Driving device

Abstract

To provide a driving device capable of enhancing a heat dissipation effect of a housing.SOLUTION: An inverter device 80 includes: an inverter housing 90; and an inverter part 170. The inverter part 170 is housed in the inverter housing 90. In the inverter housing 90, a first fin 921 and a second fin 922 are provided. The first fin 921 and the second fin 922 are arranged to a shaft direction AD along an inverter outer peripheral surface 910. The first fin 921 and the second fin 922 are extended to the shaft direction AD from a position arranged to a radial direction RD to the inverter part 170. The first fin 921 is extended to an upstream side from the inverter part 170. The second fin 922 is extended to a downstream side from the inverter part 170.SELECTED DRAWING: Figure 7

Description

[Technical field]

[0001] The disclosure herein relates to a drive arrangement. [Background technology]

[0002] Patent Document 1 describes a drive device provided with heat dissipation fins. In this drive device, a plurality of heat dissipation fins are provided on the outer surface of the housing. The heat dissipation fins extend in a serpentine shape along the outer surface of the housing. Patent Document 1 describes that the serpentine shape of the heat dissipation fins promotes the generation of turbulence in the air flowing between two adjacent heat dissipation fins, thereby improving the heat dissipation capacity of the heat dissipation fins. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2008-186820 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the above-mentioned Patent Document 1, the entire heat dissipation fin is meandering, which may increase the pressure loss between two adjacent heat dissipation fins. If the pressure loss increases, the amount of air flowing between the two adjacent heat dissipation fins will decrease, and there is a concern that the heat dissipation effect of the heat dissipation fins will decrease.

[0005] One object of the present disclosure is to provide a drive device that can improve the heat dissipation effect of the housing. [Means for solving the problem]

[0006] The various aspects disclosed in this specification employ different technical means to achieve their respective objectives. The reference symbols in parentheses in the claims and in this section are merely examples showing the correspondence with the specific means described in the embodiments below as one aspect, and do not limit the technical scope.

[0007] In order to achieve the above object, the disclosed embodiment comprises: A drive device (50) driven by electricity, A heat generating portion (170) that generates heat when current is applied; A housing (90) having an outer peripheral surface (910) extending in an axial direction (AD) and accommodating a heat generating portion; a plurality of outer peripheral fins (92) extending in the axial direction along the outer peripheral surface of the housing, arranged in the circumferential direction (CD) of the housing along the outer peripheral surface of the housing, and dissipating heat from a heat generating portion to the outside of the housing; Equipped with The housing outer circumferential surface has a first surface end portion (910a) and a second surface end portion (910b) that are a pair of end portions aligned in the axial direction, The plurality of peripheral fins include a first outer peripheral fin (921, 921A) extending from a position aligned with the heat generating portion in a radial direction (RD) of the housing toward the first surface end of the first surface end and the second surface end; a second outer circumferential fin (922, 922A) provided at a position away from the first outer circumferential fin in a direction perpendicular to the radial direction and extending from a position aligned radially with the heat generating portion toward the second surface end of the first surface end and the second surface end; It is a drive device having the above structure.

[0008] According to the above aspect, the first outer fin and the second outer fin are provided at positions spaced apart in a direction perpendicular to the axial direction. In this configuration, turbulence such as eddy currents is likely to occur in the gas such as air flowing through the space between the first outer fin and the second outer fin at the position radially aligned with the heat generating portion. Therefore, the turbulence of the gas can enhance the heat dissipation effect of the heat of the heat generating portion being released through the first outer fin, the second outer fin, and the outer circumferential surface of the housing. In this way, the turbulence of the gas occurs locally at the position radially aligned with the heat generating portion on the outside of the housing, thereby suppressing an increase in pressure loss in the entire space between two circumferentially adjacent outer fins. Therefore, the heat dissipation effect of the heat generating portion by the gas can be enhanced while suppressing a shortage of the amount of gas flowing between two circumferentially adjacent outer fins. As described above, the heat dissipation effect of the housing in the drive device can be enhanced by the outer circumferential fin. [Brief description of the drawings]

[0009] [Figure 1] FIG. 1 is a diagram showing the configuration of an eVTOL in a first embodiment. [Diagram 2] FIG. 2 is a diagram showing the electrical configuration of the propulsion system. [Diagram 3] FIG. [Figure 4] FIG. [Diagram 5] Cross-sectional view of line VV in Figure 3. [Figure 6] 6 is a cross-sectional view of the inverter device taken along line VI-VI in FIG. 4 ; [Figure 7] FIG. 4 is an enlarged side view of a switch part in the inverter device. [Figure 8] FIG. 1 is a diagram for explaining a thermal boundary layer. [Figure 9] FIG. 4 is an enlarged side view of the vicinity of a motor radial line in the inverter device. [Figure 10] An enlarged side view of a switch part in an inverter device in Comparative Example 2. [Figure 11] FIG. 11 is an enlarged side view of the periphery of a switch component in the inverter device in Comparative Example 2. [Figure 12]FIG. 11 is an enlarged side view of the periphery of a motor radial line in the inverter device according to the second embodiment. [Figure 13] FIG. 11 is an enlarged side view of the periphery of a motor radial line in the inverter device according to the third embodiment. [Figure 14] FIG. 13 is a plan view of an inverter device according to a fourth embodiment. [Figure 15] Cross-sectional view of line XV-XV in Figure 16. [Figure 16] Cross-sectional view of line XVI-XVI in Figure 14. [Figure 17] Cross-sectional view of line XVII-XVII in Figure 16. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, a number of embodiments for carrying out the present disclosure will be described with reference to the drawings. In each embodiment, the same reference numerals may be used to designate parts corresponding to matters described in the preceding embodiment, and duplicated descriptions may be omitted. In each embodiment, when only a part of the configuration is described, other embodiments described previously may be applied to other parts of the configuration. In addition to combinations of parts that are specifically indicated as being possible in each embodiment, it is also possible to partially combine embodiments even if not indicated, as long as there is no particular problem with the combination.

[0011] First Embodiment The eVTOL10 shown in FIG. 1 is an electric vertical take-off and landing aircraft. An electric vertical take-off and landing aircraft is an electric vertical take-off and landing aircraft, and is capable of vertical take-off and landing. eVTOL is an abbreviation for electric Vertical Take-Off and Landing aircraft. The eVTOL10 is an electric flying object that flies in the atmosphere, and is sometimes called an electric flying object. The eVTOL10 is also an electric aircraft, and is sometimes called an electric aircraft. The eVTOL10 is a manned flying object with a crew member on board. The crew member of the eVTOL10 includes a pilot as a pilot or driver.

[0012] The eVTOL 10 has an airframe 11 and a propeller 20. The airframe 11 has an airframe main body 12 and wings 13. The airframe main body 12 is the fuselage of the airframe 11 and has a shape that extends, for example, in the front-to-rear direction. The airframe main body 12 has a passenger compartment 14 for passengers to ride in. The wings 13 extend from the airframe main body 12 and multiple wings 13 are provided on the airframe main body 12. The wings 13 are fixed wings. The multiple wings 13 include main wings, a tail, and the like.

[0013] The eVTOL 10 has a cabin. The cabin is provided inside the eVTOL 10. For example, the cabin is an internal space of the aircraft body 12, and is formed by the aircraft body 12. The cabin can be a crew cabin 14 or a cargo room. The crew cabin 14 can be a passenger cabin or a pilot cabin. The crew cabin 14 is provided with seats for the crew to sit in. The crew cabin 14 does not need to have a crew member on board, and may store cargo.

[0014] A plurality of propellers 20 are provided on the airframe 11. The eVTOL 10 is a multicopter having at least three propellers 20. For example, at least six propellers 20 are provided on the airframe 11. The propellers 20 are provided on each of the airframe body 12 and the wings 13. The propellers 20 rotate about a propeller axis. The propeller axis is, for example, the center line of the propeller 20. The propellers 20 can generate thrust and lift for the eVTOL 10. The propellers 20 are sometimes referred to as rotors or rotating wings.

[0015] In the eVTOL 10, the multiple propellers 20 make it easier to maintain aircraft balance. Even if the propeller output of one propeller 20 is unintentionally reduced, the eVTOL 10 can continue flying using the remaining propellers 20. The propeller output includes the rotation speed and torque of the propellers 20.

[0016] The propeller 20 has blades, a boss, and a propeller shaft. A plurality of blades are arranged in the circumferential direction of the propeller axis. The boss connects the plurality of blades. The propeller shaft is the rotation axis of the propeller 20, and extends from the boss along the propeller axis.

[0017] Flight modes of the eVTOL10 include vertical takeoff, vertical landing, cruise, hovering, etc. Flight modes are sometimes referred to as flight modes. In vertical takeoff, the eVTOL10 can take off without running. In vertical takeoff, the eVTOL10 may rise vertically or rise diagonally upward. In vertical landing, the eVTOL10 can land without running. In vertical landing, the eVTOL10 may descend vertically or descend diagonally downward.

[0018] Cruise may be referred to as horizontal flight. In cruise, the eVTOL 10 may fly horizontally without moving vertically, or may fly horizontally while moving vertically. Hovering may be referred to as stationary flight. In hovering, the eVTOL 10 may fly as if it is stopped at a predetermined position in the air, or the eVTOL 10 may deviate vertically or horizontally from the predetermined position.

[0019] The flight mode of the eVTOL10 also includes a lift. In the lift, the eVTOL10 moves in the up and down directions. The eVTOL10 may rise diagonally upward or descend diagonally downward as a lift. The eVTOL10 takes off vertically by lifting upward. The eVTOL10 lands vertically by lifting downward.

[0020] The eVTOL10 is a tilt rotor aircraft. In the eVTOL10, the tilt angle of the propeller 20 is adjustable. In the eVTOL10, one propeller 20 can function as both a lift propeller and a cruise propeller. For example, when the eVTOL10 lifts, the tilt angle is adjusted so that the propeller 20 functions as a lift rotor. When the eVTOL10 cruises, the tilt angle is adjusted so that the propeller 20 functions as a cruise rotor. Note that the eVTOL10 does not have to be a tilt rotor aircraft. For example, the eVTOL10 may have a lift propeller 20 and a cruise propeller 20 separately.

[0021] The propulsion system 30 shown in Fig. 2 is mounted on the eVTOL 10. The propulsion system 30 is a system that drives the eVTOL 10 to propel it. The propulsion system 30 has a battery 31 and an EPU 50. The battery 31 and the EPU 50 are mounted on the EPU 50. The propulsion system 30 has a flight control device (not shown). The flight control device performs flight control for flying the eVTOL 10. In the flight control, the propulsion system 30 and the EPU 50 are controlled.

[0022] The battery 31 is connected to the EPU 50 so that it can be electrically connected thereto. The battery 31 is a power supply unit that supplies power to the EPU 50, and corresponds to a power supply unit. The battery 31 is a DC voltage source that applies a DC voltage to the EPU 50. The battery 31 has a secondary battery that can be charged and discharged. Examples of this secondary battery include a lithium ion battery and a nickel-metal hydride battery. The battery 31 is capable of storing power, and corresponds to a power storage device. Note that a fuel cell, a generator, or the like may be used as the power supply unit in addition to or instead of the battery 31.

[0023] In Figs. 1 and 2, the EPU 50 is a device driven by electricity and corresponds to a drive device. The EPU 50 drives the propeller 20 to rotate. EPU is an abbreviation for Electric Propulsion Unit. The EPU 50 is sometimes referred to as an electric drive device and an electric drive system. An EPU 50 is provided individually for each of the multiple propellers 20. The EPUs 50 are arranged on the propellers 20 along the propeller axis. All of the multiple EPUs 50 are fixed to the airframe 11. The EPUs 50 support the propellers 20 so that they can rotate. The EPUs 50 are connected to the propellers 20. The propellers 20 are fixed to the airframe 11 via the EPUs 50.

[0024] As shown in FIG. 1, the eVTOL 10 has a propulsion device 100. The propulsion device 100 is formed to include a propeller 20 and an EPU 50. The propulsion device 100 is a device for propelling the eVTOL 10. The propulsion device 100 rotates the propeller 20 to fly the eVTOL 10. The eVTOL 10 is also a moving body that moves by the propulsion device 100. A plurality of propulsion devices 100 are provided in the eVTOL 10. One propulsion device 100 includes one each of the propeller 20 and an EPU 50 for driving the propeller 20. Of the propeller 20 and the EPU 50, only the EPU 50 may be referred to as the propulsion device 100.

[0025] The EPU 50 has a motor device 60 and an inverter device 80. The motor device 60 has a motor 61 and a motor housing 70. The motor housing 70 is a housing and houses the motor 61. The motor 61 is a multi-phase AC motor. The motor 61 is a multi-phase AC rotating electric machine. The motor 61 is a flight drive source for the eVTOL 10 and functions as an electric motor. The motor 61 is a motor generator. The motor 61 functions as a generator during regeneration. As the motor 61, for example, a brushless motor is used.

[0026] The motor 61 enables the eVTOL 10 to fly by driving and rotating the propeller 20. The motor 61 is a flight motor for flying the eVTOL 10. The motor 61 drives and rotates the propeller 20 by being powered by battery power. The battery power is power supplied to the motor 61 from the battery 31.

[0027] As shown in FIG. 3, the motor 61 has a motor stator 62, a motor rotor 63, and a motor shaft 64. The motor stator 62 is a stator, and is fixed to a motor housing 70. The motor rotor 63 rotates relative to the motor stator 62. The rotation of the motor rotor 63 is sometimes referred to as the rotation of the motor 61. The motor shaft 64 rotates together with the motor rotor 63. The motor shaft 64 is rotatably supported by the motor housing 70 or the like. The motor shaft 64 is connected to the propeller 20. In the propulsion device 100, the propeller 20 rotates together with the motor shaft 64.

[0028] The motor 61 is, for example, an axial gap motor. In the motor 61, a motor stator 62 and a motor rotor 63 are arranged in the axial direction AD along the motor axis Cm. The motor 61 is a double rotor motor. In the motor 61, the two motor rotors 63 are arranged in the axial direction AD via the motor stator 62.

[0029] The motor axis Cm is the center line of the motor 61 and is a virtual line extending in a straight line. The motor rotor 63 rotates around the motor axis Cm. The motor axis Cm corresponds to the rotation axis. The axial direction AD is the direction in which the motor axis Cm extends. With respect to the motor axis Cm, the axial direction AD, the circumferential direction CD, and the radial direction RD are perpendicular to each other. The circumferential direction CD is the rotation direction of the motor 61. With respect to the radial direction RD, the outer side is sometimes referred to as the radial outer side or the outer circumferential side, and the inner side is sometimes referred to as the radial inner side or the inner circumferential side.

[0030] The inverter device 80 drives the motor device 60 by supplying power to the motor device 60. The inverter device 80 is a drive unit for driving the motor 61, and corresponds to a motor drive unit. The inverter device 80 has an inverter unit 170 and an inverter housing 90. The inverter housing 90 is a housing and houses the inverter unit 170. The inverter unit 170 is capable of converting power. The inverter unit 170 converts the power supplied from the battery 31 to the motor 61. The inverter unit 170 is formed in a plate shape overall. The inverter unit 170 extends in a direction perpendicular to the axial direction AD.

[0031] The motor device 60 and the inverter device 80 are arranged side by side in the axial direction AD. For example, the inverter device 80 is provided between the motor device 60 and the propeller 20 in the axial direction AD. The motor shaft 64 is connected to the propeller 20 in a state in which it passes through the inverter device 80 in the axial direction AD.

[0032] As shown in Fig. 2, the inverter device 80 includes an inverter circuit 81, a smoothing capacitor 145, a filter circuit 150, and a control circuit 160. In Fig. 3, the motor 61 is illustrated as MG, the filter circuit 150 as EMI, and the control circuit 160 as CD.

[0033] The propulsion system 30 has a P line 141, an N line 142, and an output line 143. The P line 141 and the N line 142 electrically connect the battery 31 and the inverter circuit 81. The P line 141 and the N line 142 are formed by bus bars, electric wiring, etc. At least a portion of the P line 141 and at least a portion of the N line 142 are included in the inverter device 80.

[0034] The P line 141 is electrically connected to the positive electrode of the battery 31. The N line 142 is electrically connected to the negative electrode of the battery 31. In the battery 31, the positive electrode is a high potential electrode, and the negative electrode is a low potential electrode. The P line 141 and the N line 142 are power lines for supplying power from the battery 31 to the inverter circuit 81. The P line 141 is a high potential power line and may be referred to as a high potential line. The N line 142 is a low potential power line and may be referred to as a low potential line.

[0035] The output line 143 is a power line for supplying power from the inverter circuit 81 to the motor 61. The output line 143 electrically connects the motor 61 and the inverter circuit 81. For example, the output line 143 is electrically connected to the motor stator 62. The output line 143 is formed of a bus bar, electric wiring, or the like. At least a portion of the output line 143 is included in the inverter device 80.

[0036] The smoothing capacitor 145 is a capacitor that smoothes the DC voltage supplied from the battery 31. The smoothing capacitor 145 is connected to the P line 141 and the N line 142 between the battery 31 and the inverter circuit 81. The smoothing capacitor 145 is connected in parallel to the inverter circuit 81.

[0037] The filter circuit 150 is a circuit for reducing noise such as electromagnetic noise. An example of the filter circuit 150 is an EMI filter. The filter circuit 150 is provided between the smoothing capacitor 145 and the battery 31. The filter circuit 150 is connected in parallel to the inverter circuit 81 with respect to the battery 31. The filter circuit 150 has a choke coil and a filter capacitor. An example of the choke coil is a common mode coil or a normal mode coil. An example of the filter capacitor is a Y capacitor or an X capacitor.

[0038] The inverter circuit 81 is a circuit for converting power. The inverter circuit 81 performs power conversion for each of the multiple phases. The inverter circuit 81 converts DC power from the battery 31 into AC power and supplies the AC power to the motor 61. For example, the inverter circuit 81 is a DC-AC conversion circuit.

[0039] The inverter circuit 81 has upper and lower arm circuits 83 for a plurality of phases. For example, the inverter circuit 81 has upper and lower arm circuits 83 for each of the U phase, V phase, and W phase. The upper and lower arm circuit 83 has an upper arm 84 and a lower arm 85. The upper arm 84 and the lower arm 85 are connected in series to the battery 31. The output line 143 is connected between the upper arm 84 and the lower arm 85 in the upper and lower arm circuit 83. The upper arm 84 is connected to the P line 141 and the output line 143. The lower arm 85 is connected to the N line 142 and the output line 143.

[0040] The upper arm 84 and the lower arm 85 have an arm switch 86 and an arm diode 87. The arm switch 86 is formed of a semiconductor switch or the like. A semiconductor switch is a switch that does not have a mechanical contact. The arm switch 86 is a transistor such as a MOSFET or an IGBT. MOSFET is an abbreviation for Metal-Oxide-Semiconductor Field-Effect Transistor. IGBT is an abbreviation for Insulated Gate Bipolar Transistor. The arm switch 86 is a switching element and is capable of converting power by switching. The switching element is a semiconductor element such as a power element. The arm switch 86 is a conversion switch for converting power.

[0041] The arm diode 87 is a freewheeling diode. The arm diode 87 is connected in anti-parallel to the arm switch 86. The arm diode 87 may be a parasitic diode of the arm switch 86, or may be a diode provided separately from the parasitic diode.

[0042] The control circuit 160 performs motor control to control the motor 61. The motor control includes control of the inverter circuit 81. The control circuit 160 is a control device such as an ECU. The control circuit 160 may be called an inverter control unit or a motor control unit. The control circuit 160 is communicatively connected to the inverter circuit 81. The control circuit 160 performs motor control via the inverter circuit 81 by outputting a command signal.

[0043] The inverter device 80 has a drive circuit. The drive circuit is a circuit for driving the inverter circuit 81. The control circuit 160 is communicatively connected to the inverter circuit 81 via the drive circuit. The drive circuit is electrically connected to the arm switch 86. The drive circuit generates a drive voltage in response to a command signal from the control circuit 160. The drive circuit applies the drive voltage to the arm switch 86, thereby driving the arm switch 86.

[0044] In FIG. 3, in the propulsion device 100, a propeller wind Wp is generated as the propeller 20 rotates. The propeller wind Wp flows in the axial direction AD as a whole. The propeller wind Wp is an airflow generated by the flow of gas such as air. The gas that generates the airflow such as the propeller wind Wp is sometimes called a refrigerant. In this embodiment, the propeller wind Wp flows from the propeller 20 toward the EPU 50. In the EPU 50, the propeller wind Wp flows from the inverter device 80 toward the motor device 60. With respect to the propeller wind Wp, the inverter device 80 is located upstream of the motor device 60.

[0045] The motor housing 70 has a motor housing main body 71 and motor fins 72. The motor housing main body 71 and the motor fins 72 are formed from a metal material or the like and have thermal conductivity. The motor housing main body 71 forms the inner and outer surfaces of the motor housing 70. The outer surface of the motor housing main body 71 includes a motor outer peripheral surface 710, a motor upstream surface 711, and a motor downstream surface 712. The motor outer peripheral surface 710 is formed in an annular shape and extends in the axial direction AD. The motor 61 is accommodated on the inner peripheral side of the motor outer peripheral surface 710.

[0046] The motor upstream surface 711 and the motor downstream surface 712 are arranged in the axial direction AD via the motor outer circumferential surface 710. The motor upstream surface 711 and the motor downstream surface 712 extend in a direction perpendicular to the axial direction AD. The motor upstream surface 711 and the motor downstream surface 712 cover the motor 61 from the axial direction AD. With respect to the propeller wind Wp, the motor upstream surface 711 is located upstream of the motor downstream surface 712.

[0047] The motor fins 72 are provided on the outer surface of the motor housing 70. The motor fins 72 are heat dissipation fins for dissipating heat from the motor device 60 to the outside. The motor fins 72 are formed in a plate shape and extend in a direction perpendicular to the circumferential direction CD. The motor fins 72 are provided on the motor outer peripheral surface 710. The motor fins 72 extend from the motor outer peripheral surface 710 toward the outer periphery. The motor fins 72 extend in the axial direction AD along the motor outer peripheral surface 710. A plurality of the motor fins 72 are arranged in the circumferential direction CD along the motor outer peripheral surface 710. A plurality of the motor fins 72 are arranged in the axial direction AD along the motor outer peripheral surface 710. In addition, a plurality of the motor fins 72 are arranged in the axial direction AD along the motor outer peripheral surface 710.

[0048] As shown in FIG. 3 and FIG. 6, the inverter housing 90 has an inverter housing main body 91 and inverter fins 92. The inverter housing main body 91 and the inverter fins 92 are formed of a metal material or the like and have thermal conductivity. The inverter housing main body 91 forms the inner surface and the outer surface of the inverter housing 90. The outer surface of the inverter housing main body 91 includes an inverter outer peripheral surface 910, an inverter upstream surface 911, an inverter downstream surface 912, and an inverter inner peripheral surface 913. The inverter outer peripheral surface 910 and the inverter inner peripheral surface 913 are formed in an annular shape and extend in the axial direction AD. The inverter housing 90 corresponds to a housing. The inverter outer peripheral surface 910 corresponds to the housing outer peripheral surface. The inverter inner peripheral surface 913 corresponds to the housing inner peripheral surface. Note that in FIG. 6, the motor housing 70 and the like are omitted from the illustration.

[0049] The inverter outer peripheral surface 910 has an outer peripheral upstream end 910a and an outer peripheral downstream end 910b as a pair of ends aligned in the axial direction AD. The outer peripheral upstream end 910a is the end of the pair of ends on the inverter upstream surface 911 side on the inverter outer peripheral surface 910. The outer peripheral upstream end 910a extends in the circumferential direction CD along the outer peripheral edge of the inverter upstream surface 911. The outer peripheral upstream end 910a corresponds to the first surface end. The outer peripheral downstream end 910b is the end of the pair of ends on the inverter outer peripheral surface 910 on the inverter downstream surface 912 side. The outer peripheral downstream end 910b extends in the circumferential direction CD along the outer peripheral edge of the inverter downstream surface 912. The outer peripheral downstream end 910b corresponds to the second surface end.

[0050] The inverter upstream surface 911 and the inverter downstream surface 912 are arranged in the axial direction AD via the inverter outer peripheral surface 910. The inverter upstream surface 911 and the inverter downstream surface 912 extend in a direction perpendicular to the axial direction AD. The inverter upstream surface 911 and the inverter downstream surface 912 cover the inverter unit 170 from the axial direction AD. The inverter upstream surface 911 corresponds to a housing cover surface. With respect to the propeller wind Wp, the inverter upstream surface 911 is located upstream of the inverter downstream surface 912.

[0051] In the EPU 50, the motor upstream surface 711 and the inverter downstream surface 912 are overlapped. In the EPU 50, the motor outer peripheral surface 710 and the inverter outer peripheral surface 910 are arranged in the axial direction AD. With respect to the propeller wind Wp, the inverter upstream surface 911 is provided upstream of the motor downstream surface 712.

[0052] The inverter housing main body 91 has an inverter outer peripheral wall 95, an inverter upstream wall 96, and an inverter downstream wall 97. The inverter outer peripheral wall 95 forms an inverter outer peripheral surface 910 and an inverter inner peripheral surface 913. The inverter outer peripheral surface 910 is the outer peripheral surface of the inverter outer peripheral wall 95. The inverter inner peripheral surface 913 is the inner peripheral surface of the inverter outer peripheral wall 95. The inverter outer peripheral wall 95 is formed in a cylindrical shape and extends in the axial direction AD. The inverter section 170 is accommodated on the inner peripheral side of the inverter outer peripheral wall 95.

[0053] The inverter upstream wall 96 forms an inverter upstream surface 911. The inverter upstream surface 911 is the outer surface of the inverter upstream wall 96. The inverter downstream wall 97 forms an inverter downstream surface 912. The inverter downstream surface 912 is the outer surface of the inverter downstream wall 97. The inverter upstream wall 96 and the inverter downstream wall 97 are arranged in the axial direction AD via the inverter outer peripheral wall 95. The inverter upstream wall 96 and the inverter downstream wall 97 extend in a direction perpendicular to the axial direction AD. The inverter upstream wall 96 and the inverter downstream wall 97 are in a state of covering the inverter section 170 from the axial direction AD. The inverter upstream wall 96 and the inverter downstream wall 97 are in a state of closing the inner space of the inverter outer peripheral wall 95 from the axial direction AD. With respect to the propeller wind Wp, the inverter upstream wall 96 is upstream of the inverter downstream wall 97.

[0054] 5 and 6, the inverter unit 170 forms the inverter circuit 81, the smoothing capacitor 145, the filter circuit 150, the control circuit 160, and the like. The inverter unit 170 has an inverter board 171, a switch component 175, a capacitor component 176, and a filter component 177. The inverter board 171 is a circuit board. The inverter board 171 extends in a direction perpendicular to the axial direction AD along the inverter upstream wall 96 and the inverter downstream wall 97. The inverter board 171 is provided between the inverter upstream wall 96 and the inverter downstream wall 97. In the axial direction AD, the distance between the inverter board 171 and the outer peripheral upstream wall 96a is greater than the distance between the inverter board 171 and the inner peripheral upstream wall 96b.

[0055] The switch component 175, the capacitor component 176, and the filter component 177 are electric or electronic components. The components 175-177 are mounted on the inverter board 171. The components 175-177 protrude from the inverter board 171 toward the inverter upstream wall 96. At least a portion of each of the components 175-177 is provided between the inverter board 171 and the inverter upstream wall 96. Note that in FIG. 6, the capacitor component 176, the filter component 177, and the like are not shown.

[0056] The switch component 175 is a component that forms the arm switch 86. The capacitor component 176 is a component that forms the smoothing capacitor 145. The filter component 177 is a component for forming the filter circuit 150. The filter component 177 may be a component that forms a choke coil, a component that forms a filter capacitor, or the like. The capacitor component 176 may be a component that forms a filter capacitor.

[0057] A plurality of switch parts 175 are arranged in the circumferential direction CD along the inverter inner peripheral surface 913. The switch parts 175 are provided on the inverter inner peripheral surface 913. The switch parts 175 correspond to surface-mounted parts. The switch parts 175 are fixed to at least one of the inverter board 171 and the inverter inner peripheral surface 913. The switch parts 175 are provided on the inverter inner peripheral surface 913 in a state in which heat is transferred from the switch parts 175 to the inverter outer peripheral wall 95. For example, the switch parts 175 are fixed to the inverter outer peripheral wall 95 with a fixing tool such as a screw in a state in which the switch parts 175 are in contact with the inverter inner peripheral surface 913. The switch parts 175 may be provided on the inverter inner peripheral surface 913 via a heat transfer gel or a fixing member.

[0058] The switch component 175 is provided between the outer periphery upstream end 910a and the outer periphery downstream end 910b in the axial direction AD. The switch component 175 is provided at a position away from both the inverter upstream wall 96 and the inverter downstream wall 97. The switch component 175 is provided at a position where the outer periphery center line Crd passes through. For example, the outer periphery center line Crd passes through the center of the switch component 175. The outer periphery center line Crd is a center line that passes through the center of the inverter outer periphery surface 910 in the axial direction AD. The outer periphery center line Crd passes through the middle between the outer periphery upstream end 910a and the outer periphery downstream end 910b. The outer periphery center line Crd is a virtual line that extends in a straight line. The outer periphery center line Crd is perpendicular to the motor axis line Cm.

[0059] The capacitor component 176 and the filter component 177 are provided on the inner circumferential side of the switch component 175. For example, the capacitor component 176 and the filter component 177 are provided at a position spaced away from the switch component 175 on the inner circumferential side. The capacitor component 176 and the filter component 177 correspond to inner circumferential components. The capacitor component 176 and the filter component 177 are provided at a position spaced away from the motor shaft 64 on the outer circumferential side.

[0060] In the EPU 50, the motor device 60 and the inverter device 80 generate heat as the motor 61 is driven. In the motor device 60, the motor 61 and other components generate heat as current is passed through the motor 61. In the inverter device 80, the inverter unit 170 and other components generate heat as current is passed through the inverter unit 170. For example, in the inverter device 80, the switch component 175, capacitor component 176, filter component 177, and other components generate heat as current is passed through the arm switch 86, smoothing capacitor 145, and filter circuit 150. The inverter unit 170 corresponds to a heat-generating component. The switch component 175, capacitor component 176, and filter component 177 correspond to heat-generating components.

[0061] The control circuit 160 and the drive circuit may be formed by the inverter board 171, or may be formed by another circuit board different from the inverter board 171. For example, the other circuit board is accommodated in the inverter housing 90 together with the inverter board 171, for example, by being arranged on the inverter board 171 in the axial direction AD.

[0062] As shown in Figs. 3 and 6, the inverter fins 92 are provided on the outer surface of the inverter housing 90. The inverter fins 92 are heat dissipation fins for dissipating heat from the inverter device 80 to the outside. The inverter fins 92 are formed in a plate shape and extend in a direction perpendicular to the circumferential direction CD. The inverter fins 92 are provided on an inverter outer circumferential surface 910. The inverter fins 92 extend from the inverter outer circumferential surface 910 toward the outer periphery. The inverter fins 92 extend in the axial direction AD along the inverter outer circumferential surface 910. A plurality of the inverter fins 92 are arranged in the circumferential direction CD along the inverter outer circumferential surface 910 (see Figs. 4 and 5). A plurality of the inverter fins 92 are arranged in the axial direction AD along the inverter outer circumferential surface 910. The inverter fins 92 correspond to outer circumferential fins.

[0063] The multiple inverter fins 92 include a first fin 921 and a second fin 922. The first fin 921 and the second fin 922 are included in the inverter housing 90. The first fin 921 and the second fin 922 are arranged in an axial direction AD along the inverter outer peripheral surface 910. The first fin 921 and the second fin 922 are spaced apart in a direction perpendicular to the radial direction RD. For example, the first fin 921 and the second fin 922 are spaced apart in the axial direction AD. The first fin 921 and the second fin 922 are arranged in multiples in the circumferential direction CD along the inverter outer peripheral surface 910.

[0064] The first fin 921 is provided closer to the outer circumferential upstream end 910a than the second fin 922. The first fin 921 is provided between the second fin 922 and the outer circumferential upstream end 910a in the axial direction AD. The first fin 921 is provided closer to the outer circumferential upstream end 910a than the outer circumferential center line Crd. The first fin 921 is sometimes referred to as an upstream fin.

[0065] The second fin 922 is provided between the first fin 921 and the outer circumferential downstream end 910b in the axial direction AD. The second fin 922 is provided closer to the outer circumferential downstream end 910b than the outer circumferential center line Crd. With respect to the propeller wind Wp, the first fin 921 is located upstream of the second fin 922. The second fin 922 is sometimes referred to as a downstream fin.

[0066] 7, the first fin 921 has a pair of first fin surfaces 111. The first fin surface 111 is a plate surface of the first fin 921. The first fin surface 111 extends in a direction perpendicular to the circumferential direction CD. The pair of first fin surfaces 111 are aligned in the circumferential direction CD. The first fin surfaces 111 are also side surfaces of the first fin 921 and may be referred to as fin side surfaces.

[0067] The first fin 921 has a first upstream end 112 and a first downstream end 113 as a pair of ends aligned in the axial direction AD. The first upstream end 112 is the upstream end of the first fin 921. The first upstream end 112 is the end of the pair of ends of the first fin 921 on the outer circumferential upstream end 910a side. The first upstream end 112 has an end face extending in a direction perpendicular to the axial direction AD. The end face of the first upstream end 112 faces the outer circumferential upstream end 910a side. The first downstream end 113 is the downstream end of the first fin 921. The first downstream end 113 is the end of the pair of ends of the first fin 921 on the outer circumferential downstream end 910b side. The first downstream end 113 has an end face extending in a direction perpendicular to the axial direction AD. The end face of the first downstream end 113 faces the outer circumferential downstream end 910b side.

[0068] The first fin 921 has a shape in which the width in the circumferential direction CD gradually expands from the first upstream end 112 toward the first downstream end 113. The first fin 921 corresponds to an expanding fin. The first fin 921 is continuously expanded toward the first downstream end 113. The width dimension W1 of the first fin 921 gradually increases toward the first downstream end 113. The width dimension W1 corresponds to the width. The width dimension W1 is the width of the first fin 921 in the circumferential direction CD. In the first fin 921, the portion where the width dimension W1 is smallest is the first upstream end 112. In the first fin 921, the portion where the width dimension W1 is largest is the first downstream end 113. The width dimension W1b of the first downstream end 113 is larger than the width dimension W1a of the first upstream end 112.

[0069] In the first fin 921, one of the pair of first fin surfaces 111 is inclined relative to the other. At least one of the pair of first fin surfaces 111 is inclined in the circumferential direction CD with respect to the motor axis Cm. For example, one of the pair of first fin surfaces 111 is inclined to one side in the circumferential direction CD with respect to the motor axis Cm. The other of the pair of first fin surfaces 111 is inclined to the other side in the circumferential direction CD with respect to the motor axis Cm. The first fin 921 is formed in a tapered shape. The first fin surface 111 extends straight in the axial direction AD. The first fin surface 111 is a tapered surface.

[0070] Note that first fin 921 may expand stepwise toward first downstream end 113. For example, first fin surface 111 may be a stepped surface. Also, first fin surface 111 may be curved so as to be recessed or bulged in the circumferential direction CD. For example, first fin surface 111 may be a curved surface or a bent surface.

[0071] At least a portion of the first fin 921 is provided at a position aligned with the inverter unit 170 in the radial direction RD. The first fin 921 is provided at a position aligned with the inverter unit 170 in the radial direction RD. The first fin 921 extends from the inverter unit 170 toward only the outer circumferential upstream end 910a out of the outer circumferential upstream end 910a and the outer circumferential downstream end 910b. The first fin 921 corresponds to the first outer circumferential fin.

[0072] For example, at least a portion of the first fin 921 is provided at a position aligned with the switch component 175 in the radial direction RD. The first fin 921 has a first downstream end 113 provided at a position aligned with the switch component 175 in the radial direction RD. The first fin 921 extends from the outer circumferential upstream end 910a and the outer circumferential downstream end 910b only toward the outer circumferential upstream end 910a.

[0073] For two first fins 921 adjacent to each other in the circumferential direction CD, the first interval D1 gradually decreases from the first upstream end 112 to the first downstream end 113. The first interval D1 is the distance between the two first fins 921 adjacent to each other in the circumferential direction CD. The first interval D1 continuously decreases from the first upstream end 112 to the first downstream end 113. The first interval D1 includes an upstream end interval D1a and a downstream end interval D1b. The upstream end interval D1a is the distance between the two first upstream ends 112 adjacent to each other in the circumferential direction CD. The downstream end interval D1b is the distance between the first downstream ends 113 adjacent to each other in the circumferential direction CD. The downstream end interval D1b is smaller than the upstream end interval D1a. As for the first fin 921, the width dimension W1 gradually increases from the first upstream end 112 to the first downstream end 113, and therefore the first distance D1 gradually decreases from the first upstream end 112 to the first downstream end 113.

[0074] The second fin 922 has a pair of second fin surfaces 121. The second fin surfaces 121 are plate surfaces of the second fin 922. The second fin surfaces 121 extend in a direction perpendicular to the circumferential direction CD. The pair of second fin surfaces 121 are aligned in the circumferential direction CD. The second fin surfaces 121 are also side surfaces of the second fin 922 and may be referred to as fin side surfaces.

[0075] The second fin 922 has a second upstream end 122 and a second downstream end 123 as a pair of ends aligned in the axial direction AD. The second upstream end 122 is the upstream end of the second fin 922. The second upstream end 122 is the end of the pair of ends of the second fin 922 on the outer circumferential upstream end 910a side. The second upstream end 122 has an end face extending in a direction perpendicular to the axial direction AD. The end face of the second upstream end 122 faces the outer circumferential upstream end 910a side. The second downstream end 123 is the downstream end of the second fin 922. The second downstream end 123 is the end of the pair of ends of the second fin 922 on the outer circumferential downstream end 910b side. The second downstream end 123 has an end face extending in a direction perpendicular to the axial direction AD. The end face of the second downstream end 123 faces the outer circumferential downstream end 910b side.

[0076] The second fin 922 has a shape that is gradually contracted in the circumferential direction CD from the second upstream end 122 toward the second downstream end 123. The second fin 922 is sometimes referred to as a contracted fin. The second fin 922 is continuously contracted toward the second downstream end 123. The width dimension W2 of the second fin 922 gradually decreases toward the second downstream end 123. The width dimension W2 is the width of the second fin 922 in the circumferential direction CD. In the second fin 922, the portion where the width dimension W2 is largest is the second upstream end 122. In the second fin 922, the portion where the width dimension W2 is smallest is the second downstream end 123. The width dimension W2b of the second downstream end 123 is smaller than the width dimension W2a of the second upstream end 122.

[0077] In the second fin 922, one of the pair of second fin surfaces 121 is inclined relative to the other. At least one of the pair of second fin surfaces 121 is inclined in the circumferential direction CD with respect to the motor axis Cm. For example, one of the pair of second fin surfaces 121 is inclined to one side in the circumferential direction CD with respect to the motor axis Cm. The other of the pair of second fin surfaces 121 is inclined to the other side in the circumferential direction CD with respect to the motor axis Cm. The second fin 922 is formed in a tapered shape. The second fin surface 121 extends straight in the axial direction AD. The second fin surface 121 is a tapered surface.

[0078] The second fin 922 may be expanded in stages toward the second downstream end 123. For example, the second fin surface 121 may be a stepped surface. The second fin surface 121 may be curved so as to be recessed or bulged in the circumferential direction CD. For example, the second fin surface 121 may be a curved surface or a bent surface.

[0079] At least a portion of the second fin 922 is provided at a position aligned with the switch component 175 in the radial direction RD. The second fin 922 has a second upstream end 122 provided at a position aligned with the switch component 175 in the radial direction RD. The second fin 922 extends from the first upstream end 112 toward only the outer circumferential downstream end 910b out of the outer circumferential upstream end 910a and the outer circumferential downstream end 910b. The second fin 922 corresponds to the second outer circumferential fin.

[0080] For two second fins 922 adjacent to each other in the circumferential direction CD, the second interval D2 gradually increases from the second upstream end 122 toward the second downstream end 123. The second interval D2 is the distance between two second fins 922 adjacent to each other in the circumferential direction CD. The second interval D2 continuously decreases from the second upstream end 122 toward the second downstream end 123. The second interval D2 includes an upstream end interval D2a and a downstream end interval D2b. The upstream end interval D2a is the distance between the two second upstream ends 122 adjacent to each other in the circumferential direction CD. The downstream end interval D2b is the distance between the two second downstream ends 123 adjacent to each other in the circumferential direction CD. The downstream end interval D2b is larger than the upstream end interval D2a. As for the second fin 922, the width dimension W2 gradually increases from the second upstream end 122 to the second downstream end 123, and therefore the second spacing D2 gradually decreases from the second upstream end 122 to the second downstream end 123.

[0081] In the first fin 921 and the second fin 922, the first downstream end 113 and the second upstream end 122 face each other. The first downstream end 113 and the second upstream end 122 are aligned in the axial direction AD. The first downstream end 113 and the second upstream end 122 are not shifted in the circumferential direction CD. For example, one of the first downstream end 113 and the second upstream end 122 does not protrude further in the circumferential direction CD than the other. In addition, the width dimension W1b of the first downstream end 113 and the width dimension W2a of the second upstream end 122 are the same.

[0082] The third interval D3 is larger than the downstream end interval D1b and the upstream end interval D2a. Moreover, the third interval D3 is smaller than the upstream end interval D1a and the downstream end interval D2b. The third interval D3 is the distance between the first fin 921 and the second fin 922 in the axial direction AD. Note that the third interval D3 may be smaller than or the same as the downstream end interval D1b and the upstream end interval D2a. Moreover, the third interval D3 may be larger than or the same as the upstream end interval D1a and the downstream end interval D2b.

[0083] In the inverter housing 90, a fin flow passage 130 is formed by a plurality of inverter fins 92. The fin flow passage 130 extends along the inverter outer peripheral surface 910 in a direction perpendicular to the radial direction RD. The fin flow passage 130 extends in the axial direction AD and the circumferential direction CD along the outer surfaces of the inverter fins 92. The fin flow passage 130 is open toward the upstream side, the downstream side, and the outer peripheral side. For example, the fin flow passage 130 is open in the axial direction AD toward the outer peripheral upstream end 910a and the outer peripheral downstream end 910b. The fin flow passage 130 is also open toward the opposite side to the inverter outer peripheral surface 910.

[0084] The fin flow passage 130 has a first flow passage 131, a second flow passage 132, and a connecting flow passage 133. The first flow passage 131, the second flow passage 132, and the connecting flow passage 133 are aligned along the inverter outer peripheral surface 910. The first flow passage 131 and the second flow passage 132 are aligned in the axial direction AD. The first flow passage 131 is located closer to the outer peripheral upstream end 910a than the second flow passage 132. The connecting flow passage 133 is provided between the first flow passage 131 and the second flow passage 132 in the axial direction AD. The connecting flow passage 133 connects the first flow passage 131 and the second flow passage 132.

[0085] The first flow passage 131 is a space between two first fins 921 adjacent to each other in the circumferential direction CD. The first flow passage 131 is formed by two first fin surfaces 111 facing each other in the circumferential direction CD. The first flow passage 131 extends in the axial direction AD along the inverter outer circumferential surface 910 and the first fin surfaces 111.

[0086] The first flow passage 131 is open toward the upstream side, downstream side, and outer circumferential side. The first flow passage 131 has a first upstream port 131a and a first downstream port 131b. The first upstream port 131a opens the first flow passage 131 toward the upstream side. The first upstream port 131a is located at a position aligned in the circumferential direction CD at the first upstream end 112. The first downstream port 131b opens the first flow passage 131 toward the downstream side. The first downstream port 131b is located at a position aligned in the circumferential direction CD at the first downstream end 113. The first upstream port 131a and the first downstream port 131b are aligned in the axial direction AD.

[0087] In the circumferential direction CD, the width dimension of the first flow passage 131 is the same as the first interval D1. The width dimension of the first flow passage 131 is maximum at the first upstream port 131a. The width dimension of the first upstream port 131a is the same as the interval D1a. The width dimension of the first flow passage 131 is minimum at the first downstream port 131b. The width dimension of the first downstream port 131b is the same as the interval D1b.

[0088] The cross-sectional area of ​​the first flow path 131 gradually decreases from the first upstream port 131a toward the first downstream port 131b. The cross-sectional area of ​​the first flow path 131 is the area of ​​the first flow path 131 on a surface obtained by cutting the first flow path 131 in a direction perpendicular to the axial direction AD. In the first flow path 131, the first upstream port area S131a is the largest. The first upstream port area S131a is the open area of ​​the first upstream port 131a. The first upstream port area S131a may be referred to as the cross-sectional area of ​​the first upstream port 131a. In the first flow path 131, the first downstream port area S131b is the smallest. The first downstream port area S131b is the open area of ​​the first downstream port 131b. The first downstream port area S131b may be referred to as the cross-sectional area of ​​the first downstream port 131b.

[0089] The second flow passage 132 is a space between two second fins 922 adjacent to each other in the circumferential direction CD. The second flow passage 132 is formed by two second fin surfaces 121 facing each other in the circumferential direction CD. The second flow passage 132 extends in the axial direction AD along the inverter outer circumferential surface 910 and the second fin surfaces 121.

[0090] The second flow passage 132 is open toward the upstream side, downstream side, and outer circumferential side. The second flow passage 132 has a second upstream port 132a and a second downstream port 132b. The second upstream port 132a opens the second flow passage 132 toward the upstream side. The second upstream port 132a is located at a position aligned in the circumferential direction CD at the second upstream end 122. The second downstream port 132b opens the second flow passage 132 toward the downstream side. The second downstream port 132b is located at a position aligned in the circumferential direction CD at the second downstream end 123. The second upstream port 132a and the second downstream port 132b are aligned in the axial direction AD.

[0091] In the circumferential direction CD, the width dimension of the second flow passage 132 is the same as the second interval D2. The width dimension of the second flow passage 132 is smallest at the second upstream port 132a. The width dimension of the second upstream port 132a is the same as the interval D2a. The width dimension of the second flow passage 132 is largest at the second downstream port 132b. The width dimension of the second downstream port 132b is the same as the interval D2b.

[0092] The cross-sectional area of ​​the second flow path 132 gradually increases from the second upstream port 132a toward the second downstream port 132b. The cross-sectional area of ​​the second flow path 132 is the area of ​​the second flow path 132 on a surface obtained by cutting the second flow path 132 in a direction perpendicular to the axial direction AD. In the second flow path 132, the second upstream port area S132a is the smallest. The second upstream port area S132a is the open area of ​​the second upstream port 132a. The second upstream port area S132a may be referred to as the cross-sectional area of ​​the second upstream port 132a. In the second flow path 132, the second downstream port area S132b is the largest. The second downstream port area S132b is the open area of ​​the second downstream port 132b. The second downstream port area S132b may be referred to as the cross-sectional area of ​​the second downstream port 132b.

[0093] In the first flow passage 131 and the second flow passage 132, the first downstream opening 131b and the second upstream opening 132a are arranged in the axial direction AD. The first downstream opening 131b is open in the axial direction AD toward the outer circumferential downstream end 910b side. The first downstream opening 131b corresponds to the first opposed opening. The second upstream opening 132a is open in the axial direction AD toward the outer circumferential upstream end 910a side. The second upstream opening 132a corresponds to the second opposed opening. The first downstream opening 131b and the second upstream opening 132a are not shifted in the circumferential direction CD. For example, one of the first downstream opening 131b and the second upstream opening 132a does not protrude in the circumferential direction CD more than the other. In addition, the width dimension of the first downstream opening 131b and the width dimension of the second upstream opening 132a are the same. In addition, the first downstream opening area S131b and the second upstream opening area S132a are the same.

[0094] The first upstream opening 131a and the second downstream opening 132b are arranged in the axial direction AD. The first upstream opening 131a and the second downstream opening 132b are not shifted in the circumferential direction CD. For example, one of the first upstream opening 131a and the second downstream opening 132b does not protrude further in the circumferential direction CD than the other. The width dimension of the first upstream opening 131a and the width dimension of the second downstream opening 132b are the same. The first upstream opening area S131a and the second downstream opening area S132b are the same.

[0095] The connection flow passage 133 connects the plurality of first flow passages 131 and the plurality of second flow passages 132. The connection flow passage 133 extends in the circumferential direction CD so as to span the plurality of first flow passages 131. The connection flow passage 133 connects two first flow passages 131 adjacent to each other in the circumferential direction CD. The first downstream port 131b is included in the boundary between the connection flow passage 133 and the first flow passage 131. The connection flow passage 133 extends in the circumferential direction CD so as to span the plurality of second flow passages 132. The connection flow passage 133 connects two second flow passages 132 adjacent to each other in the circumferential direction CD. The second upstream port 132a is included in the boundary between the connection flow passage 133 and the second flow passage 132.

[0096] The connection flow passage 133 is open toward the upstream side, downstream side, and outer periphery side. The connection flow passage 133 includes a space between the first fin 921 and the second fin 922. This space is formed by the first downstream end 113 and the second upstream end 122. The connection flow passage 133 includes a space connecting the first flow passage 131 and the second flow passage 132. In the axial direction AD, the width dimension of the connection flow passage 133 is the same as the third interval D3. The width dimension of the connection flow passage 133 is larger than the width dimension of the first downstream port 131b and the width dimension of the second upstream port 132a. The width dimension of the connection flow passage 133 is smaller than the width dimension of the first upstream port 131a and the width dimension of the second downstream port 132b.

[0097] As shown in FIG. 8, when the propeller wind Wp flows into the fin flow passage 130, the main flow regions R11, R21 and the temperature boundary layers R12, R22 may be formed in the fin flow passage 130. When the inverter housing 90 rises due to heat generated in the inverter section 170, a temperature difference is likely to occur between the propeller wind Wp that flows into the fin flow passage 130 and the inverter fins 92. The main flow regions R11, R21 are regions where the propeller wind Wp, which has a temperature difference with the inverter fins 92, is likely to flow. The temperature boundary layers R12, R22 are regions where the temperature of the propeller wind Wp is likely to change due to heat from the inverter fins 92. The temperature boundary layers R12, R22 are formed so as to extend in layers along the outer surface of the inverter fins 92. The temperature boundary layers R12, R22 are sometimes referred to as temperature boundary regions. The main flow regions R11, R21 are sometimes referred to as main flow temperature regions.

[0098] The propeller wind Wp includes a first propeller wind Wp1. The first propeller wind Wp1 is the propeller wind Wp flowing through the first passage 131. The first propeller wind Wp1 flows into the first passage 131 from the first upstream port 131a. The first propeller wind Wp1 flows through the first passage 131 in the axial direction AD.

[0099] In the first flow passage 131, the first propeller wind Wp1 flows, and thus a first mainstream region R11 and a first temperature boundary layer R12 may be formed. The first temperature boundary layer R12 is formed so as to extend in a layered manner in the axial direction AD along the first fin surface 111. For example, in the first temperature boundary layer R12, the thickness in the circumferential direction CD gradually increases from the first upstream port 131a to the first downstream port 131b. The first mainstream region R11 is on the opposite side to the first fin 921 in the circumferential direction CD via the first temperature boundary layer R12. The first mainstream region R11 is formed between two first temperature boundary layers R12 adjacent to each other in the circumferential direction CD. For example, in the first mainstream region R11, the width in the circumferential direction CD gradually decreases from the first upstream port 131a to the first downstream port 131b.

[0100] As shown in FIG. 9, the first propeller wind Wp1 includes a first mainstream wind Wp11 and a first boundary wind Wp12. The first mainstream wind Wp11 flows in the axial direction AD through the first mainstream region R11 toward the first downstream port 131b. The first boundary wind Wp12 flows in the axial direction AD through the first temperature boundary layer R12 toward the first downstream port 131b. The temperature of the first boundary wind Wp12 is likely to increase in the first temperature boundary layer R12. The temperature of the first boundary wind Wp12 is likely to be higher than the temperature of the first mainstream wind Wp11. That is, a temperature difference is likely to occur between the first boundary wind Wp12 and the first mainstream wind Wp11.

[0101] 8, the propeller wind Wp includes a second propeller wind Wp2. The second propeller wind Wp2 is the propeller wind Wp flowing through the second passage 132. The second propeller wind Wp2 flows into the second passage 132 from the second upstream port 132a. The second propeller wind Wp2 flows through the second passage 132 in the axial direction AD.

[0102] In the second flow passage 132, the second propeller wind Wp2 flows, and thus a second mainstream region R21 and a second temperature boundary layer R22 may be formed. The second temperature boundary layer R22 is formed so as to extend in a layered manner in the axial direction AD along the second fin surface 121. For example, the thickness of the second temperature boundary layer R22 in the circumferential direction CD gradually increases from the second upstream port 132a to the second downstream port 132b. The second mainstream region R21 is on the opposite side to the second fin 922 in the circumferential direction CD via the second temperature boundary layer R22. The second mainstream region R21 is a space between two second temperature boundary layers R22 adjacent to each other in the circumferential direction CD.

[0103] As shown in FIG. 9, the second propeller wind Wp2 includes a second mainstream wind Wp21 and a second boundary wind Wp22. The second mainstream wind Wp21 flows in the axial direction AD through the second mainstream region R21 toward the second downstream port 132b. The second boundary wind Wp22 flows in the axial direction AD through the second temperature boundary layer R22 toward the second downstream port 132b. The second boundary wind Wp22 is likely to increase in temperature in the second temperature boundary layer R22. The temperature of the second boundary wind Wp22 is likely to be higher than the temperature of the second mainstream wind Wp21. That is, a temperature difference is likely to occur between the second boundary wind Wp22 and the second mainstream wind Wp21.

[0104] For example, assume Comparative Example 1 in which the first boundary wind Wp12, which had been flowing through the first temperature boundary layer R12, continues to flow in the axial direction AD and flows through the second temperature boundary layer R22 as the second boundary wind Wp22 because no turbulence such as a vortex occurs in the propeller wind Wp in the fin flow passage 130. In Comparative Example 1, the temperature of the first boundary wind Wp12 further increases in the second temperature boundary layer R22 as the second boundary wind Wp22. For this reason, the temperature difference between the second boundary wind Wp22 and the second mainstream wind Wp21 is likely to be larger than the temperature difference between the first boundary wind Wp12 and the first mainstream wind Wp11. In this case, the second temperature boundary layer R22 is likely to become thicker in the circumferential direction CD. Also, in this case, the second mainstream region R21 is likely to become thinner in the circumferential direction CD. Therefore, in the second flow passage 132, there is a concern that the heat dissipation effect of the second fin 922 due to the second boundary wind Wp22 will decrease due to the high temperature of the second boundary wind Wp22.

[0105] In contrast, in this embodiment, the connection flow path 133 is provided between the first flow path 131 and the second flow path 132, so that the propeller wind Wp is easily disturbed. For example, when the first propeller wind Wp1 flows into the connection flow path 133 from the first downstream port 131b, the first propeller wind Wp1 is easily disturbed by being separated from the first downstream end 113. In this case, the first mainstream wind Wp11 and the first boundary wind Wp12 flow into the connection flow path 133 as the first propeller wind Wp1. The first mainstream wind Wp11 and the first boundary wind Wp12 are easily stirred by the disturbance that occurs when they flow into the connection flow path 133.

[0106] Regarding the connection flow passage 133, the width dimension of the first downstream port 131b, the width dimension of the second upstream port 132a, the width dimension of the connection flow passage 133, and the like are set to values ​​that make it easy to stir the first propeller wind Wp1 that flows into the connection flow passage 133. For example, if the width dimension of the connection flow passage 133 is too small, the first propeller wind Wp1 that flows into the connection flow passage 133 may not be stirred easily. That is, the amount of stirring of the first propeller wind Wp1 may be insufficient. If the width dimension of the connection flow passage 133 is appropriately large, the first propeller wind Wp1 that flows into the connection flow passage 133 is easily stirred. That is, the amount of stirring of the first propeller wind Wp1 is unlikely to be insufficient. In addition, the width dimension W1b of the first downstream end 113, the width dimension W2a of the second upstream end 122, the shape and size of the first fin 921, and the shape and size of the second fin 922 are also set so as to make it easier to stir the first propeller wind Wp1 that flows into the connecting flow path 133.

[0107] The propeller wind Wp includes a third propeller wind Wp3. The third propeller wind Wp3 is the propeller wind Wp that flows through the connection flow path 133. The third propeller wind Wp3 includes the first propeller wind Wp1 that flows from the first flow path 131 into the connection flow path 133. That is, the third propeller wind Wp3 includes the first mainstream wind Wp11 and the first boundary wind Wp12. In the third propeller wind Wp3, the first mainstream wind Wp11 and the first boundary wind Wp12 are easily mixed. Therefore, in the connection flow path 133, the temperature of the third propeller wind Wp3 is easily uniform.

[0108] The third propeller wind Wp3 flows from the connection flow path 133 into the second flow path 132, and thus flows through the second flow path 132 as the second propeller wind Wp2. The third propeller wind Wp3 that flows into the second mainstream region R21 flows through the second mainstream region R21 as the second mainstream wind Wp21. The third propeller wind Wp3 that flows into the second temperature boundary layer R22 flows through the second temperature boundary layer R22 as the second boundary wind Wp22. As described above, since the temperature of the third propeller wind Wp3 is uniformized, the temperature of the second mainstream wind Wp21 that flows into the second mainstream region R21 and the temperature of the second boundary wind Wp22 that flows into the second temperature boundary layer R22 are substantially the same.

[0109] For this reason, in this embodiment, the temperature of the second boundary air Wp22 is likely to be lower than in Comparative Example 1. In this case, the second temperature boundary layer R22 is likely to be thinner in the circumferential direction CD than in Comparative Example 1. Also, in this case, the second mainstream region R21 is likely to be thicker in the circumferential direction CD than in Comparative Example 1. Therefore, the heat dissipation effect of the second fin 922 by the second boundary air Wp22 is improved compared to Comparative Example 1.

[0110] Next, consider Comparative Example 2 in which the fin flow path 130 does not have the second flow path 132 and the connecting flow path 133. In Comparative Example 2, as shown in FIG. 10, a comparative fin 921ex is provided on the inverter outer peripheral surface 910 as the inverter fin 92. The comparative fin 921ex extends so as to straddle the inverter section 170 in the axial direction AD. In Comparative Example 2, a comparative flow path 130ex is formed by two comparative fins 921ex adjacent to each other in the circumferential direction CD. The comparative flow path 130ex does not include a flow path corresponding to the connecting flow path 133.

[0111] In the comparative flow path 130ex, the comparative wind Wpex flows in the axial direction AD along the comparative fin 921ex. In the comparative flow path 130ex, the comparative wind Wpex flows to form a comparative mainstream region Rex1 and a comparative temperature boundary layer Rex2. As shown in FIG. 11, the comparative wind Wpex includes a comparative mainstream wind Wpex1 and a comparative boundary wind Wpex2. The comparative mainstream wind Wpex1 flows through the comparative mainstream region Rex1. The comparative boundary wind Wpex2 flows through the comparative temperature boundary layer Rex2.

[0112] In the comparative flow path 130ex, the comparative mainstream wind Wpex1 and the comparative boundary wind Wpex2 are not easily mixed until the comparative wind Wpex flowing in from the upstream side flows out to the downstream side. Therefore, in the comparative flow path 130ex, the temperature difference between the comparative mainstream wind Wpex1 and the comparative boundary wind Wpex2 is likely to increase as the comparative wind Wpex advances downstream. Therefore, in the comparative example 2, there is a concern that the heat dissipation effect of the comparative fins 921ex due to the comparative wind Wpex will be insufficient toward the downstream side of the comparative flow path 130ex. There is also a concern that the heat dissipation effect of the inverter unit 170 due to the comparative wind Wpex will be insufficient.

[0113] The inverter fins 92 of this embodiment will be described below. There is a high demand for weight reduction in the eVTOL 10, which is an electric vertical take-off and landing aircraft. Therefore, the weight of the EPU 50 is reduced by reducing the size of the housing such as the inverter housing 90 and reducing the number of semiconductor elements such as the arm switch 86 connected in parallel. In order to reduce the weight of the EPU 50, it is preferable to apply a cooling structure with low airflow pressure loss and high cooling performance to the air-cooled housing.

[0114] Furthermore, the EPU 50, which is an electric propulsion unit, is a product made up of a motor 61 that drives the propeller 20 and an inverter unit 170 that drives the motor 61. The motor 61 and the inverter unit 170 generate loss and heat when they are driven, and therefore need to be cooled. In the eVTOL 10, in order to reduce the weight of the EPU 50, the EPU 50 is generally cooled by air cooling. Specifically, the air flow generated by the propeller 20 or the air flow generated by a fan separate from the propeller 20 passes between heat dissipation fins installed on the outer surface of the housing of the EPU 50, thereby dissipating heat from the EPU 50.

[0115] In the inverter device 80 mounted on the eVTOL 10, heat-generating components such as the switch component 175 may be arranged in one location relative to the main flow direction of air currents such as the propeller wind Wp. Also, in the inverter device 80, the thermal diffusivity may be low due to the thin thickness of the housing. In response to these issues, it has been found that the performance of the EPU 50 is more likely to be improved by improving the local cooling performance of the housing, rather than increasing the surface area of ​​heat dissipation fins such as the inverter fins 92 to improve the heat dissipation performance of the housing.

[0116] In contrast, in this embodiment, the inverter fins 92 are provided in the inverter housing 90 in a state in which they are divided into a plurality of parts in the axial direction AD. That is, the inverter fins 92 are configured to be divided into a first fin 921 and a second fin 922. With this configuration, the airflow is disturbed in the space between the first fin 921 and the second fin 922, so that the airflow with a higher temperature flowing near the first fin 921 and the airflow with a lower temperature flowing away from the first fin 921 are likely to be mixed. This makes it easier for the temperature of the airflow flowing near the second fin 922 to decrease. That is, the second temperature boundary layer R22 formed along the second fin 922 is likely to become thinner. Therefore, the cooling performance of the second fin 922 is improved.

[0117] Furthermore, with this configuration, because the first fin 921 and the second fin 922 are separated, it is possible to provide a non-installation area where no heat dissipation fins are installed between the first fin 921 and the second fin 922. As a result, the mass of the inverter fins 92 is reduced by the amount of the non-installation area, and the weight of the EPU 50 can be reduced.

[0118] Furthermore, the first fin 921 has a tapered shape so that the area of ​​the first flow passage 131 becomes smaller toward the heat generating element of the inverter unit 170. According to this configuration, the first propeller wind Wp1 flows faster in the first flow passage 131 closer to the first downstream port 131b. That is, in the first flow passage 131, the flow rate of the first propeller wind Wp1 is more likely to increase in the position closer to the inverter unit 170. When the flow rate of the first propeller wind Wp1 increases in this way, the heat transfer coefficient related to the first flow passage 131 is more likely to increase. Therefore, the heat dissipation performance of the inverter housing 90 by the first propeller wind Wp1 can be improved. In addition, the heat transfer coefficient of the first flow passage 131 can be increased, thereby improving the thermal conductance.

[0119] Moreover, with this configuration, due to the high flow velocity of the first propeller wind Wp1 flowing from the first flow passage 131 into the connecting flow passage 133, the first mainstream wind Wp11 and the first boundary wind Wp12 are likely to mix in the connecting flow passage 133. In this way, the first flow passage 131 becomes narrower as it approaches the connecting flow passage 133, so that a configuration in which the third propeller wind Wp3 is likely to be mixed in the connecting flow passage 133 can be realized.

[0120] Furthermore, with this configuration, the flow speed of the first propeller wind Wp1 tends to be faster in the first flow passage 131 closer to the inverter unit 170. For this reason, the heat transfer coefficient of the first propeller wind Wp1 increases, and the heat of the inverter unit 170 tends to be released from the inverter outer peripheral wall 95 and the first fin 921 to the first propeller wind Wp1. Therefore, the heat dissipation performance of the heat generating unit by the first propeller wind Wp1 can be improved.

[0121] According to the present embodiment described so far, the first fin 921 and the second fin 922 are provided at positions spaced apart in a direction perpendicular to the axial direction AD. In this configuration, turbulence such as a vortex is likely to occur in the propeller wind Wp flowing through the space between the first fin 921 and the second fin 922 at a position aligned with the inverter unit 170 in the radial direction RD. For this reason, heat from the inverter unit 170 is likely to be released to the outside of the inverter housing 90 through the first fin 921, the second fin 922, and the inverter outer peripheral wall 95. That is, the heat dissipation effect of the first fin 921, the second fin 922, and the inverter outer peripheral surface 910 can be improved by utilizing the turbulence of the propeller wind Wp. In this way, by locally generating turbulence in the propeller wind Wp at a position aligned with the inverter unit 170 in the radial direction RD on the outside of the inverter housing 90, it is possible to suppress an increase in pressure loss in the entire fin flow path 130. Therefore, it is possible to enhance the heat dissipation effect of the inverter unit 170 by the propeller wind Wp while suppressing a shortage in the amount of the propeller wind Wp flowing through the fin flow passages 130. As described above, in the EPU 50, the inverter fins 92 can enhance the heat dissipation effect of the inverter housing 90.

[0122] According to this embodiment, the first interval D1 between two first fins 921 adjacent to each other in the circumferential direction CD gradually decreases toward the outer circumferential downstream end 910b. In this configuration, the width dimension of the first flow passage 131 decreases toward the inverter unit 170. Therefore, in the first flow passage 131, the flow speed of the first propeller wind Wp1 tends to be faster toward the inverter unit 170. Therefore, the cooling effect of the first propeller wind Wp1 can be locally increased at a position overlapping the inverter unit 170 in the axial direction AD.

[0123] According to this embodiment, the first fin 921 has a width dimension W1 in the circumferential direction CD that gradually increases toward the outer circumferential downstream end 910b. That is, the first fin 921 is an extended fin. This makes it possible to realize a configuration in which the width dimension of the first flow passage 131 decreases toward the outer circumferential downstream end 910b. That is, it is possible to realize a configuration in which the cooling effect of the first propeller wind Wp1 is locally increased with respect to the installation position of the inverter unit 170.

[0124] According to this embodiment, in the fin flow passage 130, the first downstream opening 131b and the second upstream opening 132a are arranged in the axial direction AD. In this configuration, the propeller wind Wp flowing from the first downstream opening 131b into the connection flow passage 133 is likely to be disturbed, while the propeller wind Wp flowing from the first downstream opening 131b into the connection flow passage 133 is likely to flow out from the second upstream opening 132a. Therefore, in the connection flow passage 133, the cooling effect of the inverter unit 170 is improved due to the disturbance of the propeller wind Wp, while the pressure loss in the fin flow passage 130 is prevented from excessively increasing due to the presence of the connection flow passage 133. Therefore, the heat dissipation effect of the inverter housing 90 can be improved by both the disturbance generated in the propeller wind Wp and the high speed of the propeller wind Wp.

[0125] According to the present embodiment, the switch component 175 is provided on the inverter inner circumferential surface 913. The first fin 921 and the second fin 922 extend from a position aligned in the radial direction RD on the switch component 175 toward the axial direction AD. In this configuration, a connection flow path 133, which is a space between the first fin 921 and the second fin 922, is provided at a position aligned in the radial direction RD on the switch component 175. Therefore, in the connection flow path 133, the effect of improving the cooling performance by locally generating turbulence in the propeller wind Wp can be imparted to the switch component 175.

[0126] According to the present embodiment, the inverter section 170 is housed as a heat generating section in the inverter housing 90. In this configuration, the inverter fins 92 can prevent the temperature of the inverter device 80 from excessively increasing due to heat generated by the inverter section 170.

[0127] According to this embodiment, the EPU 50 is driven to fly the eVTOL 10. In this configuration, when the eVTOL 10 is flying due to the drive of the EPU 50, the inverter fins 92 can suppress an excessive rise in temperature of the EPU 50 due to insufficient heat dissipation effect of the inverter housing 90. Therefore, the inverter fins 92 can improve the safety of the eVTOL 10.

[0128] <Second embodiment> In the first embodiment, the width dimension W1b of the first downstream end 113 and the width dimension W2a of the second upstream end 122 are the same. In contrast, in the second embodiment, the width dimension W2a of the second upstream end 122 is larger than the width dimension W1b of the first downstream end 113. The configurations, actions, and effects of the second embodiment that are not particularly described are the same as those of the first embodiment. The second embodiment will be described mainly with respect to the differences from the first embodiment.

[0129] As shown in FIG. 12, in this embodiment, the second outer circumferential fin is a parallel fin. The inverter fins 92 include a second parallel fin 922A as the second outer circumferential fin. The second parallel fin 922A has a different shape from the second fin 922 of the first embodiment. In the second parallel fin 922A, a pair of second fin surfaces 121 extend parallel to the axial direction AD. The pair of second fin surfaces 121 extend parallel to the motor axis Cm. In the second parallel fin 922A, the width dimension W2 is uniform. For example, in the second parallel fin 922A, the width dimension W2a of the second upstream end 122 and the width dimension W2b of the second downstream end 123 are the same. The second parallel fin 922A is sometimes referred to as a parallel fin or a straight fin.

[0130] The second interval D2 is uniform between two second parallel fins 922A adjacent to each other in the circumferential direction CD. For example, the upstream end interval D2a and the downstream end interval D2b are the same between two second parallel fins 922A adjacent to each other in the circumferential direction CD. The width of the second flow passage 132 is uniform. For example, the width of the second upstream port 132a and the width of the second downstream port 132b are the same. The cross-sectional area of ​​the second flow passage 132 is uniform. For example, the second upstream port area S132a and the second downstream port area S132b are the same.

[0131] The first downstream end 113 and the second upstream end 122 are offset in the circumferential direction CD due to their different width dimensions in the circumferential direction CD. For example, the width dimension W1b of the first downstream end 113 is different from the width dimension W2a of the second upstream end 122. The first downstream end 113 protrudes from the second upstream end 122 on at least one side in the circumferential direction CD. For example, the first downstream end 113 protrudes from the second upstream end 122 on both sides in the circumferential direction CD. The first downstream end 113 protrudes from the second upstream end 122 on both sides in the circumferential direction CD. The first downstream end 113 corresponds to a first opposing end. The second upstream end 122 corresponds to a second opposing end.

[0132] The width dimension of the first downstream port 131b and the width dimension of the second upstream port 132a are different. For example, the width dimension of the second upstream port 132a is larger than the width dimension of the first downstream port 131b. The first downstream port area S131b and the second upstream port area S132a are different. For example, the second upstream port area S132a is larger than the first downstream port area S131b.

[0133] The second parallel fins 922A will be described below. In the EPU 50 mounted on the eVTOL 10, in addition to the heat dissipation performance, the pressure loss of the refrigerant flowing between the heat dissipation fins is also an important performance. In contrast, in the second parallel fins 922A, the second upstream end 122 is thinner in the circumferential direction CD than the first downstream end 113. By thinning the second parallel fins 922A, the cross-sectional area of ​​the second flow passage 132 is increased, thereby improving the pressure loss in the second flow passage 132. In addition, the two second fin surfaces 121 facing each other via the second flow passage 132 extend in parallel in the axial direction AD, thereby improving the pressure loss in the second flow passage 132.

[0134] Of the two heat dissipation fins arranged in the axial direction AD, the first fin 921, which is the upstream heat dissipation fin, is an extended fin, so that the flow speed of the propeller wind Wp flowing through the first flow path 131, which is the upstream flow path, can be increased. And, since the second parallel fin 922A, which is the downstream heat dissipation fin, is thinner than the first fin 921, the propeller wind Wp whose flow speed has been increased by the first fin 921 can generate a fast flow in the fin division section by its inertia. Therefore, the mixing of the propeller wind Wp can be promoted in the fin division section. The fin division section is a portion where the inverter fin 92 is divided. For example, the fin division section is a portion between an upstream fin such as the first fin 921 and a downstream fin such as the second parallel fin 922A.

[0135] Since the second parallel fins 922A are thinner than the first fins 921, the second parallel fins 922A can be made lighter than the first fins 921. In this manner, the fin mass is reduced by the amount that the second parallel fins 922A are made lighter, which can contribute to reducing the weight of the EPU 50 and the inverter housing 90.

[0136] According to this embodiment, the first downstream port 131b and the second upstream port 132a are shifted in the circumferential direction CD. In this configuration, the propeller wind Wp that flows into the connection flow passage 133 from the first downstream port 131b is unlikely to flow out from the connection flow passage 133 to the first upstream port 131a without being stirred. For example, when the propeller wind Wp flows into the connection flow passage 133 from the first downstream port 131b, the propeller wind Wp is likely to be stirred in the connection flow passage 133 because it is likely to peel off from the first downstream end 113. For this reason, a temperature difference is unlikely to occur in the connection flow passage 133. Therefore, it is possible to suppress the heat dissipation effect of the inverter unit 170 due to the propeller wind Wp from varying depending on the part of the inverter unit 170.

[0137] According to this embodiment, the width dimension W2a of the second upstream end 122 is smaller than the width dimension W1b of the first downstream end 113. In this configuration, a configuration in which the second upstream port area S132a is smaller than the first downstream port area S131b can be realized. Therefore, the propeller wind Wp is more likely to flow out from the connection flow passage 133 to the second upstream port 132a. That is, the pressure loss of the propeller wind Wp flowing out from the first downstream port 131b to the second upstream port 132a via the connection flow passage 133 can be reduced.

[0138] <Third embodiment> In the first embodiment, the first flow passage 131 and the second flow passage 132 are aligned in the axial direction AD. In contrast, in the third embodiment, the first flow passage 131 and the second flow passage 132 are formed at positions shifted in the circumferential direction CD. The configurations, actions, and effects of the third embodiment that are not particularly described are similar to those of the first embodiment. The third embodiment will be described mainly with respect to the differences from the first embodiment.

[0139] As shown in Fig. 13, the first fin 921 and the second fin 922 are in a positional relationship in which they are shifted in the circumferential direction CD. That is, the first fin 921 and the second fin 922 are offset in the circumferential direction CD. The first fin 921 is aligned with the second flow passage 132 in the axial direction AD. The second fin 922 is aligned with the first flow passage 131 in the axial direction AD. The first flow passage 131 and the second flow passage 132 are in a positional relationship in which they are spaced apart in the circumferential direction CD. The first downstream port 131b and the second upstream port 132a are spaced apart in the circumferential direction CD. Note that a portion of the first downstream port 131b and a portion of the second upstream port 132a may be aligned in the axial direction AD.

[0140] The first downstream end 113 and the second upstream end 122 are offset in the circumferential direction CD due to different positions in the circumferential direction CD. For example, a part of the first downstream end 113 and a part of the second upstream end 122 are aligned in the axial direction AD. The first downstream end 113 is bridged over two second upstream ends 122 adjacent to each other in the circumferential direction CD. The first downstream end 113 is provided at a position aligned in the axial direction AD at the second upstream port 132a. The second upstream end 122 is provided at a position aligned in the axial direction AD at the first downstream port 131b.

[0141] According to this embodiment, the second upstream end 122 is provided at a position aligned with the first downstream port 131b in the axial direction AD. In this configuration, the propeller wind Wp that flows from the first downstream port 131b into the connecting flow passage 133 advances toward the second upstream end 122. The propeller wind Wp approaches or collides with the second upstream end 122, promoting mixing and stirring of the propeller wind Wp in the connecting flow passage 133. As a result, the temperature of the propeller wind Wp in the connecting flow passage 133 can be made uniform.

[0142] In this embodiment, the width dimension of the connection flow passage 133 may be smaller than the width dimension of the first downstream port 131b or the width dimension of the second upstream port 132a. That is, the cross-sectional area of ​​the connection flow passage 133 may be smaller than the first downstream port area S131b or the second upstream port area S132a. In this configuration, the connection flow passage 133 narrows the fin flow passage 130 more than the first downstream port 131b or the second upstream port 132a. For this reason, in a configuration in which the first downstream end 113 and the second upstream end 122 are offset in the circumferential direction CD, the flow rate of the propeller wind Wp that flows from the first downstream port 131b into the connection flow passage 133 tends to increase when it flows through the connection flow passage 133 in the circumferential direction CD. Therefore, the flow rate of the propeller wind Wp increases at a position aligned with the inverter unit 170 in the radial direction RD, thereby improving the heat dissipation performance of the inverter unit 170 by the propeller wind Wp.

[0143] <Fourth embodiment> In the fourth embodiment, the inverter housing 90 is covered from the outer periphery by a duct member. The configurations, actions, and effects of the fourth embodiment that are not specifically described are the same as those of the third embodiment. The fourth embodiment will be described mainly with respect to the differences from the third embodiment.

[0144] As shown in Fig. 14, the EPU 50 has an outer circumferential duct 200. The outer circumferential duct 200 covers the inverter housing 90 from the outer circumferential side. The outer circumferential duct 200 may be referred to as a duct member or an outer cylinder. The outer circumferential duct 200 has a duct body 201 and duct fins 202. The duct body 201 and the duct fins 202 are formed from a resin material or the like. The duct body 201 and the duct fins 202 have thermal conductivity. The duct body 201 and the duct fins 202 may be formed from a metal material.

[0145] The duct body 201 is formed in a cylindrical shape and extends in the axial direction AD. The duct body 201 extends in the circumferential direction CD so as to be stretched across the inverter fins 92. The duct body 201 is provided on the outer circumferential side of the inverter outer circumferential surface 910 via the inverter fins 92. The duct body 201 is in a state in which it covers the inverter outer circumferential surface 910 from the outer circumferential side. The duct body 201 is provided in a position close to or in contact with the inverter fins 92 in the radial direction RD. The fin flow path 130 is formed between the inverter outer circumferential surface 910 and the duct body 201. The duct body 201 forms the fin flow path 130 between the inverter outer circumferential surface 910 and the inverter outer circumferential surface 910. The duct body 201 corresponds to a duct portion, and the fin flow path 130 corresponds to an outer circumferential flow path.

[0146] The duct main body 201 has a duct outer peripheral surface 201a and a duct inner peripheral surface 201b. The duct outer peripheral surface 201a and the duct inner peripheral surface 201b are formed in an annular shape and extend in the axial direction AD. The duct outer peripheral surface 201a is the outer peripheral surface of the duct main body 201. The duct inner peripheral surface 201b is the inner peripheral surface of the duct main body 201. The duct inner peripheral surface 201b faces the inverter outer peripheral surface 910 via the inverter fin 92. The fin flow path 130 is formed by the duct inner peripheral surface 201b and the inverter outer peripheral surface 910.

[0147] The duct fins 202 are provided on the duct inner peripheral surface 201b. The duct fins 202 are formed in a plate shape and extend in a direction perpendicular to the circumferential direction CD. The duct fins 202 extend from the duct inner peripheral surface 201b toward the inverter outer peripheral surface 910. The duct fins 202 are convex parts that protrude from the duct inner peripheral surface 201b toward the inner peripheral side. The duct fins 202 extend in the axial direction AD along the duct inner peripheral surface 201b. A plurality of duct fins 202 are arranged in the circumferential direction CD along the duct inner peripheral surface 201b.

[0148] At least a portion of the duct fin 202 is provided between two inverter fins 92 adjacent to each other in the circumferential direction CD. The duct fin 202 is disposed between two inverter fins 92 adjacent to each other in the circumferential direction CD from the outer periphery side. In other words, the duct fin 202 is disposed in the fin flow path 130 from the outer periphery side. The duct fins 202 and the inverter fins 92 are arranged alternately in the circumferential direction CD.

[0149] As shown in Figs. 15 to 17, the duct fin 202 has a pair of duct fin surfaces 203. The duct fin surfaces 203 are plate surfaces of the duct fin 202. The pair of duct fin surfaces 203 extend in a direction perpendicular to the circumferential direction CD and are aligned in the circumferential direction CD. The duct fin surfaces 203 are also side surfaces of the duct fin 202 and may be referred to as fin side surfaces. The duct fin surfaces 203 have an upstream fin surface 202a and a downstream fin surface 202b. The upstream fin surface 202a and the downstream fin surface 202b are aligned in the axial direction AD. For example, the upstream fin surface 202a extends upstream from the downstream fin surface 202b.

[0150] The duct fin 202 has a fin upstream end 204 and a fin downstream end 205 as a pair of ends aligned in the axial direction AD. The fin upstream end 204 is the upstream end of the duct fin 202. The fin downstream end 205 is the downstream end of the duct fin 202.

[0151] The duct fin 202 has a shape in which a middle portion in the axial direction AD bulges in the circumferential direction CD. In the circumferential direction CD, the width dimension of the duct fin 202 gradually decreases from the middle portion toward each of the upstream fin end 204 and the downstream fin end 205.

[0152] At least one of the upstream fin surface 202a and the downstream fin surface 202b is inclined in the circumferential direction CD with respect to the motor axis Cm. For example, the upstream fin surface 202a is inclined to one side of the circumferential direction CD with respect to the motor axis Cm. The downstream fin surface 202b is inclined to the other side of the circumferential direction CD with respect to the motor axis Cm. The upstream fin surface 202a and the downstream fin surface 202b extend straight in the axial direction AD. The upstream fin surface 202a and the downstream fin surface 202b are tapered surfaces.

[0153] As shown in FIG. 15, the duct fin 202 has a shape in which the width in the circumferential direction CD gradually shrinks toward the inner periphery. The duct fin 202 corresponds to a tapered fin. The width dimension of the duct fin 202 continuously decreases toward the inverter outer periphery surface 910. The distance between a pair of duct fin surfaces 203 gradually decreases toward the tip of the duct fin 202. The duct fin surfaces 203 are inclined in the circumferential direction CD with respect to the outer periphery center line Crd. The duct fin surfaces 203 extend straight toward the inner periphery. The duct fin surfaces 203 are tapered surfaces.

[0154] The duct fin 202 may be tapered in a stepwise manner toward the inner periphery. For example, the duct fin surface 203 may be a stepped surface. The duct fin surface 203 may be curved so as to be concave or convex in the circumferential direction CD. For example, the duct fin surface 203 may be a curved surface or a bent surface.

[0155] In this embodiment, the inverter fin 92 also has a tapered shape like the duct fin 202. The inverter fin 92 has a shape in which the width in the circumferential direction CD is gradually reduced toward the inner periphery. The first fin surface 111 and the second fin surface 121 are inclined in the circumferential direction CD with respect to the outer periphery center line Crd. The inclination angle of the first fin surface 111 and the second fin surface 121 with respect to the outer periphery center line Crd is the same as the inclination angle of the duct fin surface 203 with respect to the outer periphery center line Crd. In other words, the duct fin surface 203 extends in the radial direction RD parallel to the first fin surface 111 and the second fin surface 121.

[0156] As shown in Fig. 17, the duct fin 202 is provided in the fin flow path 130. At least a portion of the duct fin 202 is provided in the connection flow path 133 between the first downstream port 131b and the second upstream port 132a. The duct fin 202 is in a state of being inserted from the connection flow path 133 into at least one of the first flow path 131 and the second flow path 132. For example, the duct fin 202 extends in the axial direction AD so as to bridge between the first flow path 131 and the second flow path 132 via the connection flow path 133. In the duct fin 202, the fin upstream end 204 is provided in the first flow path 131. The fin downstream end 205 is provided in the second flow path 132.

[0157] The duct fin 202 is interposed at least between two first fins 921 adjacent in the circumferential direction CD and between two second fins 922 adjacent in the circumferential direction CD. For example, the duct fin 202 is provided between two first fins 921 adjacent in the circumferential direction CD, and also between two second fins 922 adjacent in the circumferential direction CD. The duct fin 202 corresponds to a fin interposition portion.

[0158] 16, at least a portion of the duct fins 202 is provided in a position aligned with the inverter unit 170 in the axial direction AD. The duct fins 202 are provided in a position aligned with the switch component 175 in the axial direction AD. For example, the duct fins 202 are provided in a position that does not protrude from the switch component 175 in the axial direction AD. The entire duct fins 202 are aligned with the switch component 175 in the axial direction AD.

[0159] As shown in FIG. 17, in this embodiment, both the first outer circumferential fin and the second outer circumferential fin are parallel fins. The inverter fins 92 include a second parallel fin 922A as the second outer circumferential fin, as in the second embodiment. The inverter fins 92 include a first parallel fin 921A as the first outer circumferential fin. The first parallel fin 921A has a different shape from the first fin 921 of the first embodiment. In the first parallel fin 921A, a pair of first fin surfaces 111 extend parallel to the axial direction AD. The pair of first fin surfaces 111 extend parallel to the motor axis Cm. In the first parallel fin 921A, the width dimension W1 is uniform. For example, in the first parallel fin 921A, the width dimension W1a of the first upstream end 112 and the width dimension W1b of the first downstream end 113 are the same. The first parallel fin 921A is sometimes called a parallel fin or a straight fin.

[0160] The first interval D1 is uniform between two first parallel fins 921A adjacent to each other in the circumferential direction CD. For example, the upstream end interval D1a and the downstream end interval D1b are the same between two first parallel fins 921A adjacent to each other in the circumferential direction CD. The width dimensions of the first flow paths 131 are also uniform. For example, the width dimensions of the first upstream port 131a and the width dimensions of the first downstream port 131b are the same. Furthermore, the cross-sectional areas of the first flow paths 131 are also uniform. For example, the first upstream port area S131a and the first downstream port area S131b are the same.

[0161] In the first flow passage 131, the distance between the first parallel fin 921A and the duct fin 202 in the circumferential direction CD gradually decreases from the fin upstream end 204 toward the first downstream port 131b in the axial direction AD. Therefore, even in a configuration in which two first fin surfaces 111 adjacent in the circumferential direction CD extend in parallel in the axial direction AD, the cross-sectional area of ​​the first flow passage 131 gradually decreases toward the first downstream port 131b. The flow velocity of the first propeller wind Wp1 tends to increase as it passes between the first parallel fin 921A and the duct fin 202 and approaches the first downstream port 131b.

[0162] In the second flow passage 132, the distance between the second parallel fin 922A and the duct fin 202 in the circumferential direction CD gradually increases from the second upstream port 132a toward the fin downstream end 205 in the axial direction AD. For this reason, even in a configuration in which two second fin surfaces 121 adjacent in the circumferential direction CD extend parallel to each other in the axial direction AD, the cross-sectional area of ​​the second flow passage 132 gradually increases toward the fin downstream end 205.

[0163] The outer periphery duct 200 will now be described. By providing the outer periphery duct 200 on the outer periphery side of the inverter housing 90, the propeller wind Wp that flows in the axial direction AD as a refrigerant flow is guided by the outer periphery duct 200. In the inverter device 80, by providing the duct fin 202 between the two heat dissipation fins, the flow path area between the two heat dissipation fins can be reduced without tapering the heat dissipation fins. Therefore, the duct fin 202 can improve the heat dissipation performance around the fin division portion.

[0164] The inverter fins 92 become thinner toward the fin tips. That is, the inverter fins 92 become thinner in the circumferential direction CD the farther they are from the inverter outer peripheral surface 910. For this reason, the first distance D1 and the second distance D2 become larger in a region farther away from the inverter outer peripheral surface 910 toward the outer periphery. In the fin flow path 130, the cross-sectional area of ​​the region far from the inverter outer peripheral surface 910 is larger than the cross-sectional area of ​​the region close to the inverter outer peripheral surface 910.

[0165] In contrast, the duct fin 202 becomes thinner toward the fin tip. That is, the duct fin 202 becomes thinner toward the inverter outer peripheral surface 910. Therefore, in the duct fin 202, the cross-sectional area of ​​the portion far from the inverter outer peripheral surface 910 is larger than the cross-sectional area of ​​the portion close to the inverter outer peripheral surface 910. Therefore, in the actual region in the fin flow path 130 where the propeller wind Wp actually flows, the cross-sectional area of ​​the region far from the inverter outer peripheral surface 910 is reduced to approach the cross-sectional area of ​​the region close to the inverter outer peripheral surface 910 due to the presence of the duct fin 202. This allows a uniform flow to be formed in the fin flow path 130 regardless of the height of the heat dissipation fins such as the inverter fins 92.

[0166] According to this embodiment, at least a portion of the duct fin 202 is provided between the first downstream port 131b and the second upstream port 132a. In this configuration, when the propeller wind Wp flows from the first downstream port 131b into the connection flow passage 133, the propeller wind Wp is likely to be agitated by approaching or colliding with the duct fin 202. Therefore, for the propeller wind Wp, the heat dissipation effect for the inverter unit 170 can be enhanced by disturbances such as vortexes caused by the presence of the duct fin 202.

[0167] According to this embodiment, the duct fins 202 extend in the radial direction RD from the duct body 201 toward the inverter outer peripheral surface 910. In this configuration, the outer peripheral duct 200 is attached to the inverter housing 90, and the duct fins 202 are provided in the fin flow passages 130. Therefore, even if it is difficult to install the duct fins 202 on the inverter outer peripheral surface 910 in the fin flow passages 130 due to reasons such as convenience when manufacturing the inverter housing 90, the duct fins 202 can be arranged. This increases the degree of freedom in the position at which the fin intervening parts such as the duct fins 202 are installed.

[0168] According to this embodiment, the width of the duct fin 202 in the circumferential direction CD gradually decreases toward the inverter outer peripheral surface 910. Therefore, even if the width dimension of the fin flow passage 130 decreases closer to the inverter outer peripheral surface 910, the width dimension of the actual area of ​​the fin flow passage 130 can be made uniform in the radial direction RD.

[0169] <Other embodiments> The disclosure of this specification is not limited to the exemplified embodiments. The disclosure includes the exemplified embodiments and modifications made by those skilled in the art based thereon. For example, the disclosure is not limited to the combination of parts and elements shown in the embodiments, and can be implemented in various modifications. The disclosure can be implemented by various combinations. The disclosure can have additional parts that can be added to the embodiments. The disclosure includes those in which parts and elements of the embodiments are omitted. The disclosure includes the replacement or combination of parts and elements between one embodiment and another embodiment. The disclosed technical scope is not limited to the description of the embodiments. The disclosed technical scope is indicated by the description of the claims, and should be interpreted as including all modifications within the meaning and scope equivalent to the description of the claims.

[0170] In each of the above embodiments, the housing such as the inverter housing 90 may be provided with peripheral fins such as the inverter fins 92 in any manner. At least one of the multiple inverter fins 92 may be provided to correspond to the peripheral fin. The housing may be provided with first peripheral fins such as the first fin 921 and second peripheral fins such as the second fin 922 in any manner. At least one of the multiple first fins 921 may be provided to correspond to the first peripheral fin. At least one of the multiple second fins 922 may be provided to correspond to the second peripheral fin. At least a portion of the peripheral fins, first peripheral fins, and second peripheral fins may be provided on the inverter upstream surface 911 and the inverter downstream surface 912.

[0171] In each of the above embodiments, the first outer circumferential fin and the second outer circumferential fin may have any shape. For example, in the above first embodiment, the first fin 921 may be a contracting fin or a parallel fin. Also, the second fin 922 may be an expanding fin or a parallel fin. Furthermore, the first outer circumferential fins may not have the same shape. Similarly, the second outer circumferential fins may not have the same shape. In addition, the first outer circumferential fin and the second outer circumferential fin may be inclined in the circumferential direction CD with respect to the motor axis Cm.

[0172] In each of the above embodiments, the first outer circumferential fin and the second outer circumferential fin may have any positional relationship as long as they extend in the axial direction AD from a position overlapping with a heat generating portion such as the inverter unit 170 in the radial direction RD. The first outer circumferential fin and the second outer circumferential fin may be separated in a direction perpendicular to the radial direction RD. For example, in the above first embodiment, the first fin 921 and the second fin 922 may be separated in the circumferential direction CD. In this configuration, a part of the first fin 921 and a part of the second fin 922 may be aligned in the circumferential direction CD. For example, the first downstream end 113 may be provided downstream of the second upstream end 122. That is, the first flow path 131 and the second flow path 132 may be directly connected without the connection flow path 133.

[0173] In each of the above embodiments, the size relationship between the width dimension W1b of the first downstream end 113 and the width dimension W2a of the second upstream end 122 may be any. For example, the width dimension W1b of the first downstream end 113 may be larger than the width dimension W2a of the second upstream end 122. In addition, the size relationship between the first downstream opening area S131b and the second upstream opening area S132a may be any. For example, the first downstream opening area S131b may be larger than the second upstream opening area S132a.

[0174] In each of the above embodiments, the fin interposition portion such as the duct fin 202 may have any shape. For example, in the above fourth embodiment, the duct fin 202 may be plate-shaped and extend in the circumferential direction CD. The duct fin 202 may also be formed in a cylindrical, prismatic, or tubular shape.

[0175] In each of the above embodiments, the fin interposition portion may be provided in any manner in the fin flow passage 130. For example, in the above fourth embodiment, the duct fin 202 may be provided on the inverter outer peripheral surface 910. In this configuration, the convex portion provided on the inverter outer peripheral surface 910 is the duct fin 202, which corresponds to the fin interposition portion.

[0176] In each of the above embodiments, the surface-mounted components may be provided in any manner inside the housing. For example, in the above first embodiment, the capacitor component 176 and the filter component 177 may be provided as surface-mounted components. The heat generating portion may not have surface-mounted components. In this configuration, it is preferable that a plurality of heat generating components such as the switch component 175 are arranged along the inverter inner peripheral surface 913.

[0177] In each of the above embodiments, the outer circumferential fins may be motor fins 72. For example, the motor device 60 may be provided upstream of the inverter device 80 with respect to the propeller wind Wp. In this configuration, the motor 61, motor stator 62, motor rotor 63, etc. correspond to the heat generating part, and the motor housing 70 corresponds to the housing. The motor fins 72 are provided on the motor housing 70 so as to become outer circumferential fins.

[0178] In each of the above embodiments, the motor 61 and the inverter unit 170 may be accommodated in a common housing. For example, the common housing is a housing in which the motor housing 70 and the inverter housing 90 are integrated. The common housing is provided with peripheral fins. In the common housing, the motor 61 and the inverter unit 170 correspond to heat generating parts.

[0179] In each of the above embodiments, the motor 61 does not have to be a double-rotor motor. For example, the motor 61 may be a single-rotor motor having one rotor. Furthermore, the motor 61 does not have to be an axial gap motor. For example, the motor 61 may be a radial gap motor. In this motor 61, the motor stator 62 and the motor rotor 63 are aligned in the radial direction RD.

[0180] In each of the above embodiments, the airflow of the propeller wind Wp may be generated in any manner. For example, a blower device such as a fan that generates an airflow flowing in the axial direction AD may be provided for the EPU 50. The blower device may or may not be included in the EPU 50. In addition, the airflow flowing in the axial direction AD may be a flight wind generated in conjunction with the flight of the eVTOL 10.

[0181] In each of the above embodiments, the eVTOL 10 may be configured such that at least one propeller 20 is driven by at least one EPU 50. For example, one propeller 20 may be driven by multiple EPUs 50, or multiple propellers 20 may be driven by one EPU 50.

[0182] In each of the above embodiments, the aircraft equipped with the EPU 50 does not have to be a vertical take-off and landing aircraft as long as it is an electric aircraft. For example, the aircraft may be an electric aircraft capable of take-off and landing with a runway. Furthermore, the aircraft may be a rotorcraft or a fixed-wing aircraft. The aircraft may be an unmanned aircraft with no people on board.

[0183] In each of the above embodiments, the moving body on which the EPU 50 is mounted does not have to be an aircraft as long as it can move by rotation of a rotating body. For example, the moving body may be a vehicle, a ship, a construction machine, or an agricultural machine. For example, if the moving body is a vehicle or a construction machine, the rotating body is a wheel for moving, and the output shaft is an axle. If the moving body is a ship, the rotating body is a screw propeller for propulsion, and the output shaft is a propeller shaft.

[0184] (Disclosure of technical ideas) This specification discloses multiple technical ideas described in the following multiple dependent claims. Some of the claims may be described in a multiple dependent form, where the subsequent claim alternatively refers to the preceding claim. Furthermore, some of the claims may be described in a multiple dependent form, where the subsequent claim alternatively refers to the preceding claim. The claims described in these multiple dependent forms define multiple technical ideas.

[0185] (Technical thought 1) A drive device (50) driven by electricity, A heat generating portion (170) that generates heat when current is applied; A housing (90) having an outer peripheral surface (910) extending in an axial direction (AD) and accommodating the heat generating portion; a plurality of outer peripheral fins (92) extending in the axial direction along the outer peripheral surface of the housing and arranged in a circumferential direction (CD) of the housing along the outer peripheral surface of the housing, for dissipating heat from the heat generating portion to the outside of the housing; Equipped with The housing outer circumferential surface has a first surface end portion (910a) and a second surface end portion (910b) as a pair of end portions aligned in the axial direction, The plurality of peripheral fins include a first outer peripheral fin (921, 921A) extending from a position aligned with the heat generating portion in a radial direction (RD) of the housing toward the first surface end of the first surface end and the second surface end; a second outer circumferential fin (922, 922A) provided at a position away from the first outer circumferential fin in a direction perpendicular to the radial direction and extending from a position aligned with the heat generating portion in the radial direction toward the second surface end of the first surface end and the second surface end; A drive unit having the above structure.

[0186] (Technical thought 2) The drive device according to Technical Idea 1, wherein the distance (D1) between two of the first outer peripheral fins adjacent to each other in the circumferential direction gradually becomes smaller in the axial direction toward the second surface end.

[0187] (Technical Thought 3) The drive device described in Technical Idea 1 or 2, wherein the first outer peripheral fin is an extension fin (921) whose circumferential width (W1) gradually expands toward the second surface end.

[0188] (Technical Thought 4) A first opposing opening (131b) that is open toward the second surface end side in the axial direction is formed between two of the first outer peripheral fins that are adjacent to each other in the circumferential direction, A second opposed opening (132a) that is open toward the first surface end side in the axial direction is formed between two of the second outer peripheral fins that are adjacent to each other in the circumferential direction, The drive device according to any one of Technical Concepts 1 to 3, wherein the first opposing opening and the second opposing opening are aligned in the axial direction.

[0189] (Technical Thought 5) The drive device described in technical idea 4 is provided with a fin interposition portion (202) extending in the radial direction, at least a portion of which is provided between the first opposing opening and the second opposing opening, and interposed at least between two of the first outer circumferential fins adjacent to each other in the circumferential direction and two of the second outer circumferential fins adjacent to each other in the circumferential direction.

[0190] (Technical Thought 6) a duct portion (201) that is provided on the outer peripheral side of the housing outer peripheral surface via the outer peripheral fin so as to cover the outer peripheral side of the housing outer peripheral surface, and that forms an outer peripheral flow path (130) through which a gas flows between the duct portion and the outer peripheral surface of the housing, The drive device described in Technical Idea 5, wherein the fin interposition portion extends in the radial direction from the duct portion toward the outer circumferential surface of the housing.

[0191] (Technical Thought 7) The drive device according to Technical Idea 5 or 6, further comprising, as the fin interposition portion, a tapered fin (202) whose circumferential width gradually decreases toward the outer circumferential surface of the housing.

[0192] (Technical Thought 8) The first outer circumferential fin and the second outer circumferential fin are spaced apart in the axial direction, The first outer peripheral fin has a first opposing end (113) which is an end on the second surface end side, The second outer peripheral fin has a second opposing end (122) which is an end on the first surface end side, The drive device according to any one of Technical Concepts 1 to 7, wherein the first opposed end and the second opposed end are shifted in the circumferential direction.

[0193] (Technical Thought 9) The first outer circumferential fin and the second outer circumferential fin are spaced apart in the axial direction, The first outer peripheral fin has a first opposing end (113) which is an end on the second surface end side, The second outer peripheral fin has a second opposing end (122) which is an end on the first surface end side, The first opposing end and the second opposing end are aligned in the axial direction, The drive device according to any one of Technical Concepts 1 to 8, wherein a width dimension (D2a) of the second opposing end in the circumferential direction is smaller than a width dimension (D1b) of the first opposing end.

[0194] (Technical Thought 10) The first outer circumferential fin and the second outer circumferential fin are spaced apart in the axial direction, A first opposing opening (131b) that is open toward the second surface end side in the axial direction is formed between two of the first outer peripheral fins that are adjacent to each other in the circumferential direction, The second outer peripheral fin has a second opposing end (122) which is an end on the first surface end side, The drive device according to any one of Technical Concepts 1 to 9, wherein the second opposing end is provided at a position aligned with the first opposing opening in the axial direction.

[0195] (Technical Thought 11) The heat generating portion is a plurality of surface-mounted components (175) arranged in the circumferential direction along the housing inner peripheral surface (913) of the housing and provided on the housing inner peripheral surface, The first outer peripheral fin extends from a position aligned with the surface mounting component in the radial direction toward the first surface end, The drive device according to any one of Technical Ideas 1 to 10, wherein the second outer peripheral fin extends from a position aligned with the surface-mounted component in the radial direction toward the second surface end.

[0196] (Technical Thought 12) a motor (61) to be supplied with power; an inverter unit (170) that converts the power supplied to the motor; Equipped with The axial direction is a direction in which a rotation axis (Cm) of the motor extends, 12. The drive device according to any one of Technical Concepts 1 to 11, wherein at least one of the motor and the inverter unit is accommodated in the housing as the heat generating unit.

[0197] (Technical Thought 13) The drive device according to any one of Technical Ideas 1 to 12, which is a rotating electric machine provided in an aircraft (10) and drives the aircraft to fly. [Explanation of symbols]

[0198] 10... eVTOL as an aircraft, 50... EPU as a drive unit, 61... motor, 90... inverter housing as a housing, 910... inverter outer peripheral surface as a housing outer peripheral surface, 910a... outer peripheral upstream end as a first surface end, 910b... outer peripheral downstream end as a second surface end, 913... inverter inner peripheral surface as a housing inner peripheral surface, 92... inverter fin as an outer peripheral fin, 921... first fin as a first outer peripheral fin and an extended fin, 921A... first parallel fin as a first outer peripheral fin, 922... second fin as a second outer peripheral fin, 922A... second parallel fin as a second outer peripheral fin Fin, 113...first downstream end as first opposing end, 122...second upstream end as second opposing end, 130...fin flow path as peripheral flow path, 131b...first downstream port as first opposing port, 132a...second upstream port as second opposing port, 170...inverter section as heat generating section, 175...switch component as surface mounted component, 201...duct main body as duct section, 202...duct fin as fin interposition section and tapered fin, D1...first spacing as spacing, D1b...downstream end spacing as width dimension, D2a...upstream end spacing as width dimension, W1...width dimension as width, AD...axial direction, CD...circumferential direction, RD...radial direction.

Claims

1. A driving device (50) driven by electricity, a heat generating portion (170) that generates heat when energized; a housing (90) having an outer circumferential surface (910) extending in an axial direction (AD) and accommodating the heat generating portion; a plurality of peripheral fins (92) extending in the axial direction along the outer peripheral surface of the housing, arranged in the circumferential direction (CD) of the housing along the outer peripheral surface of the housing, and dissipating heat from the heat generating portion to the outside of the housing; Equipped with The housing outer peripheral surface has a first surface end (910a) and a second surface end (910b) as a pair of end portions aligned in the axial direction, The plurality of outer circumferential fins include: a first outer peripheral fin (921, 921A) extending from a position aligned with the heat generating portion in the radial direction (RD) of the housing toward the first surface end of the first surface end and the second surface end; a second outer peripheral fin (922, 922A) provided at a position spaced apart from the first outer peripheral fin in a direction perpendicular to the radial direction, and extending from a position aligned with the heat generating portion in the radial direction toward the second surface end of the first surface end or the second surface end; Contains The first outer peripheral fin has a first opposing end (113) that is an end on the second surface end side, a distance (D1) between two adjacent first outer peripheral fins in the circumferential direction gradually decreases toward the second surface end in the axial direction; the first outer circumferential fin and the second outer circumferential fin are spaced apart in the axial direction, A drive device, wherein the distance (D3) between the first outer peripheral fin and the second outer peripheral fin in the axial direction is greater than the distance (D1b) between two adjacent first opposing ends in the circumferential direction.

2. The first peripheral fin has a first opposite end (112) which is an end on the second surface end side, The drive device according to claim 1 , wherein the distance is smaller than a distance (D1a) between two of the first opposite ends adjacent to each other in the circumferential direction.

3. The second outer peripheral fin has a second opposing end (122) which is an end on the first surface end side, The drive device according to claim 1 or 2, wherein the distance is greater than a distance (D2a) between two of the second opposing ends adjacent to each other in the circumferential direction.

4. The drive device according to claim 1 or 2, wherein the first outer peripheral fin is an expanding fin (921) whose circumferential width (W1) gradually expands toward the second surface end.

5. A first opposing opening (131b) that is open toward the second surface end side in the axial direction is formed between two of the first outer peripheral fins that are adjacent in the circumferential direction, A second opposing opening (132a) is formed between two of the second outer peripheral fins adjacent to each other in the circumferential direction, the second opposing opening (132a) being open toward the first surface end in the axial direction, The drive device according to claim 1 or 2, wherein the first opposing opening and the second opposing opening are aligned in the axial direction.

6. 6. The drive device of claim 5, further comprising a fin interposition portion (202) extending in the radial direction, at least a portion of which is provided between the first opposing opening and the second opposing opening, and interposed between at least one of two of the first outer peripheral fins adjacent to each other in the circumferential direction and two of the second outer peripheral fins adjacent to each other in the circumferential direction.

7. a duct portion (201) that is provided on the outer peripheral side of the housing outer peripheral surface via the outer peripheral fins so as to cover the outer peripheral surface of the housing from the outer peripheral side, and that forms an outer peripheral flow path (130) through which a gas flows between the duct portion and the outer peripheral surface of the housing, The drive unit according to claim 6 , wherein the fin interposition portion extends in the radial direction from the duct portion toward the outer circumferential surface of the housing.

8. The drive unit according to claim 6, wherein the fin interposition portion is provided with a tapered fin (202) whose width in the circumferential direction gradually decreases toward the outer peripheral surface of the housing.

9. The second outer peripheral fin has a second opposing end (122) which is an end on the first surface end side, The drive device according to claim 1 or 2, wherein the first opposing end and the second opposing end are offset from each other in the circumferential direction.

10. The second outer peripheral fin has a second opposing end (122) which is an end on the first surface end side, the first opposing end and the second opposing end are aligned in the axial direction, The drive device according to claim 1 or 2, wherein a width dimension (D2a) of the second opposing end in the circumferential direction is smaller than a width dimension (D1b) of the first opposing end.

11. A first opposing opening (131b) is formed between two of the first outer peripheral fins adjacent to each other in the circumferential direction, the opening being open toward the second surface end in the axial direction, The second outer peripheral fin has a second opposing end (122) that is an end on the first surface end side, The drive device according to claim 1 or 2, wherein the second opposing end is provided at a position aligned with the first opposing opening in the axial direction.

12. The heat generating portion is The housing has a plurality of surface-mounted components (175) arranged in the circumferential direction along the housing inner peripheral surface (913) of the housing and provided on the housing inner peripheral surface, the first outer peripheral fin extends from a position aligned with the surface-mounting component in the radial direction toward the first surface end, The drive unit according to claim 1 or 2, wherein the second outer peripheral fins extend from a position aligned with the surface-mounted component in the radial direction toward the second surface end.

13. a motor (61) to be supplied with power; an inverter unit (170) that converts the power supplied to the motor; Equipped with The axial direction is a direction in which a rotation axis (Cm) of the motor extends, The drive device according to claim 1 or 2, wherein at least one of the motor and the inverter unit is accommodated in the housing as the heat generating unit.

14. 3. The drive device according to claim 1, wherein the drive device is a rotating electric machine provided in an aircraft (10) and drives the aircraft to fly.

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