Motor

Abstract

This motor comprises: a rotor that can rotate around a central axis; a stator that is disposed on the outer side in a radial direction of the rotor and faces the rotor with separation therebetween in the radial direction; a cylindrical heat-transfer member that surrounds the central axis; and a housing that accommodates the rotor, the stator, and the heat-transfer member. The housing comprises a cylindrical peripheral wall section that surrounds the stator from the outer side in the radial direction and a protruding section that protrudes from an inner peripheral surface of the peripheral wall section inward in the radial direction. The stator comprises an annular stator core and a coil section that is mounted on the stator core. The coil section comprises a first coil end that protrudes from the stator core toward one side in the axial direction and a second coil end that protrudes from the stator core toward the other side in the axial direction. At least part of the heat-transfer member is disposed between the first coil end and the peripheral wall section in the radial direction. The protruding section is located further to the other side in the axial direction than the second coil end and faces the second coil end in the axial direction.

Description

Motor

[0001] This application claims priority from Japanese Patent Application No. 2024-104046, filed on June 27, 2024, the contents of which are incorporated herein by reference.

[0002] 2. Description of the Related Art A rotating electrical machine is known that includes a stator having a stator core and a coil wound around the stator core, and the stator core is fixed to a device casing (see, for example, Patent Document 1).

[0003] Japanese Patent Application Laid-Open No. 2020-137178

[0004] In the rotating electrical machine described in Patent Document 1, Joule heat generated in the coil is transferred to the device casing via the stator core and dissipated to the outside of the rotating electrical machine. Because of the high thermal resistance between the stator core and the coil ends, which are the portions of the coil that protrude from the stator core, the Joule heat generated in the coil ends is difficult to transfer to the stator core. Therefore, there is a risk that the temperature of the coil ends will become too high. Furthermore, if the temperature of the coil ends becomes too high, there is a risk that the coils will deteriorate.

[0005] In view of the above circumstances, one aspect of the present invention has an object to provide a motor that can prevent the temperature of the coil ends from becoming too high.

[0006] One aspect of the motor of the present invention includes a rotor rotatable about a central axis, a stator disposed radially outward of the rotor and facing the rotor with a radial gap therebetween, a cylindrical heat transfer member surrounding the central axis, and a housing accommodating the rotor, the stator, and the heat transfer member. The housing has a cylindrical peripheral wall portion surrounding the stator from the radially outer side, and a protrusion connected to the peripheral wall portion and protruding radially inward from an inner peripheral surface of the peripheral wall portion. The stator has an annular stator core surrounding the central axis, and a coil portion attached to the stator core. The coil portion has a first coil end protruding axially from the stator core and a second coil end protruding axially from the stator core. At least a portion of the heat transfer member is disposed radially between the first coil end and the peripheral wall portion. The protrusion is located axially on the other side of the second coil end and faces the second coil end in the axial direction.

[0007] According to one aspect of the present invention, it is possible to prevent the temperature of the coil ends in a motor from becoming too high.

[0008] FIG. 1 is a perspective view showing a motor of a first embodiment. FIG. 2 is a cross-sectional view showing the motor of the first embodiment. FIG. 3 is an enlarged cross-sectional view showing a portion of the motor of the first embodiment. FIG. 4 is a cross-sectional view showing the motor of the first embodiment, taken along line IV-IV in FIG. 2. FIG. 5 is a perspective view showing a portion of the motor of the first embodiment. FIG. 6 is a cross-sectional view showing a motor of a second embodiment. FIG. 7 is an enlarged cross-sectional view showing a portion of the motor of the second embodiment. FIG. 8 is a cross-sectional view showing a motor of a third embodiment. FIG. 9 is an enlarged cross-sectional view showing a portion of the motor of the third embodiment.

[0009] Hereinafter, motors according to embodiments of the present invention will be described with reference to the drawings. Note that the scope of the present invention is not limited to the following embodiments, and can be modified as desired within the scope of the technical concept of the present invention. In addition, in the following drawings, the scale and number of components may differ from the actual structure in order to make each component easier to understand.

[0010] In the following description, the Z axis is indicated in the figures as appropriate. The Z axis is the direction in which the central axis J of the embodiment described below extends. The central axis J shown in each figure is a virtual axis. In the following description, the direction in which the central axis J extends, i.e., the direction parallel to the Z axis, is referred to as the "axial direction." The radial direction centered on the central axis J is simply referred to as the "radial direction." The circumferential direction centered on the central axis J is simply referred to as the "circumferential direction." The circumferential direction is indicated by an arrow θ in each figure. The side of the axial direction toward which the Z axis arrow points (+Z side) is referred to as the "upper side" or "one axial side." The side of the axial direction opposite to the side toward which the Z axis arrow points (-Z side) is referred to as the "lower side" or "other axial side." Note that the terms "upper side" and "lower side" are simply names used to describe the relative positional relationships of the various components, and the actual positional relationships may be other than those indicated by these names.

[0011] First Embodiment As shown in Fig. 1 , a motor 10 of this embodiment is a disk-shaped motor centered on a central axis J. The motor 10 of this embodiment is mounted on, for example, an unmanned aerial vehicle and used as a drive device for rotating rotors of the unmanned aerial vehicle about the central axis J. The motor 10 is a thin motor whose axial dimension is smaller than its radial dimension. As shown in Fig. 2 , the motor 10 includes a housing 11, a heat transfer member 30, a rotor 40, a shaft 44, a stator 50, a resin part 60, and a busbar unit 70.

[0012] The housing 11 has a substantially cylindrical shape centered on a central axis J. The housing 11 accommodates the heat transfer member 30, the rotor 40, the stator 50, the resin part 60, and the busbar unit 70 therein. The housing 11 is made of metal. In this embodiment, the housing 11 is made of aluminum. The housing 11 may be made of a material other than aluminum. The housing 11 has a peripheral wall part 14, a protrusion part 15, a cover member 16, a bottom plate part 18, and a heat dissipation part 21.

[0013] The peripheral wall portion 14 has a generally cylindrical shape extending in the axial direction around the central axis J. The peripheral wall portion 14 surrounds the heat transfer member 30, the rotor 40, the stator 50, the resin portion 60, and the busbar unit 70 from the radially outer side. The peripheral wall portion 14 is open on both sides in the axial direction. The peripheral wall portion 14 has an opening 14a on the upper side, i.e., on one axial side. The peripheral wall portion 14 has a second opening 14c on the lower side. The peripheral wall portion 14 is provided with a stepped surface 14e.

[0014] As shown in Fig. 3, the step surface 14e is a surface provided on the inner peripheral surface of the peripheral wall portion 14 facing upward, i.e., toward one axial side. When viewed from the axial direction, the step surface 14e has a substantially annular shape centered on the central axis J. As shown in Fig. 2, the inner diameter of the portion of the peripheral wall portion 14 above the step surface 14e is smaller than the inner diameter of the portion of the peripheral wall portion 14 below the step surface 14e.

[0015] The protrusion 15 protrudes radially inward from the inner peripheral surface of the peripheral wall portion 14. The protrusion 15 is in the shape of a substantially annular plate centered on the central axis J. The plate surface of the protrusion 15 faces the axial direction. The protrusion 15 is connected to the peripheral wall portion 14. In this embodiment, the peripheral wall portion 14 and the protrusion 15 are part of a single member. The protrusion 15 is arranged below the stator 50. The protrusion 15 faces the stator 50 with a gap in the axial direction. The protrusion 15 is arranged above the busbar unit 70.

[0016] The cover member 16 has a substantially annular plate shape centered on the central axis J. The plate surface of the cover member 16 faces the axial direction. The cover member 16 is fixed to the upper end of the peripheral wall portion 14. As a result, the cover member 16 closes the opening 14a from above, i.e., from one axial side. The cover member 16 is provided with a hole portion 16a and a first bearing holder portion 16c. The hole portion 16a is a hole that penetrates the cover member 16 in the axial direction. When viewed in the axial direction, the hole portion 16a has a circular shape centered on the central axis J.

[0017] The first bearing holder 16c protrudes downward from the cover member 16. The first bearing holder 16c is generally cylindrical and has its center on the central axis J. The first bearing holder 16c opens downward. A first bearing 75 is attached to the inner peripheral surface of the first bearing holder 16c. The first bearing 75 is generally annular and has its center on the central axis J.

[0018] The bottom plate portion 18 is substantially circular and centered on the central axis J. The bottom plate portion 18 is plate-shaped and extends in a direction intersecting the axial direction. In this embodiment, the bottom plate portion 18 is plate-shaped and extends in a direction perpendicular to the axial direction. The bottom plate portion 18 may also be plate-shaped and extends in a direction tilted from the axial direction. The bottom plate portion 18 is fixed to the lower end of the peripheral wall portion 14. As a result, the bottom plate portion 18 blocks the second opening 14c from below. The bottom plate portion 18 is positioned below the protruding portion 15, i.e., on the other axial side. The bottom plate portion 18 is positioned with a gap between it and the protruding portion 15 in the axial direction. A second bearing holder 18a is provided on the bottom plate portion 18.

[0019] The second bearing holder 18a protrudes upward from the bottom plate 18. The second bearing holder 18a is generally cylindrical and has its center on the central axis J. The second bearing holder 18a opens upward. A second bearing 76 is attached to the inner circumferential surface of the second bearing holder 18a. The second bearing 76 is generally annular and has its center on the central axis J.

[0020] As shown in Fig. 4, the heat dissipation portion 21 protrudes radially outward from the outer peripheral surface of the peripheral wall portion 14. As shown in Fig. 1, the heat dissipation portion 21 is in the form of a plate extending in the axial direction. The plate surface of the heat dissipation portion 21 faces the circumferential direction. As shown in Fig. 2, the upper end of the heat dissipation portion 21 is located at the same position as the upper end of the peripheral wall portion 14 in the axial direction. The lower end of the heat dissipation portion 21 is located at the same position as the lower end of the peripheral wall portion 14 in the axial direction. When viewed from the radial direction, the heat dissipation portion 21 overlaps with the stator 50 and the protruding portion 15. That is, when viewed from the radial direction, the protruding portion 15 overlaps with the heat dissipation portion 21.

[0021] As shown in FIG. 1 , the housing 11 has a plurality of heat dissipation portions 21. The heat dissipation portions 21 are spaced apart from one another in the circumferential direction. This increases the surface area of ​​the outer surface of the housing 11, thereby increasing the amount of heat dissipated from the housing 11 to the outside of the motor 10. Note that each heat dissipation portion 21 may be in the form of a plate extending in the circumferential direction along the outer circumferential surface of the peripheral wall portion 14. In this case, the heat dissipation portions 21 are spaced apart from one another in the axial direction.

[0022] 2, the rotor 40 has a substantially circular ring shape centered on a central axis J. The rotor 40 is rotatable about the central axis J. The rotor 40 faces the stator 50 with a radial gap therebetween. The rotor 40 has a magnet holder 41, magnets 42, and blade members 46.

[0023] The magnet holder 41 is annular and surrounds the central axis. In this embodiment, the magnet holder 41 is made of, for example, aluminum. The magnet holder 41 may be made of other materials. More specifically, the magnet holder 41 is approximately annular and centered on the central axis J. The magnet 42 is approximately annular and centered on the central axis J. The magnet 42 is fixed to a surface of the magnet holder 41 that faces radially outward. The magnet 42 has magnetic poles that face radially. The magnet 42 faces the stator 50 with a radial gap between them.

[0024] The blade members 46 are plate-shaped and extend in a direction intersecting the circumferential direction. In this embodiment, the blade members 46 are plate-shaped and extend in a direction perpendicular to the circumferential direction. When viewed in the circumferential direction, the blade members 46 are substantially rectangular. In this embodiment, the rotor 40 has a plurality of blade members 46. The plurality of blade members 46 includes a plurality of first blade members 47 and a plurality of second blade members 48. Note that the rotor 40 does not necessarily have to have a plurality of blade members 46. Furthermore, the plurality of blade members 46 may include only one of the plurality of first blade members 47 and the plurality of second blade members 48.

[0025] Each of the multiple first blade members 47 is located above the magnet 42, i.e., on one axial side. Each first blade member 47 is fixed to the surface of the magnet 42 facing upward. As shown in FIG. 5 , each first blade member 47 is arranged at intervals along the circumferential direction. When the rotor 40 rotates about the central axis J, each first blade member 47 revolves around the central axis J. Therefore, as shown in FIG. 3 , when the rotor 40 rotates about the central axis J, each first blade member 47 generates airflow AF1 that flows radially outward. The airflow AF1 flows toward the stator 50, and thus the stator 50 can be cooled by the airflow AF1.

[0026] As shown in FIG. 2 , each of the multiple second blade members 48 is located below the magnet 42, i.e., on the other axial side. Each second blade member 48 is fixed to a surface of the magnet 42 facing downward. Although not shown, similar to the first blade members 47 described above, each second blade member 48 is spaced apart along the circumferential direction. When the rotor 40 rotates about the central axis J, each second blade member 48 revolves around the central axis J. Therefore, as shown in FIG. 3 , when the rotor 40 rotates about the central axis J, each second blade member 48 generates airflow AF2 that flows radially outward. Because the airflow AF2 flows toward the stator 50, the airflow AF2 can cool the stator 50.

[0027] As shown in FIG. 2 , the shaft 44 is generally cylindrical and extends axially around the central axis J. The shaft 44 is positioned radially inward of the rotor 40 and the stator 50. The shaft 44 passes axially through the magnet holder 41. The outer circumferential surface of the shaft 44 is fixed to the inner circumferential surface of the magnet holder 41. This allows the shaft 44 to rotate together with the rotor 40 around the central axis J. The upper end of the shaft 44 protrudes outside the housing 11 through the hole 16a. The upper portion of the shaft 44 is rotatably supported by a first bearing 75 around the central axis J. The lower portion of the shaft 44 is rotatably supported by a second bearing 76 around the central axis J. A rotor (not shown) of the unmanned aerial vehicle is fixed to the shaft 44. This allows the rotor to rotate around the central axis J when the shaft 44 rotates around the central axis J. When the rotor rotates around the central axis J, the unmanned aerial vehicle can fly.

[0028] The stator 50 is disposed radially outward of the rotor 40. The stator 50 faces the rotor 40 with a gap therebetween in the radial direction. The stator 50 includes a stator core 51, an insulator 52, and a coil portion 54.

[0029] The stator core 51 has an annular shape surrounding the central axis J. More specifically, the stator core 51 has a substantially circular shape centered on the central axis J. The stator core 51 surrounds the rotor 40 from the radially outer side. The stator core 51 faces the rotor 40 with a gap therebetween in the radial direction. As shown in FIG. 4 , the stator core 51 has a core back portion 51 a and teeth portions 51 c.

[0030] The core back portion 51a has a substantially circular ring shape centered on the central axis J. The outer peripheral surface of the core back portion 51a is fixed to the inner peripheral surface of the peripheral wall portion 14. This fixes the stator 50 to the housing 11. As shown in FIG. 3 , the core back portion 51a is located above the stepped surface 14e. The surface of the core back portion 51a facing downward is in axial contact with the stepped surface 14e. In other words, the surface of the stator core 51 facing the lower side, i.e., the other axial side, is in axial contact with the stepped surface 14e.

[0031] According to this embodiment, the inner circumferential surface of the peripheral wall portion 14 is provided with a stepped surface 14e facing upward, i.e., toward one axial side, and the lower surface of the stator core 51, i.e., facing the other axial side, is in axial contact with the stepped surface 14e. Therefore, during the assembly process of the motor 10, the axial position of the stator 50 relative to the housing 11 can be determined by the simple operation of inserting the stator 50 into the peripheral wall portion 14 through the opening 14a of the housing 11 and bringing the lower surface of the stator core 51 into contact with the stepped surface 14e. This effectively prevents an increase in the number of steps required to assemble the motor 10.

[0032] As shown in Fig. 4, the teeth 51c protrude radially inward from the core back portion 51a. The teeth 51c face the magnets 42 of the rotor 40 at intervals in the radial direction. The stator core 51 has a plurality of teeth 51c. In this embodiment, the stator core 51 has 72 teeth 51c. The number of teeth 51c included in the stator core 51 may be 71 or less, or 73 or more. The teeth 51c are arranged at approximately equal intervals along the circumferential direction.

[0033] 2 insulates the stator core 51 from the coil portion 54. The insulator 52 is attached to the stator core 51. In this embodiment, the insulator 52 is attached to each tooth portion 51c.

[0034] The coil portions 54 are attached to the tooth portions 51c via the insulators 52. As a result, the coil portions 54 are attached to the stator core 51. The coil portions 54 are formed by coils wound around the tooth portions 51c. The stator 50 has a plurality of coil portions 54. As shown in FIG. 4 , in this embodiment, the stator 50 has 72 coil portions 54. Each coil portion 54 is attached to a different tooth portion 51c. The coil portions 54 are arranged at approximately equal intervals along the circumferential direction. Each coil portion 54 is electrically connected to a power supply device (not shown) of the unmanned aerial vehicle via the busbar unit 70. When current is supplied to each coil portion 54 from the power supply device, each coil portion 54 forms an electromagnet with its magnetic poles facing radially. When current is supplied to the coil portions 54, Joule heat is generated in the coil portions 54. As a result, the temperature of the coil portions 54 increases when the motor 10 is driven. That is, the temperature of the stator 50 increases when the motor 10 is driven. As shown in FIG.

[0035] The coil ends 55 are portions of the coil portion 54 that protrude axially from the stator core 51. Therefore, the thermal resistance between the coil ends 55 and the stator core 51 is likely to be greater than the thermal resistance between the stator core 51 and portions of the coil portion 54 other than the coil ends 55. Furthermore, as described above, when current is supplied to the coil portion 54, Joule heat is generated in the coil portion 54. Because the Joule heat generated in the coil ends 55 is not easily transferred to the housing 11 via the stator core 51, the temperature of the coil ends 55 is likely to rise. The coil ends 55 have a first coil end 55a and a second coil end 55c. That is, the coil portion 54 has a first coil end 55a and a second coil end 55c.

[0036] 3, the first coil end 55a is a portion of the coil portion 54 that protrudes upward from the stator core 51, i.e., to one axial side. A portion of the insulator 52 is disposed between the first coil end 55a and the peripheral wall portion 14. That is, a portion of the insulator 52 is disposed between the peripheral wall portion 14 and the first coil end 55a. When viewed radially, the first coil end 55a overlaps an upper portion of the heat dissipation portion 21. That is, when viewed radially, the first coil end 55a overlaps with the heat dissipation portion 21.

[0037] The second coil end 55c is a portion of the coil portion 54 that protrudes downward from the stator core 51, i.e., toward the other axial side. When viewed radially, the second coil end 55c overlaps with a lower portion of the heat dissipation portion 21. That is, when viewed radially, the second coil end 55c overlaps with the heat dissipation portion 21. The second coil end 55c is located above the protruding portion 15. That is, the protruding portion 15 is located below the second coil end 55c, i.e., toward the other axial side. The protruding portion 15 faces the second coil end 55c in the axial direction. The radially inner end of the protruding portion 15 is located radially inward of the second coil end 55c. As a result, when viewed axially, the entire second coil end 55c overlaps with the protruding portion 15. Note that in this embodiment, it is sufficient that only a portion of the second coil end 55c overlaps with the protruding portion 15 when viewed axially. In this case, the radially inner end of the protruding portion 15 is located radially outward of the radially inner end of the second coil end 55c.

[0038] As described above, when the rotor 40 rotates about the central axis J, each first blade member 47 generates wind AF1 that flows radially outward. Because each first blade member 47 is located above the magnet 42, wind AF1 flows toward the first coil end 55a. Also, as described above, when the rotor 40 rotates about the central axis J, each second blade member 48 generates wind AF2 that flows radially outward. Because each second blade member 48 is located below the magnet 42, wind AF2 flows toward the second coil end 55c.

[0039] As shown in Fig. 2, the busbar unit 70 electrically connects the stator 50 to a power supply device (not shown) of the unmanned aerial vehicle. The busbar unit 70 has a substantially circular ring shape centered on the central axis J. In the axial direction, the busbar unit 70 is disposed between the protruding portion 15 and the bottom plate portion 18. The busbar unit 70 has a busbar holder 71 and a plurality of busbars 72.

[0040] The bus bar holder 71 has a substantially circular ring shape centered on the central axis J. The bus bar holder 71 is made of resin. The bus bar holder 71 holds each bus bar 72. The bus bar holder 71 insulates each bus bar 72 from one another.

[0041] Each bus bar 72 extends in the circumferential direction. In this embodiment, currents of different phases are supplied to each bus bar 72. Although not shown, each bus bar 72 is electrically connected to a power supply device. Each bus bar 72 is electrically connected to each coil portion 54 of the stator 50. In other words, the bus bar unit 70 is electrically connected to the coil portions 54 and the power supply device. As a result, current is supplied from the power supply device to each coil portion 54.

[0042] When current is sequentially supplied to each of the multiple coil portions 54 of the stator 50 from a power supply (not shown), the coil portions 54 sequentially form electromagnets with magnetic poles facing radially. As a result, a rotating magnetic field is formed between the magnet 42 of the rotor 40 and each of the teeth 51 c of the stator 50, and the rotor 40 and the shaft 44 each rotate about the central axis J. As a result, the rotor blades fixed to the shaft 44 rotate about the central axis J.

[0043] The heat transfer member 30 transfers heat generated in the first coil end 55a to the peripheral wall portion 14. The heat transfer member 30 has a cylindrical shape surrounding the central axis J. More specifically, the heat transfer member 30 has a substantially cylindrical shape that protrudes in the axial direction centered on the central axis J. In this embodiment, the heat transfer member 30 is made of metal. In this embodiment, the heat transfer member 30 is made of aluminum. The heat transfer member 30 may be made of a material other than aluminum.

[0044] As shown in FIG. 3 , the heat transfer member 30 is disposed above the stator core 51 in the axial direction. In this embodiment, the downward surface of the heat transfer member 30 is in axial contact with the stator core 51. The heat transfer member 30 does not have to be in contact with the stator core 51. In the radial direction, the heat transfer member 30 is disposed between the peripheral wall portion 14 and a portion of the insulator 52 that is above the stator core 51. As a result, a portion of the insulator 52 is disposed between the heat transfer member 30 and the first coil end 55 a in the radial direction. The upper end of the heat transfer member 30 is located above the upper end of the first coil end 55 a. Therefore, at least a portion of the heat transfer member 30 is disposed between the first coil end 55 a and the peripheral wall portion 14 in the radial direction. When viewed in the radial direction, the heat transfer member 30 overlaps with an upper portion of the heat dissipation portion 21. That is, when viewed in the radial direction, the heat transfer member 30 overlaps with the heat dissipation portion 21. The inner circumferential surface of the heat transfer member 30 is located radially inward of the inner circumferential surface of the circumferential wall portion 14. This reduces the thermal resistance between the insulator 52 and the circumferential wall portion 14 compared to a configuration in which the motor 10 does not include the heat transfer member 30. In this embodiment, the inner circumferential surface of the heat transfer member 30 contacts the outer circumferential surface of the insulator 52. That is, the heat transfer member 30 contacts the insulator 52. The outer circumferential surface of the heat transfer member 30 contacts the inner circumferential surface of the circumferential wall portion 14. In this embodiment, the heat transfer member 30 is press-fitted and fixed to the circumferential wall portion 14. The heat transfer member 30 may also be adhesively fixed to the circumferential wall portion 14 with an adhesive.

[0045] As shown in FIG. 2 , the resin portion 60 is in contact with each of the coil ends 55, the heat transfer member 30, and the housing 11. The resin portion 60 transfers heat generated in the coil ends 55 to the heat transfer member 30 and the housing 11. In this embodiment, the resin portion 60 is made of resin. Thermosetting resins such as epoxy resin and silicone resin can be used as materials for the resin portion 60. Note that in this embodiment, the motor 10 does not necessarily have to include the resin portion 60. In this embodiment, the resin portion 60 includes a first resin portion 61 and a second resin portion 62. That is, the motor 10 includes the first resin portion 61 and the second resin portion 62.

[0046] As shown in FIG. 3 , the first resin portion 61 is filled between the first coil end 55 a and the heat transfer member 30 and the peripheral wall portion 14. The first resin portion 61 is in contact with each of the first coil end 55 a, the heat transfer member 30, and the peripheral wall portion 14. More specifically, the first resin portion 61 covers the first coil end 55 a from above. This brings the first resin portion 61 into contact with the first coil end 55 a. The first resin portion 61 is in contact with the surface of the heat transfer member 30 facing upward. This brings the heat transfer member 30 into contact with the first resin portion 61. The first resin portion 61 is in contact with the inner circumferential surface of the peripheral wall portion 14. As described above, in this embodiment, the heat transfer member 30 is made of metal. Therefore, the thermal conductivity of the heat transfer member 30 is greater than that of the first resin portion 61. The material of the heat transfer member 30 is not particularly limited as long as the thermal conductivity of the heat transfer member 30 is greater than the thermal conductivity of the first resin portion 61. The heat transfer member 30 may be made of other materials such as ceramic.

[0047] Since the motor 10 of this embodiment is equipped with the above-mentioned heat transfer member 30 and first resin part 61, the paths by which heat generated in the first coil end 55a is transmitted to the peripheral wall part 14 include the first path R1, the second path R2, and the third path R3.

[0048] The first path R1 is a path that transfers heat generated in the first coil ends 55a to the peripheral wall portion 14 via the insulator 52 and the stator core 51. As described above, the first coil ends 55a protrude above the stator core 51, and therefore the thermal resistance between the first coil ends 55a and the stator core 51 is large. Therefore, it is difficult to increase the amount of heat transferred from the first coil ends 55a to the peripheral wall portion 14 via the first path R1.

[0049] The second path R2 is a path through which heat generated in the first coil end 55a is transferred to the circumferential wall portion 14 via the insulator 52 and the heat transfer member 30. As described above, the inner circumferential surface of the heat transfer member 30 is located radially inward of the inner circumferential surface of the circumferential wall portion 14. Therefore, in this embodiment, the thermal resistance between the insulator 52 and the circumferential wall portion 14 can be reduced compared to a configuration in which the heat transfer member 30 is not disposed between the insulator 52 and the circumferential wall portion 14. Therefore, the amount of heat transferred from the first coil end 55a to the circumferential wall portion 14 via the second path R2 can be increased. Furthermore, as described above, in this embodiment, the heat transfer member 30 contacts the insulator 52, thereby effectively reducing the thermal resistance between the insulator 52 and the heat transfer member 30. Furthermore, in this embodiment, the heat transfer member 30 contacts the circumferential wall portion 14, thereby effectively reducing the thermal resistance between the insulator 52 and the circumferential wall portion 14. Therefore, the amount of heat transferred from the first coil end 55a to the peripheral wall portion 14 via the second route R2 can be more suitably increased.

[0050] The third path R3 is a path through which heat generated in the first coil ends 55 a is transferred to the peripheral wall portion 14 via the first resin portion 61 and the heat transfer member 30. In this embodiment, the amount of heat transferred from the first coil ends 55 a to the heat transfer member 30 via the third path R3 can be increased compared to a configuration in which the motor 10 does not include the first resin portion 61. This effectively increases the amount of heat transferred from the first coil ends 55 a to the peripheral wall portion 14 via the third path R3. As a result, the motor 10 of this embodiment, which includes the heat transfer member 30 and the first resin portion 61, can increase the amount of heat transferred from the first coil ends 55 a to the peripheral wall portion 14. Note that in this embodiment, because the first resin portion 61 contacts the peripheral wall portion 14, a portion of the heat transferred from the first coil ends 55 a to the first resin portion 61 is transferred directly from the first resin portion 61 to the peripheral wall portion 14. This further increases the amount of heat transferred from the first coil end 55a to the peripheral wall portion 14.

[0051] The second resin portion 62 is filled between the second coil end 55c and the protruding portion 15 and the peripheral wall portion 14. The second resin portion 62 contacts each of the second coil end 55c, the protruding portion 15, and the peripheral wall portion 14. More specifically, the second resin portion 62 covers the second coil end 55c from below. This brings the second resin portion 62 into contact with the second coil end 55c. The second resin portion 62 comes into contact with the surface of the protruding portion 15 facing upward. This brings the protruding portion 15 into contact with the second resin portion 62. The radially outer portion of the second resin portion 62 is disposed between the insulator 52 and the peripheral wall portion 14. The radially outer portion of the second resin portion 62 comes into contact with each of the outer peripheral surface of the insulator 52 and the inner peripheral surface of the peripheral wall portion 14. In other words, the second resin portion 62 comes into contact with the inner peripheral surface of the peripheral wall portion 14. As described above, in this embodiment, the housing 11 is made of metal, and therefore the thermal conductivity of the protrusion 15 is greater than the thermal conductivity of the second resin portion 62 .

[0052] Since the motor 10 of this embodiment has the above-mentioned protrusion 15 and second resin part 62, the paths by which heat generated in the second coil end 55c is transmitted to the peripheral wall part 14 include the fourth path R4, the fifth path R5, and the sixth path R6.

[0053] The fourth path R4 is a path that transfers heat generated in the second coil ends 55c to the peripheral wall portion 14 via the insulator 52 and the stator core 51. As described above, the second coil ends 55c protrude downward from the stator core 51, so the thermal resistance between the second coil ends 55c and the stator core 51 is large. Therefore, it is difficult to increase the amount of heat transferred from the second coil ends 55c to the peripheral wall portion 14 via the fourth path R4.

[0054] The fifth path R5 is a path for transferring heat generated in the second coil ends 55c to the peripheral wall portion 14 via the insulator 52 and the second resin portion 62. As described above, in this embodiment, a portion of the second resin portion 62 is disposed between the insulator 52 and the peripheral wall portion 14, thereby reducing the thermal resistance between the insulator 52 and the peripheral wall portion 14. Therefore, compared to a configuration in which the second resin portion 62 is not disposed between the insulator 52 and the peripheral wall portion 14, the amount of heat transferred from the second coil ends 55c to the peripheral wall portion 14 via the fifth path R5 can be suitably increased.

[0055] The sixth path R6 is a path through which heat generated in the second coil ends 55c is transferred to the peripheral wall portion 14 via the second resin portion 62 and the protruding portion 15. As described above, the protruding portion 15 axially faces the second coil ends 55c, allowing the protruding portion 15 to be positioned closer to the second coil ends 55c. This increases the amount of heat transferred from the second coil ends 55c to the protruding portion 15. Therefore, the amount of heat transferred from the second coil ends 55c to the peripheral wall portion 14 via the sixth path R6 can be suitably increased. Furthermore, in this embodiment, the second resin portion 62 contacts both the second coil ends 55c and the protruding portion 15. This allows for a more efficient reduction in thermal resistance between the second coil ends 55c and the protruding portion 15 compared to a configuration in which the motor 10 does not include the second resin portion 62. This allows for a more efficient increase in the amount of heat transferred from the second coil ends 55c to the peripheral wall portion 14 via the sixth path R6. As a result, the motor 10 of this embodiment includes the protrusion 15 and the second resin portion 62, which increases the amount of heat transferred from the second coil end 55c to the peripheral wall portion 14. The heat of the coil end 55 transferred to the peripheral wall portion 14 is dissipated to the outside of the motor 10 via the outer circumferential surface of the peripheral wall portion 14 and the plurality of heat dissipation portions 21.

[0056] In a typical motor, heat from the coil ends 55 is transferred to the circumferential wall portion 14 via a route that passes through the stator core 51, i.e., via the first route R1 and the fourth route R4. In contrast, in the present embodiment, heat from the first coil ends 55a is transferred to the circumferential wall portion 14 via the second route R2 and the third route R3 in addition to the first route R1. Heat from the second coil ends 55c is transferred to the circumferential wall portion 14 via the fifth route R5 and the sixth route in addition to the fourth route R4. As a result, in the present embodiment, the amount of heat transferred from the coil ends 55 to the circumferential wall portion 14 can be increased, preventing the temperature of the coil ends 55 from becoming too high.

[0057] According to this embodiment, the motor 10 comprises a rotor 40 that can rotate around a central axis J, a stator 50 that is arranged radially outside the rotor 40 and faces the rotor 40 at a radial distance, a cylindrical heat transfer member 30 that surrounds the central axis J, and a housing 11 that accommodates the rotor 40, the stator 50, and the heat transfer member 30. The housing 11 has a cylindrical peripheral wall portion 14 that surrounds the stator 50 from the radially outside, and a protrusion portion 15 that is connected to the peripheral wall portion 14 and protrudes radially inward from the inner surface of the peripheral wall portion 14. The stator 50 has an annular stator core 51 that surrounds the central axis J, and a coil portion 54 that is attached to the stator core 51. The coil portion 54 has a first coil end 55a that protrudes upward from the stator core 51, i.e., to one axial side, and a second coil end 55c that protrudes downward from the stator core 51, i.e., to the other axial side. In the radial direction, at least a portion of the heat transfer member 30 is arranged between the first coil end 55a and the peripheral wall portion 14. The protrusion portion 15 is located below the second coil end 55c and faces the second coil end 55c in the axial direction. Therefore, as described above, the thermal resistance between the insulator 52 and the peripheral wall portion 14 can be reduced in the second path R2 compared to a configuration in which the heat transfer member 30 is not disposed between the first coil ends 55a and the peripheral wall portion 14. This increases the amount of heat transferred from the first coil ends 55a to the peripheral wall portion 14 via the second path R2. This increases the amount of heat radiated from the first coil ends 55a to the outside of the motor 10. This prevents the temperature of the first coil ends 55a from becoming too high. Furthermore, as described above, the protrusion 15 can be positioned closer to the second coil ends 55c, which increases the amount of heat transferred from the second coil ends 55c to the protrusion 15. This increases the amount of heat transferred from the second coil ends 55c to the peripheral wall portion 14 via the sixth path R6. This increases the amount of heat radiated from the second coil ends 55c to the outside of the motor 10. This prevents the temperature of the second coil ends 55c from becoming too high. As a result, the temperature of the coil end 55 can be prevented from becoming too high, and deterioration of the coil portion 54 can be prevented.

[0058] Furthermore, in this embodiment, the heat transfer member 30 and the circumferential wall portion 14 are separate members. Therefore, during the assembly process of the motor 10, the stator 50 is inserted into the circumferential wall portion 14 through the opening 14a of the housing 11, and after the stator 50 is fixed to the inner circumferential surface of the circumferential wall portion 14, the heat transfer member 30 can be inserted into the circumferential wall portion 14 through the opening 14a. This makes it easy to fix the heat transfer member 30 to the circumferential wall portion 14. This prevents an increase in the number of steps required to assemble the motor 10. Furthermore, as described above, the inner circumferential surface of the heat transfer member 30 is located radially inward of the inner circumferential surface of the circumferential wall portion 14. This reduces the thermal resistance between the first coil end 55a and the circumferential wall portion 14 compared to a configuration without the heat transfer member 30. This prevents the temperature of the first coil end 55a from becoming too high. This prevents an increase in the number of steps required to assemble the motor 10 and prevents deterioration of the coil portion 54.

[0059] According to this embodiment, the outer peripheral surface of the heat transfer member 30 contacts the inner peripheral surface of the peripheral wall portion 14. This reduces the thermal resistance between the heat transfer member 30 and the peripheral wall portion 14. This reduces the thermal resistance between the first coil ends 55a and the peripheral wall portion 14 along each of the second path R2 and the third path R3. This increases the amount of heat transferred from the first coil ends 55a to the peripheral wall portion 14 along each of the second path R2 and the third path R3. This more effectively prevents the temperature of the first coil ends 55a from becoming too high.

[0060] According to this embodiment, the stator 50 has an insulator 52 attached to the stator core 51. A portion of the insulator 52 is disposed radially between the heat transfer member 30 and the first coil ends 55 a, and the heat transfer member 30 contacts the insulator 52. Therefore, as described above, the thermal resistance between the insulator 52 and the heat transfer member 30 can be suitably reduced. This can suitably reduce the thermal resistance between the insulator 52 and the peripheral wall portion 14 along the second path R2. This can more suitably increase the amount of heat transferred from the first coil ends 55 a to the peripheral wall portion 14 via the second path R2. This can more suitably prevent the temperature of the first coil ends 55 a from becoming too high.

[0061] According to this embodiment, the radially inner end of the protrusion 15 is located radially inward of the second coil end 55c. Therefore, in this embodiment, the thermal resistance between the radially inner portion of the second coil end 55c and the protrusion 15 can be reduced compared to a configuration in which the radially inner end of the protrusion 15 is located radially outward of the radially inner end of the second coil end 55c. This more effectively reduces the thermal resistance between the second coil end 55c and the peripheral wall 14 along the sixth path R6. This more effectively increases the amount of heat transferred from the second coil end 55c to the peripheral wall 14 via the sixth path R6. This more effectively prevents the temperature of the second coil end 55c from becoming too high.

[0062] According to this embodiment, the motor 10 includes the first resin portion 61 that covers and contacts the first coil ends 55a, and the heat transfer member 30 contacts the first resin portion 61. As described above, this embodiment reduces the thermal resistance between the first coil ends 55a and the heat transfer member 30 along the third path R3 compared to a configuration in which the motor 10 does not include the first resin portion 61. This increases the amount of heat transferred from the first coil ends 55a to the heat transfer member 30 along the third path R3. This increases the amount of heat transferred from the first coil ends 55a to the peripheral wall portion 14 via the third path R3. This more effectively prevents the temperature of the first coil ends 55a from becoming too high.

[0063] According to this embodiment, the thermal conductivity of the heat transfer member 30 is greater than that of the first resin portion 61. Therefore, the thermal resistance between the first coil ends 55a and the peripheral wall portion 14 can be more effectively reduced along each of the second path R2 and the third path R3 compared to when the thermal conductivity of the heat transfer member 30 is smaller than that of the first resin portion 61. This more effectively increases the amount of heat transferred from the first coil ends 55a to the peripheral wall portion 14. This more effectively prevents the temperature of the first coil ends 55a from becoming too high.

[0064] According to this embodiment, the motor 10 includes a second resin portion 62 that covers and contacts the second coil ends 55c, and the protrusions 15 contact the second resin portion 62. Therefore, in this embodiment, the thermal resistance between the second coil ends 55c and the protrusions 15 can be more effectively reduced along the sixth path R6 than in a configuration in which the protrusions 15 do not contact the second resin portion 62. This more effectively reduces the thermal resistance between the second coil ends 55c and the peripheral wall portion 14 along the sixth path R6. This increases the amount of heat transferred from the second coil ends 55c to the peripheral wall portion 14 via the sixth path R6. This more effectively prevents the temperature of the second coil ends 55c from becoming too high.

[0065] According to this embodiment, the thermal conductivity of the protrusion 15 is greater than that of the second resin portion 62. Therefore, the thermal resistance between the second coil end 55c and the peripheral wall portion 14 along the sixth path R6 can be more effectively reduced compared to when the thermal conductivity of the protrusion 15 is less than that of the second resin portion 62. This more effectively increases the amount of heat transferred from the second coil end 55c to the peripheral wall portion 14. This more effectively prevents the temperature of the second coil end 55c from becoming too high.

[0066] According to this embodiment, the motor 10 includes a busbar unit 70 electrically connected to the coil portion 54. The housing 11 has a plate-shaped bottom plate portion 18 extending in a direction intersecting the axial direction. The bottom plate portion 18 is disposed below the protruding portion 15, i.e., on the other axial side, and the busbar unit 70 is disposed axially between the protruding portion 15 and the bottom plate portion 18. Therefore, in this embodiment, it is easier to position the protruding portion 15 closer to the second coil end 55c than in a configuration in which the busbar unit 70 is disposed between the protruding portion 15 and the stator 50. This makes it easier to increase the amount of heat transferred from the second coil end 55c to the peripheral wall portion 14 via the sixth path R6. This makes it easier to prevent the temperature of the second coil end 55c from becoming too high.

[0067] According to this embodiment, the housing 11 has multiple heat dissipation portions 21 that protrude radially outward from the outer peripheral surface of the peripheral wall portion 14. When viewed radially, the first coil ends 55 a and the heat transfer members 30 overlap with the heat dissipation portions 21. This allows the first coil ends 55 a and the heat transfer members 30 to be positioned close to the heat dissipation portions 21, thereby reducing the thermal resistance between the first coil ends 55 a and the heat transfer members 30 and the heat dissipation portions 21. This increases the amount of heat transferred from the first coil ends 55 a to the heat dissipation portions 21. This effectively increases the amount of heat dissipated from the first coil ends 55 a to the outside of the motor 10 via the heat dissipation portions 21. This effectively prevents the temperature of the first coil ends 55 a from becoming too high.

[0068] According to this embodiment, the second coil ends 55c and the protruding portions 15 overlap the heat dissipation portions 21 when viewed radially. This allows the second coil ends 55c and the protruding portions 15 to be positioned close to the heat dissipation portions 21, thereby reducing the thermal resistance between the second coil ends 55c and the protruding portions 15 and the heat dissipation portions 21. This increases the amount of heat transferred from the second coil ends 55c to the heat dissipation portions 21. This effectively increases the amount of heat dissipated from the second coil ends 55c to the outside of the motor 10 via the heat dissipation portions 21. This effectively prevents the temperature of the second coil ends 55c from becoming too high.

[0069] According to this embodiment, the rotor 40 includes an annular magnet holder 41 surrounding the central axis J, an annular magnet 42 fixed to a radially outward surface of the magnet holder 41, and a plurality of plate-shaped blade members 46 extending in a direction intersecting the circumferential direction. The plurality of blade members 46 includes a plurality of first blade members 47 located above the magnet 42, i.e., on one axial side, and spaced apart along the circumferential direction, and a plurality of second blade members 48 located below the magnet 42, i.e., on the other axial side, and spaced apart along the circumferential direction. Thus, as described above, when the rotor 40 rotates about the central axis J, the plurality of first blade members 47 can direct airflow AF1 toward the first coil end 55 a, and the plurality of second blade members 48 can direct airflow AF2 toward the second coil end 55 c. This allows the first coil end 55 a and the second coil end 55 c to be cooled, thereby more effectively preventing the temperature of the coil end 55 from becoming too high.

[0070] 6, a motor 210 of the present embodiment includes a heat transfer member 230 and a resin portion 260. In the following description, the same components as those in the first embodiment are denoted by the same reference numerals, and the description thereof will be omitted.

[0071] The heat transfer member 230 transfers heat generated in the first coil end 55a to the peripheral wall portion 14. As shown in FIG. 7 , in this embodiment, the heat transfer member 230 has a first heat transfer portion 230a and a second heat transfer portion 230c. The first heat transfer portion 230a has a cylindrical shape surrounding the central axis J. More specifically, the first heat transfer portion 230a has a substantially cylindrical shape centered on the central axis J. The first heat transfer portion 230a extends in the axial direction. The downward surface of the first heat transfer portion 230a is in axial contact with the stator core 51. In the radial direction, the first heat transfer portion 230a is disposed between the insulator 52 and the peripheral wall portion 14. The first heat transfer portion 230a is disposed between the peripheral wall portion 14 and the first coil end 55a. The inner circumferential surface of the first heat transfer portion 230a is located radially inward of the inner circumferential surface of the peripheral wall portion 14. The first heat transfer portion 230a contacts the insulator 52. The outer circumferential surface of the first heat transfer portion 230a contacts the inner circumferential surface of the peripheral wall portion 14. In this embodiment, the first heat transfer portion 230a is press-fitted and fixed to the peripheral wall portion 14. In this way, the heat transfer member 230 is fixed to the housing 11.

[0072] The second heat transfer portion 230c protrudes radially inward from the first heat transfer portion 230a. More specifically, the second heat transfer portion 230c protrudes radially inward from the upper end of the first heat transfer portion 230a. The second heat transfer portion 230c is connected to the first heat transfer portion 230a. The first heat transfer portion 230a and the second heat transfer portion 230c are part of a single member. The second heat transfer portion 230c has a generally annular plate shape centered on the central axis J. The plate surface of the second heat transfer portion 230c faces the axial direction. The second heat transfer portion 230c is located above the first coil end 55a, i.e., on one axial side. The radially inner end of the second heat transfer portion 230c is located radially inward from the first coil end 55a. The second heat transfer portion 230c faces the first coil end 55a in the axial direction. Other configurations of the heat transfer member 230 of this embodiment are similar to other configurations of the heat transfer member 30 of the first embodiment described above.

[0073] 6 , the resin part 260 is in contact with each of the coil end 55, the heat transfer member 230, and the housing 11. In the present embodiment, the resin part 260 has a first resin part 261 and a second resin part 62. That is, the motor 210 includes the first resin part 261 and the second resin part 62.

[0074] As shown in FIG. 7 , the first resin portion 261 is filled between the first coil end 55 a and the heat transfer member 230. The first resin portion 261 contacts both the first coil end 55 a and the heat transfer member 230. More specifically, the first resin portion 261 covers the first coil end 55 a from above. This brings the first resin portion 261 into contact with the first coil end 55 a. The first resin portion 261 also comes into contact with the downward surface of the second heat transfer portion 230 c. This brings the heat transfer member 230 into contact with the first resin portion 261. In this embodiment, the thermal conductivity of the heat transfer member 230 is greater than the thermal conductivity of the first resin portion 261. Other configurations of the first resin portion 261 of this embodiment are similar to those of the first resin portion 61 of the first embodiment described above. Other configurations of the resin part 260 of this embodiment are similar to other configurations of the resin part 60 of the first embodiment described above.

[0075] Because the motor 210 of this embodiment includes the heat transfer member 230 and the first resin portion 261 described above, the paths along which heat generated in the first coil ends 55 a is transferred to the peripheral wall portion 14 include the first path R1, the second path R2, and the third path R23. In each of the first path R1 and the second path R2 of this embodiment, the amount of heat transferred from the first coil ends 55 a to the peripheral wall portion 14 is similar to the amount of heat transferred from the first coil ends 55 a to the peripheral wall portion 14 in each of the first path R1 and the second path R2 of the first embodiment described above.

[0076] The third path R23 is a path through which heat generated in the first coil ends 55a is transferred to the peripheral wall portion 14 via the first resin portion 261 and the heat transfer member 230. In this embodiment, as described above, the second heat transfer portion 230c axially faces the first coil ends 55a, allowing the second heat transfer portion 230c to be positioned closer to the first coil ends 55a. This more effectively reduces the thermal resistance between the first coil ends 55a and the heat transfer member 230. Therefore, the third path R23 effectively reduces the thermal resistance between the first coil ends 55a and the peripheral wall portion 14. The other configurations of the motor 210 of this embodiment are similar to those of the motor 10 of the first embodiment described above.

[0077] According to this embodiment, the heat transfer member 230 includes a cylindrical first heat transfer portion 230a that surrounds the central axis J and extends in the axial direction, and a second heat transfer portion 230c that protrudes radially inward from the first heat transfer portion 230a. In the radial direction, the first heat transfer portion 230a is disposed between the peripheral wall portion 14 and the first coil ends 55a, while the second heat transfer portion 230c is located above the first coil ends 55a, i.e., on one axial side, and axially opposite the first coil ends 55a. Therefore, as described above, the second heat transfer portion 230c can be disposed close to the first coil ends 55a, which effectively reduces the thermal resistance between the first coil ends 55a and the peripheral wall portion 14 along the third path R23. This effectively increases the amount of heat transferred from the first coil ends 55a to the peripheral wall portion 14 via the third path R23. Therefore, the temperature of the first coil end 55a can be prevented from becoming too high. Therefore, the temperature of the coil end 55 can be prevented from becoming too high, and deterioration of the coil portion 54 can be prevented.

[0078] In addition, in this embodiment, the first heat transfer portion 230a and the second heat transfer portion 230c are part of a single member. Therefore, compared to when the first heat transfer portion 230a and the second heat transfer portion 230c are separate members, an increase in the number of parts in the motor 210 can be suppressed. Therefore, an increase in the manufacturing cost and manufacturing man-hours for the motor 210 can be suppressed.

[0079] 8, a motor 310 of the present embodiment includes a heat transfer member 330 and a resin portion 360. In the following description, the same components as those in the first embodiment are denoted by the same reference numerals, and description thereof will be omitted.

[0080] The heat transfer member 330 transfers heat generated in the first coil ends 55a to the circumferential wall portion 14. The heat transfer member 330 has a cylindrical shape surrounding the central axis J. More specifically, the heat transfer member 330 has a substantially cylindrical shape centered on the central axis J. As shown in FIG. 9 , the downward surface of the heat transfer member 330 contacts the stator core 51 in the axial direction. In the radial direction, the heat transfer member 330 is disposed between the insulator 52 and the circumferential wall portion 14. In the radial direction, at least a portion of the heat transfer member 330 is disposed between the first coil ends 55a and the circumferential wall portion 14. The inner circumferential surface of the heat transfer member 330 is located radially inward of the inner circumferential surface of the circumferential wall portion 14. The heat transfer member 330 contacts the insulator 52. The outer circumferential surface of the heat transfer member 330 contacts the inner circumferential surface of the circumferential wall portion 14. The heat transfer member 330 is press-fitted and fixed to the peripheral wall portion 14. In this embodiment, the upper end of the heat transfer member 330, i.e., the end on one axial side, is connected to the cover member 16. In this embodiment, the heat transfer member 330 and the cover member 16 are part of a single member. As in the first embodiment described above, the cover member 16 closes the opening 14a of the peripheral wall portion 14 from above, i.e., from one axial side. Other configurations of the heat transfer member 330 of this embodiment are similar to those of the heat transfer member 330 of the first embodiment described above.

[0081] 8 , the resin part 360 is in contact with each of the coil end 55, the heat transfer member 330, and the housing 11. In the present embodiment, the resin part 360 has a first resin part 361 and a second resin part 62. That is, the motor 210 includes the first resin part 361 and the second resin part 62.

[0082] As shown in FIG. 9 , the first resin portion 361 is filled between the first coil end 55 a and the heat transfer member 330. The first resin portion 361 contacts both the first coil end 55 a and the heat transfer member 330. More specifically, the first resin portion 361 covers the first coil end 55 a from above. This brings the first resin portion 361 into contact with the first coil end 55 a. The first resin portion 361 contacts the surface of the heat transfer member 330 facing radially inward. This brings the heat transfer member 330 into contact with the first resin portion 361. In this embodiment, the thermal conductivity of the heat transfer member 330 is greater than the thermal conductivity of the first resin portion 361. Other configurations of the first resin portion 361 of this embodiment are similar to those of the first resin portion 61 of the first embodiment described above. Other configurations of the resin part 360 of this embodiment are similar to other configurations of the resin part 60 of the first embodiment described above.

[0083] Because the motor 310 of this embodiment includes the heat transfer member 330 and the first resin portion 361 described above, the paths along which heat generated in the first coil ends 55 a is transferred to the peripheral wall portion 14 include the first path R1, the second path R2, and the third path R3. In this embodiment, the thermal resistance between the insulator 52 and the peripheral wall portion 14 can be reduced in the second path R2 compared to a configuration in which the heat transfer member 330 is not disposed between the first coil ends 55 a and the peripheral wall portion 14. As a result, in this embodiment, the amount of heat transferred from the first coil ends 55 a to the peripheral wall portion 14 via the second path R2 can be increased. The other configurations of the motor 310 of this embodiment are similar to those of the motor 10 of the first embodiment described above.

[0084] According to this embodiment, the peripheral wall 14 has an opening 14a on the upper side, i.e., on one axial side, the housing 11 has a cover member 16 that closes the opening 14a from above, and the upper end of the heat transfer member 330 is connected to the cover member 16. Therefore, as described above, the heat transfer member 330 and the cover member 16 are part of a single member, which prevents an increase in the number of parts of the motor 310 compared to a configuration in which the heat transfer member 330 and the cover member 16 are separate components. This prevents an increase in the manufacturing cost of the motor 310.

[0085] Furthermore, in this embodiment, as described above, the heat transfer member 330 is part of the cover member 16, and therefore, in the assembly process of the motor 10, the heat transfer member 330 can be disposed between the first coil end 55a and the peripheral wall portion 14 by simply fastening the cover member 16 to the peripheral wall portion 14. Therefore, an increase in the number of steps required to assemble the motor 310 can be suppressed.

[0086] Furthermore, in this embodiment, as described above, at least a portion of the heat transfer member 330 is disposed radially between the first coil ends 55a and the circumferential wall portion 14. Therefore, as described above, in this embodiment, the amount of heat transferred from the first coil ends 55a to the circumferential wall portion 14 via the second path R2 can be increased compared to a configuration in which the heat transfer member 330 is not disposed between the first coil ends 55a and the circumferential wall portion 14. This increases the amount of heat dissipated from the first coil ends 55a to the outside of the motor 310. This prevents the temperature of the first coil ends 55a from becoming too high. This effectively prevents the temperature of the coil ends 55 from becoming too high, thereby effectively preventing deterioration of the coil portion 54.

[0087] The present invention is not limited to the above-described embodiment, and other configurations and methods may be adopted within the scope of the technical concept of the present invention. For example, the resin portion may not include one of the first resin portion and the second resin portion. Furthermore, the rotor may not include multiple blade members.

[0088] The thermal conductivity of the heat transfer member may be lower than that of the first resin portion, and in this case, the amount of heat transferred from the first coil end to the peripheral wall portion can be increased compared to a motor configured without a heat transfer member.

[0089] The housing does not need to have a heat dissipation portion. Even in this case, the heat transfer member, protrusions, and resin portion can reduce the thermal resistance between the coil ends and the peripheral wall, thereby increasing the amount of heat transferred from the coil ends to the peripheral wall. This increases the amount of heat dissipated from the coil ends to the outside of the motor.

[0090] Although the embodiments of the present invention have been described above, the configurations and combinations thereof in the embodiments are merely examples, and additions, omissions, substitutions, and other modifications of the configurations are possible without departing from the spirit of the present invention. Furthermore, the present invention is not limited to the embodiments.

[0091] The present technology can be configured as follows. (1) A motor including: a rotor rotatable about a central axis; a stator disposed radially outward of the rotor and facing the rotor with a radial gap therebetween; a cylindrical heat transfer member surrounding the central axis; and a housing accommodating the rotor, the stator, and the heat transfer member, wherein the housing has a cylindrical peripheral wall portion surrounding the stator from the radially outer side and a protrusion portion connected to the peripheral wall portion and protruding radially inward from an inner peripheral surface of the peripheral wall portion, the stator having an annular stator core surrounding the central axis and a coil portion attached to the stator core, the coil portion having a first coil end protruding from the stator core to one axial side and a second coil end protruding from the stator core to the other axial side, at least a portion of the heat transfer member being disposed radially between the first coil end and the peripheral wall portion, and the protrusion portion being located on the other axial side of the second coil end and facing the second coil end in the axial direction. (2) The motor according to (1), wherein an outer peripheral surface of the heat transfer member contacts an inner peripheral surface of the circumferential wall portion. (3) The motor according to (1) or (2), wherein the stator has an insulator attached to the stator core, a portion of the insulator is disposed radially between the heat transfer member and the first coil end, and the heat transfer member contacts the insulator. (4) The motor according to any one of (1) to (3), wherein the heat transfer member has a cylindrical first heat transfer portion that surrounds the central axis and extends in the axial direction, and a second heat transfer portion that protrudes radially inward from the first heat transfer portion, the first heat transfer portion is disposed radially between the circumferential wall portion and the first coil end, and the second heat transfer portion is located on one axial side of the first coil end and faces the first coil end in the axial direction. (5) The motor according to any one of (1) to (4), wherein the peripheral wall portion has an opening that opens to one axial side, the housing has a cover member that closes the opening from the one axial side, and an end of the heat transfer member on the one axial side is connected to the cover member. (6) The motor according to any one of (1) to (5), wherein a radially inner end of the protrusion is located radially inner than the second coil end.(7) The motor according to any one of (1) to (6), including a first resin portion covering the first coil ends and in contact with the first coil ends, and the heat transfer member contacting the first resin portion. (8) The motor according to (7), including a thermal conductivity of the heat transfer member greater than that of the first resin portion. (9) The motor according to any one of (1) to (8), including a second resin portion covering the second coil ends and in contact with the second coil ends, and the protruding portion contacting the second resin portion. (10) The motor according to (9), including a thermal conductivity of the protruding portion greater than that of the second resin portion. (11) The motor according to any one of (1) to (10), including a busbar unit electrically connected to the coil portion, the housing having a bottom plate portion extending in a direction intersecting the axial direction, the bottom plate portion being positioned on the other axial side of the protruding portion, and the busbar unit being positioned axially between the protruding portion and the bottom plate portion. (12) The motor according to any one of (1) to (11), wherein the housing has a plurality of heat dissipation portions protruding radially outward from an outer circumferential surface of the peripheral wall portion, and the first coil ends and the heat transfer members overlap with the heat dissipation portions when viewed from the radial direction. (13) The motor according to (12), wherein the second coil ends and the protruding portions overlap with the heat dissipation portions when viewed from the radial direction. (14) The motor according to any one of (1) to (13), wherein an inner circumferential surface of the peripheral wall portion is provided with a stepped surface facing one axial side, and a surface of the stator core facing the other axial side is in axial contact with the stepped surface. (15) The motor described in any one of (1) to (14), wherein the rotor has an annular magnet holding portion surrounding the central axis, an annular magnet fixed to a surface of the magnet holding portion facing radially outward, and a plurality of blade members that are plate-shaped and extend in a direction intersecting the circumferential direction, and the plurality of blade members include a plurality of first blade members located on one axial side of the magnet and spaced apart along the circumferential direction, and a plurality of second blade members located on the other axial side of the magnet and spaced apart along the circumferential direction.

[0092] DESCRIPTION OF SYMBOLS 10, 210, 310...motor, 11...housing, 14...peripheral wall portion, 14a...opening, 14e...step surface, 15...protrusion, 16...lid member, 18...bottom plate portion, 21...heat dissipation portion, 30, 230, 330...heat transfer member, 40...rotor, 41...magnet holding portion, 42...magnet, 46...blade member, 47...first blade member, 48...second blade member, 50...stator, 51...stator core, 52...insulator, 54...coil portion, 55a...first coil end, 55c...second coil end, 61, 261, 361...first resin portion, 62...second resin portion, 70...busbar unit, 230a...first heat transfer portion, 230c...second heat transfer portion, J...central axis

Claims

1. A motor comprising: a rotor rotatable about a central axis; a stator arranged radially outward of the rotor and facing the rotor with a radial gap therebetween; a cylindrical heat transfer member surrounding the central axis; and a housing accommodating the rotor, the stator, and the heat transfer member, wherein the housing has: a cylindrical peripheral wall portion surrounding the stator from the radially outer side; and a protrusion portion connected to the peripheral wall portion and protruding radially inward from an inner peripheral surface of the peripheral wall portion, wherein the stator has an annular stator core surrounding the central axis and a coil portion attached to the stator core, wherein the coil portion has a first coil end protruding from the stator core to one axial side and a second coil end protruding from the stator core to the other axial side, wherein at least a portion of the heat transfer member is arranged radially between the first coil end and the peripheral wall portion, and the protrusion portion is located on the other axial side of the second coil end and faces the second coil end in the axial direction.

2. The motor according to claim 1, wherein the outer peripheral surface of the heat transfer member contacts the inner peripheral surface of the peripheral wall portion.

3. The motor according to claim 1, wherein the stator has an insulator attached to the stator core, a portion of the insulator is disposed radially between the heat transfer member and the first coil end, and the heat transfer member is in contact with the insulator.

4. The motor described in claim 1, wherein the heat transfer member has a cylindrical first heat transfer portion that surrounds the central axis and extends in the axial direction, and a second heat transfer portion that protrudes radially inward from the first heat transfer portion, the first heat transfer portion being disposed radially between the peripheral wall portion and the first coil end, and the second heat transfer portion being located on one axial side of the first coil end and facing the first coil end in the axial direction.

5. The motor according to claim 1, wherein the peripheral wall portion has an opening that opens to one axial side, the housing has a cover member that closes the opening from one axial side, and an end of the heat transfer member on one axial side is connected to the cover member.

6. The motor according to claim 1, wherein a radially inner end of the protrusion is located radially inward of the second coil end.

7. A motor according to any one of claims 1 to 6, further comprising a first resin portion that covers the first coil end and is in contact with the first coil end, and the heat transfer member is in contact with the first resin portion.

8. The motor according to claim 7, wherein the thermal conductivity of the heat transfer member is greater than the thermal conductivity of the first resin portion.

9. The motor according to any one of claims 1 to 6, further comprising a second resin portion that covers the second coil end and is in contact with the second coil end, and the protrusion is in contact with the second resin portion.

10. The motor according to claim 9, wherein the thermal conductivity of the protrusion is greater than the thermal conductivity of the second resin portion.

11. The motor according to any one of claims 1 to 6, further comprising a busbar unit electrically connected to the coil portion, wherein the housing has a bottom plate portion extending in a direction intersecting the axial direction, the bottom plate portion being positioned on the other axial side of the protruding portion, and the busbar unit being positioned axially between the protruding portion and the bottom plate portion.

12. A motor as claimed in any one of claims 1 to 6, wherein the housing has a plurality of heat dissipation portions that protrude radially outward from the outer peripheral surface of the peripheral wall portion, and when viewed radially, the first coil end and the heat transfer member each overlap with the heat dissipation portion.

13. The motor according to claim 12, wherein, when viewed in the radial direction, the second coil end and the protruding portion each overlap the heat dissipation portion.

14. A motor as claimed in any one of claims 1 to 6, wherein the inner peripheral surface of the peripheral wall portion is provided with a stepped surface facing one axial side, and the surface of the stator core facing the other axial side is in axial contact with the stepped surface.

15. A motor as described in any one of claims 1 to 6, wherein the rotor has an annular magnet holding portion surrounding the central axis, an annular magnet fixed to a surface facing radially outward of the magnet holding portion, and a plurality of plate-shaped blade members extending in a direction intersecting the circumferential direction, the plurality of blade members including: a plurality of first blade members located on one axial side of the magnet and arranged at intervals along the circumferential direction, and a plurality of second blade members located on the other axial side of the magnet and arranged at intervals along the circumferential direction.

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