Axial gap motor, and method for manufacturing axial gap motor

Abstract

The present invention provides an axial gap motor comprising: a rotor; a stator positioned across a gap of a designed length in the direction of a rotation shaft of the rotor; a shaft that is the rotating shaft of the rotor; a first bearing that rotatably supports the shaft; a case having a first plane in which the stator is placed; and an adjustment member that supports the first bearing. The adjustment member has a male thread that is threaded into the case, and the first bearing moves in the axial direction of the shaft due to rotation of the adjustment member.

Description

Axial gap motor and manufacturing method thereof

[0001] The present disclosure relates to an axial gap motor and a method for manufacturing an axial gap motor. This application claims priority to Japanese Patent Application No. 2021-086466 filed on May 21, 2021, and incorporates by reference all of the contents of that application.

[0002] As shown in FIG. 10 of Patent Document 1, the axial gap type rotating electric machine of Patent Document 1 includes a case, a stator, a rotor, a shaft, and bearings. The case includes a cylindrical peripheral wall portion and a pair of disk-shaped plates. The pair of plates are attached to both ends of the peripheral wall portion. A through hole is formed in the center of the pair of plates. A shaft is provided in the through hole. The stator and rotor are arranged facing each other in the axial direction of the shaft inside the case. The stator is arranged on the plates. The rotor is provided with a gap between them. The shaft is the rotating axis of the rotor. The bearings support the shaft so that it can rotate freely.

[0003] Japanese Patent Application Laid-Open No. 2020-108323

[0004] The axial gap motor of the present disclosure comprises: a rotor; a stator arranged with a gap of a design length in the direction of the rotor's rotational axis; a shaft which is the rotor's rotational axis; a first bearing which rotatably supports the shaft; a case having a first flat surface on which the stator is placed; and an adjustment member which supports the first bearing; the adjustment member has a screw thread which is screwed to the case; and the first bearing moves in the axial direction of the shaft by rotation of the adjustment member.

[0005] The manufacturing method of the axial gap motor disclosed herein comprises a step of preparing parts for an axial gap motor, and a step of assembling the parts, wherein the parts include a rotor, a stator, a shaft which is the rotation axis of the rotor, a bearing which rotatably supports the shaft, a case having a first plane on which the stator is mounted, and an adjustment member which is screwed to the case to support the bearing, wherein the stator has a stator core having a yoke and a plurality of teeth, and a coil arranged on each of the plurality of teeth, and in the step of assembling the parts, the length of the gap between the rotor and the stator is set to a designed length by rotating the adjustment member relative to the case to raise and lower the shaft via the bearing, and the amount of rotation of the adjustment member is determined based on the value of the induced voltage generated in the coil.

[0006] FIG. 1 is a cross-sectional schematic diagram showing an overview of an axial gap motor according to embodiment 1. FIG. 2 is a cross-sectional schematic diagram showing an enlarged view of region A in FIG. 1. FIG. 3 is a cross-sectional schematic diagram showing an enlarged view of another example of region A in FIG. 1. FIG. 4 is a cross-sectional schematic diagram showing an enlarged view of region B in FIG. 1. FIG. 5 is a cross-sectional schematic diagram showing an enlarged view of region C in FIGS. 2 and 3. FIG. 6 is a cross-sectional schematic diagram for explaining a method for manufacturing an axial gap motor according to embodiment 1. FIG. 7 is a graph showing changes in induced voltage values. FIG. 8 is a graph showing changes in induced voltage values. FIG. 9 is a cross-sectional schematic diagram for explaining a method for manufacturing an axial gap motor according to a modified example. FIG. 10 is a plan view schematic showing an overview of a circuit board. FIG. 11 is a cross-sectional schematic diagram showing an enlarged view of a portion of an axial gap motor according to embodiment 2.

[0007] [Problem to be Solved by the Present Disclosure] It is desired to improve the manufacturability of axial gap motors that have excellent assembly precision.

[0008] An object of the present disclosure is to provide an axial gap motor that is excellent in assembly precision. Another object of the present disclosure is to provide a method for manufacturing an axial gap motor that is excellent in manufacturability.

[0009] [Advantages of the Present Disclosure] The axial gap motor of the present disclosure has excellent assembly precision.

[0010] The manufacturing method of the axial gap motor of the present disclosure is excellent in manufacturability of the axial gap motor of the present disclosure.

[0011] Description of an embodiment of the present disclosure An axial gap motor is manufactured, for example, through two assembly processes: a temporary assembly of the parts of the axial gap motor and a final assembly. The reason for temporary assembly of the parts is that it is difficult to assemble the parts once to achieve the designed gap length between the stator and rotor. The designed gap length is a target value for the designed gap length determined based on the specifications of the axial gap motor. Therefore, the gap length of the axial gap motor manufactured through temporary assembly is measured. The difference between the measured gap length and the designed gap length is calculated. After the measured gap length is calculated, the axial gap motor is disassembled.

[0012] The parts are assembled using a shim with a thickness equal to the difference. The shim is placed between the bearing and the plate. By placing the shim, the bearing is moved away from the plate by the thickness of the shim. By moving the bearing away, the shaft supported by the bearing is shifted in the axial direction of the shaft. By shifting the shaft, the rotor is moved away from the stator. By moving the rotor away, the length of the gap becomes longer than the measured length. In other words, the length of the gap becomes longer than the measured length by the thickness of the shim. By making the thickness of the shim the same as the difference, the length of the gap can be made the designed length.

[0013] The manufacturing method described above requires assembling parts twice, which makes the manufacturing process complicated. Furthermore, the number of parts increases by the number of shims used. Furthermore, the use of shims increases the preload on the bearings, which can lead to increased mechanical loss.

[0014] The present inventors have conducted extensive research into a method for manufacturing an axial gap motor without using a shim. As a result, the present inventors have developed a manufacturing method that allows the length of the gap between the stator and rotor to be substantially the same as the designed length by assembling parts only once. First, embodiments of the present disclosure will be listed and described.

[0015] (1) An axial gap motor according to one aspect of the present disclosure comprises: a rotor; a stator arranged with a gap of a design length in the direction of the rotor's rotational axis; a shaft that is the rotor's rotational axis; a first bearing that rotatably supports the shaft; a case having a first flat surface on which the stator is placed; and an adjustment member that supports the first bearing, wherein the adjustment member has a screw thread that is screwed to the case; and the first bearing moves in the axial direction of the shaft by rotation of the adjustment member.

[0016] The axial gap motor has excellent assembly precision. By rotating the adjustment member relative to the case during the manufacturing process, the first bearing can be moved in the axial direction of the shaft. Because the shaft is supported by the first bearing, the shaft can be moved in the axial direction by moving the first bearing in the axial direction. Because the shaft is the rotation axis of the rotor, the rotor can be moved in the axial direction by moving the shaft in the axial direction. In other words, the rotor can be easily moved to a position where the gap length is the designed length. Because the adjustment member and the case are threadedly connected, the rotor will not move in the axial direction unless the adjustment member is rotated. Therefore, the rotor is positioned at a position where the gap length is the designed length.

[0017] The axial gap motor does not include a shim, which can prevent an increase in the number of parts. Furthermore, the axial gap motor can prevent an increase in preload of the first bearing, which can prevent an increase in mechanical loss.

[0018] (2) In the axial gap motor of (1) above, the pitch of the thread of the adjustment member may be 2.5 mm or less.

[0019] The axial gap motor described above has excellent assembly precision because the gap length can be easily and precisely adjusted using an adjustment member.

[0020] (3) The axial gap motor of (1) or (2) above may further include a second bearing that rotatably supports the shaft and is arranged opposite the first bearing across the rotor, and an elastic member that presses the second bearing toward the first bearing.

[0021] The axial gap motor described above makes it easy to suppress rattle at the screw-connected portion between the case and the adjustment member.

[0022] (4) In the axial gap motor of any one of (1) to (3), the first bearing may be a radial bearing having an inner race and an outer race, and the adjustment member may support the outer race without contacting the inner race.

[0023] The axial gear type motor can suppress an increase in mechanical loss because the adjustment member does not contact the inner race, so there is no increase in friction.

[0024] (5) The axial gap motor of (4) above may further include a washer disposed between the outer race and the adjustment member.

[0025] In the above-mentioned axial gap motor, the washer is disposed between the outer race and the adjustment member, which makes it easy for the adjustment member to support the bearing. Furthermore, in the above-mentioned axial gap motor, the adjustment member can be configured as a solid body. This is because the washer can prevent contact between the adjustment member and the inner race even if the adjustment member is configured as a solid body. Therefore, in the above-mentioned axial gap motor, even if the adjustment member is configured as a solid body, an increase in mechanical loss can be suppressed.

[0026] (6) In any of the axial gap motors described in (1) to (5), the stator may include a yoke formed in the shape of an annular plate, a stator core having a plurality of teeth protruding from the yoke, and a coil arranged on each of the plurality of teeth, and the stator core may be fixed to the first plane.

[0027] The axial gap motor is excellent in assembly precision as a double stator / single rotor type or a single stator / single rotor type motor.

[0028] (7) In the axial gap motor of (6), the stator core may be formed of a powder compact.

[0029] The axial gap motor described above has excellent assembly precision even when it includes a stator core made of a powder compact, which has lower dimensional precision than a stator core made of electromagnetic steel sheets.

[0030] (8) In the axial gap motor according to any one of (1) to (6), the number of the stators and the number of the rotors may be one each.

[0031] The axial gap motor is a single stator / single rotor type, and is excellent in assembly precision.

[0032] (9) A method for manufacturing an axial gap motor according to one aspect of the present disclosure includes a step of preparing parts for an axial gap motor, and a step of assembling the parts, wherein the parts include: a rotor; a stator; a shaft that is the rotation axis of the rotor; a bearing that rotatably supports the shaft; a case having a first plane on which the stator is placed; and an adjustment member that is screwed to the case to support the bearing, wherein the stator has a stator core having a yoke and a plurality of teeth, and a coil disposed on each of the plurality of teeth, and in the step of assembling the parts, the adjustment member is rotated relative to the case to raise and lower the shaft via the bearing, thereby setting the length of the gap between the rotor and the stator to a designed length, and the amount of rotation of the adjustment member is determined based on the value of the induced voltage generated in the coil.

[0033] In the above-described manufacturing method for an axial gap motor, the shaft can be raised and lowered using an adjustment member, thereby adjusting the rotor position. Therefore, in the above-described manufacturing method for an axial gap motor, the gap length can be set to the designed length by assembling the parts only once. Therefore, the above-described manufacturing method for an axial gap motor is excellent in manufacturability for an axial gap motor with excellent assembly precision, even without using a shim.

[0034] Details of the embodiments of the present disclosure Details of the embodiments of the present disclosure are described below. The same reference numerals in the drawings indicate the same items.

[0035] <<Embodiment 1>> [Axial Gap Motor] An axial gap motor 1 of embodiment 1 will be described with reference to Figures 1 to 5. Figure 1 is a cross-sectional view of the axial gap motor 1 cut along a plane parallel to the axial direction of the shaft 4. Figure 1 illustrates an axial gap motor 1 of a single stator / single rotor type. The single stator / single rotor type axial gap motor 1 is a motor in which there is one stator 2 and one rotor 3. The axial gap motor 1 is a motor in which the stator 2 and rotor 3 face each other with a gap in the axial direction of the shaft 4.

[0036] The axial gap motor 1 of this embodiment includes a stator 2, a rotor 3, a shaft 4, a first bearing 51, and a case 7. In the axial gap motor 1, the stator 2, rotor 3, and shaft 4 are housed within the case 7. The stator 2 and rotor 3 within the case 7 face each other with a gap in the axial direction of the shaft 4. The length of this gap along the axial direction satisfies the design length G1. The design length G1 is a target value for the design gap length determined based on the specifications of the axial gap motor 1. The design length G1 has a certain tolerance. One of the features of the axial gap motor 1 of this embodiment is that it includes an adjustment member 6 that is threadedly connected to the case 7.

[0037] 1, the stator 2 is disposed on the first plane 71f of the case 7. The stator 2 includes a stator core 21 and a plurality of coils 25. As shown in FIG.

[0038] (Stator Core) The stator core 21 includes a circular disk-shaped yoke 22 and a plurality of columnar teeth 23 .

[0039] <Yoke> The yoke 22 magnetically couples adjacent teeth 23 among the teeth 23 arranged in the circumferential direction of the yoke 22. As shown in FIG. 2 , the yoke 22 has a planar first surface 22f, a planar second surface 22s, an outer peripheral surface, and an inner peripheral surface. The first surface 22f and the second surface 22s connect the outer peripheral surface and the inner peripheral surface. The first surface 22f is in contact with the first plane 71f. The second surface 22s is a surface connected to the side surface of the tooth 23.

[0040] <Teeth> As shown in FIG. 1, the teeth 23 are provided with coils 25. There are a plurality of teeth 23. The teeth 23 are arranged at predetermined intervals in the circumferential direction of the yoke 22. The teeth 23 protrude perpendicular to the second surface 22s of the yoke 22 shown in FIG. 2. In this embodiment, the teeth 23 and the yoke 22 are formed as an integrated powder compact. The teeth 23 have the same shape and size. The teeth 23 are shaped like a rectangular pillar or a cylinder. Each tooth 23 has a side surface and an end surface 23a. The side surface is a surface that is connected to the second surface 22s of the yoke 22. The end surface 23a is a surface that is connected to the side surface. The end surface 23a faces a magnet 35 of the rotor 3, which will be described later.

[0041] <Hole> As shown in FIG. 1 , the stator core 21 has a hole. A fastening member 91 is provided in the hole. The fastening member 91 fixes the stator core 21 to the first plane 71f. The fastening member 91 prevents misalignment between the stator 2 and the first plane 71f. An example of the fastening member 91 is a screw or a bolt. The hole is formed from the first plane 22f to the middle of the tooth 23. The number of holes may be less than the number of the teeth 23 or may be the same as the number of the teeth 23.

[0042] <Constituent Materials> The powder compact that constitutes the stator core 21 is composed of an aggregate of a plurality of coated particles 24 shown in Fig. 4. Each coated particle 24 has metal particles 241 and an insulating coating 242.

[0043] Metal Particles The metal particles 241 are made of a soft magnetic material, such as pure iron or an iron-based alloy.

[0044] Pure iron has a purity of 99% or more. That is, pure iron has an iron (Fe) content of 99% by mass or more. The saturation magnetic flux density of pure iron is higher than that of iron-based alloys. Therefore, if the metal particles 241 of the powder compact are made of pure iron, the saturation magnetic flux density of the powder compact is likely to be improved. Furthermore, the formability of pure iron is superior to that of iron-based alloys. Therefore, if the metal particles 241 of the powder compact are made of pure iron, the relative density of the powder compact is likely to be high.

[0045] An iron-based alloy contains additive elements, with the remainder consisting of Fe and unavoidable impurities. The iron-based alloy contains the largest amount of Fe. The iron-based alloy is, for example, at least one selected from the group consisting of an Fe—Si (silicon)-based alloy, an Fe—Al (aluminum)-based alloy, an Fe—Si—Al-based alloy, and an Fe—Ni (nickel)-based alloy. An example of an Fe—Si-based alloy is silicon steel. An example of an Fe—Si—Al-based alloy is sendust. An example of an Fe—Ni-based alloy is permalloy. The electrical resistance of an iron-based alloy is higher than that of pure iron. Therefore, iron-based alloys tend to reduce iron losses such as eddy current losses. Therefore, if the metal particles 241 of the powder compact are composed of an iron-based alloy, the loss of the powder compact is likely to be reduced. The powder compact may contain both metal particles 241 composed of pure iron and metal particles 241 composed of an iron-based alloy.

[0046] Insulating Coating The insulating coating 242 covers the metal particles 241. The insulating coating 242 can reduce iron loss such as eddy current loss. A powder compact including the insulating coating 242 is more likely to reduce loss. The material of the insulating coating 242 is, for example, an oxide. Examples of oxides are phosphate, silica, magnesium oxide, or aluminum oxide. Phosphate has excellent adhesion to the metal particles 241 and also excellent deformability. Therefore, if the insulating coating 242 is made of phosphate, the insulating coating 242 is more likely to deform in response to the deformation of the metal particles 241 during the process of producing the powder compact. Therefore, the insulating coating 242 is less likely to be damaged. Because the insulating coating 242 is less likely to be damaged, the loss of the powder compact is more likely to be reduced.

[0047] <Relative Density> The relative density of the powder compact may be 90% or more. A powder compact with a relative density of 90% or more is likely to have improved saturation magnetic flux density. A powder compact with a relative density of 90% or more is likely to have improved mechanical properties such as strength. The relative density may be 93% or more, or even 95% or more. The relative density may be 99% or less. A powder compact with a relative density of 99% is likely to have a stable induced voltage value measured in the manufacturing method described below.

[0048] The "relative density of a powder compact" refers to the ratio (%) of the density of an actual powder compact to the true density of the powder compact. That is, the relative density of a powder compact can be calculated by [(density of actual powder compact / true density of powder compact) × 100]. The density of an actual powder compact can be calculated by immersing the powder compact in oil to impregnate it with oil and calculating [oil-impregnated density × (mass of powder compact before oil impregnation / mass of powder compact after oil impregnation)]. The oil-impregnated density is (mass of powder compact after oil impregnation / volume of powder compact after oil impregnation). That is, the density of an actual powder compact can be calculated by (mass of powder compact before oil impregnation / volume of powder compact after oil impregnation). The volume of a powder compact after oil impregnation can typically be measured by the liquid displacement method. The true density of a powder compact is the theoretical density assuming no voids are present inside.

[0049] (Coil) Each coil 25 has a cylindrical portion. The cylindrical portion is formed by winding a wire in a spiral shape. The coil 25 in this embodiment is an edgewise wound coil. A coated rectangular wire is used for the winding of the coil 25. Each coil 25 is arranged on the outer periphery of the side surface of the tooth 23. The cross-sectional shape of the cylindrical portion of each coil 25 corresponds to the cross-sectional shape of the tooth 23, for example. The axial length of the cylindrical portion is slightly shorter than the length of the tooth 23. Note that FIG. 1 shows only the cylindrical portion, and both ends of the winding are not shown.

[0050] [Rotor] The rotor 3 is provided with a gap between it and the stator 2. The rotor 3 includes a rotor body 31 and at least one magnet 35.

[0051] (Rotor body) The rotor body 31 is rotatably supported relative to the case 7 by the shaft 4. The rotor body 31 is an annular member. A through hole is provided in the center of the rotor body 31. A third shaft portion 43 of the shaft 4, which will be described later, is provided in this through hole. In this embodiment, the rotor body 31 and the shaft 4 are combined by press-fitting the shaft 4 into the through hole. This press-fitting tends to reduce runout of the rotor 3. The position of the rotor body 31 along the axial direction of the shaft 4 is determined by the rotor body 31 abutting against a second end face 42s of a second shaft portion 42, which will be described later.

[0052] As shown in FIG. 2 , the rotor body 31 has a first surface 31f, a second surface 31s, an inner circumferential surface, and an outer circumferential surface. The first surface 31f and the second surface 31s connect the inner circumferential surface and the outer circumferential surface. The first surface 31f faces the stator 2. The second surface 31s faces the second bearing 55 shown in FIG. 1 . The second bearing 55 will be described later. In this embodiment, a recess 32 is provided in the first surface 31f. The recess 32 opens toward the stator 2. A magnet 35 is fixed to the bottom surface 32a of the recess 32. The inner circumferential surface of the rotor body 31 contacts the third shaft portion 43 of the shaft 4. As shown in FIG. 1 , the outer circumferential surface of the rotor body 31 does not contact the inner circumferential surface of the peripheral wall portion 73 of the case 7. A gap is provided between the outer circumferential surface of the rotor body 31 and the inner circumferential surface of the peripheral wall portion 73 of the case 7.

[0053] (Magnet) The magnet 35 is fixed to the rotor body 31. As shown in FIG. 2, adhesive 38 is used to fix the magnet 35. The number of magnets 35 may be one or more. If there is one magnet 35, the number of parts is fewer and the rotor 3 is easier to manufacture than when there are multiple magnets 35. This makes it easier to improve the manufacturability of the axial gap motor 1. Furthermore, it is easier to manufacture an axial gap motor 1 with excellent assembly precision.

[0054] When there is one magnet 35, the magnet 35 has an annular shape. The south and north poles of each magnet 35 are arranged alternately in the circumferential direction. When there are multiple magnets 35, the specific number of magnets 35 is the same as the number of teeth 23. The multiple magnets 35 are arranged at equal intervals in the circumferential direction of the rotor body 31. Each magnet 35 has, for example, a flat plate shape. The planar shape of each magnet 35 is, for example, the same as the planar shape of the end surface 23 a of the tooth 23. Each magnet 35 is magnetized in the axial direction of the rotation shaft of the rotor 3. The magnets 35 adjacent to each other in the circumferential direction of the rotor body 31 have opposite magnetization directions. The rotating magnetic field generated by the stator 2 repeatedly attracts and repels the magnet 35 to and from each tooth 23, causing the rotor 3 to rotate.

[0055] The magnet 35 is a permanent magnet. Specific examples of the permanent magnet include a ferrite magnet, a neodymium magnet, a samarium-cobalt magnet, and a bonded magnet. Neodymium magnets and samarium-cobalt magnets have particularly strong magnetic forces.

[0056] [Shaft] The shaft 4 is the rotation axis of the rotor 3. The shaft 4 is formed of a solid round bar. As shown in FIG. 1 , the shaft 4 has multiple shaft portions with different outer diameters. The multiple shaft portions are integrally formed. The shaft 4 of this embodiment has, in order from the first plate portion 71 toward the second plate portion 72 of the case 7, a first shaft portion 41, a second shaft portion 42, a third shaft portion 43, a fourth shaft portion 44, and a fifth shaft portion 45.

[0057] As shown in Fig. 1, the first shaft portion 41 is provided inside the first bearing 51. The outer peripheral surface of the first shaft portion 41 contacts the inner peripheral surface of the inner race 52 of the first bearing 51 as shown in Fig. 2.

[0058] As shown in Fig. 1, the second shaft portion 42 has a diameter larger than the diameter of the first shaft portion 41. As shown in Fig. 2, the second shaft portion 42 has a first end face 42f and a second end face 42s. The first end face 42f is in contact with a first end face 52f of the inner race 52. The first end face 42f is not in contact with the outer race 53 of the first bearing 51. The second end face 42s is in contact with the first surface 31f.

[0059] As shown in Fig. 1, the third shaft portion 43 is provided in a through hole of the rotor body 31. As shown in Fig. 2, the outer peripheral surface of the third shaft portion 43 contacts the inner peripheral surface of the rotor body 31. As shown in Fig. 1, the third shaft portion 43 has a diameter smaller than the diameter of the second shaft portion 42. As shown in Fig. 2, the third shaft portion 43 has an end face 43a. The end face 43a contacts a first end face of the inner race 56 of the second bearing 55.

[0060] 1, the fourth shaft portion 44 is provided in the second bearing 55. The outer peripheral surface of the fourth shaft portion 44 contacts the inner peripheral surface of the inner race 56. The fourth shaft portion 44 has a diameter smaller than the diameter of the third shaft portion 43.

[0061] The fifth shaft portion 45 is disposed within a through hole 72h. The through hole 72h is disposed in a second plate portion 72, which will be described later. The outer peripheral surface of the fifth shaft portion 45 does not contact the inner peripheral surface of the second plate portion 72. The fifth shaft portion 45 has a diameter smaller than the diameter of the fourth shaft portion 44.

[0062] [First Bearing and Second Bearing] The first bearing 51 and the second bearing 55 rotatably support the shaft 4. The first bearing 51 is attached to the first shaft portion 41. The second bearing 55 is attached to the fourth shaft portion 44. The first bearing 51 and the second bearing 55 may have the same configuration as each other, or may have different configurations.

[0063] 2 and 3, the first bearing 51 is a radial bearing having an inner race 52 and an outer race 53. The radial bearing of this embodiment is a ball bearing in which balls 54 are disposed between the inner race 52 and the outer race 53. The inner peripheral surface of the inner race 52 contacts the outer peripheral surface of the first shaft portion 41. The outer peripheral surface of the outer race 53 contacts a first protrusion 71a, which will be described later.

[0064] The inner race 52 has a first end face 52f and a second end face 52s. The outer race 53 has a first end face 53f and a second end face 53s. The first end face 52f contacts the first end face 42f. The second end face 52s does not contact the case 7 or the adjusting member 6 (described later). In this embodiment, the second end face 52s contacts a fixing member (not shown). This fixing member mechanically fixes the first bearing 51 and the first shaft portion 41. An example of this fixing member is a retaining ring or a shaft nut. When a shaft nut is used as the fixing member, it is preferable to form a threaded portion on the outer peripheral surface of the first shaft portion 41. This fixing member does not have to be used. In this case, the inner race 52 and the first shaft portion 41 are fixed by fitting them together. The first end face 53f does not contact the shaft 4. The second end face 53s contacts the adjusting member 6.

[0065] 2 shows an example in which the first end surface 52f and the first end surface 53f are not misaligned along the axial direction of the first bearing 51. FIG. 3 shows an example in which the first end surface 52f and the first end surface 53f are misaligned along the axial direction of the first bearing 51. The first end surface 52f and the first end surface 53f may also be misaligned along the axial direction of the first bearing 51.

[0066] The misalignment between the first end surface 52f and the first end surface 53f is caused by a load acting on the inner race 52 due to the weight of the shaft 4 and the rotor 3, and a load acting on the inner race 52 due to the attractive force of the magnet 35 toward the stator 2. The misalignment is further caused by a load acting on the inner race 52 due to the weight of the second bearing 55, and a load acting on the inner race 52 due to the pressing force of the elastic member 8 pressing the second bearing 55 toward the first bearing 51.

[0067] The inner race 52 is primarily subjected to loads due to the weight of the shaft 4 and the rotor 3 and the attractive force of the magnet 35 toward the stator 2. The inner race 52 is further subjected to at least one of the following loads: the weight of the second bearing 55 and the pressing force of the elastic member 8 pressing the second bearing 55 toward the first bearing 51. Depending on the magnitude of the load, the first end face 52f may be misaligned with respect to the first end face 53f. In particular, the misalignment of the first end face 52f is largely influenced by the attractive force of the magnet 35. That is, the stronger the magnetic force of the magnet 35, the greater the misalignment of the first end face 52f.

[0068] The second bearing 55 has the same configuration as the first bearing 51. That is, as shown in FIGS. 2 and 3 , the second bearing 55 is a radial bearing having an inner race 56 and an outer race 57. The inner peripheral surface of the inner race 56 contacts the outer peripheral surface of the fourth shaft portion 44. The outer peripheral surface of the outer race 57 contacts the inner peripheral surface of the recess 72a. The recess 72a is provided in the second plate portion 72. The inner race 56 and the outer race 57 each have a first end face and a second end face. The first end face of the inner race 56 contacts the end face 43a. The second end face of the inner race 56 does not contact the elastic member 8 or the case 7, which will be described later. The second end face of the inner race 56 may or may not contact a fixed member similar to the first bearing 51. This is because the elastic member 8 presses the outer race 57 toward the rotor 3. The first end face of the outer race 57 does not contact the rotor 3 or the shaft 4. The second end surface of the outer race 57 is in contact with the elastic member 8 shown in FIG.

[0069] Unlike this embodiment, at least one of the first bearing 51 and the second bearing 55 may be an angular ball bearing.

[0070] [Elastic Member] The elastic member 8 presses the second bearing 55 in a direction toward the rotor 3. The elastic member 8 makes it easy to suppress rattle between the second protrusion 71b and the adjustment member 6. The elastic member 8 is disposed between the outer race 57 and the bottom of the recess 72a. An example of the elastic member 8 is a spring washer, a disc spring washer, a wave washer, or a rubber O-ring.

[0071] [Case] ​​The case 7 accommodates the stator 2, the rotor 3, a portion of the shaft 4, the first bearing 51, and the second bearing 55. The case 7 includes a first plate portion 71, a second plate portion 72, and a peripheral wall portion 73.

[0072] In this embodiment, the peripheral wall portion 73 and the second plate portion 72 are integrally configured. In this embodiment, the peripheral wall portion 73 and the first plate portion 71 are separate. Unlike this embodiment, the peripheral wall portion 73 and the first plate portion 71 may be integrally configured, and the peripheral wall portion 73 and the second plate portion 72 may be separate. Also, unlike this embodiment, the peripheral wall portion 73, the first plate portion 71, and the second plate portion 72 may be separate. In this embodiment, the peripheral wall portion 73 and the first plate portion 71 are fixed to each other by fastening members 92. Similar to the fastening members 91, an example of the fastening members 92 is a screw or a bolt.

[0073] The peripheral wall portion 73 surrounds the outer peripheries of the stator 2 and the rotor 3. A hole is provided in the end surface of the peripheral wall portion 73. A fastening member 92 is provided in this hole.

[0074] The first plate portion 71 has a first flat surface 71f, a second flat surface 71s, a first protruding portion 71a, a second protruding portion 71b, a first through hole, a second through hole, and a third through hole.

[0075] The first plane 71f is provided on the inside of the case 7. The stator 2 is disposed on the first plane 71f. The second plane 71s is provided on the outside of the case 7. The second plane 71s is provided on the opposite side to the first plane 71f.

[0076] The first protrusion 71a is provided between the stator 2 and the first bearing 51. The shape of the first protrusion 71a is, for example, cylindrical. The first protrusion 71a is connected to a first flat surface 71f. The outer peripheral surface of the first protrusion 71a may or may not be in contact with the inner peripheral surface of the yoke 22. The inner peripheral surface of the first protrusion 71a is connected to the inner peripheral surface of the second protrusion 71b. The inner peripheral surface of the first protrusion 71a is in contact with the outer peripheral surface of the outer race 53. The first protrusion 71a can be used to position the first bearing 51.

[0077] The second protruding portion 71b has a cylindrical shape. The outer peripheral surface of the second protruding portion 71b is connected to the second flat surface 71s. The inner peripheral surface of the second protruding portion 71b is connected to the inner peripheral surface of the first protruding portion 71a. As shown in FIG. 5 , a threaded portion 711 is provided on the inner peripheral surface of the second protruding portion 71b. The adjustment member 6 is threadedly coupled to the inner peripheral surface of the second protruding portion 71b.

[0078] A part of the first shaft portion 41 is provided in the first through hole. A fastening member 91 is provided in the second through hole. The second through hole is provided in a position corresponding to the hole portion of the stator core 21. A fastening member 92 is provided in the third through hole. The third through hole is provided in a position corresponding to the hole portion of the peripheral wall portion 73.

[0079] The second plate portion 72 has a recess 72a in its center. A through hole 72h is provided at the bottom of the recess 72a. The fifth shaft portion 45 is provided within the through hole 72h. The inner diameter of the through hole 72h is larger than the outer diameter of the fifth shaft portion 45. Therefore, the shaft 4 rotates without contact between the inner circumferential surface of the through hole 72h and the fourth shaft portion 44.

[0080] [Adjusting Member] The adjusting member 6 supports the first bearing 51. The adjusting member 6 in this embodiment is cylindrical. The inner dimension of the adjusting member 6 in this embodiment is greater than the outer diameter of the inner race 52 and is equal to or smaller than the inner diameter of the outer race 53. The inner dimension is the diameter of the inscribed circle of the inner peripheral surface of the adjusting member 6.

[0081] The adjustment member 6 has a first end face 61f, a second end face 61s, an inner circumferential surface, and an outer circumferential surface. The first end face 61f is in direct contact with the second end face 53s. The first end face 61f is not in contact with the second end face 52s. This can suppress an increase in mechanical loss. This is because the adjustment member 6 is not in contact with the inner race 52, so friction does not increase. The second end face 61s is not in contact with the first end face 61f or the first plate portion 71.

[0082] A threaded portion 611 is provided on the outer peripheral surface of the adjustment member 6. The outer peripheral surface of the adjustment member 6 is threadedly coupled to the inner peripheral surface of the second protrusion 71b. The pitch of the threaded portion 611 can be selected as appropriate. The smaller the pitch, the easier it is to finely adjust the gap length using the adjustment member 6 during the manufacturing process. The pitch may be, for example, 2.5 mm or less. The pitch may further be 1.5 mm or less, particularly 1.0 mm or less. The lower limit of the pitch may be, for example, 0.5 mm. That is, the pitch may be 0.5 mm or more and 2.5 mm or less, further 0.5 mm or more and 1.5 mm or less, particularly 0.5 mm or more and 1.0 mm or less.

[0083] A tool is fitted onto the inner circumferential surface of the adjustment member 6. The tool rotates the adjustment member 6 during the manufacturing process. The inner circumferential surface of the adjustment member 6 is configured in a polygonal shape. If the inner circumferential surface of the adjustment member 6 is configured in a hexagonal shape, for example, a hexagonal wrench can be used as the tool.

[0084] The axial gap motor 1 of this embodiment has excellent assembly precision. By rotating the adjustment member 6 relative to the second protrusion 71b during the manufacturing process, the first bearing 51 can be moved in the axial direction of the shaft 4. Because the first end face 52f and the first end face 42f are in contact with each other, the axial movement of the first bearing 51 can move the shaft 4 in the axial direction. Because the second end face 42s and the first face 31f are in contact with each other, the axial movement of the shaft 4 can move the rotor 3 in the axial direction. In other words, the rotor 3 can be easily moved to a position where the gap length is the designed length. Because the adjustment member 6 and the second protrusion 71b are threadedly coupled, the rotor 3 cannot move in the axial direction unless the adjustment member 6 is rotated. Therefore, the rotor 3 is positioned where the gap length is the designed length G1.

[0085] [Method of Manufacturing Axial Gap Motor] A method of manufacturing the axial gap motor of embodiment 1 will be described mainly with reference to Figures 6 to 8. The method of manufacturing the axial gap motor of this embodiment includes process A and process B. Process A prepares parts for the axial gap motor. Process B assembles the parts.

[0086] [Step A] The parts prepared in step A are the parts of the axial gap motor 1 described above with reference to Fig. 1. In this embodiment, the parts include the stator 2, the rotor 3, the shaft 4, the first bearing 51, the second bearing 55, the adjustment member 6, the case 7, the elastic member 8, the fastening member 91, and the fastening member 92.

[0087] [Process B] In process B, in which the parts are assembled, each member is fixed in a predetermined position. By going through process B, the axial gap motor 1 as shown in Fig. 1 is manufactured. The parts are assembled, for example, in the following order from process B1 to process B7.

[0088] In step B1, the second protruding portion 71b of the first plate portion 71 is screw-coupled to the adjustment member 6. By rotating the adjustment member 6 relative to the second protruding portion 71b, it is possible to adjust the position of the first end surface 61f of the adjustment member 6. The position of the first end surface 61f will be described later.

[0089] In step B2, the first plate portion 71 and the stator 2 are fixed together, and the first bearing 51 is positioned. The order of the fixing and positioning is not important. The fixing is performed as follows: The stator 2 is positioned on the first flat surface 71f of the first plate portion 71. Next, the fastening member 91 is tightened into the second through hole of the first plate portion 71 and the hole portion of the stator 2. The positioning is performed as follows: The first bearing 51 is fitted into the first protrusion 71a of the first plate portion 71. Then, as shown in FIG. 2 , the second end surface 53s of the outer race 53 of the first bearing 51 is brought into contact with the first end surface 61f of the adjustment member 6.

[0090] In step B3, the first shaft portion 41 of the shaft 4 is placed in the first bearing 51. A rotor assembly in which the rotor 3 and shaft 4 are combined is prepared in advance. In step B3, the first shaft portion 41 of the rotor assembly is placed in the first bearing 51. In this case, step B4 is performed without going through step B31. If the rotor 3 and shaft 4 are prepared without being combined without preparing a rotor assembly, step B31 is performed before step B4. In step B31, the rotor 3 is fitted onto the shaft 4 in a state in which the first shaft portion 41 is placed in the first bearing 51.

[0091] In step B4, the second bearing 55 is fitted onto the fourth shaft portion 44 of the shaft 4.

[0092] In step B5, the elastic member 8 is placed on the second bearing 55.

[0093] In step B6, the through hole 72h of the second plate portion 72 is fitted onto the fifth shaft portion 45 of the shaft 4, and the end face of the peripheral wall portion 73 is butted against the first plate portion 71. Then, the first plate portion 71 and the peripheral wall portion 73 are fixed together by fastening members 92. The fastening members 92 are provided in the third through hole of the first plate portion 71 and the hole portion of the peripheral wall portion 73.

[0094] In step B1, the position of the first end face 61f of the adjustment member 6 is set so that "gap length > design length G1" or "gap length < design length G1" after step B6. Fig. 6 shows a state in which the adjustment member 6 is set at a position where gap length > design length G1.

[0095] In step B7, the length of the gap is set to the design length G1. In step B7, steps 1 and 2 are performed in this order.

[0096] In step 1, the adjustment member 6 is rotated relative to the second protrusion 71b. A tool (not shown) is fitted into the adjustment member 6. The tool is rotated. As indicated by the arc-shaped white arrow in FIG. 6 , the rotation of the tool rotates the adjustment member 6 relative to the second protrusion 71b. As shown in FIG. 2 , the first end face 61f and the second end face 53s are in contact with each other, and therefore the first bearing 51 is moved in the axial direction of the shaft 4 by the rotation of the adjustment member 6. The first end face 52f and the first end face 42f are in contact with each other, and therefore the axial movement of the first bearing 51 is moved in the axial direction of the shaft 4 by the rotation of the adjustment member 6. The first face 31f and the second end face 42s are in contact with each other, and therefore the axial movement of the shaft 4 is moved in the axial direction of the shaft 4 by the rotation of the adjustment member 6. The rotor 3 is moved in the axial direction of the shaft 4 by the rotation of the rotor 3 in the axial direction. The gap length between the end face 23a and the first end face 35f changes due to the axial movement of the rotor 3. The amount of rotation of the adjustment member 6 in step 1 can be selected as appropriate.

[0097] The amount of rotation of the adjustment member 6 is determined based on the induced voltage value generated in the coil 25. The induced voltage value can be measured by a voltmeter 110. The induced voltage value decreases as the gap length increases and increases as the gap length decreases. The target value of the designed induced voltage value determined based on the specifications of the axial gap motor 1 is set as the design voltage value. The design voltage value has a certain tolerance range. The gap length based on this design voltage value is the design length G1. In other words, if the measured induced voltage value meets the design voltage value, it can be determined that the gap length meets the design length G1.

[0098] In step 2, the induced voltage value is measured. The measurement of the induced voltage value may be performed after the adjustment member 6 has finished rotating, or may be performed while the adjustment member 6 is rotating. The induced voltage value is measured without exciting the coil 25.

[0099] Steps 1 and 2 are repeated until the measured induced voltage value satisfies the design voltage value.

[0100] The graphs in FIGS. 7 and 8 show an example in which steps 1 and 2 were performed four times. The induced voltage value (V) on the left vertical axis in FIGS. 7 and 8 is the induced voltage value when the rotor 3 was moved to a predetermined position by step 1. The gap length on the right vertical axis in FIGS. 7 and 8 is the gap length when the rotor 3 was moved to a predetermined position by step 1. The number of times on the horizontal axis in FIGS. 7 and 8 is the number of times steps 1 and 2 were performed. FIG. 7 shows an example in which steps 1 and 2 were repeated from a state in which the adjustment member 6 was positioned so that "gap length > design length G1" as shown in FIG. 6, gradually shortening the gap length to the design length G1. FIG. 8, although not shown, shows an example in which steps 1 and 2 were repeated from a state in which the adjustment member 6 was positioned so that "gap length < design length G1" and gradually increasing the gap length to the design length G1.

[0101] In FIG. 7 , the measured induced voltage value increases with each increase in the number of times that Procedure 1 is performed. This is because the gap length is gradually shortened. On the other hand, in FIG. 8 , the measured induced voltage value decreases with each increase in the number of times that Procedure 1 is performed. This is because the gap length is gradually lengthened. As shown in FIGS. 7 and 8 , when Procedure 1 and Procedure 2 are performed one to three times, the induced voltage value does not fall within the range of the design voltage value. By performing Procedure 1 and Procedure 2 four times, the induced voltage value falls within the range of the design voltage value. That is, in the example shown in FIGS. 7 and 8 , by performing Procedure 1 and Procedure 2 four times, the gap length becomes the design length G1.

[0102] When the induced voltage value is measured while rotating the adjustment member 6, the induced voltage value does not increase or decrease stepwise as in FIG. 7 or FIG. 8, but increases or decreases continuously.

[0103] Step B7 may be performed between steps B4 and B5.

[0104] The manufacturing method for the axial gap motor of this embodiment can adjust the position of the rotor 3 using the adjustment member 6 after assembling the parts. Alternatively, the manufacturing method for the axial gap motor of this embodiment can adjust the position of the rotor 3 using the adjustment member 6 while assembling the parts. Therefore, the manufacturing method for the axial gap motor of this embodiment can set the gap length to the designed length G1 by assembling the parts only once. Therefore, the manufacturing method for the axial gap motor of this embodiment is excellent in manufacturability of the axial gap motor 1, which has excellent assembly precision, even without using a shim.

[0105] 9 and 10, an axial gap motor according to a modified example will be described. The axial gap motor according to this example uses a circuit board 120, a sensor 130, a magnet 140, and a cover 160, as shown in FIG.

[0106] The circuit board 120 is used to pass current of an appropriate magnitude at an appropriate timing to each coil 25 when the axial gap motor is in use. The circuit board 120 is attached to the second plane 71s. The circuit board 120 has an annular shape. As shown in FIG. 10 , the circuit board 120 has a waveform conversion element group 121, a waveform control IC (Integrated Circuit) 122, and a phase detection circuit 123.

[0107] The waveform conversion element group 121 is connected to a power supply (not shown) and the coil 25 shown in FIG. 9 . The waveform conversion element group 121 converts the waveform of the power supply into an arbitrary drive waveform. Examples of the drive waveform include three-phase sine, square, full-wave, and half-wave waveforms. The power supply is a DC power supply or a single-phase AC power supply. The waveform control IC 122 receives signals indicating the rotation speed of the rotor 3 and the torque of the axial gap motor 1 from an external device and controls the amplitude and frequency of the waveform of the current or voltage flowing to the coil 25. Examples of external devices include a resolver, a Hall sensor, and a rotary encoder. The waveform control IC 122 is connected to the waveform conversion element group 121 and a phase detection circuit 123. The phase detection circuit 123 detects the rotational position of the rotor 3 and controls the phase timing of the waveform of the current or voltage flowing to the coil 25. The phase detection circuit 123 is connected to a sensor 130.

[0108] The sensor 130 is provided to face the magnet 140. An example of the type of the sensor 130 is a Hall sensor.

[0109] The magnet 140 is attached to the outer peripheral surface of a jig 141. The jig 141 is attached to the end face of the first shaft portion 41. Therefore, when the shaft 4 rotates, the jig 141 rotates. The shape of the jig 141 is cylindrical. The shape of the magnet 140 is cylindrical, and the south poles and north poles of the magnet 140 are arranged alternately in the circumferential direction.

[0110] The cover 160 protects the circuit board 120. The cover 160 includes a plate portion 161 and a peripheral wall portion 162. The plate portion 161 and the peripheral wall portion 162 are integrally formed. The plate portion 161 is disposed facing the second plane 71s across the circuit board 120. The plate portion 161 covers the circuit board 120. The plate portion 161 has an annular plate shape. A through-hole is provided in the center of the plate portion 161. The inner diameter of the plate portion 161 is greater than the inner diameter of the adjustment member 6. This makes it easy to insert a tool into the through-hole of the plate portion 161. This makes it easy to rotate the adjustment member 6 with the tool. The peripheral wall portion 162 has a cylindrical shape. The peripheral wall portion 162 is provided outside the outer periphery of the circuit board 120. The peripheral wall portion 162 is attached to the second plane 71s.

[0111] The axial gap motor of this example, like the first embodiment, has excellent assembly precision even without using shims.

[0112] Second Embodiment As shown in FIG. 11 , the axial gap motor of the second embodiment has a washer 65. The washer 65 is disposed between the second end face 53s and the first end face 61f. The inner diameter of the washer 65 is greater than the outer diameter of the inner race 52 and less than or equal to the inner diameter of the outer race 53. The washer 65 can make it easier for the adjustment member 6 to support the outer race 53. Examples of types of washer 65 include a flat washer or a disc spring washer. The flat washer improves the fit between the second end face 53s and the first end face 61f. The disc spring washer makes it easier to prevent the adjustment member 6 from loosening relative to the second protrusion 71b.

[0113] The shape of the adjustment member 6 in this embodiment is cylindrical, as in embodiment 1. The lower limit of the inner dimension of the cylindrical adjustment member 6 can be equal to or larger than the inner diameter of the inner race 52 and equal to or smaller than the outer diameter of the inner race 52. This is because the washer 65 prevents contact between the adjustment member 6 and the inner race 52. Therefore, the axial gap motor of this embodiment can suppress an increase in mechanical loss even if the inner dimension of the adjustment member 6 is equal to or larger than the inner diameter of the inner race 52 and equal to or smaller than the outer diameter of the inner race 52.

[0114] Unlike the present embodiment, the shape of the adjustment member 6 can also be cylindrical. This is because the washer 65 prevents contact between the adjustment member 6, which is a solid body such as a cylindrical body, and the inner race 52. Therefore, the axial gap motor of this embodiment can suppress an increase in mechanical loss even if the adjustment member 6 is cylindrical. The cylindrical adjustment member 6 has a first recess. A tool is fitted into the first recess. The first recess is provided on the second end surface of the adjustment member 6. As shown in FIG. 11 , when the first shaft portion 41 protrudes beyond the second end surface 52s, the cylindrical adjustment member 6 has a second recess. The first shaft portion 41 is disposed in the second recess. The second recess is provided on the first end surface of the adjustment member 6. The inner dimension of the second recess is large enough so that the inner circumferential surface of the second recess does not come into contact with the outer circumferential surface of the first shaft portion 41. The inner dimension is the diameter of an inscribed circle of the inner circumferential surface of the second recess. The depth of the second recess is such that the bottom of the second recess does not come into contact with the end face of the first shaft portion 41. If the end face of the first shaft portion 41 and the second end face 52s are substantially flush with each other and the first shaft portion 41 does not come into contact with the cylindrical adjustment member 6, the second recess may not be provided.

[0115] The present invention is not limited to these examples, but is defined by the scope of the claims, and is intended to include all modifications within the meaning and scope of the claims.

[0116] For example, the yoke may be formed by joining a plurality of fan-shaped yoke pieces together in an annular shape. The number of teeth connected to each yoke piece may be one or more.

[0117] The axial gap motor may also be a double stator / single rotor type axial gap motor. A double stator / single rotor type axial gap motor is a motor with two stators and one rotor. In a double stator / single rotor type axial gap motor, one rotor is sandwiched between two stators.

[0118] 1 Axial gap motor 2 Stator 21 Stator core 22 Yoke, 22f First surface, 22s Second surface 23 Teeth, 23a End surface 24 Coating particles, 241 Metal particles 242 Insulating coating 25 Coil 3 Rotor 31 Rotor body, 31f First surface, 31s Second surface 32 Recess, 32a Bottom surface 35 Magnet, 35f First end surface 38 Adhesive 4 Shaft 41 First shaft portion 42 Second shaft portion, 42f First end surface, 42s Second end surface 43 Third shaft portion, 43a End surface 44 Fourth shaft portion, 45 Fifth shaft portion 51 First bearing 52 Inner race, 52f First end surface, 52s Second end surface 53 Outer race, 53f First end surface, 53s Second end surface 54 DESCRIPTION OF SYMBOLS Ball 55 Second bearing 56 Inner race, 57 Outer race 6 Adjustment member 61f First end face, 61s Second end face, 611 Threaded portion 65 Washer 7 Case 71 First plate portion, 71f First flat surface, 71s Second flat surface 71a First protrusion, 71b Second protrusion, 711 Threaded portion 72 Second plate portion, 72a Recess, 72h Through hole 73 Peripheral wall portion 8 Elastic member 91, 92 Fastening member 110 Voltmeter 120 Circuit board 121 Waveform conversion element group, 122 Waveform control IC, 123 Phase detection circuit 130 Sensor, 140 Magnet, 141 Jig 160 Cover, 161 Plate portion, 162 Peripheral wall portion A, B, C Area G1 Design length

Claims

1. A rotor, a stator disposed in a direction of a rotation axis of the rotor with a gap of a design length therebetween; A shaft that is a rotation axis of the rotor; a first bearing that rotatably supports the shaft; a second bearing that rotatably supports the shaft and is disposed opposite the first bearing with the rotor therebetween; a case having a first plane on which the stator is mounted; an adjustment member supporting the first bearing and for adjusting the length of the gap; the adjustment member has a thread that is threadably coupled to the case; The first bearing moves in the axial direction of the shaft by rotation of the adjustment member. Axial gap motor.

2. The axial gap motor according to claim 1 , wherein the pitch of the thread of the adjustment member is 2.5 mm or less.

3. An axial gap motor as described in claim 1 or claim 2, comprising an elastic member that presses the second bearing toward the first bearing.

4. the first bearing is a radial bearing having an inner race and an outer race; 3. The axial gap motor according to claim 1, wherein the adjustment member supports the outer race without contacting the inner race.

5. The axial gap motor according to claim 4 , further comprising a washer disposed between the outer race and the adjustment member.

6. The stator includes: a stator core having a yoke formed in a circular plate shape and a plurality of teeth protruding from the yoke; a coil disposed on each of the plurality of teeth, The axial gap motor according to claim 1 or 2, wherein the stator core is fixed to the first plane.

7. The axial gap motor according to claim 6 , wherein the stator core is made of a powder compact.

8. 3. The axial gap motor according to claim 1, wherein the number of the stators and the number of the rotors are one each.

9. preparing parts for an axial gap motor; and assembling the parts. The parts are: A rotor, A stator; A shaft that is a rotation axis of the rotor; A bearing that rotatably supports the shaft; a case having a first plane on which the stator is mounted; an adjustment member that is screwed to the case to support the bearing, The stator includes: a stator core having a yoke and a plurality of teeth; a coil disposed on each of the plurality of teeth, In the step of assembling the parts, the adjustment member is rotated relative to the case to raise and lower the shaft via the bearing, thereby setting the length of the gap between the rotor and the stator to a designed length; The amount of rotation of the adjustment member is determined based on the value of the induced voltage generated in the coil. A method for manufacturing an axial gap motor.