Rotor manufacturing method and rotor

Abstract

To provide a rotor that can effectively apply an applied pressure to an external peripheral part of a rotor core.SOLUTION: A sleeve 14 of a rotor 10 has a plurality of sleeve layers 22. The plurality of sleeve layers 22 each have a first sleeve layer 221 and a second sleeve layer 222. The first sleeve layer 221 is arranged radially innermost and is fitted with an outer peripheral part 121 of a rotor body 12. The second sleeve layer 222 is arranged on a radially outer side of the first sleeve layer 221 and is fitted therewith. In a first fitting step, the first sleeve layer 221 having a first inner diameter d1 smaller than an outer diameter of the outer peripheral part 121 of the rotor body 12 is press-fitted into and engaged with the outer peripheral part 121. In a second fitting step, a first outer peripheral part 241 of the first sleeve layer 221 fitted with the outer peripheral part 121 of the rotor body 12 is press-fitted to the second sleeve layer 222 having a second inner diameter d2 smaller than a first outer diameter D1 of the first sleeve layer 221, and is fitted with the first outer peripheral part 241.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a method for manufacturing a rotor and a rotor. [Background technology]

[0002] Patent Document 1 discloses a rotor for a rotating electric machine. The rotor includes permanent magnets fixed to the outer peripheral surface of a rotor core, and a cylindrical sleeve that applies a preload to the rotor core by covering the outer peripheral portion of the rotor core. The gap between the sleeve and the magnets is filled with resin and allowed to harden. When the rotor rotates, the sleeve and resin prevent the permanent magnets from moving radially outward due to centrifugal force. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 7049285 Summary of the Invention [Problem to be solved by the invention]

[0004] In general, in a rotor such as that disclosed in Patent Document 1, it is required to suppress the movement of the permanent magnets due to centrifugal force by the sleeve alone, and it is also required to make the sleeve thinner. However, there is a problem that it is difficult to achieve both the pressurizing force on the rotor core by the sleeve and the thinness of the sleeve. In addition, when a single-layered sleeve is attached to the outer periphery of the rotor core, the circumferential stress acting in the circumferential direction of the sleeve is distributed so as to become smaller from the inner periphery toward the outer periphery. Therefore, there is a problem that the sleeve cannot efficiently apply a pressurizing force to the outer periphery of the rotor core.

[0005] The present invention aims to solve the above-mentioned problems. [Means for solving the problem]

[0006] An aspect of the present invention is a manufacturing method of a rotor having a rotor core, a plurality of permanent magnets provided on an outer periphery of the rotor core and arranged in parallel in a circumferential direction of the rotor core, and a cylindrical sleeve that surrounds an outer periphery of a rotor body formed of the rotor core and the plurality of permanent magnets and is fitted to the rotor body and applies a pressure force in a radially inward direction to the plurality of permanent magnets, the sleeve having at least two or more sleeve layers stacked in a radial direction, the plurality of sleeve layers being arranged radially inward in the sleeve and being aligned with the rotor body. The rotor body has a first sleeve layer that is fitted to the outer circumferential portion, and a second sleeve layer that is arranged radially outward of the first sleeve layer and is fitted to the first sleeve layer, and the manufacturing method includes a first fitting process of pressing and fitting the outer circumferential portion of the rotor body into the first sleeve layer, which has a first inner diameter smaller than the outer diameter of the outer circumferential portion of the rotor body, and a second fitting process of pressing and fitting the first outer circumferential portion of the first sleeve layer fitted to the outer circumferential portion of the rotor body into the second sleeve layer, which has a second inner diameter smaller than the first outer diameter of the first sleeve layer. Effect of the Invention

[0007] According to the present invention, the difference between the circumferential stress of the second sleeve layer and the circumferential stress of the first sleeve layer can be suppressed by press-fitting the first sleeve layer, which is fitted to the outer periphery of the rotor body, into the second sleeve layer having a second inner diameter smaller than the first outer diameter of the first sleeve layer. As a result, compared to a configuration in which a pressurizing force is applied to the rotor body by a sleeve of a single layer structure, the pressurizing force in the radially inward direction by the second sleeve layer arranged on the radially outward side can be efficiently increased, and the sleeve can be made thinner. Alternatively, compared to a sleeve of a single layer structure of the same thickness, the rotational speed resistance when the rotor rotates can be improved. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is an overall plan view of a rotor according to an embodiment of the present invention. [Diagram 2]FIG. 2 is an enlarged cross-sectional view of the periphery of a sleeve in the rotor of FIG. [Diagram 3] FIG. 3 is a diagram showing the overall configuration of a rotor manufacturing apparatus. [Figure 4] Fig. 4A is an explanatory diagram showing up to a liquid introducing step of a first fitting step for attaching a first sleeve layer in a rotor manufacturing method using a rotor manufacturing apparatus, and Fig. 4B is an explanatory diagram of an expansion step in the first fitting step. [Diagram 5] Fig. 5A is an explanatory diagram of an inserting step in the first fitting step, and Fig. 5B is an explanatory diagram of a fixing step in the first fitting step. [Figure 6] Fig. 6A is an explanatory view of a second fitting step for attaching a second sleeve layer, and Fig. 6B is an explanatory view showing a fixing step in the second fitting step. [Figure 7] Fig. 7A is an explanatory view of a third fitting step for attaching a third sleeve layer, and Fig. 7B is an explanatory view showing a fixing step in the third fitting step. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] A rotor 10 according to this embodiment constitutes a part of a rotating electric machine having a housing and a stator. As shown in Fig. 1, the rotor 10 includes a rotor body 12 and a sleeve 14 surrounding an outer periphery 121 of the rotor body 12. The rotor body 12 includes a rotor core 16 and a plurality of permanent magnets 18.

[0010] The rotor core 16 is formed in a cylindrical shape from a magnetic material. When viewed from the axial direction of the rotor core 16, the core outer periphery 161 of the rotor core 16 is circular. The core outer periphery 161 of the rotor core 16 has a plurality of accommodating portions 20. The plurality of accommodating portions 20 are arranged in parallel along the circumferential direction of the rotor body 12 and are recessed radially inward relative to the core outer periphery 161 of the rotor core 16. The plurality of accommodating portions 20 are equally spaced apart from one another in the circumferential direction of the rotor core 16. The center of the rotor core 16 has a through hole 162 penetrating in the axial direction. A shaft of a rotating electric machine (not shown) is fitted into the through hole 162.

[0011] The permanent magnets 18 are accommodated in the respective accommodation portions 20 of the rotor core 16. The permanent magnets 18 are provided in the core outer periphery 161 of the rotor core 16 via the accommodation portions 20, and are arranged in parallel in the circumferential direction of the rotor core 16. The permanent magnets 18 are arranged along the circumferential direction of the rotor body 12. The permanent magnets 18 are arranged so that their polarities alternate in the circumferential direction of the rotor core 16. The permanent magnets 18 are exposed, for example, to the core outer periphery 161 of the rotor core 16. Note that the permanent magnets 18 are not limited to being exposed to the outer periphery 121 of the rotor core 16 and arranged flush with the outer periphery surface. The permanent magnets 18 may be arranged radially outward relative to the outer periphery surface of the rotor core 16, or may be arranged radially inward relative to the core outer periphery 161 of the rotor core 16. The permanent magnets 18 may be built into the core outer periphery 161 of the rotor core 16 and not exposed to the outer periphery surface.

[0012] The sleeve 14 is formed in a cylindrical shape from, for example, carbon fiber reinforced resin (CFRP). The sleeve 14 is composed of only a hoop layer in which reinforcing fibers are wound in the circumferential direction. The sleeve 14 surrounds and covers the outer circumferential portion 121 of the rotor body 12, which is composed of the rotor core 16 and the permanent magnets 18. The sleeve 14 is fitted to the outer circumferential portion 121 of the rotor body 12, and applies a radially inward biasing force to the multiple permanent magnets 18. When the rotor 10 rotates, the sleeve 14 prevents the permanent magnets 18 from floating up from the rotor body 12 due to centrifugal force. The inner diameter of the sleeve 14 before being attached to the outer circumferential portion 121 of the rotor body 12 is smaller than the outer diameter D (diameter) of the rotor body 12 (see FIG. 2). Note that the sleeve 14 is not limited to being formed from carbon fiber reinforced resin. The sleeve 14 may be formed from, for example, other fiber reinforced resins (FRPs) including glass fiber reinforced resin (GFRP), metal materials, resin materials, and the like.

[0013] The sleeve 14 has a plurality of sleeve layers 22 laminated in the radial direction. The plurality of sleeve layers 22 includes, for example, a first sleeve layer 221 disposed most radially inward, a second sleeve layer 222 disposed radially outward of the first sleeve layer 221, and a third sleeve layer 223 disposed radially outward of the second sleeve layer 222. That is, the sleeve 14 has a three-layer structure composed of the first to third sleeve layers 221, 222, and 223.

[0014] Note that the sleeve 14 is not limited to the case of being composed of the first to third sleeve layers 221, 222, and 223. As long as it has at least two or more sleeve layers 22 and is structured to be laminated radially on the outer peripheral portion 121 of the rotor body 12, it may have four or more layers. The sleeve 14 is fitted in the order of the first sleeve layer 221, the second sleeve layer 222, and the third sleeve layer 223 from radially inward to radially outward with respect to the outer peripheral portion 121 of the rotor body 12.

[0015] As shown in FIG. 2, the first sleeve layer 221 is formed in a cylindrical shape having a first thickness in the radial direction. The outer periphery of the first sleeve layer 221 is provided with a first outer peripheral portion 241 to which the second sleeve layer 222 is fitted. The first sleeve layer 221 is fitted to the outer peripheral portion 121 of the rotor body 12. In the state before fitting in which the first sleeve layer 221 is not yet fitted to the outer peripheral portion 121 of the rotor body 12, the first inner diameter d1 of the first sleeve layer 221 is smaller than the outer diameter D (diameter) of the outer peripheral portion 121 of the rotor body 12 (d1 < D). The outer peripheral portion 121 of the rotor body 12 is press-fitted into the first sleeve layer 221. The first sleeve layer 221 is fitted radially outward of the outer peripheral portion 121 of the rotor body 12. At this time, the first sleeve layer 221 expands along the circumferential direction of the outer peripheral portion 121 of the rotor body 12. A first circumferential stress F1 (tensile force) is generated in the first sleeve layer 221 along the circumferential direction of the first sleeve layer 221. A first applied pressure 281f (first tightening load) directed radially inward is generated in the first sleeve layer 221. The first applied pressure 281f is applied radially inward from the inner surface of the first sleeve layer 221 to the outer peripheral portion 121 of the rotor body 12. The application direction of the first applied pressure 281f is the direction toward the central axis of the rotor core 16.

[0016] The second sleeve layer 222 is formed in a cylindrical shape having a second thickness in the radial direction. The outer periphery of the second sleeve layer 222 is provided with a second outer peripheral portion 242 into which the third sleeve layer 223 is fitted. In a state before the second sleeve layer 222 is fitted to the first outer peripheral portion 241 of the first sleeve layer 221 fitted to the outer peripheral portion 121 of the rotor body 12, the second inner diameter d2 of the second sleeve layer 222 is smaller than the first outer diameter D1 of the first sleeve layer 221 (the first outer peripheral portion 241) (d2 < D1). The second inner diameter d2 of the second sleeve layer 222 is larger than the first inner diameter d1 of the first sleeve layer 221. The first outer peripheral portion 241 of the first sleeve layer 221 fitted to the outer peripheral portion 121 of the rotor body 12 is press-fitted and fitted into the second sleeve layer 222.

[0017] At this time, the second sleeve layer 222 expands along the circumferential direction of the outer peripheral portion 121 of the rotor body 12. In the second sleeve layer 222, a second circumferential stress F2 (tensile force) is generated along the circumferential direction of the second sleeve layer 222. In the second sleeve layer 222, a second applied pressure 282f (second tightening load) directed radially inward from the inner surface of the second sleeve layer 222 is generated. Through the first sleeve layer 221, the second applied pressure 282f is applied radially inward to the outer peripheral portion 121 of the rotor body 12. The application direction of the second applied pressure 282f is a direction toward the central axis of the rotor core 16.

[0018] The second inner diameter d2 of the second sleeve layer 222 is set such that the second circumferential stress F2 acting on the second sleeve layer 222 and the first circumferential stress F1 acting on the first sleeve layer 221 are substantially equal. For example, the ratio (F2 / F1) of the second circumferential stress F2 to the first circumferential stress F1 is set to be equal to or greater than the circumferential stress generated at the same part (the same diameter part) in the radial direction of the single-layer structure sleeve.

[0019] The third sleeve layer 223 is formed in a cylindrical shape having a third thickness in the radial direction. The third sleeve layer 223 is fitted to the outer peripheral portion 121 of the rotor body 12 via the first and second sleeve layers 221 and 222. Before the third sleeve layer 223 is fitted to the second outer peripheral portion 242 of the second sleeve layer 222 fitted to the first outer peripheral portion 241 of the first sleeve layer 221, the third inner diameter d3 of the third sleeve layer 223 is smaller than the second outer diameter D2 (diameter) of the second sleeve layer 222 fitted to the rotor body 12 (d3 < D2). The second outer peripheral portion 242 of the second sleeve layer 222 is press-fitted and fitted into the third sleeve layer 223.

[0020] At this time, the third sleeve layer 223 expands along the circumferential direction of the outer peripheral portion 121 of the rotor body 12. A third circumferential stress F3 (tensile stress) acts on the third sleeve layer 223 along the circumferential direction of the third sleeve layer 223. A third applied pressure 283f (third clamping load) directed radially inward is generated in the third sleeve layer 223. Through the first and second sleeve layers 221 and 222, the third applied pressure 283f is applied radially inward from the inner surface of the third sleeve layer 223 to the outer peripheral portion 121 of the rotor body 12. The application direction of the third applied pressure 283f is the direction toward the central axis of the rotor core 16.

[0021] The third inner diameter d3 of the third sleeve layer 223 is set such that the third circumferential stress F3 acting on the third sleeve layer 223 and the first and second circumferential stresses F1 and F2 acting on the first and second sleeve layers 221 and 222 are substantially equal. For example, the ratios (F3 / F1, F3 / F2) of the third circumferential stress F3 to the first and second circumferential stresses F1 and F2 are set to be equal to or greater than the circumferential stress generated at the same site (same diameter site) in the radial direction of the single-layer structure sleeve.

[0022] Next, a manufacturing apparatus 50 for the rotor 10 for press-fitting the outer peripheral portion 121 of the rotor body 12 into the sleeve 14 will be described.

[0023] 3, the manufacturing apparatus 50 includes a cylinder jig 52 and a liquid supply unit 54. The cylinder jig 52 is a jig for holding the rotor body 12 and the sleeve 14, and for attaching the sleeve 14 to the outer circumferential portion 121 of the rotor body 12. The liquid supply unit 54 supplies liquid L to the cylinder jig 52.

[0024] The cylinder jig 52 has a support block 56, a connecting portion 58, and a cylinder member 60. The support block 56 is located at the lower portion of the cylinder jig 52. The support block 56 has a support surface 62 that supports the sleeve 14, a recessed portion 64 that is recessed downward from the support surface 62, and a port portion 66 that opens into the recessed portion 64.

[0025] The support surface 62 has a plane perpendicular to the axis of the cylinder jig 52, and abuts against the lower end of the sleeve 14. The support surface 62 supports the lower end of the sleeve 14 so that the lower end of the sleeve 14 can slide in the extension direction of the support surface 62.

[0026] The recess 64 is circular in plan view when viewed from the axial direction of the cylinder jig 52. The recess 64 has a diameter and depth capable of accommodating a head member 68 attached to the tip of the rotor body 12. A positioning member 70 is provided in the recess 64. The positioning member 70 protrudes toward the sleeve 14 and can position the sleeve 14 concentrically with the cylinder member 60 by abutting against the inner circumferential surface of the sleeve 14.

[0027] The port portion 66 is formed in the center of the recess 64 and opens to the bottom of the recess 64. The port portion 66 is connected to the liquid supply portion 54 via a liquid flow path 94.

[0028] The connecting portion 58 is connected to the upper portion of the support block 56 and connects the support block 56 to the cylinder member 60. The connecting portion 58 has an accommodation chamber 72 therein for accommodating the sleeve 14. The accommodation chamber 72 has an inner diameter larger than the cylinder member 60 and the sleeve 14, and forms a gap 74 around the sleeve 14 in which the sleeve 14 can expand. The height of the accommodation chamber 72 in the axial direction of the cylinder jig 52 is, for example, approximately the same as the height of the sleeve 14. The connecting portion 58 has a plurality of discharge ports 76 on its side. The discharge ports 76 have discharge flow paths 78 that radially penetrate the connecting portion 58. The discharge ports 76 discharge the liquid L in the accommodation chamber 72 to the outside.

[0029] The cylinder member 60 has a main body portion 80, a piston 82, and a head member 68. The main body portion 80 has an abutment surface 86 and a cylinder hole 88. The abutment surface 86 is located at the lower part of the main body portion 80. The abutment surface 86 is a plane perpendicular to the axis of the cylinder member 60, and abuts against the upper end part of the sleeve 14. The inner periphery of the sleeve 14 before hydraulic pressure is applied has an inner diameter smaller than the rotor body 12, and is therefore located inward of the cylinder hole 88.

[0030] The abutment surface 86 allows sliding contact with the upper end of the sleeve 14. As the sleeve 14 expands, the upper end of the sleeve 14 slides toward the outer periphery of the abutment surface 86.

[0031] The main body 80 has a cylinder hole 88 therein. The cylinder hole 88 is a circular hole with an inner diameter slightly larger than the rotor body 12, and penetrates the main body 80 in the vertical direction. There is a gap between the cylinder hole 88 and the rotor body 12. The cylinder hole 88 has a length in the vertical direction (axial direction) sufficient to accommodate the rotor body 12 and a part of the piston 82. The cylinder hole 88 has an accommodation groove 801 recessed radially outward. A packing 90 is accommodated in the accommodation groove 801. The packing 90 is made of, for example, an O-ring, and is in liquid-tight contact with the outer circumferential surface of the piston 82. The packing 90 prevents the liquid L from flowing out through the gap between the piston 82 and the cylinder hole 88.

[0032] The piston 82 is housed in the cylinder hole 88. The piston 82 is provided so as to be movable in the axial direction, for example, by a press device P. The piston 82 moves up and down along the cylinder hole 88 while sliding with the cylinder hole 88. A lower end 821 of the piston 82 holds the rotor body 12. The piston 82 has a support pillar 92 that protrudes downward and positions the rotor body 12 on the central axis of the piston 82. The support pillar 92 is inserted through a through hole 162 of the rotor body 12 (rotor core 16).

[0033] The head member 68 is connected to the tip of the support 92. The head member 68 holds the rotor body 12 by sandwiching it between the head member 68 and the piston 82. The head member 68 has the same diameter as the outer periphery 121 of the rotor body 12. After the rotor body 12 is inserted inside the sleeve 14, the head member 68 is released from the connection with the support 92 (see FIG. 6B). When the connection between the head member 68 and the support 92 is released, the rotor body 12 and the sleeve 14 can be removed from the piston 82.

[0034] The liquid supply unit 54 is connected to the port unit 66 via a liquid flow path 94. The liquid supply unit 54 has a relief valve 96, a shutoff valve 98, a pump 100, and a storage tank 102. The liquid flow path 94 has a first flow path 104 that connects the storage tank 102 and the port unit 66, and a second flow path 106 that branches off from the first flow path 104 and connects to the relief valve 96.

[0035] The relief valve 96 is connected to the port portion 66 via the second flow path 106 and the first flow path 104 (liquid flow path 94). The relief valve 96 discharges the liquid L when the liquid pressure exceeds a predetermined value. The relief valve 96 maintains the liquid pressure applied to the sleeve 14 within a range equal to or lower than a predetermined value.

[0036] The storage tank 102 is connected to the port portion 66 via a first flow path 104. The storage tank 102 contains the liquid L to be introduced into the inside of the sleeve 14. As the liquid L, for example, silicon oil, grease, hydraulic oil, or the like is used.

[0037] The shutoff valve 98 and the pump 100 are disposed in the first flow path 104. The shutoff valve 98 is disposed in the first flow path 104 at a position closer to the storage tank 102 than the branch point of the first flow path 104 and the second flow path 106. The shutoff valve 98 closes the first flow path 104 to prevent transmission of hydraulic pressure to the pump 100 and the storage tank 102.

[0038] The pump 100 is disposed between the storage tank 102 and the shutoff valve 98. The pump 100 pumps the liquid L from the storage tank 102 to the port 66.

[0039] Next, a method for manufacturing the rotor 10 by using the manufacturing apparatus 50 to attach the sleeve 14 to the outer periphery 121 of the rotor body 12 will be described.

[0040] First, a first fitting process is performed in which a first sleeve layer 221 constituting the innermost layer of the sleeve 14 is attached to the outer circumferential portion 121 of the rotor body 12. A first inner diameter d1 of the first sleeve layer 221 before being fitted to the rotor body 12 is smaller than an outer diameter D of the outer circumferential portion 121 of the rotor body 12 (see FIG. 2). In the first fitting process, a first manufacturing apparatus 501 is used to attach the first sleeve layer 221.

[0041] 4A, the first sleeve layer 221 is placed in the accommodation chamber 72 of the first manufacturing apparatus 501. The lower end of the first sleeve layer 221 abuts against the support surface 62 of the support block 56, and the upper end of the first sleeve layer 221 abuts against the abutment surface 86 of the main body 80 of the cylinder member 60. As a result, the first sleeve layer 221 is arranged along the axial direction of the cylinder jig 52, and the inner surface of the first sleeve layer 221 is arranged coaxially with the cylinder hole 88.

[0042] Next, in a liquid introduction step of the first fitting step, the liquid L is introduced into the inside of the first sleeve layer 221 through the port portion 66 and the recessed portion 64. The liquid L is supplied via the storage tank 102 and the pump 100 of FIG. 3. As shown in FIG. 4A, the introduction of the liquid L continues until the cylinder hole 88 on the lower side of the head member 68 is filled with the liquid L. When the introduction of the liquid L is completed, the pump 100 of FIG. 3 stops, and the shutoff valve 98 closes the first flow path 104.

[0043] Next, the expansion process shown in Fig. 4B is performed. In the expansion process, the piston 82 is pressed down by the press device P, and as the piston 82 moves downward, the liquid L is pressed down by the head member 68. The liquid L inside the cylinder hole 88 flows toward the inside of the sleeve 14. This increases the liquid pressure inside the first sleeve layer 221. At this time, part of the liquid L flows out from the gap 74 between the upper end of the first sleeve layer 221 and the cylinder member 60 (abutment surface 86) and the gap 74 between the lower end of the first sleeve layer 221 and the support block 56 (support surface 62).

[0044] As the hydraulic pressure increases inside the first sleeve layer 221, a predetermined hydraulic pressure is applied to the first sleeve layer 221. The application of the hydraulic pressure pushes the first sleeve layer 221 radially outward and expands. As a result, the first inner diameter d1' of the first sleeve layer 221 becomes larger than the outer diameter D of the rotor body 12 (d1'>D).

[0045] As shown in FIG. 5A, the piston 82 further descends, and an insertion step is performed in which the rotor body 12 is inserted into the first sleeve layer 221. In the insertion step, since the first inner diameter d1' of the first sleeve layer 221 is larger than the outer diameter D of the rotor body 12, the rotor body 12 is inserted into the first sleeve layer 221 without coming into contact with the first sleeve layer 221. A part of the liquid L located below the head member 68 flows through the gap 74 between the rotor body 12 and the inner circumferential surface of the sleeve 14 and flows out to the outside of the sleeve 14. At this time, the gap 74 between the rotor body 12 and the inner surface of the first sleeve layer 221 narrows and the flow path length increases, making it difficult for the liquid L to flow out to the outside, and therefore the liquid pressure inside the first sleeve layer 221 increases.

[0046] In the insertion process, when the liquid pressure inside the first sleeve layer 221 exceeds a predetermined pressure, a relief valve 96 (see FIG. 3) opens. The relief valve 96 maintains the liquid pressure inside the sleeve 14 at a predetermined value by releasing the liquid L inside the first sleeve layer 221. The relief valve 96 prevents excessive liquid pressure from being generated inside the sleeve 14, thereby preventing damage to the first sleeve layer 221.

[0047] In the fixing process shown in FIG. 5B, when the rotor body 12 is completely inserted into the first sleeve layer 221, the head member 68 abuts against the bottom of the recess 64, and the piston 82 stops descending. After that, the inflow of the liquid L into the first sleeve layer 221 stops, and the liquid pressure inside the first sleeve layer 221 decreases. Due to the decrease in the liquid pressure inside the first sleeve layer 221, the radially outward pressing force on the first sleeve layer 221 disappears, and the first sleeve layer 221 contracts radially inward. As the first sleeve layer 221 contracts radially inward, the first sleeve layer 221 is fitted and fixed to the outer periphery 121 of the rotor body 12. At this time, the first sleeve layer 221 expands along the circumferential direction of the outer periphery 121 of the rotor body 12 from the initial state.

[0048] As shown in FIG. 2, a first circumferential stress F1 corresponding to the difference between the first inner diameter d1 of the first sleeve layer 221 in the initial state (before fitting state) and the outer diameter D of the rotor body 12 is generated in the first sleeve layer 221. A first applied force 281f (first fastening load) corresponding to the difference between the first inner diameter d1 of the first sleeve layer 221 and the outer diameter D of the rotor body 12 is generated in the first sleeve layer 221 toward the radially inward direction, and the first applied force 281f is applied to the outer circumferential portion 121 of the rotor body 12. In a state in which the first applied force 281f is applied, the first sleeve layer 221 is fixed to the outer circumferential portion 121 of the rotor body 12. That is, the first fitting step is a hydraulic expansion press-fitting method that can expand the first sleeve layer 221 by utilizing the hydraulic pressure of the liquid L to press-fit the outer circumferential portion 121 of the rotor body 12 into the first sleeve layer 221.

[0049] Next, a second fitting process is performed to attach the second sleeve layer 222 to the first outer peripheral portion 241 of the first sleeve layer 221 fitted to the outer peripheral portion 121 of the rotor body 12. A second inner diameter d2 of the second sleeve layer 222 before being fitted to the first sleeve layer 221 is smaller than the first outer diameter D1 of the first sleeve layer 221 fitted to the rotor body 12. The second inner diameter d2 of the second sleeve layer 222 is set so as to be able to generate a second circumferential stress F2 that is approximately equal to the first circumferential stress F1 of the first sleeve layer 221.

[0050] 6A, in the second fitting step, a second manufacturing apparatus 502 is used to attach the second sleeve layer 222. The second manufacturing apparatus 502 includes a piston 82, a head member 68, and a cylinder hole 88 corresponding to the first outer diameter D1 of the first sleeve layer 221. That is, the piston 82, the head member 68, and the cylinder hole 88 of the second manufacturing apparatus 502 are each formed with a larger diameter by the thickness of the first sleeve layer 221 in correspondence with the first outer diameter D1 of the first sleeve layer 221, compared to the piston 82, the head member 68, and the cylinder hole 88 of the first manufacturing apparatus 501.

[0051] First, the second sleeve layer 222 is placed in the accommodation chamber 72 of the second manufacturing apparatus 502. The rotor body 12 to which the first sleeve layer 221 is fixed is accommodated in the cylinder hole 88 of the cylinder member 60. Thereafter, a liquid introducing step is performed in which the liquid L is introduced into the inside of the second sleeve layer 222 and the inside of the cylinder hole 88 of the cylinder member 60.

[0052] Next, in the expansion step, the piston 82 is pushed downward, and hydraulic pressure is applied to the inside of the second sleeve layer 222, so that the second sleeve layer 222 expands radially outward. The second inner diameter d2' of the second sleeve layer 222 becomes larger than the first outer diameter D1 of the first sleeve layer 221 (d2'>D1). Then, the rotor body 12 to which the first sleeve layer 221 is fixed is inserted into the inside of the expanded second sleeve layer 222. As shown in FIG. 6B, in the fixing step, the hydraulic pressure is removed and the second sleeve layer 222 contracts radially inward. As the second sleeve layer 222 contracts radially inward, the first outer circumferential portion 241 of the first sleeve layer 221 is press-fitted into the second sleeve layer 222. At this time, the second sleeve layer 222 expands along the circumferential direction of the outer circumferential portion 121 of the rotor body 12 with respect to the initial state.

[0053] As shown in FIG. 2, a second circumferential stress F2 corresponding to the difference between the second inner diameter d2 of the second sleeve layer 222 and the first outer diameter D1 of the first sleeve layer 221 in the initial state (before fitting state) is generated in the second sleeve layer 222. For example, the ratio of the second circumferential stress F2 to the first circumferential stress F1 of the first sleeve layer 221 is set to be equal to or greater than the circumferential stress generated at the same location (same diameter location) in the radial direction of a sleeve having a single layer structure. A second applied force 282f (second tightening load) corresponding to the difference between the second inner diameter d2 of the second sleeve layer 222 and the first outer diameter D1 of the first sleeve layer 221 is generated in the second sleeve layer 222 toward the radially inward direction, and the second applied force 282f is applied to the outer circumferential portion 121 of the rotor body 12 via the first sleeve layer 221. With the second applied force 282f applied, the second sleeve layer 222 is fixed to the first outer circumferential portion 241 of the first sleeve layer 221. That is, the second fitting step is a hydraulic expansion and press-fitting method that utilizes the hydraulic pressure of the liquid L to expand the second sleeve layer 222 and press-fit the first outer circumferential portion 241 of the first sleeve layer 221 into the second sleeve layer 222.

[0054] Next, a third fitting process is performed to attach the third sleeve layer 223 to the second outer peripheral portion 242 of the second sleeve layer 222 fitted to the outer peripheral portion 121 of the rotor body 12. The third inner diameter d3 of the third sleeve layer 223 is smaller than the second outer diameter D2 of the second sleeve layer 222 fitted to the first sleeve layer 221. The third inner diameter d3 of the third sleeve layer 223 is set so as to generate a third circumferential stress F3 that is approximately equal to the first and second circumferential stresses F1, F2 of the first and second sleeve layers 221, 222.

[0055] 7A, in the third fitting step, a third manufacturing apparatus 503 is used for attaching the third sleeve layer 223. The third manufacturing apparatus 503 includes a piston 82, a head member 68, and a cylinder hole 88 corresponding to the second outer diameter D2 of the second sleeve layer 222. That is, the piston 82, the head member 68, and the cylinder hole 88 of the third manufacturing apparatus 503 are each formed with a larger diameter by the thickness of the second sleeve layer 222 in correspondence with the second outer diameter D2 of the second sleeve layer 222 compared to the piston 82, the head member 68, and the cylinder hole 88 of the second manufacturing apparatus 502.

[0056] First, the third sleeve layer 223 is placed in the accommodation chamber 72 of the third manufacturing equipment 503. The rotor body 12 to which the first and second sleeve layers 221, 222 are fixed is accommodated in the cylinder hole 88 of the cylinder member 60. Thereafter, a liquid introducing step is performed in which the liquid L is introduced into the inside of the third sleeve layer 223 and the inside of the cylinder hole 88 of the cylinder member 60.

[0057] Next, in the expansion step, the piston 82 is pushed downward, and hydraulic pressure is applied to the inside of the third sleeve layer 223, causing the third sleeve layer 223 to expand radially outward. After that, the rotor body 12, to which the first and second sleeve layers 221, 222, 222 are fixed, is inserted into the inside of the expanded third sleeve layer 223. As shown in FIG. 7B, in the fixing step, the hydraulic pressure is removed and the third sleeve layer 223 contracts radially inward. As the third sleeve layer 223 contracts radially inward, the second outer circumferential portion 242 of the second sleeve layer 222 is press-fitted into the third sleeve layer 223. At this time, the third sleeve layer 223 expands along the circumferential direction of the outer circumferential portion 121 of the rotor body 12 relative to the initial state.

[0058] As shown in Fig. 2, a third circumferential stress F3 corresponding to the difference between the third inner diameter d3 of the third sleeve layer 223 and the second outer diameter D2 of the second sleeve layer 222 in the initial state (before fitting state) is generated in the third sleeve layer 223. For example, the ratio of the third circumferential stress F3 to the first circumferential stress F1 of the first sleeve layer 221 is set to be equal to or greater than the circumferential stress generated at the same location (same diameter location) in the radial direction of a sleeve having a single layer structure. A third applied force 283f (third tightening load) corresponding to the difference between the third inner diameter d3 of the third sleeve layer 223 and the second outer diameter D2 of the second sleeve layer 222 is generated in the third sleeve layer 223 toward the radially inward direction, and the third applied force 283f is applied to the outer circumferential portion 121 of the rotor body 12 via the first and second sleeve layers 221 and 222. With the third applied pressure 283f applied, the third sleeve layer 223 is fixed to the second outer circumferential portion 242 of the second sleeve layer 222. That is, the second fitting step is a hydraulic expansion and press-fitting method that utilizes the hydraulic pressure of the liquid L to expand the third sleeve layer 223 and press-fit the second outer circumferential portion 242 of the second sleeve layer 222 into the third sleeve layer 223.

[0059] Through the above manufacturing process of the rotor 10, the first to third sleeve layers 221, 222, 223 are laminated in the radial direction in order on the outer circumferential portion 121 of the rotor body 12, and the attachment is completed.

[0060] This embodiment provides the following advantages.

[0061] 1, the rotor 10 has a cylindrical sleeve 14 that surrounds an outer circumferential portion 121 of a rotor body 12 including a rotor core 16 and a plurality of permanent magnets 18, is fitted to the rotor body 12, and applies a radially inward pressure to the plurality of permanent magnets 18. The sleeve 14 includes at least two or more sleeve layers 22 that are stacked radially, and the plurality of sleeve layers 22 include a first sleeve layer 221 that is disposed radially innermost in the sleeve 14 and fitted to the outer circumferential portion 121 of the rotor body 12, and a second sleeve layer 222 that is disposed radially outward of the first sleeve layer 221 and fitted to the first sleeve layer 221. The manufacturing method of the rotor 10 includes a first fitting process in which the outer peripheral portion 121 of the rotor body 12 is press-fitted into a first sleeve layer 221 having a first inner diameter d1 smaller than the outer diameter D of the outer peripheral portion 121 of the rotor body 12, and a second fitting process in which the first outer peripheral portion 241 of the first sleeve layer 221 fitted into the outer peripheral portion 121 of the rotor body 12 is press-fitted into a second sleeve layer 222 having a second inner diameter d2 smaller than the first outer diameter D1 of the first sleeve layer 221.

[0062] According to this manufacturing method, the first sleeve layer 221 fitted to the outer circumferential portion 121 of the rotor body 12 is fitted to the second sleeve layer 222 having a second inner diameter d2 smaller than the first outer diameter D1 of the first sleeve layer 221, thereby suppressing the difference between the second circumferential stress F2 (tension) of the second sleeve layer 222 and the first circumferential stress F1 (tension) of the first sleeve layer 221. In other words, the circumferential stress in the radial direction of the sleeve 14 can be leveled. As a result, compared to a configuration in which a pressurizing force is applied to the rotor body by a sleeve of a single layer structure, the second pressurizing force 282f in the radially inward direction by the second sleeve layer 222 arranged on the radially outward side can be efficiently increased, and therefore the sleeve 14 can be made thinner in the radial direction. Alternatively, compared to a sleeve of a single layer structure of the same thickness, the endurance rotation speed when the rotor 10 rotates can be improved. In other words, compared to a sleeve of a single layer structure, the rotor 10 can be rotated at a higher speed. In this case, the thickness of the sleeve 14 is the total value of the thicknesses of the first sleeve layer 221, the second sleeve layer 222, and the third sleeve layer 223.

[0063] This makes it possible to equalize the first circumferential stress F1 of the first sleeve layer 221 and the second circumferential stress F2 of the second sleeve layer 222, thereby enabling the first and second sleeve layers 221, 222 to apply a substantially uniform pressure to the outer circumferential portion 121 of the rotor body 12.

[0064] The multiple sleeve layers 22 include a third sleeve layer 223 that is arranged radially outward of the second sleeve layer 222 and is fitted into a second outer peripheral portion 242 of the second sleeve layer 222, and a third fitting process is included in which the second outer peripheral portion 242 of the second sleeve layer 222 fitted into the first sleeve layer 221 is pressed into and fitted into the third sleeve layer 223 having a third inner diameter d3 smaller than the second outer diameter D2 of the second sleeve layer 222.

[0065] This effectively increases the third circumferential stress F3 (tension) of the third sleeve layer 223 disposed radially outward of the second sleeve layer 222. The first to third sleeve layers 221, 222, 223 further equalize the circumferential stress in the sleeve 14.

[0066] Since the multiple sleeve layers 22 are formed of carbon fiber reinforced plastic (CFRP), by fitting the multiple sleeve layers 22 to the outer circumferential portion 121 of the rotor body 12, circumferential stress is generated in each sleeve layer 22, and a pressure force acting radially inward can be effectively generated.

[0067] 1, the rotor 10 includes a cylindrical sleeve 14 that surrounds an outer circumferential portion 121 of a rotor body 12 including a rotor core 16 and a plurality of permanent magnets 18, is fitted to the rotor body 12, and applies a radially inward pressure to the plurality of permanent magnets 18. The sleeve 14 includes at least two or more sleeve layers 22 that are stacked radially, and the plurality of sleeve layers 22 include a first sleeve layer 221 that is disposed radially innermost in the sleeve 14 and fitted to the outer circumferential portion 121 of the rotor body 12, and a second sleeve layer 222 that is disposed radially outward of the first sleeve layer 221 and fitted to the first sleeve layer 221.

[0068] According to this configuration, the first sleeve layer 221 and the second sleeve layer 222 radially outward of the first sleeve layer 221 are fitted in order to the outer circumferential portion 121 of the rotor body 12, thereby suppressing and leveling the difference between the second circumferential stress F2 of the second sleeve layer 222 and the first circumferential stress F1 of the first sleeve layer 221. As a result, compared to a configuration in which a pressurizing force is applied to the rotor body by a sleeve of a single layer structure, the pressurizing force applied from the second sleeve layer 222 disposed radially outward can be efficiently increased, and the sleeve 14 can be made thinner. Alternatively, compared to a sleeve of a single layer structure of the same thickness, the number of rotations that the rotor 10 can withstand when rotating can be improved.

[0069] The above embodiment can be summarized as follows.

[0070] The above embodiment is a method for manufacturing a rotor (10) having a rotor core (16), a plurality of permanent magnets (18) provided on an outer circumferential portion (121) of the rotor core and arranged in parallel in the circumferential direction of the rotor core, and a cylindrical sleeve (14) that surrounds an outer circumferential portion of a rotor body (12) formed of the rotor core and the plurality of permanent magnets and is fitted to the rotor body to apply a pressure force in a radially inward direction to the plurality of permanent magnets, the sleeve having at least two or more sleeve layers (22) stacked in the radial direction, the plurality of sleeve layers being arranged radially inward in the sleeve and being aligned in a radially inward direction of the rotor body. The rotor body has a first sleeve layer (221) that is fitted to the outer circumferential portion, and a second sleeve layer (222) that is arranged radially outward of the first sleeve layer and is fitted to the first sleeve layer, and the manufacturing method includes a first fitting process of pressing the outer circumferential portion of the rotor body into the first sleeve layer, the first sleeve layer having a first inner diameter (d1) smaller than the outer diameter (D) of the outer circumferential portion of the rotor body, and a second fitting process of pressing the first outer circumferential portion (241) of the first sleeve layer fitted to the outer circumferential portion of the rotor body into the second sleeve layer having a second inner diameter (d2) smaller than the first outer diameter (D1) of the first sleeve layer.

[0071] According to this manufacturing method, the first sleeve layer fitted to the outer periphery of the rotor body is press-fitted into the second sleeve layer having a second inner diameter smaller than the first outer diameter of the first sleeve layer, thereby suppressing the difference between the circumferential stress (tension) of the second sleeve layer and the circumferential stress (tension) of the first sleeve layer. As a result, compared to a configuration in which a pressurizing force is applied to the rotor body by a sleeve of a single layer structure, the pressurizing force in the radially inward direction by the second sleeve layer arranged on the radially outward side can be efficiently increased, thereby making it possible to make the sleeve thinner. Alternatively, compared to a sleeve of a single layer structure of the same thickness, the rotational speed resistance when the rotor rotates can be improved.

[0072] According to this manufacturing method, by leveling out the first circumferential stress in the first sleeve layer and the second circumferential stress in the second sleeve layer, it becomes possible for the first and second sleeve layers to apply a substantially uniform pressure to the outer periphery of the rotor body.

[0073] The multiple sleeve layers include a third sleeve layer (223) that is arranged radially outward of the second sleeve layer and is fitted into a second outer peripheral portion (242) of the second sleeve layer, and a third fitting process is provided in which the second outer peripheral portion of the second sleeve layer fitted into the first sleeve layer is pressed into and fitted into the third sleeve layer having a third inner diameter (d3) smaller than the second outer diameter (D2) of the second sleeve layer.

[0074] According to this manufacturing method, it is possible to effectively increase the third circumferential stress (tension) of the third sleeve layer disposed radially outward of the second sleeve layer. The first to third sleeve layers further equalize the circumferential stress within the sleeve.

[0075] The multiple sleeve layers are formed from carbon fiber reinforced plastic (CFRP).

[0076] According to this manufacturing method, by fitting a plurality of sleeve layers onto the outer periphery of the rotor body, circumferential stress is generated in each sleeve layer, and a radially inward biasing force can be effectively generated.

[0077] A rotor having a rotor core, a plurality of permanent magnets provided on the outer periphery of the rotor core and arranged in parallel in the circumferential direction of the rotor core, and a cylindrical sleeve that surrounds the outer periphery of a rotor body consisting of the rotor core and the plurality of permanent magnets and is fitted into the rotor body to apply a radially inward pressure to the plurality of permanent magnets, wherein the sleeve has at least two or more sleeve layers stacked radially, and the plurality of sleeve layers include a first sleeve layer that is located radially inward on the sleeve and is fitted into the outer periphery of the rotor body, and a second sleeve layer that is located radially outward of the first sleeve layer and is fitted into the first sleeve layer.

[0078] According to this configuration, by fitting the first sleeve layer and the second sleeve layer radially outward of the first sleeve layer in that order to the outer periphery of the rotor body, the difference between the circumferential stress (tension) of the second sleeve layer and the circumferential stress (tension) of the first sleeve layer can be suppressed and leveled out. As a result, compared to a configuration in which a pressurizing force is applied to the rotor body by a sleeve of a single layer structure, the pressurizing force applied from the second sleeve layer disposed radially outward can be efficiently increased, and the sleeve can be made thinner. Alternatively, compared to a sleeve of a single layer structure of the same thickness, the number of rotations that the rotor can withstand when rotating can be improved.

[0079] According to this configuration, by leveling out the first circumferential stress in the first sleeve layer and the second circumferential stress in the second sleeve layer, it becomes possible for the first and second sleeve layers to apply a substantially uniform pressure to the outer periphery of the rotor body.

[0080] The present invention is not limited to the above disclosure, and various configurations can be adopted without departing from the gist of the present invention. [Explanation of symbols]

[0081] 10...Rotor 12...Rotor body 14...Sleeve 16...Rotor core 18...Permanent magnet 22…Sleeve layer 121…Outer periphery 221…First sleeve layer 222…Second sleeve layer 223…Third sleeve layer

Claims

1. A rotor core; A plurality of permanent magnets are provided on an outer periphery of the rotor core and arranged in parallel in a circumferential direction of the rotor core; a cylindrical sleeve that surrounds an outer periphery of a rotor body including the rotor core and the plurality of permanent magnets and is fitted to the rotor body, and applies a pressure force in a radially inward direction to the plurality of permanent magnets; A method for manufacturing a rotor having the following features: The sleeve includes at least two or more sleeve layers stacked in a radial direction, The plurality of sleeve layers include a first sleeve layer disposed radially inwardly of the sleeve and fitted to the outer circumferential portion of the rotor body; A second sleeve layer is disposed radially outward of the first sleeve layer and fitted to the first sleeve layer; having The manufacturing method includes: a first fitting step of press-fitting the outer circumferential portion of the rotor body into the first sleeve layer having a first inner diameter smaller than an outer diameter of the outer circumferential portion of the rotor body; a second fitting step of press-fitting a first outer circumferential portion of the first sleeve layer fitted to the outer circumferential portion of the rotor body into the second sleeve layer having a second inner diameter smaller than a first outer diameter of the first sleeve layer; A method for manufacturing a rotor comprising the steps of:

2. 2. The method of claim 1, further comprising the steps of: the plurality of sleeve layers include a third sleeve layer disposed radially outward of the second sleeve layer and fitted to a second outer circumferential portion of the second sleeve layer; A method for manufacturing a rotor, comprising a third fitting process for pressing and fitting the second outer circumferential portion of the second sleeve layer fitted into the first sleeve layer into the third sleeve layer having a third inner diameter smaller than the second outer diameter of the second sleeve layer.

3. 2. The method of claim 1, further comprising the steps of: The method for manufacturing a rotor, wherein the plurality of sleeve layers are formed of carbon fiber reinforced plastic (CFRP).

4. A rotor core; A plurality of permanent magnets are provided on an outer periphery of the rotor core and arranged in parallel in a circumferential direction of the rotor core; a cylindrical sleeve that surrounds an outer periphery of a rotor body including the rotor core and the plurality of permanent magnets and is fitted to the rotor body, and applies a pressure force in a radially inward direction to the plurality of permanent magnets; A rotor having The sleeve includes at least two or more sleeve layers stacked in a radial direction, The plurality of sleeve layers include a first sleeve layer disposed radially inwardly of the sleeve and fitted to the outer circumferential portion of the rotor body; A second sleeve layer is disposed radially outward of the first sleeve layer and fitted to the first sleeve layer; A rotor having

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