Electrically driven driving device

Abstract

To improve a cooling performance to a rotary electric machine by suppressing the formation of a vortex flow of a cooling air and smoothing the flow of the cooling air.SOLUTION: An electric drive device 251 includes a rotary electric machine 31, and the rotary electric machine 31 includes: a shaft extending in a predetermined axial direction; and a housing 36 extending in an axial direction on the outer circumference of the shaft. On the outer peripheral surface of the housing 36, a plurality of cooling fins 256 to 258 are provided at intervals in a circumferential direction of the housing 36, and a fastening projection 255 for fastening members 37 and 74 adjacent to the housing 36 is provided between the adjacent cooling fins 256 to 258. The fastening projection 255 continuously extends from one end part to the other end part in the axial direction of the housing 36.SELECTED DRAWING: Figure 15

Description

Technical Field

[0001] The present invention relates to an electric drive device.

Background Art

[0002] In recent years, efforts to achieve a low-carbon society or a decarbonized society have been active, and research and development on electrification technologies have been conducted in vehicles, aircraft, etc. in order to reduce CO2 emissions and improve energy efficiency.

[0003] For example, Patent Document 1 discloses a drive device including a rotating electric machine (motor) and a control device (drive unit). As shown in FIG. 5 of Patent Document 1, a plurality of cooling fins protrude from the outer peripheral surface of the housing of the rotating electric machine. Further, a flange for fixing the housing to a fixing target is provided at one end portion in the axial direction of the housing (the upstream end portion in the flow direction of the cooling air).

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] In Patent Document 1, a large gap exists on one side of the flange in the axial direction of the housing (the downstream side of the flange in the flow direction of the cooling air) and between adjacent cooling fins. When a part of the cooling air flowing along the adjacent cooling fins becomes turbulent in the above gap, the flow of the cooling air is inhibited, the wind speed of the cooling air decreases, and there is a risk that the cooling performance for the rotating electric machine deteriorates.

[0006] In view of the above background, an object of the present invention is to improve the cooling performance of a rotating electrical machine by suppressing the swirling of cooling air and smoothing the flow of cooling air in an electric drive device in which a plurality of cooling fins are provided on the outer peripheral surface of a housing of the rotating electrical machine. And, by extension, it contributes to the improvement of energy efficiency.

Means for Solving the Problems

[0007] In order to solve the above problems, an aspect of the present invention is an electric drive device (16, 251) including a rotating electrical machine (31), wherein the rotating electrical machine has a shaft (38) extending in a predetermined axial direction and a housing (36) extending in the axial direction on the outer periphery of the shaft. A plurality of cooling fins (42, 256 to 258) are provided on the outer peripheral surface of the housing at intervals in the circumferential direction of the housing, and fastening protrusions (43, 255) for fastening members (37, 74) adjacent to the housing are provided between the adjacent cooling fins, and the fastening protrusions continuously extend from one end portion to the other end portion of the housing in the axial direction.

[0008] According to this aspect, a flow path for cooling air that is continuous from one end portion to the other end portion of the housing in the axial direction is formed between the plurality of cooling fins and the fastening protrusions. Thereby, swirling of the cooling air in the peripheral region of the fastening protrusion can be suppressed, and the flow of the cooling air can be smoothed. Therefore, a decrease in the wind speed of the cooling air can be suppressed, and the cooling performance for the rotating electrical machine can be improved.

[0009] In the above aspect, a fan (33) is further provided on one side in the axial direction of the rotating electrical machine and sends cooling air toward the outer peripheral surface of the housing by rotating integrally with the shaft. The blowing direction of the fan is inclined with respect to the axial direction, and the fastening protrusion (255) may be inclined with respect to the axial direction along the blowing direction of the fan.

[0010] According to this aspect, the cooling air from the fan can be introduced along the flow thereof into the flow path of the cooling air formed between the plurality of cooling fins and the fastening protrusions. Therefore, it is possible to suppress the flow of the cooling air from being obstructed by the fastening protrusions, and further improve the cooling performance for the rotating electric machine.

[0011] In the above aspect, the fan has a cylindrical rim portion (224) extending in the axial direction, and a plurality of air blowing ribs (226) are provided on the outer peripheral surface of the rim portion. Each of the air blowing ribs may be inclined toward the one side in the axial direction toward the downstream side in the rotation direction of the fan.

[0012] According to this aspect, the cooling air can be sent toward the outer peripheral surface of the housing with a simple configuration.

[0013] In the above aspect, the plurality of cooling fins extend along the axial direction, and one end portion of the plurality of cooling fins in the axial direction faces the side surface of the fastening protrusion with a gap therebetween, and may be aligned along the extending direction of the fastening protrusion.

[0014] According to this aspect, the cooling air that has passed through the flow path between the plurality of cooling fins flows toward the side surface of the fastening protrusion. Therefore, the amount of the cooling air hitting the side surface of the fastening protrusion can be increased, and the heat trapped in the fastening protrusion can be actively discharged.

[0015] In the above aspect, the plurality of cooling fins extend along the axial direction, and one end portion of the plurality of cooling fins in the axial direction faces the side surface of the fastening protrusion with a gap therebetween, and the facing gap between the one end portion of the plurality of cooling fins in the axial direction and the side surface of the fastening protrusion may become wider toward the downstream side in the air blowing direction of the fan.

[0016] According to this aspect, the cooling air that has passed through the flow path between the plurality of cooling fins flows toward the side surface of the fastening projection. Therefore, the amount of cooling air hitting the side surface of the fastening projection can be increased, and the heat trapped in the fastening projection can be actively discharged. Further, by widening the facing interval between one end portion in the axial direction of the plurality of cooling fins and the side surface of the fastening projection as going toward the downstream side, the cooling air hitting the side surface of the fastening projection can be smoothly discharged to the downstream side of the rotating electric machine.

[0017] In the above aspect, the angle formed between the axial direction and the extending direction of the fastening projection may be 45 degrees or less.

[0018] According to this aspect, it is possible to suppress the fastening projection from being excessively inclined with respect to the axial direction. Therefore, it is possible to suppress the flow of the cooling air from being obstructed by the fastening projection, and the cooling performance for the rotating electric machine can be further improved.

[0019] In the above aspect, the angle formed between the axial direction and the extending direction of the fastening projection may be 30 degrees.

[0020] According to this aspect, the fastening projection can be moderately inclined with respect to the axial direction. Therefore, while suppressing the flow of the cooling air from being obstructed by the fastening projection, it is possible to ensure the air volume of the cooling air that passes through the flow path between the plurality of cooling fins and hits the side surface of the fastening projection.

[0021] In the above aspect, the plurality of cooling fins (42) and the fastening projection (43) may extend along the axial direction.

[0022] According to this aspect, by extending the plurality of cooling fins and the fastening projection in the same direction, the flow of the cooling air can be smoothed. Therefore, the cooling performance for the rotating electric machine can be further improved.

[0023] In the above aspect, the fastening projection may be integrally formed of the same material from one end portion to the other end portion in the axial direction.

[0024] According to this aspect, compared with the case where the fastening protrusion is constituted by a plurality of separately formed parts, the constitution of the fastening protrusion can be simplified.

Effect of the Invention

[0025] According to the above aspect, in an electric drive device in which a plurality of cooling fins are provided on the outer peripheral surface of the housing of a rotating electric machine, by suppressing the swirling of the cooling air and smoothing the flow of the cooling air, the cooling performance for the rotating electric machine can be improved.

Brief Description of the Drawings

[0026]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Figure 12

Figure 13

Figure 14

Figure 15

Figure 16

Figure 17

Figure 18

Mode for Carrying Out the Invention

[0027] (First Embodiment) <Aircraft 1> Hereinafter, with reference to FIGS. 1 to 13, an aircraft 1 (an example of a moving body) according to a first embodiment of the present invention will be described.

[0028] Referring to FIG. 1, the aircraft 1 is an electric vertical take-off and landing aircraft (eVTOL) capable of taking off and landing vertically. The aircraft 1 includes a fuselage 2 extending in the front-rear direction, a front wing 3 extending in the left-right direction and connected to the front portion of the fuselage 2, a rear wing 4 extending in the left-right direction and connected to the rear portion of the fuselage 2, a left arm 5L extending in the front-rear direction and connecting the left end portion of the front wing 3 and the left side portion of the rear wing 4, and a right arm 5R extending in the front-rear direction and connecting the right end portion of the front wing 3 and the right side portion of the rear wing 4.

[0029] A cabin (not shown) for passengers to board is provided at the front portion of the fuselage 2. At the rear end portion of the fuselage 2, left and right propulsion units 7 (details will be described later) for generating a forward propulsion force for the aircraft 1 are provided.

[0030] On the left arm 5L and the right arm 5R, a plurality (for example, four) of lifting units 10 for generating lift and downforce on the aircraft 1 are provided at intervals in the front-rear direction. Each lifting unit 10 includes a lifting drive device 12 and a lifting propeller 13 attached to the lifting drive device 12. The lifting drive device 12 has an electric motor (not shown), and is configured to rotate the lifting propeller 13 by the driving force of the electric motor.

[0031] <Propulsion unit 7> Referring to FIG. 2, each propulsion unit 7 includes a support 15, front and rear propulsion drive devices 16 (an example of an electric drive device) supported by the support 15, a rotating shaft 17 extending in the front-rear direction and rotatably supported by the front and rear propulsion drive devices 16, and a propulsion propeller 18 fixed to the rear portion of the rotating shaft 17.

[0032] The support 15 is fixed to the rear end portion of the fuselage 2 (see FIG. 1). The support 15 includes a cylindrical nacelle 20 extending in the front-rear direction and front and rear mount frames 21 fixed to the inner peripheral surface of the nacelle 20. Each mount frame 21 includes an annular hub 23 provided concentrically with the nacelle 20 and a plurality of spokes 24 extending radially from the outer peripheral surface of the hub 23 and connected to the inner peripheral surface of the nacelle 20.

[0033] The front and rear propulsion drive devices 16 are accommodated in the nacelle 20. The front and rear propulsion drive devices 16 are respectively fixed to the front surfaces of the hubs 23 of the front and rear mount frames 21. Details of each propulsion drive device 16 will be described later.

[0034] The rotating shaft 17 is accommodated in the nacelle 20. The rotating shaft 17 passes through the hubs 23 of each mount frame 21. A conical front cover 26 that expands in diameter rearward is fixed to the front end portion of the rotating shaft 17. The front cover 26 is disposed in front of the front propulsion drive device 16. A conical rear cover 27 that expands in diameter forward is fixed to the rear end portion of the rotating shaft 17. The rear cover 27 is disposed behind the central portion of the propulsion propeller 18.

[0035] The propulsion propeller 18 is housed in the nacelle 20. The propulsion propeller 18 is configured to generate a forward propulsion force for the aircraft 1 by rotating integrally with the rotation axis 17 as the rotation axis 17 rotates.

[0036] <Propulsion drive device 16> Referring to FIGS. 2 and 3, each propulsion drive device 16 includes an electric motor 31 (an example of a rotating electrical machine), a control device 32 disposed on the rear side of the electric motor 31, a fan 33 disposed on the front side of the electric motor 31, and a duct cover 34 that covers the outer peripheries of the electric motor 31, the control device 32, and the fan 33. Note that in FIG. 4, the duct cover 34 is not shown.

[0037] <Electric motor 31> Referring to FIGS. 4 and 5, the electric motor 31 is sandwiched between the control device 32 and the fan 33. For example, the electric motor 31 is an inner rotor type three-phase AC motor. The electric motor 31 has a housing 36, a lid body 37, a shaft 38, a rotor 39, and a stator 40.

[0038] The housing 36 is cylindrical and extends in the front-rear direction on the outer periphery of the shaft 38. The housing 36 is disposed on the outer peripheries of the rotor 39 and the stator 40 and houses the rotor 39 and the stator 40 (an example of components of the electric motor 31).

[0039] On the outer peripheral surface of the housing 36, a plurality of first cooling fins 42 project at intervals in the circumferential direction of the housing 36. The plurality of first cooling fins 42 are formed integrally with the housing 36. Each first cooling fin 42 is flat and extends along the front-rear direction. Each first cooling fin 42 extends continuously from the front end portion (one end portion in the front-rear direction) to the rear end portion (the other end portion in the front-rear direction) of the housing 36.

[0040] On the outer peripheral surface of the housing 36, a plurality of fastening protrusions 43 protrude at intervals in the circumferential direction of the housing 36. The plurality of fastening protrusions 43 are provided between adjacent first cooling fins 42. A cooling air flow path P that extends continuously from the front end portion to the rear end portion of the housing 36 is formed between each adjacent first cooling fin 42 and each fastening protrusion 43. The plurality of fastening protrusions 43 are integrally formed with the housing 36.

[0041] Each fastening protrusion 43 has a rod shape with a rectangular cross section and extends along the front-rear direction. That is, each fastening protrusion 43 extends in parallel with each first cooling fin 42. Each fastening protrusion 43 extends continuously from the front end portion (one end portion in the front-rear direction) to the rear end portion (the other end portion in the front-rear direction) of the housing 36. Each fastening protrusion 43 is integrally formed of the same material from the front end portion (one end portion in the front-rear direction) to the rear end portion (the other end portion in the front-rear direction).

[0042] At the front end portion of each fastening protrusion 43, a first bolt hole 44 for fastening the lid body 37 to the housing 36 is provided. At the rear end portion of each fastening protrusion 43, a second bolt hole 45 for fastening the casing 74 of the control device 32, which will be described later, to the housing 36 is provided. The first bolt hole 44 and the second bolt hole 45 extend along the front-rear direction.

[0043] The lid body 37 is adjacent to the housing 36 and closes the opening on the front side (opposite side to the control device 32) of the housing 36. The lid body 37 has a disk shape and extends along a plane orthogonal to the front-rear direction. The lid body 37 is formed separately from the housing 36. In other embodiments, the lid body 37 may be integrally formed with the housing 36.

[0044] On the outer peripheral portion of the lid body 37, a plurality of first fastening pieces 47 project at intervals in the circumferential direction of the lid body 37. Each first fastening piece 47 is provided with a first fastening hole 48 in the front-rear direction, and the lid body 37 is fastened to the housing 36 by engaging a first fastening bolt 49 passing through the first fastening hole 48 with the first bolt hole 44 of each fastening projection 43 of the housing 36. A circular first through hole 51 is provided in the central portion of the lid body 37 in the front-rear direction. A first bearing 52 is attached to the first through hole 51.

[0045] Referring to FIG. 2, the shaft 38 extends in the front-rear direction (an example of a predetermined axial direction). The shaft 38 forms a part of the rotating shaft 17 of the propulsion unit 7. Therefore, when the shaft 38 rotates, the entire rotating shaft 17 rotates, and the propulsion propeller 18 rotates integrally with the rotating shaft 17. As a result, a forward propulsion force is generated on the aircraft 1, and the aircraft 1 propels forward. The shaft 38 extends along the propulsion direction of the aircraft 1 (see the arrow X in FIG. 2).

[0046] Referring to FIG. 5, the shaft 38 is hollow. The shaft 38 has a main body portion 55 housed in the housing 36, an extension portion 56 extending rearward (toward the control device 32 side) from the main body portion 55, and a protruding portion 57 protruding forward (opposite to the control device 32 side) from the main body portion 55. The protruding portion 57 passes through the first through hole 51 of the lid body 37 and extends to the space on the front side of the electric motor 31. The protruding portion 57 is rotatably supported by the lid body 37 via the first bearing 52.

[0047] Referring to FIGS. 4 and 5, the rotor 39 is hollow. The rotor 39 is disposed on the outer periphery of the main body portion 55 of the shaft 38. The rotor 39 has a cylindrical rotor core 61 extending in the front-rear direction, a rotor plate 62 extending in the radial direction and connecting the main body portion 55 of the shaft 38 and the rotor core 61, and a plurality of permanent magnets 63 fixed to the outer peripheral surface of the rotor core 61. The rotor core 61 and the rotor plate 62 are integrally formed with the shaft 38. The rotor plate 62 is provided with a plurality of communication holes 65 penetrating in the front-rear direction.

[0048] The stator 40 is disposed on the outer periphery of the rotor 39 and faces the rotor 39 with a gap therebetween. The stator 40 includes a cylindrical stator core 67 extending in the front-rear direction, a plurality of teeth 68 protruding from the inner peripheral surface of the stator core 67, a plurality of coils 69 wound around the plurality of teeth 68, and three motor-side terminals 70 (an example of terminals on the rotating electrical machine side) connected to the plurality of coils 69. The stator core 67 is fixed to the inner peripheral surface of the housing 36. Among the components of the electric motor 31 and the control device 32, the plurality of coils 69 generate the largest amount of heat. Therefore, the amount of heat generated by the electric motor 31 is larger than that generated by the control device 32. The three motor-side terminals 70 respectively correspond to the U-phase, V-phase, and W-phase of a three-phase alternating current.

[0049] <Control device 32> Referring to FIGS. 3 and 4, the control device 32 is integrated with the electric motor 31 and controls the drive of the electric motor 31. That is, the propulsion drive device 16 of the present embodiment is an electromechanical integrated drive device.

[0050] Referring to FIGS. 6 and 7, the control device 32 includes a casing 74, a resolver 75, a DC input connector 76, three power modules 77, three pressing members 78, a smoothing capacitor 79, three first connection members 80, three second connection members 81, first and second DC bus bars 82 and 83, three AC bus bars 84, three current sensors 85, a communication connector 86, a drive board 87, a control board 88, and a partitioning member 89 (see FIG. 5). Note that in FIG. 5, the electronic components E of the control device 32 (for example, the three power modules 77, the smoothing capacitor 79, the three current sensors 85, the drive board 87, and the control board 88) are omitted, and only the approximate positions of the electronic components E are shown.

[0051] Referring to FIG. 5, the casing 74 is adjacent to the housing 36 of the electric motor 31. The casing 74 is formed of metal and has a bottomed cylindrical shape. The casing 74 houses the electronic components E of the control device 32.

[0052] The casing 74 has a cylindrical peripheral wall portion 93 extending in the front-rear direction on the outer periphery of the extension portion 56 of the shaft 38, and a bottom wall portion 94 closing the opening on the rear side (the side opposite to the electric motor 31) of the peripheral wall portion 93. Hereinafter, when describing the components of the control device 32, the "circumferential direction" refers to the circumferential direction of the peripheral wall portion 93 of the casing 74 (in other words, the circumferential direction centered on the extension portion 56 of the shaft 38), and when describing the components of the control device 32, the "radial direction" refers to the radial direction of the peripheral wall portion 93 of the casing 74 (in other words, the radial direction centered on the extension portion 56 of the shaft 38).

[0053] Referring to FIGS. 3 and 4, a plurality of second cooling fins 96 project from the outer peripheral surface of the peripheral wall portion 93 of the casing 74 at intervals in the circumferential direction. The plurality of second cooling fins 96 are integrally formed with the peripheral wall portion 93. Each second cooling fin 96 has a flat plate shape and extends along the front-rear direction. Each second cooling fin 96 continuously extends from the front end portion (one end portion in the front-rear direction) to the rear end portion (the other end portion in the front-rear direction) of the peripheral wall portion 93.

[0054] Referring to FIGS. 3 and 5, a plurality of second fastening pieces 97 project from the front end portion (the end portion on the electric motor 31 side) of the outer peripheral surface of the peripheral wall portion 93 of the casing 74 at intervals in the circumferential direction. Each second fastening piece 97 is provided with a second fastening hole 98 in the front-rear direction, and the casing 74 is fastened to the housing 36 by engaging a second fastening bolt 99 passing through the second fastening hole 98 with the second bolt hole 45 of each fastening projection 43 of the housing 36.

[0055] A plurality of third fastening pieces 101 project from the rear end portion (the end portion on the side opposite to the electric motor 31) of the outer peripheral surface of the peripheral wall portion 93 of the casing 74 at intervals in the circumferential direction. Each third fastening piece 101 is provided with a third fastening hole 102 in the front-rear direction.

[0056] Referring to FIGS. 7 and 8, on the inner peripheral surface of the peripheral wall portion 93 of the casing 74, three pedestal portions 105 project at intervals in the circumferential direction. On both circumferential sides of the inner surface (radially inner surface) of each pedestal portion 105, a pair of fixing protrusions 106 project. At the central portion in the circumferential direction of the inner surface of each pedestal portion 105, an engagement recess 107 is provided between the pair of fixing protrusions 106. Two of the three pedestal portions 105 are arranged such that the circumferential position of one fixing protrusion 106 overlaps with the circumferential position of a plurality of second fastening pieces 97, and the other fixing protrusion 106 is arranged such that its circumferential position does not overlap with the circumferential positions of the plurality of second fastening pieces 97.

[0057] Referring to FIGS. 5 and 6, the bottom wall portion 94 of the casing 74 is in the shape of a disc and extends along a plane orthogonal to the front-rear direction. The bottom wall portion 94 is formed separately from the peripheral wall portion 93. In other embodiments, the bottom wall portion 94 may be integrally formed with the peripheral wall portion 93.

[0058] On the outer peripheral portion of the bottom wall portion 94 of the casing 74, a plurality of fourth fastening pieces 109 project at intervals in the circumferential direction. Each fourth fastening piece 109 is provided with a fourth fastening hole 110 in the front-rear direction, and the bottom wall portion 94 is fastened to the peripheral wall portion 93 by engaging a third fastening bolt 111 passing through the fourth fastening hole 110 with the third fastening hole 102 of each third fastening piece 101 of the peripheral wall portion 93.

[0059] At the central portion of the bottom wall portion 94 of the casing 74, a circular second through hole 113 is provided in the front-rear direction. A second bearing 114 is attached to the second through hole 113. The extension portion 56 of the shaft 38 passes through the second through hole 113. The extension portion 56 of the shaft 38 is rotatably supported by the second through hole 113 via the second bearing 114. At the lower portion of the bottom wall portion 94, a first fitting hole 116 and a second fitting hole 117 are provided in the front-rear direction at intervals in the circumferential direction.

[0060] Referring to FIG. 6, the resolver 75 is fixed to the central portion of the bottom wall portion 94 of the casing 74. A plurality of detection portions (not shown) for detecting the rotation of the extension portion 56 of the shaft 38 are provided at intervals in the circumferential direction on the resolver 75.

[0061] Referring to FIG. 9, the DC input connector 76 is connected to a DC power supply device 125 provided outside the propulsion drive device 16. For example, the DC power supply device 125 is constituted by a battery or a generator.

[0062] Referring to FIGS. 3 and 6, the DC input connector 76 is fitted into the first fitting hole 116 of the bottom wall portion 94 of the casing 74 and penetrates the bottom wall portion 94 of the casing 74. A pair of DC input terminals 126 are provided on the front surface (the surface on the side of the electric motor 31) of the DC input connector 76.

[0063] Referring to FIG. 9, the three power modules 77 each include two switching elements 128. That is, the control device 32 includes a total of six switching elements 128. The six switching elements 128 constitute an inverter 130 (an example of a power conversion circuit) that converts DC power (DC current) input from the DC power supply device 125 via a pair of DC lines 129 into AC power (AC current). Each switching element 128 is constituted by a semiconductor element such as an IGBT or a MOSFET. Each switching element 128 is arranged in parallel with a freewheel diode 131.

[0064] Referring to FIGS. 7 and 8, the three power modules 77 are in contact with the inner peripheral surface of the peripheral wall portion 93 of the casing 74 at circumferential intervals. The circumferential positions of the three power modules 77 do not overlap with the circumferential positions of the plurality of second fastening pieces 97 (i.e., the fastening points between the casing 74 and the housing 36), and overlap with the circumferential positions of the plurality of second cooling fins 96. The three power modules 77 are arranged avoiding the uppermost part of the casing 74. Note that the arrow D1 appropriately attached to each figure indicates the direction parallel to the inner surface 77A of each power module 77 (hereinafter referred to as the "first direction D1"). Also, the arrow D2 appropriately attached to each figure indicates the direction orthogonal to the first direction D1 and the inner surface 77A of the power module 77 (hereinafter referred to as the "second direction D2").

[0065] Each power module 77 includes a flat module body 133, an AC module bus bar 134 extending radially inward from the front end portion (one end portion in the front-rear direction) of the module body 133, and a first DC module bus bar 135 and a second DC module bus bar 136 extending radially inward from the rear end portion (the other end portion in the front-rear direction) of the module body 133.

[0066] The three pressing members 78 are arranged at circumferential intervals. Each pressing member 78 includes a rectangular parallelepiped engaging piece 138 and a plurality of protruding pieces 139 protruding from both circumferential sides of the engaging piece 138. The engaging piece 138 is engaged with the engaging recess 107 of each pedestal portion 105 provided on the inner peripheral surface of the peripheral wall portion 93 of the casing 74. The engaging piece 138 sandwiches the module body 133 of each power module 77 between it and the engaging recess 107 of each pedestal portion 105, and presses the module body 133 of each power module 77 against the engaging recess 107 of each pedestal portion 105. An AC insert nut 142 is embedded in the front surface (one side surface in the front-rear direction) of the engaging piece 138, and two DC insert nuts 143 are embedded in the rear surface (the other side surface in the front-rear direction) of the engaging piece 138. Each protruding piece 139 is fixed to each fixing protrusion 106 of each pedestal portion 105 by a fixing bolt 144.

[0067] Referring to FIG. 9, the smoothing capacitor 79 is connected in parallel with the inverter 130 to the DC power supply device 125. The smoothing capacitor 79 smoothes the DC current input from the DC power supply device 125 to the inverter 130. More specifically, the smoothing capacitor 79 protects the three power modules 77 by smoothing the pulsed current (pulse-shaped current caused by the surge voltage) generated in the DC current input from the DC power supply device 125 to the three power modules 77.

[0068] Referring to FIG. 7, the smoothing capacitor 79 is provided at a distance from the inner peripheral surface of the peripheral wall portion 93 of the casing 74. The smoothing capacitor 79, together with the three power modules 77, is arranged in the left semicircular portion (an example of one semicircular portion) of the casing 74. The smoothing capacitor 79 is continuously provided along the inner surface 77A of the three power modules 77 (more specifically, the radially inner surface of the module body 133 of the three power modules 77). Therefore, when viewed from the front side (the side of the electric motor 31), between the second through hole 113 in the bottom wall portion 94 of the casing 74 and the inner peripheral surface of the peripheral wall portion 93 of the casing 74, the smoothing capacitor 79 and each power module 77 are arranged in order from the radially inner side to the outer side.

[0069] Referring to FIG. 10, the smoothing capacitor 79 is arranged at a radial distance from each power module 77. The smoothing capacitor 79 and each power module 77 are arranged on the same plane orthogonal to the front-rear direction. In other words, the front-rear position of the smoothing capacitor 79 overlaps with the front-rear position of each power module 77.

[0070] Referring to FIGS. 7 and 11, the smoothing capacitor 79 includes a plurality of capacitor elements 147 and a capacitor case 148 that houses the plurality of capacitor elements 147. That is, the smoothing capacitor 79 is configured as a capacitor unit in which a plurality of capacitor elements 147 are integrated. The smoothing capacitor 79 is bent so as to protrude toward each power module 77 side (radially outward) when viewed from the front side (the side of the electric motor 31), and forms a substantially U shape.

[0071] The capacitor case 148 is filled with a potting agent (not shown). For example, the potting agent is made of an insulating resin. The capacitor case 148 includes a case body 153 and three closing members 154 attached to the case body 153.

[0072] The case body 153 of the capacitor case 148 is made of a metal such as aluminum. The case body 153 has a box shape with an open front surface (a surface on one side in the front-rear direction). A plurality of support protrusions 156 are provided at the front end portion (one end portion in the front-rear direction) of the case body 153. A plurality of mounting protrusions 157 are provided at the rear end portion (the other end portion in the front-rear direction) of the case body 153. Each mounting protrusion 157 is attached to the bottom wall portion 94 of the casing 74 by a mounting bolt 158.

[0073] The case body 153 of the capacitor case 148 includes an inner wall portion 160 (a radially inner wall portion) extending in the circumferential direction, an outer wall portion 161 (a radially outer wall portion) extending in the circumferential direction on the radially outer side of the inner wall portion 160, a pair of side wall portions 162 extending in the radial direction and connecting both circumferential ends of the inner wall portion 160 and both circumferential ends of the outer wall portion 161, and a base wall portion 163 connecting the rear ends (ends opposite to the electric motor 31) of the inner wall portion 160, the outer wall portion 161, and the pair of side wall portions 162. Three planar portions 165 are formed inside the capacitor elements 147 in the radial direction on the inner wall portion 160. When viewed from the front side (the side of the electric motor 31), each planar portion 165 extends along the second direction D2. Three case openings 166 are formed outside the capacitor elements 147 in the radial direction on the outer wall portion 161. The three case openings 166 are arranged at intervals in the circumferential direction. Each case opening 166 has a rectangular shape that is long in the front-rear direction and the first direction D1. Three fitting recesses 167 (see FIG. 10) are formed at positions on the radially outer portion of the base wall portion 163 facing the three case openings 166.

[0074] Referring to FIGS. 7 and 10, the three closing members 154 of the capacitor case 148 close the three case openings 166 of the case body 153, respectively. Each closing member 154 is made of an insulating resin. Each closing member 154 includes a first closing piece 169 and a second closing piece 170 arranged on the front side (one side in the front-rear direction) of the first closing piece 169.

[0075] Referring to FIGS. 10 and 12, the first closing piece 169 of each closing member 154 is fitted into each fitting recess 167 of the case body 153. On the front surface (one surface in the front-rear direction) of the first closing piece 169, three partition ribs 172 extending in the second direction D2 and a connecting rib 173 extending in the first direction D1 and connecting the middle portions of the three partition ribs 172 are provided. Two mounting grooves 174 extending in the second direction D2 are provided between the three partition ribs 172 and on the rear side (the other side in the front-rear direction) of the connecting rib 173.

[0076] Referring to FIGS. 10 and 11, the second closing piece 170 of each closing member 154 is formed separately from the first closing piece 169. The second closing piece 170 has a flat rectangular parallelepiped shape that is long in the front-rear direction and the first direction D1. On both sides of the second closing piece 170 in the first direction D1, a pair of first engaging grooves 176 extending in the front-rear direction are formed. The pair of first engaging grooves 176 engage with the outer wall portion 161 of the case body 153 on both sides of each case opening 166 in the first direction D1. The front end portion (one end portion in the front-rear direction) of the second closing piece 170 is provided flush with the front surface (one surface in the front-rear direction) of the outer wall portion 161 of the case body 153. A second engaging groove 177 extending in the first direction D1 is formed at the rear end portion (the other end portion in the front-rear direction) of the second closing piece 170. The second engaging groove 177 engages with the connection rib 173 of the first closing piece 169.

[0077] Referring to FIGS. 10 and 13, each first connecting member 80 connects each capacitor element 147 and each power module 77. The radially inner end portion of each first connecting member 80 is connected to the upper portion of the side surface (the radially outer surface) of each capacitor element 147. Each first connecting member 80 engages with one mounting groove 174 of the first closing piece 169 of each closing member 154. Each first connecting member 80 passes through the rear side of the second closing piece 170 (see FIGS. 10 and 11) of each closing member 154 and extends to the rear side of each power module 77. That is, each first connecting member 80 penetrates each closing member 154.

[0078] Referring to FIGS. 10 and 13, each second connecting member 81 connects each capacitor element 147 and each power module 77. The radially inner end portion of each second connecting member 81 is connected to the lower portion of the side surface (the radially outer surface) of each capacitor element 147. Each second connecting member 81 engages with the other mounting groove 174 of the first closing piece 169 of each closing member 154. Each second connecting member 81 passes through the rear side of the second closing piece 170 (see FIGS. 10 and 11) of each closing member 154 and extends to the rear side of each power module 77. That is, each second connecting member 81 penetrates each closing member 154.

[0079] Referring to FIG. 6, the first DC bus bar 82 has a first main body bus bar 199 extending in the circumferential direction and three first auxiliary bus bars 200 bent rearward from the outer peripheral portion of the first main body bus bar 199. One circumferential end portion of the first main body bus bar 199 is connected to one DC input terminal 126 of the DC input connector 76. Referring to FIG. 13, the tip of each first auxiliary bus bar 200 is bent radially outward and extends to the rear side of each pressing member 78. The tip of each first auxiliary bus bar 200, together with the first DC module bus bar 135 of each power module 77 and the radially outer end portion of each first connecting member 80, is fixed to one DC insert nut 143 of each pressing member 78 by a first fixing bolt 201. Thereby, the first DC bus bar 82, each power module 77, and each first connecting member 80 are connected to each other.

[0080] Referring to FIG. 6, the second DC bus bar 83 has a second main body bus bar 203 extending in the circumferential direction and three second auxiliary bus bars 204 bent rearward from the outer peripheral portion of the second main body bus bar 203. One circumferential end portion of the second main body bus bar 203 is connected to the other DC input terminal 126 of the DC input connector 76. Referring to FIG. 13, the tip of each second auxiliary bus bar 204 is bent radially outward and extends to the rear side of each pressing member 78. The tip of each second auxiliary bus bar 204, together with the second DC module bus bar 136 of each power module 77 and the radially outer end portion of each second connecting member 81, is fixed to the other DC insert nut 143 of each pressing member 78 by a second fixing bolt 205. Thereby, the second DC bus bar 83, each power module 77, and each second connecting member 81 are connected to each other.

[0081] Referring to FIGS. 6 and 13, one longitudinal end of each AC bus bar 84 is fixed to the AC insert nut 142 of each pressing member 78 by a third fixing bolt 209 together with the AC module bus bar 134 of each power module 77. Thus, each AC bus bar 84 and each power module 77 are connected to each other. An AC output terminal 211 is provided at the other longitudinal end of each AC bus bar 84. That is, the control device 32 is provided with three AC output terminals 211. The three AC output terminals 211 are arranged together with a pair of DC input terminals 126 at the right semi-circular part (an example of the other semi-circular part) of the casing 74. The three AC output terminals 211 are arranged at intervals in the circumferential direction from the pair of DC input terminals 126. Each AC output terminal 211 is connected to each motor-side terminal 70 (see FIG. 4) of the stator 40 of the electric motor 31 in the internal space of the casing 74. Thus, as shown in FIG. 9, the alternating current output from the inverter 130 (three power modules 77) is output to each coil 69 of the electric motor 31 via each AC output terminal 211 and each motor-side terminal 70.

[0082] Referring to FIG. 9, the three current sensors 85 are respectively arranged on three AC lines 207 (three-phase lines) from the inverter 130 (three power modules 77) to each coil 69 of the electric motor 31, and detect the values of the currents output from the three power modules 77.

[0083] Referring to FIG. 6, the three current sensors 85 are respectively arranged on the three AC bus bars 84. The three current sensors 85 are arranged at the right semi-circular part of the casing 74. The three current sensors 85 are arranged at intervals in the circumferential direction. The three current sensors 85 are fixed to a sensor holder 214 fixed to the outer periphery of the bottom wall portion 94 of the casing 74. The sensor holder 214 is formed separately from the resolver 75.

[0084] The communication connector 86 is arranged circumferentially between a pair of DC input terminals 126 and three AC output terminals 211. The communication connector 86 is fitted into the second fitting hole 117 of the bottom wall portion 94 of the casing 74 and penetrates the bottom wall portion 94 of the casing 74. The communication connector 86 is connected to an external device (for example, a control device provided in the body 2) provided outside the propulsion drive device 16.

[0085] The drive board 87 is a gate drive board for driving the switching elements 128 (semiconductor elements) of the three power modules 77. The drive board 87 is arranged on the front side (the side of the electric motor 31) of the smoothing capacitor 79. The drive board 87 is supported by a plurality of support protrusions 156 provided on the case body 153 of the capacitor case 148 of the smoothing capacitor 79.

[0086] The control board 88 is an ECU board that controls the drive of the inverter 130 (three power modules 77) via the drive board 87. The control board 88 is connected to the drive board 87 via a connector (not shown) and is also connected to the communication connector 86 via a cable (not shown). The control board 88 is held by a holding member (not shown) attached to the bottom wall portion 94 of the casing 74.

[0087] Referring to FIG. 5, the partitioning member 89 partitions the internal space of the housing 36 and the internal space of the casing 74. The partitioning member 89 partitions the rotor 39 and the stator 40 of the electric motor 31 and the electronic components E of the control device 32 (for example, three power modules 77, a smoothing capacitor 79, three current sensors 85, a drive board 87, and a control board 88). The partitioning member 89 is housed in the casing 74. In other embodiments, the partitioning member 89 may be housed in the housing 36 of the electric motor 31. The partitioning member 89 has a flat plate shape along a plane perpendicular to the front-rear direction. A shaft hole 216 is provided at the center of the partitioning member 89. The extension portion 56 of the shaft 38 penetrates the shaft hole 216.

[0088] <Fan 33> Referring to FIGS. 3 to 5, the fan 33 is disposed on the front side (one side in the front-rear direction) of the electric motor 31. The fan 33 is disposed on the side opposite to the control device 32 with the electric motor 31 interposed therebetween. The fan 33 has a cylindrical hub portion 223 extending in the front-rear direction, a cylindrical rim portion 224 extending in the front-rear direction on the outer periphery of the hub portion 223, and a plurality of spoke portions 225 extending in the radial direction and connecting the hub portion 223 and the rim portion 224. The hub portion 223 is fixed to the protruding portion 57 of the shaft 38 of the electric motor 31. Thereby, the fan 33 can rotate integrally with the shaft 38. A plurality of air blowing ribs 226 are provided on the outer peripheral surface of the rim portion 224 at intervals in the circumferential direction of the rim portion 224. Each air blowing rib 226 is inclined forward (one side in the front-rear direction) toward the downstream side in the rotation direction R of the fan 33.

[0089] <Duct cover 34> Referring to FIGS. 3 and 4, the duct cover 34 has a cylindrical shape extending in the front-rear direction. A cooling air passage 229 is formed between the duct cover 34, the housing 36 of the electric motor 31, and the peripheral wall portion 93 of the casing 74 of the control device 32. That is, the cooling air passage 229 is formed on the outer periphery of the housing 36 of the electric motor 31 and the casing 74 of the control device 32. The cooling air passage 229 has a cylindrical shape and extends in the front-rear direction.

[0090] <Cooling of the electric motor 31 and the control device 32> Referring to FIGS. 3 and 5, when the electric motor 31 is driven and the shaft 38 rotates, the fan 33 fixed to the protruding portion 57 of the shaft 38 rotates integrally with the shaft 38. Thereby, the cooling air is sent toward the outer peripheral surface of the housing 36 and the outer peripheral surface of the peripheral wall portion 93 of the casing 74 by the plurality of air blowing ribs 226 of the fan 33. That is, the cooling air is introduced into the cooling air passage 229 by the plurality of air blowing ribs 226 of the fan 33.

[0091] The cooling air introduced into the cooling air passage 229 flows from the front side to the rear side between the outer periphery of the housing 36 and the plurality of first cooling fins 42. Thereby, the electric motor 31 is cooled by the cooling air. Next, the cooling air flows from the front side to the rear side between the outer periphery of the peripheral wall portion 93 of the casing 74 and the plurality of second cooling fins 96. Thereby, the housing 36 of the control device 32 is cooled by the cooling air. The cooling air that has passed through the outer periphery of the peripheral wall portion 93 of the casing 74 is discharged from the rear end portion of the cooling air passage 229 to the space behind the control device 32.

[0092] <Effect> FIG. 14 is a plan view schematically showing a propulsion drive device 241 according to a comparative example. The broken-line arrow in FIG. 14 indicates the flow of the cooling air in the propulsion drive device 241 according to the comparative example.

[0093] In the propulsion drive device 241 according to the comparative example, flanges 242 and 243 for fixing the housing 36 to the lid body 37 and the peripheral wall portion 93 of the casing 74 are provided at both the front and rear end portions of the outer peripheral surface of the housing 36. There is a large gap between the flange 242 at the front end portion of the housing 36 and the flange 243 at the rear end portion of the housing 36. When a part of the cooling air flowing along the adjacent first cooling fins 42 is vortexed in the above gap, the flow of the cooling air is inhibited, and there is a risk that the cooling performance for the electric motor 31 may deteriorate.

[0094] On the other hand, in the present embodiment, as shown in FIG. 3, the plurality of fastening protrusions 43 continuously extend from the front end portion to the rear end portion of the housing 36. Therefore, a cooling air flow path P that is continuous from the front end portion to the rear end portion of the housing 36 is formed between the adjacent first cooling fins 42 and each fastening protrusion 43. Thereby, the vortex formation of the cooling air in the peripheral region of each fastening protrusion 43 can be suppressed, and the flow of the cooling air can be smoothed. Therefore, a decrease in the wind speed of the cooling air can be suppressed, and the cooling performance for the electric motor 31 can be improved.

[0095] (Second Embodiment) Next, with reference to FIG. 15, a propulsion drive device 251 (an example of an electric drive device) according to the second embodiment of the present invention will be described. The dashed arrows in FIG. 15 indicate the flow of cooling air in the propulsion drive device 251 according to the second embodiment. Note that, except for the plurality of fastening protrusions 255 and the plurality of first cooling fins 256 to 258 provided on the housing 36, since they are the same as those in the first embodiment, the description thereof will be omitted. Hereinafter, after explaining the blowing direction W of the fan 33, which is a premise for explaining the plurality of fastening protrusions 255, the plurality of fastening protrusions 255 and the plurality of first cooling fins 256 to 258 will be described.

[0096] <Blowing direction W of fan 33> As described above, each blowing rib 226 of the fan 33 is inclined forward (one side in the front-rear direction) toward the downstream side in the rotation direction R of the fan 33. Therefore, when the fan 33 rotates, air is generated along a predetermined direction (hereinafter referred to as the "blowing direction W of the fan 33") inclined with respect to the front-rear direction.

[0097] The blowing direction W of the fan 33 is a direction obtained by synthesizing the direction W1 in which the fan 33 attempts to discharge air and the direction W2 of the inertial force generated by the air being pushed against each blowing rib 226. The direction W1 in which the fan 33 attempts to discharge air is parallel to the front-rear direction. The direction W2 of the inertial force generated by the air being pushed against each blowing rib 226 is parallel to the rotation direction R of the fan 33.

[0098] <Plurality of fastening protrusions 255> On the outer peripheral surface of the housing 36, a plurality of fastening protrusions 255 (only one is shown in FIG. 15) protrude at intervals in the circumferential direction of the housing 36. Each fastening protrusion 255 is provided between the adjacent first cooling fins 256 to 258 in the circumferential direction of the housing 36. Between the adjacent first cooling fins 256 to 258 and each fastening protrusion 255, first flow paths P1 and second flow paths P2 of cooling air continuous from the front end portion to the rear end portion of the housing 36 are formed. Each fastening protrusion 255 is integrally formed with the housing 36.

[0099] Each fastening projection 255 has a rod shape with a rectangular cross section and is inclined with respect to the front-rear direction along the air blowing direction W of the fan 33. That is, the air blowing direction W of the fan 33 and the extending direction Y of each fastening projection 255 are parallel. In the present embodiment, the angle θ formed by the front-rear direction and the extending direction Y of each fastening projection 255 is 45 degrees or less. For example, the angle θ formed by the front-rear direction and the extending direction Y of each fastening projection 255 is 30 degrees. In other embodiments, the angle θ formed by the front-rear direction and the extending direction Y of each fastening projection 255 may exceed 45 degrees. Each fastening projection 255 continuously extends from the front end portion (one end portion in the front-rear direction) to the rear end portion (the other end portion in the front-rear direction) of the housing 36. Each fastening projection 255 is integrally formed of the same material from the front end portion (one end portion in the front-rear direction) to the rear end portion (the other end portion in the front-rear direction).

[0100] At the front end portion of each fastening projection 255, a first bolt hole 261 for fastening the lid body 37 to the housing 36 is provided. The first bolt hole 261 is inclined with respect to the front-rear direction and extends along the extending direction Y of each fastening projection 255. Accordingly, the first fastening holes 48 and the first fastening bolts 49 (refer to the first embodiment) of each first fastening piece 47 of the lid body 37 are also inclined with respect to the front-rear direction and extend along the extending direction Y of each fastening projection 255.

[0101] At the rear end portion of each fastening projection 255, a second bolt hole 262 for fastening the peripheral wall portion 93 of the casing 74 of the control device 32 to the housing 36 is provided. The second bolt hole 262 is inclined with respect to the front-rear direction and extends along the extending direction Y of each fastening projection 255. Accordingly, the second fastening holes 98 (refer to the first embodiment) and the second fastening bolts 99 of each second fastening piece 97 of the peripheral wall portion 93 are also inclined with respect to the front-rear direction and extend along the extending direction Y of each fastening projection 255.

[0102] On the outer peripheral surface of the housing 36, a plurality of first cooling fins 256 to 258 protrude at intervals in the circumferential direction of the housing 36. The plurality of first cooling fins 256 to 258 are integrally formed with the housing 36. Each of the first cooling fins 256 to 258 has a flat plate shape and extends along the front-rear direction.

[0103] The plurality of first cooling fins 256 to 258 include a plurality of non-overlapping fins 256, a plurality of first overlapping fins 257, and a plurality of second overlapping fins 258.

[0104] The plurality of non-overlapping fins 256 are arranged so that their positions in the circumferential direction of the housing 36 do not overlap with the respective fastening protrusions 255. The plurality of non-overlapping fins 256 continuously extend from the front end portion (one end portion in the front-rear direction) to the rear end portion (the other end portion in the front-rear direction) of the housing 36.

[0105] The plurality of first overlapping fins 257 are arranged so that their positions in the circumferential direction of the housing 36 overlap with the respective fastening protrusions 255. The plurality of first overlapping fins 257 are arranged on the front side (one side in the front-rear direction) of each fastening protrusion 255. The length of the plurality of first overlapping fins 257 in the front-rear direction is shorter than the length of the plurality of non-overlapping fins 256 in the front-rear direction. The rear end portion (one end portion in the front-rear direction) of the plurality of first overlapping fins 257 faces one side surface (one side surface in the circumferential direction of the housing 36) of each fastening protrusion 255 via the first flow path P1 and is aligned along the extending direction Y of each fastening protrusion 255. Therefore, the opposing interval Z1 between the rear end portion of the plurality of first overlapping fins 257 and one side surface of each fastening protrusion 255 is constant from the upstream side to the downstream side in the blowing direction W of the fan 33.

[0106] The plurality of second overlapping fins 258 are arranged such that their circumferential positions in the housing 36 overlap with the respective fastening protrusions 255. The plurality of second overlapping fins 258 are arranged on the rear side (the other side in the front-rear direction) of each fastening protrusion 255. The length of the plurality of second overlapping fins 258 in the front-rear direction is shorter than the length of the plurality of non-overlapping fins 256 in the front-rear direction. The front end portions (one end portion in the front-rear direction) of the plurality of second overlapping fins 258 face the other side surfaces (the other side surfaces in the circumferential direction of the housing 36) of the respective fastening protrusions 255 via the second flow path P2 and are aligned along the extending direction Y of each fastening protrusion 255. Therefore, the facing interval Z2 between the front end portions of the plurality of second overlapping fins 258 and the other side surfaces of the respective fastening protrusions 255 is constant from the upstream side to the downstream side in the blowing direction W of the fan 33.

[0107] <Flow of cooling air> When the fan 33 rotates, the cooling air is introduced into the cooling air passage 229 by the plurality of blowing ribs 226 of the fan 33. A part of the cooling air introduced into the cooling air passage 229 flows from the front side to the rear side between the plurality of non-overlapping fins 256 and is discharged to the rear side (the control device 32 side) of the housing 36.

[0108] Another part of the cooling air introduced into the cooling air passage 229 flows from the front side to the rear side through the first flow path P1 and is discharged to the rear side of the housing 36. Another part of the cooling air introduced into the cooling air passage 229 flows from the front side to the rear side between the plurality of first overlapping fins 257, merges with the cooling air flowing through the first flow path P1, and is discharged to the rear side of the housing 36.

[0109] Another part of the cooling air introduced into the cooling air passage 229 flows from the front side to the rear side through the second flow path P2 and is discharged to the rear side of the housing 36. A part of the cooling air flowing through the second flow path P2 branches off from the second flow path P2, flows from the front side to the rear side between the plurality of second overlapping fins 258, and is discharged to the rear side of the housing 36.

[0110] <Effect> In this embodiment, each fastening projection 255 is inclined with respect to the front-rear direction along the air blowing direction W of the fan 33. Thereby, the cooling air from the fan 33 can be introduced along the flow thereof into the first flow path P1 and the second flow path P2. Therefore, it is possible to suppress the flow of the cooling air from being obstructed by each fastening projection 255 and further improve the cooling performance for the electric motor 31.

[0111] <Modification example> In the second embodiment described above, the facing interval Z1 between the rear end portions of the plurality of first overlapping fins 257 and one side surface of each fastening projection 255 is constant from the upstream side to the downstream side in the air blowing direction W of the fan 33. As shown in FIG. 16, in the first modification example of the second embodiment, the facing interval Z1 between the rear end portions of the plurality of first overlapping fins 257 and one side surface of each fastening projection 255 becomes wider as it goes toward the downstream side in the air blowing direction W of the fan 33. Thereby, the cooling air hitting one side surface of each fastening projection 255 can be smoothly discharged to the rear side of the housing 36.

[0112] In the second embodiment described above, the first bolt hole 261 and the second bolt hole 262 extend along the extending direction Y of each fastening projection 255. As shown in FIG. 17, in the second modification example of the second embodiment, the first bolt hole 261 and the second bolt hole 262 extend along the front-rear direction. Accordingly, the first fastening holes 48 and the first fastening bolts 49 of each first fastening piece 47 of the lid body 37 also extend along the front-rear direction. Similarly, the second fastening holes 98 and the second fastening bolts 99 of each second fastening piece 97 of the peripheral wall portion 93 also extend along the front-rear direction.

[0113] In the above-described second embodiment, each fastening projection 255 is integrally formed of the same material from the front end portion to the rear end portion. As shown in FIG. 18, in the third modification of the second embodiment, both front and rear end portions 255A (portions where the first bolt hole 261 and the second bolt hole 262 are provided) of each fastening projection 255 and the front and rear central portions 255B of each fastening projection 255 (portions between the portion where the first bolt hole 261 is provided and the portion where the second bolt hole 262 is provided) are formed separately. For example, both front and rear end portions 255A of each fastening projection 255 are formed of metal, and the front and rear central portions 255B of each fastening projection 255 are formed of resin.

[0114] In the above-described first and second embodiments, bolt holes are respectively provided at both front and rear end portions of each fastening projection 43, 255. In other embodiments, bolt holes may be provided only at one end portion of each fastening projection 43, 255.

[0115] In the above-described first and second embodiments, the lid 37 and the peripheral wall portion 93 of the casing 74 are fastened to each fastening projection 43, 255. In other embodiments, members other than the lid 37 and the peripheral wall portion 93 of the casing 74 may be fastened to each fastening projection 43, 255. For example, in other embodiments, a cable may be fastened to each fastening projection 43, 255. That is, in other embodiments, each fastening projection 43, 255 may be a terminal block for fastening a cable.

[0116] In the above-described first and second embodiments, the inner rotor type electric motor 31 is an example of a rotating electric machine. In other embodiments, an outer rotor type electric motor may be an example of a rotating electric machine, or a generator may be an example of a rotating electric machine.

[0117] In the above-described first and second embodiments, the configuration of the present invention is applied to the propulsion drive devices 16, 251. In other embodiments, the configuration of the present invention may be applied to the lifting drive device 12.

[0118] In the above-described first and second embodiments, the configuration of the present invention is applied to an electric vertical takeoff and landing aircraft. In other embodiments, the configuration of the present invention may be applied to an aircraft other than an electric vertical takeoff and landing aircraft (i.e., a general aircraft that cannot take off and land vertically), or the configuration of the present invention may be applied to a moving body other than an aircraft (e.g., vehicles such as automobiles and motorcycles). Further, in other embodiments, the configuration of the present invention may be applied to a fixedly provided device.

[0119] With the above, the description of the specific embodiments is completed. However, the present invention is not limited to the above embodiments and modification examples, and can be widely modified and implemented.

Explanation of Reference Numerals

[0120] 16: Propulsion drive device (an example of an electric drive device) 31: Electric motor (an example of a rotating electric machine) 33: Fan 36: Housing 37: Cover body (an example of a member adjacent to the housing) 38: Shaft 42: First cooling fin 43: Fastening projection 74: Casing (an example of a member adjacent to the housing) 224: Rim portion 226: Air blowing rib 251: Propulsion drive device (an example of an electric drive device) 255: Fastening projection 256~258: First cooling fin R: Rotation direction W: Air blowing direction Y: Extending direction

Claims

1. An electric drive device including a rotating electric machine, wherein the rotating electric machine has a shaft extending in a predetermined axial direction, and a housing extending in the axial direction on the outer periphery of the shaft, wherein a plurality of cooling fins are provided on the outer peripheral surface of the housing at intervals in the circumferential direction of the housing, and fastening protrusions for fastening a member adjacent to the housing are provided between the adjacent cooling fins, and the fastening protrusions continuously extend from one end portion in the axial direction of the housing to the other end portion. The electric drive device.

2. further includes a fan disposed on one side in the axial direction of the rotating electric machine and sending cooling air toward the outer peripheral surface of the housing by rotating integrally with the shaft, wherein the blowing direction of the fan is inclined with respect to the axial direction, and the fastening protrusions are inclined with respect to the axial direction along the blowing direction of the fan. The electric drive device according to claim 1.

3. wherein the fan has a cylindrical rim portion extending in the axial direction, and a plurality of blowing ribs are provided on the outer peripheral surface of the rim portion, and each of the blowing ribs is inclined toward one side in the axial direction toward the downstream side in the rotation direction of the fan. The electric drive device according to claim 2.

4. wherein the plurality of cooling fins extend along the axial direction, and one end portion in the axial direction of the plurality of cooling fins faces the side surface of the fastening protrusion with an interval therebetween and is aligned along the extending direction of the fastening protrusion. The electric drive device according to claim 2 or 3.

5. wherein the plurality of cooling fins extend along the axial direction, and one end portion in the axial direction of the plurality of cooling fins faces the side surface of the fastening protrusion with an interval therebetween, and the facing interval between the one end portion in the axial direction of the plurality of cooling fins and the side surface of the fastening protrusion becomes wider toward the downstream side in the blowing direction of the fan. The electric drive device according to claim 2 or 3.

6. wherein an angle formed by the axial direction and the extending direction of the fastening protrusion is 45 degrees or less. The electric drive device according to claim 2 or 3.

7. wherein an angle formed by the axial direction and the extending direction of the fastening protrusion is 30 degrees. The electric drive device according to claim 6.

8. wherein the plurality of cooling fins and the fastening protrusions extend along the axial direction. The electric drive device according to claim 1.

9. The electric drive device according to claim 1, 2, or 8, wherein the fastening protrusion is integrally formed of the same material from one end portion to the other end portion in the axial direction.

Images