polymer), or a thermosetting resin such as epoxy resin. The permanent magnets 20 are fixed to the rotor shaft 18 by this resin 24.

[0034] The permanent magnet 20 is formed by splitting a cylindrical shape into multiple pieces in the circumferential direction and is arranged coaxially with the rotor shaft 18. In other words, cracks 21 are formed in the permanent magnet 20 in the radial direction, and these cracks 21 are filled with resin 24. In the example shown in FIG. 3, four cracks 21 are formed in the permanent magnet 20. Note that the permanent magnet 20 may also be split into multiple pieces in the circumferential direction and then molded. In this case, a crack will occur in at least one of the multiple split pieces of the permanent magnet 20.

[0035] A magnet reinforcing tube 22 is attached to the outer periphery of the permanent magnet 20. The magnet reinforcing tube 22 is made of, for example, fiber reinforced plastics (FRP) manufactured by solidifying a fiber sheet with resin. The magnet reinforcing tube 22 is a pipe made of fiber reinforced plastic (FRP) and is formed into a cylindrical shape that is longer in the axial direction than the permanent magnet 20. The inner peripheral surface of the magnet reinforcing tube 22 is in close contact with the outer peripheral surface of the permanent magnet 20, and covers the entire outer peripheral surface of the permanent magnet 20. The magnet reinforcing tube 22 applies compressive stress to the permanent magnet 20 in the radially inward direction. The material of the magnet reinforcing tube 22 may be a metal such as titanium.

[0036] The magnet reinforcing tube 22 is fixed to the rotor shaft 18 via resin 24. The resin 24 is composed of a cylindrical portion 24A that is cylindrically interposed between the rotor shaft 18 and the permanent magnet 20, and a pair of flange portions 24B that protrude in a flange-like manner from both axial ends of the cylindrical portion 24A. The axial dimension of the resin 24 is set to be slightly shorter than the axial dimension of the magnet reinforcing tube 22. The pair of flange portions 24B are arranged on both axial sides of the permanent magnet 20 and are in close contact with the permanent magnet 20 in the axial direction. The outer peripheral surfaces of the pair of flange portions 24B are in close contact with the inner peripheral surfaces of the magnet reinforcing tube 22 at both axial ends.

[0037] 4, when manufacturing the rotor 12 configured as described above, the rotor shaft 18 and magnet reinforcing tube 22 are sandwiched between a pair of injection molding dies 28, 30. The pair of dies 28, 30 have a shaft insertion hole 32 into which both axial ends of the rotor shaft 18 are inserted, and fitting protrusions 34 that fit inside both axial ends of the magnet reinforcing tube 22. This positions the rotor shaft 18 and the magnet reinforcing tube 22 coaxially.

[0038] A cylindrically formed permanent magnet 20 is inserted coaxially beforehand inside the magnet reinforcing tube 22, which is sandwiched between a pair of molds 28, 30, and the permanent magnet 20 is supported by the pair of molds 28, 30 via the magnet reinforcing tube 22. The outer diameter of the permanent magnet 20 inserted inside the magnet reinforcing tube 22 is set to be equal to or slightly smaller than the inner diameter of the magnet reinforcing tube 22. This prevents the magnet reinforcing tube 22 from being damaged when the permanent magnet 20 is inserted inside the magnet reinforcing tube 22.

[0039] 5, a cylindrical gap 26A is formed between the rotor shaft 18 supported by the pair of molds 28, 30 and the permanent magnet 20. In addition, a pair of flange-shaped gaps 26B communicating with the gap 26A is formed between the pair of molds 28, 30 and the permanent magnet 20. The cylindrical gap 26A corresponds to the cylindrical portion 24A of the resin 24, and the flange-shaped gap 26B corresponds to the flange portion 24B of the resin 24.

[0040] One of the molds 28 is formed with a resin filling gate 36 that communicates with one of the gaps 26B, and liquid resin 24 is filled into the gaps 26A and 26B through this resin filling gate 36. At this time, the filling pressure of the high-pressure resin 24 filling the gaps 26A and 26B causes the permanent magnet 20 to crack. As a result, the filling pressure of the high-pressure resin 24 acts on the inner circumferential surface of the magnet reinforcing tube 22, expanding the diameter of the magnet reinforcing tube 22. After the resin 24 hardens, the rotor 12 is ejected from between the pair of molds 28, 30. This completes the rotor 12 shown in FIGS. 2 and 3. In the completed rotor 12, as shown in FIG. 3, cracks 21 are formed in the permanent magnet 20 and are filled with the resin 24.

[0041] In the rotating electric machine 10 configured as described above, the rotor 12 rotates due to the rotating magnetic field generated by the stator 14. The rotor 12 includes a rotor shaft 18, permanent magnets 20 held on the outer periphery of the rotor shaft 18, and a cylindrical magnet reinforcing tube 22 that encases the permanent magnets 20 from the outer periphery. When manufacturing this rotor 12, a liquid resin 24 is filled between the rotor shaft 18 and the permanent magnets 20. The filling pressure of the resin 24 splits the permanent magnets 20, expanding the diameter of the magnet reinforcing tube 22. This allows compressive stress to be applied to the permanent magnets 20 between the magnet reinforcing tube 22 and the resin 24 without damaging the magnet reinforcing tube 22, thereby ensuring sufficient fixing strength for the permanent magnets 20. This prevents a decrease in strength due to damage to the magnet reinforcing tube 22. As a result, it is possible to provide a rotor 12 that can withstand centrifugal forces during high-speed rotation, contributing to improved quality of the rotor 12.

[0042] Furthermore, in the prior art described in the Background section, there is a concern that the magnet reinforcing tube may be scraped when the permanent magnet is press-fitted into the magnet reinforcing tube, resulting in failure to achieve the desired tightening margin. Furthermore, in order to press-fit the permanent magnet into the magnet reinforcing tube, the outer and inner diameters of the permanent magnet and the magnet reinforcing tube must be machined with high precision, which complicates manufacturing. In this regard, the present embodiment does not require press-fitting the permanent magnet 20 into the magnet reinforcing tube 22. This prevents scraping of the magnet reinforcing tube 22 and simplifies manufacturing, eliminating the need to machine the outer and inner diameters of the permanent magnet 20 and the magnet reinforcing tube 22 with high precision. Furthermore, cracking of the permanent magnet 20 reduces eddy currents. This improves the performance of the rotating electric machine 10.

[0043] Next, other embodiments of the present disclosure will be described. Note that the same reference numerals as in the previously described embodiments are used to designate configurations and operations that are basically the same as those in the previously described embodiments, and descriptions thereof will be omitted.

[0044] <Second embodiment> FIG. 6 shows a cross-sectional view of a resin filling step in a rotor manufacturing method according to a second embodiment of the present disclosure, and FIG. 7 shows a cross-sectional view of a section taken along line F7-F7 in FIG. 6. FIG. 8 shows a cross-sectional view of a rotor 40 manufactured by the rotor manufacturing method according to the second embodiment of the present disclosure. In this embodiment, the outer diameter of the rotor shaft 18 is set to be equal to or slightly smaller than the inner diameter of the permanent magnets 20. A groove 42 extending in the axial direction is formed on the outer periphery of the rotor shaft 18. Liquid resin 24 is filled between the rotor shaft 18 and the permanent magnets 20 through this groove 42. The filling pressure of this resin 42 splits the permanent magnets 20, expanding the diameter of the magnet reinforcing tube 22.

[0045] In this embodiment, the configuration other than that described above is the same as in the first embodiment, and basically the same actions and effects as in the first embodiment can be obtained. Moreover, in this embodiment, liquid resin 24 is filled between rotor shaft 18 and permanent magnet 20 through groove 42 formed on the outer periphery of rotor shaft 18, so the gap (clearance) between rotor shaft 18 and permanent magnet 20 can be set small. As a result, a positioning jig for ensuring concentricity between rotor shaft 18 and permanent magnet 20 is not required.

[0046] <Third embodiment> Fig. 9 shows a cross-sectional view of a resin filling step in a rotor manufacturing method according to a third embodiment of the present disclosure. Fig. 10 shows a cross-sectional view of a rotor 50 manufactured by the rotor manufacturing method according to the third embodiment. In this embodiment, a flange-shaped flange portion 52 is formed on a portion of the outer periphery of the rotor shaft 18. The outer periphery of this flange portion 52 engages (contacts) with the inner periphery of the permanent magnet 20, thereby arranging the permanent magnet 20 coaxially with the rotor shaft 18 and forming a gap 26A between the rotor shaft 18 and the permanent magnet 20 for filling with liquid resin 24. The filling pressure of high-pressure resin 42 filled into this gap 26A and flange-shaped gap 26B splits the permanent magnet 20 and expands the diameter of the magnet reinforcing tube 22.

[0047] In this embodiment, the configuration other than that described above is the same as in the first embodiment, and basically the same actions and effects as in the first embodiment can be obtained. Moreover, in this embodiment, the outer peripheral surface of the flange 52 formed on a part of the outer periphery of the rotor shaft 18 is engaged with the inner peripheral surface of the permanent magnet 20, thereby forming a cylindrical gap 26A between the rotor shaft 18 and the permanent magnet 20 into which liquid resin 24 is filled, and therefore a positioning jig for ensuring concentricity between the rotor shaft 18 and the permanent magnet 20 is not required.

[0048] <Fourth embodiment> FIG. 11 shows a cross-sectional view of a resin filling step in a rotor manufacturing method according to a fourth embodiment of the present disclosure, and FIG. 12 shows a cross-sectional view of a section taken along line F12-F12 in FIG. 11 . FIG. 13 shows a cross-sectional view of a rotor 60 according to a fourth embodiment of the present disclosure. In this embodiment, a pair of disk-shaped end rings 62 are disposed on both axial sides of the permanent magnet 20. A through-hole 64 is formed in the center of the pair of end rings 62, through which the rotor shaft 18 passes. The outer diameters of the pair of end rings 62 are set to be equal to or greater than the outer diameter of the permanent magnet 20, and the outer peripheral surfaces of the pair of end rings 62 are engaged with the inner peripheral surface of the magnet reinforcing tube. This forms a cylindrical gap 26A between the rotor shaft 18 and the permanent magnet 20. At least one of the pair of end rings 62 (here, only one) is formed with a resin filling hole 64 that communicates with the gap 26A. Liquid resin 24 is filled into the gap 26A through this resin filling hole 64. The filling pressure of the resin 42 splits the permanent magnet 20 and expands the diameter of the magnet reinforcing tube 22 .

[0049] In this embodiment, the configuration is the same as in the first embodiment except for the above, and basically the same actions and effects as in the first embodiment can be obtained. Moreover, in this embodiment, the pair of end rings 62 can ensure concentricity between the rotor shaft 18 and the permanent magnets 20, while forming a cylindrical gap 26A between the rotor shaft 18 and the permanent magnets 20 for filling with liquid resin 24. In addition, the liquid resin 24 can be filled into the gap 26A through a resin filling hole 64 formed in one of the pair of end rings 62. In this embodiment, too, a positioning jig for ensuring concentricity between the rotor shaft 18 and the permanent magnets 20 is not required.

[0050] <Fifth embodiment> Fig. 14 shows a cross-sectional view of a resin filling step in a manufacturing method of a rotor according to a fifth embodiment of the present disclosure, and Fig. 15 shows a cross-sectional view of a cut surface taken along line F15-F15 in Fig. 14. Fig. 16 shows a cross-sectional view of the configuration of a rotor 70 according to a fifth embodiment of the present disclosure. In this embodiment, as in the fourth embodiment, a pair of disk-shaped end rings 62 are disposed on both axial sides of the permanent magnet 20, and a cylindrical gap 26A is formed between the rotor shaft 18 and the permanent magnet 20.

[0051] A resin filling passage 72 is formed in the rotor shaft 18 instead of the resin filling hole 64 of the fourth embodiment. The resin filling passage 72 extends from one axial end face of the rotor shaft 18 to the other axial end face of the rotor shaft 18 and branches radially outward from the rotor shaft 18 at multiple locations in the axial middle of the rotor shaft 18. The resin filling passage 72 opens at multiple locations on the outer circumferential surface of the rotor shaft 18 and at one axial end face, and communicates with the gap 26A. The one axial end face of the rotor shaft 18 is abutted against one of the molds, so that the resin filling gate 36 and the resin filling passage 72 communicate with each other. Liquid resin 24 is filled into the gap 26A through the resin filling passage 72. The filling pressure of the resin 42 splits the permanent magnet 20 and expands the diameter of the magnet reinforcing tube 22.

[0052] In this embodiment, the configuration is the same as in the first embodiment except for the above, and basically the same actions and effects as in the first embodiment can be obtained. Moreover, in this embodiment, a pair of end rings 62 can be used to ensure concentricity between the rotor shaft 18 and the permanent magnets 20, while a cylindrical gap 26A for filling with liquid resin 24 can be formed between the rotor shaft 18 and the permanent magnets 20. In addition, the liquid resin 24 can be filled into the gap 26A through a resin filling flow path 72 formed in the rotor shaft 18. In this embodiment, too, a positioning jig for ensuring concentricity between the rotor shaft 18 and the permanent magnets 20 is not required.

[0053] Sixth Embodiment FIG. 17 shows a cross-sectional view of the configuration of a permanent magnet 20 provided in a rotor according to a sixth embodiment of the present disclosure. The rotor according to this embodiment has a configuration similar to that of the rotor 12, rotor 40, rotor 50, rotor 60, or rotor 70 described above. However, before resin 24 is filled between the rotor shaft 18 and the permanent magnet 20, the inner circumferential surface of the permanent magnet 20 has notches (recesses) 80 formed along the axial direction of the permanent magnet 20, which serve as starting points for cracking of the permanent magnet 20. In FIG. 17, as an example, four notches 80 are formed on the inner circumferential surface of the permanent magnet 20 at equal intervals around the circumferential direction of the permanent magnet 20. As an example, each notch 80 has a triangular shape with its apex pointing radially outward from the permanent magnet 20 when viewed from the axial direction of the permanent magnet 20. When resin 24 is filled between the rotor shaft 18 and the permanent magnet 20, cracking of the permanent magnet 20 begins at each notch 80. This allows the permanent magnet 20 to be cracked as designed.

[0054] Although the present disclosure has been described above using several embodiments, the present disclosure can be implemented with various modifications without departing from the spirit and scope of the present disclosure. Furthermore, it goes without saying that the scope of the present disclosure is not limited to the above-described embodiments.

[0055] Additionally, the disclosure of Japanese Patent Application No. 2021-171115, filed on October 19, 2021, is incorporated herein by reference in its entirety. All documents, patent applications, and technical standards described herein are incorporated herein by reference to the same extent as if each individual document, patent application, and technical standard was specifically and individually indicated to be incorporated by reference.

Claims

1. A method for manufacturing a rotor including a rotor shaft, a permanent magnet held on an outer periphery of the rotor shaft via a resin, and a cylindrical magnet reinforcing tube covering the outer periphery of the permanent magnet, A manufacturing method of a rotor, comprising filling the space between the rotor shaft and the permanent magnet with the liquid resin, and splitting the permanent magnet and expanding the diameter of the magnet reinforcing tube by the filling pressure of the resin.

2. 2. The method for manufacturing a rotor according to claim 1, further comprising forming a groove extending in the axial direction on the outer periphery of the rotor shaft, and filling the liquid resin between the rotor shaft and the permanent magnet through the groove.

3. 2. A method for manufacturing a rotor as described in claim 1, wherein a flange-shaped portion is formed on a portion of the outer periphery of the rotor shaft, and the outer surface of the flange is engaged with the inner periphery of the permanent magnet to form a gap between the rotor shaft and the permanent magnet, and the liquid resin is filled into the gap.

4. 2. A method of manufacturing a rotor according to claim 1, further comprising the steps of: arranging a pair of disk-shaped end rings on both axial sides of the permanent magnet; passing the rotor shaft through the center of the pair of end rings; engaging the outer peripheral surfaces of the pair of end rings with the inner peripheral surface of the magnet reinforcing tube; and filling the gap with the liquid resin through a resin filling hole formed in at least one of the pair of end rings.

5. 2. A method of manufacturing a rotor according to claim 1, further comprising the steps of: arranging a pair of disk-shaped end rings on both axial sides of the permanent magnet; passing the rotor shaft through the center of the pair of end rings; engaging the outer peripheral surfaces of the pair of end rings with the inner peripheral surface of the magnet reinforcing tube; forming a gap between the rotor shaft and the permanent magnet; and filling the gap with the liquid resin through a resin filling passage formed in the rotor shaft.

6. 6. The method for manufacturing a rotor according to claim 1, wherein a notch, which becomes a starting point when the permanent magnet breaks, is formed on the inner peripheral surface of the permanent magnet.

7. A rotor shaft; a permanent magnet held on the outer periphery of the rotor shaft via a resin; a cylindrical magnet reinforcing tube that covers the permanent magnet from the outer periphery; Equipped with A rotor in which a crack is formed in the radial direction in the permanent magnet, the crack is filled with the resin, the outer surface of a flange formed in a flange-like shape on part of the outer periphery of the rotor shaft is engaged with the inner surface of the permanent magnet, and the gap formed between the rotor shaft and the permanent magnet is filled with the resin.

8. A rotor shaft, a permanent magnet held on the outer periphery of the rotor shaft via a resin; a cylindrical magnet reinforcing tube that covers the permanent magnet from the outer periphery; a pair of disk-shaped end rings arranged on both sides of the permanent magnet in the axial direction, the rotor shaft passing through the center of each end ring, and the outer circumferential surface of each end ring engaging with the inner circumferential surface of the magnet reinforcing tube; Equipped with A rotor in which a crack is formed in the permanent magnet in the radial direction, the crack is filled with the resin, and the gap formed between the rotor shaft and the permanent magnet and the resin filling hole formed in at least one of the pair of end links are filled with the resin.

9. A rotor shaft; a permanent magnet held on the outer periphery of the rotor shaft via a resin; a cylindrical magnet reinforcing tube that covers the permanent magnet from the outer periphery; a pair of disk-shaped end rings arranged on both sides of the permanent magnet in the axial direction, the rotor shaft passing through the center of each end ring, and the outer circumferential surface of each end ring engaging with the inner circumferential surface of the magnet reinforcing tube; Equipped with A rotor in which a crack is formed in the radial direction of the permanent magnet, the crack is filled with the resin, and the gap formed between the rotor shaft and the permanent magnet and the resin filling flow path formed in the rotor shaft are filled with the resin.

10. A rotor according to any one of claims 7 to 9, a stator that generates a rotating magnetic field for the rotor; A rotating electric machine equipped with the above.

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