Stator, magnetic gear electric machine, and method for assembling stator

Abstract

To provide a stator, a magnetic gear electric machine, and a method for assembling a stator, capable of preventing at least one of a plurality of magnets from falling out with a simple configuration.SOLUTION: A stator core includes: a core inner peripheral surface that is an inner peripheral surface on which a plurality of magnets is arranged; a first protrusion that protrudes from the core inner peripheral surface toward the inside in the radial direction and that has a first support surface supporting a first inclined surface; and a second protrusion that protrudes from the core inner peripheral surface toward the inside in the radial direction and that has a second support surface supporting a second inclined surface. Both the first support surface and the second support surface are inclined with respect to the radial direction and are inclined toward a center side of a first radial magnet as the surfaces extend toward the inside in the radial direction.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present disclosure relates to a stator, a magnetic gear electric machine, and a method for assembling a stator. [Background technology]

[0002] The stator disclosed in Patent Document 1 is incorporated into a magnetic gear device. The stator includes a stator core and a plurality of magnets arranged in the circumferential direction on the radially inner side of the stator core. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] US Patent Application Publication No. 2019 / 0157962 Summary of the Invention [Problem to be solved by the invention]

[0004] The inventors of the present application have devised the application of a Halbach array, which concentrates magnetic flux radially inward from the stator, to the magnet arrangement of the stator. However, since the magnetization directions of adjacent magnets in the circumferential direction are different, there is a concern that the magnets may come off from the multiple teeth of the stator core. According to the inventors' findings, magnets magnetized radially outward are urged radially inward by magnetic forces caused by other magnets, and there is a particular concern that the magnets may fall off. Furthermore, it is preferable to suppress such magnets from falling off with a simple configuration.

[0005] An object of the present disclosure is to provide a stator, a magnetic gear electric machine, and a method for assembling a stator that can suppress the falling off of at least one of a plurality of magnets with a simple configuration. [Means for solving the problem]

[0006] A stator according to at least one embodiment of the present disclosure includes: A stator core; A plurality of magnets including a magnet group arranged continuously in a circumferential direction on the inner circumferential side of the stator core, the magnet group being a plurality of magnets arranged in a Halbach array; A stator comprising: The magnet group includes a first radial magnet magnetized radially outward; The first radial magnet is The outer periphery and a first inclined surface that is connected to one end of the outer circumferential surface in the circumferential direction and inclined toward the center of the first radial magnet in the circumferential direction as it moves toward the inside in the radial direction; a second inclined surface that is connected to the other end of the outer circumferential surface in the circumferential direction and inclined toward the center of the first radial magnet as it moves toward the inside in the radial direction; having The stator core is a core inner peripheral surface on which the plurality of magnets are arranged; a first protrusion protruding inward in the radial direction from the core inner circumferential surface and having a first support surface that supports the first inclined surface; a second protrusion protruding inward in the radial direction from the core inner circumferential surface and having a second support surface that supports the second inclined surface; Including, Both the first support surface and the second support surface are inclined with respect to the radial direction, and are inclined toward the center side of the first radial magnet as they move inward in the radial direction.

[0007] A magnetic gear electric machine according to at least one embodiment of the present disclosure comprises: The stator described above; a pole piece rotor including a plurality of pole pieces arranged in the circumferential direction on the radially inner side of the stator; a magnet rotor including an inner magnet arranged radially inward of the plurality of magnetic pole pieces; Equipped with.

[0008] A method for assembling a stator according to an embodiment of the present disclosure includes: A method for assembling the stator, comprising the steps of: The method includes the step of sliding the first radial magnet in an axial direction to engage the first inclined surface with the first protrusion and to engage the second inclined surface with the second protrusion. Effect of the Invention

[0009] According to the present disclosure, it is possible to provide a stator, a magnetic gear electric machine, and a method for assembling a stator that can suppress the falling off of at least one of a plurality of magnets with a simple configuration. [Brief description of the drawings]

[0010] [Figure 1] FIG. 1 is a schematic diagram of a magnetic gear electric machine according to an embodiment. [Diagram 2] FIG. 2 is a schematic diagram of a stator according to an embodiment. [Diagram 3] FIG. 3 is a partially enlarged view of FIG. [Figure 4] FIG. 4 is a partially enlarged view of FIG. [Diagram 5] 1 is a schematic diagram of a stator core according to a first embodiment. [Figure 6] FIG. 11 is a schematic diagram of a stator core according to a second embodiment. [Figure 7] FIG. 11 is a schematic diagram showing an assembly process of the first radial magnet according to the second embodiment. [Figure 8] 8 is a schematic diagram showing the assembly process of the first radial magnets following FIG. 7. FIG. [Figure 9] 4 is a schematic diagram showing a detailed example of a first divided magnet and a second divided magnet. FIG. [Figure 10] FIG. 11 is a schematic diagram of a stator core according to a third embodiment. [Figure 11] FIG. 11 is a schematic diagram of a first radial magnet according to a third embodiment. [Figure 12] FIG. 11 is a schematic diagram showing an assembly process of the first radial magnet according to the third embodiment. [Figure 13A] FIG. 2 is a schematic diagram of a plate according to a first example. [Figure 13B] FIG. 11 is a schematic diagram of a plate according to a second example. [Figure 13C]FIG. 11 is a schematic diagram of a plate according to a third example. [Figure 14] 4 is a flowchart of a method for assembling a stator according to an embodiment. [Figure 15] 11A-11C are schematic diagrams showing the process of a radial magnet placement step according to one embodiment. [Figure 16] FIG. 13 is a schematic diagram of a stator according to another embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Hereinafter, some embodiments of the present disclosure will be described with reference to the accompanying drawings. However, the dimensions, materials, shapes, relative arrangements, etc. of components described as the embodiments or shown in the drawings are merely illustrative examples and are not intended to limit the scope of the present disclosure. For example, expressions expressing relative or absolute configuration, such as "in a certain direction," "along a certain direction," "parallel," "orthogonal," "center," "concentric," or "coaxial," not only strictly express such a configuration, but also express a state in which there is a relative displacement with a tolerance or an angle or distance to the extent that the same function is obtained. For example, expressions indicating that things are in an equal state, such as "identical," "equal," and "homogeneous," not only indicate a state of strict equality, but also indicate a state in which there is a tolerance or a difference to the extent that the same function is obtained. For example, expressions describing shapes such as a rectangular shape or a cylindrical shape do not only refer to rectangular shapes, cylindrical shapes, etc. in the strict geometric sense, but also refer to shapes that include uneven portions, chamfered portions, etc., to the extent that the same effect is obtained. On the other hand, the expressions "comprise", "include", or "have" a certain element are not exclusive expressions excluding the presence of other elements. In addition, the same components are denoted by the same reference numerals and the description thereof may be omitted.

[0012] <Overall Configuration of Magnetic Gear Electric Machine 10> FIG. 1 is a schematic diagram of a magnetic gear electric machine 10 according to an embodiment of the present disclosure. The magnetic gear electric machine 10 includes a rotating shaft 18 connected to an external device 9. In the following description, the term "axial direction" refers to the axial direction of the axis S of the rotating shaft 18, the term "circumferential direction" refers to the circumferential direction based on the axis S, and the term "radial direction" refers to the radial direction based on the axis S. The term "radial inner side" refers to the direction toward the axis S, and the term "radial outer side" refers to the direction away from the axis S. The axis S is also the axis of a stator (stator 20) for the magnetic gear electric machine 10, which will be described later.

[0013] The magnetic gear electric machine 10 comprises a housing 17 which rotatably supports a rotating shaft 18 and a stator 20 fixed to the housing 17 .

[0014] The stator 20 includes a stator core 24, which includes a yoke 29 extending in the circumferential direction and a plurality of teeth 25 protruding radially inward from the yoke 29. The plurality of teeth 25 are arranged at intervals in the circumferential direction. The stator 20 further includes a plurality of magnets 5 arranged in the circumferential direction on the inner peripheral side of the stator core 24, and a stator coil 27 wound around the plurality of teeth 25. The stator coil 27 is electrically connected to the power system 16. In this example, a surface permanent magnet (SPM) type configuration is adopted in which the plurality of magnets 5 are arranged on the inner peripheral surface of the stator core 24. The SPM type configuration of the stator 20 may be the configuration shown in FIG. 1 in which the magnets 5 are directly attached to the teeth inner peripheral surface 259, which is the inner peripheral surface of the teeth 25.

[0015] The magnetic gear electric machine 10 shown in FIG. 1 further includes a pole piece rotor 30. The pole piece rotor 30 includes an annular body 35 extending along the axis S radially inward of the stator 20, a connecting member 31 connecting one end of the annular body 35 to the rotating shaft 18, and a connecting member 32 connecting the other end of the annular body 35 to the rotating shaft 18. The annular body 35 includes a plurality of pole pieces 36 and a plurality of non-magnetic bodies (not shown) alternately arranged along the circumferential direction. The annular body 35 faces the stator 20 in the radial direction with the outer air gap G1 therebetween. For example, if the inner circumferential surface 15 of each of the plurality of magnets 5 is exposed to the outer air gap G1, the annular body 35 faces the plurality of magnets 5. Alternatively, if another member such as a plate 70 (see FIGS. 13A to 13C) is attached to the inner circumferential surface 15, the annular body 35 faces the other member.

[0016] The connecting members 31, 32 extend along the radial direction. The connecting members 31, 32 illustrated in FIG. 1 are fixed to the rotating shaft 18, and the pole piece rotor 30 is configured to rotate integrally with the rotating shaft 18. The pole pieces 36 may be multiple electromagnetic steel sheets stacked in the axial direction, or at least one powder magnetic core extending in the axial direction, or a combination of these. If multiple electromagnetic steel sheets are stacked, the pole pieces 36 can suppress eddy current loss during generation.

[0017] The magnetic gear electric machine 10 further includes a magnet rotor 40 connected to the rotating shaft 18 between the connecting members 31, 32. The magnet rotor 40 includes a plurality of inner magnets 41 arranged in the circumferential direction radially inside the annular body 35, and a rotor core 42 supporting the inner magnets 41. The rotor core 42 is connected to the rotating shaft 18 via a bearing, and the magnet rotor 40 is configured to rotate relatively to the rotating shaft 18. The magnet rotor 40 faces the annular body 35 in the radial direction with an inner air gap G2 therebetween. In the example of FIG. 1, an SPM type configuration in which the plurality of inner magnets 41 are arranged on the outer circumferential surface of the rotor core 42 is adopted, but an Interior Permanent Magnet (IPM) type configuration in which the plurality of inner magnets 41 are arranged inside the rotor core 42 may also be adopted.

[0018] The magnetic gear electric machine 10 according to one embodiment is a magnetic gear motor that receives power from a power system 16 to drive an external device 9, and its operating principle is as follows: A rotating magnetic field is generated when a current is applied to the stator coil 27, causing the magnet rotor 40 to rotate. The relative positional relationship of the annular body 35 to the multiple inner magnets 41 and the multiple magnets 5 changes in the circumferential direction, and the magnetic flux between the magnet rotor 40 and the stator 20 is modulated by the multiple pole pieces 36, causing the pole piece rotor 30 to rotate. Torque is transmitted from the rotating shaft 18 that rotates together with the pole piece rotor 30 to the external device 9, driving the external device 9.

[0019] The magnetic gear electric machine 10 according to another embodiment is a magnetic gear generator that receives power from an external device 9 and supplies electric power to a power grid 16, and its operating principle is as follows. When the external device 9 drives the rotating shaft 18, the pole piece rotor 30 rotates together with the rotating shaft 18. The relative positional relationship of the annular body 35 to the multiple inner magnets 41 and the multiple magnets 5 changes in the circumferential direction, causing the magnet rotor 40 to rotate. Electromagnetic induction occurs as the pole piece rotor 30 and the magnet rotor 40 rotate, generating a current in the stator coil 27, and power is supplied to the power grid 16.

[0020] If the number of magnetic poles in the pole piece 36 is NL, the number of magnetic pole pairs in the inner magnet 41 is NH, and the number of magnetic pole pairs in the magnet 5 is NS, then NL=NH+NS holds. When this relation holds, the ratio of the rotation speed of the magnet rotor 40 to the pole piece rotor 30 is expressed as NL / NH. In this example, NL / NH is greater than 1, and the magnet rotor 40 functions as a high-speed rotor, and the pole piece rotor 30 functions as a low-speed rotor. The number of magnetic poles NL in the pole piece 36 is less than the number of pole pairs NS in the magnet 5.

[0021] The magnetic gear electric machine 10 of the present disclosure is not limited to the above embodiment. The external device 9 may be connected to a power transmission shaft (not shown) arranged coaxially with the rotating shaft 18. The power transmission shaft and the rotating shaft 18 are not connected to each other. In this case, the connecting member 31 is connected to the rotating shaft 18 via a bearing, and the connecting member 32 is fixed to the power transmission shaft. Furthermore, the rotor core 42 of the magnet rotor 40 is fixed to the rotating shaft 18. Therefore, the magnet rotor 40 rotates integrally with the rotating shaft 18, and the pole piece rotor 30 rotates relative to the rotating shaft 18.

[0022] <Basic configuration of stator 20> 2 is a schematic diagram of a stator 20 according to an embodiment of the present disclosure. Each of the multiple teeth 25 constituting the stator core 24 includes a protruding portion 251 protruding radially inward from a yoke 29, and a tip portion 252 connected to the tip of the protruding portion 251. The yoke 29, the protruding portion 251, and the tip portion 252 are integrally formed of the same soft magnetic material. The protruding portion 251 is shorter than the tip portion 252 in the circumferential direction. The stator coil 27 is provided so as to be wound around the protruding portion 251.

[0023] A slot opening 201 is formed as a space between two circumferentially adjacent tip portions 252, and a holding member 209, which may be made of, for example, a resin member, is disposed in the slot opening 201. The holding member 209 is held by the circumferential ends of each of the two tip portions 252.

[0024] The multiple magnets 5 are arranged on the inner circumferential side of the stator core 24. In the following description, the inner circumferential surface of the stator core 24 on which the multiple magnets 5 are arranged may be referred to as the "core inner circumferential surface 26." In the example of Fig. 2, the teeth inner circumferential surface 259 and the inner circumferential surface of the retaining member 209 correspond to the core inner circumferential surface 26A (26) according to one embodiment. However, the present disclosure is not limited thereto. When another member is interposed between the tip portion 252 and the holding member 209 and the plurality of magnets 5, the inner circumferential surface of the other member corresponds to the core inner circumferential surface 26B (26) according to another embodiment (see FIG. 17). The core inner circumferential surface 26B will be described in detail later.

[0025] The magnet 5 will be described further with reference to FIG. 2. The magnets 5 include a magnet group (four magnets 5 arranged in succession in the circumferential direction as an example) arranged in a circumferential direction, and the magnet group is arranged in a Halbach array. This Halbach array strengthens the magnetic flux caused by the magnets 5 on the radial inner side of the magnets 5 compared to the radial outer side. The stator 20 of this embodiment employs a configuration in which a plurality of magnet groups each consisting of four magnets 5 are arranged. That is, the total number of magnets 5 constituting the stator 20 is a multiple of four. In FIG. 2, the four magnets 5 included in one magnet group are surrounded by a two-dot chain line J. Each magnet 5 extending in the axial direction is composed of a plurality of permanent magnets 12 stacked in the axial direction (see FIG. 16). In this specification, each magnet 5 extending in the axial direction (see FIG. 2) is counted as one for convenience of explanation. The plurality of permanent magnets 12 do not necessarily have the same shape. Details will be described later.

[0026] Hereinafter, the group of magnets arranged in the Halbach array may be referred to as "four magnets 5."

[0027] The four magnets 5 arranged in the Halbach array include a first radial magnet 1 magnetized radially outward, a first circumferential magnet 3 magnetized on one side of the circumferential direction, a second circumferential magnet 4 magnetized on the other side of the circumferential direction, and a second radial magnet 2 magnetized radially inward. The first circumferential magnet 3 is located on one side of the circumferential direction from the first radial magnet 1, the second circumferential magnet 4 is located on the other side of the circumferential direction from the first radial magnet 1, and the second radial magnet 2 is located on the other side of the circumferential direction from the second circumferential magnet 4. The magnetization directions of these four magnets 5 are indicated by thick arrows on each magnet 5, and the end of each magnet 5 on the side in which the arrow points is the N pole. In this example, the magnetization direction components of the first radial magnet 1 and the second radial magnet 2 include only radial components and do not include circumferential components. In addition, the magnetization direction components of the first circumferential magnet 3 and the second circumferential magnet 4 include only circumferential components and do not include radial components. However, the present disclosure is not limited to this, and each magnetization direction component of the first circumferential magnet 3 and the second circumferential magnet 4 may include a radial component in addition to a circumferential component (details will be described later).

[0028] FIG. 3 is a partially enlarged view of FIG. 2. Arrows A1 to A4 indicate the magnetic force that each magnet 5 receives due to the magnetic flux of the other magnets 5. More specifically, arrow A1 indicates the magnitude and direction of the magnetic force received by the first radial magnet 1. Similarly, arrow A2 indicates the direction and magnitude of the magnetic force received by the second radial magnet 2, arrow A3 indicates the direction and magnitude of the magnetic force received by the first circumferential magnet 3, and arrow A4 indicates the direction and magnitude of the magnetic force received by the second circumferential magnet 4. The length of the arrows A1 to A4 indicates the magnitude of the magnetic force, and the longer the arrow, the greater the magnetic force. The direction and magnitude of these magnetic forces can be determined by simulation.

[0029] As can be seen from FIG. 3, the first radial magnet 1 is subjected to the largest magnetic force directed radially inward, and the risk of the first radial magnet 1 falling off is higher than the risk of the remaining three magnets 5 falling off. In addition, the second radial magnet 2 is also subjected to a magnetic force directed radially inward, and the risk of the second radial magnet 2 falling off is higher than the risk of the first circumferential magnet 3 and the second circumferential magnet 4 falling off. Therefore, in this example, a protrusion 50 for supporting the first radial magnet 1 and the second radial magnet 2 is provided on the core inner surface 26A (26). Note that, since a magnetic force directed radially outward acts on the first circumferential magnet 3 and the second circumferential magnet 4, a configuration for supporting these two magnets 5 is not essential.

[0030] The protrusions 50 include a first protrusion 51 and a second protrusion 52 that support the first radial magnet 1, and a third protrusion 53 and a fourth protrusion 54 that support the second radial magnet 2. The first protrusion 51 and the second protrusion 52 each support both end faces in the circumferential direction of the first radial magnet 1, and the third protrusion 53 and the fourth protrusion 54 each support both end faces in the circumferential direction of the second radial magnet 2. In this example, the first protrusion 51, the second protrusion 52, the third protrusion 53, and the fourth protrusion 54 are arranged in order from one side to the other side in the circumferential direction.

[0031] The first radial magnet 1 and the second radial magnet 2 have the same shape. The first protrusion 51 and the third protrusion 53 have the same shape, and the second protrusion 52 and the fourth protrusion 54 have the same shape. To avoid repetition, the following mainly describes the structure in which the first radial magnet 1 is supported by the first protrusion 51 and the second protrusion 52. Any of the components related to the support structure of the first radial magnet 1 described below can also be applied to the support structure of the second radial magnet 2.

[0032] <Outline of the support structure for the first radial magnet 1> Prior to describing the support structure of the first radial magnet 1, an outline of the shape of the first radial magnet 1 will be described with reference to FIG. 4. FIG. 4 is a partially enlarged view of FIG. 3. The first radial magnet 1 has an outer peripheral surface 65 that abuts against the inner peripheral surface 259 of the teeth, a first inclined surface 61 that connects to one end 65a in the circumferential direction of the outer peripheral surface 65, and a second inclined surface 62 that connects to the other end 65b in the circumferential direction of the outer peripheral surface 65. The first inclined surface 61 and the second inclined surface 62 are inclined toward the center (virtual line K1) of the first radial magnet 1 in the circumferential direction as they move toward the inside in the radial direction. Both the first inclined surface 61 and the second inclined surface 62 in this example are inclined with respect to the radial direction. The first inclined surface 61 may be directly connected to the one end 65a, or may be indirectly connected via another surface such as a curved surface. Similarly, the second inclined surface 62 may be directly connected to the other end 65b, or may be indirectly connected.

[0033] In this example, the radial length (dimension M1) of the first inclined surface 61 is 50% or less, more specifically 25% or less, of the radial length of the first radial magnet 1. Similarly, the radial length of the second inclined surface 62 is 50% or less, more specifically 25% or less, of the radial length of the first radial magnet 1. Although not a required component of the present disclosure, the first radial magnet 1 has a circumferentially symmetrical shape, and the first inclined surface 61 and the second inclined surface 62 have the same radial length.

[0034] The first radial magnet 1 of this example further has an inner peripheral surface 66 (15) facing inward in the radial direction, a first connecting surface 63 connecting to the first inclined surface 61 and the inner peripheral surface 66, and a second connecting surface 64 connecting to the second inclined surface 62 and the inner peripheral surface 66. The first connecting surface 63 is directly connected to the inner end of the first inclined surface 61 in the radial direction, and the second connecting surface 64 is directly connected to the inner end of the second inclined surface 62 in the radial direction. Although not essential components of the present disclosure, the first connecting surface 63 and the second connecting surface 64 are flat surfaces extending parallel to the radial direction.

[0035] The first protrusion 51 and the second protrusion 52 will be described. Both the first protrusion 51 and the second protrusion 52 protrude radially inward from the core inner circumferential surface 26. As a more specific example, the first protrusion 51 and the second protrusion 52 protrude radially inward from the tooth inner circumferential surface 259. In this example, the first protrusion 51, the second protrusion 52, and the tooth 25 are integrally formed from the same material. The radial length (dimension N1) of the first protrusion 51 is 25% or less, more specifically 10% or less, of the radial length of the first radial magnet 1. In addition, the radial length of the first protrusion 51 may be shorter than the radial length of the first inclined surface 61. Similarly, the radial length of the second protrusion 52 is 25% or less, more specifically 10% or less, of the radial length of the first radial magnet 1. The radial length of the second protrusion 52 may be shorter than the radial length of the second inclined surface 62. The first protrusion 51 and the second protrusion 52 of this example are symmetrical to each other in the circumferential direction.

[0036] In this example, a plurality of first protrusions 51 and a plurality of second protrusions 52 are provided over the entire circumferential length of the stator core 24. At least one of the plurality of first protrusions 51 and the plurality of second protrusions 52 may protrude radially inward from the above-mentioned holding member 209 (see FIG. 2). In this case, the protrusion 50 and the holding member 209 are integrally formed of the same material.

[0037] The first protrusion 51 and the second protrusion 52 will be described with reference to FIG. 4. The first protrusion 51 has a first support surface 55 that supports the first inclined surface 61, and the second protrusion 52 has a second support surface 56 that supports the second inclined surface 62. Both the first support surface 55 and the second support surface 56 are inclined with respect to the radial direction and are inclined toward the center side in the circumferential direction of the first radial magnet 1 as they move toward the inside in the radial direction. The first support surface 55 may directly abut the first inclined surface 61, or may indirectly abut the first inclined surface 61 via another member such as an adhesive. Similarly, the second support surface 56 may directly abut the second inclined surface 62, or may indirectly abut the second inclined surface 62. In the illustrated example, the first inclined surface 61 and the second inclined surface 62 are parallel to the first support surface 55 and the second support surface 56, respectively, but the present disclosure is not limited thereto. For example, when another member is interposed between the first inclined surface 61 and the first support surface 55, the first inclined surface 61 may be non-parallel to the first support surface 55. Similarly, the second inclined surface 62 may be non-parallel to the second support surface 56.

[0038] According to the above configuration, since the first support surface 55 and the second support surface 56 are inclined with respect to the radial direction, the radially outward forces F1 and F2 acting on the first radial magnet 1 from the first support surface 55 and the second support surface 56 can be increased, and the first radial magnet 1 can be prevented from falling off. In addition, since the force acting on the first radial magnet 1 can be increased without increasing the radial length of each of the first support surface 55 and the second support surface 56, the radial length of each of the first protrusions 51 and the second protrusions 52 can be shortened, and the configuration of the stator core 24 can be simplified. As described above, a stator 20 that can prevent at least one of the multiple magnets 5 from falling off with a simple configuration is realized. The stator core 24 does not have to include the third protrusion 53 and the fourth protrusion 54. As described above, the risk of the second radial magnet 2 falling off is smaller than the risk of the first radial magnet 1 falling off, so a configuration may be adopted in which the second radial magnet 2 is attached to the tooth inner circumferential surface 259 by, for example, an adhesive. Even in such an embodiment, the above-mentioned advantages can be obtained.

[0039] Furthermore, according to a configuration in which the core inner circumferential surface 26A (26) includes the tooth inner circumferential surface 259, the first protrusion 51 and the second protrusion 52 can be integrated with the multiple teeth 25, thereby further simplifying the configuration of the stator 20.

[0040] Further details of the first projection 51 and the second projection 52 will be described below in the order of a first embodiment, a second embodiment, and a third embodiment. However, the present disclosure is not limited to these three embodiments. In the following description, one side in the axial direction may be simply referred to as the "first side," and the other side in the axial direction may be simply referred to as the "second side."

[0041] <Details of the First Protrusion 51 and the Second Protrusion 52 (First Embodiment)> FIG. 5 is a schematic diagram of a stator 20A (20) according to the first embodiment. The stator 20A includes a stator core 24A (24). The first protrusion 51A (51) and the second protrusion 52A (52) of the stator core 24A are both provided on a teeth inner peripheral surface 259, which is an example of a core inner peripheral surface 26. In the example shown in the figure, at least one of the first protrusion 51A and the second protrusion 52A extends continuously in the axial direction over the entire axial length of the teeth inner peripheral surface 259. In the example shown in the figure, both the first protrusion 51A and the second protrusion 52A extend continuously in the axial direction and support a first radial magnet 1A (1).

[0042] The first radial magnet 1A according to the first embodiment shown in Fig. 5 is composed of a single member extending in the axial direction, but the present disclosure is not limited to this. For example, the first radial magnet 1 may be composed of a plurality of permanent magnets 12 (see Fig. 16), or as a more detailed example, a plurality of first divided magnets 111 and second divided magnets 222 (see Fig. 6).

[0043] The following illustrates a method of assembling the first radial magnet 1A. The first radial magnet 1A is disposed on the second axial side relative to the stator core 24. The first radial magnet 1A is slid axially toward the first side (arrow B1 in FIG. 5) so that the first inclined surface 61 engages with the first support surface 55 and the second inclined surface 62 engages with the second support surface 56. This allows the first radial magnet 1A to be assembled to the first protrusions 51A and the second protrusions 52A. By repeatedly performing this type of assembly, a plurality of first radial magnets 1A are assembled to the stator core 24A in the circumferential direction.

[0044] In another example of the method for assembling the first radial magnet 1A, the first support surface 55 of the first protrusion 51A and the second support surface 56 of the second protrusion 52A may both be parallel to the radial direction before the first radial magnet 1A is arranged. As a more specific example, the protruding directions of the first protrusion 51A and the second protrusion 52A may both be parallel to the radial direction before the first radial magnet 1A is arranged. In this case, the first radial magnet 1A may be arranged between the first protrusion 51A and the second protrusion 52A, and then the first protrusion 51A and the second protrusion 52A may be deformed toward the first radial magnet 1A. With this deformation, the first support surface 55 engages with the first inclined surface 61, and the second support surface 56 engages with the second inclined surface 62.

[0045] According to the above configuration, the axial range in which the first radial magnet 1A is supported by at least one of the first protrusions 51A and the second protrusions 52A can be expanded, so that the first radial magnet 1A can be further prevented from falling off.

[0046] <Details of the First Protrusion 51 and the Second Protrusion 52 (Second Embodiment)> FIG. 6 is a schematic diagram of a stator 20B (20) according to the second embodiment. The stator 20B includes a stator core 24B (24). The stator core 24B includes a plurality of first projections 51B (51) arranged at intervals in the axial direction and a plurality of second projections 52B (52) arranged at intervals in the axial direction. The axial length of each of the first projections 51B and the axial length of each of the second projections 52B are the same as each other. The axial range in which the plurality of first projections 51B are arranged is the same as the axial range in which the plurality of second projections 52B are arranged. For example, such a stator core 24 may have a configuration in which a plurality of types of laminated steel plates are laminated. The plurality of types of laminated steel plates include a first laminated steel plate for forming the first projections 51B and the second projections 52B, and a second laminated steel plate in which the first projections 51B and the second projections 52B are not formed.

[0047] The first radial magnet 1B(1) supported by the first protrusion 51B and the second protrusion 52B includes a first divided magnet 111B(111) and a second divided magnet 222B(222) arranged so as to be stacked in the axial direction. In this example, the first divided magnets 111B and the second divided magnets 222B are arranged so as to be alternately stacked in the axial direction. The first divided magnet 111B engages with the first protrusion 51B and the second protrusion 52B. On the other hand, the second divided magnet 222C is arranged so as to be shifted in the axial direction from the first protrusion 51B and the second protrusion 52B. Both the first divided magnet 111B and the second divided magnet 222B are examples of stacked permanent magnets 12 (see FIG. 16) constituting the magnet 5.

[0048] 6, the first divided magnet 111B has a first inclined surface 61, a second inclined surface 62, a first connecting surface 63, and a second connecting surface 64. These surfaces have been described above. The number of first divided magnets 111 is the same as the number of first protrusions 51B (i.e., the number of second protrusions 52B), and the axial length of each first divided magnet 111 is the same as the axial length of each first protrusion 51B and the axial length of each second protrusion 52B.

[0049] The second divided magnet 222B does not have the first inclined surface 61, the second inclined surface 62, the first connecting surface 63, and the second connecting surface 64. One end surface in the circumferential direction of the second divided magnet 222B, which may have a substantially rectangular parallelepiped shape as an example, is flush with the first connecting surface 63 of the first divided magnet 111B. The other end surface in the circumferential direction of the second divided magnet 222B is flush with the second connecting surface 64 of the first divided magnet 111B. Therefore, the second divided magnet 222B is disposed between the tip 511 of the first protrusion 51B and the tip 522 of the second protrusion 52B in the circumferential direction. In other words, the second divided magnet 222 is disposed between the tips 511 and 522 when viewed in the axial direction.

[0050] Each first divided magnet 111B has a first magnet end face 115 which is an end face on the first side, and each second divided magnet 222B has a second magnet end face 125 which is an end face on the second side. The first magnet end face 115 and the second magnet end face 125 are in contact with each other via an adhesive. Therefore, even if only the first divided magnet 111B of the first divided magnet 111B or the second divided magnet 222B is supported by the first protrusion 51B and the second protrusion 52B, the first radial magnet 1B is prevented from falling off.

[0051] 6 to 8, an assembly method for the first radial magnet 1B according to the second embodiment is illustrated. FIGS. 7 and 8 are schematic diagrams showing the assembly process for the first radial magnet 1B. As shown in FIG. 7, the first radial magnet 1B is disposed radially inward of the first protrusions 51B and the second protrusions 52B. At this time, the first divided magnet 111B is shifted in the axial direction from the first protrusions 51B and the second protrusions 52B.

[0052] Next, the first radial magnet 1B is moved radially outward (arrow D1 in FIG. 7) and brought into contact with the tooth inner circumferential surface 259 (see FIG. 8). At this time, the first split magnet 111B is offset in the axial direction from the first protrusion 51B and the second protrusion 52B, so interference between the first split magnet 111B and the first protrusion 51B and the second protrusion 52B can be avoided. In addition, the second split magnet 222 is positioned between the protrusions 511, 522 in the circumferential direction, so interference between the second split magnet 222B and the first protrusion 51B and the second protrusion 52B can also be avoided.

[0053] Thereafter, the first radial magnet 1B is slid in the axial direction (arrow D2 in FIG. 8) to engage the first divided magnet 111B with the first protrusions 51B and the second protrusions 52B (see FIG. 6). As a result, the first radial magnet 1B is assembled to the first protrusions 51B and the second protrusions 52B. By repeatedly performing such assembly, a plurality of first radial magnets 1B are assembled to the stator core 24B in the circumferential direction.

[0054] According to the above configuration, the first radial magnet 1B is divided into the first divided magnet 111B and the second divided magnet 222B as the multiple permanent magnets 12, so that the eddy current loss generated in the first radial magnet 1B can be reduced. Also, the axial length of each of the first protrusions 51B and the second protrusions 52B can be made shorter than the axial length of the teeth 25, so that the configuration of the stator core 24B can be further simplified. Furthermore, in the assembly process of the first radial magnet 1B, the first radial magnet 1B can be moved from the inner side to the outer side in the radial direction (arrow D1 in FIG. 7) in a state where the first divided magnet 111B is axially shifted from the first protrusions 51B and the second protrusions 52B, so that the first radial magnet 1B can be brought into contact with the teeth inner circumferential surface 259, which is an example of the core inner circumferential surface 26A. Thereafter, the first radial magnet 1B is slid in the axial direction (arrow D2 in FIG. 8) to engage the first divided magnet 111B with the first protrusion 51B and the second protrusion 52B, thereby attaching the first radial magnet 1B to the stator core 24B. Since the amount of sliding of the first radial magnet 1B in the axial direction can be reduced, it is also possible to facilitate the assembly of the stator 20B. The number of first protrusions 51B and the number of second protrusions 52B may each be 1. Even in this case, the above-mentioned advantages can be obtained.

[0055] Furthermore, according to a configuration in which multiple first protrusions 51B and multiple second protrusions 52B are arranged at intervals in the axial direction, the first radial magnet 1B is supported by the multiple first protrusions 51B and the multiple second protrusions 52B, thereby further preventing the first radial magnet 1B from falling off.

[0056] FIG. 9 is a schematic diagram showing a detailed example of the first divided magnet 111B and the second divided magnet 222B. Although not a required component of the present disclosure, both the first magnet end face 115 and the second magnet end face 125 may be inclined toward the first side as they move radially inward. When the first magnet end face 115 and the second magnet end face 125 are in direct or indirect contact with each other, a force F3 directed radially outward acts from the first magnet end face 115 to the second magnet end face 125. This can further suppress the first radial magnet 1 from falling off.

[0057] <Details of the First Protrusion 51 and the Second Protrusion 52 (Third Embodiment)> Fig. 10 is a schematic diagram of a stator 20C (20) according to a third embodiment. Fig. 10 shows the stator 20C as viewed from the inside in the radial direction, and the circumferential direction is illustrated so as to coincide with the lateral direction of the page. Fig. 11 is a schematic diagram of a first radial magnet 1C (1) according to the third embodiment.

[0058] The stator 20C includes a stator core 24C (24). The stator core 24C includes a plurality of first projections 51C (51) spaced apart in the axial direction, and a plurality of second projections 52C (52) spaced apart in the axial direction. The axial length of each of the first projections 51C and the axial length of each of the second projections 52C are the same. In addition, the axial range in which the plurality of first projections 51C are arranged is different from the axial range in which the plurality of second projections 52C are arranged. For example, such a stator 20C may have a configuration in which a plurality of types of laminated steel plates are laminated. The plurality of types of laminated steel plates include a third laminated steel plate for forming the first projections 51C and a fourth laminated steel plate for forming the second projections 52C.

[0059] As shown in FIG. 11, the first radial magnet 1C(1) according to the third embodiment includes a first divided magnet 111C(111) and a second divided magnet 222C(222) arranged so as to be stacked in the axial direction. In this example, the first divided magnets 111C and the second divided magnets 222C are arranged so as to be alternately stacked in the axial direction. The first divided magnet 111C engages with the first protrusion 51C, and the second divided magnet 222C engages with the second protrusion 52C. Both the first divided magnet 111C and the second divided magnet 222C are examples of stacked permanent magnets 12 (see FIG. 16) constituting the magnet 5.

[0060] Each of the first divided magnets 111C (111) has a first inclined surface 61 and a first connecting surface 63. On the other hand, the second divided magnet 222C (222) has a second inclined surface 62 and a second connecting surface 64. The other end face in the circumferential direction of the first divided magnet 111C is flush with the second connecting surface 64 of the second divided magnet 222C. The one end face in the circumferential direction of the second divided magnet 222C is flush with the first connecting surface 63 of the first divided magnet 111C.

[0061] With reference to Fig. 10 and Fig. 12, an assembly method of the first radial magnet 1C according to the third embodiment is illustrated. Fig. 12 is a schematic diagram showing an assembly process of the first radial magnet 1C. As shown in Fig. 12, the first radial magnet 1C is disposed radially inward of the first protrusion 51C and the second protrusion 52C. At this time, the first divided magnet 111C is shifted in the axial direction from the first protrusion 51C, and the second divided magnet 222C is shifted in the axial direction from the second protrusion 52C.

[0062] Next, the first radial magnet 1C is moved axially outward until it contacts the tooth inner circumferential surface 259 (see FIG. 12). At this time, the first split magnet 111C is offset in the axial direction from the first protrusion 51C, and the second split magnet 222C is offset in the axial direction from the second protrusion 52C. Therefore, interference between the first split magnet 111C and the first protrusion 51C, and between the second split magnet 222C and the second protrusion 52C can be avoided.

[0063] Thereafter, the first radial magnet 1C is slid in the axial direction (arrow E1 in FIG. 12), the first divided magnet 111C is engaged with the first protrusion 51C, and the second divided magnet 222C is engaged with the second protrusion 52C (see FIG. 10). As a result, the first radial magnet 1C is assembled to the first protrusion 51C and the second protrusion 52C. By repeatedly carrying out such assembly, a plurality of first radial magnets 1C are assembled to the stator core 24C in the circumferential direction.

[0064] According to the above configuration, the first radial magnet 1C is divided into the first divided magnet 111C and the second divided magnet 222C as the multiple permanent magnets 12, so that the eddy current loss generated in the first radial magnet 1C can be reduced. In addition, the axial length of each of the first protrusion 51C and the second protrusion 52C can be made shorter than the axial length of the tooth 25, so that the configuration of the stator core 24C can be further simplified. Furthermore, in the assembly process of the stator 20C, the first radial magnet 1C can be moved from the radial inside to the radial outside in a state in which the first divided magnet 111C is shifted in the axial direction from the first protrusion 51C and the second divided magnet 222C is shifted in the axial direction from the second protrusion 52C, so that the first radial magnet 1C can be brought into contact with the tooth inner peripheral surface 259, which is an example of the core inner peripheral surface 26. Thereafter, the first radial magnet 1C is slid in the axial direction (arrow E1 in FIG. 12) to engage the first divided magnet 111C with the first protrusion 51C and the second divided magnet 222C with the second protrusion 52C, thereby attaching the first radial magnet 1C to the stator core 24C. Since the amount of sliding of the first radial magnet 1C in the axial direction can be reduced, it is also possible to facilitate the assembly of the stator 20C. The number of first protrusions 51B and the number of second protrusions 52B may each be 1. Even in this case, the above-mentioned advantages can be obtained.

[0065] <Other magnets 5> Returning to Fig. 3, the second radial magnet 2 is supported by the third protrusion 53 and the fourth protrusion 54. As described above, the second radial magnet 2 has the same shape as the first radial magnet 1, and the third protrusion 53 and the fourth protrusion 54 have the same shapes as the first protrusion 51 and the second protrusion 52, respectively.

[0066] 4, the shape of the first circumferential magnet 3 will be described. One end face in the circumferential direction of the first circumferential magnet 3 has a first inclined extending surface 131 and a first extending surface 135, and the other end face in the circumferential direction has a second inclined extending surface 132 and a second extending surface 136.

[0067] The first inclined extending surface 131 and the second inclined extending surface 132 extend at an incline so as to move away from the center in the circumferential direction of the first circumferential magnet 3 as they move inward in the radial direction. The inner end portions of the first inclined extending surface 131 and the second inclined extending surface 132 in the radial direction are located radially inward from the protrusion 50. The first extending surface 135 extends radially inward from the inner end portion in the radial direction of the first inclined extending surface 131 and abuts against the second radial magnet 2. An adhesive may be interposed between the first extending surface 135 and the second radial magnet 2. Similarly, the second extending surface 136 extends radially inward from the inner end portion in the radial direction of the second inclined extending surface 132 and abuts against the first connecting surface 63 of the first radial magnet 1. An adhesive may be interposed between the second extending surface 136 and the first connecting surface 63.

[0068] The first inclined extension surface 131 abuts against the fourth protrusion 54, and the second inclined extension surface 132 abuts against the first protrusion 51. An adhesive may be interposed between the first inclined extension surface 131 and the fourth protrusion 54, and between the second inclined extension surface 132 and the first protrusion 51. As described above, a magnetic force acting radially outward acts on the first circumferential magnet 3 (arrow A3 in FIG. 3), and the first circumferential magnet 3 is pressed against the first protrusion 51 and the fourth protrusion 54.

[0069] The shape of the second circumferential magnet 4 will be described. One end face in the circumferential direction of the second circumferential magnet 4 has a third inclined extending surface 133 and a third extending surface 137, and the other end face in the circumferential direction has a fourth inclined extending surface 134 and a fourth extending surface 138.

[0070] The third inclined extending surface 133 and the fourth inclined extending surface 134 extend at an incline so as to move away from the center in the circumferential direction of the second circumferential magnet 4 as they move inward in the radial direction. The radial inner end of each of the third inclined extending surface 133 and the fourth inclined extending surface 134 is located radially inward from the protrusion 50. The third extending surface 137 extends radially inward from the radial inner end of the third inclined extending surface 133 and abuts against the second connecting surface 64 of the first radial magnet 1. An adhesive may be interposed between the third extending surface 137 and the second connecting surface 64. Similarly, the fourth extending surface 138 extends radially inward from the radial inner end of the fourth inclined extending surface 134 and abuts against the second radial magnet 2. An adhesive may be interposed between the fourth extending surface 138 and the second circumferential magnet 4.

[0071] The third inclined extension surface 133 abuts against the second protrusion 52, and the fourth inclined extension surface 134 abuts against the third protrusion 53. An adhesive may be interposed between the third inclined extension surface 133 and the second protrusion 52, and between the fourth inclined extension surface 134 and the third protrusion 53. As described above, a magnetic force acting radially outward acts on the second circumferential magnet 4 (arrow A4 in FIG. 3), so that the second circumferential magnet 4 is pressed against the second protrusion 52 and the third protrusion 53. The second circumferential magnet 4 has the same shape as the first circumferential magnet 3.

[0072] <Plate 70> 13A to 13C are schematic diagrams showing a plurality of magnets 5. In FIG. 13A to FIG. 13C, the circumferential direction is illustrated linearly, and the leftmost magnet 5 and the rightmost magnet 5 are adjacent to each other in the circumferential direction. In FIG. 13A to FIG. 13C, the near side of the paper is the radially inner side, and the far side of the paper is the radially outer side. FIG. 13A to FIG. 13C each diagrammatically illustrates a plate 70A (70) according to a first example, a plate 70B (70) according to a second example, and a plate 70C (70) according to a third example.

[0073] As shown in FIG. 13A to FIG. 13C, the plates 70A to 70C (70) extend in the circumferential direction. The plates 70A to 70C (70) are attached to the inner peripheral surface 15 of each of the two or more magnets 5 arranged continuously in the circumferential direction, for example, by adhesive. The two or more magnets 5 arranged continuously include the first radial magnet 1. The plates 70A to 70C (70) are formed of a nonmagnetic material. This makes it possible to suppress the flow of eddy currents in the plates 70, and to suppress iron loss in the stator 20. The plates 70 are preferably made of a nonmagnetic and nonconductive material. Examples of such materials include glass fiber reinforced plastics (GFRP), carbon fiber reinforced plastics (CFRP), and heat-resistant resin.

[0074] In the example of FIG. 13A, a plurality of plates 70A are arranged at equal intervals in the circumferential direction. The magnets 5 to which each plate 70A is attached include a first radial magnet 1 and a second radial magnet 2. In the example of the figure, the number of magnets 5 to which the plate 70A is attached is four or more, more specifically, four. The plate 70B shown in FIG. 13B is attached to the inner circumferential surface 15 of each of the plurality of magnets 5 over the entire circumferential length of the stator core 24 (see FIG. 2). In other words, the plate 70B is a single cylindrical member attached to the inner circumferential surface 15 of each of all the magnets 5 constituting the stator 20. In the example shown, the two plates 70B are attached to one end side and the other end side of the magnet 5 in the axial direction, respectively. Note that one plate 70B may be arranged so that one axial end of the magnet 5 and one axial end of the plate 70B are aligned. Similarly, the other plate 70B may be disposed so that the other axial end of the magnet 5 and the other axial end of the plate 70B are aligned.

[0075] The plate 70C shown in FIG. 13C includes a first plate portion 71 attached to the two or more magnets 5 described above, and a second plate portion 72 longer than the first plate portion 71 in the circumferential direction. The first plate portion 71 and the second plate portion 72 are integrally configured, and the second plate portion 72 is connected to one end of the first plate portion 71 in the axial direction. The number of magnets 5 to which the second plate portion 72 is attached is greater than the number of magnets 5 to which the first plate portion 71 is attached. More specifically, the magnets 5 to which the second plate portion 72 is attached include the magnet 5 to which the first plate portion 71 is attached and at least one other magnet 5. In the example of the figure, the second plate portion 72 is attached to all magnets 5 constituting the stator 20, and the number of magnets 5 to which the first plate portion 71 is attached is four. In the example of the figure, a plurality of first plate portions 71 are arranged at equal intervals in the circumferential direction. 13C, may be one. Alternatively, the number of plates 70C is not limited to one, but may be two or more. In this case, a plurality of second plate portions 72 are disposed at equal intervals in the circumferential direction, and a plurality of first plate portions 71 are connected to each of the second plate portions 72.

[0076] According to the configuration in which the stator 20 includes the plate 70A (70), the four magnets 5 are integrated by the plate 70A, so that the first protrusions 51 and the second protrusions 52 can support not only the first radial magnet 1 but also other magnets 5 such as the first circumferential magnet 3 or the second circumferential magnet 4. This realizes a stator 20 that can further prevent the multiple magnets 5 from falling off. The above advantages can also be obtained when plates 70B and 70C are used instead of plate 70A. For example, when plate 70B is used, all of the magnets 5 constituting the stator 20 are integrated by the attachment of plate 70B, and the magnets 5 are prevented from falling off.

[0077] Furthermore, according to a configuration in which the magnets 5 attached to the plate 70A include the first radial magnet 1 and the second radial magnet 2, the plate 70A is attached to multiple magnets 5, including the first radial magnet 1 and the second radial magnet 2, which are two magnets 5 that have a relatively high risk of falling off, so that the multiple magnets 5 can be more reliably prevented from falling off.

[0078] Furthermore, since plate 70C includes first plate portion 71 and second plate portion 72, it is possible to attach second plate portion 72 to a location where the temperature rises slowly, and attach first plate portion 71 to a location where the temperature rises rapidly. This makes it possible to prevent integrated magnet 5 from falling off, and also to prevent damage to plate 70C caused by thermal deformation.

[0079] <Assembling method of the stator 20> A method for assembling the stator 20 will be described with reference to Figs. 14 and 15. In the following description, "step" may be abbreviated as "S". Fig. 14 is a flowchart of a method for assembling the stator 20 according to an embodiment of the present disclosure. Fig. 15 is a schematic diagram showing a process of a radial magnet placement step (S11) according to an embodiment of the present disclosure. The assembly described below is performed by a worker, a robot arm operated by a worker, or a combination thereof. At the start of assembly, the holding member 209 is already placed (see Fig. 15).

[0080] First, a radial magnet arrangement step (S11) is performed in which the first radial magnets 1 and the second radial magnets 2 are arranged in the stator core 24.

[0081] The radial magnet arranging step (S11) includes a first radial magnet arranging step of arranging the first radial magnets 1 and a second radial magnet arranging step of arranging the second radial magnets 2. In the first radial magnet arrangement step, each of the multiple first radial magnets 1 is assembled to the first protrusions 51 and the second protrusions 52. Details of this assembly process are as described above. In this assembly process, an adhesive may be used to adhere the first radial magnets 1 to the first protrusions 51 and the second protrusions 52. In the second radial magnet arrangement step, each of the multiple second radial magnets 2 is assembled to the third protrusion 53 and the fourth protrusion 54. This assembly step is similar to the first radial magnet arrangement step, and is realized by sliding the second radial magnet 2 in the axial direction to engage the second radial magnet 2 with the third protrusion 53 and the fourth protrusion 54. In this assembly step, an adhesive may be used to adhere the second radial magnet 2 to the third protrusion 53 and the fourth protrusion 54.

[0082] During the execution of S11, the first radial magnet 1 and the second radial magnet 2 arranged on the stator core 24 receive magnetic forces in a direction approaching each other in the circumferential direction (arrow W). This is because the radially inner end of the first radial magnet 1 has an S pole, and the inner end of the second radial magnet 2 has an N pole. Furthermore, the outer end of the first radial magnet 1 has an N pole, and the outer end of the second radial magnet 2 has an S pole. As a result, each protrusion 50 receives a force in the circumferential direction from the first radial magnet 1 and the second radial magnet 2. In this regard, if the radial length of the protrusion 50 is configured to be 25% or less of the radial length of the first radial magnet 1 and the second radial magnet 2, the bending moment generated in the protrusion 50 can be reduced, and damage to the protrusion 50 can be suppressed.

[0083] When S11 is completed (i.e., when the first radial magnets 1 and the second radial magnets 2 are arranged at equal intervals over the entire circumferential length of the stator 20), the bending moment generated in each protrusion 50 almost disappears. This is because the magnetic forces acting on the first radial magnets 1 and the second radial magnets 2 cancel each other out in the circumferential direction.

[0084] After completion of S11, an assembly jig (not shown) may be temporarily arranged to fix the first radial magnet 1 and the second radial magnet 2 at the assembly position. As one example, the assembly jig presses the first radial magnet 1 and the second radial magnet 2 from the inside to the outside in the radial direction.

[0085] Next, a circumferential magnet arrangement step (S13) is performed to arrange the first circumferential magnet 3 and the second circumferential magnet 4 in the stator core 24. For example, each of the first circumferential magnets 3 is arranged between the first protrusion 51 and the fourth protrusion 54, and each of the second circumferential magnets 4 is arranged between the second protrusion 52 and the third protrusion 53. More specifically, the first circumferential magnet 3 and the second circumferential magnet 4 are moved from the inside to the outside in the radial direction and arranged in a predetermined assembly position. Note that, when S13 is performed, an adhesive for bonding the first circumferential magnet 3 to the first protrusion 51 and the fourth protrusion 54, and an adhesive for bonding the second circumferential magnet 4 to the second protrusion 52 and the third protrusion 53 may be used. By performing S13, the first circumferential magnet 3 and the second circumferential magnet 4 are arranged in the stator core 24 (see FIG. 3).

[0086] Next, a plate arrangement step (S15) is performed in which the plate 70 is arranged on the inner circumferential surface 15 of two or more consecutively arranged magnets 5. The plate 70 is attached to the inner circumferential surface 15 via, for example, an adhesive. This completes the assembly method for the stator 20.

[0087] <Another embodiment (first example)> 16, a stator 20 according to another embodiment will be described. The stator 20 may further include a pressing member 80. The number of pressing members 80 in this example is the same as the number of magnets 5 constituting the stator 20.

[0088] Each magnet 5 constituting the stator 20 includes a plurality of permanent magnets 12 stacked in the axial direction. That is, each of the first radial magnet 1, the second radial magnet 2, the first circumferential magnet 3, and the second circumferential magnet 4 includes a plurality of permanent magnets 12. The pressing member 80 presses the inner circumferential surface 15 of each permanent magnet 12 radially outward. An example of a more specific configuration is as follows.

[0089] The permanent magnet 12 includes a first permanent magnet 121 located closest to a first side in the axial direction and a second permanent magnet 122 located closest to a second side opposite to the first side, the first permanent magnet 121 having a first surface 121A facing the first side, and the second permanent magnet 122 having a second surface 122A facing the second side. Note that the first divided magnet 111 or the second divided magnet 222 shown in FIG. 6, FIG. 10, etc. may be the first permanent magnet 121 or the second permanent magnet 122.

[0090] Stator 20 further includes a first reel 91 provided on first surface 121A and a second reel 92 provided on second surface 122A. The first reel 91 includes a first joint portion joined to the first surface 121A and a first columnar portion provided at the first joint portion. The first columnar portion extends linearly along the circumferential direction and faces the first surface 121A in the axial direction with a gap therebetween. The first columnar portion may be fixed to the first joint portion or may be rotatably provided at the first joint portion. Also, a first cylindrical portion may be provided instead of the first columnar portion. The second reel 92 includes a second joint portion joined to the second surface 122A and a second columnar portion provided at the second joint portion. The second columnar portion extends linearly along the circumferential direction and faces the second surface 122A in the axial direction with a gap therebetween. The second columnar portion may be fixed to the second joint portion or may be rotatably provided at the second joint portion. Also, a second cylindrical portion may be provided instead of the second columnar portion.

[0091] The pressing member 80 in this example is a wire 89 that binds together the first reel 91, the second reel 92, and each of the plurality of permanent magnets 12. The wire 89 is made of CFRP or GFRP.

[0092] The wire 89 includes a first winding portion 81 wound around a first reel 91, a first axially extending portion 83 pulled out from the first reel 91, a bent portion 85 connected to the first axially extending portion 83 and bent by contacting the second reel 92, a second axially extending portion 84 connected to the bent portion 85, and a second winding portion 82 connected to the second axially extending portion 84 and wound around the first reel 91. Note that, for ease of viewing the drawings, the second winding portion 82 is illustrated apart from the first reel 91, but the second winding portion 82 is actually wound around the first cylindrical portion of the first reel 91. For the same reason, the first axially extending portion 83 is illustrated apart from the inner circumferential surface 15 of the permanent magnet 12, but the first axially extending portion 83 actually contacts the inner circumferential surface 15.

[0093] The first winding portion 81 is wound around the first cylindrical portion of the first reel 91. The first axially extending portion 83 extends in the axial direction and abuts against the inner circumferential surface 15 of each of the permanent magnets 12 from the radially inner side. More specifically, a groove (not shown) extending in the axial direction is provided on the inner circumferential surface 15 of each of the permanent magnets 12, and the first axially extending portion 83 is disposed inside the groove. The first axially extending portion 83 presses each of the inner circumferential surfaces 15 radially outward. The bent portion 85 abuts against approximately half of the outer circumferential surface of the second cylindrical portion of the second reel 92. The bent portion 85 according to another example may be wound around the second reel 92. The second axially extending portion 84 extends in the axial direction radially outward from the first axially extending portion 83. In this example, a hole is formed in each permanent magnet 12, and the second axially extending portion 84 is disposed inside the hole. In another example, the second axially extending portion 84 may be disposed so as to abut against the outer circumferential surface of the tooth 25 (more specifically, the outer circumferential surface of the tip portion 252 shown in FIG. 2).

[0094] According to the configuration in which the stator 20 includes the pressing member 80, each permanent magnet 12 is pressed radially outward, so that at least one of the multiple permanent magnets 12 constituting each magnet 5 can be prevented from falling off. In particular, according to the configuration in which the pressing member 80 presses the multiple permanent magnets 12 of the first radial magnet 1, the first radial magnet 1, which has a relatively high risk of falling off, is pressed, so that at least one of the multiple permanent magnets 12 constituting the first radial magnet 1 can be prevented from falling off. Similarly, according to the configuration in which the pressing member 80 presses the multiple permanent magnets 12 constituting the second radial magnet 2, the second radial magnet 2, which has the second highest risk of falling off after the first radial magnet 1, is pressed, so that at least one of the multiple permanent magnets 12 constituting the second radial magnet 2 can be prevented from falling off. The pressing member 80 is not limited to the wire 89. For example, it may be a rubber band arranged to bind the stator core 24 and the multiple permanent magnets 12. The above advantages can be obtained in this embodiment as well. Also, at least one of the pressing member 80 pressing the first circumferential magnet 3 and the pressing member 80 pressing the second circumferential magnet 4 does not need to be provided. That is, the number of pressing members 80 may be less than the number of magnets 5 constituting the stator 20.

[0095] Furthermore, according to a configuration in which the pressing member 80 is the wire 89 that binds the first reel 91, the second reel 92, and each of the multiple permanent magnets 12, the second axially extending portion 84 presses each of the multiple permanent magnets 12 radially outward due to the tension of the wire 89 that is generated by winding the wire 89 around at least one of the first reel 91 or the second reel 92. This makes it possible to prevent at least one of the multiple permanent magnets 12 that constitute each magnet 5 from falling off.

[0096] <Another embodiment (second example)> The magnet group arranged in the Halbach array may be eight magnets 5 arranged continuously in the circumferential direction. In this case, the arrangement is a so-called dual Halbach array, and the magnetization direction components of the first circumferential magnet 3 and the second circumferential magnet 4 adjacent to the first radial magnet 1 in the circumferential direction each have not only a circumferential component but also a radial component.

[0097] <Summary> The contents described in the above-mentioned embodiments can be understood, for example, as follows.

[0098] 1) A stator (20) according to one embodiment of the present disclosure includes: A stator core (24, 28), A plurality of magnets including a magnet group (for example, four magnets 5 arranged continuously in the circumferential direction) arranged continuously in the circumferential direction on the inner circumferential side of the stator core, the magnet group being arranged in a Halbach array (5); A stator comprising: The magnet group includes a first radial magnet (1) magnetized radially outward, The first radial magnet is An outer peripheral surface (65); a first inclined surface (61) that is connected to one end (65a) of the outer circumferential surface in the circumferential direction and inclined toward the center (virtual line K1) of the first radial magnet in the circumferential direction as it moves toward the inside in the radial direction; a second inclined surface (62) connected to the other end (65b) of the outer circumferential surface in the circumferential direction and inclined toward the center of the first radial magnet as it moves toward the inside in the radial direction; having The stator core is a core inner peripheral surface (26) on which the plurality of magnets are arranged; a first protrusion (51) protruding inward in the radial direction from the core inner peripheral surface and having a first support surface (55) that supports the first inclined surface; a second protrusion (52) protruding inward in the radial direction from the core inner peripheral surface and having a second support surface (56) that supports the second inclined surface; Including, Both the first support surface and the second support surface are inclined with respect to the radial direction, and are inclined toward the center side of the first radial magnet as they move inward in the radial direction.

[0099] According to the configuration of 1) above, since the first support surface and the second support surface are inclined with respect to the radial direction, the radially outward forces (F1, F2) acting on the first radial magnet from each of the first support surface and the second support surface can be increased, and the first radial magnet can be prevented from falling off. In addition, since the force acting on the first radial magnet can be increased without increasing the radial length of each of the first support surface and the second support surface, the radial length of each of the first protrusions and the second protrusions can be shortened, and the configuration of the stator core can be simplified. As described above, a stator that can prevent at least one of the multiple magnets from falling off with a simple configuration is realized.

[0100] 2) In some embodiments, the stator according to 1) above, The first radial magnet includes a first divided magnet (5) and a second divided magnet (5) arranged so as to be stacked in the axial direction, the first divided magnet has the first inclined surface and the second inclined surface, and is supported by the first protrusion and the second protrusion; The second split magnet is positioned so as to be offset from the first protrusion and the second protrusion in the axial direction, and is positioned between the tip (511) of the first protrusion and the tip (522) of the second protrusion in the circumferential direction.

[0101] According to the configuration of 2) above, since the first radial magnet is divided into a plurality of permanent magnets, the eddy current loss generated in the first radial magnet can be reduced. In addition, since the axial length of each of the first and second protrusions can be made shorter than the axial length of the teeth, the configuration of the stator core can be further simplified. Furthermore, in the assembly process of the stator, the first radial magnet can be moved from the inside to the outside in the radial direction while the first divided magnet is axially shifted from the first and second protrusions, so that the first radial magnet can be brought into contact with the inner peripheral surface of the core. Thereafter, the first radial magnet can be slid in the axial direction to engage the first divided magnet with the first and second protrusions, so that the first radial magnet can be attached to the stator core. Since the amount of sliding of the first radial magnet in the axial direction can be reduced, the assembly of the stator can also be facilitated.

[0102] 3) In some embodiments, the stator according to 1) above, The first radial magnet includes a first divided magnet (5) and a second divided magnet (5) arranged so as to be stacked in the axial direction, the first protrusion and the second protrusion are disposed at different positions from each other in the axial direction, the first divided magnet has the first inclined surface and is supported by the first protrusion, The second divided magnet has the second inclined surface and is supported by the second protrusion.

[0103] According to the above configuration 3), the first radial magnet is divided into a plurality of permanent magnets, so that the eddy current loss generated in the first radial magnet can be reduced. In addition, the axial length of each of the first and second protrusions can be made shorter than the axial length of the teeth, so that the configuration of the stator core can be further simplified. Furthermore, in the assembly process of the stator, the first radial magnet can be moved from the inside to the outside in the radial direction while the first divided magnet is shifted in the axial direction from the first protrusion and the second divided magnet is shifted in the axial direction from the second protrusion, so that the first radial magnet can be brought into contact with the inner peripheral surface of the core. Thereafter, the first radial magnet can be slid in the axial direction to engage the first divided magnet with the first protrusion and engage the second divided magnet with the second protrusion, so that the first radial magnet can be attached to the stator core. Since the amount of sliding of the first radial magnet in the axial direction can be reduced, it is also possible to facilitate the assembly of the stator.

[0104] 4) In some embodiments, the stator according to 2) or 3) above, The first radial magnet includes a plurality of the first divided magnets and a plurality of the second divided magnets stacked so as to be alternately arranged in the axial direction, The stator core is A plurality of the first protrusions arranged at intervals in the axial direction; a plurality of the second protrusions spaced apart in the axial direction; Includes.

[0105] According to the above configuration 4), the first radial magnets are supported by the multiple first protrusions and the multiple second protrusions, so that the first radial magnets can be further prevented from falling off.

[0106] 5) In some embodiments, the stator is as described in any one of 2) to 4) above, The first divided magnet has a first magnet end surface (115) which is an end surface on a first side in the axial direction, The second divided magnet has a second magnet end face (125) which is an end face on a second side in the axial direction and abuts against the first magnet end face, Both the first magnet end face and the second magnet end face are inclined toward the first side in the axial direction as they move inward in the radial direction.

[0107] According to the above configuration 5), a force acts radially outward from the first magnet end face of the first divided magnet supported by at least the first protrusion of the first or second protrusion to the second magnet end face of the second divided magnet. This prevents the second divided magnet from falling off. This further prevents the first radial magnet from falling off.

[0108] 6) In some embodiments, the stator according to 1) above, At least one of the first projection and the second projection extends continuously in the axial direction over the entire axial length of the inner circumferential surface of the core.

[0109] According to the above configuration 6), the axial range in which the first radial magnet is supported by at least one of the first protrusions or the second protrusions can be expanded, so that the first radial magnet can be further prevented from falling off.

[0110] 7) In some embodiments, the stator according to any one of 1) to 6) above, The stator core further includes a plurality of teeth spaced apart in the circumferential direction, The core inner peripheral surface includes a teeth inner peripheral surface (66) which is an inner peripheral surface of at least one of the plurality of teeth.

[0111] According to the above configuration 7), the first and second projections can be integrated with the plurality of teeth, so that the configuration of the stator can be further simplified.

[0112] 8) In some embodiments, the stator according to any one of 1) to 7) above, The magnet further includes a plate (70) extending in the circumferential direction and attached to an inner circumferential surface (5) of each of the two or more magnets including the first radial magnet.

[0113] According to the configuration of 8) above, the first radial magnet supported by the first and second protrusions is connected to another magnet via a plate, whereby the other magnet is also indirectly supported by the first and second protrusions, realizing a stator that can prevent multiple magnets from falling off.

[0114] 9) In some embodiments, the stator according to 8) above, The magnet group further includes a second radial magnet (2) magnetized inward in the radial direction, The magnets to which the plate is attached include the first radial magnet and the second radial magnet.

[0115] According to the above configuration 9), the plate is attached to multiple magnets, including the first radial magnet and the second radial magnet, which are two magnets that are relatively at risk of falling off, so that the multiple magnets can be more reliably prevented from falling off.

[0116] 10) In some embodiments, the stator according to 8) above, The plate is a single member attached to the inner circumferential surface of each of the plurality of magnets over the entire circumferential length of the stator core.

[0117] According to the above configuration 10), all the magnets are integrated by the plate, and the magnets are prevented from falling off.

[0118] 11) In some embodiments, the stator according to 10) above, The plate is a first plate portion (71) attached to the two or more magnets; a second plate portion (72) connected to one axial end of the first plate portion and longer than the first plate portion in the circumferential direction; Includes The magnets to which the second plate portion is attached include the two or more magnets to which the first plate portion is attached and at least one other magnet.

[0119] According to the above configuration 11), it is possible to attach the second plate part to the place where the temperature rises slowly, and attach the first plate part to the place where the temperature rises rapidly. This makes it possible to prevent the integrated magnet from falling off, and also to prevent the plate from being damaged due to thermal deformation.

[0120] 12) In some embodiments, the stator according to any one of 1) to 11) above, The first radial magnet includes a plurality of permanent magnets (12) stacked in the axial direction, The stator core further includes a pressing member (80) that presses the inner circumferential surface (5) of each permanent magnet outward in the radial direction.

[0121] According to the above configuration 12), the first radial magnet, which has a relatively high risk of falling off, is pressed radially outward, thereby preventing at least one of the multiple permanent magnets constituting the first radial magnet from falling off.

[0122] 13) In some embodiments, the stator according to 12) above, The plurality of permanent magnets are A first permanent magnet (5) located on the first side in the axial direction; A second permanent magnet (5) located on the second most side in the axial direction; and Including, The stator includes: a first reel (91) provided on a first surface (121A) of the first permanent magnet facing the first side; a second reel (92) provided on a second surface (122A) of the second permanent magnet facing the second side; Further equipped with The pressing member is a wire that binds the first reel, the second reel, and each of the plurality of permanent magnets.

[0123] According to the above configuration 13), the permanent magnets are pressed radially outward by tension generated by winding the wire around at least one of the first reel and the second reel, thereby making it possible to prevent at least one of the permanent magnets constituting the magnet from falling off.

[0124] 14) The magnetic gear electric machine (10) according to at least one embodiment of the present disclosure comprises: A stator (20) according to any one of 1) to 13) above; a pole piece rotor (30) including a plurality of pole pieces arranged in the circumferential direction on the radially inner side of the stator; a magnet rotor (40) including an inner magnet arranged radially inward of the plurality of magnetic pole pieces; Equipped with.

[0125] According to the configuration 14) above, the same advantages as those of 1) above can be obtained.

[0126] 15) A method of assembling a stator (20) according to at least one embodiment of the present invention, comprising the steps of: The method includes a step (S11) of sliding the first radial magnet (1) in the axial direction to engage the first inclined surface (61) with the first protrusion (51) and to engage the second inclined surface (62) with the second protrusion (52).

[0127] According to the configuration 15) above, the same advantages as those of 1) above can be obtained. [Explanation of symbols]

[0128] 1: First radial magnet 2: Second radial magnet 3: First circumferential magnet 4:Second circumferential magnet 5: Magnet 10: Magnetic gear electric machine 15: Inner surface 20: Stator 24,28: Stator core 25: Teeth 26: Inner surface of core 29: York 30: Pole piece rotor 40: Magnet rotor 50: Protrusion 51: 1st protrusion 52:Second protrusion 53: 3rd protrusion 54: 4th protrusion 55: 1st support surface 56:Second support surface 61: 1st slope 62:Second slope 65: Outer surface 65a: One end 65b: Other end 66: Inner surface 70: Plate 71: First plate section 72: Second plate section 80: Pressing member 91: 1st reel 92: 2nd reel 111: First divided magnet 115: First magnet end face 121: First permanent magnet 121A: 1st surface 122: Second permanent magnet 122A: 2nd surface 125: Second magnet end face 150: Mounting material 152: Extension part 161: Engagement hole 166: Engagement protrusion 170: Pressing rod 201: Slot opening 222: Second split magnet 259: Inner surface of teeth 511,522: Tip G1: Outer air gap G2: Inner air gap K1: Virtual line

Claims

1. A stator core; A plurality of magnets including a magnet group arranged continuously in a circumferential direction on the inner circumferential side of the stator core, the magnet group being a plurality of magnets arranged in a Halbach array; A stator comprising: The magnet group includes a first radial magnet magnetized radially outward; The first radial magnet is The outer periphery and a first inclined surface that is connected to one end of the outer circumferential surface in the circumferential direction and inclined toward the center of the first radial magnet in the circumferential direction as it moves toward the inside in the radial direction; a second inclined surface that is connected to the other end of the outer circumferential surface in the circumferential direction and inclined toward the center of the first radial magnet as it moves toward the inside in the radial direction; having The stator core is a core inner peripheral surface on which the plurality of magnets are arranged; a first protrusion protruding inward in the radial direction from the core inner circumferential surface, the first protrusion having a first support surface that supports the first inclined surface; a second protrusion protruding inward in the radial direction from the core inner circumferential surface and having a second support surface that supports the second inclined surface; Including, Both the first support surface and the second support surface are inclined with respect to the radial direction, and are inclined toward the center side of the first radial magnet as they move toward the inside in the radial direction. Stator.

2. The first radial magnet includes a first divided magnet and a second divided magnet arranged so as to be stacked in the axial direction, the first divided magnet has the first inclined surface and the second inclined surface, and is supported by the first protrusion and the second protrusion; The second divided magnet is disposed so as to be offset from the first projection and the second projection in the axial direction, and is disposed between the tip of the first projection and the tip of the second projection in the circumferential direction. The stator according to claim 1 .

3. The first radial magnet includes a first divided magnet and a second divided magnet arranged so as to be stacked in the axial direction, the first protrusion and the second protrusion are disposed at different positions from each other in the axial direction, the first divided magnet has the first inclined surface and is supported by the first protrusion, The second divided magnet has the second inclined surface and is supported by the second protrusion. The stator according to claim 1 .

4. The first radial magnet includes a plurality of the first divided magnets and a plurality of the second divided magnets stacked so as to be alternately arranged in the axial direction, The stator core is A plurality of the first protrusions arranged at intervals in the axial direction; a plurality of the second projections spaced apart in the axial direction; Includes 4. A stator according to claim 2 or 3.

5. The first divided magnet has a first magnet end surface which is an end surface on a first side in the axial direction, the second divided magnet has a second magnet end face on a second side in the axial direction, the second magnet end face being in contact with the first magnet end face, Both the first magnet end surface and the second magnet end surface are inclined toward the first side in the axial direction as they move toward the inside in the radial direction. The stator according to claim 3 .

6. At least one of the first projection and the second projection extends continuously in the axial direction over the entire axial length of the inner peripheral surface of the core. The stator according to claim 1 .

7. The stator core further includes a plurality of teeth spaced apart in the circumferential direction, The core inner peripheral surface includes a teeth inner peripheral surface which is an inner peripheral surface of at least one of the plurality of teeth. A stator according to any one of claims 1 to 3.

8. The magnet further includes a plate extending in the circumferential direction and attached to an inner circumferential surface of each of the two or more magnets, including the first radial magnet. A stator according to any one of claims 1 to 3.

9. The magnet group further includes a second radial magnet magnetized inward in the radial direction, The magnets to which the plate is attached include the first radial magnet and the second radial magnet.

9. The stator of claim 8.

10. The plate is a single member attached to the inner circumferential surface of each of the plurality of magnets over the entire length of the stator core in the circumferential direction.

9. The stator of claim 8.

11. The plate is A first plate portion attached to the two or more magnets; a second plate portion connected to one axial end of the first plate portion and longer than the first plate portion in the circumferential direction; Includes The magnets to which the second plate portion is attached include the two or more magnets to which the first plate portion is attached and at least one other magnet. The stator of claim 10.

12. The first radial magnet includes a plurality of permanent magnets stacked in the axial direction, The stator core further includes a pressing member that presses an inner circumferential surface of each permanent magnet outward in the radial direction. A stator according to any one of claims 1 to 3.

13. The plurality of permanent magnets are A first permanent magnet located on the first side in the axial direction; a second permanent magnet located on the second most side in the axial direction; Including, The stator includes: a first reel provided on a first surface of the first permanent magnet facing the first side; a second reel provided on a second surface of the second permanent magnet facing the second side; Further equipped with The pressing member is a wire that binds the first reel, the second reel, and each of the plurality of permanent magnets.

13. A stator according to claim 12.

14. A stator according to any one of claims 1 to 3; a pole piece rotor including a plurality of pole pieces arranged in the circumferential direction on the radially inner side of the stator; a magnet rotor including an inner magnet arranged radially inward of the plurality of magnetic pole pieces; 1. A magnetic gear electric machine comprising:

15. A method for assembling a stator according to any one of claims 1 to 3, comprising the steps of: A method for assembling a stator, comprising the steps of: sliding the first radial magnet in an axial direction to engage the first inclined surface with the first protrusion and to engage the second inclined surface with the second protrusion.

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