Motor and flying body

Abstract

A motor according to the present invention comprises: a rotor that is rotatable about a central axis; a stator that faces the rotor with a gap therebetween; and a housing that houses the rotor and the stator. The housing has a housing body portion that surrounds the stator, and a plurality of heat dissipation portions that protrude from an outer surface of the housing body portion to the outside of the housing body portion and extend in a first direction. The plurality of heat dissipation portions include a plurality of first heat dissipation portions and a plurality of second heat dissipation portions. End portions, of the plurality of second heat dissipation portions, on one side in the first direction are located closer to the one side in the first direction than the plurality of first heat dissipation portions. In a second direction intersecting both the first direction and the direction in which the plurality of heat dissipation portions protrude, each of the plurality of first heat dissipation portions is disposed at a position offset from each of the plurality of second heat dissipation portions.

Description

Motor and flying vehicle

[0001] This application claims priority to Japanese Patent Application No. 2024-104144, filed on June 27, 2024, the contents of which are incorporated herein by reference.

[0002] A rotating electric machine is known that includes a motor having a stator and a device casing that houses the motor, and that increases the amount of heat dissipated from the motor to the outside of the device casing by heat dissipation fins provided on the outer surface of the device casing (for example, Patent Document 1).

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

[0004] When the rotating electrical machine described in Patent Document 1 is attached to an apparatus such as an aircraft, if components for attaching the rotating electrical machine to the apparatus are placed near the heat dissipation fins, there is a risk that such components will obstruct the flow of air between some of the heat dissipation fins. In this case, the amount of heat dissipated from the heat dissipation fins to the outside of the apparatus casing will decrease, and there is a risk that the temperature of some parts of the motor will become too high.

[0005] In view of the above circumstances, one aspect of the present invention aims to provide a motor and an aircraft that can prevent the temperature of part of the stator from becoming too high.

[0006] One aspect of the motor of the present invention includes a rotor rotatable about a central axis, a stator facing the rotor at a distance, and a housing that accommodates the rotor and the stator. The housing has a housing main body that surrounds the stator and a plurality of heat dissipation portions that protrude from an outer surface of the housing main body to the outside of the housing main body and extend in a first direction. The plurality of heat dissipation portions include a plurality of first heat dissipation portions and a plurality of second heat dissipation portions. Ends of the plurality of second heat dissipation portions on one side in the first direction are located on one side in the first direction relative to the plurality of first heat dissipation portions. In a second direction that intersects both the direction in which the plurality of heat dissipation portions protrude and the first direction, each of the plurality of first heat dissipation portions is positioned offset from each of the plurality of second heat dissipation portions.

[0007] One aspect of the flying vehicle of the present invention includes a motor and a rotor connected to the motor.

[0008] According to one aspect of the present invention, it is possible to prevent the temperature of a part of the stator in a motor and an aircraft from becoming too high.

[0009] FIG. 1 is a perspective view showing an aircraft of the first embodiment. FIG. 2 is a cross-sectional view showing a motor of the first embodiment. FIG. 3 is a cross-sectional view showing the motor of the first embodiment, taken along III-III in FIG. 2. FIG. 4 is a first plan view of the heat dissipation section of the first embodiment as seen from the radially outer side. FIG. 5 is a second plan view of the heat dissipation section of the first embodiment as seen from the radially outer side. FIG. 6 is a cross-sectional view of a motor of the second embodiment. FIG. 7 is a first plan view of the heat dissipation section of the second embodiment as seen from the radially outer side. FIG. 8 is a second plan view of the heat dissipation section of the second embodiment as seen from the radially outer side.

[0010] Hereinafter, motors and aircraft 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.

[0011] In the following description, a central axis J is shown in each drawing where appropriate. The central axis J shown in each drawing is a virtual axis. In the following description, the direction in which the central axis J extends may be referred to as the "axial direction." The radial direction centered on the central axis J may be simply referred to as the "radial direction." The circumferential direction centered on the central axis J may be simply referred to as the "circumferential direction." The circumferential direction is indicated by an arrow θ in each drawing.

[0012] In the following description, a first direction D1 is indicated in each figure as appropriate. The first direction D1 is the direction in which the heat dissipation unit in the embodiment described below extends. In the embodiment described below, the first direction D1 is parallel to the axial direction. In the following description, the side of the first direction D1 toward which the arrow points (the +D1 side) is referred to as "one side of the first direction D1" or "upper side." The side of the first direction D1 opposite to the side toward which the arrow points (the -D1 side) is referred to as "the other side of the first direction D1" or "lower 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.

[0013] In the following description, the second direction D2 is appropriately shown in each figure. The second direction D2 is a direction that intersects both the direction in which the heat dissipation portion protrudes and the first direction D1 in the embodiment described below. In this embodiment, the second direction D2 is a direction that is perpendicular to both the direction in which the heat dissipation portion protrudes and the first direction D1. The second direction D2 does not have to be perpendicular to at least one of the direction in which the heat dissipation portion protrudes and the first direction D1. In this embodiment, the second direction D2 is parallel to the circumferential direction. In the following description, the side of the second direction D2 toward which the arrow points (the +D2 side) will be referred to as "one side of the second direction D2." The side of the second direction D2 opposite to the side toward which the arrow points (the -D2 side) will be referred to as "the other side of the second direction D2."

[0014] First Embodiment As shown in FIG. 1 , the aircraft 90 of this embodiment is an unmanned aircraft including a main body 91, a frame 92, rotors 93, and a motor 10. The aircraft 90 may also be a manned aircraft. The main body 91 extends in a direction perpendicular to the axial direction. The frame 92 is fixed to the main body 91. The frame 92 holds the motor 10. The frame 92 is frame-shaped and surrounds the rotors 93 and the motor 10 from the radially outer side. More specifically, the frame 92 is substantially annular and centered on the central axis J. In this embodiment, the aircraft 90 has four frame parts 92. Each frame part 92 is arranged circumferentially around the main body 91. Each frame part 92 is provided, for example, to protect the rotors 93 and to appropriately guide the airflow generated by the rotors 93 along the inner circumferential surface of the frame part 92. In this embodiment, the frame portion 92 has a substantially annular shape, which makes it easy to achieve these functions. In this embodiment, each frame portion 92 is a single member together with the main body portion 91. The main body portion 91 and the frame portion 92 may be made of a resin such as polystyrene foam. The main body portion 91 and the frame portion 92 may also be made of metal. Furthermore, each frame portion 92 and the main body portion 91 may be made of different members.

[0015] The motors 10 rotate the rotors 93 around the central axis J. In this embodiment, the flying object 90 is equipped with four motors 10. Each motor 10 is housed inside a different frame 92 and attached to the frame 92. The motors 10 are supplied with current from a power source (not shown). In this embodiment, the power source is a rechargeable battery. The configuration of the motors 10 in this embodiment will be described in detail later.

[0016] The rotors 93 are connected to the motor 10. More specifically, the rotors 93 are connected to a shaft included in the motor 10. In this embodiment, the flying object 90 has four rotors 93. Each rotor 93 is housed inside a different frame 92. Each rotor 93 is connected to a different motor 10. Each rotor 93 has a shaft 93a and a blade 93b.

[0017] The shaft portion 93a has a generally cylindrical shape extending in the axial direction around the central axis J. Although not shown, the shaft portion 93a is connected to a shaft provided in the motor 10. The blade portions 93b protrude radially outward from the shaft portion. In this embodiment, each rotor 93 has two blade portions 93b. The blade portions 93b face each other in the radial direction, sandwiching the shaft portion 93a therebetween. The motor 10 rotates the shaft to rotate the rotor 93 around the central axis J. As the rotor 93 rotates around the central axis J, the flying object 90 obtains buoyancy and propulsion in a direction intersecting the vertical direction.

[0018] As shown in FIG. 2 , the motor 10 of this embodiment is a disk-shaped motor centered on a central axis J. The motor 10 of this embodiment is a drive device that rotates a rotor 93 provided on an aircraft 90 about the central axis J. The motor 10 is a thin motor whose axial dimension is smaller than its radial dimension. The motor 10 is a radial gap motor in which the stator 50 faces the rotor 40 at a radial distance. The motor 10 may also be an axial gap motor in which the stator 50 faces the rotor 40 at an axial distance. The motor 10 includes a housing 11, a rotor 40, a shaft 44, and a stator 50.

[0019] The housing 11 has a generally cylindrical shape extending in the axial direction about a central axis J. The housing 11 accommodates the rotor 40 and the stator 50 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 first housing 13, a second housing 16, a housing main body 12, a heat dissipation section 30, and a top plate heat dissipation section 34.

[0020] The first housing 13 is the lower portion of the housing 11. The first housing 13 is generally cylindrical and protrudes in the axial direction about a central axis J. The first housing 13 is open at the top. The first housing 13 has a first peripheral wall portion 14 and a bottom plate portion 15.

[0021] The first circumferential wall portion 14 has a generally cylindrical shape that protrudes in the axial direction about the central axis J. The first circumferential wall portion 14 surrounds a lower portion of the rotor 40 and a lower portion of the stator 50 from the radially outer side.

[0022] The bottom plate portion 15 has a generally annular plate shape centered on the central axis J. The plate surface of the bottom plate portion 15 faces the axial direction. The radial outer edge of the bottom plate portion 15 is connected to the lower end of the first peripheral wall portion 14. The bottom plate portion 15 is disposed below the rotor 40 and the stator 50. The bottom plate portion 15 is provided with a bottom plate hole portion 15a.

[0023] The bottom plate hole 15a is a hole that penetrates the bottom plate 15 in the axial direction. When viewed in the axial direction, the bottom plate hole 15a has a substantially circular shape centered on the central axis J. A second bearing 76 is attached to the inner circumferential surface of the bottom plate hole 15a. The second bearing 76 has a substantially annular shape centered on the central axis J.

[0024] The second housing 16 is the upper portion of the housing 11. The second housing 16 is generally cylindrical and protrudes axially about the central axis J. The second housing 16 is open downward. The second housing 16 is fixed to the upper end of the first housing 13. The second housing 16 has a second peripheral wall portion 17 and a top plate portion 18.

[0025] The second circumferential wall portion 17 has a generally cylindrical shape that protrudes in the axial direction about the central axis J. The second circumferential wall portion 17 surrounds the upper portion of the rotor 40 and the upper portion of the stator 50 from the radially outer side. The lower end of the second circumferential wall portion 17 contacts the upper end of the first circumferential wall portion 14 in the axial direction. The second circumferential wall portion 17 is fixed to the first circumferential wall portion 14. This fixes the second housing 16 to the first housing 13. The second housing 16 may be fixed to the first housing 13 by fastening members such as bolts (not shown), or may be adhesively fixed to the first housing 13 by adhesive.

[0026] The top plate portion 18 has a generally annular plate shape centered on the central axis J. The plate surface of the top plate portion 18 faces the axial direction. The top plate portion 18 is disposed above the stator 50 and the rotor 40. The top plate portion 18 is provided with a top plate recess 18a and a top plate hole 18c.

[0027] The top plate recess 18a is a recess recessed downward from the surface facing upward of the top plate 18. When viewed in the axial direction, the top plate recess 18a has a substantially circular shape centered on the central axis J. A first bearing 75 is attached to the inner peripheral surface of the top plate recess 18a. The first bearing 75 has a substantially annular shape centered on the central axis J.

[0028] The top plate hole 18c is a hole that axially penetrates the top plate 18. When viewed from the axial direction, the top plate hole 18c has a substantially circular shape centered on the central axis J. The top plate hole 18c is provided radially inward of the top plate recess 18a.

[0029] The housing main body 12 is a portion of the housing 11 that surrounds the stator 50. In this embodiment, the housing main body 12 is composed of a first circumferential wall 14, a second circumferential wall 17, a top plate 18, and a bottom plate 15. The housing main body 12 has a cylindrical portion 12a. In this embodiment, the cylindrical portion 12a is composed of the first circumferential wall 14 and the second circumferential wall 17. The cylindrical portion 12a has a substantially cylindrical shape that extends in the axial direction about the central axis J. The cylindrical portion 12a surrounds the rotor 40 and the stator 50 from the radially outer side. The cylindrical portion 12a faces the stator 50 in the radial direction.

[0030] As shown in FIG. 3 , the heat dissipation portion 30 protrudes from the outer surface of the housing main body 12 to the outside of the housing main body 12. More specifically, the heat dissipation portion 30 protrudes radially outward from the surface of the cylindrical portion 12a facing radially outward. As shown in FIG. 4 , in this embodiment, the heat dissipation portion 30 extends axially, i.e., in the first direction D1. The heat dissipation portion 30 is plate-shaped with its plate surface facing circumferentially, i.e., in the second direction D2. In this embodiment, the housing 11 has multiple heat dissipation portions 30. The heat dissipation portions 30 are spaced apart from one another along the second direction D2. This increases the surface area of ​​the outer surface of the housing 11, thereby increasing the amount of heat dissipated from the stator 50 to the outside of the motor 10 via the housing 11. More specifically, the amount of heat dissipated from the stator 50 to the outside of the motor 10 via the cylindrical portion 12a and the heat dissipation portion 30 can be increased. The plurality of heat dissipation portions 30 include a plurality of first heat dissipation portions 31 and a plurality of second heat dissipation portions 33. The heat dissipation portions 30 may be plate-shaped extending in the circumferential direction. In this case, the heat dissipation portions 30 are arranged at intervals from one another in the axial direction. Therefore, in this case, the first direction D1 is the circumferential direction, and the second direction D2 is the axial direction.

[0031] As shown in FIG. 2 , the first heat dissipation portion 31 is a plate-like member that protrudes radially outward from the surface of the cylindrical portion 12 a that faces radially outward. As shown in FIG. 4 , each first heat dissipation portion 31 extends in the axial direction. In the axial direction, the lower end of each first heat dissipation portion 31 is located at the same position as the lower end of the cylindrical portion 12 a. In the axial direction, the upper end of each first heat dissipation portion 31 is located lower than the upper end of the cylindrical portion 12 a. The first heat dissipation portions 31 are arranged at intervals from each other along the second direction D2. Each first heat dissipation portion 31 is composed of a first portion 31 a and a second portion 31 c. Each of the multiple first heat dissipation portions 31 has a first surface 32 a and a second surface 32 c.

[0032] The first portion 31a is a lower portion of the first heat dissipation portion 31. Each first portion 31a protrudes radially outward from the surface of the cylindrical portion 12a that faces radially outward of the first circumferential wall portion 14. Each first portion 31a extends in the axial direction. In the axial direction, the upper end of each first portion 31a is at the same position as the upper end of the first circumferential wall portion 14. The first portions 31a are arranged at intervals from one another along the second direction D2.

[0033] The second portions 31c are upper portions of the first heat dissipation portion 31. Each second portion 31c protrudes radially outward from a surface of the cylindrical portion 12a facing radially outward of the second circumferential wall portion 17. Each second portion 31c extends in the axial direction. In the axial direction, the upper end of each second portion 31c is located lower than the upper end of the second circumferential wall portion 17. In the axial direction, the lower end of each second portion 31c is located at the same position as the lower end of the second circumferential wall portion 17. When viewed in the axial direction, each second portion 31c overlaps with a different first portion 31a. In this embodiment, the lower end of each second portion 31c contacts the upper end of the first portion 31a. The lower end of each second portion 31c may be axially separated from the upper end of the first portion 31a in the first direction D1.

[0034] The first surface 32a is a surface of the outer surface of the first heat dissipation section 31 facing one side (+D2 side) in the second direction D2. The second surface 32c is a surface of the outer surface of the first heat dissipation section 31 facing the other side (-D2 side) in the second direction D2. The upper side of the first surface 32a, i.e., the portion on one side (+D1 side) in the first direction D1, is an inclined surface that is positioned on the other side in the second direction D2 as it extends upward. The upper portion of the second surface 32c is an inclined surface that is positioned on one side in the second direction D2 as it extends upward. As a result, the upper portion of each first heat dissipation section 31 has a shape that is pointed upward when viewed in the radial direction.

[0035] As shown in Fig. 2, the second heat dissipation portions 33 are plate-shaped and protrude radially outward from the radially outward surface of the cylindrical portion 12a. As shown in Fig. 4, each second heat dissipation portion 33 extends in the axial direction. In this embodiment, each second heat dissipation portion 33 is located above the first heat dissipation portion 31, i.e., on one side (+D1 side) in the first direction D1. Therefore, in this embodiment, the ends of the multiple first heat dissipation portions 31 on one side in the first direction D1 are located below the multiple second heat dissipation portions 33, i.e., below the ends on the other side (-D1 side) in the first direction D1.

[0036] Therefore, according to this embodiment, the first heat dissipation portions 31 and the second heat dissipation portions 33 can be disposed at positions spaced apart from each other in the first direction D1. This makes it easier to prevent the structure of the mold from becoming complicated when manufacturing the housing 11 by casting, compared to a configuration in which a portion of each first heat dissipation portion 31 overlaps a portion of each second heat dissipation portion 33 when viewed from the radial direction. This therefore prevents an increase in the number of steps and manufacturing costs for the housing 11.

[0037] The upper sides of the second heat dissipation portions 33, i.e., the ends on one side (+D1 side) in the first direction D1, are located above the first heat dissipation portions 31. In the axial direction, the upper end of each second heat dissipation portion 33 is located above the upper end of the cylindrical portion 12a. In other words, the ends on one side of the second heat dissipation portions 33 in the first direction D1 are located above the housing main body 12. The second heat dissipation portions 33 are spaced apart from one another along the second direction D2. As viewed from the first direction D1, the second heat dissipation portions 33 are located in positions that do not overlap with the first heat dissipation portions 31. In other words, in the second direction D2, each of the first heat dissipation portions 31 is located at a position offset from each of the second heat dissipation portions 33. In this embodiment, the first heat dissipation portions 31 and the second heat dissipation portions 33 are alternately arranged in the second direction D2. In the second direction D2, the first heat dissipation portions 31 and the second heat dissipation portions 33 do not have to be arranged alternately.

[0038] In this embodiment, the dimension W2 in the second direction D2 of each second heat dissipation portion 33 is smaller than the dimension W1 in the second direction D2 of each first heat dissipation portion 31. Note that in this embodiment, the dimension W1 in the second direction D2 of each first heat dissipation portion 31 is the maximum dimension of each first heat dissipation portion 31 in the second direction D2.

[0039] Therefore, according to this embodiment, it is easy to prevent the dimension W2 of the second heat dissipation section 33 in the second direction D2 from increasing, and therefore it is easy to prevent the volume of the second heat dissipation section 33 from increasing. This makes it possible to prevent an increase in the weight of the second heat dissipation section 33. Therefore, it is possible to prevent an increase in the weight of the housing 11 and the motor 10. As a result, it is possible to suitably improve the flight performance of the flying object 90.

[0040] As shown in FIG. 2 , the top plate heat dissipation portion 34 protrudes from the outer surface of the housing main body 12 to the outside of the housing main body 12. More specifically, the top plate heat dissipation portion 34 protrudes upward from the upward-facing surface of the top plate 18. The top plate heat dissipation portion 34 has a plate shape extending in the radial direction. The plate surface of the top plate heat dissipation portion 34 faces the circumferential direction. In this embodiment, the housing 11 has multiple top plate heat dissipation portions 34. The top plate heat dissipation portions 34 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 stator 50 to the outside of the motor 10 via the housing 11. More specifically, the amount of heat dissipated from the stator 50 to the outside of the motor 10 via the top plate 18 and the top plate heat dissipation portions 34 can be increased. In this embodiment, the radially outer end of each top plate heat dissipation portion 34 is connected to the upper end of a different second heat dissipation portion 33. The top plate heat dissipation portion 34 and the second heat dissipation portion 33 do not have to be connected. The radially inner end of each top plate heat dissipation portion 34 is located radially outer than the top plate recess 18a. Note that the housing 11 does not have to have multiple top plate heat dissipation portions 34.

[0041] 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 gap therebetween in the radial direction. The rotor 40 has a magnet holder 41 and a magnet 42.

[0042] The magnet holder 41 has a substantially annular shape centered on the central axis J. In this embodiment, the magnet holder 41 is made of, for example, aluminum. The magnet holder 41 may be made of other materials. The magnet 42 has a substantially annular shape 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.

[0043] The shaft 44 has a generally cylindrical shape extending in the axial direction around the central axis J. The shaft 44 is disposed radially inward of the rotor 40 and the stator 50. The shaft 44 passes axially through the magnet holder 41. The outer peripheral surface of the shaft 44 is fixed to the inner peripheral 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 top plate hole 18c. The upper portion of the shaft 44 is supported by the first bearing 75 so as to be rotatable around the central axis J. The lower end of the shaft 44 protrudes outside the housing 11 through the bottom plate hole 15a. The lower portion of the shaft 44 is supported by the second bearing 76 so as to be rotatable around the central axis J.

[0044] Although not shown, a rotor 93 provided on the flying object 90 is fixed to the upper end of the shaft 44. In other words, the rotor 93 is located above the housing 11. When the shaft 44 rotates about the central axis J, the rotor 93 rotates about the central axis J. When the rotor rotates about the central axis J, the flying object 90 can fly. When the rotor 93 rotates about the central axis J, the rotor 93 blows air toward the housing 11. As shown in FIG. 2 , the airflow AF generated by the rotation of the rotor 93 about the central axis J flows from above toward the top plate 18, the heat dissipation unit 30, and the top plate heat dissipation unit 34. As shown in FIG. 4 , the airflow AF flows downward, i.e., in a direction inclined from the other side (-D1 side) of the first direction D1 to the other side (-D2 side) of the second direction D2.

[0045] 2, 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.

[0046] The stator core 51 has a generally circular ring 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. 3 , the stator core 51 has a core back portion 51 a and teeth portions 51 c.

[0047] 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 cylindrical portion 12a. This fixes the stator 50 to the housing 11. 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 substantially equal intervals along the circumferential direction.

[0048] 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.

[0049] 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. 3 , 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. Although not shown, each coil portion 54 is electrically connected to a power supply (not shown) included in the aircraft 90. When a current is supplied to each coil portion 54 from the power supply, each coil portion 54 forms an electromagnet with its magnetic poles facing radially. When a 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.

[0050] The coil end portions 55 are portions of the coil portion 54 that protrude axially from the stator core 51. Therefore, the thermal resistance between the coil end portions 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 end portions 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 end portions 55 is not easily transmitted to the housing 11 via the stator core 51, the temperature of the coil end portions 55 is likely to rise. In this embodiment, the coil end portions 55 have a first coil end 55a and a second coil end 55c.

[0051] The first coil end 55a is the portion of the coil portion 54 that protrudes upward from the stator core 51. The second coil end 55c is the portion of the coil portion 54 that protrudes downward from the stator core 51. When viewed radially, each of the first coil end 55a and the second coil end 55c overlaps the heat dissipation portion 30. That is, when viewed radially, the coil end portion 55 overlaps the heat dissipation portion 30. This makes it easy to position the coil end portion 55 close to the heat dissipation portion 30, thereby making it easy to reduce thermal resistance between the coil end portion 55 and the heat dissipation portion 30. This increases the amount of heat dissipated from the coil end portion 55 to the outside of the motor 10 via the cylindrical portion 12a and the heat dissipation portion 30. This effectively prevents the temperature of the coil end portion 55 from becoming too high.

[0052] Furthermore, when viewed from the radial direction, the first coil end 55a overlaps with both the first heat dissipation portion 31 and the second heat dissipation portion 33. That is, when viewed from the radial direction, the coil end portion 55 overlaps with both the first heat dissipation portion 31 and the second heat dissipation portion 33.

[0053] When viewed from the axial direction, the first coil end 55a overlaps the top plate heat dissipation portion 34. The first coil end 55a faces the top plate 18 in the axial direction. This makes it easy to position the first coil end 55a close to the top plate heat dissipation portion 34, making it easy to reduce thermal resistance between the first coil end 55a and the top plate heat dissipation portion 34. This increases the amount of heat dissipated from the first coil end 55a to the outside of the motor 10 via the top plate 18 and the top plate heat dissipation portion 34. This more effectively prevents the temperature of the first coil end 55a from becoming too high.

[0054] When a current is sequentially supplied to each of the multiple coils 54 from a power source (not shown), the coils 54 sequentially form electromagnets with their magnetic poles facing radially. This creates a rotating magnetic field between the magnets 42 of the rotor 40 and each of the teeth 51 c of the stator 50, causing the rotor 40 and the shaft 44 to rotate about the central axis J. This causes the rotor blades 93 fixed to the shaft 44 to rotate about the central axis J.

[0055] Next, the airflow AF flowing through the heat dissipation section 30 will be described. As shown in FIG. 4 , in the following description, any four second heat dissipation sections 33 arranged in a row along the second direction D2 will be referred to as second heat dissipation sections 33a, 33b, 33c, and 33d, and five first heat dissipation sections 31 arranged in a row along the second direction D2 will be referred to as first heat dissipation sections 31e, 31f, 31g, 31h, and 31k. The second heat dissipation sections 33a, 33b, 33c, and 33d are arranged in this order from one side (+D2 side) of the second direction D2 to the other side (-D2 side) of the second direction D2. The first heat dissipation sections 31e, 31f, 31g, 31h, and 31k are arranged in this order from one side (+D2 side) of the second direction D2 to the other side (-D2 side) of the second direction D2. In the second direction D2, the first heat dissipation portion 31f is disposed between the second heat dissipation portions 33a and 33b, the first heat dissipation portion 31g is disposed between the second heat dissipation portions 33b and 33c, and the first heat dissipation portion 31h is disposed between the second heat dissipation portions 33c and 33d. The space between the second heat dissipation portions 33a and 33b is the second flow path 38a, the space between the second heat dissipation portions 33b and 33c is the second flow path 38b, and the space between the second heat dissipation portions 33c and 33d is the second flow path 38c. The space between the first heat dissipation section 31e and the first heat dissipation section 31f is the first flow path 37a, the space between the first heat dissipation section 31f and the first heat dissipation section 31g is the first flow path 37b, the space between the first heat dissipation section 31g and the first heat dissipation section 31h is the first flow path 37c, and the space between the first heat dissipation section 31h and the first heat dissipation section 31k is the first flow path 37d.

[0056] As described above, when the rotor 93 rotates around the central axis J together with the shaft 44, as shown in FIG. 2, airflow AF flows from the upper side of the housing 11, i.e., from one side (+D1 side) of the first direction D1, toward the top plate 18, the heat dissipation section 30, and the top plate heat dissipation section 34. In this embodiment, as shown in FIG. 4, the airflow AF flows downward, i.e., from the other side (-D1 side) of the first direction D1 toward the other side (-D2 side) of the second direction D2. After hitting the surface of each second heat dissipation section 33 facing one side (+D2 side) of the second direction D2, a portion of the airflow AF flows toward the other side of the first direction D1 through the space between the second heat dissipation sections 33 arranged adjacent to each other in the second direction D2. As described above, in the second direction D2, each of the multiple first heat dissipation sections 31 is positioned offset from each of the multiple second heat dissipation sections 33. Therefore, the air AF flowing between the second heat dissipation sections 33 toward the other side of the first direction D1 is branched by the first heat dissipation sections 31 to one side of the second direction D2 and the other side of the second direction D2, and then flows toward the other side of the first direction D1 between the first heat dissipation sections 31 arranged adjacent to each other in the second direction D2.

[0057] More specifically, the air AF flowing through second flow path 38a toward the other side of first direction D1 (-D1 side) is branched by first heat dissipation section 31f to one side of second direction D2 (+D2 side) and the other side of second direction D2 (-D2 side), respectively, and flows through first flow path 37a and first flow path 37b toward the other side of first direction D1. The air AF flowing through second flow path 38b toward the other side of first direction D1 is branched by first heat dissipation section 31g to one side of second direction D2 and the other side of second direction D2, respectively, and flows through first flow path 37b and first flow path 37c toward the other side of first direction D1. The air AF flowing through the second flow path 38c toward the other side of the first direction D1 is branched by the first heat dissipation portion 31h to one side of the second direction D2 and the other side of the second direction D2, and flows through each of the first flow paths 37c and 37d toward the other side of the first direction D1. As a result, the air AF flows toward the other side of the first direction D1 while coming into contact with each of the first heat dissipation portions 31 and each of the second heat dissipation portions 33, thereby suppressing variation in the amount of heat dissipated from each heat dissipation portion 30 to the outside of the motor 10 in the second direction D2.

[0058] The member 95 shown in FIG. 5 is, for example, a member that attaches the motor 10 to the frame 92 shown in FIG. 1 . The member 95 is disposed on one side (+D1 side) of the second heat dissipation portion 33 in the first direction D1. The member 95 is disposed on one side (+D1 side) of each of the second heat dissipation portion 33b and the second heat dissipation portion 33c in the first direction D1. Therefore, the member 95 prevents the wind AF from flowing into the second flow path 38b. In contrast, in this embodiment, as described above, the wind AF that flows through the second flow path 38a toward the other side (-D1 side) of the first direction D1 and is branched by the first heat dissipation portion 31f to the other side (-D2 side) of the second direction D2 flows through the first flow path 37b toward the other side (-D2 side) of the first direction D1. Furthermore, among the airflow AF flowing through the second flow path 38c toward the other side of the first direction D1, the airflow AF branched to one side of the second direction D2 (+D2 side) by the first heat dissipation portion 31h flows through the first flow path 37c toward the other side of the first direction D1. This allows the airflow AF to be supplied to the first heat dissipation portion 31g, which is positioned so as to overlap with the second flow path 38b as viewed from the first direction D1. This allows the airflow AF to flow toward the other side of the first direction D1 while coming into contact with each first heat dissipation portion 31, thereby suppressing variation in the amount of heat dissipated from each heat dissipation portion 31 to the outside of the motor 10.

[0059] In this embodiment, as described above, the airflow AF tends to flow evenly through the flow paths between the first heat dissipation sections 31, so the cooling performance of the first heat dissipation section 31 is higher than that of the second heat dissipation section 33. Furthermore, in this embodiment, the dimension of the first heat dissipation section 31 in the first direction D1 is larger than the dimension of the second heat dissipation section 33 in the first direction D1. As a result, in this embodiment, a wide area with high cooling performance can be secured on the outer peripheral surface of the housing 11. Therefore, the amount of heat dissipated from the stator 50 to the outside of the motor 10 can be suitably increased.

[0060] According to this embodiment, the motor 10 includes a rotor 40 rotatable about a central axis J, a stator 50 facing the rotor 40 at a distance, and a housing 11 that accommodates the rotor 40 and the stator 50. The housing 11 includes a housing main body 12 that surrounds the stator 50, and a plurality of heat dissipation portions 30 that protrude from the outer surface of the housing main body 12 to the outside of the housing main body 12 and extend in a first direction D1. The plurality of heat dissipation portions 30 include a plurality of first heat dissipation portions 31 and a plurality of second heat dissipation portions 33, and ends of the plurality of second heat dissipation portions 33 on one side in the first direction D1 (+D1 side) are located closer to one side in the first direction D1 than the plurality of first heat dissipation portions 31, and each of the plurality of first heat dissipation portions 31 is positioned at a position offset from each of the plurality of second heat dissipation portions 33 in the second direction D2. Therefore, in this embodiment, as described above, the airflow AF flowing between the second heat dissipation sections 33 toward the other side (−D1 side) of the first direction D1 is branched by the first heat dissipation sections 31 toward one side (+D2 side) of the second direction D2 and the other side (−D2 side) of the second direction D2, and then flows toward the other side of the first direction D1 between the first heat dissipation sections 31 arranged adjacent to each other in the second direction D2. Therefore, even if, for example, the member 95 for attaching the motor 10 to the frame 92 is arranged on one side of the second heat dissipation section 33 in the first direction D1, the airflow AF can flow toward the other side of the first direction D1 while contacting each of the first heat dissipation sections 31, as described above. This suppresses variation in the amount of heat dissipated from each heat dissipation section 30 to the outside of the motor 10 in the second direction D2. This makes it possible to suppress variations in the amount of heat dissipated from the stator 50 to the outside of the motor 10 via the heat dissipation portions 30 in the second direction D2. This prevents the temperature of a portion of the stator 50 from becoming too high, thereby suppressing deterioration of the stator 50.

[0061] According to this embodiment, the ends of the multiple second heat dissipation sections 33 on one side in the first direction D1 (+D1 side) are located closer to the housing main body 12 in the first direction D1. As described above, the airflow AF flowing toward the housing 11 due to the rotation of the rotor 93 flows in a direction inclined from the other side in the first direction D1 (-D1 side) toward the second direction D2. Therefore, compared to a configuration in which the ends of the multiple second heat dissipation sections 33 on one side in the first direction D1 are located closer to the housing main body 12 in the first direction D1, each second heat dissipation section 33 can more easily guide the airflow AF toward the other side in the first direction D1. This increases the volume of airflow AF flowing between the second heat dissipation sections 33 and between the first heat dissipation sections 31. This increases the amount of heat dissipated from the stator 50 to the outside of the motor 10 via the heat dissipation section 30. This more effectively prevents the temperature of the stator 50 from becoming too high.

[0062] According to this embodiment, the first heat dissipation portions 31 and the second heat dissipation portions 33 are alternately arranged in the second direction D2. This makes it easier to suppress variations in the amount of airflow AF supplied to each first heat dissipation portion 31, thereby suppressing variations in the amount of heat dissipated from each first heat dissipation portion 31 to the outside of the motor 10. Therefore, since variations in the amount of heat dissipated from the stator 50 to the outside of the motor 10 via the heat dissipation portions 30 in the second direction D2 can be more effectively suppressed, it is possible to more effectively prevent the temperature of a portion of the stator 50 from becoming too high.

[0063] According to this embodiment, each of the multiple first heat dissipation portions 31 has a first surface 32a facing one side (+D2 side) in the second direction D2 and a second surface 32c facing the other side (-D2 side) in the second direction D2, and the portion of the first surface 32a on one side (+D1 side) in the first direction D1 is positioned on the other side in the second direction D2 as it approaches the one side in the first direction D1, and the portion of the second surface 32c on one side in the first direction D1 is positioned on one side in the second direction as it approaches the one side in the first direction D1. Therefore, as described above, the portion on one side in the first direction D1 of each first heat dissipation portion 31 can be formed into a pointed shape facing the one side in the first direction D1 when viewed in the radial direction. Therefore, compared to a configuration in which one portion of the first heat dissipation section 31 on one side in the first direction D1 is rectangular when viewed from the radial direction, the first surface 32a can guide the airflow AF toward one side in the second direction D2, and the second surface 32c can guide the airflow AF toward the other side in the second direction D2. This makes it possible to prevent the first heat dissipation section 31 from impeding the smooth flow of the airflow AF, thereby more preferably increasing the amount of airflow AF supplied to each first heat dissipation section 31. This therefore makes it possible to more preferably increase the amount of heat dissipated from the stator 50 to the outside of the motor 10 via the heat dissipation section 30, more preferably preventing the temperature of the stator 50 from becoming too high.

[0064] According to this embodiment, the stator 50 is disposed radially outward of the rotor 40. The stator 50 includes a stator core 51 facing the rotor 40 and a coil portion 54 attached to the stator core 51. The coil portion 54 has a coil end portion 55 protruding axially from the stator core 51. When viewed radially, the coil end portion 55 overlaps with the first heat dissipation portion 31 and the second heat dissipation portion 33. This allows the coil end portion 55 to be disposed close to the first heat dissipation portion 31 and the second heat dissipation portion 33. This effectively increases the amount of heat dissipated from the coil end portion 55 to the outside of the motor 10 via the heat dissipation portion 30. This effectively prevents the temperature of the coil end portion 55 from becoming too high, thereby effectively preventing the coil portion 54 from deteriorating.

[0065] According to this embodiment, the flying object 90 includes a motor 10 and a rotor 93 connected to the motor 10. As described above, in this embodiment, even if the member 95 that attaches the motor 10 to the frame 92 is positioned on one side (+D1 side) of the second heat dissipation section 33 in the first direction D1, the airflow AF can be supplied to each first heat dissipation section 31. This prevents variations in the amount of heat dissipated from the stator 50 to the outside of the motor 10 via each heat dissipation section 30 in the second direction D2. This prevents the temperature of a portion of the stator 50 from becoming too high, thereby preventing deterioration of the stator 50. This improves the durability of the flying object 90.

[0066] 6, a motor 210 of this embodiment is a disk-shaped motor centered on a central axis J. In the following description, the same components as those of the first embodiment are denoted by the same reference numerals, and description thereof will be omitted. The motor 210 of this embodiment includes a housing 211, a rotor 40, a shaft 44, and a stator 50.

[0067] The housing 211 has a generally cylindrical shape and extends in the axial direction about a central axis J. The housing 211 includes a first housing 13, a second housing 16, a housing main body 12, a heat dissipation section 230, and a top plate heat dissipation section .

[0068] The heat dissipation portion 230 protrudes from the outer surface of the housing main body 12 to the outside of the housing main body 12. More specifically, the heat dissipation portion 230 protrudes radially outward from the surface of the cylindrical portion 12a facing radially outward. As shown in FIG. 7 , in this embodiment, the heat dissipation portion 230 extends in the first direction D1. In this embodiment, the housing 211 has multiple heat dissipation portions 230. The heat dissipation portions 230 are arranged at intervals from one another along the second direction D2. The multiple heat dissipation portions 230 include multiple first heat dissipation portions 231 and multiple second heat dissipation portions 233.

[0069] As shown in Fig. 6, the first heat dissipation portion 231 is a plate-like member that protrudes radially outward from the surface of the cylindrical portion 12a that faces radially outward. As shown in Fig. 7, each first heat dissipation portion 231 extends in the axial direction. In the axial direction, the lower end of each first heat dissipation portion 231 is located at the same position as the lower end of the cylindrical portion 12a. In the axial direction, the upper end of each first heat dissipation portion 231 is located lower than the upper end of the cylindrical portion 12a. The first heat dissipation portions 231 are arranged at intervals from each other along the second direction D2. The first heat dissipation portion 231 is composed of a first portion 31a and a second portion 231c.

[0070] The second portion 231c is an upper portion of the first heat dissipation portion 231. Each second portion 231c protrudes radially outward from the surface of the cylindrical portion 12a that faces radially outward of the second circumferential wall portion 17. Each second portion 231c extends in the axial direction. In the axial direction, the upper end of each second portion 231c is located lower than the upper end of the second circumferential wall portion 17. In the axial direction, the lower end of each second portion 231c is located at the same position as the lower end of the second circumferential wall portion 17. The lower end of each second portion 231c contacts the upper end of a different first portion 31a.

[0071] As shown in FIG. 6 , the second heat dissipation portion 233 is a plate-like member that protrudes radially outward from the radially outward surface of the cylindrical portion 12a. As shown in FIG. 7 , each second heat dissipation portion 233 extends in the axial direction. An end portion of each second heat dissipation portion 233 on one side in the first direction D1 (+D1 side) is located closer to one side in the first direction D1 than each first heat dissipation portion 231. An end portion of each second heat dissipation portion 233 on one side in the first direction D1 is located higher than the housing main body 12. In this embodiment, an end portion of each first heat dissipation portion 231 on one side in the first direction D1 is located closer to one side in the first direction D1 than an end portion of each second heat dissipation portion 233 on the other side in the first direction D1 (-D1 side). As a result, when viewed from the second direction D2, a portion of each first heat dissipation portion 231 on one side in the first direction D1 overlaps a portion of each second heat dissipation portion 233 on the other side in the first direction D1. The second heat dissipation portions 233 are arranged at intervals from one another along the second direction D2. In the second direction D2, each of the multiple first heat dissipation portions 231 is arranged at a position offset from each of the multiple second heat dissipation portions 233. In this embodiment, the first heat dissipation portions 231 and the second heat dissipation portions 233 are arranged alternately in the second direction D2. Other configurations of the heat dissipation portion 230 of this embodiment are similar to those of the heat dissipation portion 30 of the first embodiment described above. Other configurations of the motor 210 of this embodiment are similar to those of the motor 10 of the first embodiment described above.

[0072] Next, the airflow AF flowing through the heat dissipation section 230 will be described. As shown in FIG. 7 , in the following description, any four second heat dissipation sections 233 arranged in a row along the second direction D2 will be referred to as second heat dissipation sections 233a, 233b, 233c, and 233d, and five first heat dissipation sections 231 arranged in a row along the second direction D2 will be referred to as first heat dissipation sections 231e, 231f, 231g, 231h, and 231k. The second heat dissipation sections 233a, 233b, 233c, and 233d are arranged in this order from one side (+D2 side) of the second direction D2 to the other side (-D2 side) of the second direction D2. The first heat dissipation sections 231e, 231f, 231g, 231h, and 231k are arranged in this order from one side (+D2 side) of the second direction D2 to the other side (-D2 side) of the second direction D2. In the second direction D2, first heat dissipation portion 231f is disposed between second heat dissipation portion 233a and second heat dissipation portion 233b, first heat dissipation portion 231g is disposed between second heat dissipation portion 233b and second heat dissipation portion 233c, and first heat dissipation portion 231h is disposed between second heat dissipation portion 233c and second heat dissipation portion 233d. In addition, the space between second heat dissipation portion 233a and second heat dissipation portion 233b is second flow path 238a, the space between second heat dissipation portion 233b and second heat dissipation portion 233c is second flow path 238b, and the space between second heat dissipation portion 233c and second heat dissipation portion 233d is second flow path 238c. The space between the first heat dissipation section 231e and the first heat dissipation section 231f is the first flow path 237a, the space between the first heat dissipation section 231f and the first heat dissipation section 231g is the first flow path 237b, the space between the first heat dissipation section 231g and the first heat dissipation section 231h is the first flow path 237c, and the space between the first heat dissipation section 231h and the first heat dissipation section 231k is the first flow path 237d.

[0073] As in the first embodiment described above, the airflow AF that flows when the rotor 93 rotates together with the shaft 44 about the central axis J flows in a direction inclined from the other side of the first direction D1 (-D1 side) to the other side of the second direction D2 (-D2 side). The airflow AF that flows through the second flow path 238a toward the other side of the first direction D1 is branched by the first heat dissipation portion 231f into one side of the second direction D2 (+D2 side) and the other side of the second direction D2 (-D2 side), respectively, and flows through each of the first flow paths 237a and 237b toward the other side of the first direction D1. The air AF flowing through second flow path 238b toward the other side of first direction D1 is branched by first heat dissipation section 231g into one side of second direction D2 and the other side of second direction D2, and flows through first flow path 237b and first flow path 237c toward the other side of first direction D1. The air AF flowing through second flow path 238c toward the other side of first direction D1 is branched by first heat dissipation section 231h into one side of second direction D2 and the other side of second direction D2, and flows through first flow path 237c and first flow path 237d toward the other side of first direction D1.

[0074] As shown in FIG. 8 , the member 95 is disposed on one side (+D1 side) of the second heat dissipation portion 233 in the first direction D1. The member 95 is disposed on one side (+D1 side) of each of the second heat dissipation portion 233b and the second heat dissipation portion 233c in the first direction D1. Therefore, the member 95 prevents the airflow AF from flowing into the second flow path 238b. In contrast, in the present embodiment, as in the first embodiment described above, the airflow AF flowing through the second flow path 238a toward the other side (+D1 side) of the first direction D1 is diverted by the first heat dissipation portion 231f to the other side (-D2 side) of the second direction D2, and flows through the first flow path 237b toward the other side of the first direction D1. Furthermore, among the airflow AF flowing through the second flow path 238c toward the other side of the first direction D1, the airflow AF branched to one side of the second direction D2 (the +D2 side) by the first heat dissipation portion 231h flows through the first flow path 237c toward the other side of the first direction D1. This allows the airflow AF to be supplied to the first heat dissipation portion 231g, which is positioned so as to overlap with the second flow path 238b as viewed from the first direction D1. This allows the airflow AF to flow toward the other side of the first direction D1 while coming into contact with each of the first heat dissipation portions 231, thereby suppressing variation in the amount of heat dissipated from each heat dissipation portion 230 to the outside of the motor 10.

[0075] According to this embodiment, the multiple heat dissipation units 230 include multiple first heat dissipation units 231 and multiple second heat dissipation units 233. The ends of the multiple second heat dissipation units 233 on one side (+D1 side) of the first direction D1 are located closer to the first direction D1 than the multiple first heat dissipation units 231. In the second direction D2, each of the multiple first heat dissipation units 231 is positioned offset from each of the multiple second heat dissipation units 233. Thus, as in the first embodiment described above, even if, for example, a member 95 that attaches the motor 210 to a frame 92 provided on the flying object 290 is positioned on one side of the second heat dissipation units 233 in the first direction D1, the airflow AF can flow toward the other side (-D1 side) of the first direction D1 while contacting each of the first heat dissipation units 231. This suppresses variation in the amount of heat dissipated from each heat dissipation unit 230 to the outside of the motor 210 in the second direction D2. This makes it possible to suppress variations in the amount of heat dissipated from the stator 50 to the outside of the motor 210 in the second direction D2 via the heat dissipation portions 230. This prevents the temperature of a portion of the stator 50 from becoming too high, thereby suppressing deterioration of the stator 50.

[0076] According to this embodiment, the ends of the first heat dissipation sections 231 on one side in the first direction D1 (+D1 side) are positioned closer to one side in the first direction D1 than the ends of the second heat dissipation sections 233 on the other side in the first direction D1 (-D1 side). Therefore, as described above, when viewed from the second direction D2, the portions of the first heat dissipation sections 231 on one side in the first direction D1 can be arranged to overlap the portions of the second heat dissipation sections 233 on the other side in the first direction D1. This makes it possible to suppress leakage of air AF from between the first heat dissipation sections 231 and the second heat dissipation sections 233, compared to a configuration in which the first heat dissipation sections 231 and the second heat dissipation sections 233 are spaced apart from one another in the first direction D1. This makes it possible to suitably increase the volume of air AF supplied to each first heat dissipation section 231. This makes it possible to preferably increase the amount of heat radiated from the stator 50 to the outside of the motor 210 via each heat radiating portion 230. This makes it possible to preferably prevent the temperature of the stator 50 from becoming too high.

[0077] 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 number of motors and the number of rotors provided in the aircraft may be three or less, or five or more.

[0078] An end portion of each second heat dissipation portion on one side in the first direction may be located below the housing main body. Also, the dimension of each second heat dissipation portion in the second direction may be greater than or the same as the dimension of each first heat dissipation portion in the second direction.

[0079] 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.

[0080] The present technology may be configured as follows: (1) A motor including a rotor rotatable about a central axis, a stator facing the rotor at a distance, and a housing accommodating the rotor and the stator, wherein the housing has a housing main body surrounding the stator and a plurality of heat dissipation portions protruding from an outer surface of the housing main body to the outside of the housing main body and extending in a first direction, the plurality of heat dissipation portions including a plurality of first heat dissipation portions and a plurality of second heat dissipation portions, wherein end portions of one side in the first direction of the plurality of second heat dissipation portions are located on one side in the first direction of the plurality of first heat dissipation portions, and each of the plurality of first heat dissipation portions is positioned at a position offset from each of the plurality of second heat dissipation portions in a second direction intersecting both the direction in which the plurality of heat dissipation portions protrude and the first direction. (2) The motor described in (1), wherein end portions of one side in the first direction of the plurality of first heat dissipation portions are located on the other side in the first direction of end portions of the plurality of second heat dissipation portions on the other side in the first direction. (3) The motor described in (1), wherein ends of the plurality of first heat dissipation sections on one side in the first direction are positioned closer to one side in the first direction than ends of the plurality of second heat dissipation sections on the other side in the first direction. (4) The motor described in any one of (1) to (3), wherein ends of the plurality of second heat dissipation sections on one side in the first direction are positioned closer to one side in the first direction than the housing main body. (5) The motor described in any one of (1) to (4), wherein the first heat dissipation sections and the second heat dissipation sections are arranged alternately in the second direction. (6) The motor described in any one of (1) to (5), wherein each of the plurality of first heat dissipation sections has a first surface facing one side in the second direction and a second surface facing the other side in the second direction, and wherein a portion of the first surface on one side in the first direction is positioned closer to the other side in the second direction as it approaches the one side in the first direction, and a portion of the second surface on one side in the first direction is positioned closer to one side in the second direction as it approaches the one side in the first direction. (7) The motor according to any one of (1) to (6), wherein the dimension of each of the second heat dissipation portions in the second direction is smaller than the dimension of each of the first heat dissipation portions in the second direction.(8) The motor according to any one of (1) to (7), wherein the stator is disposed radially outward of the rotor, the stator has a stator core facing the rotor and a coil portion attached to the stator core, the coil portion has coil end portions protruding in the axial direction from the stator core, and the coil end portions overlap with the first heat dissipation portion and the second heat dissipation portion, as viewed from the radial direction. (9) An aircraft comprising the motor according to any one of (1) to (8) and a rotor connected to the motor.

[0081] 10,210...Motor, 11,211...Housing, 12...Housing main body, 30,230...Heat dissipation section, 31,231...First heat dissipation section, 32a...First surface, 32c...Second surface, 33,233...Second heat dissipation section, 40...Rotor, 50...Stator, 51...Stator core, 54...Coil section, 55...Coil end section, 90,290...Aircraft, 93...Rotor blade, D1...First direction, D2...Second direction, J...Central axis, W1...Dimension of first heat dissipation section in second direction, W2...Dimension of second heat dissipation section in second direction

Claims

1. A motor comprising: a rotor rotatable about a central axis; a stator facing the rotor with a gap between them; and a housing accommodating the rotor and the stator, wherein the housing has a housing main body surrounding the stator and a plurality of heat dissipation portions protruding from the outer surface of the housing main body to the outside of the housing main body and extending in a first direction, the plurality of heat dissipation portions include a plurality of first heat dissipation portions and a plurality of second heat dissipation portions, ends of one side in the first direction of the plurality of second heat dissipation portions are located on one side in the first direction of the plurality of first heat dissipation portions, and each of the plurality of first heat dissipation portions is positioned offset from each of the plurality of second heat dissipation portions in a second direction intersecting both the direction in which the plurality of heat dissipation portions protrude and the first direction.

2. The motor described in claim 1, wherein the ends of the first heat dissipation sections on one side in the first direction are located on the other side in the first direction than the ends of the second heat dissipation sections on the other side in the first direction.

3. A motor as described in claim 1, wherein the ends of the plurality of first heat dissipation sections on one side in the first direction are located on the one side in the first direction of the ends of the plurality of second heat dissipation sections on the other side in the first direction.

4. A motor according to any one of claims 1 to 3, wherein the ends of the second heat dissipation portions on one side in the first direction are located on the one side in the first direction of the housing main body portion.

5. The motor according to any one of claims 1 to 3, wherein the first heat dissipation portions and the second heat dissipation portions are arranged alternately in the second direction.

6. A motor as described in any one of claims 1 to 3, wherein each of the plurality of first heat dissipation sections has a first surface facing one side in the second direction and a second surface facing the other side in the second direction, a portion of the first surface on one side in the first direction being positioned on the other side in the second direction as it approaches the one side in the first direction, and a portion of the second surface on one side in the first direction being positioned on one side in the second direction as it approaches the one side in the first direction.

7. A motor according to any one of claims 1 to 3, wherein the dimension of each of the second heat dissipation sections in the second direction is smaller than the dimension of each of the first heat dissipation sections in the second direction.

8. A motor as described in any one of claims 1 to 3, wherein the stator is positioned radially outward of the rotor, the stator has a stator core facing the rotor and a coil portion attached to the stator core, the coil portion has coil end portions protruding axially from the stator core, and when viewed radially, the coil end portions overlap with each of the first heat dissipation portion and the second heat dissipation portion.

9. An aircraft comprising: a motor according to any one of claims 1 to 3; and a rotor connected to the motor.

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