Stator and rotating electrical machine

Abstract

Provided are a stator and a rotating electrical machine that are more compact than the prior art. This stator is provided with: an annular stator core surrounding a central shaft and having a plurality of slots that are disposed at prescribed intervals in a circumferential direction around the central shaft and that extend in an axial direction parallel to the central shaft and in a radial direction; and a plurality of windings that include a plurality of segment conductors layered in a layering direction, which is the radial direction or the circumferential direction, and that are wound around the slots. Each of the segment conductors includes: a first segment conductor portion that is disposed at a coil end section which protrudes in the axial direction from an axial end surface of the stator core; and a pair of second segment conductor portions that are disposed in a pair of the slots, among the plurality of slots, that are mutually opposed. The first segment conductor portions of some of the segment conductors among the plurality of segment conductors are bent in the layering direction.

Description

Stator and rotating electric machine

[0001] The present disclosure relates to a stator and a rotating electric machine.

[0002] Conventionally, in order to shorten the length of a rotating electric machine in the direction of the rotation axis, it is known to use concentrated winding, in which a coil is wound around only one protrusion, rather than distributed winding, in which the coil is wound across multiple protrusions. For example, Patent Document 1 discloses a rotating electric machine that employs concentrated winding to shorten the coil end length in the direction of the rotation axis.

[0003] JP 2010-172195 A

[0004] In recent years, there has been a demand for rotating electrical machines to be made smaller while maintaining torque performance.

[0005] An object of the present disclosure is to provide a stator and a rotating electric machine that are smaller in size than those of the prior art.

[0006] A stator according to one aspect of the present disclosure includes: an annular stator core surrounding a central axis, the stator core having a plurality of slots arranged at predetermined intervals in the circumferential direction around the central axis and extending in an axial direction parallel to the central axis and in a radial direction; and a plurality of windings including a plurality of segment conductors stacked in a lamination direction, which is the radial or circumferential direction, and wound in each slot. Each segment conductor includes a first segment conductor portion arranged in a coil end portion that protrudes axially from an axial end face of the stator core, and a pair of second segment conductor portions arranged in a pair of opposing slots among the plurality of slots. The first segment conductor portions of some of the plurality of segment conductors are configured to bend in the lamination direction.

[0007] According to the present disclosure, it is possible to provide a stator and a rotating electric machine that are smaller in size than those of the prior art.

[0008] 10 is a schematic perspective view of a rotating electric machine according to a first embodiment. 11 is a schematic perspective view of a rotor according to the first embodiment. 12 is a schematic perspective view of a stator core according to the first embodiment. 13 is a schematic perspective view of an example of a winding according to the first embodiment. 14 is a schematic perspective view showing an example of a stator unit according to the first embodiment. 15 is a cross-sectional end view of the unit shown in FIG. 5 taken along line VI-VI. 16 is a cross-sectional end view of a portion of the unit shown in FIG. 5 taken along line VII-VII. 17 is a schematic perspective view of a portion of a unit of a comparative example. 18 is a cross-sectional end view of a portion of the unit shown in FIG. 15. 19 is a schematic cross-sectional view showing an example of a winding forming apparatus using an additive manufacturing method. 20 is a flowchart showing an example of a method of manufacturing the unit according to the first embodiment. 21 is a cross-sectional end view showing a portion of a unit in a first modified example of the stator unit according to the first embodiment. 22 is a schematic perspective view of a rotating electric machine according to a second embodiment. 23 is a schematic perspective view of a rotor according to the second embodiment. 24 is a schematic perspective view of a stator core according to the second embodiment. 25 is a schematic perspective view of an example of a winding according to the second embodiment. 24 is a schematic perspective view showing an example of a stator unit according to embodiment 2. FIG. 25 is a schematic perspective view showing an example of a stator unit according to embodiment 3. FIG. 26 is a cross-sectional end view taken along line XIX-XIX of a portion of the unit shown in FIG. 18. FIG. 27 is a cross-sectional end view showing a portion of a stator unit according to modification 2 of the stator unit according to embodiment 3. FIG. 28 is a cross-sectional end view showing a portion of a stator unit according to modification 3 of the stator unit according to embodiment 3. FIG. 29 is a cross-sectional end view showing a portion of a stator unit according to modification 4 of the stator unit according to embodiment 3. FIG. 29 is a schematic perspective view showing an example of a stator unit according to embodiment 4. FIG. 29 is a cross-sectional end view taken along line XXIV-XXIV of a portion of the unit shown in FIG. 23. FIG. 29 is a cross-sectional end view showing a portion of a stator unit according to modification 5 of the stator unit according to embodiment 4. FIG. 29 is a cross-sectional end view showing a portion of a rotating electric machine using modification 5. FIG. 29 is a cross-sectional end view showing a portion of a rotating electric machine using modification 5.

[0009] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. However, the configurations described below are merely examples of the present disclosure, and the present disclosure is not limited to the following embodiments. The technology in the present disclosure is not limited to these embodiments, and various modifications, substitutions, additions, omissions, etc. are possible depending on the design, etc., as long as they do not deviate from the technical concept of the present disclosure.

[0010] Although the present disclosure has been fully described in connection with the preferred embodiments with reference to the accompanying drawings, various changes and modifications will be apparent to those skilled in the art, and such changes and modifications are to be understood as included within the scope of the present disclosure as defined by the appended claims unless they depart therefrom.

[0011] In recent years, there has been a demand for miniaturization of rotating electric machines while maintaining high torque. A rotating electric machine includes a stator and a rotor that rotates relative to the stator via a predetermined gap. The stator includes a stator core and a plurality of windings wound around a portion of the stator core. Coil end portions, which represent the portions of the windings that protrude axially from the stator core, do not contribute to torque generation of the rotating electric machine. Therefore, shortening the axial length of the coil end portions allows the stator to be miniaturized while maintaining performance, and as a result, the rotating electric machine including the stator can be miniaturized.

[0012] A stator according to the present disclosure includes a stator core and a plurality of windings. Each of the plurality of windings includes segment conductors wound around a plurality of protrusions of the stator core and stacked in a predetermined direction. A predetermined group, which is a portion of the segment conductor portions located at the coil end portions of each segment conductor, is configured to bend in a predetermined direction. Another group, which is a portion of the segment conductor portions other than the predetermined group, is configured to bend in a direction opposite to the predetermined direction.

[0013] With this configuration, the stator can be configured so that the segment conductors located at the coil end portions are bent to shorten the axial length, thereby enabling the stator and the rotating electric machine including the stator to be miniaturized.

[0014] First Embodiment [Configuration] A rotating electric machine 1 according to a first embodiment of the present disclosure will be described with reference to FIGS. 1 to 4 . FIG. 1 is a schematic perspective view of the rotating electric machine 1 according to the first embodiment of the present disclosure. The rotating electric machine 1 represents a rotating electric machine. The rotating electric machine 1 is, for example, an electric motor. The rotating electric machine 1 may also be a generator. As shown in FIG. 1 , the rotating electric machine 1 includes a rotor 2 having a central axis 50 that is a rotation axis, and a stator 3 disposed radially outward of the rotor 2. The stator 3 is an annular stator including a stator core 30 and a plurality of windings 40. The rotating electric machine 1 also includes a housing (not shown). The rotor 2 and the stator 3 are housed within the housing. Note that in this specification, the radial direction refers to a direction extending radially from the central axis 50 on a plane perpendicular to the central axis 50. The radially inner side refers to a side closer to the central axis 50 in the radial direction. The radially outer side refers to a side farther from the central axis 50 in the radial direction.

[0015] Fig. 2 is a schematic perspective view of the rotor 2 according to the first embodiment of the present disclosure. As shown in Fig. 2, the rotor 2 includes a rotor core 20 and a shaft 21. The rotor 2 also includes a plurality of magnets 22. The rotor core 20 is disposed radially inside the stator core 30 with a predetermined gap therebetween. The rotor 2 is rotatable relative to the stator 3 about a central axis 50. The predetermined gap is an example of a first gap.

[0016] 3 is a schematic perspective view of stator core 30 according to the first embodiment of the present disclosure. As shown in FIG. 3 , stator core 30 has the same central axis 50 as rotor 2, and is configured in an annular shape surrounding central axis 50. Stator core 30 has a yoke 31, a plurality of protrusions 32, and a plurality of slots 33.

[0017] Yoke 31 is configured in an annular shape so as to surround central axis 50. Yoke 31 also extends in a cylindrical shape in the axial direction. In this specification, the axial direction means a direction parallel to central axis 50.

[0018] The multiple protrusions 32 are arranged on the inner peripheral side of the yoke 31 at predetermined intervals from one another in the circumferential direction around the central axis 50. The multiple protrusions 32 extend from the inner peripheral side of the yoke 31 toward the central axis 50 in a direction opposite to the radial direction. The multiple protrusions 32 also extend in the axial direction. Each protrusion 32 has a protrusion base 34 located on the radially outer side of the protrusion 32 and a protrusion end 35 located on the radially inner side of the protrusion 32. The protrusion base 34 extends from the yoke 31. In this specification, the circumferential direction means the direction along the circumference of a circle formed around the central axis 50.

[0019] The slots 33 are arranged on the inner peripheral side of the yoke 31 at predetermined intervals in the circumferential direction around the central axis 50. Each of the slots 33 extends in both the axial and radial directions. Each of the slots 33 is arranged between two adjacent protrusions 32 among the protrusions 32.

[0020] The stator 3 is formed by arranging a plurality of structures, each having the same shape, in a circular ring shape. Hereinafter, each of the structures constituting the stator 3 will be referred to as a unit 60. The unit 60 includes a part of the yoke 31, one of the plurality of protrusions 32, and the winding 40 wound around that one protrusion 32. The stator 3 has a plurality of units 60 connected in a circular shape. In other words, the unit 60 is one component constituting the stator 3.

[0021] FIG. 4 is a schematic perspective view of an example of winding 40 according to the first embodiment of the present disclosure. FIG. 4 shows winding 40 included in unit 60. The X-Y-Z coordinate system shown in the figure is provided to facilitate understanding of the invention and is not intended to limit the invention. The X-axis direction indicates the radial direction. The Y-axis direction indicates the tangential direction. The Z-axis direction indicates the axial direction. In this specification, the tangential direction refers to the direction perpendicular to the radial direction, among directions tangent to the circumference of a circle formed around central axis 50 on a plane perpendicular to central axis 50.

[0022] In the first embodiment, the winding 40, which is a coil, includes a plurality of segment conductors 41, which are flat wires with a rectangular cross section. The segment conductors 41 are stacked in the radial direction. In this specification, the direction in which the segment conductors 41 are stacked is also referred to as the stacking direction. The winding 40 is configured by connecting the segment conductors 41 in tandem with each other. For example, the winding 40 may be configured such that the segment conductors 41 are continuously connected in a spiral shape. In the rotating electric machine 1 according to the first embodiment, the stacking direction indicates the X-axis direction, i.e., the radial direction. The stacking direction may also be the opposite direction to the radial direction. The winding 40 is wound around the protrusion 32 so as to extend in the axial and tangential directions. The winding 40 is also wound in the slot 33 adjacent to the protrusion 32.

[0023] The stacked segment conductors 41 are spaced apart so as not to come into contact with each other. To prevent the segment conductors 41 from coming into contact with each other, the windings 40 may be formed so as to be wound around the protrusions 32 in the axial and tangential directions while gradually moving in the radial direction. Furthermore, to prevent the stacked segment conductors 41 from coming into contact with each other, the surfaces of the windings 40 are covered with an insulator.

[0024] The winding 40 is formed by a layered manufacturing method using additive manufacturing technology. The layered manufacturing method is also called an additive manufacturing method. The method of forming using additive manufacturing technology is not particularly limited, but examples include a powder bed method, a powder nozzle method, and a binder jet method. Each segment conductor 41 of the winding 40 is formed by the powder bed method.

[0025] Each segment conductor 41 includes a first segment conductor portion 43 and a pair of second segment conductor portions 42. The first segment conductor portion 43 indicates a portion of the segment conductor 41 that is arranged in a coil end portion that protrudes in the axial direction from the axial end face of the stator core 30. The second segment conductor portions 42 indicate portions of the segment conductor 41 that are arranged in a pair of opposing slots 33 among the multiple slots 33.

[0026] The coil end portions refer to portions of the winding 40 that protrude from the stator core 30 in a side view, that is, when the unit 60 is viewed in a direction perpendicular to the axis, for example, in the X-axis direction or the Y-axis direction. Each segment conductor 41 may have the first segment conductor portion 43 in the coil end portions located at both axial ends of the stator 3, or may have the first segment conductor portion 43 only in the coil end portion located at one axial end of the stator 3. In the first embodiment, each segment conductor 41 of the winding 40 included in the unit 60 has two first segment conductor portions 43 located at both axial ends of the protrusion 32 and two second segment conductor portions 42 located at both circumferential ends of the protrusion 32.

[0027] 4 , the winding 40 has two connection ends 44. The connection ends 44 are electrically connected to the connection ends 44 of the winding 40 in another unit 60, so that the winding 40 of each unit 60 is electrically connected to the winding 40 of another unit 60.

[0028] Fig. 5 is a schematic perspective view showing an example of a unit 60 of the stator 3 according to the first embodiment. As shown in Fig. 5, the first segment conductor portions 43 protrude from the axial end surface 36 of the projection 32. A pair of second segment conductor portions 42 are arranged in a pair of opposing slots 33. As shown in Fig. 5, the unit 60 is configured so that the first segment conductor portions 43 are bent in the radial direction or in the direction opposite to the radial direction.

[0029] 5, the winding 40 is wound around one of the plurality of protrusions 32. The winding 40 is also wound around the slot 33 adjacent to the protrusion 32.

[0030] Figure 6 is a cross-sectional end view of the unit 60 shown in Figure 5 taken along line VI-VI. Figure 6 shows an end view of the unit 60 cut along line VI-VI in Figure 5 by an imaginary plane perpendicular to the axial direction. Figure 6 also shows the cut end surfaces of a pair of second segment conductor portions 42 and the cut end surfaces of the projection 32 and the yoke 31. Hereinafter, in this specification, the imaginary plane perpendicular to the axial direction is also referred to as the "second plane."

[0031] In the example shown in FIG. 6 , the thicknesses of the second segment conductor portions 42 of each segment conductor 41 are different from one another. The second segment conductor portions 42 are formed so that the thickness increases as the segment conductor 41 is located radially inward, i.e., closer to the central axis 50. The thickness of the second segment conductor portions 42 indicates the plate thickness. For example, the thickness of the second segment conductor portions 42 is defined as at least one of the axial and radial dimensions of the segment conductor 41 located in the slot 33. Note that in the first embodiment, the thicknesses of the second segment conductor portions 42 are different from one another, but the thickness is not limited to this. For example, the thicknesses of the second segment conductor portions 42 may be substantially equal to one another in at least some of the second segment conductor portions 42 among the multiple second segment conductor portions 42. "Substantially equal thicknesses of the second segment conductor portions 42" may mean that the difference in thickness between the second segment conductor portions 42 is within 10% of the thickness, preferably within 5% of the thickness.

[0032] 6 , each segment conductor 41 is formed so that the thickness of the second segment conductor portion 42 is substantially uniform throughout. In other words, the second segment conductor portion 42 is formed so that the thickness of the second segment conductor portion 42 is constant. "Substantially uniform thickness of the second segment conductor portion 42" may mean that the difference in thickness of the second segment conductor portion 42 is within 10% of the thickness, and preferably within 5% of the thickness.

[0033] In the example shown in FIG. 6 , the conductor lengths of the second segment conductor portions 42 of each segment conductor 41 are different from one another. The conductor lengths of the second segment conductor portions 42 of each segment conductor 41 are configured to be longer for segment conductors 41 located radially outward, i.e., for segment conductors 41 farther from the central axis 50. For example, the conductor length of the second segment conductor portion 42 is defined as the dimension in the tangential direction of the segment conductor 41 located in the slot 33. Note that in the first embodiment, the conductor lengths of the second segment conductor portions 42 are different from one another, but the conductor length is not limited to this. For example, the conductor lengths of the second segment conductor portions 42 may be substantially equal to one another in at least some of the second segment conductor portions 42 among the multiple second segment conductor portions 42. The term "substantially equal conductor lengths of the second segment conductor portions 42" may mean that the difference in conductor length is within 10% of the conductor length, preferably within 5% of the conductor length.

[0034] The second segment conductor portions 42 of each segment conductor 41 are formed so that their cross-sectional areas in the second plane shown in FIG. 6 are substantially equal to each other. This cross-sectional area is an example of the second cross-sectional area. For example, the cross-sectional area in the second plane of the second segment conductor portion 42A located radially inward among the multiple second segment conductor portions 42 is substantially equal to the cross-sectional area in the second plane of the second segment conductor portion 42B located radially outward. The cross-sectional areas of the multiple second segment conductor portions 42 being substantially equal to each other may mean that the copper loss differences among the multiple second segment conductor portions 42 are similar to each other to the extent that they do not affect performance. Furthermore, the cross-sectional areas of the multiple second segment conductor portions 42 being substantially equal to each other may mean that the difference between the cross-sectional areas is within 10% of the cross-sectional area, preferably within 5% of the cross-sectional area. The same applies to the cross-sectional area of ​​the first segment conductor portion 43 described below. The same also applies to the cross-sectional areas of the second segment conductor portion 42 and the first segment conductor portion 43.

[0035] Figure 7 is a cross-sectional end view of a portion of the unit 60 shown in Figure 5 taken along line VII-VII. Figure 7 illustrates an end view showing a portion of the cut end surface of the unit 60 taken along line VII-VII in Figure 5, the cut end surface being parallel to the imaginary plane formed in the axial direction and the stacking direction. Figure 7 also illustrates the cut end surface of the first segment conductor portion 43, as well as the cut end surfaces of a portion of the protrusion 32 and a portion of the yoke 31. Hereinafter, in the first embodiment, the imaginary plane parallel to the imaginary plane formed in the radial direction, which is the stacking direction, and the axial direction is also referred to as the "first plane."

[0036] As described above, in the example shown in FIG. 7 , each of the multiple first segment conductor portions 43 is bent in the radial direction or the direction opposite to the radial direction. As shown in FIG. 7 , the first group of first segment conductor portions 43, which are some of the multiple first segment conductor portions 43, are bent toward the outer periphery of the stator core 30, i.e., in the radial direction. The radial direction is an example of a first direction. The second group of first segment conductor portions 43, which are some of the first segment conductor portions 43 other than the first group of first segment conductor portions 43, are bent toward the inner periphery of the stator core 30, i.e., in the direction opposite to the radial direction. In other words, the first group of first segment conductor portions 43 extend toward the outer periphery of the stator core 30. The second group of first segment conductor portions 43 extend toward the inner periphery of the stator core 30. The direction opposite to the radial direction is an example of a second direction.

[0037] By configuring the first segment conductor portion 43 in this manner, the protruding length of the first segment conductor portion 43 can be shortened compared to when the first segment conductor portion 43 is not bent. The protruding length of the first segment conductor portion 43 is defined as the axial dimension between the axial end portion of the first segment conductor portion 43 and the axial end face 36 of the stator core 30. The protruding length of the first segment conductor portion 43 may also be defined as the axial dimension of the segment conductor 41 located at the coil end portion.

[0038] The thickness of the first segment conductor portions 43 may vary. Specifically, the first segment conductor portions 43 are configured so that the thickness of the first segment conductor portions 43 varies in at least one of the axial and radial directions. That is, the first segment conductor portions 43 may be configured to have a non-uniform thickness. Furthermore, the first segment conductor portions 43 may have thicknesses different from each other. Furthermore, as shown in FIG. 7 , for example, at least some of the first segment conductor portions 43 among the plurality of first segment conductor portions 43 may have a constant thickness. At least other some of the first segment conductor portions 43 among the plurality of first segment conductor portions 43 may have different thicknesses. The thickness of all the first segment conductor portions 43 may be non-uniform.

[0039] 7, for example, the thickness of the first segment conductor portion 43C located farther from the stator core 30 in the axial direction is greater than the thickness of the first segment conductor portion 43C located closer to the stator core 30. The thickness of the first segment conductor portion 43 may be defined as the minimum value of the dimensions in a direction perpendicular to the tangent direction of the segment conductor 41 at the cut end surface of the segment conductor 41 cut along the first plane.

[0040] The first segment conductor portions 43 of each segment conductor 41 are formed so that their cross-sectional areas in the first plane shown in Fig. 7 are substantially equal to each other. This cross-sectional area is an example of the first cross-sectional area. For example, the cross-sectional area in the first plane of the first segment conductor portion 43C and the cross-sectional area in the first plane of the first segment conductor portion 43D, which is located radially inward among the multiple first segment conductor portions 43, are substantially equal to each other.

[0041] The protrusion length of the first segment conductor portion 43 can be shortened by increasing the thickness of a portion of the first segment conductor portion 43, as in the first segment conductor portion 43C. For example, the first segment conductor portion 43C is formed so that the thickness of the first segment conductor portion 43 is increased in a portion of the first segment conductor portion 43. This allows the first segment conductor portion 43C to be formed to have a predetermined cross-sectional area without bending so as to overlap the first segment conductor portion 43E located radially outward of the first segment conductor portion 43C.

[0042] This configuration can shorten the protruding length of the first segment conductor portions 43 compared to when the thickness of each first segment conductor portion 43 is constant. Furthermore, the copper loss in each first segment conductor portion 43 in each unit 60 of the stator 3 becomes substantially equal to each other, thereby suppressing differences in the amount of heat generated locally in the rotating electric machine 1.

[0043] Furthermore, the windings 40 of the stator 3 are formed so that the cross-sectional area of ​​the second segment conductor portion 42 in the second plane shown in Fig. 6 and the cross-sectional area of ​​the first segment conductor portion 43 in the first plane shown in Fig. 7 are substantially equal to each other. As a result, in each unit 60 of the stator 3, the copper losses in the second segment conductor portion 42 and the first segment conductor portion 43 are substantially equal to each other, and the occurrence of differences in the amount of heat generated locally in the rotating electric machine 1 can be suppressed.

[0044] (Comparative Example) A comparative example of the unit 60 in the first embodiment will be described. In the comparative example, differences from the example shown in Fig. 5 will be mainly described. In the comparative example, components that are the same as or equivalent to those in the example shown in Fig. 5 will be denoted by the same reference numerals. Also, in the comparative example, descriptions that overlap with those in the example shown in Fig. 5 may be omitted.

[0045] FIG. 8 is a schematic perspective view showing a portion of a unit 60 as a comparative example compared to the unit 60 of the stator 3 according to the first embodiment. Only a portion of the unit 60 is shown in FIG. 8 . Similar to the unit 60 shown in FIG. 5 , a pair of second segment conductor portions 42 of each segment conductor 41 of the winding 40 of the unit 60 of the comparative example are arranged in a pair of opposing slots 33 located at both circumferential ends of the projection 32. The first segment conductor portions 43 protrude from the axial end surface 36 of the projection 32. Also, similar to the unit 60 shown in FIG. 5 , in the unit 60 of the comparative example, the first segment conductor portions 43 protrude in the −Z direction from the axial end surface of the projection 32. The unit 60 shown in FIG. 8 differs from the unit 60 shown in FIG. 5 in that the first segment conductor portions 43 extend in the axial direction without bending in the radial direction or in the direction opposite to the radial direction.

[0046] Figure 9 is a cross-sectional end view taken along line IX-IX of a portion of the unit 60 shown in Figure 8. Figure 9 illustrates a cross-sectional end view of a portion of the unit 60 cut along line IX-IX in Figure 8 at a first plane. Figure 9 also illustrates the cut end surface of the first segment conductor portion 43 and the cut end surfaces of a portion of the projection 32 and the yoke 31. The end surface of the unit 60 of the comparative example taken along the second plane is configured similarly to that shown in Figure 6.

[0047] In the comparative example of the unit 60 shown in Fig. 9, the thicknesses of the first segment conductor portions 43 of each segment conductor 41 are different from each other. The first segment conductor portions 43 are formed so that the thickness of the segment conductor 41 located radially inward is greater. In the comparative example, the thickness of the first segment conductor portions 43 is defined as the radial dimension of the segment conductor 41. In the comparative example, the cross-sectional areas of the first segment conductor portions 43 in the first plane are formed to be substantially equal to each other.

[0048] In the comparative example of the unit 60 shown in Fig. 9, the protrusion length of the first segment conductor portion 43 of each segment conductor 41 is formed so that the more radially outward the segment conductor 41 is located, the greater the protrusion length. The protrusion length of the first segment conductor portion 43 is defined as the axial dimension between the axial end of the first segment conductor portion 43 and the axial end face 36 of the stator core 30. The protrusion length of the first segment conductor portion 43 may also be defined as the axial dimension of the segment conductor 41 located at the coil end portion.

[0049] In Fig. 7 , dimension D1 indicates the axial dimension between the axial end of the first segment conductor portion 43 that protrudes most axially from the stator core 30 and the axial end face 36 of the stator core 30 in the winding 40 according to embodiment 1. In Fig. 9 , dimension D2 indicates the axial dimension between the axial end of the first segment conductor portion 43 that protrudes most axially from the stator core 30 and the axial end face 36 of the stator core 30 in the winding 40 of the comparative example. As shown in Fig. 7 , dimension D1 can be made smaller than dimension D2 by bending the first segment conductor portion 43 in the radial direction or in the direction opposite to the radial direction and partially changing the thickness of the first segment conductor portion 43.

[0050] Furthermore, as shown in FIG. 7 , when the multiple first segment conductor portions 43 are bent in the same direction, the multiple first segment conductor portions 43 are stacked in the axial direction. Therefore, as the number of first segment conductor portions 43 increases, the protruding length of the first segment conductor portions 43 increases. As described above, the first group of first segment conductor portions 43 among the multiple first segment conductor portions 43 are bent in the radial direction. Furthermore, the second group of first segment conductor portions 43 among the multiple first segment conductor portions 43 are bent in the direction opposite to the radial direction. This configuration can reduce the number of first segment conductor portions 43 stacked in the axial direction. Therefore, with the configuration shown in FIG. 7 , the dimension D1 can be smaller than when the multiple first segment conductor portions 43 are bent in one direction.

[0051] FIG. 10 is a schematic cross-sectional view showing an example of a manufacturing apparatus 70 for manufacturing the winding 40 by additive manufacturing. As described above, the winding 40 is manufactured by the powder bed method. The powder bed method is also called powder bed fusion (PBF). As shown in FIG. 10 , the manufacturing apparatus 70 includes a tank 71 and a laser head 72. In the powder bed method, for example, metal powder 73 is spread in a predetermined tank 71, and the laser head 72 irradiates specific locations with a laser 74 to sinter the metal powder 73 located in those locations. The manufacturing apparatus 70 can gradually build up the manufactured object 75, i.e., the segment conductors 41 of the winding 40, by, for example, sintering the bottom layer of metal powder 73 in the manufactured object 75 and then sintering the layer of metal powder 73 above the bottom layer.

[0052] FIG. 11 is a flowchart showing an example of a method for manufacturing the unit 60 according to the first embodiment. First, for example, a molding device 70 molds the winding 40 to be assembled into the unit 60, which is composed of a plurality of segment conductors 41 (S11). Next, the surface of the winding 40 is insulated (S12). For example, the winding 40 can be insulated by applying an electrical insulating material such as enamel to the surface of each segment conductor 41. Next, the winding 40 is assembled to the protrusion base 34 of the stator core 30 (S13). At this point, the protrusions 32 of the stator core 30 only have the protrusion base 34 and do not have the protrusion end portion 35. Next, the protrusion end portion 35 is coupled to the protrusion base 34 (S14). The protrusion end portion 35 may be joined or welded to the protrusion base 34. The stator 3 can be manufactured by annularly combining a plurality of units 60 manufactured in this manner. The rotating electric machine 1 can be manufactured by axially inserting the rotor 2 into the stator 3.

[0053] Here, the method for manufacturing the unit 60 is not limited to the above, and the unit 60 may be manufactured by any method. For example, the winding 40 may be layered on a part of the yoke 31 and the protrusion base 34 so as to be wound around the protrusion base 34. The winding 40 may also be manufactured by an additive manufacturing method so that the conductor portion and the insulating layer of the segment conductor 41 are formed simultaneously. The protrusion end 35 may also be formed by an additive manufacturing method so as to be layered on the protrusion base 34.

[0054] The stator core 30 may be formed by an additive manufacturing method. For example, the stator core 30 may be formed using a directed energy deposition (DED) method. According to the directed energy deposition method, the stator core 30 may be formed by using a laser beam, an electron beam, or a plasma arc as a heat source, spraying metal powder from a nozzle in a concentrated manner, and melting the metal and spraying it out. Here, the manufacturing method of the stator core 30 by the additive manufacturing method is not limited to the directed energy deposition method, and the stator core 30 may be manufactured using a different method depending on the material and application. Similarly, the rotor core 20 may be formed by the additive manufacturing method.

[0055] (Variation 1) Variation 1 of the unit 60 in Embodiment 1 will be described. Variation 1 will mainly focus on differences from the example shown in Fig. 5. In Variation 1, components that are the same as or equivalent to those in the example shown in Fig. 5 will be denoted by the same reference numerals. Also, in Variation 1, descriptions that overlap with those in the example shown in Fig. 5 may be omitted.

[0056] Fig. 12 is a cross-sectional end view showing a portion of the unit 60 in Modification 1 of the unit 60 of the stator 3 according to Embodiment 1. Fig. 12 shows an end view showing a portion of the cut end surface of the unit 60 according to Modification 1, cut along a first plane similar to the end view shown in Fig. 7. Fig. 12 also shows the cut end surface of the first segment conductor portion 43 and the cut end surfaces of a portion of the projection 32 and the yoke 31. The end surface of the unit 60 shown in Fig. 12 in a second plane is configured similarly to that shown in Fig. 6.

[0057] In the first modification, the first segment conductor portions 43 are bent in the radial direction or in the direction opposite to the radial direction. For example, the first segment conductor portions 43 of the first group are bent toward the outer periphery of the stator core 30. The first segment conductor portions 43 of the second group are bent toward the inner periphery of the stator core 30. The first segment conductor portions 43 in the first modification differ from the first segment conductor portions 43 in the example shown in FIG. 7 in that the thickness of the first segment conductor portions 43 is constant.

[0058] Like the winding 40 of the unit 60 in the comparative example, the winding 40 in the first modification is formed so that the thickness of the first segment conductor portions 43 increases toward the radially inner side. Also, like the winding 40 described above, the winding 40 in the first modification is formed so that the cross-sectional areas of the first segment conductor portions 43 in the first plane shown in Fig. 12 are substantially equal to each other. This cross-sectional area is an example of a first cross-sectional area.

[0059] 12 , dimension D3 indicates the axial dimension between the axial end of the first segment conductor portion 43 that protrudes most axially from the stator core 30 and the axial end face 36 of the stator core 30 in the winding 40 according to Modification 1. As shown in FIG. 12 , by bending the first segment conductor portion 43 in the radial direction or the direction opposite to the radial direction, dimension D3 can be larger than dimension D1 but smaller than dimension D2.

[0060] In the present embodiment, the first segment conductor portion 43 is bent in two directions, but the bending directions of the first segment conductor portion 43 are not limited to these two directions. For example, the first segment conductor portion 43 may be configured to bend in one direction, that is, only radially inward or only radially outward. In this manner, the winding 40 may be configured so that at least a portion of the first segment conductor portion 43 is bent in at least one of the radial direction and the direction opposite to the radial direction. Furthermore, the winding 40 may be configured so that at least a portion of the first segment conductor portion 43 is bent in one of the radial direction and the direction opposite to the radial direction, and so that the thickness of at least a portion of the first segment conductor portion 43 is varied. With this configuration, for example, even if the dimension between the first segment conductor portion 43 located on the inner periphery of the stator core 30 and the inner periphery end face of the stator core 30 is small, the first segment conductor portion 43 can be formed so that its axial protrusion length is short.

[0061] [Effects] The stator 3 according to the first embodiment of the present disclosure can provide the following effects.

[0062] The stator 3 includes an annular stator core 30 surrounding a central axis 50 and a plurality of windings 40. The stator core 30 has a plurality of slots 33 arranged at predetermined intervals in the circumferential direction around the central axis 50 and extending in an axial direction parallel to the central axis 50 and in a radial direction. The plurality of windings 40 includes a plurality of segment conductors 41 stacked in a lamination direction, which is the radial direction, and are wound around each slot 33. Each segment conductor 41 includes a first segment conductor portion 43 arranged in a coil end portion that protrudes in the axial direction from an axial end face 36 of the stator core, and a pair of second segment conductor portions 42 arranged in a pair of opposing slots 33 among the plurality of segment conductors 41. The first segment conductor portions 43 of some of the plurality of segment conductors 41 are configured to bend in the lamination direction.

[0063] With this configuration, the axial protrusion length of the first segment conductor portion 43 arranged at the coil end portion of the winding 40 in the stator 3 can be shortened. In other words, the height of the first segment conductor portion 43 can be reduced compared to when the first segment conductor portion 43 is not bent. Therefore, the stator 3 can be made smaller in size.

[0064] Furthermore, in the stator 3, the first segment conductor portions 43 are configured so that their thickness varies in at least one of the axial, radial, and circumferential directions. This configuration allows each first segment conductor portion 43 of the winding 40 to have a non-uniform thickness. That is, some portions of the first segment conductor portions 43 can be configured to be thicker than other portions of the first segment conductor portions 43. This allows the protruding length of the first segment conductor portions 43 arranged at the coil end portions of the winding 40 to be shortened. This allows the stator 3 to be made smaller.

[0065] Furthermore, in the stator 3, the first cross-sectional areas of the first segment conductor portions 43 of each of the plurality of segment conductors 41, which are measured in a first plane parallel to a plane formed in the stacking direction and the axial direction, are substantially equal to each other. With this configuration, the copper losses in the first segment conductor portions 43 of the stator 3 can be substantially equal to each other. Therefore, the stator 3 can be miniaturized while maintaining its performance.

[0066] Furthermore, in the stator 3, the first cross-sectional area of ​​the first segment conductor portion 43 of each of the plurality of segment conductors 41, which is the first cross-sectional area in a first plane parallel to the plane formed in the stacking direction and the axial direction, is substantially equal to the second cross-sectional area of ​​the second segment conductor portion 42 of each of the plurality of segment conductors 41, which is the second cross-sectional area in a second plane perpendicular to the axial direction. With this configuration, in the stator 3, the copper loss in the first segment conductor portion 43 of the winding 40 and the copper loss in the second segment conductor portion 42 can be substantially equal to each other. Therefore, the stator 3 can be miniaturized while maintaining its performance.

[0067] Furthermore, in the stator 3, a first group of first segment conductor portions 43, which are a portion of the plurality of first segment conductor portions 43, are configured to bend in a first direction, which is the stacking direction. A second group of first segment conductor portions, which are a portion of the first segment conductor portions 43 other than the first group of first segment conductor portions 43, are configured to bend in a second direction opposite to the first direction. With this configuration, the protrusion length of the first segment conductor portions 43 can be shortened compared to when the first segment conductor portions 43 are bent in only one direction. This allows the stator 3 to be made smaller.

[0068] Furthermore, in the stator 3, the segment conductors 41 are stacked in the radial direction. The first direction is the radial direction, and the second direction is the direction opposite to the radial direction. With this configuration, the first segment conductor portions 43 of the first group are bent radially outward, and the first segment conductor portions 43 of the second group are bent radially inward. Therefore, the protruding length of the first segment conductor portions 43 can be shortened compared to when the first segment conductor portions 43 are bent only toward the inner periphery or only toward the outer periphery of the stator core 30. This allows the stator 3 to be made smaller.

[0069] Furthermore, in the stator 3, each winding 40 is wound in a concentrated winding manner. With this configuration, in a stator 3 in which the winding 40 is wound in a concentrated winding manner, the protruding length of the first segment conductor portion 43 can be shortened. Therefore, the stator 3 can be made smaller.

[0070] Furthermore, in the stator 3, each winding 40 is formed by additive manufacturing. By forming the winding 40 by additive manufacturing, the winding 40 can be formed in which at least a portion of the first segment conductor portion 43 is bent in the stacking direction. Furthermore, the first segment conductor portion 43 of each segment conductor 41 can be configured to have a non-uniform thickness. This allows the stator 3 to be made smaller.

[0071] The rotating electric machine includes the stator 3 described above, and a rotor 2 disposed radially inside the stator 3 with a predetermined gap therebetween and rotatable about a central axis 50. The stator 3 can be configured so that the protruding length of the first segment conductor portion 43 of the winding 40 is shortened, allowing the rotating electric machine 1 to be miniaturized.

[0072] (Embodiment 2) An overview of a rotating electric machine 1 in embodiment 2 will be described. In embodiment 2, differences from embodiment 1 will be mainly described. In embodiment 2, components that are the same as or equivalent to those in embodiment 1 will be described using the same reference numerals. Furthermore, in embodiment 2, descriptions that overlap with embodiment 1 may be omitted.

[0073] As described above, in the first embodiment, the windings 40 of the stator 3 are wound around the stator core 30 by concentrated winding. In the second embodiment, the rotating electric machine 1 according to the second embodiment differs from the rotating electric machine 1 according to the first embodiment in that the windings 40 of the stator 3 are wound around the stator core 30 by toroidal winding.

[0074] 13 is a schematic perspective view of a rotating electric machine 1 according to embodiment 2 of the present disclosure. As shown in FIG. 13 , the rotating electric machine 1 includes an annular rotor 2 having a central axis 50 that is the axis of rotation, and an annular stator 3 that includes a stator core 30 and a plurality of windings 40.

[0075] Fig. 14 is a schematic perspective view of a rotor 2 according to the second embodiment. As shown in Fig. 14, the rotor 2 includes an annular outer rotor core 20A and an annular inner rotor core 20B. The rotor 2 also includes a plurality of magnets 22 arranged in the outer rotor core 20A and the inner rotor core 20B. The outer rotor core 20A is arranged radially outward from the stator core 30 via a predetermined gap. The inner rotor core 20B is arranged radially inward from the stator core 30 via a predetermined gap. The rotor 2 is rotatable relative to the stator 3 about the central axis 50. The predetermined gap is an example of a first gap.

[0076] Fig. 15 is a schematic perspective view of a stator core 30 according to embodiment 2. As shown in Fig. 15, the stator core 30 has the same central axis 50 as the rotor 2, and is configured in an annular shape surrounding the central axis 50. The stator core 30 is disposed radially inward of the outer rotor core 20A and radially outward of the inner rotor core 20B, with a predetermined gap between the outer rotor core 20A and the inner rotor core 20B. The stator core 30 has a yoke 31, a plurality of protrusions 32, and a plurality of slots 33.

[0077] The yoke 31 is configured in an annular shape surrounding the central axis, and extends cylindrically in the axial direction.

[0078] Each protrusion 32 includes an outer protrusion 32A and an inner protrusion 32B. The outer protrusions 32A are arranged on the outer circumferential side of the yoke 31 at predetermined intervals from one another in the circumferential direction around the central axis 50. The outer protrusions 32A extend radially from the outer circumferential side of the yoke 31 away from the central axis 50. The inner protrusions 32B are arranged on the inner circumferential side of the yoke at predetermined intervals from one another in the circumferential direction around the central axis 50. The inner protrusions 32B extend from the inner circumferential side of the yoke 31 toward the central axis 50 in the direction opposite to the radial direction. The outer protrusions 32A and the inner protrusions 32B extend in the axial direction.

[0079] Each slot 33 includes an outer slot 33A and an inner slot 33B. The outer slots 33A are arranged on the outer periphery of the yoke 31 at predetermined intervals from one another in the circumferential direction around the central axis 50. Each of the outer slots 33A extends in both the axial and radial directions. Each of the outer slots 33A is arranged between two adjacent outer protrusions 32A among the outer protrusions 32A. The inner slots 33B are arranged on the inner periphery of the yoke 31 at predetermined intervals from one another in the circumferential direction around the central axis 50. Each of the inner slots 33B extends in both the axial and radial directions. Each of the inner slots 33B is arranged between two adjacent inner protrusions 32B among the inner protrusions 32B.

[0080] Hereinafter, a portion of the stator 3 will be referred to as a unit 60. The unit 60 includes a portion of the yoke 31, one outer slot 33A among the plurality of outer slots 33A, and one inner slot 33B among the plurality of inner slots 33B. The unit 60 also includes two outer protrusions 32A that sandwich the one outer slot 33A, and two inner protrusions 32B that sandwich the one inner slot 33B. The unit 60 also includes a winding 40 that is wound around the yoke 31 and passes through the pair of outer slots 33A and inner slots 33B. The stator 3 has a plurality of units 60 connected in a ring shape.

[0081] FIG. 16 is a schematic perspective view of an example of winding 40 according to the second embodiment of the present disclosure.

[0082] The winding 40 includes a plurality of segment conductors 41 stacked in the circumferential direction. In the rotating electric machine 1, the stacking direction indicates the circumferential direction. The winding 40 passes through a pair of outer slots 33A and inner slots 33B and is wound around the yoke 31 located between the two protrusions 32 (the outer protrusion 32A and the inner protrusion 32B) so as to extend in the axial and radial directions. The winding 40 is also wound around a pair of outer slots 33A and inner slots 33B adjacent to the yoke 31.

[0083] The second segment conductor portion 42 refers to a portion of the segment conductor 41 that is arranged in a pair of opposing outer slots 33A and inner slots 33B among the plurality of outer slots 33A and inner slots 33B. One of the second segment conductor portions 42 of the segment conductor 41 is housed in the outer slot 33A, and the other of the second segment conductor portion 42 of the segment conductor is housed in the inner slot 33B. The first segment conductor portion 43 refers to a portion of the segment conductor 41 that is arranged in a coil end portion that protrudes in the axial direction from the axial end surface 36 of the stator core 30. In the second embodiment, each segment conductor 41 of the winding 40 included in the unit 60 has two second segment conductor portions 42 located at both radial ends of the yoke 31 and two first segment conductor portions 43 located at both axial ends of the yoke 31.

[0084] Fig. 17 is a schematic perspective view showing an example of a unit 60 of a stator 3 according to embodiment 2. As shown in Fig. 17, a pair of second segment conductor portions 42 are arranged in opposing outer slots 33A and inner slots 33B located at both radial ends of the yoke 31. The first segment conductor portion 43 protrudes from the axial end face 36 of the yoke 31. In Fig. 17, the winding 40 is wound around the yoke 31. The winding 40 is also wound in the pair of outer slots 33A and inner slots 33B.

[0085] The winding 40 may be configured such that the first segment conductor portions 43 are bent in the stacking direction, i.e., the circumferential direction. One of the circumferential directions is an example of a first direction. The other of the circumferential directions is an example of a second direction. For example, a first group of first segment conductor portions 43, which are some of the first segment conductor portions 43, may be bent in the circumferential direction toward one of the two protrusions 32 that sandwich the outer slot 33A and the inner slot 33B. Alternatively, a second group of first segment conductor portions 43, which are some of the first segment conductor portions 43 other than the first group of first segment conductor portions 43, may be bent in the circumferential direction toward the other of the two protrusions 32. Alternatively, the winding 40 may be configured such that at least some of the first segment conductor portions 43 are bent in the circumferential direction toward only one of the two protrusions 32 that sandwich the outer slot 33A and the inner slot 33B.

[0086] Furthermore, the first segment conductor portion 43 of each segment conductor 41 may be configured so that its thickness varies in at least one of the axial and circumferential directions. The thickness of the first segment conductor portion 43 may be defined as the minimum value of the dimensions in a direction perpendicular to the radial direction of the segment conductor 41 located at the coil end portion, at a cut end surface of the segment conductor 41 cut along an imaginary plane parallel to the imaginary plane formed by the axial direction and the stacking direction. Hereinafter, in the second embodiment, an imaginary plane parallel to the imaginary plane formed by the circumferential direction, which is the stacking direction, and the axial direction is also referred to as a "first plane." The first plane may refer to an imaginary plane parallel to the imaginary plane formed in the axial direction and tangential to the central axis 50 of each segment conductor 41.

[0087] By configuring in this manner, the stator 3 in which the winding 40 is wound in a toroidal winding can be formed so that the length of the first segment conductor portion 43 is short, just like the stator 3 in which the winding 40 is wound in a concentrated winding.

[0088] [Effects] The stator 3 according to the second embodiment of the present disclosure can provide the following effects.

[0089] The stator 3 includes an annular stator core 30 surrounding a central axis 50 and a plurality of windings 40. The stator core 30 has a plurality of slots 33 arranged circumferentially around the central axis 50 at predetermined intervals and extending in an axial direction parallel to the central axis 50 and in a radial direction. The plurality of windings 40 includes a plurality of segment conductors 41 stacked in a stacking direction, which is the circumferential direction, and wound around each slot 33. Each segment conductor 41 includes a pair of second segment conductor portions 42 arranged in a pair of opposing slots 33 among the plurality of slots 33, and a first segment conductor portion 43 arranged in a coil end portion protruding in the axial direction from an axial end face 36 of the stator core. The first segment conductor portions 43 of some of the plurality of segment conductors 41 are configured to bend in the stacking direction. A first group of first segment conductor portions 43, which are some of the plurality of first segment conductor portions 43, are configured to bend in a first direction, which is the stacking direction. The first segment conductor portions 43 of the second group, which are some of the first segment conductor portions 43 different from the first group of first segment conductor portions 43, are configured to bend in a second direction opposite to the first direction. The segment conductors 41 are stacked in the circumferential direction. The first direction and the second direction are two opposite directions in the circumferential direction.

[0090] With this configuration, the first segment conductor portions 43 of the first group are bent in a predetermined circumferential direction, and the first segment conductor portions 43 of the second group are bent in the opposite circumferential direction. This reduces the axial protrusion length of the first segment conductor portions 43 compared to when the first segment conductor portions 43 are bent in only one circumferential direction of the stator core 30. This allows the stator 3 to be made smaller.

[0091] Furthermore, in the stator 3, each winding 40 is wound in a toroidal manner. With this configuration, in the stator 3 in which the winding 40 is wound in a toroidal manner, the protruding length of the first segment conductor portion 43 can be shortened. This allows the stator 3 to be made smaller. Furthermore, the rotating electric machine 1 having the stator 3 can be made smaller.

[0092] (Third Embodiment) An overview of a rotating electric machine 1 according to a third embodiment will be described. In the third embodiment, differences from the first embodiment will be mainly described. In the third embodiment, components that are the same as or equivalent to those in the first embodiment will be described with the same reference numerals. Furthermore, in the third embodiment, descriptions that overlap with those in the first embodiment may be omitted.

[0093] As described above, in the first embodiment, in each segment conductor 41 of the winding 40, the cross-sectional area of ​​the second segment conductor portion 42 in the second plane and the cross-sectional area of ​​the first segment conductor portion 43 in the first plane are configured to be substantially equal to each other. In the third embodiment, the rotating electric machine 1 according to the third embodiment differs from the rotating electric machine 1 according to the first embodiment in that the cross-sectional area of ​​the first segment conductor portion 43 in the first plane is configured to be larger than the cross-sectional area of ​​the second segment conductor portion 42 in the second plane. As in the first embodiment, in the third embodiment, the "first plane" refers to an imaginary plane that is parallel to an imaginary plane formed in the radial direction, which is the lamination direction, and in the axial direction.

[0094] FIG. 18 is a schematic perspective view illustrating an example of a unit 60 of a stator 3 according to embodiment 3 of the present disclosure. Only a portion of the unit 60 is shown in FIG. 18 . As with the unit 60 according to embodiment 1, a pair of second segment conductor portions 42 of each segment conductor of the winding 40 in the unit 60 according to embodiment 3 are disposed in a pair of opposing slots 33 located at both circumferential ends of the projection 32. The first segment conductor portions 43 protrude from the axial end surface 36 of the projection 32. As with the unit 60 shown in FIG. 5 , in the unit 60 according to embodiment 3, the first segment conductor portions 43 protrude in the −Z direction from the axial end surface of the projection 32.

[0095] The stator 3 according to the third embodiment has a plurality of units 60 connected in an annular shape.

[0096] Figure 19 is a cross-sectional end view taken along line XIX-XIX of a portion of the unit 60 shown in Figure 18. Figure 19 also shows an end view illustrating a portion of the cut end surface of the unit 60 taken along line XIX-XIX in Figure 18 in a first plane. Figure 19 also shows the cut end surface of the first segment conductor portion 43 and the cut end surfaces of a portion of the projection 32 and the yoke 31. The end view of the unit 60 in the second plane according to the third embodiment is the same as that shown in Figure 6. Dimension D4 indicates the axial dimension between the axial end of the first segment conductor portion 43 that protrudes most axially from the stator core 30 and the axial end face 36 of the stator core 30 in the winding 40 according to the third embodiment.

[0097] As described above, the first segment conductor portion 43 of each segment conductor 41 protrudes in the axial direction from the end face 36 of the stator core 30. In the third embodiment, the winding 40 is formed so that the cross-sectional area of ​​the first segment conductor portion 43 in the first plane is larger than the cross-sectional area of ​​the second segment conductor portion 42 in the second plane. For example, in the third embodiment, the cross-sectional area of ​​the first segment conductor portion 43 in the first plane is twice the cross-sectional area of ​​the second segment conductor portion 42 in the second plane.

[0098] At least some of the first segment conductor portions 43 among the plurality of first segment conductor portions 43 are configured so that the thickness of the first segment conductor portions 43 varies in at least one of the axial direction and the radial direction. Furthermore, in the third embodiment, at least some of the first segment conductor portions 43 are formed so that the thickness of the first segment conductor portions 43 in the first plane is greater than the thickness of the first segment conductor portions 43 in the first embodiment. Furthermore, in the third embodiment, at least some of the first segment conductor portions 43 are formed so that they extend longer in the radial direction or in the direction opposite to the radial direction than the first segment conductor portions 43 in the first embodiment.

[0099] The first segment conductor portions 43 of the first group, which are some of the first segment conductor portions 43, are bent in the radial direction. The first segment conductor portions 43 of the second group, which are some of the first segment conductor portions 43 other than the first group first segment conductor portions 43, are bent in the direction opposite to the radial direction.

[0100] By forming the winding 40 in this manner, the cross-sectional area of ​​the first segment conductor portion 43 in the first plane can be configured to be larger than the cross-sectional area of ​​the second segment conductor portion 42 in the second plane. Furthermore, by forming the winding 40 in this manner, the cross-sectional area of ​​the first segment conductor portion 43 in the first plane can be larger than the cross-sectional area of ​​the first segment conductor portion 43 in the first plane in the comparative example described above, while preventing the dimension D4 from becoming longer. For example, the winding 40 is formed so that the dimension D4 is smaller than the dimension D2 in the comparative example.

[0101] With this configuration, the cross-sectional area of ​​the first segment conductor portion 43 is larger than that of the second segment conductor portion 42, thereby reducing copper loss in the first segment conductor portion 43. Furthermore, compared to the case where the first segment conductor portion 43 is extended in the axial direction as in the unit 60 of the comparative example, the unit 60 can be configured so that the cross-sectional area of ​​the first segment conductor portion 43 is larger than that of the second segment conductor portion 42 without increasing the axial length of the coil end portion. As a result, the temperature rise during operation of the stator 3 configured based on the unit 60 having the first segment conductor portion 43 can be suppressed. Suppressing the temperature rise during operation of the stator 3 may include, for example, reducing the amount of heat generated in components of the stator 3. Suppressing the temperature rise during operation of the stator 3 may also include improving the heat dissipation performance of components of the stator 3.

[0102] Furthermore, in the case of a rotating electric machine 1 in which the rotor 2 is located radially inside the stator 3, the first segment conductor portions 43 located on the outside of the rotor 2 link with magnetic flux from the rotor 2. When the first segment conductor portions 43 are not bent so as to extend in the radial direction or in the direction opposite to the radial direction, as shown in the comparative example, the first segment conductor portions 43 link with a large amount of magnetic flux. In contrast, when the first segment conductor portions 43 are bent so as to extend in the radial direction or in the direction opposite to the radial direction, as described above, the first segment conductor portions 43 link with less magnetic flux than in the comparative example. Therefore, with the stator 3 according to embodiment 3, the eddy currents generated in the first segment conductor portions 43 due to the magnetic flux are smaller than in the stator 3 based on the unit 60 shown in the comparative example, and heat generation in the stator 3 can be suppressed.

[0103] In this way, according to the stator 3 of embodiment 3, heat generation in the rotating electric machine 1 including the stator 3 is suppressed during operation, so that the amount of current flowing through the rotating electric machine 1 can be increased, thereby improving the performance of the rotating electric machine 1.

[0104] (Variation 2) Variation 2 of the unit 60 in Embodiment 3 will be described. Variation 2 will mainly describe the differences from the example shown in Fig. 18. In Variation 2, components that are the same as or equivalent to those in the example shown in Fig. 18 will be denoted by the same reference numerals. Also, in Variation 2, descriptions that overlap with those in the example shown in Fig. 18 may be omitted.

[0105] FIG. 20 is a cross-sectional end view showing a portion of a unit 60 in a second variation of the unit 60 of the stator 3 according to the third embodiment. Similar to the end view shown in FIG. 7 , FIG. 20 illustrates an end view showing a portion of the cut end surface of the unit 60 according to the second variation, cut along a first plane. FIG. 20 also illustrates the cut end surface of the first segment conductor portion 43 and the cut end surfaces of a portion of the projection 32 and the yoke 31. The end surface of the unit 60 in the second plane shown in FIG. 20 is configured similarly to that shown in FIG. 6 . Dimension D5 indicates the axial dimension between the axial end of the first segment conductor portion 43 that protrudes most axially from the stator core 30 and the axial end face 36 of the stator core 30 in the winding 40 according to the second variation.

[0106] As in the example shown in Figure 18, in variant example 2, the winding 40 is formed so that the cross-sectional area of ​​the first segment conductor portion 43 in the first plane is twice the cross-sectional area of ​​the second segment conductor portion 42 in the second plane.

[0107] The winding 40 in Modification 2 is bent only in the radial direction. For example, of the multiple first segment conductor portions 43, a first segment conductor portion 43F located on the outer periphery of the stator core 30 extends in the radial direction. Also, of the multiple first segment conductor portions 43, a first segment conductor portion 43G located on the inner periphery of the stator core 30 does not extend in the opposite direction to the radial direction, but only the axial end portion of the first segment conductor portion 43G extends in the radial direction. Also, some of the multiple first segment conductor portions 43 are configured so that the thickness of the first segment conductor portion 43 changes in at least one of the axial and radial directions.

[0108] In this way, the winding 40 may be configured so that the first segment conductor portions 43 are bent only in the radial direction or only in the direction opposite to the radial direction. With this configuration, even if the dimension between the first segment conductor portions 43 located on the inner periphery side of the stator core 30 and the inner periphery side end face of the stator core 30 is small, the cross-sectional area can be increased while suppressing an increase in the dimension D5. Therefore, even if there are spatial constraints, the cross-sectional area of ​​the stator 3 can be increased while suppressing an increase in the axial protrusion length of the first segment conductor portions 43.

[0109] (Variation 3) Variation 3 of the unit 60 in Embodiment 3 will be described. Variation 3 will mainly describe the differences from the example shown in Fig. 18. In Variation 3, components that are the same as or equivalent to those in the example shown in Fig. 18 will be denoted by the same reference numerals. Also, in Variation 3, descriptions that overlap with those in the example shown in Fig. 18 may be omitted.

[0110] Fig. 21 is a cross-sectional end view showing a portion of a unit 60 in Modification 3 of the unit 60 of the stator 3 according to Embodiment 3. Fig. 21 shows an end view showing a portion of the cut end surface of the unit 60 according to Modification 3, cut along a first plane similar to the end view shown in Fig. 7. Fig. 21 also shows the cut end surface of the first segment conductor portion 43 and the cut end surfaces of a portion of the projection 32 and the yoke 31. The end surface of the unit 60 shown in Fig. 21 in the second plane is configured similarly to that shown in Fig. 6.

[0111] In the third modification, the winding 40 is configured so that the cross-sectional area of ​​the first segment conductor portion 43 in the first plane is even larger than the cross-sectional area of ​​the first segment conductor portion 43 in the example shown in Fig. 18. For example, in the third modification, the cross-sectional area of ​​the first segment conductor portion 43 in the first plane is four times the cross-sectional area of ​​the second segment conductor portion 42 in the second plane.

[0112] With this configuration, copper loss in the first segment conductor portion 43 can be further reduced compared to Modification 2, and temperature rise in the stator 3 can be suppressed. For example, heat generation in the first segment conductor portion 43 during operation of the rotating electric machine 1 can be suppressed compared to Modification 2. Therefore, heat generation in the rotating electric machine 1 during operation of the rotating electric machine 1 is suppressed, and the amount of current flowing through the rotating electric machine 1 can be increased, thereby improving the performance of the rotating electric machine 1.

[0113] (Variation 4) Variation 4 of the unit 60 in Embodiment 3 will be described. Variation 4 will mainly describe the differences from the example shown in Fig. 18. In Variation 4, components that are the same as or equivalent to those in the example shown in Fig. 18 will be denoted by the same reference numerals. Also, in Variation 4, descriptions that overlap with those in the example shown in Fig. 18 may be omitted.

[0114] Fig. 22 is a cross-sectional end view showing a portion of the unit 60 in Modification 4 of the unit 60 of the stator 3 according to Embodiment 3. Fig. 22 shows an end view showing a portion of the cut end surface of the unit 60 according to Modification 4, cut along the first plane similar to the end view shown in Fig. 7. Fig. 22 shows the cut end surface of the first segment conductor portion 43 and the cut end surfaces of a portion of the projection 32 and the yoke 31. The end surface of the unit 60 shown in Fig. 22 in the second plane is configured similarly to Fig. 6.

[0115] In the fourth modification, the winding 40 is formed so that the cross-sectional area of ​​the first segment conductor portion 43 in the first plane is larger than the cross-sectional area of ​​the second segment conductor portion 42 in the second plane. The winding 40 is also formed so that the cross-sectional area of ​​the first segment inner conductor portions 43H, 43I closer to the central axis 50 is larger than the cross-sectional area of ​​the first segment outer conductor portions 43J, 43K further from the central axis 50 in the first plane. The first segment inner conductor portions 43H, 43I are examples of first segment conductor portions 43 that are located radially inward and closer to the central axis 50 among the multiple first segment conductor portions 43. The first segment outer conductor portions 43J, 43K are examples of first segment conductor portions 43 that are located radially outward and farther from the central axis 50 among the multiple first segment conductor portions 43. For example, in Modification 4, the cross-sectional area of ​​the first-segment inner conductor portions 43H, 43I in the first plane is four times the cross-sectional area of ​​the second-segment conductor portion 42 in the second plane. The cross-sectional area of ​​the first-segment outer conductor portions 43J, 43K in the first plane is twice the cross-sectional area of ​​the second-segment conductor portion 42 in the second plane. The first-segment outer conductor portions 43J, 43K are an example of a first-group first-segment conductor portion 43. The first-segment inner conductor portions 43H, 43I are an example of a second-group first-segment conductor portion 43.

[0116] In a rotating electric machine 1 in which the rotor 2 is located radially inside the stator 3, the first segment inner conductor portions 43H, 43I are interlinked with more magnetic flux from the rotor 2 than the first segment outer conductor portions 43J, 43K. Therefore, the first segment inner conductor portions 43H, 43I are more likely to generate heat and increase in temperature than the first segment outer conductor portions 43J, 43K. Furthermore, the housing of the rotating electric machine 1 is located farther from the central axis 50 than the first segment outer conductor portions 43J, 43K. Heat generated in the first segment conductor portions 43 can be dissipated from the housing. In this respect, too, the first segment inner conductor portions 43H, 43I are more likely to increase in temperature than the first segment outer conductor portions 43J, 43K.

[0117] In the unit 60 according to the fourth modification, the first cross-sectional areas of the first segment inner conductor portions 43H, 43I are larger than the first cross-sectional areas of the first segment outer conductor portions 43J, 43K. Therefore, the first segment inner conductor portions 43H, 43I have improved heat dissipation performance compared to the first segment outer conductor portions 43J, 43K.

[0118] With this configuration, it is possible to suppress an increase in the axial protrusion length of the first segment conductor portion 43 compared to the unit 60 shown in Modification 3, while suppressing a temperature rise in the coil end portion compared to the unit 60 shown in Fig. 18. Furthermore, it is possible to effectively suppress a temperature rise in the stator 3 including the unit 60. Therefore, heat generation in the rotating electric machine 1 during operation is suppressed, and the amount of current flowing through the rotating electric machine 1 can be increased, thereby improving the performance of the rotating electric machine 1.

[0119] In the third embodiment, the first cross-sectional area is configured to be two or four times the second cross-sectional area, but the ratio of the cross-sectional areas is not limited to two or four. The first cross-sectional area may be configured to be larger than the second cross-sectional area. For example, the first cross-sectional area may be configured to be 1.1, 1.2, 1.5, 2.0, 2.1, 3.0, 4.0, or 5.0 times the second cross-sectional area.

[0120] In the third embodiment, the first cross-sectional area of ​​the inner first segment conductor portion 43 is configured to be substantially equal to or twice the first cross-sectional area of ​​the outer first segment conductor portion 43, but the ratio of the cross-sectional areas is not limited to the above. The first cross-sectional areas of the inner first segment conductor portion 43 and the outer first segment conductor portion 43 may be configured to be different from each other. The first cross-sectional area of ​​the inner first segment conductor portion 43 may be configured to be equal to or greater than the first cross-sectional area of ​​the outer first segment conductor portion 43. For example, the first cross-sectional area of ​​the inner first segment conductor portion 43 may be configured to be 1.1 times, 1.2 times, 1.5 times, 2.0 times, 2.1 times, 3.0 times, 4.0 times, or 5.0 times the first cross-sectional area of ​​the outer first segment conductor portion 43. Alternatively, the first cross-sectional area of ​​the first conductor segment 43 arranged on the outside may be equal to or greater than the first cross-sectional area of ​​the first conductor segment 43 arranged on the inside.

[0121] In the third embodiment described above, the winding 40 is wound around the projections 32 of the stator core 30 by concentrated winding, but the winding method of the winding 40 is not limited to concentrated winding. As in the example shown in the second embodiment, the winding 40 may also be wound around the projections 32 by toroidal winding in the unit 60 shown in the third embodiment.

[0122] [Effects] The stator 3 according to the third embodiment of the present disclosure can provide the following effects.

[0123] The stator 3 includes an annular stator core 30 surrounding a central axis 50 and a plurality of windings 40. The stator core 30 has a plurality of slots 33 arranged at predetermined intervals circumferentially around the central axis 50 and extending in an axial direction and a radial direction parallel to the central axis 50. The plurality of windings 40 includes a plurality of segment conductors 41 stacked in a lamination direction, which is the radial or circumferential direction, and wound around each slot 33. Each segment conductor 41 includes a first segment conductor portion 43 arranged in a coil end portion that protrudes in the axial direction from an axial end face 36 of the stator core, and a pair of second segment conductor portions 42 arranged in a pair of opposing slots 33 among the plurality of slots 33. The first cross-sectional area of ​​the first segment conductor portion 43 of each of the plurality of segment conductors 41 in a first plane parallel to a plane formed in the lamination direction and the axial direction is larger than the second cross-sectional area of ​​the second segment conductor portion 42 of each of the plurality of segment conductors 41 in a second plane perpendicular to the axial direction.

[0124] With this configuration, the cross-sectional area of ​​the first segment conductor portion 43 is larger than the cross-sectional area of ​​the second segment conductor portion 42, and copper loss in the first segment conductor portion 43 can be reduced compared to copper loss in the second segment conductor portion 42. Reducing copper loss in the first segment conductor portion 43 can suppress heat generation in the first segment conductor portion 43. Therefore, temperature rise in the stator 3 configured based on the unit 60 including the first segment conductor portion 43 can be suppressed.

[0125] Furthermore, in the stator 3, the first segment conductor portions 43 of some of the segment conductors 41 are configured to bend in the stacking direction. This configuration makes it possible to shorten the axial protrusion length of the first segment conductor portions 43 arranged at the coil end portions of the windings 40 in the stator 3. In other words, the height of the first segment conductor portions 43 can be made lower than when the first segment conductor portions 43 are not bent. This allows the stator 3 to be made smaller while suppressing temperature increases in the stator 3.

[0126] Furthermore, in the stator 3, the first cross-sectional areas of the first group of first segment conductor portions 43, which are some of the multiple first segment conductor portions 43, are different in size from the first cross-sectional areas of the second group of first segment conductor portions 43, which are some of the first segment conductor portions 43 different from the first group of first segment conductor portions 43. This configuration can reduce copper loss in some of the first segment conductor portions 43 of the multiple first segment conductor portions 43. Therefore, by selectively increasing the first cross-sectional areas of the first segment conductor portions 43 that generate more heat than the other first segment conductor portions 43, the temperature rise of the stator 3 can be suppressed.

[0127] Furthermore, in the stator 3, each winding 40 is formed by additive manufacturing. By forming the winding 40 by additive manufacturing, the thickness of the first segment conductor portion 43 of each segment conductor 41 can be configured to change in at least one of the axial and radial directions. Therefore, the first cross-sectional area can be made larger than the second cross-sectional area, and temperature rise in the stator 3 can be suppressed.

[0128] In the stator 3, the plurality of segment conductors 41 are stacked in the radial direction. The plurality of first segment conductor portions 43 include a first segment inner conductor portion 43H disposed radially inward and closer to the central axis 50, and a first segment outer conductor portion 43K disposed radially outward and farther from the central axis 50 than the first segment inner conductor portion 43H. The first cross-sectional area of ​​the first segment inner conductor portion 43H is configured to be equal to or greater than the first cross-sectional area of ​​the first segment outer conductor portion 43K.

[0129] Of the multiple first segment conductor portions 43, the first segment inner conductor portion 43H, which is closer to the central axis 50, may generate more heat than the first segment outer conductor portion 43K, which is farther from the central axis 50 than the first segment inner conductor portion 43H. For example, the first segment inner conductor portion 43H may generate more heat due to eddy currents generated by magnetic flux from the rotor 2 during operation of the rotating electric machine 1 than the first segment outer conductor portion 43K. With the above configuration, the first cross-sectional area of ​​the first segment inner conductor portion 43H is larger than the first cross-sectional area of ​​the first segment outer conductor portion 43K. As a result, the temperature rise of the first segment inner conductor portion 43H, which may generate a large amount of heat, is suppressed, thereby efficiently suppressing the temperature rise of the stator 3.

[0130] Furthermore, in the stator 3, each winding 40 is wound in concentrated winding. In this way, in the stator 3 in which the winding 40 is wound around the stator core 30 in concentrated winding, the first cross-sectional area of ​​the first segment conductor portion 43 can be made larger than the second cross-sectional area of ​​the second segment conductor portion 42. Therefore, the temperature rise of the stator 3 configured based on the unit 60 including the first segment conductor portion 43 can be suppressed.

[0131] Furthermore, in the stator 3, the segment conductors 41 are stacked in the circumferential direction. Each winding 40 is wound in a toroidal manner. In this way, in the stator 3 in which the winding 40 is wound in a toroidal manner around the stator core 30, the first cross-sectional area of ​​the first segment conductor portion 43 can be made larger than the second cross-sectional area of ​​the second segment conductor portion 42. Therefore, the temperature rise of the stator 3 configured based on the unit 60 including the first segment conductor portion 43 can be suppressed.

[0132] The rotating electric machine 1 includes a housing 4, the above-mentioned stator 3, and a rotor 2 arranged on at least one of the radially inner side and the radially outer side of the stator 3 with a first gap therebetween and rotatable about a central axis 50. The stator 3 and the rotor 2 are accommodated in the housing 4. The stator 3 is configured such that the first cross-sectional area of ​​the first segment conductor portion 43 is larger than the second cross-sectional area of ​​the second segment conductor portion 42, so that a temperature rise in the rotating electric machine 1 can be suppressed.

[0133] (Fourth Embodiment) An overview of a rotating electric machine 1 according to a fourth embodiment will be described. In the fourth embodiment, differences from the third embodiment will be mainly described. In the fourth embodiment, components that are the same as or equivalent to those in the third embodiment will be described with the same reference numerals. Furthermore, in the fourth embodiment, descriptions that overlap with those in the third embodiment may be omitted.

[0134] 18 , in the third embodiment, the radially inner ends of some of the first segment conductor portions 43 are configured to be straight. Furthermore, the radially outer ends of some of the first segment conductor portions 43 are configured to be straight. In the fourth embodiment, the rotating electric machine 1 according to the fourth embodiment differs from the rotating electric machine 1 according to the third embodiment in that the ends of at least some of the first segment conductor portions 43 are configured to have a curvature that follows the inner or outer periphery of the stator core 30. As in the first embodiment, in the fourth embodiment, the "first plane" refers to an imaginary plane that is parallel to an imaginary plane formed in the radial direction, which is the lamination direction, and in the axial direction.

[0135] FIG. 23 is a schematic perspective view illustrating an example of a unit 60 of a stator 3 according to embodiment 4 of the present disclosure. Only a portion of the unit 60 is shown in FIG. 23 . As with the unit 60 according to embodiment 3, a pair of second segment conductor portions 42 of each segment conductor of the winding 40 in the unit 60 according to embodiment 4 are disposed in a pair of opposing slots 33 located at both circumferential ends of the projection 32. The first segment conductor portions 43 protrude from the axial end surface 36 of the projection 32. As with the unit 60 shown in FIG. 5 , in the unit 60 according to embodiment 4, the first segment conductor portions 43 protrude in the −Z direction from the axial end surface of the projection 32.

[0136] Similar to the third embodiment, the stator 3 according to the fourth embodiment has a plurality of units 60 connected in an annular shape.

[0137] Some of the first segment conductor portions 43 are located radially inward and have end portions 45 that have a curvature that follows the inner circumference of the stator core 30. Some of the first segment conductor portions 43 are located radially outward and have end portions 46 that have a curvature that follows the outer circumference of the stator core 30.

[0138] According to this configuration, the winding 40 is formed so that the cross-sectional area of ​​the first segment conductor portion 43 in the first plane is large. Compared to a stator 3 having a winding 40 configured so that the ends 45, 46 are straight, the stator 3 having the winding 40 according to the fourth embodiment has improved heat dissipation performance. Therefore, heat generation in the rotating electric machine 1 during operation is suppressed, and the amount of current flowing through the rotating electric machine 1 can be increased, thereby improving the performance of the rotating electric machine 1.

[0139] Figure 24 is a cross-sectional end view taken along line XXIV-XXIV of a portion of the unit 60 shown in Figure 23. Figure 24 shows an end view illustrating a portion of the cut end surface of the unit 60 cut along line XXIV-XXIV in Figure 23 on a first plane. Figure 24 also shows the cut end surface of the first segment conductor portion 43 and the cut end surfaces of a portion of the projection 32 and the yoke 31. The end view of the unit 60 according to embodiment 4 on the second plane is the same as Figure 6.

[0140] As shown in FIG. 24 , the first segment conductor portion 43L is formed to extend in a direction toward the central axis 50. In other words, the first segment conductor portion 43L is formed to bend in a direction opposite to the radial direction. The first segment conductor portion 43M is formed to extend in a direction away from the stator core 30 along the axial direction, and the axial end portion of the first segment conductor portion 43M is formed to extend both in the radial direction and in the direction opposite to the radial direction. In other words, the first segment conductor portion 43M is formed to bend in the radial direction and in the direction opposite to the radial direction. The first segment conductor portion 43N is formed to extend in a direction away from the central axis 50, and the radially outer end portion of the first segment conductor portion 43N is formed to extend in a direction away from the stator core 30 in the axial direction. In other words, the first segment conductor portion 43N is formed to bend in the radial direction and also bend in the axial direction away from the stator core 30.

[0141] With this configuration, the cross-sectional area of ​​each first segment conductor portion 43 in the first plane is larger than the cross-sectional area of ​​each first segment conductor portion 43 in the example shown in FIG. 5 , for example, and copper loss in the first segment conductor portion 43 can be reduced. Furthermore, the axial protrusion length of the first segment conductor portion 43 can be shorter than when the first segment conductor portion 43 extends only in the axial direction. As a result, the stator 3 configured based on the unit 60 including the first segment conductor portion 43 can be prevented from increasing in size while also suppressing temperature increases in the stator 3. Therefore, heat generation in the rotating electric machine 1 during operation is suppressed, allowing the amount of current flowing through the rotating electric machine 1 to be increased, thereby improving the performance of the rotating electric machine 1.

[0142] (Modification 5) Modification 5 of the unit 60 in Embodiment 4 will be described. Modification 5 will mainly describe the differences from the example shown in Fig. 24. In Modification 5, components that are the same as or equivalent to those in the example shown in Fig. 24 will be denoted with the same reference numerals. Also, in Modification 5, descriptions that overlap with those in the example shown in Fig. 24 may be omitted.

[0143] Fig. 25 is a cross-sectional end view showing a portion of the unit 60 in Modification 5 of the unit 60 of the stator 3 according to Embodiment 4. Fig. 25 shows an end view showing a portion of the cut end surface of the unit 60 according to Modification 5, cut along the first plane like the end view shown in Fig. 24 . Fig. 25 also shows the cut end surface of the first segment conductor portion 43 and the cut end surfaces of a portion of the projection 32 and the yoke 31. The end surface of the unit 60 shown in Fig. 25 in the second plane is configured similarly to Fig. 6 .

[0144] 25, the first segment conductor portion 43P is formed so as to extend in a direction away from the central axis 50. In other words, the first segment conductor portion 43P is formed so as to bend in the radial direction.

[0145] 25 , this configuration can suppress an increase in temperature of the stator 3 while suppressing an increase in size of the stator 3 configured based on the unit 60 having the first segment conductor portion 43. Therefore, heat generation by the rotating electric machine 1 during operation is suppressed, and the amount of current flowing through the rotating electric machine 1 can be increased, thereby improving the performance of the rotating electric machine 1.

[0146] Example 1 A first example of a rotating electric machine 1 using Modification 5 of the unit 60 in Embodiment 4 will be described. FIG. 26 is a cross-sectional end view showing a portion of the rotating electric machine 1 using Modification 5. In addition to the end face shown in FIG. 24 , FIG. 26 also shows an end face of a portion of the housing 4 of the rotating electric machine 1 in a first plane. As described above, the housing 4 accommodates the rotor 2 and the stator 3. The first segment conductor portion 43 includes an axial end 47 that is a portion axially distant from the stator core 30, and a radial end 46 that is a portion radially distant from the central axis 50. At least one of the end 46 and the end 47 is an example of a predetermined end.

[0147] 25 , the rotating electric machine 1 has a predetermined gap Da between the axial end 47 of the first segment conductor portion 43 and the inner surface of the housing 4. The rotating electric machine 1 also has a predetermined gap Db between the radial end 46 of the first segment conductor portion 43 and the inner surface of the housing 4. The predetermined gap Da and the predetermined gap Db are examples of a second gap.

[0148] In the unit 60 shown in Modification 5, the axial end 47 of the first segment conductor portion 43 is configured to extend along an imaginary plane perpendicular to the axial direction, with a predetermined gap Da between the end 47 and the inner surface of the housing 4. In other words, the axial end 47 of the first segment conductor portion 43 is formed flat so as to fit along the housing 4. Furthermore, the radial end 46 of the first segment conductor portion 43 is configured to extend along the inner surface of the housing 4, with a predetermined gap Db between the end 46 and the inner surface of the housing 4.

[0149] With this configuration, the end of the first segment conductor portion 43 is disposed close to the housing 4, and heat from the first segment conductor portion 43 is effectively transferred to the housing 4. Therefore, the rotating electric machine 1 of Example 1 has improved heat dissipation performance compared to a rotating electric machine not configured as described above. Therefore, the temperature rise of the rotating electric machine 1 during operation is suppressed, and the amount of current flowing through the rotating electric machine 1 can be increased, thereby improving the performance of the rotating electric machine 1.

[0150] 26, the stator core 30 is positioned with a predetermined gap from the housing 4 in the first plane, but the position of the stator core 30 is not limited to this. For example, the stator core 30 may be disposed in the housing 4 in contact with the inner surface of the housing 4 without a predetermined gap.

[0151] In the first embodiment, the first segment conductor portion 43 has the end portions 47, 46 that have the predetermined gaps Da, Db with the inner surface of the housing 4, but the first segment conductor portion 43 is not limited to this configuration. For example, the first segment conductor portion 43 may have only the end portion 47 that has the predetermined gap Da with the inner surface of the housing 4. Alternatively, the first segment conductor portion 43 may have only the end portion 46 that has the predetermined gap Db with the inner surface of the housing 4.

[0152] (Example 2) Example 2 of the rotating electric machine 1, which is different from Example 1, will be described. In Example 2, differences from the example shown in FIG. 26 will be mainly described. In Example 2, components that are the same as or equivalent to those in the example shown in FIG. 26 will be described using the same reference numerals. Furthermore, in Example 2, descriptions that overlap with those in the example shown in FIG. 26 may be omitted.

[0153] Fig. 27 is a cross-sectional end view showing a portion of the rotating electric machine 1 using Modification 5. The rotating electric machine 1 shown in Fig. 27 further includes a heat dissipation sheet 80. Fig. 27 shows a partial end face of the heat dissipation sheet 80 in addition to the end face shown in Fig. 26. The heat dissipation sheet 80 is a sheet having a thermal conductivity higher than at least air. The heat dissipation sheet 80 may be, for example, a silicon-based heat dissipation sheet.

[0154] 27 , in Example 2, the heat dissipation sheet 80 is arranged so as to cover the first segment conductor portion 43. The heat dissipation sheet 80 is also arranged at the predetermined gap Da and the predetermined gap Db. In Example 2, the heat dissipation sheet 80 is arranged so as to cover the first segment conductor portion 43, but the position of the heat dissipation sheet 80 is not limited to this. For example, the heat dissipation sheet 80 may be arranged at least one of the predetermined gap Da and the predetermined gap Db.

[0155] With this configuration, heat from the first segment conductor portion 43 is effectively transferred to the housing 4 via the heat dissipation sheet 80. Therefore, the rotating electric machine 1 of Example 2 has improved heat dissipation performance compared to the rotating electric machine 1 of Example 1. Therefore, since the temperature rise of the rotating electric machine 1 during operation is suppressed, the amount of current flowing through the rotating electric machine 1 can be increased, and the performance of the rotating electric machine 1 can be improved.

[0156] (Example 3) Example 3 of the rotating electric machine 1, which is different from Examples 1 and 2, will be described. In Example 3, differences from the example shown in FIG. 26 will be mainly described. In Example 3, components that are the same as or equivalent to those in the example shown in FIG. 26 will be described using the same reference numerals. Furthermore, in Example 3, descriptions that overlap with those in the example shown in FIG. 26 may be omitted.

[0157] Fig. 28 is a cross-sectional end view showing a portion of the rotating electric machine 1 using Modification 5. The rotating electric machine 1 shown in Fig. 28 further includes a resin 81. Fig. 27 shows a partial end face of the resin 81 in addition to the end face shown in Fig. 26. The resin 81 is a material having a thermal conductivity higher than at least air. The resin 81 may be, for example, an epoxy resin.

[0158] As shown in FIG. 28 , in Example 3, the resin 81 is arranged so as to cover the first segment conductor portions 43. The resin 81 is also arranged at the predetermined gaps Da and Db. The resin 81 is arranged so as to fill the gaps between the multiple first segment conductor portions 43. For example, the resin 81 may be filled in the gaps between the multiple first segment conductor portions 43. The arrangement of the resin 81 is not limited to the above. For example, the resin 81 may be arranged in at least one of the gaps between the multiple first segment conductor portions 43, the predetermined gap Da, and the predetermined gap Db.

[0159] With this configuration, heat from the first segment conductor portion 43 is effectively transferred to the housing 4 via the resin 81. Therefore, the rotating electric machine 1 in Example 3 has improved heat dissipation performance compared to the rotating electric machine 1 in Example 1 or Example 2. Therefore, the temperature rise of the rotating electric machine 1 during operation is suppressed, so that the amount of current flowing through the rotating electric machine 1 can be increased, thereby improving the performance of the rotating electric machine 1.

[0160] The rotating electric machines 1 according to the above-described multiple examples include the unit 60 of Modification 1 shown in Fig. 25, but the configuration of the rotating electric machine 1 is not limited to this. For example, the rotating electric machines 1 according to the above-described examples may include the unit 60 of the example shown in Fig. 24. Furthermore, the configuration of the example may be applied to the unit 60 of the example shown in Embodiments 1 to 3.

[0161] In the above-described third and fourth embodiments, the windings 40 are wound around the projections 32 of the stator core 30 by concentrated winding, but the winding method of the windings 40 is not limited to concentrated winding. As in the example shown in the second embodiment, the windings 40 may also be wound around the projections 32 by toroidal winding in the units 60 shown in the third and fourth embodiments.

[0162] [Effects] The stator 3 according to the fourth embodiment of the present disclosure can provide the following effects.

[0163] The stator 3 includes an annular stator core 30 surrounding a central axis 50 and a plurality of windings 40. The stator core 30 has a plurality of slots 33 arranged at predetermined intervals circumferentially around the central axis 50 and extending in an axial direction parallel to the central axis 50 and in a radial direction. The plurality of windings 40 includes a plurality of segment conductors 41 stacked in a lamination direction, which is the radial direction, and wound around each slot 33. Each segment conductor 41 includes a first segment conductor portion 43 disposed in a coil end portion that protrudes in the axial direction from an axial end face 36 of the stator core, and a pair of second segment conductor portions 42 disposed in a pair of opposing slots 33 among the plurality of slots 33. The first cross-sectional area of ​​the first segment conductor portion 43 of each of the plurality of segment conductors 41 in a first plane parallel to a plane formed in the lamination direction and the axial direction is larger than the second cross-sectional area of ​​the second segment conductor portion 42 of each of the plurality of segment conductors 41 in a second plane perpendicular to the axial direction.

[0164] The plurality of segment conductors 41 are stacked in the radial direction. At least some of the plurality of first segment conductor portions 43 include at least one of an end portion 45 located in the radial direction and having a curvature that follows the inner periphery of the stator core 30, and an end portion 46 located in the opposite radial direction and having a curvature that follows the outer periphery of the stator core 30.

[0165] With this configuration, the first cross-sectional area of ​​the first segment conductor portion 43 can be increased compared to a configuration in which the first segment conductor portion 43 does not have a curvature along the inner or outer circumference of the stator core 30. Therefore, a temperature rise in the stator 3 formed based on the unit 60 including the first segment conductor portion 43 can be suppressed.

[0166] The rotating electric machine 1 includes a housing 4, the above-mentioned stator 3, and a rotor 2 arranged on at least one of the radially inner side and the radially outer side of the stator 3 with a first gap therebetween and rotatable about a central axis 50. The stator 3 and the rotor 2 are accommodated in the housing 4. The stator 3 is configured such that the first cross-sectional area of ​​the first segment conductor portion 43 is larger than the second cross-sectional area of ​​the second segment conductor portion 42, so that a temperature rise in the rotating electric machine 1 can be suppressed.

[0167] Furthermore, in the rotating electric machine 1, the first segment conductor portion 43 includes a predetermined end portion, which is at least one of the axial end portion 47 and the stacking direction end portion 46, and the predetermined end portion is configured to extend along the inner surface of the housing 4 via a second gap between the predetermined end portion and the inner surface of the housing 4. With this configuration, the first segment conductor portion 43 is disposed close to the housing 4, and heat from the first segment conductor portion 43 is effectively transferred to the housing 4. The rotating electric machine 1 configured as described above has improved heat dissipation performance compared to a rotating electric machine not configured as described above. Therefore, the temperature rise of the rotating electric machine 1 during operation is suppressed, and the amount of current flowing through the rotating electric machine 1 can be increased, thereby improving the performance of the rotating electric machine 1.

[0168] The rotating electric machine 1 further includes a heat dissipation sheet 80 disposed in the second gap. With this configuration, heat from the first segment conductor portion 43 is effectively transferred to the housing 4 via the heat dissipation sheet 80. This suppresses a rise in the temperature of the rotating electric machine 1 during operation, allowing the amount of current flowing through the rotating electric machine 1 to be increased, thereby improving the performance of the rotating electric machine 1.

[0169] The rotating electric machine 1 further includes a resin 81 disposed in the second gap. With this configuration, heat from the first segment conductor portion 43 is effectively transferred to the housing 4 via the resin 81. This suppresses a rise in temperature of the rotating electric machine 1 during operation, allowing the amount of current flowing through the rotating electric machine 1 to be increased, thereby improving the performance of the rotating electric machine 1.

[0170] (Summary of Aspects) As is clear from the above description, the present disclosure includes the following aspects. In the following, reference numerals are given in parentheses only to clarify the correspondence with the embodiments.

[0171] (Aspect 1) A stator (3) according to the present disclosure comprises: an annular stator core (30) surrounding a central axis (50), the stator core having a plurality of slots (33) arranged at predetermined intervals in the circumferential direction around the central axis and extending in an axial direction and a radial direction parallel to the central axis; and a plurality of segment conductors (41) stacked in a stacking direction that is the radial direction or the circumferential direction, and a plurality of windings (40) wound in each of the slots, each of the segment conductors including a first segment conductor portion (43) arranged in a coil end portion that protrudes in the axial direction from an axial end face (36) of the stator core, and a pair of second segment conductor portions (42) arranged in a pair of opposing slots among the plurality of slots, and the first segment conductor portions of some of the plurality of segment conductors are configured to bend in the stacking direction.

[0172] (Aspect 2) In the stator (3) of aspect 1, the first segment conductor portion (43) may be configured so that the thickness of the first segment conductor portion changes in at least one of the axial direction, the radial direction, and the circumferential direction.

[0173] (Aspect 3) In the stator (3) of aspect 1 or aspect 2, the first cross-sectional areas of the first segment conductor portions (43) of the plurality of segment conductors (41), which are in a first plane parallel to a plane formed in the stacking direction and the axial direction, may be substantially equal to each other.

[0174] (Aspect 4) In the stator (3) of Aspects 1 to 3, a first cross-sectional area of ​​the first segment conductor portion (43) of each of the plurality of segment conductors (41), which is in a first plane parallel to a plane formed in the stacking direction and the axial direction, may be substantially equal to a second cross-sectional area of ​​the second segment conductor portion (42) of each of the plurality of segment conductors, which is in a second plane perpendicular to the axial direction.

[0175] (Aspect 5) In the stator (3) of any one of Aspects 1 to 4, a first group of first segment conductor portions, which are some of the multiple first segment conductor portions (43), may be configured to bend in a first direction, which is the stacking direction, and a second group of first segment conductor portions, which are some of the first segment conductor portions different from the first group of first segment conductor portions, may be configured to bend in a second direction opposite to the first direction.

[0176] (Aspect 6) In the stator (3) of aspect 5, the plurality of segment conductors (41) may be stacked in the radial direction, the first direction may be the radial direction, and the second direction may be a direction opposite to the radial direction.

[0177] (Aspect 7) In the stator (3) of aspect 6, each of the windings (40) may be wound in a concentrated winding manner.

[0178] (Aspect 8) In the stator (3) of aspect 5, the plurality of segment conductors (41) may be stacked in the circumferential direction, and the first direction and the second direction may each be two directions in the circumferential direction that are opposite to each other.

[0179] (Aspect 9) In the stator (3) of aspect 8, each of the windings (40) may be wound in a toroidal manner.

[0180] (Aspect 10) In the stator (3) of any one of Aspects 1 to 9, each of the windings (40) may be formed by additive manufacturing.

[0181] (Aspect 11) A rotating electric machine (1) according to the present disclosure comprises: a stator (3) according to any one of aspects 1 to 10; and a rotor (2) arranged at least on either the radially inner side or the radially outer side of the stator via a predetermined gap, and rotatable about the central axis (50).

[0182] As used herein, terms such as "first," "second," etc. are used for descriptive purposes only and should not be understood as expressing or implying relative importance or ranking of technical features. Features qualified as "first" and "second" expressly or imply the inclusion of one or more of that feature.

[0183] Each of the rotating electric machines 1 or stators 3 according to the above-described embodiments may be configured to include at least one of the features described in the other embodiments, unless there is a contradiction.

[0184] According to the present disclosure, it is possible to provide a stator and a rotating electric machine that are smaller in size than those of the prior art, and therefore the present disclosure can be suitably used in this type of industrial field.

[0185] REFERENCE SIGNS LIST 1 Rotating electric machine 2 Rotor 3 Stator 4 Housing 20 Rotor core 30 Stator core 31 Yoke 32 Protrusion 32A Outer protrusion 32B Inner protrusion 33 Slot 33A Outer slot 33B Inner slot 36 End face 40 Winding 41 Segment conductor 42, 42A, 42B Second segment conductor portion 43, 43C, 43D, 43E, 43F, 43G, 43L, 43M, 43N, 43P First segment conductor portion 45 End 46 End 47 End 50 Central shaft 60 Unit 80 Heat dissipation sheet 81 Resin

Claims

1. An annular stator core surrounding a central axis, the stator core having a plurality of slots arranged at predetermined intervals in the circumferential direction around the central axis and extending in the axial direction and the radial direction parallel to the central axis, a plurality of segment conductors laminated in a lamination direction that is either the radial direction or the circumferential direction, and a plurality of windings wound around each slot, each segment conductor including a first segment conductor portion disposed at a coil end portion protruding axially from an axial end face of the stator core, and a pair of second segment conductor portions disposed in a pair of slots facing each other among the plurality of slots, and the first segment conductor portions of some of the plurality of segment conductors being configured to bend in the lamination direction, the stator.

2. The stator according to claim 1, wherein the first segment conductor portion is configured such that the thickness of the first segment conductor portion changes in at least one of the axial direction, the radial direction, and the circumferential direction.

3. The stator according to claim 1, wherein each first cross-sectional area of the first segment conductor portion of each of the plurality of segment conductors, in a first plane parallel to a plane formed in the lamination direction and the axial direction, is substantially equal to each other.

4. The stator according to claim 1, wherein the first cross-sectional area of the first segment conductor portion of each of the plurality of segment conductors, in a first plane parallel to a plane formed in the lamination direction and the axial direction, is substantially equal to the second cross-sectional area of the second segment conductor portion of each of the plurality of segment conductors, in a second plane perpendicular to the axial direction.

5. The stator according to any one of claims 1 to 4, wherein a first group of first segment conductor portions, which are some of the plurality of first segment conductor portions, bend in a first direction that is the lamination direction, and a second group of first segment conductor portions, which are some of the first segment conductor portions different from the first group of first segment conductor portions, are configured to bend in a second direction opposite to the first direction.

6. The plurality of segment conductors are laminated in the radial direction, the first direction is the radial direction, and the second direction is the direction opposite to the radial direction. The stator according to claim 5.

7. Each of the windings is wound in a concentrated winding. The stator according to claim 6.

8. The plurality of segment conductors are laminated in the circumferential direction, and the first direction and the second direction are respectively two opposite directions in the circumferential direction. The stator according to claim 5.

9. Each of the windings is wound in a toroidal winding. The stator according to claim 8.

10. Each of the windings is formed by a laminated manufacturing method. The stator according to claim 1.

11. A rotating electrical machine comprising: the stator according to claim 1; and a rotor disposed with a predetermined gap on at least one of the inner side or the outer side in the radial direction of the stator and rotatable about the central axis.

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