Magnetic gear transmission rotary electric machine and method of manufacturing stator

Abstract

A magnetic gear transmission rotary electric machine includes a housing, a stator having a stator core, a coil, and a stator magnet provided on an inner side of the stator core, a first rotor having a pole piece provided on an inner side of the stator, and a second rotor having a rotor core provided on an inner side of the first rotor and a plurality of rotor magnets provided on the rotor core. The stator core has a back yoke and a tooth that protrudes from the back yoke toward an inner side in a radial direction and is provided with a plurality of teeth at intervals in a circumferential direction. The stator magnet is installed on an end portion of the tooth on an inner side in the radial direction in the circumferential direction. A portion of the tooth in which the stator magnet is installed is divided to be detachable with respect to other portions in the stator core.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to a magnetic gear transmission rotary electric machine and a manufacturing method of a stator.

[0002] This application claims priority based on Japanese Patent Application No. 2020-010231 filed on January 24, 2020, and the content thereof is incorporated herein by reference. BACKGROUND

[0003] In the following Patent Literature 1, a magnetic gear transmission rotary electric machine in which a low-speed rotor (first rotor), a high-speed rotor (second rotor), and a stator can coaxially relatively rotate is disclosed.

[0004] In a case where the magnetic gear transmission rotary electric machine is used as a motor, for example, the high-speed rotor is rotated by a magnetic motive force of a coil provided to the stator, and thereby the low-speed rotor as an output shaft is rotated at a predetermined reduction ratio by a high-order harmonic magnetic flux.

[0005] In the magnetic gear transmission rotary electric machine, the stator has a stator core and a plurality of stator magnets provided to an inner peripheral side of the stator core. A specific example of the stator core for a general motor is disclosed in the following Patent Literature 2. The stator core has a back yoke in a ring shape and a plurality of teeth extending from the back yoke to the inner peripheral side. In addition, a structure in which the stator core is divided into a plurality of portions is shown in the following Patent Literature 2. More specifically, the stator core is formed by dividing the back yoke in the circumferential direction per 1 tooth.

[0006] PRIOR ART DOCUMENTS

[0007] PATENT LITERATURE

[0008] Patent Literature 1: Japanese Patent Application Publication No. 2014-163431

[0009] Patent Literature 2: Japanese Patent No. 5450189 SUMMARY

[0010] PROBLEMS TO BE SOLVED BY THE INVENTION

[0011] However, in the magnetic gear transmission rotary electric machine, the stator has a large diameter of several m, for example. If the back yoke is divided per tooth as described above, a slight gap is generated at the division surface, and thus it is difficult to maintain the circularity of the back yoke at the time of assembly. Further, in the magnetic gear transmission rotary electric machine, after a plurality of magnetic bodies are arranged on the teeth, the magnetic bodies are magnetized (post-magnetization) afterward. Therefore, a large magnetization device capable of accommodating the entire stator needs to be operated at a large power.

[0012] The present disclosure has been achieved in order to solve the above problem, and has an object to provide a magnetic gear rotary electric machine having a stator that can be manufactured more easily and a manufacturing method of a stator.

[0013] Means for solving the problem

[0014] In order to solve the above problem, the magnetic gear rotary electric machine of the present disclosure includes a housing, a stator having a stator core fixed to the housing and annular about an axis, coils provided in slots of the stator core, and stator magnets provided at intervals in a circumferential direction on an inner side of the stator core, a first rotor having pole pieces provided at intervals in the circumferential direction on an inner side of the stator about the axis, and a second rotor having a rotor core provided on an inner side of the first rotor and rotor magnets provided at intervals in the circumferential direction on the rotor core, the stator core having a back yoke surrounding the axis and teeth projecting toward an inner side in a radial direction from the back yoke and provided at intervals in the circumferential direction, the stator magnets being mounted in the circumferential direction on end portions on an inner side in the radial direction of the teeth, and portions of the teeth in which the stator magnets are mounted being divided so as to be detachable with respect to other portions of the stator core.

[0015] The manufacturing method of the stator of the present disclosure includes a stator core having a back yoke surrounding an axis and teeth projecting toward an inner side in a radial direction from the back yoke and provided at intervals in a circumferential direction, and stator magnets provided at intervals in the circumferential direction on an inner side of the teeth, the teeth being divided into a first portion in which the stator magnets are mounted and a second portion that is other portion of the stator core in a detachable manner, and the manufacturing method of the stator includes a step of preparing the first portion, a step of preparing the second portion, a step of fixing the stator magnets to the first portion, a step of magnetizing the stator magnets, and a step of combining the first portion and the second portion.

[0016] Effects of the Invention

[0017] According to the present disclosure, it is possible to provide a magnetic gear rotary electric machine having a stator that can be manufactured more easily and a manufacturing method of a stator. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 is a cross-sectional view showing the structure of the magnetic gear rotary electric machine of the embodiment of the present disclosure.

[0019] Figure 2 is a cross-sectional view of II-II line of Figure 1

[0020] ​Figure 3 This is a top view showing the structure of the stator core according to an embodiment of the present disclosure.

[0021] Figure 4 This is a process diagram illustrating each step of the stator manufacturing method according to an embodiment of the present disclosure.

[0022] Figure 5 This is a schematic diagram showing the structure of the magnetizing device used in the stator manufacturing method according to an embodiment of this disclosure.

[0023] Figure 6 This is a top view showing a modified example of the stator core according to an embodiment of the present disclosure. Detailed Implementation

[0024] [First Implementation Method]

[0025] (Structure of a magnetic gear-driven rotary motor)

[0026] The following is for reference Figures 1 to 5 The magnetic gear-driven rotary motor 100 of the first embodiment of this disclosure will be described. For example... Figures 1 to 3 As shown, the magnetic geared rotary motor 100 includes a stator 1, a first rotor 2, a second rotor 3, a housing 4, and a bearing B. The magnetic geared rotary motor 100 is mounted on a rotating shaft 6 extending along the axis Ac. When power is supplied from the outside, the first rotor 2 and the second rotor 3 rotate about the axis Ac, thereby functioning as a motor. On the other hand, when a rotational force (torque) is applied to the rotating shaft 6 from the outside, it functions as a generator through the induced electromotive force accompanying the rotation of the first rotor 2 and the second rotor 3.

[0027] (Structure of the casing and stator)

[0028] The housing 4 is annular in shape with the axis Ac as its center. A space is formed inside the housing 4. The stator 1 is disposed on the inner surface of the housing 4, facing radially inward relative to the axis Ac (inner circumferential surface 5A of the housing).

[0029] like Figure 2As shown, the stator 1 has a stator core 1A, a plurality of coils C, and a plurality of stator magnets 1B. The stator core 1A has a back yoke 71 that is circular ring-shaped with the axis Ac as the center, and a plurality of teeth 7T that project toward the radially inner side from the back yoke 71 and are arranged at intervals in the circumferential direction. The teeth 7T have tooth bodies 72 that extend toward the radially inner side from the back yoke 71, and tooth tip portions 73 that are provided integrally to the end portions of the tooth bodies 72 on the radially inner side. The tooth tip portions 73 project toward both sides in the circumferential direction. The back yoke 71 is divided in the circumferential direction by a plurality (three as one example) of teeth 7T. In other words, the back yoke 71 is configured by joining a plurality of yoke division bodies Py in the circumferential direction. Note that the back yoke 71 can also be configured as a single annular member.

[0030] The coils C are installed to the tooth bodies 72. The coils C are formed by winding a copper wire or the like around the tooth bodies 72. The area surrounded by the back yoke 71, a pair of tooth bodies 72 that are adjacent to each other, and the tooth tip portions 73 becomes a slot S for housing the coils C.

[0031] Also, the tooth tip portions 73 are divided in a detachable manner with respect to the tooth bodies 72. More specifically, as shown in Figure 3 A fitting recess Rc that is recessed toward the radially outer side is formed at the end portion on the inner peripheral side of the tooth body 72. A fitting projection Pc that projects toward the radially outer side is formed at the end portion on the outer peripheral side of the tooth tip portion 73. By fitting the fitting projection Pc and the fitting recess Rc, the tooth body 72 and the tooth tip portion 73 are joined.

[0032] As shown in Figure 2 On the radially inner side of the tooth tip portion 73, a plurality of stator magnets 1B are arranged in an adjacent manner in the circumferential direction. The stator magnets 1B are, for example, permanent magnets such as ferrite magnets or neodymium magnets. The poles (magnetization directions) of the stator magnets 1B that face each other on the inner peripheral side are different from each other with respect to mutually adjacent stator magnets 1B. More specifically, these stator magnets 1B are arranged in a Halbach magnet array. As shown in Figure 5 In the Halbach magnet array, the magnetization direction changes in four directions in a clockwise direction in order from one side to the other side in the circumferential direction. The arrows shown in Figure 5 indicate the magnetization directions of the stator magnets 1B.

[0033] (Structure of first rotor)

[0034] As shown in Figure 1As shown, the first rotor 2 is disposed inside the stator 1. The first rotor 2 has a circular plate portion 5, a first rotor body 2H, and pole pieces 2P. The circular plate portion 5 is circular in shape with the axis Ac as its center and is mounted on the rotating shaft 6. The first rotor body 2H is mounted on the outer periphery of the circular plate portion 5. The first rotor body 2H has a cylindrical portion 21 with the axis Ac as its center and a pair of support portions 22 extending radially outward from the outer periphery of the cylindrical portion 21. The cylindrical portion 21 is supported on the inner periphery of the housing 4 via a bearing B (outer bearing B1) described later. A plurality of pole pieces 2P are provided at the radially outer end edges of the pair of support portions 22. The pole pieces 2P are magnetic materials that generate high-frequency magnetic flux through interaction with the magnetic forces of the stator magnet 1B and the rotor magnet 3B described later. Figure 2 As shown, multiple electrodes 2P are arranged at intervals in the circumferential direction.

[0035] (Structure of the second rotor)

[0036] like Figure 1 As shown, the second rotor 3 is disposed between a pair of support portions 22 within the first rotor body 2H. The second rotor 3 has a rotor core 3A and a rotor magnet 3B. The rotor core 3A is annular about an axis Ac. The inner circumferential surface of the rotor core 3A is supported by the outer circumferential surface of the cylindrical portion 21 in the first rotor body 2H via a bearing B (inner bearing B2) to enable rotation. Figure 2 As shown, multiple rotor magnets 3B are arranged circumferentially on the outer peripheral surface of the rotor core 3A. The rotor magnets 3B are opposite to the aforementioned pole piece 2P from the inner peripheral side.

[0037] (Stator manufacturing method)

[0038] Next, refer to Figure 4 and Figure 5 The manufacturing method of stator 1 will be described. In the following description, the tooth 7T is divided in a detachable manner into a tooth front end 73 (first part P1) on which the stator magnet 1B is mounted, and the remaining part of the stator core 1A including the tooth body 72 (second part P2). The manufacturing method of stator 1 includes: a step S1 of preparing the first part P1; a step S2 of preparing the second part P2; a step S3 of fixing a magnetic body to the first part P1; a step S4 of forming the stator magnet 1B by magnetizing the magnetic body; and a step S5 of combining the first part P1 and the second part P2.

[0039] In the process S1 of preparing the first portion P1, the tooth tip portion 73 is prepared as the first portion P1. In the process S2 of preparing the second portion P2, the other portion of the stator core 1A including the tooth body 72 is prepared as the second portion P2. Next, the tooth tip portion 73 in the state where the plurality of magnetic bodies are fixed (process S3). Next, the tooth tip portion 73 in the state where the magnetic bodies are fixed is subjected to the magnetization processing by the magnetization device 200 as one unit (process S4). Specifically, as shown in FIG. 8, the magnetization device 200 has a plurality of magnetization coils Cm. In the example of FIG. 8, a plurality of (four as one example) groups formed of a pair of magnetization coils Cm having mutually different magnetic flux directions are arranged in the circumferential direction. By energizing these magnetization coils Cm, the magnetic bodies are given the magnetization directions conforming to the above-described Halbach magnet array, and the stator magnet 1B is formed. After that, the tooth tip portion 73 (the first portion P1) in the state where the stator magnet 1B is mounted is combined with the second portion P2 (process S5). Thus, the entire processes of the manufacturing method of the stator 1 are completed. Figure 5 Figure 5

[0040] (EFFECTS)

[0041] Next, the operation of the above-described magnetic gear transmission rotary electric machine 100 is described. In the case where the magnetic gear transmission rotary electric machine 100 is used as a motor, electric power is first supplied from the outside to the coil C. Thus, the coil C is excited. The second rotor 3 is rotated around the axis Ac by the magnetic force of this coil C. Further, the first rotor 2 is rotated by the rotation of the second rotor 3. The rotation speed of the first rotor 2 is reduced on the basis of the reduction ratio based on the number of poles Ph of the first rotor 2 and the number of pole pairs Ns of the second rotor 3. Specifically, the reduction ratio G is G = Ph / Ns.

[0042] On the other hand, in the case where the magnetic gear transmission rotary electric machine 100 is used as a generator, a rotational force (torque) around the axis Ac is applied to the rotation shaft 6. Thus, the first rotor 2 and the second rotor 3 are rotated by the rotation of the rotation shaft 6. Along with the rotation of the first rotor 2 and the second rotor 3, an induced electromotive force is generated in the coil C. By taking out this electric power to the outside, the magnetic gear transmission rotary electric machine 100 can be used as a generator.

[0043] ​​However, in the magnetic gear transmission rotary electric machine 100, the stator 1 sometimes has a large diameter of several m as an example. For example, unlike the above-described embodiment, if the back yoke 71 is divided by every 1 tooth 7T, a slight gap is generated at the division surface, and thus it is difficult to maintain the circularity of the back yoke 71 at the time of assembly. Further, in the magnetic gear transmission rotary electric machine 100, sometimes a plurality of magnetic bodies are arranged on the teeth 7T, and then the magnetic bodies are magnetized after that (post-magnetization). Therefore, a large magnetization device 200 capable of accommodating the entire stator 1 needs to be operated at a large power.

[0044] However, according to the above-described structure, even in the case where the stator magnets 1B are formed by magnetizing the magnetic bodies after that, it is only necessary to magnetize the portion of the teeth 7T in which the stator magnets 1B (magnetic bodies) are mounted as one unit. Thus, the size and power required for the magnetization device 200 can be suppressed to be small. As a result, the magnetic gear transmission rotary electric machine 100 can be manufactured more easily and at a lower cost. Further, since the back yoke 71 does not need to be divided in units of the teeth 7T, the number of division surfaces can be reduced. Thus, the circularity can be easily ensured at the time of assembly. In addition, in the case where the number of division surfaces is large, sometimes noise is generated due to the slight gap generated at the division surface. However, according to the above-described structure, by reducing the number of division surfaces, the generation of such noise can be suppressed.

[0045] According to the above-described structure, the tooth tip portion 73 is detachable with respect to the tooth body 72, and thus at the time of magnetization, it is only necessary to accommodate the tooth tip portion 73 in the magnetization device 200. Thus, the size and power required for the magnetization device 200 can be suppressed to be smaller.

[0046] Further, according to the above-described structure, the stator magnets 1B are arranged in a Halbach magnet array. Thus, the specific directional component of the magnetic field strength generated by the stator magnets 1B can be enhanced. Therefore, the magnetic force performance of the stator magnets 1B can be improved, and the torque of the magnetic gear transmission rotary electric machine 100 can be improved.

[0047] In addition, according to the above-described manufacturing method of the stator 1, at the time of magnetizing the magnetic bodies to form the stator magnets 1B, it is only necessary to magnetize the portion (first portion P1) of the teeth 7T in which the stator magnets 1B (magnetic bodies) are mounted as one unit. Thus, the size and power required for the magnetization device 200 can be suppressed to be small. As a result, the magnetic gear transmission rotary electric machine 100 can be manufactured more easily and at a lower cost. Further, since the back yoke 71 does not need to be divided in units of the teeth 7T, the number of division surfaces can be reduced. Thus, the circularity can be easily ensured at the time of assembly.

[0048] (Other Embodiments)

[0049] The above describes the embodiments of the present disclosure with reference to the drawings, but the specific structure is not limited to the embodiments, and design changes and the like within a range not departing from the gist of the present disclosure are included. For example, in the above-described embodiments, the structure in which the tooth 7T is divided into the tooth tip portion 73 and the tooth main body 72 is described. However, as shown in FIG. 10, a structure in which the tooth 7T is divided at a position halfway in the radial direction of the tooth main body 72 can also be adopted. In other words, in the example of the figure, the tooth 7T is divided into a portion on the back yoke 71 side and a portion including the tooth tip portion 73 in a detachable manner. Figure 6

[0050] According to the above structure, the portion on the tooth tip portion 73 side is detachable with respect to the portion on the back yoke 71 side, and thus when magnetization is performed, it is only necessary to house only the portion on the tooth tip portion 73 side in the magnetization device 200. Thus, the size and the power required for the magnetization device 200 can be suppressed to be smaller.

[0051] [Postscript]

[0052] The magnetic gear transmission rotary electric machine 100 and the manufacturing method of the stator 1 described in each of the embodiments are grasped, for example, as follows.

[0053] (1) The magnetic gear transmission rotary electric machine 100 of the first mode includes: a housing 4; a stator 1 having a stator core 1A fixed to the housing 4 and annular about an axis Ac, a coil C provided in a slot S of the stator core 1A, and a plurality of stator magnets 1B provided at intervals in the circumferential direction on the inner side of the stator core 1A; a first rotor 2 having a plurality of pole pieces 2P provided at intervals in the circumferential direction of the axis Ac on the inner side of the stator 1; and a second rotor 3 having a rotor core 3A provided on the inner side of the first rotor 2 and a plurality of rotor magnets 3B provided at intervals in the circumferential direction on the rotor core 3A, the stator core 1A having: a back yoke 71 that surrounds the axis Ac; and a tooth 7T that protrudes to the inner side in the radial direction from the back yoke 71 and is provided at intervals in the circumferential direction, a plurality of the stator magnets 1B being installed in the circumferential direction at the end portion on the inner side in the radial direction of the tooth 7T, and the portion of the tooth 7T in which the stator magnets 1B are installed being divided to be detachable with respect to the other portion in the stator core 1A.

[0054] ​According to the above structure, even in the case where the magnetic body is magnetized after the fact to form the stator magnet 1B, it is only necessary to magnetize the portion of the tooth 7T in which the stator magnet 1B (magnetic body) is installed as one unit. Thus, the size and the power required for the magnetizing device 200 can be suppressed to be small. As a result, the magnetic gear rotary electric machine 100 can be manufactured more easily and at a lower cost. Also, since the back yoke 71 does not need to be divided in units of the teeth 7T, the number of division surfaces can be reduced. Thus, the circularity can be more easily ensured at the time of assembly. In addition, in the case where the number of division surfaces is large, noise can sometimes occur due to a slight gap that is generated at the division surface. However, according to the above structure, by reducing the division surfaces, the generation of such noise can also be suppressed.

[0055] (2) In the magnetic gear rotary electric machine 100 of the second mode, the tooth 7T has a tooth tip portion 73, which is a portion in which the stator magnet 1B is installed, and a tooth body 72, which connects the tooth tip portion 73 and the back yoke 71, and the tooth tip portion 73 is detachable with respect to the tooth body 72.

[0056] According to the above structure, the tooth tip portion 73 is detachable with respect to the tooth body 72, and thus, at the time of magnetization, it is only necessary to house only the tooth tip portion 73 in the magnetizing device 200. Thus, the size and the power required for the magnetizing device 200 can be suppressed to be smaller.

[0057] (3) In the magnetic gear rotary electric machine 100 of the third mode, the tooth 7T has a tooth tip portion 73, which is a portion in which the stator magnet 1B is installed, and a tooth body 72, which connects the tooth tip portion 73 and the back yoke 71, and the tooth body 72 is divided into a portion on the tooth tip portion 73 side and a portion on the back yoke 71 side in a detachable manner.

[0058] According to the above structure, the portion on the tooth tip portion 73 side is detachable with respect to the portion on the back yoke 71 side, and thus, at the time of magnetization, it is only necessary to house only the portion on the tooth tip portion 73 side in the magnetizing device 200. Thus, the size and the power required for the magnetizing device 200 can be suppressed to be smaller.

[0059] (4) In the magnetic gear rotary electric machine 100 of the fourth mode, the plurality of stator magnets 1B are arranged in a Halbach magnet array.

[0060] According to the above structure, the stator magnets 1B are arranged in a Halbach magnet array. Thus, the specific directional component of the magnetic field strength generated by the stator magnets 1B can be enhanced. Therefore, the magnetic force performance as the stator magnets 1B can be improved, and the torque of the magnetic gear rotary electric machine 100 can be improved.

[0061] (5) A manufacturing method of a stator 1 of a fifth mode, the stator 1 including a stator core 1A having a back yoke 71 surrounding an axis Ac and a plurality of teeth 7T protruding from the back yoke 71 to an inner side in a radial direction and arranged at intervals in a circumferential direction, and a plurality of stator magnets 1B arranged at intervals in the circumferential direction on an inner side of the teeth 7T, the teeth 7T being divided into a first portion P1 in which the stator magnets 1B are installed and a second portion P2 that is another portion in the stator core 1A in a detachable manner, wherein the manufacturing method of the stator 1 includes: a process S1 of preparing the first portion P1; a process S2 of preparing the second portion P2; a process S3 of fixing a magnetic body to the first portion P1; a process S4 of forming the stator magnets 1B by magnetizing the magnetic body; and a process S5 of combining the first portion P1 and the second portion P2.

[0062] According to the above-described method, when the stator magnets 1B are formed by magnetizing the magnetic body, it is only necessary to magnetize the portion (first portion P1) of the teeth 7T in which the stator magnets 1B (magnetic body) are installed as one unit. Thus, the size of the magnetizing device 200 and the required power can be suppressed to be small. As a result, the magnetic gear transmission rotary electric machine 100 can be manufactured more easily and at a lower cost. Furthermore, since the back yoke 71 does not need to be divided in units of the teeth 7T, the number of division surfaces can be reduced. Thus, it is possible to more easily ensure the circularity when assembled.

[0063] Industrial applicability

[0064] According to the present disclosure, it is possible to provide a magnetic gear transmission rotary electric machine having a stator that can be manufactured more easily and a manufacturing method of a stator.

[0065] Explanation of reference numerals

[0066] 100 magnetic gear transmission rotary electric machine

[0067] 1 stator

[0068] 1A stator core

[0069] 1B stator magnet

[0070] 2 first rotor

[0071] 21 barrel portion

[0072] 22 support portion

[0073] 2H first rotor main body

[0074] 2P pole piece

[0075] 3 Second rotor

[0076] 3A Rotor core

[0077] 3B Rotor magnet

[0078] 4 Housing

[0079] 5 Circular plate portion

[0080] 5A Inner circumferential surface of housing

[0081] 6 Rotation shaft

[0082] 71 Back yoke

[0083] 72 Tooth body

[0084] 73 Tooth tip portion

[0085] 200 Magnetizing device

[0086] Ac Axis

[0087] B Bearing

[0088] B1 Outer bearing

[0089] B2 Inner bearing

[0090] C Coil

[0091] Cm Magnetizing coil

[0092] P1 First portion

[0093] P2 Second portion

[0094] Pc Engaging convex portion

[0095] Py Yoke division

[0096] Rc Engaging concave portion

[0097] S Slot

Claims

1. A magnetic-geared rotary electric machine, wherein the magnetic-geared rotary electric machine comprises: a housing; a stator having a stator core fixed to the housing and annular about an axis, coils provided in slots of the stator core, and stator magnets provided at the inner side of the stator core in a plurality of positions in the circumferential direction; a first rotor having pole pieces provided at the inner side of the stator in a plurality of positions in the circumferential direction of the axis; and a second rotor having a rotor core provided at the inner side of the first rotor and rotor magnets provided in a plurality of positions in the circumferential direction of the rotor core, the stator core has: a back yoke surrounding the axis; and teeth projecting from the back yoke toward the radially inner side and provided in a plurality of positions in the circumferential direction, the stator magnets are mounted in a plurality of positions in the circumferential direction at the radially inner side of the teeth, the portion of the teeth in which the stator magnets are mounted is detachable with respect to other portions of the stator core, the teeth have: a tooth tip portion which is the portion in which the stator magnets are mounted; and a tooth body connecting the tooth tip portion and the back yoke, the tooth tip portion is detachable with respect to the tooth body.

2. The magnetic-geared rotary electric machine according to claim 1, wherein the plurality of stator magnets are arranged in a Halbach magnet array.

3. A method of manufacturing a stator having a stator core having a back yoke surrounding an axis and teeth projecting from the back yoke toward the radially inner side and provided in a plurality of positions in the circumferential direction, and stator magnets provided in a plurality of positions in the circumferential direction at the inner side of the teeth, the teeth have: a tooth tip portion which is the portion in which the stator magnets are mounted; and a tooth body connecting the tooth tip portion and the back yoke, the teeth have a first portion which is the tooth tip portion in which the stator magnets are mounted, the first portion being detachable with respect to a second portion which is other portions of the stator core including the tooth body, the method of manufacturing the stator comprises: a step of preparing the first portion; a step of preparing the second portion; a step of fixing a magnetic body to the first portion; a step of forming the stator magnets by magnetizing the magnetic body; and a step of combining the first portion and the second portion. ​ ​

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