Rotor and method for manufacturing rotor

Abstract

A rotor according to the present invention is for a rotating electric machine. The rotor comprises: a shaft; a base disposed so as to surround the outer peripheral surface of a mounting portion provided to the shaft; and a plurality of magnets disposed side by side in the circumferential direction of the rotor on the outer peripheral surface of the base. The rotor comprises a resin ring member having filaments wound so as to surround the outer peripheral surfaces of the magnets. The outer diameter of the mounting portion increases from one side in the axial direction toward the other side in the axial direction of the shaft. The inner diameter of the base increases from one side in the axial direction toward the other side in the axial direction.

Description

Rotor and method for manufacturing the same

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

[0002] JP2003-111323A discloses a rotor for a generator motor. A permanent magnet is disposed on the outer circumferential surface of a shaft that constitutes the rotor. A filament winding layer is laminated on the outer circumferential surface of the permanent magnet.

[0003] The filament winding layer is formed by winding a roving made up of multiple filaments around a permanent magnet and hardening it.

[0004] In order to prevent the permanent magnets from floating up during high-speed rotation of such a rotor, it is necessary to apply a large tension to the roving while winding it around the rotor. However, if the tension applied to the roving is large, the force is concentrated on a single filament that makes up the roving, which may cause the filament to break.

[0005] For this reason, it is necessary to increase the thickness of the filament winding layer by winding the roving in layers while suppressing the winding tension, thereby increasing the holding force of the permanent magnet.

[0006] The present invention has been made in consideration of such problems, and aims to provide a rotor and a method for manufacturing a rotor that can increase the holding force of the magnet while suppressing filament breakage.

[0007] According to one aspect of the present invention, a rotor for an electric motor includes a shaft, a base arranged to surround the outer circumferential surface of a mounting portion provided on the shaft, and a plurality of magnets arranged in a circumferential direction of the rotor on the outer circumferential surface of the base. The rotor includes a resin ring member having filaments wound around the outer circumferential surfaces of the magnets. The outer diameter of the mounting portion increases from one axial side to the other axial side of the shaft. The inner diameter of the base increases from one axial side to the other axial side.

[0008] Fig. 1 is a cross-sectional view showing a rotor according to this embodiment. Fig. 2 is a cross-sectional view taken along line II-II in Fig. 1. Fig. 3 is a cross-sectional view showing a divided member provided with a magnet. Fig. 4 is an explanatory diagram showing a method for manufacturing a rotor according to this embodiment.

[0009] Hereinafter, an embodiment of the present invention will be described with reference to the drawings etc. First, a rotor 10 will be described.

[0010] Fig. 1 is a cross-sectional view showing a rotor 10 according to this embodiment. Fig. 2 is a cross-sectional view taken along line II-II in Fig. 1. Fig. 3 is a cross-sectional view showing divided members (110, 112, 114, 116, 118, 120) provided with magnets 28.

[0011] As shown in Figures 1 and 2, a rotor 10 according to this embodiment constitutes a rotating portion of a rotating electric machine 12. The rotating electric machine 12 is used, for example, in an electric vehicle. The rotating electric machine 12 functions as an SPM type electric motor that supplies driving force during running. The rotating electric machine 12 also functions as a generator during regenerative braking.

[0012] Rotor 10 includes a shaft 20, a base 24 arranged so as to surround the outer circumferential surface of a mounting portion 22 provided on shaft 20, and a plurality of magnets 28 arranged side by side on the outer circumferential surface of base 24 in a circumferential direction 26 (see FIG. 2 ) of rotor 10. Rotor 10 also includes a resin ring member 32 having filaments 30 wound around the outer circumferential surfaces of magnets 28.

[0013] (Shaft) The shaft 20 is made of metal. The shaft 20 has a cylindrical shaft portion 40. The aforementioned mounting portion 22 is integrally provided on the shaft portion 40 by a large-diameter portion formed on the shaft portion 40. A mounting portion outer diameter 44, which indicates the outer diameter of the portion of the mounting portion 22 to which the pedestal 24 is attached, increases from a mounting portion one end face 22A on one axial side 46 of the shaft 20 to a mounting portion other end face 22B on the other axial side 50. As a result, the outer peripheral surface of the portion of the mounting portion 22 to which the pedestal 24 is attached is inclined with respect to the central axis C of the shaft 20.

[0014] A threaded portion 62 having threads 60 formed on the circumferential surface is provided on the shaft portion 40 on one axial side 46 of the mounting portion 22. The threaded portion 62 has a larger diameter than the shaft portion 40 and a smaller diameter than the mounting portion 22. The threaded portion 62 is integrally formed with the shaft portion 40 and the mounting portion 22.

[0015] The shaft 20 is provided with a first flange portion 72 that is provided at a portion of the mounting portion 22 near the end on the other axial side 50 and has a diameter larger than a base inner diameter 70 that serves as the inner diameter of the base 24. The first flange portion 72 is integrally formed with the edge of the mounting portion 22 on the other axial side 50. The first flange portion 72 is formed around the entire circumference of the mounting portion 22. The first flange portion 72 that protrudes from the mounting portion 22 has a height that allows it to abut against the base other end surface 24B of the base 24 and the magnet other end surface 28B of the magnet 28.

[0016] The shaft 20 also includes a second flange portion 76 that is disposed closer to the end of the one axial side 46 than the mounting portion 22 and has a diameter larger than the base inner diameter 70 that serves as the inner diameter of the base 24. The second flange portion 76 is configured as a nut that is threaded onto the threaded portion 62 provided on the shaft 20.

[0017] Specifically, the second flange portion 76 is formed in the shape of a ring plate. A screw groove 76A that screws onto the threads 60 of the screw portion 62 is formed on the inner peripheral surface of the second flange portion 76. The second flange portion 76 has a size that allows it to abut against a base end face 24A, which is the end face of one axial side 46 of the base 24, and a magnet end face 28A, which is the end face of one axial side 46 of the magnet 28, when screwed onto the screw portion 62 of the shaft 20.

[0018] A plurality of notches 76B are formed in the outer edge of the second flange portion 76. The notches 76B have a depth that allows portions of the magnet one end surface 28A of the magnet 28 and the base one end surface 24A of the base 24 to be exposed when the second flange portion 76 is threaded onto the thread portion 62. When the second flange portion 76 is threaded onto the thread portion 62, the general portion 76C of the second flange portion 76 can abut against the magnet one end surface 28A and the base one end surface 24A, and the notches 76B can expose portions of the magnet one end surface 28A and the base one end surface 24A.

[0019] As a result, second flange portion 76 functions as a stopper that restricts movement of base 24 in axial direction 78 while abutting against the axial end surface of base 24. Furthermore, in a state in which movement of base 24 in axial direction 78 is restricted, first flange portion 72 and second flange portion 76 abut against the end surfaces of base 24 and magnet 28 in axial direction 78.

[0020] In this embodiment, the first flange portion 72 and the second flange portion 76 are described as contacting the end surfaces of the base 24 and the magnet 28 in the axial direction 78, but this embodiment is not limited to this structure. The first flange portion 72 and the second flange portion 76 may contact only the end surfaces of the base 24.

[0021] In this embodiment, the second flange portion 76 is configured by a nut, but the second flange portion 76 is not limited to a nut.

[0022] The second flange portion 76 may be configured, for example, by a ring-shaped member having a press-fit hole into which the shaft 20 can be press-fitted. In this case, by press-fitting the shaft 20 into the press-fit hole of the ring-shaped member to fix the ring-shaped member, it becomes possible to restrict movement of the base 24 in the axial direction 78 by the ring-shaped member.

[0023] 2, the mounting portion 22 has a hexagonal cross section. The outer peripheral surface of the mounting portion 22 is formed with a first flat surface 82 having a first recess 80, a second flat surface 86 having a second recess 84, and a third flat surface 90 having a third recess 88. The outer peripheral surface of the mounting portion 22 is also formed with a fourth flat surface 94 having a fourth recess 92, a fifth flat surface 98 having a fifth recess 96, and a sixth flat surface 102 having a sixth recess 100.

[0024] The bottom surfaces of the recesses 80, 84, 88, 92, 96, and 100 formed in the flat portions 82, 86, 90, 94, 98, and 102 are planes that are substantially parallel to the flat portions 82, 86, 90, 94, 98, and 102.

[0025] Each recess 80, 84, 88, 92, 96, 100 formed in each flat portion 82, 86, 90, 94, 98, 102 is disposed at the circumferential center of the flat portion 82, 86, 90, 94, 98, 102. Each recess 80, 84, 88, 92, 96, 100 formed in each flat portion 82, 86, 90, 94, 98, 102 extends over the entire area in the axial direction 78 of the flat portion 82, 86, 90, 94, 98, 102. Both inner surfaces of each recess 80, 84, 88, 92, 96, 100 extend approximately parallel to each other, and the width between the opposing inner surfaces is constant over the entire length.

[0026] 1 , the seat inner diameter 70, which is the inner diameter of the seat 24, increases from the seat one end face 24A on the one axial side 46 to the seat other end face 24B on the other axial side 50. As a result, the inner circumferential surface of the seat 24 is inclined with respect to the central axis C of the shaft 20. Furthermore, the outer circumferential surface of the seat 24 extends substantially parallel to the central axis C of the shaft 20. The seat 24 can be made of synthetic resin or metal. Examples of metals that form the seat 24 include stainless steel and aluminum.

[0027] 2 , the base 24 is composed of a plurality of divided members (110, 112, 114, 116, 118, 120) divided in the circumferential direction 26. The base inner diameter 70 of the base 24 can be increased by expanding the adjacent divided members (110, 112, 114, 116, 118, 120) in the circumferential direction 26.

[0028] Although the present embodiment describes an example in which the base 24 is configured from a plurality of divided members (110, 112, 114, 116, 118, 120), the base 24 may also be configured from a single cylindrical member. In this case, the cylindrical base 24 can be formed from a metal material or the like that allows the base inner diameter 70 to expand along the mounting portion 22 by being press-fitted into the mounting portion 22, whose mounting portion outer diameter 44 increases from one axial side 46 to the other axial side 50.

[0029] A first divided member 110, which is a divided member constituting the base 24, is disposed along the first flat surface 82 of the mounting portion 22. A second divided member 112 is disposed along the second flat surface 86. A third divided member 114 is disposed along the third flat surface 90. A fourth divided member 116 is disposed along the fourth flat surface 94. A fifth divided member 118 is disposed along the fifth flat surface 98. A sixth divided member 120 is disposed along the sixth flat surface 102.

[0030] First divided member 110 has a first opposing surface 110A facing first flat portion 82 and a first convex portion 110B that can fit into first recess 80. Second divided member 112 has a second opposing surface 112A facing second flat portion 86 and a second convex portion 112B that can fit into second recess 84. Third divided member 114 has a third opposing surface 114A facing third flat portion 90 and a third convex portion 114B that can fit into third recess 88.

[0031] The fourth divided member 116 has a fourth opposing surface 116A facing the fourth flat portion 94 and a fourth convex portion 116B that can fit into the fourth recess 92. The fifth divided member 118 has a fifth opposing surface 118A facing the fifth flat portion 98 and a fifth convex portion 118B that can fit into the fifth recess 96. The sixth divided member 120 has a sixth opposing surface 120A facing the sixth flat portion 102 and a sixth convex portion 120B that can fit into the sixth recess 100.

[0032] As a result, a recessed and protruding shape that fits with each other is formed on the outer peripheral surface of the mounting portion 22 and the opposing surfaces 110A, 112A, 114A, 116A, 118A, and 120A of the divided members 110, 112, 114, 116, 118, and 120 that face the outer peripheral surface of the mounting portion 22. The recessed and protruding shapes are formed by the protruding portions 110B, 112B, 114B, 116B, 118B, and 120B and the recessed portions 80, 84, 88, 92, 96, and 100.

[0033] Each of the opposing surfaces 110A, 112A, 114A, 116A, 118A, and 120A is formed as a flat surface. The end faces of the respective convex portions 110B, 112B, 114B, 116B, 118B, and 120B protruding from each of the opposing surfaces 110A, 112A, 114A, 116A, 118A, and 120A are formed as flat surfaces that are substantially parallel to the corresponding opposing surfaces 110A, 112A, 114A, 116A, 118A, and 120A.

[0034] Each of the protrusions 110B, 112B, 114B, 116B, 118B, and 120B protruding from each of the opposing surfaces 110A, 112A, 114A, 116A, 118A, and 120A is disposed at the circumferential center of the corresponding opposing surface 110A, 112A, 114A, 116A, 118A, and 120A. Each of the protrusions 110B, 112B, 114B, 116B, 118B, and 120B protruding from each of the opposing surfaces 110A, 112A, 114A, 116A, 118A, and 120A extends over the entire axial direction 78 of the corresponding opposing surface 110A, 112A, 114A, 116A, 118A, and 120A.

[0035] Furthermore, both outer surfaces of each of the protrusions 110B, 112B, 114B, 116B, 118B, and 120B extend substantially parallel to one another, and the width between the outer surfaces is constant over the entire length.

[0036] As a result, each of the divided members 110, 112, 114, 116, 118, and 120 constituting the base 24 is permitted to move in the axial direction 78 of the shaft 20 with each of the convex portions 110B, 112B, 114B, 116B, 118B, and 120B fitted into each of the concave portions 80, 84, 88, 92, 96, and 100 of the mounting portion 22. Furthermore, each of the divided members 110, 112, 114, 116, 118, and 120 is restricted from moving in the circumferential direction 26 of the rotor 10.

[0037] As shown in FIG. 3 (showing the first divided member 110 as a representative), each divided member 110, 112, 114, 116, 118, 120 has an outer surface 130 on the radially outer side of the rotor 10, which is composed of a lower stage portion 130A and a higher stage portion 130B.

[0038] The low step portion 130A and the high step portion 130B are configured with a plane extending in the axial direction 78. The high step portion 130B is located radially outward of the low step portion 130A. A step portion 132 is formed between the low step portion 130A and the high step portion 130B.

[0039] (Magnet) The magnet 28 arranged on the base 24 is composed of a first magnet portion 28C arranged on the lower stage portion 130A of each of the divided members 110, 112, 114, 116, 118, and 120, and a second magnet portion 28D arranged on the upper stage portion 130B.

[0040] The first magnet portion 28C has approximately the same length as the low stage portion 130A and approximately the same width as the low stage portion 130A. The first magnet portion 28C has a first inner surface 28C-1 that is arranged radially inward and that is configured as a curved surface. The first magnet portion 28C has a first outer surface 28C-2 that is arranged radially outward and that is configured as a curved surface. The first magnet portion 28C is positioned with the first inner surface 28C-1 abutting against the low stage portion 130A and with its side surface abutting against the step portion 132.

[0041] The second magnet portion 28D has approximately the same length as the high stage portion 130B and approximately the same width as the high stage portion 130B. The second magnet portion 28D has a second inner surface 28D-1 arranged on the radially inner side that is configured as a curved surface. The second magnet portion 28D has a second outer surface 28D-2 arranged on the radially outer side that is configured as a curved surface. The second magnet portion 28D is positioned with the second inner surface 28D-1 arranged in contact with the high stage portion 130B and with its side surface in contact with the side surface of the first magnet portion 28C arranged in the low stage portion 130A.

[0042] The first magnet portion 28C is formed to be thicker than the second magnet portion 28D. The difference in thickness between the first magnet portion 28C and the second magnet portion 28D is set to a value that prevents a step from occurring between the first outer surface 28C-2 of the first magnet portion 28C arranged in the low stage portion 130A and the second outer surface 28D-2 of the second magnet portion 28D arranged in the high stage portion 130B.

[0043] Each magnet portion 28C, 28D is composed of a permanent magnet. The polarity of the first outer surface 28C-2 side of the first magnet portion 28C is different from the polarity of the second outer surface 28D-2 side of the second magnet portion 28D. By adjusting the polarity of each magnet portion 28C, 28D attached to each divided member 110, 112, 114, 116, 118, 120 of the base 24, a Halbach array magnetic circuit can be configured.

[0044] (Ring Member) As shown in FIGS. 1 and 2, the ring member 32 is formed in a cylindrical shape that surrounds the magnet 28 provided on the base 24.

[0045] The ring member 32 completely surrounds each magnet 28. The ring member 32 has a length that covers the entire area of ​​each magnet 28 in the axial direction 78.

[0046] The ring member 32 is made of synthetic resin. Inside the synthetic resin, a plurality of filaments 30 are arranged, each wound around the magnet 28. Each filament 30 is fixed by the synthetic resin.

[0047] The filaments 30 are made of carbon fiber, which has a small coefficient of linear expansion and is not easily affected by temperature. The ring member 32 having the filaments 30 is made of CFRP (Carbon Fiber Reinforced Plastics), which is a reinforced plastic.

[0048] (Method of Manufacturing Rotor) Next, a method of manufacturing the rotor 10 according to this embodiment will be described with reference to the drawings. Fig. 4 is an explanatory diagram showing the method of manufacturing the rotor 10 according to this embodiment.

[0049] As shown in FIG. 4, the manufacturing process 200 of the manufacturing method for the rotor 10 according to this embodiment includes an insertion state forming process S10, a winding process S12, a hardening process S14, a relative movement process S16, and a movement restriction process S18.

[0050] (Insertion state forming process) In the insertion state forming process S10, the worker forms a state in which the mounting portion 22 of the shaft 20 is inserted into the base 24 on whose outer surface the magnet 28 is arranged, with the direction in which the mounting portion outer diameter 44 of the mounting portion 22 increases and the direction in which the base inner diameter 70 of the base 24 increases being the same.

[0051] Specifically, the worker temporarily attaches the first inner surface 28C-1 of the first magnet portion 28C to the lower stage portion 130A of each of the divided members 110, 112, 114, 116, 118, and 120 that make up the base 24 with an adhesive or the like (see FIG. 3). The worker also temporarily attaches the second inner surface 28D-1 of the second magnet portion 28D to the upper stage portion 130B of each of the divided members 110, 112, 114, 116, 118, and 120 with an adhesive or the like (see FIG. 3). The worker then combines the divided members 110, 112, 114, 116, 118, and 120 to form the cylindrical base 24 (see FIG. 2).

[0052] Next, the worker inserts the end of one axial side 46 of the shaft 20 from the other axial side 50 of the base 24, and positions the mounting portion 22 inside the base 24. In this way, the worker creates a state in which the mounting portion outer diameter 44 of the mounting portion 22 increases in the same direction as the base inner diameter 70 of the base 24 increases, and the mounting portion 22 of the shaft 20 is inserted into the base 24, on whose outer peripheral surface the magnet 28 is arranged.

[0053] Then, the worker screws the second flange portion 76 into the threaded portion 62 of the shaft 20 to temporarily fasten the second flange portion 76 to the shaft 20 .

[0054] In the insertion state forming step S10, the magnets 28 are provided to each of the divided members 110, 112, 114, 116, 118, and 120, and then the divided members 110, 112, 114, 116, 118, and 120 are combined to form the cylindrical base 24, and the attachment portion 22 is inserted into the base 24. However, the insertion state forming step S10 is not limited to this. For example, in the insertion state forming step S10, the magnets 28 may be provided to the base 24 after the divided members 110, 112, 114, 116, 118, and 120 are set in the attachment portion 22 to form the base 24.

[0055] (Winding process) In the winding process S12, the worker winds the molding material 204 having the filament 30 (see Figures 1 and 2) around the outer peripheral surface of the magnet 28 while forming a gap 202 between the first flange portion 72 and the base 24.

[0056] An example of the molding material 204 is a material in which a plurality of filaments 30 made of carbon fiber are impregnated with a thermosetting resin.

[0057] Specifically, the worker tightly wraps the molding material 204 around the magnet 28 from the end of the one axial side 46 to the end of the other axial side 50. As a result, the outer circumferential surface of the magnet 28 is covered with a layer of the wrapped molding material 204.

[0058] Here, the mounting portion 22 of the shaft 20 is disposed inside each of the divided members 110, 112, 114, 116, 118, and 120 of the base 24 around which the molding material 204 is wound. Therefore, it is possible to perform the winding operation of the molding material 204 without providing a temporary holding jig inside the base 24.

[0059] (Curing Step) In the curing step S14 , the worker cures the molding material 204 to form the ring member 32 .

[0060] Specifically, the worker applies heat to the molding material 204 wound around the magnet 28 to harden the thermosetting resin impregnated in the filaments 30 of the molding material 204. As a result, each filament 30 is fixed by the hardened synthetic resin while wound around the magnet 28. As a result, the outer circumferential surface of the magnet 28 is surrounded by the ring member 32 made of synthetic resin and having the filaments 30.

[0061] (Relative Movement Step) In the relative movement step S16, after the hardening step S14, the worker relatively moves the base 24 and the shaft 20 in the axial direction 78 so that the first flange portion 72 and the end face of the base 24 abut against each other.

[0062] Specifically, the worker inserts the pressing portion 210A provided on the jig 210 into the notch 76B of the second flange portion 76. Then, the worker abuts the pressing portion 210A against the first base end surface 24A of the base 24, the first magnet end surface 28A of the magnet 28, and the first ring member end surface 32A of the ring member 32 (see FIG. 1). In this state, the worker moves the jig 210 toward the first flange portion 72 until the other base end surface 24B of the base 24 and the other magnet end surface 28B of the magnet 28 abut against the first flange portion 72 of the mounting portion 22 (see FIG. 1).

[0063] Here, the mounting portion outer diameter 44 of the mounting portion 22 of the shaft 20 increases from one axial side 46 to the other axial side 50. Furthermore, the base inner diameter 70 of the pedestal 24 surrounding the mounting portion 22 increases from one axial side 46 to the other axial side 50. The inner peripheral surface of the pedestal 24 slides against the outer peripheral surface of the mounting portion 22 while moving from the one axial side 46 to the other axial side 50.

[0064] Therefore, as the base 24 moves toward the other axial side 50, the adjacent divided members 110, 112, 114, 116, 118, and 120 are displaced in directions away from each other, increasing the base inner diameter 70. Accordingly, the diameter of the ring member 32 surrounding the base 24 increases.

[0065] Here, the flat surfaces (82, 86, 90, 94, 98, 102, 110A, 112A, 114A, 116A, 118A, 120A) of the base 24 and the mounting portion 22 are in surface contact with each other. Therefore, compared to when the inner peripheral surface of the base 24 and the outer peripheral surface of the mounting portion 22, which are configured with curved surfaces, are in surface contact with each other, the base 24 and the mounting portion 22 can maintain a state of surface contact even if the base inner diameter 70 is larger.

[0066] Furthermore, relative movement between the base 24 and the mounting portion 22 in the axial direction 78 is easier compared to when the inner surface of the base 24 and the outer surface of the mounting portion 22, which are in contact with each other, are configured as curved surfaces whose curvature changes as they move toward the axial direction 78.

[0067] As a result, the worker brings the first flange portion 72 into contact with the end face of the base 24 , and then removes the jig 210 from the rotor 10 .

[0068] (Movement Restricting Step) In the movement restricting step S18 , the worker abuts the second flange portion 76 provided on the shaft 20 against the end face of the base 24 to restrict movement of the base 24 in the axial direction 78 .

[0069] Specifically, the worker tightens second flange portion 76 provided on thread portion 62 of shaft 20 until second flange portion 76 abuts against one base end surface 24A of base 24 and one magnet end surface 28A of magnet 28 (see FIG. 1 ). As a result, base 24 and magnet 28 are sandwiched between first flange portion 72 and second flange portion 76 in the axial direction 78, and movement in the axial direction 78 is restricted, and rotor 10 is formed.

[0070] (Operations and Effects) As described above, the rotor 10 of this embodiment is a rotor 10 for a rotating electric machine 12. The rotor 10 includes a shaft 20, a base 24 arranged to surround the outer circumferential surface of a mounting portion 22 provided on the shaft 20, and a plurality of magnets 28 arranged side by side in a circumferential direction 26 of the rotor 10 on the outer circumferential surface of the base 24. The rotor 10 includes a resin ring member 32 having a filament 30 wound around the outer circumferential surface of the magnet 28. An attachment portion outer diameter 44, which is the outer diameter of the mounting portion 22, increases from one axial side 46 to the other axial side 50 of the shaft 20. A base inner diameter 70, which is the inner diameter of the base 24, increases from one axial side 46 to the other axial side 50.

[0071] In this configuration, the rotor 10 can expand the diameter of the ring member 32 surrounding the base 24 and the magnets 28 by moving the shaft 20 and the base 24 relative to each other while the magnets 28 of the base 24 are surrounded by the ring member 32. This allows the rotor 10 to apply uniform tension to all of the multiple filaments 30 integrated with the ring member 32.

[0072] Therefore, compared to the case where a large tension may be concentrated on a single filament 30 when winding the filament 30 while applying tension, the rotor 10 is able to increase the holding force of the magnet 28 while suppressing breakage of the filament 30.

[0073] This makes it possible to prevent the magnets 28 from unexpectedly floating up even when the rotor 10 is a rotor 10 of an electric motor that rotates at high speed.

[0074] Furthermore, since the rotor 10 can increase the holding force of the magnet 28, it is possible to reduce the outer diameter of the rotor 10 and make it lighter compared to when the ring member 32 is made thicker to increase the holding force.

[0075] In this embodiment, the base 24 is composed of a plurality of divided members ( 110 , 112 , 114 , 116 , 118 , 120 ) divided in the circumferential direction 26 .

[0076] In this configuration, the rotor 10 can have the base inner diameter 70 greatly enlarged compared to when the base 24 is configured from a cylindrical member.

[0077] Furthermore, compared to when the base 24 is made of a cylindrical member, the rotor 10 can reduce the movement force of the shaft 20 or the base 24 required to expand the diameter of the base 24. This allows the rotor 10 to have a smaller drive source that moves the shaft 20 and the base 24 relative to each other, for example.

[0078] In addition, in this embodiment, the outer peripheral surface of the mounting portion 22 and the opposing surfaces (110A, 112A, 114A, 116A, 118A, 120A) of the divided members (110, 112, 114, 116, 118, 120) that face the outer peripheral surface are formed with recessed and protruding shapes (110B, 112B, 114B, 116B, 118B, 120B, 80, 84, 88, 92, 96, 100) that fit into each other.

[0079] In this configuration, the divided members (110, 112, 114, 116, 118, 120) of the base 24 having the magnet 28 are prevented from moving in the circumferential direction 26 relative to the mounting portion 22 of the shaft 20 by the uneven shape.

[0080] This makes it possible to suppress misalignment of the shaft 20 and the base 24 in the circumferential direction 26, even when the torque generated is high, compared to when slippage in the circumferential direction 26 may occur between the mounting portion 22 and the base 24.

[0081] Furthermore, since it is possible to suppress misalignment of the shaft 20 and the base 24 in the circumferential direction 26, it is possible to increase the transmission efficiency of the driving force received by the magnet 28.

[0082] In the present embodiment, the shaft 20 is provided with a first flange portion 72 that is provided at a portion of the attachment portion 22 closer to the end portion of the other axial side 50, and that has a larger diameter than a seat inner diameter 70 that serves as the inner diameter of the seat 24. The shaft 20 is disposed at a portion closer to the end portion of the one axial side 46 than the attachment portion 22, and that has a larger diameter than the seat inner diameter 70 of the seat 24. The second flange portion 76 functions as a stopper that restricts movement of the seat 24 in an axial direction 78 while abutting against the axial end face of the seat 24.

[0083] In this configuration, the base 24, which is disposed so as to surround the mounting portion 22 of the shaft 20, is restricted from moving in the axial direction 78 by the first flange portion 72 and the second flange portion 76. Furthermore, the magnet 28 and the ring member 32 provided on the base 24 are restricted from moving in the axial direction 78 together with the base 24.

[0084] This makes it possible for the rotor 10 to hold the base 24 , the magnet 28 , and the ring member 32 in a state where they are positioned between the first flange portion 72 and the second flange portion 76 .

[0085] In this embodiment, the first flange portion 72 and the second flange portion 76 abut against the end surfaces of the base 24 and the magnet 28 in the axial direction 78 .

[0086] In this configuration, the first flange portion 72 and the second flange portion 76 abut against the end faces of the base 24 and the magnet 28 in the axial direction 78, making it possible to prevent the magnet 28 from shifting in the axial direction 78 without providing a separate structure to prevent the magnet 28 from shifting in position.

[0087] In this embodiment, the second flange portion 76 is a nut that is screwed onto the threaded portion 62 provided on the shaft 20 .

[0088] In this configuration, by screwing the second flange portion 76 formed of a nut onto the threaded portion 62 of the shaft 20 , it is possible to suppress movement of the base 24 and the magnet 28 in the axial direction 78 .

[0089] The manufacturing method of the rotor 10 of this embodiment is a manufacturing method for manufacturing the rotor 10 described above. The manufacturing method of the rotor 10 includes an insertion state forming step S10 in which the mounting portion 22 of the shaft 20 is inserted into the base 24, on the outer peripheral surface of which the magnets 28 are arranged, with the direction in which the mounting portion outer diameter 44 (the outer diameter of the mounting portion 22) increases and the direction in which the base inner diameter 70 (the inner diameter of the base 24) increases, being the same. The manufacturing method of the rotor 10 includes a winding step S12 in which a molding material 204 having filaments 30 is wound around the outer peripheral surface of the magnets 28, with a gap 202 formed between the first flange portion 72 and the base 24. The manufacturing method of the rotor 10 includes a curing step S14 in which the molding material 204 is cured to form the ring member 32. The manufacturing method of the rotor 10 includes a relative movement step S16 in which, after the curing step S14, the base 24 and the shaft 20 are moved relatively in the axial direction 78 so that the first flange portion 72 and the end face of the base 24 abut. The manufacturing method of the rotor 10 includes a movement restricting step S18 of abutting a second flange portion 76 provided on the shaft 20 against an end face of the base 24 to restrict movement of the base 24 in the axial direction 78.

[0090] In this manufacturing method of the rotor 10, the molding material 204 is wound in a state in which a gap 202 is formed between the first flange portion 72 and the base 24, and the molding material 204 is hardened to form the ring member 32. In the manufacturing method of the rotor 10, the base 24 and the shaft 20 are moved relative to each other to expand the diameter of the ring member 32 together with the base 24. As a result, tension is applied uniformly to the multiple filaments 30 integrated with the ring member 32.

[0091] Therefore, compared to the case where a large tension may be concentrated on a single filament 30 when winding the filament 30 while applying tension, the manufacturing method of the rotor 10 makes it possible to increase the holding force of the magnet 28 while suppressing breakage of the filament 30.

[0092] In the manufacturing method of rotor 10, second flange portion 76 provided on shaft 20 is brought into contact with the end face of base 24 to restrict movement of base 24 in axial direction 78. In this way, base 24, magnet 28, and ring member 32 are held by shaft 20, and rotor 10 is formed.

[0093] Although the embodiments of the present invention have been described above, the above embodiments merely illustrate some of the application examples of the present invention, and it is not intended that the technical scope of the present invention be limited to the specific configurations of the above embodiments.

[0094] Although the above-described embodiment has been described using the rotor 10 of the rotating electric machine 12 mounted on an electric vehicle as an example, the use of the rotor 10 is not limited to this. The rotor 10 can be used for other rotating electric machines 12.

Claims

1. A rotor for a rotating electric machine comprising: a shaft; a base arranged to surround the outer peripheral surface of a mounting portion provided on the shaft; a plurality of magnets arranged in a row circumferentially of the rotor on the outer peripheral surface of the base; and a resin ring member having filaments wound around the outer peripheral surfaces of the magnets, wherein the outer diameter of the mounting portion increases from one axial side to the other axial side of the shaft, and the inner diameter of the base increases from one axial side to the other axial side.

2. A rotor according to claim 1, wherein the base is composed of a plurality of divided members divided in the circumferential direction.

3. A rotor according to claim 2, wherein the outer peripheral surface of the mounting portion and the opposing surface of the divided member that faces the outer peripheral surface are formed with recessed and protruding shapes that fit together.

4. A rotor as claimed in claim 3, wherein the shaft comprises: a first flange portion provided at a location of the mounting portion closer to the end on the other axial side, the first flange portion having a diameter larger than the inner diameter of the base; and a second flange portion located at a location closer to the end on one axial side than the mounting portion, the second flange portion having a diameter larger than the inner diameter of the base, the second flange portion functioning as a stopper that restricts axial movement of the base when in contact with the axial end face of the base.

5. A rotor according to claim 4, wherein the first flange portion and the second flange portion abut against the axial end faces of the base and the magnet.

6. A rotor according to claim 4, wherein the second flange portion is a nut that is screwed onto a threaded portion provided on the shaft.

7. A method of manufacturing a rotor for manufacturing the rotor described in any one of claims 4 to 6, comprising: an insertion state forming step of forming a state in which the mounting portion of the shaft is inserted into the base having the magnet disposed on its outer peripheral surface, with the direction in which the outer diameter of the mounting portion increases and the direction in which the inner diameter of the base increases being the same; a winding step of winding a molding material having the filaments around the outer peripheral surface of the magnet, with a gap formed between the first flange portion and the base; a hardening step of hardening the molding material to form the ring member; a relative movement step of moving the base and the shaft relatively in the axial direction after the hardening step so that the first flange portion abuts against the end face of the base; and a movement restriction step of abutting the second flange portion provided on the shaft against the end face of the base to restrict movement of the base in the axial direction.

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