Drive device

Abstract

The inverter device (80) has an inverter case (90) and an inverter unit (170). The inverter unit (170) is housed in the inverter case (90). The inverter housing (90) is provided with a first fin (921) and a second fin (922). The first fins (921) and the second fins (922) are arranged along the inverter outer peripheral surface (910) in the axial direction (AD). The first fins (921) and the second fins (922) extend in the axial direction (AD) from positions aligned with the inverter unit (170) in the radial direction (RD). The first fins (921) extend upstream from the inverter unit (170). The second fins (922) extend downstream from the inverter unit (170).

Description

[0001] Cross Reference to Related Applications

[0002] This application is based on patent application No. 2023-142445 filed in Japan on September 1, 2023, and the content of the base application is incorporated herein by reference in its entirety. TECHNICAL FIELD

[0003] The disclosure in this specification relates to a drive device. BACKGROUND

[0004] In Patent Literature 1, a drive device provided with a heat dissipation fin is described. In this drive device, a plurality of heat dissipation fins are provided on the outer surface of a housing. The heat dissipation fins extend in a meandering manner along the outer surface of the housing. In Patent Literature 1, the meandering of the heat dissipation fins promotes the generation of turbulence in the air flowing between adjacent two heat dissipation fins, and thus the heat dissipation capacity of the heat dissipation fins is improved.

[0005] Prior Art Documents

[0006] Patent Literature

[0007] Patent Literature 1: Japanese Patent Application Publication No. 2008-186820 SUMMARY

[0008] However, it is conceivable in the above-described Patent Literature 1 that, since the heat dissipation fins are meandering as a whole, the pressure loss increases between adjacent two heat dissipation fins. When the pressure loss increases, the amount of air flowing between adjacent two heat dissipation fins decreases, and the heat dissipation effect of the heat dissipation fins can be reduced.

[0009] One of the objects of the present disclosure is to provide a drive device capable of improving the heat dissipation effect of a housing.

[0010] The plurality of modes disclosed in this specification achieve respective objects by mutually different technical means. In addition, the claims and the symbols in parentheses recited therein are one example, showing the correspondence with the specific means recited in the following embodiments described as a mode, and not limiting the technical scope.

[0011] To achieve the above object, the disclosed mode is a drive device, which is a drive device driven by electric power, including: a heat generating portion that generates heat in association with energization; a housing that has a housing outer peripheral surface extending in an axial direction, and accommodates the heat generating portion; and a peripheral fin that extends in the axial direction along the housing outer peripheral surface, is arranged in a plurality along the housing outer peripheral surface in a circumferential direction of the housing, and releases heat of the heat generating portion to the outside of the housing, The outer peripheral surface of the outer shell has a first end face and a second end face, which are a pair of ends arranged along the axial direction. Multiple peripheral fins have: The first outer peripheral fin extends from a position radially aligned with the heating element along the outer shell towards the first end of the first surface and the second end of the second surface; and The second outer peripheral fin is disposed at a position separated from the first outer peripheral fin in a direction orthogonal to the radial direction, and extends from a position arranged radially with the heating element to the second end of the first and second surfaces.

[0012] According to the above method, the first and second outer peripheral fins are positioned separately in a direction orthogonal to the axial direction. In this structure, at the position radially aligned with the heating element, the air or other gas flowing in the space between the first and second outer peripheral fins is prone to turbulence, such as eddies. Therefore, the heat dissipation effect of the heating element released through the first outer peripheral fin, the second outer peripheral fin, and the outer peripheral surface of the outer shell can be improved by the gas turbulence. Thus, by locally generating gas turbulence on the outer side of the outer shell at the position radially aligned with the heating element, the increase in pressure loss in the entire space between the two circumferentially adjacent outer peripheral fins can be suppressed. Therefore, the insufficient amount of gas flowing between the two circumferentially adjacent outer peripheral fins can be suppressed, and the heat dissipation effect of the heating element achieved by the gas can be improved. As described above, the heat dissipation effect of the outer shell can be improved in the drive device by means of the outer peripheral fins. Attached Figure Description

[0013] Figure 1 This is a diagram showing the structure of the eVTOL in the first embodiment.

[0014] Figure 2 This is a diagram showing the electrical structure of the propulsion system.

[0015] Figure 3 This is a side view of the propulsion device.

[0016] Figure 4 This is a top view of the inverter unit.

[0017] Figure 5 yes Figure 3 VV-line sectional view.

[0018] Figure 6 yes Figure 4 The VI-VI line sectional view is a longitudinal sectional view of the inverter device.

[0019] Figure 7 This is an enlarged side view of the switching components in the inverter unit.

[0020] Figure 8 It is a diagram used to illustrate the temperature boundary layer.

[0021] Figure 9 This is an enlarged side view of the perimeter of the motor in the inverter unit.

[0022] Figure 10 This is an enlarged side view of the switching components in the inverter device of Comparative Example 2.

[0023] Figure 11 This is an enlarged side view of the area surrounding the switching components in the inverter device of Comparative Example 2.

[0024] Figure 12 This is an enlarged side view of the periphery of the motor diameter in the inverter device of the second embodiment.

[0025] Figure 13 This is an enlarged side view of the periphery of the motor diameter in the inverter device of the third embodiment.

[0026] Figure 14 This is a top view of the inverter device according to the fourth embodiment.

[0027] Figure 15 yes Figure 16 XV-XV line sectional view.

[0028] Figure 16 yes Figure 14 XVI-XVI line sectional view.

[0029] Figure 17 yes Figure 16 Sectional view along line XVII-XVII. Detailed Implementation

[0030] Hereinafter, various embodiments for implementing this disclosure will be described with reference to the accompanying drawings. In each embodiment, the same reference numerals are sometimes used to denote parts corresponding to those described in previous embodiments, and repeated descriptions are omitted. Where only a portion of the structure is described in each embodiment, other previously described embodiments can be applied to the remaining parts of the structure. Not only are combinations of combinable parts specifically and explicitly described in each embodiment, but even without explicit description, embodiments can be partially combined as long as they do not hinder combination.

[0031] <First Implementation>

[0032] Figure 1The eVTOL 10 shown is an electric vertical take-off and landing (eVTOL) aircraft. An eVTOL aircraft is an electrically powered vertical take-off and landing (VTOL) aircraft capable of vertical take-off and landing. eVTOL is short for electric vertical take-off and landing aircraft. The eVTOL 10 is an electrically powered aircraft that flies in the atmosphere, sometimes referred to as an electric aircraft. The eVTOL 10 is also an electrically powered aircraft, sometimes referred to as an electric aircraft. The eVTOL 10 is a manned aircraft with a crew. The crew of the eVTOL 10 includes the pilot, who acts as the operator and pilot.

[0033] The eVTOL 10 has a fuselage 11 and a propeller 20. The fuselage 11 has a main fuselage body 12 and wings 13. The main fuselage body 12 is the body of the fuselage 11, for example, in a shape that extends forward and backward. The main fuselage body 12 has a crew cabin 14 for occupants. Wings 13 extend from the main fuselage body 12, and multiple wings are provided on the main fuselage body 12. Wings 13 are fixed wings. The multiple wings 13 include main wings, tail fins, etc.

[0034] The eVTOL 10 has a cabin. The cabin is located inside the eVTOL 10. For example, the cabin is the interior space of the main fuselage 12, formed by the main fuselage 12. As a cabin, there are crew compartments 14 and cargo compartments, etc. As a crew compartment 14, there are passenger cabins and pilot cabins, etc. Seating is provided in the crew compartment 14 for crew members. The crew compartment 14 can be used without crew members or to store cargo.

[0035] Multiple propellers 20 are provided on the fuselage 11. The eVTOL 10 is a multi-copter aircraft with at least three propellers 20. For example, at least six propellers 20 are provided on the fuselage 11. The propellers 20 are respectively located on the main fuselage 12 and the wing 13. The propellers 20 rotate around a propeller axis. The propeller axis is, for example, the centerline of the propeller 20. The propellers 20 enable the eVTOL 10 to generate thrust and lift. The propellers 20 are sometimes referred to as rotors or rotary wings.

[0036] In eVTOL 10, the presence of multiple propellers 20 facilitates airframe balance. Even if the output of one propeller 20 unexpectedly decreases, flight can continue thanks to the remaining propellers 20. Propeller output includes the rotational speed and torque of the propeller 20.

[0037] The propeller 20 has blades, a hub, and a propeller shaft. Multiple blades are arranged circumferentially along the propeller axis. The hub connects the multiple blades. The propeller shaft is the axis of rotation of the propeller 20, extending from the hub along the propeller axis.

[0038] The eVTOL 10 has several flight modes, including vertical takeoff, vertical landing, cruise, and hovering. Flight modes are sometimes referred to as flight configurations. During vertical takeoff, the eVTOL 10 can take off without taxiing. During vertical takeoff, the eVTOL 10 can ascend vertically or diagonally upwards. During vertical landing, the eVTOL 10 can land without taxiing. During vertical landing, the eVTOL 10 can descend vertically or diagonally downwards.

[0039] Cruise is sometimes referred to as level flight. During cruise, the eVTOL 10 can fly horizontally without moving vertically, or it can move vertically while flying horizontally. Hovering is sometimes referred to as stationary flight. During hovering, the eVTOL 10 can fly at a designated position in the air, or it can deviate from the designated position vertically and horizontally.

[0040] Additionally, the eVTOL 10's flight modes include lift. In lift mode, the eVTOL 10 moves vertically. As lift, the eVTOL 10 can ascend diagonally upwards or descend diagonally downwards. The eVTOL 10 takes off vertically by generating lift upwards. The eVTOL 10 lands vertically by generating lift downwards.

[0041] The eVTOL 10 is a tiltrotor aircraft. In the eVTOL 10, the tilt angle of the propeller 20 is adjustable. In the eVTOL 10, a single propeller 20 can function as both a lift propeller and a cruise propeller. For example, when the eVTOL 10 is generating lift, the tilt angle is adjusted so that the propeller 20 functions as a lift rotor. When the eVTOL 10 is cruising, the tilt angle is adjusted so that the propeller 20 functions as a cruise rotor. Alternatively, the eVTOL 10 may not be a tiltrotor aircraft. For example, the eVTOL 10 may have a separate lift propeller 20 and a separate cruise propeller 20.

[0042] Figure 2 The propulsion system 30 shown is installed on the eVTOL 10. The propulsion system 30 is a system that drives the eVTOL 10 to propel itself. The propulsion system 30 includes a battery 31 and an EPU 50. The battery 31 and EPU 50 are installed in the EPU 50. Additionally, the propulsion system 30 has a flight control device (not shown). The flight control device performs flight control for enabling the eVTOL 10 to fly. In flight control, the propulsion system 30 and the EPU 50 are controlled.

[0043] Battery 31 is connected to EPU 50 in a power-conducting manner. Battery 31 is a power supply unit that supplies power to EPU 50, equivalent to a power source. Battery 31 is a DC voltage source that applies DC voltage to EPU 50. Battery 31 has a rechargeable secondary battery. Such a secondary battery may be a lithium-ion battery, a nickel-metal hydride battery, etc. Battery 31 can store electricity, equivalent to an energy storage device. Alternatively, fuel cells, generators, etc., may be used as a power source in addition to or as a replacement for battery 31.

[0044] exist Figure 1 , Figure 2 In this configuration, EPU 50 is an electrically driven device, essentially a drive unit. EPU 50 is used to drive the propeller 20 to rotate. EPU stands for Electric Propulsion Unit. EPU 50 is sometimes referred to as an electric drive unit or electric drive system. EPU 50 is provided for each of the multiple propellers 20. EPU 50 and propellers 20 are arranged along the propeller axis. Multiple EPUs 50 are fixed to the fuselage 11. EPU 50 supports the propellers 20 for rotation. EPU 50 is connected to the propellers 20. Propellers 20 are fixed to the fuselage 11 via EPU 50.

[0045] like Figure 1 As shown, the eVTOL 10 has a propulsion device 100. The propulsion device 100 is configured to include a propeller 20 and an EPU 50. The propulsion device 100 is a device for propulsing the eVTOL 10. The propulsion device 100 rotates the propeller 20 to make the eVTOL 10 fly. The eVTOL 10 is also a moving body that moves via the propulsion device 100. Multiple propulsion devices 100 are provided on the eVTOL 10. One propulsion device 100 includes a propeller 20 and an EPU 50 for driving the propeller 20. Alternatively, only the propeller 20 and the EPU 50 may be referred to as the propulsion device 100.

[0046] The EPU 50 has a motor unit 60 and an inverter unit 80. The motor unit 60 has a motor 61 and a motor housing 70. The motor housing 70 is a casing that houses the motor 61. The motor 61 is a multiphase AC motor. The motor 61 is a multiphase AC rotating motor. The motor 61 is the flight drive source for the eVTOL 10, functioning as a motor. The motor 61 is also an electric generator. The motor 61 functions as a generator during regeneration. For example, a brushless motor may be used as the motor 61.

[0047] Electric motor 61 drives propeller 20 to rotate, enabling eVTOL 10 to fly. Electric motor 61 is a flight electric motor used to enable eVTOL 10 to fly. Electric motor 61 drives propeller 20 to rotate by operating on battery power. Battery power is supplied to electric motor 61 from battery 31.

[0048] like Figure 3 As shown, the electric motor 61 has a stator 62, a rotor 63, and a shaft 64. The stator 62 is a fixed component, fixed to the motor housing 70. The rotor 63 rotates relative to the stator 62. The rotation of the rotor 63 is sometimes referred to as the rotation of the electric motor 61. The shaft 64 rotates together with the rotor 63. The shaft 64 is supported by the motor housing 70, etc., to enable rotation. The shaft 64 is connected to the propeller 20. In the propulsion device 100, the propeller 20 rotates together with the shaft 64.

[0049] Motor 61 is, for example, an axially spaced type motor. In motor 61, the motor stator 62 and the motor rotor 63 are arranged along the motor axis Cm in the axial direction AD. Motor 61 is a dual-rotor type motor. In motor 61, two motor rotors 63 are arranged along the axial direction AD, separated by the motor stator 62.

[0050] The motor axis Cm is the centerline of the motor 61, and is an imaginary line extending in a straight line. The motor rotor 63 rotates around the motor axis Cm. The motor axis Cm is equivalent to the axis of rotation. 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 mutually orthogonal. The circumferential direction CD is the direction of rotation of the motor 61. With respect to the radial direction RD, the outer side is sometimes referred to as the radial outer side or outer circumferential side, and the inner side is sometimes referred to as the radial inner side or inner circumferential side.

[0051] Inverter unit 80 supplies power to motor unit 60 to drive motor unit 60. Inverter unit 80 is a drive unit for driving motor 61, equivalent to a motor drive unit. Inverter unit 80 has inverter section 170 and inverter housing 90. Inverter housing 90 is a casing that houses inverter section 170. Inverter section 170 is capable of converting electricity. In inverter section 170, the power supplied from battery 31 to motor 61 is converted. Inverter section 170 is generally formed in a plate shape. Inverter section 170 extends in a direction orthogonal to axis AD.

[0052] The motor assembly 60 and the inverter assembly 80 are arranged along the axial direction AD. For example, the inverter assembly 80 is disposed between the motor assembly 60 and the propeller 20 along the axial direction AD. The motor shaft 64 is connected to the propeller 20 with the inverter assembly 80 passing through it along the axial direction AD.

[0053] like Figure 2 As shown, the inverter device 80 includes an inverter circuit 81, a smoothing capacitor 145, a filter circuit 150, and a control circuit 160. Figure 3 In the diagram, motor 61 is represented as MG, filter circuit 150 is represented as EMI, and control circuit 160 is represented as CD.

[0054] 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 connect the battery 31 and the inverter circuit 81 to enable power supply. The P-line 141 and the N-line 142 are formed by busbars, electrical 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.

[0055] P-line 141 is electrically connected to the positive terminal of battery 31. N-line 142 is electrically connected to the negative terminal of battery 31. In battery 31, the positive terminal is the electrode on the high-potential side, and the negative terminal is the electrode on the low-potential side. P-line 141 and N-line 142 are power lines used to supply power from battery 31 to inverter circuit 81. P-line 141 is the high-potential side power line and is sometimes referred to as the high-potential line. N-line 142 is the low-potential side power line and is sometimes referred to as the low-potential line.

[0056] Output line 143 is a power line used to supply power from inverter circuit 81 to motor 61. Output line 143 connects motor 61 and inverter circuit 81 to enable power supply. For example, output line 143 is energizedly connected to motor stator 62. Output line 143 is formed by busbars, electrical wiring, etc. At least a portion of output line 143 is included in inverter device 80.

[0057] The smoothing capacitor 145 is a capacitor used to smooth the DC voltage supplied from the battery 31. The smoothing capacitor 145 is connected between the battery 31 and the inverter circuit 81 via P-line 141 and N-line 142. The smoothing capacitor 145 is connected in parallel with the inverter circuit 81.

[0058] The filter circuit 150 is used to reduce noise such as electromagnetic noise. EMI filters are a type of filter circuit 150. The filter circuit 150 is positioned between the smoothing capacitor 145 and the battery 31. The filter circuit 150 is connected in parallel with the inverter circuit 81 relative to the battery 31. The filter circuit 150 includes a choke coil and a filter capacitor. Common-mode coils and normal-mode coils are examples of choke coils. Y-capacitors and X-capacitors are examples of filter capacitors.

[0059] Inverter circuit 81 is a circuit used for power conversion. Inverter circuit 81 performs power conversion on multiple phases separately. Inverter circuit 81 converts DC power from battery 31 into AC power, and supplies the AC power to motor 61. For example, inverter circuit 81 is a DC-AC conversion circuit.

[0060] The inverter circuit 81 has multiple corresponding upper and lower arm circuits 83. For example, the inverter circuit 81 has upper and lower arm circuits 83 for the U phase, V phase, and W phase respectively. The upper and lower arm circuits 83 have an upper arm 84 and a lower arm 85. The upper arm 84 and the lower arm 85 are connected in series with 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 circuits 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.

[0061] The upper arm 84 and lower arm 85 have an arm switch 86 and an arm diode 87. The arm switch 86 is formed from a semiconductor switch, etc. A semiconductor switch is a switch without mechanical contacts. The arm switch 86 is, for example, a MOSFET, IGBT, or other transistor. MOSFET is short for Metal-Oxide-Semiconductor Field-Effect Transistor. IGBT is short for Insulated-Gate Bipolar Transistor. The arm switch 86 is a switching element that can convert electrical power through switching. The switching element is a semiconductor element such as a power element. The arm switch 86 is a changeover switch used for converting electrical power.

[0062] Arm diode 87 is a diode used for return current. Arm diode 87 is connected in reverse parallel with arm switch 86. Arm diode 87 can also be a parasitic diode of arm switch 86, or it can be a diode that is separate from the parasitic diode.

[0063] Control circuit 160 performs motor control of motor 61. Motor control includes control of inverter circuit 81, etc. Control circuit 160 is a control device such as ECU. Control circuit 160 is sometimes referred to as inverter control unit or motor control unit. Control circuit 160 is communicatively connected to inverter circuit 81. Control circuit 160 controls motor via inverter circuit 81 by outputting command signals.

[0064] Additionally, the inverter device 80 includes a drive circuit. This drive circuit is used to drive the inverter circuit 81. The control circuit 160 is communicatively connected to the inverter circuit 81 via the drive circuit. The drive circuit is energizedly connected to the arm switch 86. The drive circuit generates a drive voltage based on a command signal from the control circuit 160. The drive circuit drives the arm switch 86 by applying the drive voltage to it.

[0065] exist Figure 3 In the propulsion device 100, propeller wind Wp is generated as the propeller 20 rotates. Propeller wind Wp flows along the axial direction AD. Propeller wind Wp is an airflow generated by the flow of gases such as air. The gas that generates the airflow such as propeller wind Wp is sometimes referred to as a refrigerant. In this embodiment, propeller wind Wp flows from the propeller 20 to the EPU 50. In the EPU 50, propeller wind Wp flows from the inverter device 80 to the motor device 60. The inverter device 80 is located upstream of the motor device 60 relative to the propeller wind Wp.

[0066] The motor housing 70 has a main body 71 and fins 72. Both the main body 71 and the fins 72 are made of a metallic material and are thermally conductive. The main body 71 forms the inner and outer surfaces of the motor housing 70. The outer surface of the main body 71 includes an outer peripheral surface 710, an upstream surface 711, and a downstream surface 712. The outer peripheral surface 710 is annular and extends along the axial direction AD. The motor 61 is housed within the inner periphery of the outer peripheral surface 710.

[0067] The upstream face 711 and the downstream face 712 of the electric motor are arranged along the axial direction AD, separated by the outer peripheral surface 710 of the motor. The upstream face 711 and the downstream face 712 extend in a direction orthogonal to the axial direction AD. The upstream face 711 and the downstream face 712 cover the electric motor 61 from the axial direction AD. For the propeller wind Wp, the upstream face 711 is located closer to the upstream side than the downstream face 712.

[0068] Motor fins 72 are disposed on the outer surface of the motor housing 70. Motor fins 72 are heat dissipation fins for dissipating heat from the motor assembly 60 to the outside. Motor fins 72 are formed in a plate shape and extend in a direction orthogonal to the circumferential direction CD. Motor fins 72 are disposed on the outer peripheral surface 710 of the motor. Motor fins 72 extend from the outer peripheral surface 710 of the motor towards the outer periphery. Motor fins 72 extend along the outer peripheral surface 710 of the motor in the axial direction AD. Multiple motor fins 72 are arranged along the outer peripheral surface 710 of the motor in the circumferential direction CD. Additionally, multiple motor fins 72 are arranged along the outer peripheral surface 710 of the motor in the axial direction AD.

[0069] like Figure 3 , Figure 6 As shown, the inverter housing 90 has an inverter housing body 91 and inverter fins 92. The inverter housing body 91 and inverter fins 92 are formed of a metallic material and have thermal conductivity. The inverter housing body 91 forms the inner and outer surfaces of the inverter housing 90. The outer surface of the inverter housing 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 along the axial direction AD. The inverter housing 90 corresponds to the housing. The inverter outer peripheral surface 910 corresponds to the outer peripheral surface of the housing. The inverter inner peripheral surface 913 corresponds to the inner peripheral surface of the housing. Furthermore, in... Figure 6 The illustration of the motor housing 70, etc., is omitted in the text.

[0070] The inverter outer peripheral surface 910 has an upstream peripheral end 910a and a downstream peripheral end 910b as a pair of ends arranged along the axial direction AD. The upstream peripheral end 910a is the end on the inverter upstream surface 911 side of the pair of ends of the inverter outer peripheral surface 910. The upstream peripheral end 910a extends along the outer peripheral end of the inverter upstream surface 911 in the circumferential direction CD. The upstream peripheral end 910a corresponds to the first surface end. The downstream peripheral end 910b is the end on the inverter downstream surface 912 side of the pair of ends of the inverter outer peripheral surface 910. The downstream peripheral end 910b extends along the outer peripheral end of the inverter downstream surface 912 in the circumferential direction CD. The downstream peripheral end 910b corresponds to the second surface end.

[0071] The upstream surface 911 and the downstream surface 912 of the inverter are arranged along the axial direction AD, separated by the outer peripheral surface 910 of the inverter. The upstream surface 911 and the downstream surface 912 extend in a direction orthogonal to the axial direction AD. The upstream surface 911 and the downstream surface 912 cover the inverter section 170 from the axial direction AD. The upstream surface 911 corresponds to the casing covering surface. For a propeller wind Wp, the upstream surface 911 is located closer to the upstream side than the downstream surface 912.

[0072] In EPU 50, the upstream face 711 of the motor and the downstream face 912 of the inverter overlap. In EPU 50, the outer peripheral face 710 of the motor and the outer peripheral face 910 of the inverter are arranged along the axial direction AD. For the propeller wind Wp, the upstream face 911 of the inverter is located closer to the upstream side than the downstream face 712 of the motor.

[0073] The inverter housing 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 along the axial direction AD. The inverter section 170 is housed within the inner peripheral side of the inverter outer peripheral wall 95.

[0074] The upstream wall 96 of the inverter forms the upstream surface 911 of the inverter. The upstream surface 911 of the inverter is the outer surface of the upstream wall 96 of the inverter. The downstream wall 97 of the inverter forms the downstream surface 912 of the inverter. The downstream surface 912 of the inverter is the outer surface of the downstream wall 97 of the inverter. The upstream wall 96 and the downstream wall 97 of the inverter are arranged along the axial direction AD, separated by the outer peripheral wall 95 of the inverter. The upstream wall 96 and the downstream wall 97 of the inverter extend in a direction orthogonal to the axial direction AD. The upstream wall 96 and the downstream wall 97 of the inverter cover the inverter section 170 from the axial direction AD. The upstream wall 96 and the downstream wall 97 of the inverter enclose the inner space of the outer peripheral wall 95 of the inverter from the axial direction AD. For a propeller wind Wp, the upstream wall 96 of the inverter is located closer to the upstream side than the downstream wall 97 of the inverter.

[0075] exist Figure 5 , Figure 6 In this inverter section 170, an inverter circuit 81, a smoothing capacitor 145, a filter circuit 150, a control circuit 160, etc., are formed. The inverter section 170 includes an inverter substrate 171, a switching component 175, a capacitor component 176, and a filter component 177. The inverter substrate 171 is a circuit substrate. The inverter substrate 171 extends along the upstream wall 96 and the downstream wall 97 of the inverter in a direction orthogonal to the axial direction AD. The inverter substrate 171 is disposed between the upstream wall 96 and the downstream wall 97 of the inverter. In the axial direction AD, the distance between the inverter substrate 171 and the outer peripheral upstream wall 96a is greater than the distance between the inverter substrate 171 and the inner peripheral upstream wall 96b.

[0076] Switching component 175, capacitor component 176, and filter component 177 are electrical or electronic components. Components 175 to 177 are mounted on the inverter substrate 171 as mounting components. Components 175 to 177 protrude from the inverter substrate 171 toward the upstream wall 96 of the inverter. At least a portion of each of components 175 to 177 is disposed between the inverter substrate 171 and the upstream wall 96 of the inverter. Furthermore, in Figure 6 The illustrations of capacitor component 176, filter component 177, etc. are omitted in the text.

[0077] Switching component 175 forms the arm switch 86. Capacitor component 176 forms the smoothing capacitor 145. Filter component 177 forms the filter circuit 150. Filter component 177 may include components forming a choke coil or components forming a filter capacitor. Alternatively, capacitor component 176 may also be a component forming a filter capacitor.

[0078] Multiple switching components 175 are arranged circumferentially along the inner peripheral surface 913 of the inverter on the CD direction. The switching components 175 are disposed on the inner peripheral surface 913 of the inverter. The switching components 175 are equivalent to surface-mount components. The switching components 175 are fixed to at least one of the inverter substrate 171 and the inner peripheral surface 913 of the inverter. The switching components 175 are disposed on the inner peripheral surface 913 of the inverter in a state where heat transfer occurs from the switching components 175 to the outer peripheral wall 95 of the inverter. For example, the switching components 175 are fixed to the outer peripheral wall 95 of the inverter by screws or other fasteners while in contact with the inner peripheral surface 913 of the inverter. Alternatively, the switching components 175 may also be disposed on the inner peripheral surface 913 of the inverter via heat transfer gel or fixing members.

[0079] A switching component 175 is disposed along the axial direction AD between the upstream end 910a and the downstream end 910b of the inverter. The switching component 175 is positioned away from both the upstream wall 96 and the downstream wall 97 of the inverter. The switching component 175 is positioned where the outer peripheral centerline Crd passes through. For example, the outer peripheral centerline Crd passes through the center of the switching component 175. The outer peripheral centerline Crd is a centerline passing through the center of the outer peripheral surface 910 of the inverter along the axial direction AD. The outer peripheral centerline Crd passes precisely between the upstream end 910a and the downstream end 910b. The outer peripheral centerline Crd is an imaginary line extending in a straight line. The outer peripheral centerline Crd is orthogonal to the motor axis Cm.

[0080] The capacitor component 176 and the filter component 177 are positioned closer to the inner periphery than the switch component 175. For example, the capacitor component 176 and the filter component 177 are positioned away from the switch component 175 towards the inner periphery. The capacitor component 176 and the filter component 177 correspond to the inner periphery components. The capacitor component 176 and the filter component 177 are positioned away from the motor shaft 64 towards the outer periphery.

[0081] In EPU 50, the motor unit 60 and inverter unit 80 generate heat as the motor 61 is driven. In the motor unit 60, the motor 61 generates heat as power is supplied to it. In the inverter unit 80, the inverter section 170 generates heat as power is supplied to it. For example, in inverter unit 80, the switching arm switch 86, smoothing capacitor 145, and filter circuit 150 generate heat as power is supplied to them, including the switching component 175, capacitor component 176, and filter component 177. The inverter section 170 is equivalent to a heat-generating component. The switching component 175, capacitor component 176, and filter component 177 are equivalent to heat-generating parts.

[0082] The control circuit 160 and the drive circuit can be formed from the inverter substrate 171, or they can be formed from other circuit substrates different from the inverter substrate 171. For example, other circuit substrates are arranged along the axial direction AD with the inverter substrate 171 and are housed together with the inverter substrate 171 in the inverter housing 90.

[0083] like Figure 3 , Figure 6 As shown, inverter fins 92 are disposed on the outer surface of the inverter housing 90. Inverter fins 92 are heat dissipation fins used to dissipate heat from the inverter device 80 to the outside. Inverter fins 92 are formed in a plate shape and extend in a direction orthogonal to the circumferential direction CD. Inverter fins 92 are disposed on the outer peripheral surface 910 of the inverter. Inverter fins 92 extend from the outer peripheral surface 910 of the inverter towards the outer periphery. Inverter fins 92 extend along the outer peripheral surface 910 of the inverter in the axial direction AD. Multiple inverter fins 92 are arranged along the outer peripheral surface 910 of the inverter in the circumferential direction CD (see reference). Figure 4 , Figure 5 Additionally, multiple inverter fins 92 are arranged along the outer peripheral surface 910 of the inverter in the axial direction AD. The inverter fins 92 are equivalent to the outer peripheral fins.

[0084] Multiple inverter fins 92 include first fins 921 and second fins 922. The first fins 921 and second fins 922 are contained within an inverter housing 90. The first fins 921 and second fins 922 are arranged along the outer peripheral surface 910 of the inverter in the axial direction AD. The first fins 921 and second fins 922 are located at a position separated in a direction orthogonal to the radial direction RD. For example, the first fins 921 and second fins 922 are located at a position separated in the axial direction AD. Multiple first fins 921 and second fins 922 are arranged along the outer peripheral surface 910 of the inverter in the circumferential direction CD.

[0085] The first fin 921 is positioned closer to the upstream end 910a of the outer periphery than the second fin 922. The first fin 921 is positioned axially AD between the second fin 922 and the upstream end 910a of the outer periphery. The first fin 921 is positioned closer to the upstream end 910a of the outer periphery than the outer periphery centerline Crd. The first fin 921 is sometimes referred to as the upstream fin.

[0086] The second fin 922 is disposed along the axial direction AD between the first fin 921 and the downstream end 910b of the outer periphery. The second fin 922 is positioned closer to the downstream end 910b of the outer periphery than the outer periphery centerline Crd. For a propeller wind Wp, the first fin 921 is located closer to the upstream side than the second fin 922. The second fin 922 is sometimes referred to as the downstream fin.

[0087] like Figure 7 As shown, the first fin 921 has a pair of first fin surfaces 111. The first fin surface 111 is the plate surface of the first fin 921. The first fin surface 111 extends in a direction orthogonal to the circumferential direction CD. The pair of first fin surfaces 111 are arranged along the circumferential direction CD. The first fin surface 111 is also the side surface of the first fin 921, and is sometimes referred to as the fin side surface.

[0088] The first fin 921 has a first upstream end 112 and a first downstream end 113 as a pair of ends arranged along 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 on the outer peripheral upstream end 910a side of the pair of ends of the first fin 921. The first upstream end 112 has an end face extending in a direction orthogonal to the axial direction AD. The end face of the first upstream end 112 faces the outer peripheral 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 on the outer peripheral downstream end 910b side of the pair of ends of the first fin 921. The first downstream end 113 has an end face extending in a direction orthogonal to the axial direction AD. The end face of the first downstream end 113 faces the outer peripheral downstream end 910b side.

[0089] The first fin 921 has a circumferentially expanding shape (CD) that gradually expands from the first upstream end 112 to the first downstream end 113. The first fin 921 is equivalent to an expanding fin. The first fin 921 continuously expands towards the first downstream end 113. The width dimension W1 of the first fin 921 gradually increases towards the first downstream end 113. The width dimension W1 is equivalent 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 with the smallest width dimension W1 is the first upstream end 112. In the first fin 921, the portion with the largest width dimension W1 is the first downstream end 113. The width dimension W1b of the first downstream end 113 is greater than the width dimension W1a of the first upstream end 112.

[0090] In the first fin 921, one of a 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 circumferentially to the CD relative to the motor axis Cm. For example, one of the pair of first fin surfaces 111 is inclined to one side of the circumferential direction CD relative to the motor axis Cm. The other of the pair of first fin surfaces 111 is inclined to the other side of the circumferential direction CD relative to the motor axis Cm. The first fin 921 is formed in a conical shape. The first fin surface 111 extends straight along the axial direction AD. The first fin surface 111 is a conical surface.

[0091] Additionally, the first fin 921 may expand in stages toward the first downstream end 113. For example, the first fin surface 111 may also be a stepped surface. Furthermore, the first fin surface 111 may be curved in a manner that is concave or bulging in the circumferential direction CD. For example, the first fin surface 111 may also be a curved surface or a folded surface.

[0092] At least a portion of the first fin 921 is disposed in a position arranged radially RD with the inverter section 170. In the first fin 921, a first downstream end 113 is disposed in a position arranged radially RD with the inverter section 170. The first fin 921 extends from the inverter section 170 only towards the outer peripheral upstream end 910a and the outer peripheral downstream end 910b. The first fin 921 corresponds to a first outer peripheral fin.

[0093] For example, at least a portion of the first fin 921 is disposed at a position aligned radially with the switching component 175 along the RD direction. In the first fin 921, a first downstream end 113 is disposed at a position aligned radially with the switching component 175 along the RD direction. The first fin 921 extends only from its outer peripheral upstream end 910a and outer peripheral downstream end 910b.

[0094] For two adjacent first fins 921 on the circumferential CD, the first gap D1 gradually decreases from the first upstream end 112 toward the first downstream end 113. The first gap D1 is the distance between two adjacent first fins 921 on the circumferential CD. The first gap D1 continuously decreases from the first upstream end 112 toward the first downstream end 113. As the first gap D1, there are upstream end gap D1a and downstream end gap D1b. The upstream end gap D1a is the distance between two adjacent first upstream ends 112 on the circumferential CD. The downstream end gap D1b is the distance between adjacent first downstream ends 113 on the circumferential CD. The downstream end gap D1b is smaller than the upstream end gap D1a. For the first fin 921, the width dimension W1 gradually increases from the first upstream end 112 toward the first downstream end 113, thereby the first gap D1 gradually decreases from the first upstream end 112 toward the first downstream end 113.

[0095] The second fin 922 has a pair of second fin surfaces 121. The second fin surfaces 121 are the plate surfaces of the second fin 922. The second fin surfaces 121 extend in a direction orthogonal to the circumferential direction CD. The pair of second fin surfaces 121 are arranged along the circumferential direction CD. The second fin surfaces 121 are also the sides of the second fin 922, and are sometimes referred to as fin sides.

[0096] The second fin 922 has a second upstream end 122 and a second downstream end 123 as a pair of ends arranged along 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 on the outer peripheral upstream end 910a side of the pair of ends of the second fin 922. The second upstream end 122 has an end face extending in a direction orthogonal to the axial direction AD. The end face of the second upstream end 122 faces the outer peripheral 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 on the outer peripheral downstream end 910b side of the pair of ends of the second fin 922. The second downstream end 123 has an end face extending in a direction orthogonal to the axial direction AD. The end face of the second downstream end 123 faces the outer peripheral downstream end 910b side.

[0097] The second fin 922 has a shape that gradually tapers along the circumferential direction CD from the second upstream end 122 towards the second downstream end 123. The second fin 922 is sometimes referred to as a tapering fin. The second fin 922 continuously tapers towards the second downstream end 123. The width dimension W2 of the second fin 922 gradually decreases towards the second downstream end 123. The width dimension W2 is the width of the second fin 922 along the circumferential direction CD. The portion of the second fin 922 with the largest width dimension W2 is the second upstream end 122. The portion of the second fin 922 with the smallest width dimension W2 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.

[0098] 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 circumferentially to the CD relative to the motor axis Cm. For example, one of the pair of second fin surfaces 121 is inclined to the CD relative to the motor axis Cm. The other of the pair of second fin surfaces 121 is inclined to the CD relative to the motor axis Cm. The second fin 922 is formed in a conical shape. The second fin surface 121 extends straight along the axial direction AD. The second fin surface 121 is a conical surface.

[0099] Additionally, the second fin 922 may expand in stages toward the second downstream end 123. For example, the second fin surface 121 may also be a stepped surface. Furthermore, the second fin surface 121 may be curved in a manner that is concave or bulging in the circumferential direction CD. For example, the second fin surface 121 may also be a curved surface or a folded surface.

[0100] At least a portion of the second fin 922 is disposed at a position aligned radially RD with the switching component 175. In the second fin 922, a second upstream end 122 is disposed at a position aligned radially RD with the switching component 175. The second fin 922 extends from the first upstream end 112 only to the outer peripheral downstream end 910b of the outer peripheral upstream end 910a and outer peripheral downstream end 910b. The second fin 922 corresponds to a second outer peripheral fin.

[0101] For two adjacent second fins 922 on the circumferential CD, the second gap D2 gradually increases from the second upstream end 122 towards the second downstream end 123. The second gap D2 is the distance between two adjacent second fins 922 on the circumferential CD. The second gap D2 continuously decreases from the second upstream end 122 towards the second downstream end 123. The second gap D2 includes an upstream gap D2a and a downstream gap D2b. The upstream gap D2a is the distance between two adjacent second upstream ends 122 on the circumferential CD. The downstream gap D2b is the distance between two adjacent second downstream ends 123 on the circumferential CD. The downstream gap D2b is greater than the upstream gap D2a. For the second fin 922, the width dimension W2 gradually increases from the second upstream end 122 towards the second downstream end 123, thereby causing the second gap D2 to gradually decrease from the second upstream end 122 towards the second downstream end 123.

[0102] In the first fin 921 and the second fin 922, the first downstream end 113 is opposite to the second upstream end 122. The first downstream end 113 and the second upstream end 122 are arranged along the axial direction AD. The first downstream end 113 and the second upstream end 122 are not offset along the circumferential direction CD. For example, neither the first downstream end 113 nor the second upstream end 122 extends further than the other in the circumferential direction CD. In addition, the width dimension W1b of the first downstream end 113 is the same as the width dimension W2a of the second upstream end 122.

[0103] The third interval D3 is greater than the downstream interval D1b and the upstream interval D2a. Alternatively, the third interval D3 is less than the upstream interval D1a and the downstream interval D2b. The third interval D3 is the distance between the first fin 921 and the second fin 922 along the axial direction AD. Alternatively, the third interval D3 can be less than the downstream interval D1b and the upstream interval D2a, or it can be the same. Alternatively, the third interval D3 can be greater than the upstream interval D1a and the downstream interval D2b, or it can be the same.

[0104] Within the inverter housing 90, a fin flow path 130 is formed by a plurality of inverter fins 92. The fin flow path 130 extends along the outer peripheral surface 910 of the inverter in a direction orthogonal to the radial direction RD. The fin flow path 130 extends along the outer surface of the inverter fins 92 in the axial direction AD and the circumferential direction CD. The fin flow path 130 is open towards the upstream side, downstream side, and outer peripheral side. For example, the fin flow path 130 is open towards the outer peripheral upstream end 910a and outer peripheral downstream end 910b along the axial direction AD. Additionally, the fin flow path 130 is open towards the side opposite to the outer peripheral surface 910 of the inverter.

[0105] The finned flow path 130 has a first flow path 131, a second flow path 132, and a connecting flow path 133. The first flow path 131, the second flow path 132, and the connecting flow path 133 are arranged along the outer peripheral surface 910 of the inverter. The first flow path 131 and the second flow path 132 are arranged along the axial direction AD. The first flow path 131 is located closer to the upstream end 910a of the outer periphery than the second flow path 132. The connecting flow path 133 is disposed between the first flow path 131 and the second flow path 132 along the axial direction AD. The connecting flow path 133 connects the first flow path 131 and the second flow path 132.

[0106] The first flow path 131 is the space between two adjacent first fins 921 on the circumferential CD. The first flow path 131 is formed by two opposing first fin surfaces 111 on the circumferential CD. The first flow path 131 extends along the inverter outer peripheral surface 910 and the first fin surfaces 111 in the axial direction AD.

[0107] The first flow path 131 is open to the upstream side, downstream side, and outer periphery. The first flow path 131 has a first upstream opening 131a and a first downstream opening 131b. The first upstream opening 131a opens the first flow path 131 to the upstream side. The first upstream opening 131a is located in a position aligned circumferentially CD with the first upstream end 112. The first downstream opening 131b opens the first flow path 131 to the downstream side. The first downstream opening 131b is located in a position aligned circumferentially CD with the first downstream end 113. The first upstream opening 131a and the first downstream opening 131b are aligned axially AD.

[0108] On the circumferential direction CD, the width of the first flow path 131 is the same as the first interval D1. The width of the first flow path 131 is the largest at the first upstream port 131a. The width of the first upstream port 131a is the same as the interval D1a. The width of the first flow path 131 is the smallest at the first downstream port 131b. The width of the first downstream port 131b is the same as the interval D1b.

[0109] The cross-sectional area of ​​the first flow path 131 gradually decreases from the first upstream outlet 131a towards the first downstream outlet 131b. The cross-sectional area of ​​the first flow path 131 is the area of ​​the first flow path 131 at the section after it is cut along a direction orthogonal to the axial direction AD. Within the first flow path 131, the area of ​​the first upstream outlet S131a is the largest. The area of ​​the first upstream outlet S131a is the open area of ​​the first upstream outlet 131a. The area of ​​the first upstream outlet S131a is sometimes referred to as the cross-sectional area of ​​the first upstream outlet 131a. Within the first flow path 131, the area of ​​the first downstream outlet S131b is the smallest. The area of ​​the first downstream outlet S131b is the open area of ​​the first downstream outlet 131b. The area of ​​the first downstream outlet S131b is sometimes referred to as the cross-sectional area of ​​the first downstream outlet 131b.

[0110] The second flow path 132 is the space between two adjacent second fins 922 on the circumferential CD. The second flow path 132 is formed by two opposing second fin surfaces 121 on the circumferential CD. The second flow path 132 extends along the outer peripheral surface 910 of the inverter and the second fin surface 121 in the axial direction AD.

[0111] The second flow path 132 is open to the upstream side, downstream side, and outer periphery. The second flow path 132 has a second upstream opening 132a and a second downstream opening 132b. The second upstream opening 132a opens the second flow path 132 upstream. The second upstream opening 132a is located in a position aligned circumferentially with the second upstream end 122 along the CD direction. The second downstream opening 132b opens the second flow path 132 downstream. The second downstream opening 132b is located in a position aligned circumferentially with the second downstream end 123 along the CD direction. The second upstream opening 132a and the second downstream opening 132b are aligned axially with the AD direction.

[0112] On the circumferential direction CD, the width of the second flow path 132 is the same as that of the second interval D2. The width of the second flow path 132 is smallest at the second upstream port 132a. The width of the second upstream port 132a is the same as that of interval D2a. The width of the second flow path 132 is largest at the second downstream port 132b. The width of the second downstream port 132b is the same as that of interval D2b.

[0113] The cross-sectional area of ​​the second flow path 132 gradually increases from the second upstream outlet 132a towards the second downstream outlet 132b. The cross-sectional area of ​​the second flow path 132 is the area of ​​the section after cutting the second flow path 132 along a direction orthogonal to the axial direction AD. Within the second flow path 132, the area of ​​the second upstream outlet S132a is the smallest. The area of ​​the second upstream outlet S132a is the open area of ​​the second upstream outlet 132a. The area of ​​the second upstream outlet S132a is sometimes referred to as the cross-sectional area of ​​the second upstream outlet 132a. Within the second flow path 132, the area of ​​the second downstream outlet S132b is the largest. The area of ​​the second downstream outlet S132b is the open area of ​​the second downstream outlet 132b. The area of ​​the second downstream outlet S132b is sometimes referred to as the cross-sectional area of ​​the second downstream outlet 132b.

[0114] In the first flow path 131 and the second flow path 132, the first downstream port 131b and the second upstream port 132a are arranged along the axial direction AD. The first downstream port 131b opens along the axial direction AD towards the outer peripheral downstream end 910b. The first downstream port 131b corresponds to the first opposite port. The second upstream port 132a opens along the axial direction AD towards the outer peripheral upstream end 910a. The second upstream port 132a corresponds to the second opposite port. The first downstream port 131b and the second upstream port 132a are not offset along the circumferential direction CD. For example, neither the first downstream port 131b nor the second upstream port 132a protrudes further along the circumferential direction CD than the other. In addition, the width dimension of the first downstream port 131b is the same as the width dimension of the second upstream port 132a. Furthermore, the area of ​​the first downstream port S131b and the area of ​​the second upstream port S132a are the same.

[0115] The first upstream port 131a and the second downstream port 132b are arranged along the axial direction AD. The first upstream port 131a and the second downstream port 132b are not offset along the circumferential direction CD. For example, neither the first upstream port 131a nor the second downstream port 132b protrudes further than the other in the circumferential direction CD. Furthermore, the width of the first upstream port 131a is the same as the width of the second downstream port 132b. Additionally, the areas of the first upstream port S131a and the second downstream port S132b are the same.

[0116] A connecting flow path 133 connects a plurality of first flow paths 131 and a plurality of second flow paths 132. The connecting flow path 133 extends circumferentially along the CD, spanning the plurality of first flow paths 131. The connecting flow path 133 connects two adjacent first flow paths 131 in the circumferential direction CD. A first downstream outlet 131b is included at the boundary between the connecting flow path 133 and the first flow paths 131. The connecting flow path 133 extends circumferentially along the CD, spanning the plurality of second flow paths 132. The connecting flow path 133 connects two adjacent second flow paths 132 in the circumferential direction CD. A second upstream outlet 132a is included at the boundary between the connecting flow path 133 and the second flow paths 132.

[0117] The connecting flow path 133 is open to the upstream side, downstream side, and outer periphery. The connecting flow path 133 includes the 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 connecting flow path 133 includes the space connecting the first flow path 131 and the second flow path 132. In the axial direction AD, the width of the connecting flow path 133 is the same as the third interval D3. The width of the connecting flow path 133 is greater than the width of the first downstream opening 131b and the width of the second upstream opening 132a. The width of the connecting flow path 133 is less than the width of the first upstream opening 131a and the width of the second downstream opening 132b.

[0118] like Figure 8 As shown, when the propeller airflow Wp flows into the finned flow path 130, mainstream regions R11 and R21, as well as temperature boundary layers R12 and R22, sometimes form within the finned flow path 130. When the inverter housing 90 heats up due to heat generated in the inverter section 170, a temperature difference easily arises between the propeller airflow Wp flowing into the finned flow path 130 and the inverter fins 92. The mainstream regions R11 and R21 are areas where the propeller airflow Wp, with a temperature difference from the inverter fins 92, easily flows. The temperature boundary layers R12 and R22 are areas where the temperature of the propeller airflow Wp easily changes due to heat from the inverter fins 92. The temperature boundary layers R12 and R22 are formed to extend in layers along the outer surface of the inverter fins 92. The temperature boundary layers R12 and R22 are sometimes referred to as temperature boundary regions. The mainstream regions R11 and R21 are sometimes referred to as mainstream temperature regions.

[0119] The propeller wind Wp includes a first propeller wind Wp1. The first propeller wind Wp1 is the propeller wind Wp flowing through the first flow path 131. The first propeller wind Wp1 flows into the first flow path 131 from the first upstream port 131a. The first propeller wind Wp1 flows through the first flow path 131 along the axial direction AD.

[0120] In the first flow path 131, the flow through the first propeller wind Wp1 sometimes forms a first mainstream region R11 and a first temperature boundary layer R12. The first temperature boundary layer R12 is formed to extend in layers along the axial direction AD of the first fin surface 111. For example, in the first temperature boundary layer R12, the thickness of the circumferential direction CD gradually increases from the first upstream opening 131a toward the first downstream opening 131b. The first mainstream region R11 is located on the opposite side of the first fin 921 on the circumferential direction CD, separated by the first temperature boundary layer R12. The first mainstream region R11 is formed between two adjacent first temperature boundary layers R12 on the circumferential direction CD. For example, in the first mainstream region R11, the width of the circumferential direction CD gradually decreases from the first upstream opening 131a toward the first downstream opening 131b.

[0121] likeFigure 9 As shown, the first propeller wind Wp1 includes a first mainstream wind Wp11 and a first boundary wind Wp12. The first mainstream wind Wp11 flows axially AD towards the first downstream outlet 131b in the first mainstream region R11. The first boundary wind Wp12 flows axially AD towards the first downstream outlet 131b in the first temperature boundary layer R12. The first boundary wind Wp12 is prone to temperature rise in the first temperature boundary layer R12. The temperature of the first boundary wind Wp12 is prone to be higher than the temperature of the first mainstream wind Wp11. That is, a temperature difference is easily generated between the first boundary wind Wp12 and the first mainstream wind Wp11.

[0122] like Figure 8 As shown, propeller wind Wp includes second propeller wind Wp2. Second propeller wind Wp2 is propeller wind Wp flowing through second flow path 132. Second propeller wind Wp2 flows into second flow path 132 from second upstream port 132a. Second propeller wind Wp2 flows through second flow path 132 along axis AD.

[0123] In the second flow path 132, the flow via the second propeller wind Wp2 sometimes forms a second mainstream region R21 and a second temperature boundary layer R22. The second temperature boundary layer R22 is formed as a layered extension along the second fin surface 121 in the axial direction AD. For example, in the second temperature boundary layer R22, the thickness of the circumferential direction CD gradually increases from the second upstream opening 132a toward the second downstream opening 132b. The second mainstream region R21 is located on the opposite side of the second fin 922 on the circumferential direction CD, separated by the second temperature boundary layer R22. The second mainstream region R21 is the space between two adjacent second temperature boundary layers R22 on the circumferential direction CD.

[0124] like Figure 9 As shown, the second propeller wind Wp2 includes a second mainstream wind Wp21 and a second boundary wind Wp22. The second mainstream wind Wp21 flows axially AD towards the second downstream outlet 132b in the second mainstream region R21. The second boundary wind Wp22 flows axially AD towards the second downstream outlet 132b in the second temperature boundary layer R22. The second boundary wind Wp22 tends to experience a temperature rise in the second temperature boundary layer R22. The temperature of the second boundary wind Wp22 tends to be higher than that of the second mainstream wind Wp21. That is, a temperature difference easily arises between the second boundary wind Wp22 and the second mainstream wind Wp21.

[0125] For example, consider Comparative Example 1, where the propeller wind Wp in the finned flow path 130 does not generate turbulence such as eddies. Thus, the first boundary wind Wp12 flowing in the first temperature boundary layer R12 continues to flow along the axial direction AD and becomes the second boundary wind Wp22 flowing in the second temperature boundary layer R22. In Comparative Example 1, the first boundary wind Wp12, as the second boundary wind Wp22, experiences a further temperature increase in the second temperature boundary layer R22. Therefore, the temperature difference between the second boundary wind Wp22 and the second mainstream wind Wp21 is likely to be greater 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 tends to thicken in the circumferential direction CD. Furthermore, in this case, the second mainstream region R21 tends to thin in the circumferential direction CD. Therefore, in the second flow path 132, the temperature of the second boundary wind Wp22 is high, which may reduce the heat dissipation effect of the second boundary wind Wp22 on the second fin 922.

[0126] In contrast, in this embodiment, by providing a connecting flow path 133 between the first flow path 131 and the second flow path 132, the propeller wind Wp is prone to turbulence. For example, when the first propeller wind Wp1 flows into the connecting flow path 133 from the first downstream outlet 131b, the first propeller wind Wp1 may detach from the first downstream end 113, causing turbulence. In this case, as the first propeller wind Wp1, the first mainstream wind Wp11 and the first boundary wind Wp12 flow into the connecting flow path 133. The first mainstream wind Wp11 and the first boundary wind Wp12 are easily agitated due to the turbulence generated when flowing into the connecting flow path 133.

[0127] For the connecting flow path 133, the width dimensions of the first downstream outlet 131b, the second upstream outlet 132a, and the connecting flow path 133 are set to values ​​that facilitate the agitation of the first propeller airflow Wp1 flowing into the connecting flow path 133. For example, if the width dimension of the connecting flow path 133 is too small, the first propeller airflow Wp1 flowing into the connecting flow path 133 may sometimes be difficult to agitate. That is, the agitation amount of the first propeller airflow Wp1 may sometimes be insufficient. If the width dimension of the connecting flow path 133 is appropriately large, the first propeller airflow Wp1 flowing into the connecting flow path 133 will be easily agitated. That is, the agitation amount of the first propeller airflow Wp1 is less likely 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 to facilitate the agitation of the first propeller airflow Wp1 flowing into the connecting flow path 133.

[0128] The propeller wind Wp includes a third propeller wind Wp3. The third propeller wind Wp3 is the propeller wind Wp flowing through the connecting flow path 133. The third propeller wind Wp3 includes the first propeller wind Wp1 flowing into the connecting flow path 133 from the first flow path 131. That is, the third propeller wind Wp3 includes a first mainstream wind Wp11 and a first boundary wind Wp12. In the third propeller wind Wp3, the first mainstream wind Wp11 and the first boundary wind Wp12 are easily stirred. Therefore, the temperature of the third propeller wind Wp3 easily becomes uniform in the connecting flow path 133.

[0129] The third propeller wind Wp3 flows into the second flow path 132 from the connecting flow path 133, thus flowing through the second flow path 132 as the second propeller wind Wp2. The third propeller wind Wp3 flowing into the second mainstream region R21 flows through the second mainstream region R21 as the second mainstream wind Wp21. The third propeller wind Wp3 flowing 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 has been homogenized, the temperature of the second mainstream wind Wp21 flowing into the second mainstream region R21 is approximately the same as the temperature of the second boundary wind Wp22 flowing into the second temperature boundary layer R22.

[0130] Therefore, in this embodiment, the temperature of the second boundary wind Wp22 tends to be lower compared to Comparative Example 1. In this case, the second temperature boundary layer R22 tends to be thinner in the circumferential direction CD compared to Comparative Example 1. Furthermore, in this case, the second mainstream region R21 tends to be thicker in the circumferential direction CD compared to Comparative Example 1. Therefore, compared to Comparative Example 1, the heat dissipation effect of the second boundary wind Wp22 on the second fin 922 is improved.

[0131] Next, consider a comparative example 2, in which the finned flow path 130 does not have a second flow path 132 and a connecting flow path 133. In comparative example 2, as... Figure 10 As shown, the comparator fin 921ex is disposed on the outer peripheral surface 910 of the inverter, serving as inverter fin 92. The comparator fin 921ex extends across the inverter section 170 along the axial direction AD. In Comparative Example 2, a comparator flow path 130ex is formed by two adjacent comparator fins 921ex on the circumferential direction CD. The comparator flow path 130ex does not include the flow path corresponding to the connecting flow path 133.

[0132] In the comparison flow path 130ex, the comparison wind Wpex flows along the comparison fin 921ex in the axial direction AD. Within the comparison flow path 130ex, the comparison wind Wpex flows, thus forming the comparison mainstream region Rex1 and the comparison temperature boundary layer Rex2. (As...) Figure 11As shown, the comparative wind Wpex includes the comparative mainstream wind Wpex1 and the 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.

[0133] In the comparison flow path 130ex, the comparison air Wpex flowing in from the upstream side is not easily stirred between the mainstream comparison air Wpex1 and the boundary comparison air Wpex2 before flowing out to the downstream side. Therefore, in the comparison flow path 130ex, the further downstream the comparison air Wpex moves, the greater the temperature difference between the mainstream comparison air Wpex1 and the boundary comparison air Wpex2 tends to be. Therefore, in Comparative Example 2, the further downstream the comparison flow path 130ex, the less effective the comparison air Wpex may be at dissipating heat from the comparison fins 921ex. Furthermore, the heat dissipation effect of the comparison air Wpex on the inverter section 170 may also be insufficient.

[0134] The inverter fins 92 of this embodiment will be summarized and described. For the electric vertical takeoff and landing aircraft eVTOL 10, the requirement for lightweight design is very high. Therefore, for the EPU 50, lightweight design is achieved through miniaturization of the housing such as the inverter housing 90 and reduction of the number of semiconductor components connected in parallel, such as the arm switch 86. Furthermore, to achieve lightweight design of the EPU 50, a cooling structure with low airflow pressure loss and high cooling performance is preferred for the air-cooled housing.

[0135] Furthermore, the EPU 50, as an electric propulsion unit, is a product consisting of an electric motor 61 that drives the propeller 20 and an inverter section 170 that drives the electric motor 61. The electric motor 61 and the inverter section 170 generate losses and heat during operation, thus requiring cooling. In eVTOL 10, to achieve a lightweight design for the EPU 50, air cooling is generally employed. Specifically, airflow generated by the propeller 20 and airflow generated by a fan (different from the propeller 20) pass between heat dissipation fins provided on the outer surface of the EPU 50's housing, thereby dissipating heat from the EPU 50.

[0136] In the inverter unit 80 installed in the eVTOL 10, heat-generating components such as the switching component 175 are sometimes located in one place relative to the mainstream airflow direction, such as the propeller fan Wp. Furthermore, in the inverter unit 80, heat dissipation is sometimes low due to factors such as the thinness of the casing. In light of these situations, it can be concluded that improving the performance of the EPU 50 is more effective in improving localized cooling performance within the casing than in increasing the surface area of ​​the heat dissipation fins such as the inverter fins 92 to improve the heat dissipation of the casing.

[0137] In this embodiment, the inverter fins 92 are arranged in a plurality of segments along the axial direction AD on the inverter housing 90. That is, the inverter fins 92 are divided into first fins 921 and second fins 922. According to this structure, the airflow in the space between the first fins 921 and the second fins 922 is disturbed, thereby facilitating the mixing of high-temperature airflow flowing near the first fins 921 and low-temperature airflow flowing away from the first fins 921. Consequently, the temperature of the airflow flowing near the second fins 922 tends to decrease. That is, the second temperature boundary layer R22 formed along the second fins 922 tends to become thinner. Therefore, the cooling performance of the second fins 922 is improved.

[0138] Furthermore, according to this structure, by dividing it into a first fin 921 and a second fin 922, a non-heat-dissipating area without heat dissipation fins can be established between the first fin 921 and the second fin 922. Therefore, the mass of the inverter fin 92 is reduced to a degree corresponding to that of the non-heat-dissipating area, thereby enabling the EPU 50 to be lightweight.

[0139] Furthermore, the first fin 921 is tapered in shape to reduce the area of ​​the first flow path 131 by aligning it with a heat source such as the inverter section 170. According to this structure, the first propeller airflow Wp1 flows faster in the first flow path 131 closer to the first downstream outlet 131b. That is, the velocity of the first propeller airflow Wp1 tends to increase more easily in the first flow path 131 closer to the inverter section 170. Thus, when the velocity of the first propeller airflow Wp1 increases, the heat transfer coefficient associated with the first flow path 131 tends to increase. Therefore, the heat dissipation performance of the first propeller airflow Wp1 on the inverter housing 90 can be improved. In addition, by increasing the heat transfer coefficient, the thermal conductivity of the first flow path 131 can be improved.

[0140] Furthermore, according to this structure, the first propeller wind Wp1 flowing from the first flow path 131 into the connecting flow path 133 has a relatively high flow velocity, thus making it easier for the first mainstream wind Wp11 and the first boundary wind Wp12 to mix in the connecting flow path 133. In this way, the first flow path 131 becomes narrower as it gets closer to the connecting flow path 133, thereby achieving a structure in which the third propeller wind Wp3 is easily stirred in the connecting flow path 133.

[0141] Furthermore, according to this structure, the closer to the inverter section 170 in the first flow path 131, the faster the flow velocity of the first propeller fan Wp1 tends to increase. Therefore, the heat transfer coefficient of the first propeller fan Wp1 increases, and heat from the inverter section 170 is more easily released from the inverter outer peripheral wall 95 and the first fin 921 to the first propeller fan Wp1. Thus, the heat dissipation performance of the first propeller fan Wp1 on the heat-generating parts can be improved.

[0142] According to the embodiment described so far, the first fin 921 and the second fin 922 are positioned separately in a direction orthogonal to the axial direction AD. In this structure, at a position aligned radially RD with the inverter section 170, the propeller wind Wp flowing in the space between the first fin 921 and the second fin 922 easily generates turbulence such as eddies. Therefore, heat from the inverter section 170 is easily released to the outside of the inverter housing 90 via 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 of the propeller wind Wp on the outside of the inverter housing 90 at a position aligned radially RD with the inverter section 170, the increase in overall pressure loss of the fin flow path 130 can be suppressed. Therefore, insufficient propeller airflow Wp flowing through the finned flow path 130 can be suppressed, while the heat dissipation effect of propeller airflow Wp on inverter section 170 can be improved. As described above, in EPU 50, the heat dissipation effect of inverter housing 90 can be improved by inverter fins 92.

[0143] According to this embodiment, for two adjacent first fins 921 on the circumferential CD, the first interval D1 gradually decreases towards the downstream end 910b of the outer periphery. In this structure, the width of the first flow path 131 is smaller closer to the inverter section 170. Therefore, in the first flow path 131, the flow velocity of the first propeller wind Wp1 tends to increase closer to the inverter section 170. Thus, at the position where it overlaps with the inverter section 170 along the axial direction AD, the cooling effect of the first propeller wind Wp1 can be locally improved.

[0144] According to this embodiment, the circumferential width dimension W1 of the first fin 921 gradually increases towards the downstream outer peripheral end 910b. That is, the first fin 921 is an expanding fin. Therefore, it is possible to achieve a structure in which the width dimension of the first flow path 131 is smaller closer to the downstream outer peripheral end 910b. In other words, it is possible to achieve a structure in which the cooling effect of the first propeller fan Wp1 is locally improved relative to the installation position of the inverter section 170.

[0145] According to this embodiment, in the finned flow path 130, the first downstream port 131b and the second upstream port 132a are arranged along the axial direction AD. In this structure, the propeller airflow Wp flowing into the connecting flow path 133 from the first downstream port 131b is prone to turbulence, and on the other hand, the propeller airflow Wp flowing into the connecting flow path 133 from the first downstream port 131b is prone to flowing out from the second upstream port 132a. Therefore, in the connecting flow path 133, the cooling effect of the inverter section 170 is improved due to the turbulence of the propeller airflow Wp, and on the other hand, the excessive increase in pressure loss in the finned flow path 130 due to the presence of the connecting flow path 133 can be suppressed. Therefore, by means of both the turbulence generated by the propeller airflow Wp and the high speed of the propeller airflow Wp, the heat dissipation effect of the inverter housing 90 can be improved.

[0146] According to this embodiment, the switching component 175 is disposed on the inner peripheral surface 913 of the inverter. Furthermore, the first fin 921 and the second fin 922 extend axially in the AD direction from a position aligned radially with the switching component 175 along the RD direction. In this structure, the space between the first fin 921 and the second fin 922, i.e., the connecting flow path 133, is disposed at a position aligned radially with the switching component 175 along the RD direction. Therefore, in the connecting flow path 133, the improved cooling performance resulting from the localized turbulence of the propeller wind Wp can be applied to the switching component 175.

[0147] According to this embodiment, an inverter section 170 is housed as a heat-generating unit within the inverter housing 90. In this structure, the temperature of the inverter device 80 can be prevented from rising excessively due to the heat generated in the inverter section 170 by the inverter fins 92.

[0148] According to this embodiment, the EPU 50 is used to drive the eVTOL 10 in flight. In this structure, when the eVTOL 10 is flying under the drive of the EPU 50, the inverter fins 92 can prevent the EPU 50 from overheating due to insufficient heat dissipation from the inverter housing 90. Therefore, the safety of the eVTOL 10 can be improved by the inverter fins 92.

[0149] <Second Implementation>

[0150] In the first embodiment described above, the width dimension W1b of the first downstream end 113 is the same as the width dimension W2a of the second upstream end 122. In contrast, in the second embodiment, the width dimension W2a of the second upstream end 122 is greater than the width dimension W1b of the first downstream end 113. The structures, functions, and effects in the second embodiment that are not specifically described are the same as those in the first embodiment. The description in the second embodiment focuses on the points that differ from the first embodiment.

[0151] like Figure 12As shown, in this embodiment, the second outer peripheral fin is a parallel fin. Among the plurality of inverter fins 92, a second parallel fin 922A is included as the second outer peripheral fin. The shape of the second parallel fin 922A differs from that of the second fin 922 in the first embodiment described above. In the second parallel fin 922A, a pair of second fin surfaces 121 extend parallel to each other along the axial direction AD. The pair of second fin surfaces 121 extend parallel to each other along 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 is the same as the width dimension W2b of the second downstream end 123. The second parallel fin 922A is sometimes referred to as a parallel fin or a straight fin.

[0152] For two adjacent second parallel fins 922A on the circumferential CD, the second spacing D2 is uniform. For example, between two adjacent second parallel fins 922A on the circumferential CD, the upstream end spacing D2a and the downstream end spacing D2b are the same. Furthermore, the width dimension of the second flow path 132 is uniform. For example, the width dimension of the second upstream opening 132a is the same as the width dimension of the second downstream opening 132b. Moreover, the cross-sectional area of ​​the second flow path 132 is uniform. For example, the area of ​​the second upstream opening S132a is the same as the area of ​​the second downstream opening S132b.

[0153] The first downstream end 113 and the second upstream end 122 are offset along the circumferential direction CD due to their different width dimensions. 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 extends from the second upstream end 122 to at least one side of the circumferential direction CD. For example, the first downstream end 113 extends from the second upstream end 122 to both sides of the circumferential direction CD. The first downstream end 113 protrudes to both sides of the second upstream end 122 along the circumferential direction CD on one side and the other side. The first downstream end 113 corresponds to the first opposite end. The second upstream end 122 corresponds to the second opposite end.

[0154] The width of the first downstream port 131b is different from the width of the second upstream port 132a. For example, the width of the second upstream port 132a is greater than the width of the first downstream port 131b. The area of ​​the first downstream port S131b is different from the area of ​​the second upstream port S132a. For example, the area of ​​the second upstream port S132a is greater than the area of ​​the first downstream port S131b.

[0155] The second parallel fin 922A will be summarized below. In the EPU 50 installed in the eVTOL 10, in addition to heat dissipation performance, the pressure loss of the refrigerant flowing between the heat dissipation fins is also an important performance characteristic. To address this, in the second parallel fin 922A, the second upstream end 122 is thinner than the first downstream end 113 in the circumferential direction CD. By thinning the second parallel fin 922A, the cross-sectional area of ​​the second flow path 132 is increased, thereby improving the pressure loss in the second flow path 132. Furthermore, by having two opposing second fin surfaces 121 extending parallel to each other along the axial direction AD across the second flow path 132, the pressure loss in the second flow path 132 can be further improved.

[0156] Of the two heat dissipation fins arranged along the axial direction AD, the first fin 921, serving as the upstream heat dissipation fin, is an expanding fin, thus increasing the flow velocity of the propeller airflow Wp flowing in the first flow path 131, which is the upstream path. Furthermore, the second parallel fin 922A, serving as the downstream heat dissipation fin, is thinner than the first fin 921. Therefore, the propeller airflow Wp, with its flow velocity increased by the first fin 921, can generate a faster flow at the fin segment due to its inertia. Thus, mixing of the propeller airflow Wp can be promoted at the fin segment. The fin segment is the part of the inverter fin 92 that is segmented. For example, the fin segment is the area between the upstream fins such as the first fin 921 and the downstream fins such as the second parallel fin 922A.

[0157] The second parallel fin 922A can be made thinner than the first fin 921, thus making the second parallel fin 922A lighter than the first fin 921. In this way, by reducing the fin mass to a degree corresponding to the lightness of the second parallel fin 922A, it is possible to contribute to the lightness of the EPU 50 and the inverter housing 90.

[0158] According to this embodiment, the first downstream port 131b and the second upstream port 132a are offset along the circumferential direction CD. In this structure, it is less likely that the propeller airflow Wp flowing into the connecting flow path 133 from the first downstream port 131b will flow out of the connecting flow path 133 to the first upstream port 131a without being stirred. For example, when the propeller airflow Wp flows into the connecting flow path 133 from the first downstream port 131b, it is easily detached from the first downstream end 113 and thus stirred in the connecting flow path 133. Therefore, temperature differences are less likely to occur in the connecting flow path 133. Therefore, it is possible to suppress fluctuations in the heat dissipation effect of the propeller airflow Wp on the inverter section 170 depending on the location of the inverter section 170.

[0159] 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 structure, the area of ​​the second upstream outlet S132a is smaller than the area of ​​the first downstream outlet S131b. Therefore, the propeller airflow Wp easily flows from the connecting flow path 133 to the second upstream outlet 132a. That is, for the propeller airflow Wp flowing from the first downstream outlet 131b to the second upstream outlet 132a via the connecting flow path 133, pressure loss can be reduced.

[0160] <Third Implementation Method>

[0161] In the first embodiment described above, the first flow path 131 and the second flow path 132 are arranged along the axial direction AD. In contrast, in the third embodiment, the first flow path 131 and the second flow path 132 are formed at a position offset along the circumferential direction CD. The structures, functions, and effects in the third embodiment, unless otherwise specified, are the same as in the first embodiment. In the third embodiment, the description will focus on the points that differ from the first embodiment.

[0162] like Figure 13 As shown, the first fin 921 and the second fin 922 are offset along the circumferential direction CD. That is, the first fin 921 and the second fin 922 are offset along the circumferential direction CD. The first fin 921 is located in a position aligned with the second flow path 132 along the axial direction AD. The second fin 922 is located in a position aligned with the first flow path 131 along the axial direction AD. The first flow path 131 and the second flow path 132 are separated in the circumferential direction CD. The first downstream port 131b and the second upstream port 132a are located in a position separated in the circumferential direction CD. In addition, a portion of the first downstream port 131b and a portion of the second upstream port 132a may also be aligned along the axial direction AD.

[0163] The first downstream end 113 and the second upstream end 122 are offset along the circumferential direction CD due to their different positions. For example, a portion of the first downstream end 113 and a portion of the second upstream end 122 are aligned along the axial direction AD. The first downstream end 113 is positioned across two adjacent second upstream ends 122 on the circumferential direction CD. The first downstream end 113 is positioned aligned along the axial direction AD with the second upstream opening 132a. The second upstream end 122 is positioned across two adjacent first downstream ends 113 on the circumferential direction CD. The second upstream end 122 is positioned aligned along the axial direction AD with the first downstream opening 131b.

[0164] According to this embodiment, the second upstream end 122 is positioned along the axial direction AD with the first downstream outlet 131b. In this structure, the propeller air Wp flowing into the connecting flow path 133 from the first downstream outlet 131b advances towards the second upstream end 122. The propeller air Wp approaches or collides with the second upstream end 122, thereby promoting mixing and stirring of the propeller air Wp in the connecting flow path 133. Therefore, the temperature of the propeller air Wp in the connecting flow path 133 can be homogenized.

[0165] Furthermore, in this embodiment, the width of the connecting flow path 133 can be smaller than the width of the first downstream port 131b and the width of the second upstream port 132a. That is, the cross-sectional area of ​​the connecting flow path 133 can also be smaller than the area of ​​the first downstream port S131b and the area of ​​the second upstream port S132a. In this structure, compared with the first downstream port 131b and the second upstream port 132a, the connecting flow path 133 becomes a throttling state for the fin flow path 130. Therefore, in the structure where the first downstream end 113 and the second upstream end 122 are offset along the circumferential direction CD, the propeller air Wp flowing into the connecting flow path 133 from the first downstream port 131b tends to increase in velocity when flowing along the circumferential direction CD within the connecting flow path 133. Therefore, at the position where it is arranged radially RD with the inverter section 170, the velocity of the propeller air Wp increases, thereby improving the heat dissipation performance of the propeller air Wp on the inverter section 170.

[0166] <Fourth Implementation>

[0167] In the fourth embodiment, the inverter housing 90 is covered from the outer periphery by a conduit member. The structures, functions, and effects not specifically described in the fourth embodiment are the same as in the third embodiment described above. The fourth embodiment will be described focusing on the differences from the third embodiment.

[0168] like Figure 14 As shown, the EPU 50 has an outer peripheral conduit 200. The outer peripheral conduit 200 covers the inverter housing 90 from the outer peripheral side. The outer peripheral conduit 200 is sometimes referred to as a conduit component or outer cylinder. The outer peripheral conduit 200 has a conduit body 201 and conduit fins 202. The conduit body 201 and conduit fins 202 are formed of a resin material or the like. The conduit body 201 and conduit fins 202 are thermally conductive. Alternatively, the conduit body 201 and conduit fins 202 may also be formed of a metallic material.

[0169] The duct body 201 is cylindrical and extends axially AD. The duct body 201 extends circumferentially CD, spanning multiple inverter fins 92. The duct body 201 is disposed on the outer periphery of the inverter outer peripheral surface 910, passing over the inverter fins 92. The duct body 201 covers the inverter outer peripheral surface 910 from the outer periphery. The duct body 201 is located radially RD near or in contact with the inverter fins 92. A finned flow path 130 is formed between the inverter outer peripheral surface 910 and the duct body 201. The duct body 201 forms a finned flow path 130 between itself and the inverter outer peripheral surface 910. The duct body 201 corresponds to the duct section, and the finned flow path 130 corresponds to the outer peripheral flow path.

[0170] The pipe body 201 has an outer circumferential surface 201a and an inner circumferential surface 201b. The outer circumferential surface 201a and the inner circumferential surface 201b are formed in an annular shape and extend along the axial direction AD. The outer circumferential surface 201a is the outer circumferential surface of the pipe body 201. The inner circumferential surface 201b is the inner circumferential surface of the pipe body 201. The inner circumferential surface 201b is opposite to the outer circumferential surface 910 of the inverter, separated by inverter fins 92. The fin flow path 130 is formed by the inner circumferential surface 201b and the outer circumferential surface 910 of the inverter.

[0171] Pipe fins 202 are disposed on the inner circumferential surface 201b of the pipe. The pipe fins 202 are plate-shaped and extend in a direction orthogonal to the circumferential direction CD. The pipe fins 202 extend from the inner circumferential surface 201b of the pipe towards the outer circumferential surface 910 of the inverter. The pipe fins 202 are protrusions projecting inward from the inner circumferential surface 201b of the pipe. The pipe fins 202 extend axially AD along the inner circumferential surface 201b of the pipe. Multiple pipe fins 202 are arranged along the inner circumferential surface 201b of the pipe in the circumferential direction CD.

[0172] At least a portion of the duct fin 202 is disposed between two adjacent inverter fins 92 on the circumferential CD. The duct fin 202 is positioned so that it enters the space between two adjacent inverter fins 92 on the circumferential CD from the outer peripheral side. That is, the duct fin 202 is positioned so that it enters the fin flow path 130 from the outer peripheral side. The duct fin 202 and the inverter fins 92 are arranged alternately on the circumferential CD.

[0173] like Figures 15-17As shown, the pipe fin 202 has a pair of pipe fin surfaces 203. The pipe fin surfaces 203 are the plate surfaces of the pipe fin 202. The pipe fin surfaces 203 extend in a direction orthogonal to the circumferential direction CD, and the pair of pipe fin surfaces 203 are arranged along the circumferential direction CD. The pipe fin surfaces 203 are also the sides of the pipe fin 202, sometimes referred to as fin sides. The pipe 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 arranged along the axial direction AD. For example, the upstream fin surface 202a extends upstream from the downstream fin surface 202b.

[0174] The pipe fin 202 has an upstream end 204 and a downstream end 205 as a pair of ends arranged along the axial direction AD. The upstream end 204 is the upstream end of the pipe fin 202. The downstream end 205 is the downstream end of the pipe fin 202.

[0175] The middle portion of the axial direction AD of the pipe fin 202 becomes a bulging shape along the circumferential direction CD. In the circumferential direction CD, the width dimension of the pipe fin 202 gradually decreases from the middle portion toward the upstream end 204 and the downstream end 205 of the fin, respectively.

[0176] At least one of the upstream fin surface 202a and the downstream fin surface 202b is inclined circumferentially towards CD relative to the motor axis Cm. For example, the upstream fin surface 202a is inclined to one side of the motor axis Cm in the circumferential direction towards CD. The downstream fin surface 202b is inclined to the other side of the motor axis Cm in the circumferential direction towards CD. The upstream fin surface 202a and the downstream fin surface 202b extend straight along the axial direction AD. The upstream fin surface 202a and the downstream fin surface 202b are conical surfaces.

[0177] like Figure 15 As shown, the duct fin 202 has a shape where the width of the circumferential fin CD gradually tapers towards the inner circumference. The duct fin 202 is equivalent to a conical fin. The width dimension of the duct fin 202 continuously decreases towards the outer circumferential surface 910 of the inverter. The distance between a pair of duct fin surfaces 203 gradually decreases towards the front end of the duct fin 202. The duct fin surface 203 is inclined circumferentially towards the CD relative to the outer circumferential centerline Crd. The duct fin surface 203 extends straight towards the inner circumference. The duct fin surface 203 is a conical surface.

[0178] Additionally, the pipe fins 202 may taper progressively towards the inner circumference. For example, the pipe fin surface 203 may also be a stepped surface. Furthermore, the pipe fin surface 203 may be curved in a manner that is recessed or bulged in the circumferential direction CD. For example, the pipe fin surface 203 may also be a curved surface or a bent surface.

[0179] In this embodiment, the inverter fins 92 and the duct fins 202 also have a tapering shape at the front end. The inverter fins 92 have a shape in which the width of the circumferential direction CD gradually tapers towards the inner circumference. The first fin surface 111 and the second fin surface 121 are inclined in the circumferential direction CD relative to the outer circumferential centerline Crd. The inclination angle of the first fin surface 111 and the second fin surface 121 relative to the outer circumferential centerline Crd is the same as the inclination angle of the duct fin surface 203 relative to the outer circumferential centerline Crd. That is, the duct fin surface 203 extends radially RD parallel to the first fin surface 111 and the second fin surface 121.

[0180] like Figure 17 As shown, a pipe fin 202 is disposed in a fin flow path 130. At least a portion of the pipe fin 202 is disposed in a connecting flow path 133 between a first downstream port 131b and a second upstream port 132a. The pipe fin 202 is positioned to enter at least one of the first flow path 131 and the second flow path 132 from the connecting flow path 133. For example, the pipe fin 202 extends axially AD such that it spans the first flow path 131 and the second flow path 132 via the connecting flow path 133. In the pipe fin 202, the upstream end 204 is disposed in the first flow path 131, and the downstream end 205 is disposed in the second flow path 132.

[0181] The pipe fin 202 is clamped at least one of the following locations on the circumferential CD: between two adjacent first fins 921 and between two adjacent second fins 922 on the circumferential CD. For example, the pipe fin 202 is disposed between two adjacent first fins 921 and between two adjacent second fins 922 on the circumferential CD. The pipe fin 202 corresponds to the fin clamping portion.

[0182] like Figure 16 As shown, at least a portion of the duct fin 202 is disposed at a position aligned with the inverter section 170 along the axial direction AD. The duct fin 202 is disposed at a position aligned with the switching component 175 along the axial direction AD. For example, the duct fin 202 is disposed at a position where it does not extend from the switching component 175 along the axial direction AD. The duct fin 202 is entirely aligned with the switching component 175 along the axial direction AD.

[0183] like Figure 17As shown, in this embodiment, both the first and second outer peripheral fins are parallel fins. Similar to the second embodiment described above, among the plurality of inverter fins 92, a second parallel fin 922A is included as the second outer peripheral fin. Among the plurality of inverter fins 92, a first parallel fin 921A is included as the first outer peripheral fin. The shape of the first parallel fin 921A differs from that of the first fin 921 in the first embodiment described above. In the first parallel fin 921A, a pair of first fin surfaces 111 extend parallel to each other along the axial direction AD. The pair of first fin surfaces 111 extend parallel to each other along 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 is the same as the width dimension W1b of the first downstream end 113. The first parallel fin 921A is sometimes referred to as a parallel fin or a straight fin.

[0184] For two adjacent first parallel fins 921A on the circumferential CD, the first interval D1 is uniform. For example, between two adjacent first parallel fins 921A on the circumferential CD, the upstream end interval D1a and the downstream end interval D1b are the same. Furthermore, the width dimension of the first flow path 131 is uniform. For example, the width dimension of the first upstream opening 131a is the same as the width dimension of the first downstream opening 131b. Moreover, the cross-sectional area of ​​the first flow path 131 is uniform. For example, the area of ​​the first upstream opening S131a is the same as the area of ​​the first downstream opening S131b.

[0185] In the first flow path 131, the distance between the first parallel fin 921A on the circumferential direction CD and the duct fin 202 gradually decreases along the axial direction AD from the upstream end 204 of the fin towards the first downstream opening 131b. Therefore, even in a structure where two adjacent first fin surfaces 111 on the circumferential direction CD extend parallel to each other along the axial direction AD, the cross-sectional area of ​​the first flow path 131 gradually decreases towards the first downstream opening 131b. For the first propeller wind Wp1, passing between the first parallel fin 921A and the duct fin 202 and approaching the first downstream opening 131b, the flow velocity easily increases.

[0186] In the second flow path 132, the distance between the second parallel fin 922A on the circumferential direction CD and the pipe fin 202 gradually increases from the second upstream opening 132a toward the downstream end 205 of the fin in the axial direction AD. Therefore, even in a structure where two adjacent second fin surfaces 121 on the circumferential direction CD extend parallel to each other along the axial direction AD, the cross-sectional area of ​​the second flow path 132 gradually increases toward the downstream end 205 of the fin.

[0187] The outer peripheral duct 200 is described in summary. By providing the outer peripheral duct 200 on the outer periphery of the inverter housing 90, the propeller wind Wp, which flows axially AD as refrigerant, is guided by the outer peripheral duct 200. In the inverter unit 80, by providing a duct fin 202 between 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 heat dissipation performance around the fin segment can be improved by the duct fin 202.

[0188] The inverter fins 92 become thinner closer to the tip. That is, the inverter fins 92 become thinner along the circumferential direction CD the further away from the outer peripheral surface 910 of the inverter. Therefore, in the first interval D1 and the second interval D2, the areas further away from the outer peripheral surface 910 of the inverter are larger. In the fin flow path 130, the cross-sectional area of ​​the area farther from the outer peripheral surface 910 of the inverter is larger than the cross-sectional area of ​​the area closer to the outer peripheral surface 910 of the inverter.

[0189] In contrast, the duct fins 202 become thinner closer to the fin tip. That is, the duct fins 202 become thinner closer to the outer peripheral surface 910 of the inverter. Therefore, in the duct fins 202, the cross-sectional area of ​​the portion farther from the outer peripheral surface 910 of the inverter is larger than the cross-sectional area of ​​the portion closer to the outer peripheral surface 910 of the inverter. Therefore, in the actual area through which the propeller wind Wp actually flows in the fin flow path 130, due to the presence of the duct fins 202, the cross-sectional area of ​​the region farther from the outer peripheral surface 910 of the inverter decreases in a manner that is close to the cross-sectional area of ​​the region closer to the outer peripheral surface 910 of the inverter. Thus, regardless of the height of the inverter fins 92 and other heat dissipation fins, a uniform flow can be formed in the fin flow path 130.

[0190] According to this embodiment, at least a portion of the duct fins 202 is disposed between the first downstream port 131b and the second upstream port 132a. In this structure, when the propeller airflow Wp flows into the connecting flow path 133 from the first downstream port 131b, the propeller airflow Wp is easily agitated by approaching or colliding with the duct fins 202. Therefore, for the propeller airflow Wp, the turbulence such as eddies generated by the presence of the duct fins 202 can improve the heat dissipation effect on the inverter section 170.

[0191] According to this embodiment, the duct fins 202 extend radially RD from the duct body 201 toward the outer peripheral surface 910 of the inverter. In this structure, the outer peripheral duct 200 is mounted on the inverter housing 90, thereby the duct fins 202 are disposed in the fin flow path 130. Therefore, even if, due to factors such as the manufacturing of the inverter housing 90, it is difficult to position the duct fins 202 in the fin flow path 130 at a position on the outer peripheral surface 910 of the inverter, the duct fins 202 can still be configured. Therefore, the degree of freedom in positioning the fin clamping portions, such as the duct fins 202, can be increased.

[0192] According to this embodiment, the circumferential width CD of the duct fin 202 gradually decreases toward the outer peripheral surface 910 of the inverter. Therefore, even if the width dimension of the fin flow path 130 is smaller closer to the outer peripheral surface 910 of the inverter, the width dimension of the actual area in the fin flow path 130 can be made uniform in the radial direction RD.

[0193] <Other Implementation Methods>

[0194] This disclosure is not limited to the illustrated embodiments. This disclosure includes illustrated embodiments and modifications made by those skilled in the art based thereon. For example, this disclosure is not limited to the combinations of components and elements shown in the embodiments, and various modifications can be made to implement it. This disclosure can be implemented in various combinations. This disclosure may have additional portions that can be added to the embodiments. This disclosure includes structures that omit components and elements of the embodiments. This disclosure includes substitutions or combinations of components and elements between one embodiment and another. The technical scope of this disclosure is not limited to the description of the embodiments. The technical scope of this disclosure should be understood as expressed by the description of the claims, and also includes all modifications in the meaning and scope of equivalence to the description of the claims.

[0195] In the above embodiments, inverter fins such as inverter fins 92 can be arbitrarily disposed in the inverter housing 90 or the like. Among the plurality of inverter fins 92, at least one inverter fin 92 can be configured as an equivalent to an outer peripheral fin. Furthermore, first outer peripheral fins such as first fins 921 and second outer peripheral fins such as second fins 922 can be arbitrarily disposed in the housing. Among the plurality of first fins 921, at least one first fin 921 can be configured as an equivalent to a first outer peripheral fin. Among the plurality of second fins 922, at least one second fin 922 can be configured as an equivalent to a second outer peripheral fin. Additionally, at least a portion of the outer peripheral fins, the first outer peripheral fins, and the second outer peripheral fins can be respectively disposed on the upstream surface 911 and the downstream surface 912 of the inverter.

[0196] In the above embodiments, the first and second outer peripheral fins can be of any shape. For example, in the first embodiment, the first fin 921 can be a contracted fin or a parallel fin. Similarly, the second fin 922 can be an expanded fin or a parallel fin. Furthermore, the shapes of the multiple first outer peripheral fins can be different. Likewise, the shapes of the multiple second outer peripheral fins can also be different. In addition, the first and second outer peripheral fins can be inclined circumferentially towards CD relative to the motor axis Cm.

[0197] In the above embodiments, the first and second outer peripheral fins can be in any positional relationship as long as they extend in the axial direction AD from the position where they overlap with the heat-generating parts such as the inverter section 170 along the radial direction RD. The first and second outer peripheral fins only need to be separated in a direction orthogonal to the radial direction RD. For example, in the first embodiment described above, the first fin 921 and the second fin 922 only need to be separated in the circumferential direction CD. In this structure, a portion of the first fin 921 and a portion of the second fin 922 can also be arranged in the circumferential direction CD. For example, the first downstream end 113 can be provided at a position closer to the downstream side than the second upstream end 122. That is, the first flow path 131 and the second flow path 132 can be directly connected without passing through the connecting flow path 133.

[0198] In the above embodiments, the relationship between the width dimension W1b of the first downstream end 113 and the width dimension W2a of the second upstream end 122 can be arbitrary. For example, the width dimension W1b of the first downstream end 113 can be larger than the width dimension W2a of the second upstream end 122. Furthermore, the relationship between the area of ​​the first downstream outlet S131b and the area of ​​the second upstream outlet S132a can be arbitrary. For example, the area of ​​the first downstream outlet S131b can be larger than the area of ​​the second upstream outlet S132a.

[0199] In the above embodiments, the fin clamping portion, such as the pipe fin 202, can be of any shape. For example, in the fourth embodiment described above, the pipe fin 202 can extend in a plate-like shape along the circumferential direction CD. Alternatively, the pipe fin 202 can also be formed in a cylindrical, prismatic, or tubular shape.

[0200] In the above embodiments, the fin clamping portion can be arbitrarily disposed in the fin flow path 130. For example, in the fourth embodiment described above, the duct fin 202 can be disposed on the outer peripheral surface 910 of the inverter. In this structure, the protrusion disposed on the outer peripheral surface 910 of the inverter is the duct fin 202, which is equivalent to the fin clamping portion.

[0201] In each of the above embodiments, surface-mounted components can be arbitrarily arranged inside the housing. For example, in the first embodiment described above, the capacitor component 176 and the filter component 177 can be provided as surface-mounted components. Alternatively, the heat-generating part may not have surface-mounted components. In this structure, it is preferable to arrange multiple heat-generating components such as the switching component 175 along the inner peripheral surface 913 of the inverter.

[0202] In the above embodiments, the outer peripheral fins can be motor fins 72. For example, in the case of a propeller wind Wp, the motor unit 60 can be provided upstream of the inverter unit 80. In this structure, the motor 61, motor stator 62, motor rotor 63, etc., correspond to the heat-generating parts, and the motor housing 70 corresponds to the housing. Moreover, the motor fins 72 are provided on the motor housing 70 as outer peripheral fins.

[0203] In the above embodiments, the motor 61 and the inverter unit 170 can be housed 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. Within the common housing, the motor 61 and the inverter unit 170 function as heat-generating components.

[0204] In the above embodiments, the motor 61 may not be a dual-rotor motor. For example, the motor 61 may be a single-rotor motor with one rotor. Furthermore, the motor 61 may not be an axially spaced motor. For example, the motor 61 may be a radially spaced motor. In this motor 61, the motor stator 62 and the motor rotor 63 are arranged radially RD.

[0205] In the above embodiments, the airflow of the propeller wind Wp can be generated arbitrarily. For example, an air supply device can be provided to the EPU 50, which is a fan or the like that generates airflow along the axial direction AD. The air supply device may or may not be included in the EPU 50. In addition, the airflow along the axial direction AD may also be the flight wind generated accompanying the flight of the eVTOL 10.

[0206] In the above embodiments, in the eVTOL 10, at least one propeller 20 can be driven by at least one EPU 50. For example, one propeller 20 can be driven by multiple EPUs 50, or multiple propellers 20 can be driven by one EPU 50.

[0207] In the above embodiments, the aircraft equipped with the EPU 50 can be electrically powered and does not necessarily have to be a vertical takeoff and landing aircraft. For example, the aircraft can also be an electric aircraft capable of taking off and landing while taxiing. In addition, the aircraft can also be a rotary-wing aircraft or a fixed-wing aircraft. The aircraft can also be an unmanned aircraft without passengers.

[0208] In the above embodiments, the mobile body equipped with the EPU 50 can be moved by the rotation of the rotating body, and does not necessarily have to be an aircraft. For example, the mobile body can be a vehicle, a ship, construction machinery, or agricultural machinery. For example, if the mobile body is a vehicle or construction machinery, the rotating body is a wheel for movement, and the output shaft is an axle. If the mobile body is a ship, the rotating body is a propeller for propulsion, and the output shaft is a propeller shaft.

[0209] (Disclosure of technical concepts)

[0210] This specification discloses several technical concepts described in the following list of items. Some items are sometimes described by selectively referencing a previous item in a multiple dependent form in a subsequent item. Furthermore, some items are sometimes described by referring to another multiple dependent form of an item. These items described in multiple dependent forms define several technical concepts.

[0211] (Technical Concept 1)

[0212] A driving device (50) is electrically driven and includes: The heating element (170) heats up when energized; A housing (90) having an outer peripheral surface (910) extending axially (AD) and housing the heating element; and The outer peripheral fins (92) extend axially along the outer peripheral surface of the outer shell, and a plurality of them are arranged along the outer peripheral surface of the outer shell in the circumferential direction (CD) of the outer shell, and release the heat of the heating element to the outside of the outer shell. The outer peripheral surface of the outer casing has a first end face (910a) and a second end face (910b), which are a pair of ends arranged along the axial direction. The plurality of said peripheral fins have: The first outer peripheral fin (921, 921A) extends from a position aligned radially (RD) with the heating element along the outer shell towards the first end of the first surface and the second end of the second surface; and The second outer peripheral fin (922, 922A) is disposed at a position separate from the first outer peripheral fin in a direction orthogonal to the radial direction, and extends from a position arranged radially with the heating element to the second end of the first surface end and the second surface end.

[0213] (Technical Concept 2)

[0214] In the drive device described in Technical Concept 1, the interval (D1) between two adjacent first outer peripheral fins in the circumferential direction gradually decreases in the axial direction toward the end of the second surface.

[0215] (Technical Concept 3)

[0216] In the drive device described in technical concept 1 or 2, the first peripheral fin includes an expanding fin (921) whose circumferential width (W1) gradually expands toward the end of the second surface.

[0217] (Technical Concept 4)

[0218] In any of the driving devices described in technical concepts 1 to 3, a first opposing opening (131b) is formed between two adjacent first outer peripheral fins in the circumferential direction, which opens toward the end side of the second surface in the axial direction. Between two adjacent second outer peripheral fins in the circumferential direction, a second opposing opening (132a) is formed that opens in the axial direction toward the end side of the first surface. The first and second opposite ports are arranged along the axial direction.

[0219] (Technical Concept 5)

[0220] In the driving device described in Technical Concept 4, a fin clamping portion (202) is included, which extends along the radial direction and is at least partially disposed between the first opposing opening and the second opposing opening, and is clamped at at least one of the two first peripheral fins adjacent in the circumferential direction and the two second peripheral fins adjacent in the circumferential direction.

[0221] (Technical Concept 6)

[0222] In the drive device described in Technical Concept 5, a pipe section (201) is provided on the outer peripheral side of the outer peripheral surface of the housing in such a way that it covers the outer peripheral surface of the housing from the outer peripheral side, and an outer peripheral flow path (130) for gas flow is formed between the pipe section (201) and the outer peripheral surface of the housing. The fin clamping portion extends radially from the pipe portion toward the outer peripheral surface of the outer shell.

[0223] (Technical Concept 7)

[0224] In the drive device described in technical concept 5 or 6, the fin clamping part includes a tapered fin (202) whose circumferential width gradually decreases toward the outer peripheral surface of the outer shell.

[0225] (Technical Concept 8)

[0226] In any of the driving devices described in technical concepts 1 to 7, the first outer peripheral fin and the second outer peripheral fin are separated in the axial direction. The first peripheral fin has a first opposing end (113) that serves as the end of the second surface. The second peripheral fin has a second opposing end (122) that serves as the end of the first surface. The first and second opposite ends are offset in the circumferential direction.

[0227] (Technical Concept 9)

[0228] In any of the driving devices described in technical concepts 1 to 8, the first outer peripheral fin and the second outer peripheral fin are separated in the axial direction. The first peripheral fin has a first opposing end (113) that serves as the end of the second surface. The second peripheral fin has a second opposing end (122) that serves as the end of the first surface. The first and second opposite ends are arranged along the axial direction. In the circumferential direction, the width dimension (D2a) of the second opposite end is smaller than the width dimension (D1b) of the first opposite end.

[0229] (Technical Concept 10)

[0230] In any of the driving devices described in technical concepts 1 to 9, the first outer peripheral fin and the second outer peripheral fin are separated in the axial direction. Between two adjacent first outer peripheral fins in the circumferential direction, a first opposing opening (131b) is formed that opens in the axial direction toward the end side of the second surface. The second peripheral fin has a second opposing end (122) that serves as the end of the first surface. The second opposite end is positioned at a location aligned with the first opposite opening along the axial direction.

[0231] (Technical Concept 11)

[0232] In any of the driving devices described in technical concepts 1 to 10, the heating element has surface-mounted components (175) arranged in a plurality of such components along the inner circumferential surface (913) of the housing in the circumferential direction, and disposed on the inner circumferential surface of the housing. The first peripheral fin extends toward the end of the first surface from a position where it is radially aligned with the surface-mount component. The second peripheral fin extends toward the end of the second surface from a position where it is arranged radially with the surface component.

[0233] (Technical Concept 12)

[0234] In any of the driving devices described in technical concepts 1 to 11, therein is: an electric motor (61) which is supplied with electricity; and

[0235] The inverter section (170) converts the power supplied to the motor. The axial direction is the direction in which the rotation axis (Cm) of the electric motor extends. As the heat-generating part, at least one of the motor and the inverter is housed in the housing.

[0236] (Technical Concept 13)

[0237] In any of the driving devices described in technical concepts 1 to 12, the driving device is a rotary motor disposed on the flying body (10) and used to drive the flying body to fly.

Claims

1. A driving device (50) driven by electricity, comprising: The heating element (170) heats up when energized; A housing (90) having an outer peripheral surface (910) extending axially (AD) and housing the heating element; and The outer peripheral fins (92) extend axially along the outer peripheral surface of the outer shell, and a plurality of them are arranged along the outer peripheral surface of the outer shell in the circumferential direction (CD) of the outer shell, and release the heat of the heating element to the outside of the outer shell. The outer peripheral surface of the outer casing has a first end face (910a) and a second end face (910b), which are a pair of ends arranged along the axial direction. The plurality of said peripheral fins have: The first outer peripheral fin (921, 921A) extends from a position aligned radially (RD) with the heating element along the outer shell towards the first end of the first surface and the second end of the second surface; and The second outer peripheral fin (922, 922A) is disposed at a position separate from the first outer peripheral fin in a direction orthogonal to the radial direction, and extends from a position arranged radially with the heating element to the second end of the first surface end and the second surface end.

2. The driving device according to claim 1, characterized in that, The distance (D1) between two adjacent first outer peripheral fins in the circumferential direction gradually decreases in the axial direction toward the end of the second surface.

3. The driving device according to claim 1, characterized in that, As the first peripheral fin, it includes an expanded fin (921) whose circumferential width (W1) gradually expands toward the end of the second surface.

4. The driving device according to any one of claims 1 to 3, characterized in that, Between two adjacent first outer peripheral fins in the circumferential direction, a first opposing opening (131b) is formed that opens in the axial direction toward the end side of the second surface. Between two adjacent second outer peripheral fins in the circumferential direction, a second opposing opening (132a) is formed that opens in the axial direction toward the end side of the first surface. The first and second opposite ports are arranged along the axial direction.

5. The driving device according to claim 4, characterized in that, It includes a fin clamping portion (202) that extends radially and is at least partially disposed between the first opposing opening and the second opposing opening, and is clamped at at least one of the two first peripheral fins adjacent in the circumferential direction and the two second peripheral fins adjacent in the circumferential direction.

6. The driving device according to claim 5, characterized in that, It includes a pipe section (201), which is disposed on the outer peripheral side of the outer peripheral surface of the outer casing in such a way that it covers the outer peripheral surface of the outer casing from the outer peripheral side, and forms an outer peripheral flow path (130) for gas flow between it and the outer peripheral surface of the outer casing. The fin clamping portion extends radially from the pipe portion toward the outer peripheral surface of the outer shell.

7. The driving device according to claim 5, characterized in that, The fin clamping portion includes a tapered fin (202) whose circumferential width gradually decreases toward the outer circumferential surface of the outer shell.

8. The driving device according to any one of claims 1 to 3, characterized in that, The first outer peripheral fin and the second outer peripheral fin are separated in the axial direction. The first peripheral fin has a first opposing end (113) that serves as the end of the second surface. The second peripheral fin has a second opposing end (122) that serves as the end of the first surface. The first and second opposite ends are offset in the circumferential direction.

9. The driving device according to any one of claims 1 to 3, characterized in that, The first outer peripheral fin and the second outer peripheral fin are separated in the axial direction. The first peripheral fin has a first opposing end (113) that serves as the end of the second surface. The second peripheral fin has a second opposing end (122) that serves as the end of the first surface. The first and second opposite ends are arranged along the axial direction. In the circumferential direction, the width dimension (D2a) of the second opposite end is smaller than the width dimension (D1b) of the first opposite end.

10. The driving device according to any one of claims 1 to 3, characterized in that, The first outer peripheral fin and the second outer peripheral fin are separated in the axial direction. Between two adjacent first outer peripheral fins in the circumferential direction, a first opposing opening (131b) is formed that opens in the axial direction toward the end side of the second surface. The second peripheral fin has a second opposing end (122) that serves as the end of the first surface. The second opposite end is positioned at a location aligned with the first opposite opening along the axial direction.

11. The driving device according to any one of claims 1 to 3, characterized in that, The heating element has surface-mounted components (175) arranged in a plurality of such components along the inner circumferential surface (913) of the outer casing in the circumferential direction, and disposed on the inner circumferential surface of the outer casing. The first peripheral fin extends toward the end of the first surface from a position where it is radially aligned with the surface-mount component. The second peripheral fin extends toward the end of the second surface from a position where it is arranged radially with the surface component.

12. The driving device according to any one of claims 1 to 3, characterized in that, include: Electric motor (61), which is supplied with electricity; and The inverter section (170) converts the power supplied to the motor. The axial direction is the direction in which the rotation axis (Cm) of the electric motor extends. As the heat-generating part, at least one of the motor and the inverter is housed in the housing.

13. The driving device according to any one of claims 1 to 3, characterized in that, The driving device is a rotary motor installed on the flying body (10) and used to drive the flying body to fly.

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