Control device for rotary electric machine

Abstract

To improve space efficiency within a control device by devising the arrangement of a plurality of power modules and a smoothing capacitor.SOLUTION: A control device is integrated with a rotary electric machine and controls driving of the rotary electric machine. The control device comprises: a plurality of power modules 77, each including a switching element constituting a power conversion circuit; a smoothing capacitor 79 for smoothing current input to the plurality of power modules 77; and a cylindrical casing 74 accommodating the plurality of power modules 77 and the smoothing capacitor 79. The plurality of power modules 77 are in contact with an inner circumferential surface of the casing 74 with spacing in a circumferential direction of the casing 74. The smoothing capacitor 79 is provided continuously along inner surfaces 77A of the plurality of power modules 77.SELECTED DRAWING: Figure 7

Description

Technical Field

[0001] The present invention relates to a control device for a rotating electrical machine.

Background Art

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

[0003] For example, Patent Document 1 discloses an advanced electric propulsion system including a rotating electrical machine (electric motor) and a control device coupled to the rotating electrical machine. As shown in FIGS. 2A and 2B of Patent Document 1, a plurality of power modules are coupled to the inner peripheral surface of the control device. The plurality of power modules are provided with switching elements for converting a DC current supplied from a DC power supply device into an AC current.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] By the way, such a control device is provided with a smoothing capacitor for smoothing the DC current supplied from the DC power supply device and protecting a plurality of power modules. This smoothing capacitor is increasing in capacitance as the voltage of the DC power supply device increases and tends to become larger. Therefore, in order to accommodate a plurality of power modules and the smoothing capacitor in the control device, it is required to devise the arrangement of the plurality of power modules and the smoothing capacitor to improve the space efficiency in the control device.

[0006] In view of the above background, an object of the present invention is to improve the space efficiency in a control device integrated with a rotating electrical machine such as an electric motor by devising the arrangement of a plurality of power modules and smoothing capacitors, and by extension, to contribute 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 a control device (32) integrated with a rotating electrical machine (31) and controlling the drive of the rotating electrical machine, the control device including a plurality of power modules (77) each including a switching element (128) constituting a power conversion circuit (130), a smoothing capacitor (79) for smoothing the current input to the plurality of power modules, and a cylindrical casing (74) housing the plurality of power modules and the smoothing capacitor, wherein the plurality of power modules are in contact with the inner peripheral surface of the casing at intervals in the circumferential direction of the casing, and the smoothing capacitor is continuously provided along the inner surface of the plurality of power modules.

[0008] According to this aspect, by bringing the plurality of power modules into contact with the inner peripheral surface of the cylindrical casing having high heat dissipation performance, the heat dissipation performance of the plurality of power modules, which are heat generating components, can be improved. Further, by continuously providing the smoothing capacitor along the inner surface of the plurality of power modules, the plurality of power modules and the smoothing capacitor can be intensively arranged. Therefore, the dead space in the control device can be reduced, and the space efficiency in the control device can be improved.

[0009] In the above aspect, the rotating electrical machine has a shaft (38) extending in a predetermined axial direction, the casing is provided with a through hole (113) through which the shaft penetrates, and between the through hole and the inner peripheral surface of the casing, the smoothing capacitor and each power module may be arranged in order from the inner side to the outer side in the radial direction of the casing.

[0010] According to this aspect, a plurality of power modules and a smoothing capacitor can be intensively arranged in the space between the through hole and the inner peripheral surface of the casing. Therefore, the space efficiency in the control device can be further improved.

[0011] In the above aspect, the smoothing capacitor may be arranged at intervals in the radial direction of the casing with respect to each of the power modules.

[0012] According to this aspect, mutual thermal influence between a plurality of power modules and a smoothing capacitor (particularly, thermal influence from the plurality of power modules, which are heat-generating components, to the smoothing capacitor) can be suppressed.

[0013] In the above aspect, the axial position of the smoothing capacitor may overlap with the axial positions of the respective power modules.

[0014] According to this aspect, the axial length of the control device can be shortened, and the control device can be flattened, miniaturized, and lightened. Further, by shortening the distance between the plurality of power modules and the smoothing capacitor, an increase in the inductance of the power conversion circuit constituted by the switching elements of the plurality of power modules can be suppressed, and the surge voltage of the power conversion circuit can be suppressed.

[0015] In the above aspect, the control device further has an input terminal (126) connected to a power supply device and an output terminal (211) connected to the terminal (70) on the rotating electrical machine side, and the plurality of power modules and the smoothing capacitor are arranged in one semi-circular portion of the casing, and the input terminal and the output terminal may be arranged at intervals from each other in the other semi-circular portion of the casing.

[0016] According to this aspect, by distributing and arranging the components of the control device in one semi-circular portion and the other semi-circular portion of the casing, the entire internal space of the casing can be effectively utilized.

[0017] In the above aspect, the smoothing capacitor is configured as a capacitor unit in which a plurality of capacitor elements (147) are integrated, and may be bent so as to protrude toward each power module side when viewed from the rotating electric machine side.

[0018] According to this aspect, while aggregating and arranging a plurality of capacitor elements, it is possible to bring them close to each power module. Therefore, the dead space in the control device can be further reduced, and the space efficiency in the control device can be further improved.

[0019] In the above aspect, the control device may further include a plurality of pressing members (78) that press the plurality of power modules against the inner peripheral surface of the casing.

[0020] According to this aspect, by enhancing the adhesion between the plurality of power modules and the inner peripheral surface of the casing, the heat dissipation performance of the plurality of power modules can be further improved.

[0021] In the above aspect, a plurality of pedestal portions (105) are provided on the inner peripheral surface of the casing, a pair of fixing protrusions (106) are provided on the inner surface of each pedestal portion, and an engagement recess (107) is provided between the pair of fixing protrusions. Each pressing member has an engagement piece (138) that engages with the engagement recess of each pedestal portion, and a plurality of protruding pieces (139) that protrude from both sides of the engagement piece and are fixed to the pair of fixing protrusions of each pedestal portion. Each power module may be sandwiched between the engagement piece of each pressing member and the engagement recess of each pedestal portion.

[0022] According to this aspect, by fixing a plurality of protruding pieces to a pair of fixing protrusions having a sufficient thickness, it is possible to sufficiently secure the insertion depth (engagement amount) of the bolts for fixing the plurality of protruding pieces to the pair of fixing protrusions. Further, by bringing each power module into contact with the engaging concave portion of each pedestal portion, the distance between each power module and the outer peripheral surface of the casing (that is, the heat transfer distance until the heat generated by each power module is released to the outer periphery of the casing) can be shortened compared with the case where each power module is brought into contact with the pair of fixing protrusions of each pedestal portion. Therefore, the heat dissipation performance of the plurality of power modules can be further improved.

Effect of the Invention

[0023] According to the above aspect, in a control device integrated with a rotating electric machine such as an electric motor, the arrangement of a plurality of power modules and smoothing capacitors can be devised, and the space efficiency in the control device can be improved.

Brief Description of the Drawings

[0024]

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

Mode for Carrying Out the Invention

[0025] <Aircraft 1> Hereinafter, with reference to the drawings, an aircraft 1 (an example of a moving body) according to an embodiment of the present invention will be described.

[0026] Referring to FIG. 1, the aircraft 1 is an electric vertical take-off and landing aircraft (eVTOL) that can take off and land 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.

[0027] 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.

[0028] A plurality (for example, four) of lifting units 10 for generating a lifting force and a descending force for the aircraft 1 are provided at intervals in the front-rear direction on the left arm 5L and the right arm 5R, respectively. 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 this electric motor.

[0029] <Propulsion Unit 7> Referring to FIG. 2, each propulsion unit 7 includes a support 15, a front and rear propulsion drive 16 (an example of an electric drive) supported by the support 15, a rotary shaft 17 extending in the front-rear direction and rotatably supported by the front and rear propulsion drives 16, and a propulsion propeller 18 fixed to the rear portion of the rotary shaft 17.

[0030] 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.

[0031] The front and rear propulsion drives 16 are housed in the nacelle 20. The front and rear propulsion drives 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 16 will be described later.

[0032] The rotary shaft 17 is housed in the nacelle 20. The rotary 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 rotary shaft 17. The front cover 26 is disposed in front of the front propulsion drive 16. A conical rear cover 27 that expands in diameter forward is fixed to the rear end portion of the rotary shaft 17. The rear cover 27 is disposed behind the central portion of the propulsion propeller 18.

[0033] 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 rotary shaft 17 as the rotary shaft 17 rotates.

[0034] <Propulsion Drive 16> Referring to FIGS. 2 and 3, each propulsion drive device 16 includes an electric motor 31 (an example of a rotating electric 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 circumferences of the electric motor 31, the control device 32, and the fan 33. In FIG. 4, the display of the duct cover 34 is omitted.

[0035] <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.

[0036] The housing 36 is cylindrical and extends in the front-rear direction on the outer circumference of the shaft 38. The housing 36 is disposed on the outer circumferences 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).

[0037] On the outer circumferential surface of the housing 36, a plurality of first cooling fins 42 protrude at intervals in the circumferential direction of the housing 36. The plurality of first cooling fins 42 are integrally formed with the housing 36. Each first cooling fin 42 is flat and extends along the front-rear direction. Each first cooling fin 42 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.

[0038] On the outer circumferential 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 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. The plurality of fastening protrusions 43 are integrally formed with the housing 36.

[0039] Each fastening projection 43 has a rod shape with a rectangular cross-section and extends along the front-rear direction. That is, each fastening projection 43 extends parallel to each first cooling fin 42. Each fastening projection 43 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 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).

[0040] A first bolt hole 44 for fastening the lid 37 to the housing 36 is provided at the front end portion of each fastening projection 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 at the rear end portion of each fastening projection 43. The first bolt hole 44 and the second bolt hole 45 extend along the front-rear direction.

[0041] The lid 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 37 has a disc shape and extends along a plane orthogonal to the front-rear direction. The lid 37 is formed separately from the housing 36. In other embodiments, the lid 37 may be integrally formed with the housing 36.

[0042] A plurality of first fastening pieces 47 project at intervals in the circumferential direction of the lid 37 on the outer peripheral portion of the lid 37. A first fastening hole 48 is provided in each first fastening piece 47 in the front-rear direction, and the lid 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 37 in the front-rear direction. A first bearing 52 is attached to the first through hole 51.

[0043] 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 rotation axis 17 of the propulsion unit 7. Therefore, when the shaft 38 rotates, the entire rotation axis 17 rotates, and the propulsion propeller 18 rotates integrally with the rotation axis 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 arrow X in FIG. 2).

[0044] 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.

[0045] 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.

[0046] 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 a terminal 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 the amount of heat generated by the control device 32. The three motor-side terminals 70 respectively correspond to the U-phase, V-phase, and W-phase of the three-phase alternating current.

[0047] <control device 32> Referring to FIGS. 3 and 4, the control device 32 is integrated with the electric motor 31 and controls the driving of the electric motor 31. That is, the propulsion drive device 16 of the present embodiment is an electromechanical integrated drive device.

[0048] 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). 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 schematic positions of the electronic components E are shown.

[0049] 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.

[0050] The casing 74 has a cylindrical peripheral wall portion 93 that extends in the front-rear direction on the outer periphery of the extension portion 56 of the shaft 38, and a bottom wall portion 94 that closes the opening on the rear side (opposite side 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).

[0051] 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.

[0052] 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.

[0053] A plurality of third fastening pieces 101 project from the rear end portion (the end portion 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.

[0054] 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 positions of the 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.

[0055] Referring to FIGS. 5 and 6, the bottom wall portion 94 of the casing 74 is disc-shaped and extends along a plane perpendicular 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.

[0056] 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.

[0057] 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. An 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.

[0058] Referring to FIG. 6, the resolver 75 is fixed to the central portion of the bottom wall portion 94 of the casing 74. The resolver 75 is provided with a plurality of detection portions (not shown) for detecting the rotation of the extension portion 56 of the shaft 38 at intervals in the circumferential direction.

[0059] 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.

[0060] 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.

[0061] 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.

[0062] 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 circumferentially spaced positions. 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. 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").

[0063] 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.

[0064] The three pressing members 78 are arranged at circumferentially spaced positions. 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 itself 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 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 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.

[0065] 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 pulse 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.

[0066] 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 semi-circular portion (an example of one semi-circular 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 of 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.

[0067] 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 position of the smoothing capacitor 79 in the front-rear direction overlaps with the position of each power module 77 in the front-rear direction.

[0068] Referring to FIGS. 7 and 11, the smoothing capacitor 79 has 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 be convex 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.

[0069] 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 has a case body 153 and three closing members 154 attached to the case body 153.

[0070] 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.

[0071] 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 plurality of 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 plurality of 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 that face the three case openings 166.

[0072] Referring to FIGS. 7 and 10, the three closing members 154 of the capacitor case 148 respectively close the three case openings 166 of the case body 153. Each closing member 154 is made of an insulating resin. Each closing member 154 has 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.

[0073] 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.

[0074] 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 connecting rib 173 of the first closing piece 169.

[0075] 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 part 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.

[0076] 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 part 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.

[0077] 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 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.

[0078] 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 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.

[0079] 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. Thereby, 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 at a circumferential interval from a pair of DC input terminals 126 in the right semi-circular part (an example of the other semi-circular part) of the casing 74. 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. Thereby, 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.

[0080] Referring to FIG. 9, the three current sensors 85 are respectively arranged on three AC lines 207 (three-phase lines) leading 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.

[0081] 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 in the right semi-circular part of the casing 74. The three current sensors 85 are arranged at a circumferential interval. 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.

[0082] 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 on the body 2) provided outside the propulsion drive device 16.

[0083] 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.

[0084] 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.

[0085] Referring to FIG. 5, the partition member 89 partitions the internal space of the housing 36 and the internal space of the casing 74. The partition 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 partition member 89 is housed in the casing 74. In other embodiments, the partition member 89 may be housed in the housing 36 of the electric motor 31. The partition 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 partition member 89. The extension 56 of the shaft 38 penetrates the shaft hole 216.

[0086] <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. On the outer peripheral surface of the rim portion 224, a plurality of air blowing ribs 226 are provided 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.

[0087] <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.

[0088] <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, 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.

[0089] The cooling air introduced into the cooling air passage 229 flows from the front side to the rear side along the outer periphery of the housing 36 and between the multiple first cooling fins 42. This allows the electric motor 31 to be cooled by the cooling air. Next, the cooling air flows from the front side to the rear side along the outer periphery of the peripheral wall portion 93 of the casing 74 and between the multiple second cooling fins 96. This allows the cooling air to cool the housing 36 of the control device 32. 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 of the cooling air passage 229 into the space behind the control device 32.

[0090] <Effects> As described above, the cooling air passage 229 is formed on the outer periphery of the peripheral wall 93 of the casing 74, and therefore the peripheral wall 93 of the casing 74 has high heat dissipation properties. Therefore, in this embodiment, the three power modules 77 are in contact with the inner circumferential surface of the peripheral wall 93 of the casing 74. This makes it possible to improve the heat dissipation properties of the three power modules 77, which are heat-generating components.

[0091] Furthermore, 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., fastening points between the casing 74 and the housing 36), but overlap with the circumferential positions of the plurality of second cooling fins 96. This makes it possible to further improve the heat dissipation performance of the three power modules 77.

[0092] Furthermore, the DC input connector 76 and the communication connector 86 are attached to the bottom wall 94 of the casing 74. This allows a greater number of second cooling fins 96 to be arranged on the peripheral wall 93 of the casing 74 compared to when the DC input connector 76 and the communication connector 86 are attached to the peripheral wall 93 of the casing 74. This further improves the heat dissipation performance of the three power modules 77.

[0093] Further, the smoothing capacitor 79 is continuously provided along the inner surface 77A of the three power modules 77. Thereby, the three power modules 77 and the smoothing capacitor 79 can be intensively arranged. Therefore, the dead space in the control device 32 can be reduced, and the space efficiency in the control device 32 can be increased.

[0094] Also, 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 the plurality of second fastening pieces 97. Thereby, the region around the plurality of second fastening pieces 97 (the region where the power module 77 does not exist) can be used as the fixing region of each pressing member 78. Therefore, the dead space in the control device 32 can be further reduced, and the space efficiency in the control device 32 can be further increased. When the fixing protrusion 106 is arranged such that the circumferential position does not overlap between the plurality of second fastening pieces 97, it is also possible to release the heat transmitted to the fixing protrusion 106 through the surrounding second cooling fins 96.

[0095] Further, the drive substrate 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. By using the capacitor case 148 as a support member for the drive substrate 87 in this way, the number of components can be reduced as compared with the case where a support member for the drive substrate 87 is provided separately from the capacitor case 148. Therefore, the control device 32 can be downsized and lightened.

[0096] Also, the bottom wall portion 94 is formed separately from the peripheral wall portion 93. Therefore, after fixing some components of the control device 32 (for example, the resolver 75, the DC input connector 76, the smoothing capacitor 79, the three current sensors 85, and the communication connector 86) to the bottom wall portion 94 and fixing other components of the control device 32 (for example, the three power modules 77 and the three pressing members 78) to the peripheral wall portion 93, the bottom wall portion 94 and the peripheral wall portion 93 can be assembled. Thereby, the assemblability of the control device 32 can be improved.

[0097] Also, the three power modules 77 are arranged avoiding the top of the casing 74. Therefore, it is possible to suppress the three power modules 77 from being affected by the heat that convects to the top of the casing 74.

[0098] <Modification example> In the above embodiment, the left semi-circular part of the casing 74 is an example of one semi-circular part, and the right semi-circular part of the casing 74 is an example of the other semi-circular part. In other embodiments, conversely, the right semi-circular part of the casing 74 may be an example of one semi-circular part, and the left semi-circular part of the casing 74 may be an example of the other semi-circular part. Furthermore, in other embodiments, the upper or lower semi-circular part of the casing 74 may be an example of one semi-circular part, and the upper or lower semi-circular part on the other side of the casing 74 may be an example of the other semi-circular part. Also, in other embodiments, the boundary between one semi-circular part and the other semi-circular part of the casing 74 may be inclined with respect to the vertical direction and the horizontal direction.

[0099] In the above embodiment, the inrunner-type electric motor 31 is an example of a rotating electric machine. In other embodiments, an outrunner-type electric motor may be an example of a rotating electric machine, or a generator may be an example of a rotating electric machine.

[0100] In the above embodiment, the configuration of the present invention is applied to the propulsion drive device 16. In other embodiments, the configuration of the present invention may be applied to the lifting drive device 12.

[0101] In the above embodiment, 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 (for example, vehicles such as automobiles and motorcycles). Furthermore, in other embodiments, the configuration of the present invention may be applied to a fixedly provided device.

[0102] Although the description of the specific embodiments has been completed above, the present invention is not limited to the above embodiments and modifications, and can be widely modified and implemented.

Description of Reference Numerals

[0103] 31: Electric motor (an example of a rotating electrical machine) 32: Control device 38: Shaft 70: Motor-side terminal (an example of a terminal on the rotating electrical machine side) 74: Casing 77: Power module 77A: Inner surface 78: Pressing member 79: Smoothing capacitor 105: Base portion 106: Fixed protrusion 107: Engaging recess 113: Second through-hole 126: DC input terminal 128: Switching element 130: Inverter (an example of a power conversion circuit) 138: Engaging piece 139: Protruding piece 147: Capacitor element 211: AC output terminal D1: First direction D2: Second direction

Claims

1. A control device integrated with a rotating electrical machine and controlling the drive of the rotating electrical machine, comprising: a plurality of power modules each including a switching element constituting a power conversion circuit; a smoothing capacitor for smoothing the current input to the plurality of power modules; a cylindrical casing housing the plurality of power modules and the smoothing capacitor, wherein the plurality of power modules are in contact with the inner peripheral surface of the casing at intervals in the circumferential direction of the casing, and the smoothing capacitor is a control device for a rotating electrical machine continuously provided along the inner surfaces of the plurality of power modules.

2. The rotating electrical machine has a shaft extending in a predetermined axial direction, the casing is provided with a through hole through which the shaft passes, and between the through hole and the inner peripheral surface of the casing, the smoothing capacitor and each power module are arranged in order from the inner side to the outer side in the radial direction of the casing. The control device for a rotating electrical machine according to claim 1.

3. The control device for a rotating electrical machine according to claim 2, wherein the smoothing capacitor is arranged at a distance from each power module in the radial direction of the casing.

4. The control device for a rotating electrical machine according to claim 2, wherein the axial position of the smoothing capacitor overlaps with the axial positions of the respective power modules.

5. further comprising an input terminal connected to a power supply device and an output terminal connected to a terminal on the rotating electrical machine side, wherein the plurality of power modules and the smoothing capacitor are arranged in one semi-circular portion of the casing, and the input terminal and the output terminal are arranged at intervals from each other in the other semi-circular portion of the casing. The control device for a rotating electrical machine according to any one of claims 1 to 4.

6. The smoothing capacitor is configured as a capacitor unit integrating a plurality of capacitor elements, and is bent so as to protrude toward each power module side when viewed from the rotating electrical machine side. The control device for a rotating electrical machine according to any one of claims 1 to 4.

7. The control device for a rotating electrical machine according to any one of claims 1 to 4, further comprising a plurality of pressing members for pressing the plurality of power modules against the inner peripheral surface of the casing.

8. A plurality of pedestal portions are provided on the inner peripheral surface of the casing, ​ ​ On the inner surface of each pedestal portion, a pair of fixing protrusions are provided, and an engaging recess is provided between the pair of fixing protrusions. Each of the pressing members has an engaging piece that engages with the engaging recess of each pedestal portion, and a plurality of protruding pieces that protrude from both sides of the engaging piece and are fixed to the pair of fixing protrusions of each pedestal portion. The control device for a rotating electric machine according to claim 7, wherein each power module is sandwiched between the engaging piece of each pressing member and the engaging recess of each pedestal portion.

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