Rotary electric machine

Abstract

To provide a rotary electric machine capable of efficiently transferring heat of a coil to a stator core.SOLUTION: A rotary electric machine includes a stator, a rotor, a housing, and a cover member. The stator has a stator core and a coil. The stator core has a core back portion. The core back portion has an annular shape centered on a central axis. The coil is attached to the stator core. The coil is located radially inside the core back portion. The coil has a coil straight portion and a pair of coil end portions. The coil straight portion extends linearly along the axial direction. The pair of coil end portions protrudes in the axial direction from end faces on both axial sides of the stator core. The cover member has a first cover portion. The first cover portion contacts one of the coil end portions and bends the coil end portion toward the inner peripheral surface of the housing to bring the coil end portion in contact with the inner peripheral surface of the housing.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] An embodiment of the present invention relates to a rotating electric machine. [Background technology]

[0002] In recent years, with the growing awareness of environmental considerations, aircraft in which propulsion fans are driven by rotating electric machines are being developed. Rotating electric machines for aircraft are required to be lightweight. For this reason, it is preferable to adopt an air-cooling type as a cooling mechanism for rotating electric machines for aircraft, and in this case, it is required to efficiently transfer heat from the coil to the stator core. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2017-153230 A Summary of the Invention [Problem to be solved by the invention]

[0004] An object of the present invention is to provide a rotating electric machine capable of efficiently transferring heat from a coil to a stator core. [Means for solving the problem]

[0005] A rotating electric machine according to an embodiment has a stator and a rotor. The stator is annular about a central axis. The rotor is located on one radial side of the stator. The rotor is supported so as to be rotatable about the central axis. The stator has a stator core, a coil, and a resin part. The stator core has a core back part. The core back part is annular about the central axis. The coil is formed by bundling a plurality of coil wires. The coil is disposed on one radial side of the core back part. The resin part fixes the coil to the stator core. The resin part has a first region and a second region. The first region extends in the radial direction along a coil side surface facing the circumferential direction of the coil. The second region extends in the circumferential direction along a support surface facing the one radial side of the core back part. The resin part includes a filler. The thermal conductivity of the first region in the radial direction is greater than the thermal conductivity in the circumferential direction.

[0006] A rotating electric machine according to an embodiment has a stator and a rotor. The stator is annular about a central axis. The rotor is located on one radial side of the stator. The rotor is supported so as to be rotatable about the central axis. The stator has a stator core, a coil, and a resin part. The stator core has a core back part. The core back part is annular about the central axis. The coil is formed by bundling a plurality of coil wires. The coil is disposed on one radial side of the core back part. The resin part fixes the coil to the stator core. The resin part has a first region and a second region. The first region extends radially along a coil side surface facing the circumferential direction of the coil. The second region extends circumferentially along a support surface facing the one radial side of the core back part. The resin part includes a filler. When viewed from the axial direction of the central axis, a first orientation angle is defined as an inclination angle of the length of the filler with respect to the coil side surface. Among the fillers contained in the first region, those having a first orientation angle of less than 45° are more numerous than those having the first orientation angle of 45° or more. [Brief description of the drawings]

[0007] [Figure 1] 1 is a cross-sectional view taken along a central axis of a rotating electric machine according to an embodiment; [Diagram 2]1 is a cross-sectional view perpendicular to a central axis of a rotating electric machine according to an embodiment; [Diagram 3] 1 is a schematic cross-sectional view of a stator included in a rotating electric machine according to an embodiment; [Figure 4] FIG. 4 is an enlarged view of region IV in FIG. [Diagram 5] FIG. 2 is a perspective view showing a schematic diagram of a filler provided in the rotary electric machine according to the embodiment; [Figure 6] 4 is a flowchart of a method for manufacturing a stator included in a rotating electric machine according to an embodiment. [Figure 7] 5 is a schematic diagram showing a jig removal step in the manufacturing method of the stator included in the rotating electric machine according to the embodiment; FIG. [Figure 8] 5 is a schematic diagram showing a resin adding step in the method for manufacturing the stator included in the rotating electric machine according to the embodiment; FIG. [Figure 9] FIG. 11 is a schematic diagram showing a resin part according to a first modified example. [Figure 10] FIG. 11 is a schematic diagram showing a resin part according to a second modified example. [Figure 11] FIG. 1 is a schematic diagram showing an example configuration of an aircraft. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] Hereinafter, a rotating electric machine according to an embodiment will be described with reference to the drawings. The design of a rotating electric machine can be changed as appropriate according to specifications, etc. Therefore, the shape, etc. of each member included in the rotating electric machine can be changed arbitrarily, and the shapes, numbers, etc. in the drawings are merely examples.

[0009] Fig. 1 is a cross-sectional view taken along a central axis J of a rotating electric machine 1 according to this embodiment. Fig. 2 is a cross-sectional view perpendicular to the central axis J of the rotating electric machine 1 according to this embodiment.

[0010] In the following description, the direction parallel to the central axis J is simply referred to as the "axial direction", the radial direction centered on the central axis J is simply referred to as the "radial direction", and the circumferential direction centered on the central axis J is simply referred to as the "circumferential direction θ". In addition, the axial direction AD, the radial direction RD, and the circumferential direction θ are illustrated in each drawing as necessary. In each drawing, the direction in which the arrow of the axial direction AD points is referred to as the "one axial side (+AD)", and the opposite direction is referred to as the "other axial side (-AD)". In addition, the direction in which the arrow of the radial direction RD points is referred to as the "radial inner side" or "one radial side (+RD)", and the opposite direction is referred to as the "radial outer side" or "other radial side (-RD)".

[0011] As shown in FIG. 1, the rotating electric machine 1 includes, for example, an annular stator 30 centered on a central axis J, a rotor 20 positioned radially inside the stator 30, and a cylindrical housing 10 that accommodates the stator 30 and the rotor 20.

[0012] The rotating electric machine 1 of this embodiment is an inner rotor type rotating electric machine in which the rotor 20 is located radially inside the stator 30. However, the rotating electric machine may be an outer rotor type rotating electric machine in which the rotor is located radially outside the stator. In this case, the configuration is such that one radial side and the other radial side are reversed in each part of the rotor.

[0013] The housing 10 has a housing body 12 that extends along the axial direction and surrounds the stator 30 from the radial outside, and bearing holders 11 that are fixed to the ends of the housing body 12 on one and the other axial sides, respectively.

[0014] The housing body 12 has, for example, a cylindrical portion 12a having a cylindrical shape centered on the central axis J, and a plurality of heat dissipation fins 12f protruding radially outward from the outer circumferential surface of the cylindrical portion 12a. The cylindrical portion 12a contacts the stator core 31 of the stator 30 at an inner circumferential surface facing inward in the radial direction. Heat from the stator 30 is transferred to the cylindrical portion 12a and then transferred from the cylindrical portion 12a to the heat dissipation fins 12f. The plurality of heat dissipation fins 12f are arranged, for example, in the circumferential direction with a small gap therebetween. The gaps between the heat dissipation fins 12f open on both sides in the axial direction. The rotating electric machine 1 is mounted on the aircraft 90, for example, in a position in which the central axis J is parallel to the traveling direction of the aircraft 90. As the aircraft 90 flies, air passes through the gaps between the heat dissipation fins 12f, thereby cooling the housing 10.

[0015] The bearing holder 11 is disk-shaped and centered on the central axis J. The pair of bearing holders 11 each cover an opening on both axial sides of the cylindrical portion 12a. The bearing holder 11 has a fixed portion 11a, a tapered portion 11b, and a bearing holding portion 11c. The fixed portion 11a is annular plate-shaped and centered on the central axis J. The fixed portion 11a is fixed to an end face of the cylindrical portion 12a facing the axial direction using a bolt (not shown).

[0016] The tapered portion 11b has, for example, a conical shape. The tapered portion 11b extends from the fixed portion 11a in a radially inward direction and inclined toward the stator 30 in the axial direction AD. The tapered portion 11b is provided with, for example, a plurality of introduction holes 11h. The introduction holes 11h penetrate the tapered portion 11b in the axial direction AD. The plurality of introduction holes 11h communicate the internal space of the housing 10 with the external space. Air from the external space is introduced into the internal space of the housing 10 through, for example, the introduction hole 11h of one bearing holder 11, and cools the rotor 20 and the stator 30. In addition, the air warmed by the rotor 20 and the stator 30 is guided to the outside of the housing 10 through the introduction hole 11h of the other bearing holder 11. The tapered portion 11b is not necessarily provided, and the fixed portion 11a and the bearing holding portion 11c may be connected by a flat surface.

[0017] The bearing holding portion 11c has, for example, a cylindrical shape centered on the central axis J. A bearing B is held on the inner peripheral surface of the bearing holding portion 11c. The bearing B supports the shaft 21 of the rotor 20 so as to be rotatable.

[0018] The rotor 20 is supported by the housing 10 so as to be rotatable about a central axis J. The rotor 20 includes a shaft 21 having a central axis J, a hub member 23, a rotor core 27, a magnet unit 25, and a cover 26.

[0019] The shaft 21 is, for example, columnar and extends in the axial direction about a central axis J. The hub member 23 is, for example, cylindrical and has a sufficient thickness in the radial direction. The hub member 23 is fixed to the outer circumferential surface of the shaft 21. A rotor core 27 is fixed to the outer circumferential surface of the hub member 23. The hub member 23 may be provided with a plurality of through holes 23h that penetrate in the axial direction.

[0020] The rotor core 27 is made of a magnetic material. For example, the rotor core 27 is a laminated steel plate formed by stacking a plurality of electromagnetic steel plates in the axial direction. The rotor core 27 provided in the rotating electric machine 1 according to this embodiment is cylindrical. A magnet unit 25 is disposed on the outer circumferential surface of the rotor core 27.

[0021] 2, the magnet unit 25 has, for example, a circular ring shape. The magnet unit 25 can be fixed to the outer circumferential surface of the rotor core 27 by a joining means such as adhesive. The rotor 20 provided in the rotating electric machine 1 according to this embodiment is a surface magnet type in which the magnet unit 25 directly faces the stator 30 magnetically. The configuration of the rotor 20 is not limited to this embodiment, and may be, for example, an embedded magnet type.

[0022] The magnet unit 25 has magnets 25m with their S poles facing outward in the radial direction and magnets 25m with their N poles facing outward in the radial direction, and these are arranged alternately in the circumferential direction. That is, the magnet unit 25 has a plurality of magnets 25m whose magnetization directions alternate in the circumferential direction. The magnet unit 25 is adhesively fixed to the outer surface of the rotor core 27. The magnet unit 25 is also covered by, for example, a cylindrical cover 26. The cover 26 is made of a material that is unlikely to affect the magnetic force of the magnet unit 25.

[0023] As shown in Fig. 1, the stator 30 surrounds the rotor 20 from the radial outside. As shown in Fig. 2, the stator 30 includes, for example, a stator core 31, a coil 40, a resin part 50, and an insulating member paper (not shown).

[0024] The stator core 31 is, for example, a laminated steel plate formed by stacking a plurality of electromagnetic steel plates in the axial direction. As shown in Fig. 1, the outer peripheral surface of the stator core 31 contacts the inner peripheral surface of the cylindrical portion 12a of the housing 10. Heat from the stator 30 is transferred from the outer peripheral surface of the stator core 31 to the housing 10 and dissipated by the heat dissipation fins 12f.

[0025] 2, the stator core 31 has, for example, a core back portion 32 and a plurality of protruding portions 33. The stator core 31 is made of a magnetic material.

[0026] The core back portion 32 is, for example, annular about the central axis J. The core back portion 32 has a support surface 32a facing radially inward. The coil 40 is disposed on the radially inner side of the core back portion 32. The support surface 32a supports the coil 40 from the radially outer side by sandwiching an insulating member (not shown). The insulating member may be, for example, insulating paper. The insulating member may be any of resin, adhesive, glass cloth, insulating paper, Kapton tape, etc., and may also be other members as long as they are insulating members. This insulating member may be a part of the resin portion 50 described later.

[0027] The multiple protrusions 33 protrude radially inward from the support surface 32a of the core back portion 32. The protrusions 33 have, for example, a rib shape extending along the axial direction. The multiple protrusions 33 are lined up in the circumferential direction. The coil 40 is disposed between the protrusions 33 adjacent to each other in the circumferential direction. That is, the protrusions 33 face the coil 40 in the circumferential direction. The protrusions 33 also have a pair of protrusion side surfaces 33a. One of the pair of protrusion side surfaces 33a faces one circumferential side, and the other faces the other circumferential side.

[0028] The coil 40 is disposed radially inside the core back portion 32 and between the protruding portions 33 arranged in the circumferential direction. The coils 40 are classified into multiple phases. Different phases of AC current flow through the coils 40. The coils 40 included in the rotating electric machine 1 according to the present embodiment include, for example, three phase coils 40, and AC currents with phases shifted by 120° flow through these coils 40. Note that, in order to exemplify and explain a three-phase AC rotating electric machine here, the multiple coils 40 are classified into three phases, but the number of phases is not limited to this embodiment. In addition, the phase difference of the AC current flowing through the coils 40 of each phase is appropriately changed depending on the number of phases. The coils 40 included in the rotating electric machine 1 according to the present embodiment are configured, for example, by distributed winding in which the coils 40 of different phases overlap each other in the radial direction while being shifted in the circumferential direction.

[0029] Fig. 3 is a schematic cross-sectional view of a stator 30 included in the rotary electric machine 1 according to this embodiment. In Fig. 3, the circumferential direction is shown as a straight line.

[0030] As shown in FIG. 3, the coil 40 includes a plurality of wire bundles 42. In the stator 30 of the rotating electric machine 1 according to this embodiment, the wire bundles 42 are arranged in the region between a pair of protruding parts 33. Each wire bundle 42 is formed by bundling a plurality of coil wires 42e. The coil wires 42e may be either round or rectangular, or may have other cross-sectional shapes. The wire bundles 42 are wound in a loop shape between the protruding parts 33 a plurality of times to form the coil 40. Parts of the wire bundles 42 protrude to one and the other axial sides of the stator core 31 to form coil ends 49 (see FIG. 1). The number of wire bundles 42 arranged in the region between the protruding parts 33 can be arbitrarily changed depending on the coil design.

[0031] The coil 40 has a coil side surface 40a. The coil side surface 40a faces in the circumferential direction of the coil. As described above, the coil 40 is formed by bundling a plurality of coil wires 42e, and therefore the coil side surface 40a is formed by connecting the side surfaces of the plurality of coil wires 42e.

[0032] In this embodiment, for example, insulating paper (not shown) is wound around the outer periphery of the coil 40 to ensure insulation between the coil 40 and the stator core 31. The insulating paper may be provided between the coil 40 and the stator core 31, and may be disposed so as to cover the support surface 32a and the protruding portion side surface 33a of the stator core 31.

[0033] The resin portion 50 is provided to fix the coil 40 to the stator core 31. The resin portion 50 is located radially inside the core back portion 32, and is filled in an uncured state between the protruding portions 33 arranged in the circumferential direction, for example, and is cured after the coil 40 is arranged therein.

[0034] 4 is an enlarged view of region IV in FIG. 3. The resin portion 50 includes an adhesive 50b as a binder and a plurality of fillers 50f. The adhesive 50b may be an epoxy resin, a polyester resin, an amide resin, an imide resin, an insulating varnish, or the like. The plurality of fillers 50f are arranged in a diffused manner within the adhesive 50b. Some of the plurality of fillers 50f may be in contact with each other.

[0035] FIG. 5 is a schematic diagram of the filler 50f included in the rotating electric machine 1 according to the present embodiment. The filler 50f is, for example, plate-shaped with a substantially constant thickness t. The thickness t of the filler 50f is, for example, 0.1 μm or more and 200 μm or less. The content of the filler 50f in the resin part 50 can be 10% by weight or more and 90% by weight or less. By blending the filler 50f with the above-mentioned thickness t at a content within the above-mentioned range, the thermal conductivity of the resin part 50 can be increased while ensuring the holding strength of the coil 40 by the resin part 50. Note that the surface of the plate-shaped filler 50f may be uneven. For this reason, the thickness t of the plate-shaped filler 50f is determined by dividing the filler 50f into 10 equal parts in the length direction of the filler 50f, measuring the thickness at each point, and averaging these.

[0036] The filler 50f included in the rotating electric machine 1 according to this embodiment may be ceramics such as aluminum nitride (AlN), silicon nitride (Si3N4), boron nitride (BN), alumina (Al2O3), silica (SiO2), magnesia (MgO), silicon carbide (SiC), or metal nanofibers. In this embodiment, the plate-shaped filler 50f is described, but the filler 50f may have any shape that can define the longitudinal direction. The filler 50f may be amorphous, acicular, or elliptical.

[0037] As shown in FIG. 4, the resin part 50 included in the rotating electric machine 1 according to this embodiment has a first region 51, a second region 52, a third region 53, and a fourth region 54. The first region 51, the second region 52, the third region 53, and the fourth region 54 are each a region in a space surrounded by the support surface 32a of the core back part 32, the protruding part side surface 33a of the protruding part 33, and the coil side surface 40a of the coil 40. The first region 51 is a region extending in the radial direction along the coil side surface 40a. The second region 52 is a region extending in the circumferential direction along the support surface 32a. The third region 53 is a region extending in the radial direction along the protruding part side surface 33a. The fourth region 54 is a region surrounded by the first region 51, the second region 52, and the third region 53. The end of the first region 51 on the radially outer side (-RD) overlaps with the end of the second region 52 on one circumferential side (+RD). Similarly, the end portion of the third region 53 on the radially outer side (-RD) overlaps with the end portion of the second region 52 on the other circumferential side (-RD).

[0038] In the resin part 50 included in the rotating electric machine 1 according to this embodiment, the orientation angles of the filler 50f in the first region 51, the second region 52, and the third region 53 are controlled. The orientation angle of the filler 50f in each region will be specifically described.

[0039] As shown in FIG. 4, the inclination angle of the length direction of the filler 50f with respect to the coil side surface 40a as viewed from the axial direction AD of the central axis J is defined as the first orientation angle α. In this embodiment, it is preferable that the number of fillers 50f included in the first region 51 with the first orientation angle α less than 45° is greater than the number of fillers 50f included in the first region 51 with the first orientation angle α of 45° or more. By setting the first orientation angle α of the filler 50f in the first region 51 to less than 45°, it becomes easier to arrange a wider area of ​​the filler 50f closer to the coil side surface 40a. In particular, as described in FIG. 4, when the filler 50f is plate-shaped, it becomes easier to face the plate surface of the filler 50f toward the coil side surface 40a. For this reason, it becomes easier to transfer heat of the coil 40 to the filler 50f, and it becomes possible to efficiently cool the coil 40.

[0040] In addition, in the first region 51, the filler 50f having a first orientation angle α of less than 45° is likely to be arranged such that the longitudinal direction of the filler 50f is along the radial direction RD. According to this embodiment, the heat transferred from the coil 40 to the resin part 50 in the first region 51 is easily allowed to flow in the radial direction and is difficult to flow in the circumferential direction θ. That is, according to this embodiment, the thermal conductivity of the first region 51 in the radial direction RD is greater than the thermal conductivity in the circumferential direction θ. The core back part 32 is arranged on the radial outer side (-RD) of the first region 51. By increasing the thermal conductivity in the radial direction RD in the first region 51, the heat received by the resin part 50 from the coil 40 can be efficiently transferred to the core back part 32 by flowing it to the radial outer side (-RD). This allows the heat of the coil 40 to be transferred to the core back part 32, thereby efficiently cooling the coil 40.

[0041] In the present embodiment, the case has been described where 50% or more of the fillers 50f in the first region 51 have a first orientation angle α of less than 45°. However, it is more preferable that 60% or more of the fillers 50f in the first region 51 have a first orientation angle α of less than 45°, and it is even more preferable that 70% or more of the fillers 50f in the first region 51 have a first orientation angle α of less than 45°. In this way, by increasing the ratio of the fillers 50f in the first region 51 having a first orientation angle α of less than 45°, the cooling efficiency of the coil 40 can be further improved.

[0042] As described above, the first region 51 is a region along the coil side-face 40a and a region at a certain distance from the coil side-face 40a. When the filler 50f described in FIG. 4 is plate-shaped, the first region 51 is a region in the resin part 50 that is within three times the thickness t of the filler 50f from the coil side-face 40a (d1≦3×t). In the following description, the thickness t of the filler 50f used as a reference for each dimension means the average thickness of the filler 50f included in the resin part 50. When the filler 50f is plate-shaped, the region within three times the thickness t of the filler 50f is a region where the filler 50f is likely to come into contact with the coil side-face 40a and is likely to directly receive heat from the coil side-face 40a. Therefore, by forming the first region 51 in which the filler 50f having the first orientation angle α of less than 45° is dominant within a thickness range of three times the thickness t of the filler 50f, the filler 50f actively receives heat from the coil 40, and the cooling performance of the coil 40 can be effectively improved. In addition, when the filler 50f is plate-shaped, it is easy to control the first orientation angle α of the filler 50f by introducing the uncured resin part 50 into a narrow gap within a range of about three times the thickness t of the filler 50f from the coil side surface 40a. According to this embodiment, it is easy to manufacture the resin part 50 that improves the cooling performance of the coil 40.

[0043] Moreover, the first region 51 is preferably a region within 300 μm (d1≦300 μm) from the coil side surface 40a in the resin part 50. The region within 300 μm from the coil side surface 40a is a region to which heat is easily transferred from the coil side surface 40a. For this reason, by making the first region 51, where the filler 50f having the first orientation angle α of less than 45° is dominant, within a thickness of 300 μm from the coil side surface 40a, the cooling performance of the coil 40 can be effectively improved.

[0044] As shown in FIG. 4, the inclination angle of the filler 50f in the length direction with respect to the support surface 32a of the core back portion 32 as viewed from the axial direction AD of the central axis J is defined as the second orientation angle β. In this embodiment, it is preferable that the number of fillers 50f included in the second region 52 having the second orientation angle β of less than 45° is greater than the number of fillers 50f included in the second region 52 having the second orientation angle β of 45° or more. By setting the second orientation angle β of the filler 50f in the second region 52 to less than 45°, it becomes easier to arrange a wider area of ​​the filler 50f closer to the support surface 32a. Therefore, the heat transferred from the coil 40 to the resin portion is more easily transferred from the resin portion 50 to the core back portion 32, which results in the coil 40 being easier to cool.

[0045] Moreover, in the second region 52, the filler 50f having the second orientation angle β of less than 45° is likely to be arranged such that the longitudinal direction of the filler 50f is aligned with the circumferential direction θ. According to this embodiment, in the second region 52 along the support surface 32a, heat is likely to flow in the circumferential direction θ and is unlikely to flow in the radial direction RD. That is, according to this embodiment, the thermal conductivity of the second region 52 in the circumferential direction θ is greater than the thermal conductivity in the radial direction RD. Therefore, in the second region 52, heat can be dispersed in the circumferential direction of the resin portion 50, and the heat of the resin portion 50 can be transferred to the entire circumferential direction of the core-back portion 32 located on the radial outer side (-RD) of the second region 52. According to this embodiment, heat of the coil 40 is likely to be transferred to the core-back portion 32 via the resin portion 50, and the coil 40 can be efficiently cooled.

[0046] In the present embodiment, the case has been described where 50% or more of the fillers 50f in the second region 52 have a second orientation angle β of less than 45°. However, it is more preferable that 60% or more of the fillers 50f in the second region 52 have a second orientation angle β of less than 45°, and it is even more preferable that 70% or more of the fillers 50f in the second region 52 have a second orientation angle β of less than 45°. In this way, by increasing the ratio of the fillers 50f in the second region 52 having a second orientation angle β of less than 45°, the cooling efficiency of the coil 40 can be further improved.

[0047] As described above, the second region 52 is a region along the support surface 32a and a region at a certain distance from the support surface 32a. When the filler 50f described in FIG. 4 is plate-shaped, the second region 52 is a region in the resin part 50 that is within three times the thickness t of the filler 50f from the support surface 32a (d1≦3×t). When the filler 50f is plate-shaped, the region within three times the thickness t of the filler 50f is a region where the filler 50f is likely to come into contact with the support surface 32a and is likely to directly receive heat from the support surface 32a. For this reason, by including the second region 52 in which the filler 50f with the second orientation angle β of less than 45° is dominant in such a thickness, the filler 50f can actively transfer heat to the core back part 32. Also, when the filler 50f is plate-shaped, it is easy to control the second orientation angle β of the filler 50f if it is within a range of about three times the thickness t of the filler 50f from the support surface 32a. According to this embodiment, the resin portion 50 that improves the cooling performance of the coil 40 is easily manufactured.

[0048] Moreover, the second region 52 is preferably a region within 300 μm (d1≦300 μm) from the support surface 32a in the resin part 50. The region within 300 μm from the support surface 32a is a region to which heat is easily transferred from the support surface 32a. For this reason, by making the second region 52, in which the filler 50f having the second orientation angle β of less than 45° is dominant, a thickness within 300 μm from the support surface 32a, it is possible to effectively improve the cooling performance of the coil 40.

[0049] As shown in FIG. 4, the inclination angle of the filler 50f in the length direction with respect to the protruding portion side surface 33a as viewed from the axial direction AD of the central axis J is defined as the third orientation angle γ. In this embodiment, it is preferable that the number of fillers 50f included in the third region 53 having a third orientation angle γ of less than 45° is greater than the number of fillers 50f included in the third region 53 having a third orientation angle γ of 45° or more. By setting the third orientation angle γ of the filler 50f in the third region 53 to less than 45°, it becomes easier to arrange a wider area of ​​the filler 50f closer to the protruding portion side surface 33a. Therefore, the heat transferred from the coil 40 to the resin portion is more easily transferred from the resin portion 50 to the protruding portion 33, and as a result, the coil 40 is more easily cooled. The inclination angle of the filler 50f in the length direction with respect to the protruding portion side surface 33a as viewed from the axial direction AD of the central axis J is defined as the third orientation angle γ.

[0050] Moreover, in the third region 53, the filler 50f having a third orientation angle γ of less than 45° is likely to be arranged such that the longitudinal direction of the filler 50f is along the radial direction RD. According to this embodiment, in the third region 53 along the protruding portion side surface 33a, heat is likely to flow in the radial direction RD and is unlikely to flow in the circumferential direction θ. That is, according to this embodiment, the thermal conductivity of the third region 53 in the radial direction RD is greater than the thermal conductivity in the circumferential direction θ. Therefore, in the third region 53, heat can be dispersed in the radial direction of the resin portion 50, and the heat of the resin portion 50 can be transferred to the entire radial direction RD of the protruding portion 33 adjacent to the third region 53. According to this embodiment, the heat of the coil 40 is likely to be transferred to the protruding portion 33 via the resin portion 50, and the coil 40 can be efficiently cooled.

[0051] In the present embodiment, the case has been described where 50% or more of the fillers 50f in the third region 53 have a third orientation angle γ of less than 45°. However, it is more preferable that 60% or more of the fillers 50f in the third region 53 have a third orientation angle γ of less than 45°, and it is even more preferable that 70% or more of the fillers 50f in the third region 53 have a third orientation angle γ of less than 45°. In this way, by increasing the ratio of the fillers 50f in the third region 53 having a third orientation angle γ of less than 45°, the cooling efficiency of the coil 40 can be further improved.

[0052] As described above, the third region 53 is a region along the protruding portion side surface 33a and a region at a certain distance from the protruding portion side surface 33a. When the filler 50f is plate-shaped as in this embodiment, the third region 53 is a region in the resin part 50 that is within 3 times the thickness t of the filler 50f from the protruding portion side surface 33a (d1≦3×t). When the filler 50f is plate-shaped, the region within 3 times the thickness t of the filler 50f is a region where the filler 50f is likely to come into contact with the protruding portion side surface 33a and is likely to directly receive heat from the protruding portion side surface 33a. For this reason, by including the third region 53 in which the filler 50f with a third orientation angle γ of less than 45° is dominant in such a thickness, the filler 50f can actively transfer heat to the protruding portion 33. In addition, when the filler 50f is plate-shaped, it is easy to control the third orientation angle γ of the filler 50f if it is within a range of about 3 times the thickness t of the filler 50f from the protruding portion side surface 33a. According to this embodiment, the resin portion 50 that improves the cooling performance of the coil 40 is easily manufactured.

[0053] Moreover, the third region 53 is preferably a region within 300 μm (d1≦300 μm) from the protruding portion side surface 33a in the resin part 50. The region within 300 μm from the protruding portion side surface 33a is a region to which heat is easily transferred from the protruding portion side surface 33a. For this reason, by making the third region 53, in which the filler 50f having the third orientation angle γ of less than 45° is dominant, a thickness within 300 μm from the protruding portion side surface 33a, it is possible to effectively improve the cooling performance of the coil 40.

[0054] In this embodiment, the first orientation angle α, the second orientation angle β, and the third orientation angle γ are angles defined when viewed from the axial direction. Therefore, the first orientation angle α, the second orientation angle β, and the third orientation angle γ can be identified by cutting the stator 30 along a plane perpendicular to the axial direction and observing the posture of the filler 50f in the resin part 50.

[0055] FIG. 6 is an example of a flowchart of a method for manufacturing the stator 30 included in the rotating electric machine 1 according to the present embodiment. The method for manufacturing the stator 30 included in the rotating electric machine 1 according to the present embodiment includes, for example, a resin application step S10, a coil attachment step S20, a resin hardening step S30, a jig removal step S40, and a resin addition step S50. The resin application step S10, the coil attachment step S20, the resin hardening step S30, the jig removal step S40, and the resin addition step S50 are performed in this order. The jig removal step S40 may be performed before the resin hardening step S30. The method for manufacturing the stator 30 described here is merely an example, and the stator 30 may be manufactured by other manufacturing methods. In addition, some steps may be changed or deleted in the method for manufacturing the stator 30 described here. For example, the resin addition step S50 may not be performed.

[0056] In the manufacturing method of the stator 30 included in the rotating electric machine 1 according to this embodiment, the stator core 31 and the coil 40 are prepared in advance. The stator core 31 is formed by stacking a plurality of steel plates in the thickness direction, which are formed by, for example, press punching or wire electric discharge machining. The coil 40 is formed by winding the coil wire 42e into a coil shape.

[0057] The resin application step S10 is a step of applying an uncured resin portion 50 to the inner circumference of the stator core 31. The uncured resin portion 50 already contains a filler 50f. Therefore, the uncured resin portion 50 has sufficient viscosity to be held on the surface of the stator core 31. The resin portion 50 is applied to the support surface 32a of the core back portion 32 and the protruding portion side surface 33a of the protruding portion 33.

[0058] The coil attachment process S20 is a process of attaching the coil 40 to the stator core 31. As shown in Fig. 3, in the coil attachment process S20, the coil 40 is disposed between the protrusions 33 arranged in the circumferential direction. Also, in the coil attachment process S20, the coil 40 is pressed against the support surface 32a of the core back portion 32.

[0059] The coil attachment step S20 is performed, for example, using a jig 9 (see FIG. 7) that holds the coil 40. The jig 9 holds the coil side surfaces 40a on both circumferential sides of the coil 40 with a pair of claws 9a. The jig 9 also applies pressure to the radially inner side (+RD) of the coil 40 with a pressure applying portion, thereby pressing the coil 40 against the support surface 32a.

[0060] The resin curing step S30 is a step of curing the adhesive 50b contained in the uncured resin part 50. When the adhesive 50b contains a thermosetting resin, the resin curing step S30 is a step of applying heat to the resin part 50. When the adhesive 50b contains an ultraviolet-curable resin, the resin curing step S30 is a step of irradiating the resin part 50 with ultraviolet rays. When the adhesive 50b is naturally curable, the resin curing step S30 is a step of waiting for a predetermined time. The resin curing step S30 can be performed at atmospheric pressure, but may also be performed under reduced pressure or under pressure. These pressurization and depressurization may also be combined. By appropriately controlling the pressure at which the resin curing step S30 is performed, air bubbles can be effectively removed and voids formed in the resin part 50 can be suppressed, and excellent mechanical strength and heat conductivity can be obtained.

[0061] It is preferable that the pressure by the jig 9 is continued until the resin curing step S30 is completed. The holding of the coil 40 by the claw portion 9a of the jig 9 may be released when the resin curing step S30 is performed. The claw portion 9a continues to be disposed between the coil side surface 40a and the protruding portion side surface 33a until the resin curing step S30 is completed. In the resin curing step S30, there is a space between the claw portion 9a and the coil side surface 40a that does not directly contact. Similarly, in the resin curing step S30, there is a space between the claw portion 9a and the protruding portion side surface 33a that does not directly contact. In the resin curing step S30, before the resin portion 50 is cured, a part of the resin portion 50 flows between the claw portion 9a and the coil side surface 40a and between the claw portion 9a and the protruding portion side surface 33a and cures. The filler 50f in the resin portion 50 flows into the narrow gap and is oriented in the direction in which the gap extends. Due to this action, the filler 50f in the resin part 50 is arranged along each surface of the gap into which the resin part 50 is introduced. As a result, the first orientation angle α, the second orientation angle β, and the third orientation angle γ of the resin part 50 are reduced. According to the manufacturing method of the stator 30 included in the rotating electric machine 1 according to the present embodiment, the orientation angle of the filler 50f can be controlled in this manner. Furthermore, by maintaining this state and hardening the adhesive 50b of the resin part 50, the orientation angle of the filler 50f is fixed. In the manufacturing method described here, the length of the filler 50f in the longitudinal direction is preferably greater than the thickness t of the filler 50f, and is preferably 1 μm or more and 10 mm or less. This can improve the controllability of the filler orientation angle.

[0062] 7 is a schematic diagram showing the jig removal step S40. The jig removal step S40 is a step of removing the jig 9 from the cured resin part 50. In order to smoothly perform the jig removal step S40, it is preferable that the surface of the claw portion 9a of the jig 9 is subjected to some kind of surface treatment that promotes demolding. By going through the jig removal step S40, a recess 59 is formed in the portion of the cured resin part 50 where the claw portion 9a was located. The recess 59 opens radially outward.

[0063] FIG. 8 is a schematic diagram showing the resin adding step S50. The resin adding step S50 is a step of filling the recess 59 formed in the jig removing step S40 with the additional resin part 50. The additional resin part 50 corresponds to the fourth region 54 shown in FIG. 3. In this embodiment, the resin part 50 in the fourth region 54 filled in the recess 59 is composed of the same filler 50f and adhesive 50b as the resin parts 50 in the other regions (the first region 51, the second region 52, and the third region 53). The resin part 50 in the fourth region 54 may have a different configuration from the other regions. As an example, the resin part 50 in the fourth region 54 may not contain the filler 50f, and the filler contained therein may be a filler different from that in the other regions, such as a spherical filler. Furthermore, a different adhesive 50b may be used. The resin part 50 filled in the recess 59 in the resin adding step S50 is cured by a resin curing step performed separately. Through the above steps, the stator 30 included in the rotating electric machine 1 according to this embodiment can be manufactured.

[0064] In the manufacturing method of the rotating electric machine 1 of the present embodiment, a case has been described in which there is a gap between the coil 40 and the protruding portion 33 that is wide enough to accommodate the claw portion 9a of the jig 9. However, when the gap between the coil 40 and the protruding portion 33 is narrow, the claw portion 9a does not need to be disposed in this gap.

[0065] Further, in the rotating electric machine 1 of the present embodiment, the case where the stator core 31 has the protruding portion 33 has been described, but the stator core 31 does not necessarily have to have the protruding portion 33.

[0066] Fig. 9 is a schematic diagram of a resin part 150 according to a first modified example that can be employed in the rotating electric machine 1 according to the embodiment described above. Fig. 9 is a first modified example of an enlarged view of a region IV shown in Fig. 3. As shown in Fig. 9, the resin part 150 may have an elliptical spherical filler 150f. Note that the elliptical spherical shape here includes not only those having an elliptical spherical shape in the strict sense, but also those having a shape that can be regarded as an elliptical spherical shape.

[0067] Fig. 10 is a schematic diagram of a resin part 250 according to a second modified example that can be used in the rotating electric machine 1 according to the above-described embodiment. Fig. 10 is a schematic diagram of a second modified example of an enlarged view of an area IV shown in Fig. 3. As shown in Fig. 10, the resin part 250 may have needle-shaped filler 250f.

[0068] According to at least one of the embodiments described above, a rotating electric machine 1 can be provided that can efficiently transfer heat from the coil 40 to the stator core 31 by having a resin part 50 with increased thermal conductivity in the radial direction RD of the first region 51 along the coil side surface 40a.

[0069] The rotating electric machine can be mounted on various drive objects such as automobiles, trains, and aircraft. Fig. 11 is a schematic diagram of an aircraft 90 as an example of a drive object on which a rotating electric machine 1 is mounted. The aircraft 90 is a hybrid aircraft propelled by a combination of a jet engine 91 and the rotating electric machine 1. The aircraft 90 has a pair of jet engines 91 and four rotating electric machines 1. The jet engines 91 are provided on main wings 98. The jet engines 91 generate thrust by exhausting air rearward.

[0070] The four rotating electric machines 1 are classified into two power generating rotating electric machines 1A and two drive rotating electric machines 1B. The power generating rotating electric machines 1A are each connected to the main shaft of a jet engine 91. The power generating rotating electric machine 1A generates electricity by the jet engine 91. Meanwhile, the drive rotating electric machine 1B is disposed below the vertical tail 99. The drive rotating electric machine 1B rotates a propulsion fan 93 to send air rearward and generate thrust. The drive rotating electric machine 1B is driven by electric power generated by the power generating rotating electric machine 1A. Note that if the power generating rotating electric machine 1A generates surplus electric power, this electric power may be charged into a battery and used when necessary.

[0071] Although some embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These embodiments can be implemented in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their modifications are included in the scope of the invention and its equivalents described in the claims, as well as in the scope and spirit of the invention. [Explanation of symbols]

[0072] Reference Signs List 1... rotating electric machine, 20... rotor, 30... stator, 31... stator core, 32... core back portion, 32a... support surface, 33... protruding portion, 33a... protruding portion side surface, 40... coil, 40a... coil side surface, 42e... coil wire, 50, 150, 250... resin portion, 50f, 150f, 250f... filler, 51... first region, 52... second region, 53... third region, AD... axial direction, J... central axis, RD... radial direction, t... thickness, α... first orientation angle, β... second orientation angle, γ... third orientation angle, θ... circumferential direction

Claims

1. An annular stator centered on a central axis; a rotor located on one radial side of the stator and supported rotatably about the central axis, The stator includes: a stator core having an annular core back portion centered on the central axis line; a coil formed by bundling a plurality of coil wires and disposed on one radial side of the core back portion; a resin portion that fixes the coil to the stator core, The resin portion is A first region extending radially along a coil side surface facing a circumferential direction of the coil; a second region extending in a circumferential direction along a support surface facing one radial side of the core back portion, The resin portion includes a filler, The thermal conductivity of the first region in a radial direction is greater than the thermal conductivity in a circumferential direction. Rotating electric motor.

2. The thermal conductivity of the second region in the circumferential direction is greater than the thermal conductivity in the radial direction. The rotating electric machine according to claim 1 .

3. the stator core has a protruding portion protruding from the core back portion to one side in a radial direction and facing the coil in a circumferential direction, the resin portion has a third region extending radially along a circumferentially facing protruding portion side surface, The thermal conductivity of the third region in a radial direction is greater than the thermal conductivity in a circumferential direction. The rotating electric machine according to claim 1 .

4. An annular stator centered on a central axis; a rotor located on one radial side of the stator and supported rotatably about the central axis, The stator includes: a stator core having an annular core back portion centered on the central axis line; a coil formed by bundling a plurality of coil wires and disposed on one radial side of the core back portion; a resin portion that fixes the coil to the stator core, The resin portion is A first region extending radially along a coil side surface facing a circumferential direction of the coil; a second region extending in a circumferential direction along a support surface facing one radial side of the core back portion, The resin portion includes a filler, a first orientation angle is an inclination angle of the filler in a longitudinal direction with respect to a side surface of the coil as viewed in an axial direction of the central axis; Among the fillers contained in the first region, those having the first orientation angle of less than 45° are more numerous than those having the first orientation angle of 45° or more. Rotating electric motor.

5. The filler is plate-shaped, The first region is a region in the resin portion that is within three times the thickness of the filler from the side surface of the coil. The rotating electric machine according to claim 4.

6. The first region is a region within 300 μm from a side surface of the coil in the resin portion. The rotating electric machine according to claim 4.

7. When viewed in the axial direction of the central axis, an inclination angle of the length direction of the filler with respect to the support surface is defined as a second orientation angle; Among the fillers contained in the second region, those having the second orientation angle of less than 45° are more numerous than those having the second orientation angle of 45° or more. The rotating electric machine according to claim 4.

8. The filler is plate-shaped, The second region is a region in the resin portion that is within three times the thickness of the filler from the support surface. The rotating electric machine according to claim 7.

9. The second region is a region of the resin portion within 300 μm from the support surface. The rotating electric machine according to claim 7.

10. the stator core has a protruding portion protruding from the core back portion to one side in a radial direction and facing the coil in a circumferential direction, the resin portion has a third region extending radially along a circumferentially facing protruding portion side surface, When viewed from the axial direction of the central axis, an inclination angle of the filler in the length direction with respect to the protruding portion side surface is defined as a third orientation angle; Among the fillers contained in the third region, those having the third orientation angle of less than 45° are more numerous than those having the third orientation angle of 45° or more. The rotating electric machine according to claim 4.

11. The filler is plate-shaped, The third region is a region in the resin portion that is within three times the thickness of the filler from the side surface of the protruding portion. The rotating electric machine according to claim 10.

12. The third region is a region within 300 μm from a side surface of the protrusion in the resin portion. The rotating electric machine according to claim 10.

13. The filler is an oval sphere. The rotating electric machine according to claim 4.

14. The filler is acicular. The rotating electric machine according to claim 4.

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