Axial gap motor

Abstract

An axial gap motor (10) comprises: a stator (14); and a rotor (12) facing the stator with a gap (13) interposed therebetween in the axial direction of the stator. The gap is provided with support parts (70, 70A, 70B, 82, 100, 100A, 100B) for supporting the rotor with respect to the stator. The support parts are annular support members (70, 70A, 70B) formed in an annular shape around the axial direction, are held by an annular holding member (84) formed in an annular shape around the axial direction, or are formed integrally with the stator and / or the rotor.

Description

Axial gap motor Cross-reference to Related Applications

[0001] This application is based on Japanese Patent Application No. 2025-057116 filed on March 28, 2025, and claims the benefit of priority therefrom. The entire content of said patent application is incorporated herein by reference.

[0002] The technology of the present disclosure relates to an axial gap motor.

[0003] Generally, an axial gap motor includes a stator and a rotor facing the stator with a gap interposed therebetween in the axial direction of the stator. In such an axial gap motor, it is required to stably maintain the gap while minimizing the gap. As a technique for maintaining the gap between the stator and the rotor, a technique has been proposed in which a plurality of grooves are provided on mutually opposing surfaces of the stator and the rotor, and a plurality of balls are respectively disposed in the plurality of grooves (see, for example, Japanese Patent No. 7064702).

[0004] As a result of detailed studies by the inventor, the following problems have been found. That is, when assembling or disassembling an axial gap motor, easy work is required. However, in the technique of maintaining the gap between the stator and the rotor by providing a plurality of grooves on the mutually opposing surfaces of the stator and the rotor and disposing a plurality of balls in the plurality of grooves respectively, the plurality of balls become scattered when assembling or disassembling the axial gap motor, so it cannot be said that the assembling or disassembling work is easy.

[0005] The technology of the present disclosure provides an axial gap motor that can maintain the gap between the stator and the rotor while facilitating work during assembly or disassembly.

[0006] An axial gap motor according to the technology of the present disclosure comprises a stator and a rotor facing the stator via a gap in the axial direction of the stator, wherein the gap is provided with a support portion that supports the rotor relative to the stator, and the support portion is an annular support member formed in an annular shape around the axial direction, or is held by an annular holding member formed in an annular shape around the axial direction, or is integrally formed with at least one of the stator and the rotor.

[0007] The technology of this disclosure provides an axial gap motor that can maintain the gap between the stator and the rotor while facilitating assembly or disassembly.

[0008] This is a perspective view showing a part of the motor cut off. This is a perspective view showing the motor disassembled. This is a schematic cross-sectional view showing a cross-section of the motor cut along the axial and radial directions. This is a perspective view showing the core, first magnet, inner annular support member, and outer annular support member disassembled according to the first embodiment. This is a schematic cross-sectional view showing the core, first magnet, inner annular support member, and outer annular support member according to the first embodiment. This is a schematic unfolded view showing the core, first magnet, and inner annular support member according to the first embodiment unfolded in the circumferential direction. This is a schematic unfolded view showing the core, first magnet, and outer annular support member according to the first embodiment unfolded in the circumferential direction. This is a schematic cross-sectional view showing the attractive force from the stator acting on the rotor according to the first embodiment. This is a schematic cross-sectional view showing the core, first magnet, and annular support member according to a modified example of the first embodiment. This is a schematic cross-sectional view showing the core, first magnet, and ball retainer according to the second embodiment. This is a perspective view showing the ball retainer according to the second embodiment disassembled. This is a plan view of the core according to the second embodiment viewed from one side in the axial direction. This is a bottom view of the first magnet according to the second embodiment viewed from the other side in the axial direction. This is a schematic cross-sectional view showing the core, first magnet, and ball retainer according to the first modification of the second embodiment. This is a schematic cross-sectional view showing the core, first magnet, first support member, and ball retainer according to the second modification of the second embodiment. This is a schematic cross-sectional view showing the core, first magnet, first projection, and second projection according to the third embodiment. This is a bottom view of the first magnet according to the third embodiment, viewed from the other axial side. This is a bottom view of the first magnet according to the first modification of the third embodiment, viewed from the other axial side. This is a schematic cross-sectional view showing the core, first magnet, first projection, and projection according to the second modification of the third embodiment. This is a schematic cross-sectional view showing the core, first magnet, first projection, and second projection according to the third modification of the third embodiment. This is a schematic cross-sectional view showing the core, first magnet, first support member, and projection according to the fourth modification of the third embodiment. This is a schematic cross-sectional view showing the core, first magnet, first support member, and projection according to the fifth modification of the third embodiment. This is a schematic cross-sectional view showing the wear progression of the annular support member according to the fourth embodiment.This graph shows an example of the relationship between the current supplied to the motor according to the fourth embodiment and the torque of the motor.

[0009] First, an example of an axial gap motor (hereinafter referred to as "motor 10") will be described with reference to Figures 1 to 3. Motor 10 has a configuration that serves as the basis for the first to third embodiments described later.

[0010] Note that the arrows Z, R, and C shown in Figures 1 to 3 indicate the axial side, radially outward side, and circumferential side of the motor 10, respectively. In the following description, the axial, radial, and circumferential directions of the motor 10 will be referred to as the axial, radial, and circumferential directions, respectively. Furthermore, the axial, radial, and circumferential directions of the rotor 12, stator 14, first frame 21, and second frame 23, which will be described later, are the same directions as the axial, radial, and circumferential directions of the motor 10, respectively.

[0011] The motor 10 comprises a rotor 12, a stator 14, a first frame 21, and a second frame 23. The rotor 12 and the stator 14 face each other in the axial direction with a gap between them. In other words, the motor 10 is an axial gap type motor in which the rotor 12 and the stator 14 face each other in the axial direction with an axial gap between them. Furthermore, the motor 10 is a brushless motor that does not have brushes. Moreover, as will be described later, the motor 10 is a double axial gap type motor in which the stator 14 is positioned between a first magnet 18 and a second magnet 19 that are spaced apart in the axial direction, thereby forming a first axial gap between the first magnet 18 and the stator 14, and a second axial gap between the second magnet 19 and the stator 14.

[0012] For example, the first frame 21 is formed as a frame end, and the second frame 23 is formed as a heat sink. The first frame 21 and the second frame 23 form a case 16 that houses the rotor 12 and the stator 14.

[0013] The stator 14 generates a rotating magnetic field relative to the rotor 12. The rotor 12 rotates due to the rotating magnetic field generated by the stator 14. The first frame 21 and the second frame 23 are spaced apart in the axial direction. The stator 14 is fixed to the first frame 21 and the second frame 23, and the rotor 12 is rotatably supported on both frames.

[0014] The rotor 12 comprises a rotating shaft 22, a first magnet 18, a second magnet 19, a first support member 24, and a second support member 25. The rotating shaft 22 extends in the axial direction. The first magnet 18 is fixed to the rotating shaft 22 via the first support member 24. The second magnet 19 is fixed to the rotating shaft 22 via the second support member 25.

[0015] The first magnet 18 and the first support member 24 form the axial portion of the rotor 12 (hereinafter referred to as the "first rotor portion 12A"), and the second magnet 19 and the second support member 25 form the axial portion of the rotor 12 (hereinafter referred to as the "second rotor portion 12B").

[0016] The first support member 24 and the second support member 25 are formed from a non-magnetic material and are shaped like discs with the axial direction being the thickness direction. However, the first support member 24 and the second support member 25 may also be formed from a magnetic material. The first support member 24 and the second support member 25 are fixed to the rotation shaft 22, spaced apart from each other in the axial direction.

[0017] The first magnet 18 and the second magnet 19 are, for example, ring magnets formed in an annular shape along the circumferential direction. Alternatively, the first magnet 18 and the second magnet 19 may be configured with multiple segment magnets arranged in an annular shape along the circumferential direction. The first magnet 18 is fixed to the other axial side of the first support member 24. The second magnet 19 is fixed to one axial side of the second support member 25. As a result, the first magnet 18 and the second magnet 19 are positioned facing each other in the axial direction.

[0018] The magnetic pole center of the north pole of the first magnet 18 and the magnetic pole center of the south pole of the second magnet 19 are positioned opposite each other in the axial direction and at the same position in the circumferential direction.

[0019] The stator 14 comprises a core 26, a first coil 31, and a second coil 32. The core 26 is positioned between a first magnet 18 and a second magnet 19. The first coil 31 is mounted on one axial side of the core 26, and the second coil 32 is mounted on the other axial side of the core 26. The first coil 31 and the second coil 32 are examples of "coils" according to the technology of this disclosure.

[0020] The core 26 comprises a plurality of tooth portions 26A, an inner flange portion 26B, and an outer flange portion 26C. The plurality of tooth portions 26A are arranged at intervals in the circumferential direction. The plurality of tooth portions 26A form a magnetic flux path between the first magnet 18 and the second magnet 19. The inner flange portion 26B is located radially inward from the plurality of tooth portions 26A and connects the plurality of tooth portions 26A in the circumferential direction. The outer flange portion 26C is located radially outward from the plurality of tooth portions 26A and connects the plurality of tooth portions 26A in the circumferential direction.

[0021] Multiple (for example, 72) tooth portions 26A are set to have the same shape and dimensions. Multiple tooth portions 26A are arranged at equal intervals along the circumferential direction. Multiple tooth portions 26A are formed in a plate shape (in other words, a rectangular block shape) that extends axially with the circumferential direction as the thickness direction. The thickness dimension of the tooth portion 26A gradually increases towards the radially outward direction. Also, the axial dimension of the tooth portion 26A gradually decreases towards the radially outward direction. One axial surface of the tooth portion 26A is formed as a first opposing surface 26D that is positioned axially opposite to the first magnet 18. The other axial surface of the tooth portion 26A is formed as a second opposing surface 26E that is positioned axially opposite to the second magnet 19.

[0022] The inner flange portion 26B is formed in an annular shape, extending circumferentially with the axial direction as the thickness direction. The thickness dimension of the inner flange portion 26B is set to be smaller than the axial dimension of the multiple teeth portions 26A. The inner flange portion 26B connects the axial central portions of the radially inner ends of the multiple teeth portions 26A along the circumferential direction.

[0023] The outer flange portion 26C is formed in an annular shape, extending circumferentially with the axial direction as the thickness direction. The thickness dimension of the outer flange portion 26C is set to be smaller than the axial dimension of the multiple teeth portions 26A. The thickness dimension of the outer flange portion 26C is set to be the same as the thickness dimension of the inner flange portion 26B. Multiple notches 26F are formed on the outer circumference of the outer flange portion 26C. The multiple notches 26F have a shape that is cut out so that the radially outer side is open. For example, 16 notches 26F are formed on the outer circumference of the outer flange portion 26C. The 16 notches 26F are arranged at equal intervals along the circumferential direction. The 16 notches 26F have the function of preventing rotation of the first frame 21 and the second frame 23, which will be described later, and the function of allowing the bolt 50 to pass through in the axial direction.

[0024] The first coil 31 is formed by a plurality of coil layers 54. For example, the first coil 31 has two coil layers 54. The two coil layers 54 are mounted on one axial side of the core 26 in an axially overlapping manner. Similarly, the second coil 32 is formed by a plurality of coil layers 54. For example, the second coil 32 has two coil layers 54. The two coil layers 54 are mounted on the other axial side of the core 26 in an axially overlapping manner.

[0025] Each coil layer 54 has multiple segment conductors 60. Each segment conductor 60 of each coil layer 54 functions as a coil wound around the teeth portion 26A. In each coil layer 54, multiple segment conductors 60 are stacked in two stages in the axial direction. The segment conductors 60 of each coil layer 54 are connected in a predetermined manner. The coil composed of multiple segment conductors 60 is in the form of a distributed winding wound across multiple teeth portion 26A. Alternatively, the coil composed of multiple segment conductors 60 may be in the form of a concentrated winding wound around each tooth portion 26A.

[0026] The first frame 21 comprises a disc portion 21A and a peripheral wall portion 21B. The disc portion 21A is formed in a disc shape with the axial direction as the thickness direction. The disc portion 21A extends radially outward from the center of the first frame 21. The peripheral wall portion 21B is formed on the outer periphery of the disc portion 21A and extends axially in the other direction from the outer periphery of the disc portion 21A.

[0027] The second frame 23 comprises a disc portion 23A and a peripheral wall portion 23B. The disc portion 23A is formed in a disc shape with the axial direction as the thickness direction. The peripheral wall portion 23B is formed on the outer periphery of the disc portion 23A and extends from the outer periphery of the disc portion 23A toward one side in the axial direction.

[0028] Through holes extending axially are formed in the centers of the disc portions 21A and 23A, and bearings 20 are fixed to the inner circumference of each through hole. The rotation axis 22 of the rotor 12 is rotatably supported by each bearing 20.

[0029] Multiple (e.g., eight) insertion holes 21C are formed in the peripheral wall portion 21B of the first frame 21, and multiple (e.g., eight) insertion holes 23C are formed in the peripheral wall portion 23B of the second frame 23. The multiple insertion holes 21C are arranged at equal intervals along the circumferential direction. Similarly, the multiple insertion holes 23C are arranged at equal intervals along the circumferential direction. Bolts 50 are inserted into each insertion hole 21C and insertion hole 23C from the other side in the axial direction.

[0030] Multiple protrusions 21D are formed on the circumferential wall portion 21B of the first frame 21 on the other axial end. The multiple protrusions 21D project toward the other axial direction. The multiple protrusions 21D are arranged at equal intervals along the circumferential direction. Each protrusion 21D is positioned in the center of a pair of circumferentially adjacent insertion holes 21C.

[0031] Multiple protrusions 23D are formed on one axial end of the peripheral wall portion 23B of the second frame 23. The multiple protrusions 23D project toward one axial direction. The multiple protrusions 23D are arranged at equal intervals along the circumferential direction. Each protrusion 23D is positioned in the center of a pair of circumferentially adjacent insertion holes 23C.

[0032] The multiple protrusions 23D are positioned at a 90° offset in the circumferential direction from the multiple protrusions 21D. The protrusions 21D of the first frame 21 and the protrusions 23D of the second frame 23 are fitted into the notches 26F of the core 26, thereby preventing the core 26 from rotating relative to the first frame 21 and the second frame 23.

[0033] A bolt 50 is inserted into the insertion hole 21C and the insertion hole 23C from the other axial side, and a nut 56 is screwed onto the bolt 50 from the one axial side. As a result, the core 26 is fixed to the first frame 21 and the second frame 23 with the outer flange portion 26C of the core 26 sandwiched between the peripheral wall portion 21B of the first frame 21 and the peripheral wall portion 23B of the second frame 23. In other words, the stator 14 is fixed to the first frame 21 and the second frame 23.

[0034] As shown in Figure 3, the first opposing surface 26D of the teeth portion 26A has a teeth portion-side inclined surface 26D1 that inclins radially outward towards the other axial side. Similarly, the second opposing surface 26E of the teeth portion 26A has a teeth portion-side inclined surface 26E1 that inclins radially outward towards one axial side. The radially inner end of the first opposing surface 26D is formed as a teeth portion-side vertical surface 26D2 that is perpendicular to the axial direction. Similarly, the radially inner end of the second opposing surface 26E is formed as a teeth portion-side vertical surface 26E2 that is perpendicular to the axial direction.

[0035] Furthermore, the other axial side surface of the first magnet 18 has a magnet-side inclined surface 18A1 that is inclined in the same direction as the teeth-side inclined surface 26D1. Similarly, the one axial side surface of the second magnet 19 has a magnet-side inclined surface 19A1 that is inclined in the same direction as the teeth-side inclined surface 26E1. The radially inner end of the other axial side surface of the first magnet 18 is formed as a magnet-side vertical surface 18A2 that is perpendicular to the axial direction. Similarly, the radially inner end of the one axial side surface of the second magnet 19 is formed as a magnet-side vertical surface 19A2 that is perpendicular to the axial direction.

[0036] The inclined surface 26D1 on the teeth side and the inclined surface 18A1 on the magnet side are opposite each other in the axial direction, and the inclined surface 26E1 on the teeth side and the inclined surface 19A1 on the magnet side are opposite each other in the axial direction. Also, the vertical surface 26D2 on the teeth side and the vertical surface 18A2 on the magnet side are opposite each other in the axial direction, and the vertical surface 26E2 on the teeth side and the vertical surface 19A2 on the magnet side are opposite each other in the axial direction.

[0037] Next, the assembly and disassembly methods for the motor 10 will be described.

[0038] The assembly method for the motor 10 includes a stacking step in which the components constituting the motor 10 are stacked from one side in the axial direction. In the stacking step, the second support member 25, the second magnet 19, the second coil 32, the core 26, the first coil 31, the first magnet 18, the first support member 24, and the first frame 21 are stacked on the second frame 23 from one side in the axial direction. In this way, the assembly method for the motor 10 allows the motor 10 to be assembled by a one-way assembly in which the components constituting the motor 10 are stacked from one side in the axial direction.

[0039] The rotating shaft 22 is assembled at an appropriate timing. The second support member 25 and the second magnet 19 may be assembled as a single unit. Similarly, the first support member 24 and the first magnet 18 may be assembled as a single unit. The first coil 31, the core 26, and the second coil 32 may be assembled as a single unit. Some of the components constituting the motor 10 may also be assembled as a single unit.

[0040] Furthermore, in each coil layer 54 constituting the first coil 31, the inner ends and outer ends of the multiple segment conductors 60 stacked in two stages in the axial direction are joined together from the axial direction. The joining process of the multiple segment conductors 60 may be performed immediately after the multiple segment conductors 60 are stacked as components constituting the motor 10, or it may be performed before the multiple segment conductors 60 are stacked as components constituting the motor 10.

[0041] On the other hand, in the disassembly method for the motor 10, in the reverse of the assembly method described above, the first frame 21, first support member 24, first magnet 18, first coil 31, core 26, second coil 32, second magnet 19, and second support member 25 are removed in order from the second frame 23 toward one axial direction. In this way, the motor 10 can be disassembled by unidirectional separation, in which the components constituting the motor 10 are removed toward one axial direction.

[0042] It should be noted that the rotating shaft 22 is removed at an appropriate timing. Further, the first support member 24 and the first magnet 18 may be removed in an integrated state. Similarly, the second support member 25 and the second magnet 19 may be removed in an integrated state. Further, the first coil 31, the core 26, and the second coil 32 may be removed in an integrated state. Furthermore, some of the members constituting the motor 10 may be removed in an integrated state.

[0043] Next, first to third embodiments of the technology of the present disclosure will be described. The first to third embodiments are embodiments applicable to the motor 10 described above. Note that, since the configuration on the other axial side of the motor 10 (that is, the configuration on the second axial gap side) is axially symmetrical to the configuration on one axial side of the motor 10 (that is, the configuration on the first axial gap side), the configuration on one axial side of the motor 10 will be described below, and description of the configuration on the other axial side of the motor 10 will be omitted.

[0044] [First Embodiment] First, the first embodiment of the technology of the present disclosure will be described.

[0045] As shown in FIG. 4 and FIG. 5, in the first embodiment, an inner annular support member 70A and an outer annular support member 70B are provided in the gap 13 between the stator 14 and the rotor 12. The inner annular support member 70A and the outer annular support member 70B support the rotor 12 with respect to the stator 14 by being provided in the gap 13. The inner annular support member 70A and the outer annular support member 70B are an example of the "support portion" according to the technology of the present disclosure.

[0046] The inner annular support member 70A and the outer annular support member 70B function as sliding members (in other words, bearing members) that slide relative to the stator 14 or the rotor 12 as the rotor 12 rotates. The dimension of the gap 13 may be adjusted by adjusting the diameters of the inner annular support member 70A and the outer annular support member 70B.

[0047] More specifically, the gap 13 provided with the inner annular support member 70A and the outer annular support member 70B is a gap between the core 26 and the first magnet 18. More specifically, the inner annular support member 70A and the outer annular support member 70B support the first magnet 18 with respect to the core 26. The inner annular support member 70A may be fixed to either one of the stator 14 and the rotor 12, and the outer annular support member 70B may also be fixed to either one of the stator 14 and the rotor 12.

[0048] The inner annular support member 70A and the outer annular support member 70B are each formed in an annular shape around the axial direction. The inner annular support member 70A is located at a radially inner portion (that is, an inner peripheral portion) of the stator 14 and the rotor 12, and the outer annular support member 70B is located at a radially outer portion (that is, an outer peripheral portion) of the stator 14 and the rotor 12. More specifically, the inner annular support member 70A is disposed at a radially inner portion of the core 26 and the first magnet 18, and the outer annular support member 70B is disposed at a radially outer portion of the core 26 and the first magnet 18. The outer annular support member 70B is an example of the "outer support section" according to the technology of the present disclosure.

[0049] The inner annular support member 70A is formed, for example, to have a circular cross-section. Similarly, the outer annular support member 70B is formed, for example, to have a circular cross-section. Note that the inner annular support member 70A and the outer annular support member 70B may each be formed to have a cross-sectional shape other than a circular cross-section. Further, at least one of the stator 14 and the rotor 12 may be provided with a groove for holding the inner annular support member 70A that is annularly formed around the axial direction. Similarly, at least one of the stator 14 and the rotor 12 may be provided with a groove for holding the outer annular support member 70B that is annularly formed around the axial direction.

[0050] As shown in Figure 6, the core 26 has a plurality of teeth portions 26A arranged in the direction around the axial direction (i.e., the circumferential direction indicated by arrow C). The inner annular support member 70A has a plurality of magnetic portions 72A arranged in the direction around the axial direction and a non-magnetic portion 74A provided between the plurality of magnetic portions 72A. The magnetic portions 72A may be formed of, for example, sintered oil-impregnated material or iron. The non-magnetic portion 74A may be formed of, for example, resin, stainless steel, or aluminum alloy.

[0051] Each of the multiple magnetic sections 72A corresponds to each of the multiple tooth sections 26A. Specifically, the number of magnetic sections 72A is the same as the number of tooth sections 26A, and each magnetic section 72A has the same width as each tooth section 26A.

[0052] Similarly, as shown in Figure 7, the outer annular support member 70B has a plurality of magnetic portions 72B arranged in the axial direction and non-magnetic portions 74B provided between the plurality of magnetic portions 72B. Each of the plurality of magnetic portions 72B corresponds to each of the plurality of teeth portions 26A. Specifically, the number of plurality of magnetic portions 72B is the same as the number of plurality of teeth portions 26A, and each magnetic portion 72B has the same width as each of the teeth portions 26A.

[0053] As described above, in the first embodiment, an inner annular support member 70A and an outer annular support member 70B are provided in the gap 13 between the stator 14 and the rotor 12. Here, the inner annular support member 70A and the outer annular support member 70B are each formed in an annular shape around the axial direction. Therefore, when assembling or disassembling the motor 10, the inner annular support member 70A and the outer annular support member 70B can be kept in an integrated state. This makes it possible to maintain the gap 13 between the stator 14 and the rotor 12 while facilitating the work during assembly or disassembly.

[0054] Furthermore, as shown in Figure 8, an attractive force F from the stator 14 acts on the rotor 12. Here, the radially outer portions of the stator 14 and rotor 12 have a longer moment length from the rotation axis 22 compared to the radially inner portions of the stator 14 and rotor 12, so the load due to the attractive force F is larger due to the longer moment length. However, an outer annular support member 70B is positioned on the radially outer portions of the stator 14 and rotor 12. Therefore, the outer annular support member 70B supports the load due to the longer moment length from the rotation axis 22, so the deflection of the rotor 12 (especially the deflection of the first support member 24) due to the attractive force F can be suppressed.

[0055] Furthermore, as shown in Figure 6, the inner annular support member 70A has a plurality of magnetic parts 72A arranged in the axial direction, and each of the plurality of magnetic parts 72A corresponds to each of the plurality of tooth parts 26A. Therefore, by arranging the magnetic parts 72A between the first magnet 18 and the tooth parts 26A, magnetic flux M can flow between the first magnet 18 and the tooth parts 26A via the magnetic parts 72A. This reduces the magnetic resistance between the first magnet 18 and the tooth parts 26A. In addition, non-magnetic parts 74A are provided between the plurality of magnetic parts 72A. Therefore, when magnetic flux M flows between the first magnet 18 and the tooth parts 26A via the magnetic parts 72A, leakage of magnetic flux M can be suppressed.

[0056] Similarly, as shown in Figure 7, the outer annular support member 70B has a plurality of magnetic parts 72B arranged in the axial direction, and each of the plurality of magnetic parts 72B corresponds to each of the plurality of teeth parts 26A. Therefore, by arranging the magnetic parts 72B between the first magnet 18 and the teeth parts 26A, magnetic flux M can flow between the first magnet 18 and the teeth parts 26A via the magnetic parts 72B. This reduces the magnetic resistance between the first magnet 18 and the teeth parts 26A. In addition, non-magnetic parts 74B are provided between the plurality of magnetic parts 72B. Therefore, when magnetic flux M flows between the first magnet 18 and the teeth parts 26A via the magnetic parts 72B, leakage of magnetic flux M can be suppressed. With the configuration shown in Figures 6 and 7 described above, it is possible to achieve high torque or miniaturization of the motor 10.

[0057] Furthermore, as shown in Figure 5, the inner annular support member 70A and the outer annular support member 70B are provided between the teeth-side inclined surface 26D1 and the magnet-side inclined surface 18A1. Therefore, the rotor 12 can be positioned in the axial and radial directions relative to the stator 14.

[0058] As shown in Figure 9, an annular support member 70 may be provided in the gap 13 between the stator 14 and the rotor 12 instead of the inner annular support member 70A and the outer annular support member 70B. The annular support member 70 may be provided at any position in the radial direction of the stator 14 and the rotor 12. The annular support member 70 is an example of a "support part" according to the technology of this disclosure.

[0059] Furthermore, the annular support member 70 may be provided on the outermost diameter portion of the first support member 24 and the core 26 (more specifically, the gap between the peripheral wall portion 21B and the outer flange portion 26C shown in Figure 3), as an example of the radially outer portion of the stator 14 and rotor 12. Even with this configuration, the annular support member 70 supports the load corresponding to the long moment length from the rotation axis 22, so the deflection of the rotor 12 (especially the deflection of the first support member 24) due to the suction force F can be suppressed.

[0060] Furthermore, in addition to the inner annular support member 70A and the outer annular support member 70B, an intermediate annular support member (not shown) located between the inner annular support member 70A and the outer annular support member 70B may be provided in the gap 13 between the stator 14 and the rotor 12. Also, there may be any number of annular support members arranged concentrically in the gap 13 between the stator 14 and the rotor 12.

[0061] [Second Embodiment] Next, a second embodiment of the technology of the present disclosure will be described.

[0062] As shown in Figure 10, in the second embodiment, a ball retainer 80 is provided in the gap 13 between the stator 14 and the rotor 12. The ball retainer 80 has a plurality of balls 82 and a retainer ring 84 (see also Figure 11). The plurality of balls 82 support the rotor 12 relative to the stator 14 by being provided in the gap 13. The balls 82 are an example of a "support part" according to the technology of this disclosure.

[0063] The ball 82 functions as a sliding member (in other words, a bearing member) that slides against the stator 14 or the rotor 12 as the rotor 12 rotates. The dimensions of the gap 13 may be adjusted by adjusting the diameter of the ball 82.

[0064] Multiple balls 82 are arranged at equal intervals around the axial direction. The number of multiple balls 82 can be any number, but three or more are preferred. The balls 82 are formed in a spherical shape and, more specifically, support the first magnet 18 with respect to the core 26.

[0065] The retainer ring 84 is formed in an annular shape around the axial direction. The retainer ring 84 has a plurality of retaining portions 86, each of which holds a plurality of balls 82. The retainer ring 84 is an example of an "annular retaining member" according to the technology of this disclosure. Each retaining portion 86 is formed in an annular shape that surrounds a ball 82, for example.

[0066] The core 26 (specifically, the first teeth portion 26A) has a first opposing surface 26D that faces the first magnet 18 via a gap 13 in the axial direction, and the first magnet 18 has a second opposing surface 18A that faces the core 26 (specifically, the first teeth portion 26A) via a gap 13 in the axial direction. The first opposing surface 26D and the second opposing surface 18A are examples of the "first opposing surface" and "second opposing surface" according to the technology of this disclosure.

[0067] The first opposing surface 26D and the second opposing surface 18A have a teeth-side inclined surface 26D1 and a magnet-side inclined surface 18A1 that are inclined with respect to a plane perpendicular to the axial direction. Specifically, the first opposing surface 26D has a teeth-side inclined surface 26D1 that is inclined toward the other axial direction as it extends radially outward, and the second opposing surface 18A has a magnet-side inclined surface 18A1 that is inclined toward the other axial direction as it extends radially outward. The teeth-side inclined surface 26D1 and the magnet-side inclined surface 18A1 are examples of the "first inclined surface" and "second inclined surface" according to the technology of this disclosure.

[0068] The retainer ring 84 is formed in the shape of a frustoconical cone, having an inclination that corresponds to the inclination of the tooth-side inclined surface 26D1 and the magnet-side inclined surface 18A1. Specifically, in a longitudinal cross-sectional view of the motor 10, the retainer ring 84 is formed inclined along the tooth-side inclined surface 26D1 and the magnet-side inclined surface 18A1.

[0069] Multiple recesses 88 are formed on the inclined surface 26D1 on the teeth side (see also Figure 12). The multiple recesses 88 are formed at equal intervals around the axial direction. Each recess 88 is formed in a circular shape when viewed in the axial direction. The portion of the ball 82 that is on the core 26 side is accommodated in each recess 88. In addition, a groove 90 is formed on the inclined surface 18A1 on the magnet side (see also Figure 13). The groove 90 is formed in an annular shape around the axial direction. The portion of the ball 82 that is on the magnet side is accommodated in the groove 90. Note that multiple recesses 88 may be formed on the first magnet 18 and a groove 90 may be formed on the core 26.

[0070] As described above, in the second embodiment, a ball retainer 80 is provided in the gap 13 between the stator 14 and the rotor 12. Here, the ball retainer 80 is configured such that a plurality of balls 82 are held by a retainer ring 84. Therefore, when assembling or disassembling the motor 10, the plurality of balls 82 can be kept held by the retainer ring 84. This makes it possible to maintain the gap 13 between the stator 14 and the rotor 12 while facilitating the assembly or disassembly process.

[0071] Furthermore, as shown in Figure 10, the retainer ring 84 is formed in a frustoconical shape with an inclination corresponding to the inclination of the tooth-side inclined surface 26D1 and the magnet-side inclined surface 18A1. Therefore, even if the core 26 and the first magnet 18 have a tooth-side inclined surface 26D1 and a magnet-side inclined surface 18A1, and a gap 13 is formed between the tooth-side inclined surface 26D1 and the magnet-side inclined surface 18A1, the retainer ring 84 can be positioned along the inclination of the tooth-side inclined surface 26D1 and the magnet-side inclined surface 18A1. This makes it possible to suppress the widening of the gap 13 compared to, for example, when the retainer ring 84 is formed in a cylindrical shape parallel to the axial direction or in a flat plate shape perpendicular to the axial direction.

[0072] Furthermore, the retainer ring 84 is provided between the inclined surface 26D1 on the teeth side and the inclined surface 18A1 on the magnet side. Therefore, the rotor 12 can be positioned in the axial and radial directions relative to the stator 14.

[0073] As shown in Figure 14, the ball retainer 80 may be positioned on the radially outer portion of the stator 14 and rotor 12. With this configuration, as described in the first embodiment (see Figure 8), the ball retainer 80 supports the load corresponding to the longer moment length from the rotation axis 22, thereby suppressing the deflection of the rotor 12 (especially the deflection of the first support member 24) due to the suction force F.

[0074] Furthermore, as shown in Figure 15, the ball retainer 80 may be provided in the outermost diameter portion of the first support member 24 and the core 26 (more specifically, the gap between the peripheral wall portion 21B and the outer flange portion 26C), as an example of the radially outer portion of the stator 14 and rotor 12. Even with this configuration, as described in the first embodiment (see Figure 8), the ball retainer 80 supports the load corresponding to the longer moment length from the rotation axis 22, thereby suppressing the deflection of the rotor 12 (especially the deflection of the first support member 24) due to the suction force F.

[0075] In the examples shown in Figures 14 and 15, the multiple balls 82 are examples of the "outer support portion" according to the technology of this disclosure.

[0076] Furthermore, multiple ball retainers 80 with different outer diameters may be provided concentrically in the gap 13 between the stator 14 and the rotor 12. In this case, the number of ball retainers 80 may be any number.

[0077] [Third Embodiment] Next, a third embodiment of the technology of the present disclosure will be described.

[0078] As shown in Figure 16, in the third embodiment, an inner projection 100A and an outer projection 100B are provided in the gap 13 between the stator 14 and the rotor 12. For example, the inner projection 100A and the outer projection 100B are integrally formed with the first magnet 18 and protrude toward the core 26. The inner projection 100A and the outer projection 100B support the rotor 12 relative to the stator 14 by being provided in the gap 13. Specifically, the inner projection 100A and the outer projection 100B support the rotor 12 relative to the stator 14 by abutting against the first teeth portion 26A. The inner projection 100A and the outer projection 100B are examples of "support portions" according to the technology of this disclosure.

[0079] The inner projection 100A and the outer projection 100B function as sliding parts (in other words, bearing parts) that slide against the core 26 as the rotor 12 rotates. The dimensions of the gap 13 may be adjusted by adjusting the protrusion height of the inner projection 100A and the outer projection 100B.

[0080] The inner projection 100A and the outer projection 100B are more specifically formed on the magnet-side inclined surface 18A1. The inner projection 100A and the outer projection 100B are each formed in an annular shape around the axial direction (see Figure 17). The inner projection 100A is located on the radially inner portion (i.e., the inner circumference) of the stator 14 and rotor 12, and the outer projection 100B is located on the radially outer portion (i.e., the outer circumference) of the stator 14 and rotor 12. More specifically, the inner projection 100A is formed on the radially inner portion of the magnet-side inclined surface 18A1, and the outer annular support member 70B is formed on the radially outer portion of the magnet-side inclined surface 18A1. The outer projection 100B is an example of an "outer support portion" according to the technology of this disclosure.

[0081] The inner projection 100A is formed, for example, with a semicircular cross-section. Similarly, the outer projection 100B is formed, for example, with a semicircular cross-section. Note that the inner projection 100A and the outer projection 100B may each be formed with a cross-sectional shape other than a semicircular shape.

[0082] As described above, in the third embodiment, the gap 13 between the stator 14 and the rotor 12 is provided with an inner projection 100A and an outer projection 100B. Here, the inner projection 100A and the outer projection 100B are integrally formed with the first magnet 18. Therefore, when assembling or disassembling the motor 10, the inner projection 100A and the outer projection 100B can be kept integral with the first magnet 18. This makes it possible to maintain the gap 13 between the stator 14 and the rotor 12 while facilitating the assembly or disassembly process.

[0083] Furthermore, the outer projection 100B is located on the radially outer portion of the stator 14 and rotor 12. Therefore, as in the description of the first embodiment (see Figure 8), the outer projection 100B supports the load corresponding to the longer moment length from the rotation axis 22, thereby suppressing the deflection of the rotor 12 (especially the deflection of the first support member 24) due to the suction force F.

[0084] Furthermore, since the inner projection 100A and the outer projection 100B are integrally formed with the first magnet 18, the number of parts and assembly man-hours can be reduced.

[0085] Furthermore, the inner projection 100A and the outer projection 100B are provided between the teeth-side inclined surface 26D1 and the magnet-side inclined surface 18A1. Therefore, the rotor 12 can be positioned in the axial and radial directions relative to the stator 14.

[0086] As shown in Figure 18, the first magnet 18 may have a plurality of inner protrusions 100A and a plurality of outer protrusions 100B. The plurality of inner protrusions 100A may be formed at equal intervals around the axial direction. Similarly, the plurality of outer protrusions 100B may be formed at equal intervals around the axial direction. Each inner protrusion 100A and each outer protrusion 100B may be formed in a circular shape when viewed in the axial direction. The number of plurality of inner protrusions 100A may be any number, but it is preferable to have three or more. Similarly, the number of plurality of outer protrusions 100B may be any number, but it is preferable to have three or more.

[0087] Furthermore, as shown in Figure 19, the first magnet 18 may have a projection 100 formed in an annular shape around the axial direction instead of the plurality of inner projections 100A and the plurality of outer projections 100B. The projection 100 may be provided at any position in the radial direction of the stator 14 and rotor 12. Also, the first magnet 18 may have a plurality of projections 100. The plurality of projections 100 may be formed at equal intervals around the axial direction.

[0088] Furthermore, as shown in Figure 20, the inner projection 100A and the outer projection 100B may be integrally formed with the core 26. Specifically, the inner projection 100A and the outer projection 100B may be formed on the inclined surface 26D1 on the teeth side. The core 26 may also be formed from, for example, a compacted magnetic core, an electromagnetic steel sheet, or a silicon steel sheet.

[0089] Furthermore, as shown in Figures 21 and 22, the projection 100 may also be provided on the outermost diameter portion of the first support member 24 and core 26 (more specifically, the gap between the peripheral wall portion 21B and the outer flange portion 26C), as an example of the radially outer portion of the stator 14 and rotor 12. The projection 100 may also be integrally formed with the core 26 (see Figure 21) or integrally formed with the first support member 24 (see Figure 22). Even with this configuration, the ball retainer 80 supports the load corresponding to the long moment length from the rotation axis 22, so the deflection of the rotor 12 (especially the deflection of the first support member 24) due to the suction force F can be suppressed.

[0090] In the examples shown in Figures 21 and 22, the projection 100 is an example of an "outer support portion" according to the technology of this disclosure. Also, the first support member 24 is an example of a "magnet support member" according to the technology of this disclosure.

[0091] Furthermore, in the example shown in Figure 21, the first support member 24 may be formed of resin. Also, the sliding surface of the first support member 24 with respect to the projection 100 may be formed of a metal member. The metal member may be integrated with the first support member 24 by insert molding or two-color molding, etc.

[0092] Furthermore, in the example shown in Figure 22, the first support member 24 may be made of resin, and the projection 100 may be made of a metal member. The projection 100 may be integrated with the first support member 24 by insert molding or two-color molding.

[0093] Furthermore, the projection 100 may be integrally formed on at least two or more members of the core 26, the first magnet 18, and the first support member 24.

[0094] [Fourth Embodiment] Next, a fourth embodiment of the technology of the present disclosure will be described.

[0095] In the fourth embodiment, the motor life prediction will be described. Here, the annular support member 70 shown in Figure 9 will be used as an example. When the annular support member 70 wears beyond a specified value, the motor 10 reaches the end of its life. The specified value can be set arbitrarily.

[0096] Figure 23 schematically shows the progression of wear of the annular support member 70. Line L1 shows the initial state when the motor 10 is not in use, line L2 shows the state when the motor 10 has been used for a certain period of time, and line L3 shows the state when the motor 10 has reached the end of its lifespan. Figure 24 also shows an example of the relationship between the current supplied to the motor 10 and the torque. Graph line G1 shows the initial state when the motor 10 is not in use, graph line G2 shows the state when the motor 10 has been used for a certain period of time, and graph line G3 shows the state when the motor 10 has reached the end of its lifespan.

[0097] The torque at which motor 10 reaches the end of its lifespan can be obtained in advance from a motor 10 that has reached the end of its lifespan. As the annular support member 70 wears down, the magnetic resistance decreases, causing the torque to increase. By measuring the torque of the motor 10 that is the subject of lifespan prediction after using it for a certain period of time, and calculating the difference between the measured torque and the torque obtained in advance from another motor 10 that has reached the end of its lifespan, the remaining lifespan can be calculated based on the calculated difference. This makes it possible to predict the lifespan of motor 10.

[0098] Next, we will describe some common modifications to the above embodiments.

[0099] Furthermore, in each of the above embodiments, the multiple segment conductors 60 may each be formed by a copper pattern on a printed circuit board.

[0100] Furthermore, although the motor 10 is configured as a double axial gap motor in each of the above embodiments, it may also be configured as a single axial gap motor, in which either the configuration on one axial side or the configuration on the other axial side is omitted.

[0101] Furthermore, the motor 10 may also be configured in which multiple sets of rotor 12 and stator 14 are arranged in the axial direction.

[0102] Furthermore, any of the above-mentioned technologies that can be combined may be combined as appropriate.

[0103] Although one embodiment of the technology of this disclosure has been described above, the present invention is not limited to the above, and it is of course possible to implement it in various modified forms without departing from the spirit of the invention.

[0104] The following are additional notes regarding the technology of the present disclosure. (Note 1) An axial gap motor (10) comprising: a stator (14); a rotor (12) facing the stator via a gap (13) in the axial direction of the stator, wherein the gap is provided with support portions (70, 70A, 70B, 82, 100, 100A, 100B) that support the rotor relative to the stator, and the support portions are either annular support members (70, 70A, 70B) formed annularly around the axial direction, or held by an annular holding member (84) formed annularly around the axial direction, or integrally formed with at least one of the stator and the rotor. (Note 2) The axial gap motor according to Note 1, wherein the support portions are arranged on the radially outer portions of the stator and the rotor. (Note 3) The axial gap motor according to Note 1 or Note 2, wherein the stator has a core (26), the core has a plurality of teeth (26A) arranged in the direction around the axial direction, and the support has a plurality of magnetic parts (72A, 72B) arranged in the direction around the axial direction and corresponding to each of the plurality of teeth, and non-magnetic parts (74A, 74B) provided between the plurality of magnetic parts. (Note 4) The axial gap motor according to any one of Notes 1 to 3, wherein the stator has a core, the rotor has a magnet (18) facing the core via the gap in the axial direction, the core has a first opposing surface (26D) facing the magnet, the magnet has a second opposing surface (18A) facing the core, the first opposing surface and the second opposing surface each have a first inclined surface (26D1) and a second inclined surface (18A1) that are inclined with respect to a plane perpendicular to the axial direction, the support portion is held by the annular holding member, and the annular holding member is formed in the shape of a frustoconical cone having an inclination corresponding to the inclination of the first inclined surface and the second inclined surface.(Note 5) The axial gap motor according to any one of Notes 1 to 4, wherein the stator has a core, the rotor has a magnet facing the core through the gap in the axial direction, and a magnet support member (24) supporting the magnet, and the support portion is integrally formed with at least one of the core, the magnet, and the magnet support member.

Claims

Stator (14) and, A rotor (12) facing the stator via a gap (13) in the axial direction of the stator, Equipped with, The gap is provided with support portions (70, 70A, 70B, 82, 100, 100A, 100B) that support the rotor relative to the stator. The support portion is an annular support member (70, 70A, 70B) formed annularly around the axial direction, or is held by an annular holding member (84) formed annularly around the axial direction, or is integrally formed with at least one of the stator and the rotor. Axial gap motor (10). 　 The support portion is located on the radially outer portion of the stator and the rotor. The axial gap motor according to claim 1. 　 The stator has a core (26), The core has a plurality of teeth (26A) arranged in the direction around the axial direction, The aforementioned support portion is Arranged in the direction around the axial direction, a plurality of magnetic parts (72A, 72B) corresponding to each of the plurality of teeth parts, It has non-magnetic parts (74A, 74B) provided between a plurality of magnetic parts, The axial gap motor according to claim 1 or claim 2. 　 The stator has a core, The rotor has a magnet (18) facing the core through the gap in the axial direction, The core has a first opposing surface (26D) that faces the magnet, The magnet has a second opposing surface (18A) that faces the core, The first opposing surface and the second opposing surface each have a first inclined surface (26D1) and a second inclined surface (18A1) that are inclined with respect to a surface perpendicular to the axial direction, The support portion is held by the annular holding member, The annular holding member is formed in the shape of a frustoconical cone having an inclination corresponding to the inclination of the first inclined surface and the second inclined surface. An axial gap motor according to any one of claims 1 to 3. 　 The stator has a core, The rotor is A magnet facing the core via the gap in the axial direction, The magnet has a magnet support member (24) that supports the magnet, The support portion is integrally formed with at least one of the core, the magnet, and the magnet support member. An axial gap motor according to any one of claims 1 to 4.

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