Inverter unit, motor unit

Abstract

The inverter unit has: a power supply unit including an inverter circuit; a capacitor connected to the power supply unit; a cooling unit for cooling the power supply unit; and an inverter case for housing the power supply unit, the capacitor, and the cooling unit. The inverter case has a bottom wall, a cylindrical side wall extending upward from the periphery of the bottom wall, and a motor connection unit for fixing the lower surface of the bottom wall toward the motor. The cooling unit and the capacitor are arranged on the bottom wall in a direction along the upper surface of the bottom wall. The power supply unit is located on the upper side of the cooling unit, the lower surface of the capacitor is lower than the lower surface of the cooling unit, and the upper surface of the power supply unit and the upper surface of the capacitor are arranged along the same plane.

Description

Technical Field

[0001] The present invention relates to an inverter unit and a motor unit. Background Art

[0002] In the past, an inverter unit having an inverter for controlling a motor and a housing for accommodating the inverter was known. Japanese Publication No. 2003-199363 discloses an electric drive unit (inverter unit) in which components are stacked and fixed in order of size in consideration of compactness, assemblability, manufacturability, and shock resistance.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Publication No. 2003-199363 Summary of the invention

[0006] Problems to be solved by the invention

[0007] In the motor unit that connects the inverter unit and the motor case, vibrations generated when the motor is driven are transmitted to the inverter unit. Therefore, an inverter unit that is less susceptible to the vibrations is required.

[0008] Means for solving problems

[0009] According to one embodiment of the present invention, there is provided an inverter unit which can be installed on a motor, wherein the inverter unit comprises: a power supply unit which includes an inverter circuit; a capacitor which is connected to the power supply unit; a cooling unit which cools the power supply unit; and an inverter case which accommodates the power supply unit, the capacitor and the cooling unit, the inverter case having a bottom wall, a cylindrical side wall extending upward from the periphery of the bottom wall, and a motor connection portion which fixes the lower surface of the bottom wall toward the motor, the cooling unit and the capacitor are arranged on the bottom wall in a direction along the upper surface of the bottom wall, the power supply unit is located on the upper side of the cooling unit, the lower surface of the capacitor is lower than the lower surface of the cooling unit, and the upper surface of the power supply unit and the upper surface of the capacitor are arranged along the same plane. Effect of the Invention

[0010] The present invention provides, for example, an inverter unit that is less susceptible to the influence of vibration from a motor, and a motor unit having the inverter unit. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 This is a perspective view of the inverter unit according to the present embodiment as viewed from above.

[0012] Figure 2 This is a perspective view of the inverter unit according to the present embodiment as viewed from the bottom.

[0013] Figure 3 It is a cross-sectional view of the inverter unit according to the present embodiment.

[0014] Figure 4 It is a plan view showing the internal structure of the inverter unit according to the present embodiment.

[0015] Figure 5 It is an exploded perspective view showing the structure of the power supply connection portion.

[0016] Figure 6 It is a partial cross-sectional view showing the structure of the circuit connection portion.

[0017] Figure 7 It is a perspective view showing the second terminal support base. DETAILED DESCRIPTION

[0018] Hereinafter, embodiments of the present invention will be described using the drawings.

[0019] In the following description, the gravity direction is specified for description based on the positional relationship when the inverter unit 1 is mounted on a vehicle located on a horizontal road. In addition, in the accompanying drawings, an XYZ coordinate system is appropriately shown as a three-dimensional rectangular coordinate system. In the XYZ coordinate system, the Z-axis direction represents the vertical direction (i.e., the up and down direction), the +Z direction is the upper side (the opposite side of the gravity direction), and the -Z direction is the lower side (the gravity direction). In addition, the X-axis direction is a direction perpendicular to the Z-axis direction, and in this embodiment, it represents the direction along the short side of the inverter unit 1. The Y-axis direction is a direction perpendicular to both the X-axis direction and the Z-axis direction, and in this embodiment, it represents the direction along the long side of the inverter unit 1.

[0020] like Figure 3 As shown, the inverter unit 1 is arranged on the motor unit 3. The motor unit 3 has an inverter unit 1 and a motor 2. The inverter unit 1 is arranged on the upper surface of the motor 2. Therefore, the lower surface of the inverter unit 1 is a motor connection part 10A connected to the motor 2. The motor connection part 10A is a part that mechanically connects the inverter unit 1 and the motor 2. Bolt fastening can be used as a connection structure between the inverter unit 1 and the motor 2. If it is not necessary to load and unload the inverter unit 1 and the motor 2, rivet fastening or welding can also be used. A bracket can also be installed on the motor connection part 10A, and the inverter unit 1 and the motor 2 are connected via the above-mentioned bracket.

[0021] The motor 2 is supplied with an alternating current by the inverter unit 1. The motor 2 is controlled by the inverter unit 1. The inverter unit 1 is connected to a coil wire of a stator of the motor 2.

[0022] The motor unit 3 of this embodiment is mounted on a vehicle using a motor as a power source, such as a hybrid electric vehicle (HEV), a plug-in hybrid electric vehicle (PHV), or an electric vehicle (EV), and is used as a power source. The motor unit 3 may also include a speed reduction device (not shown) for reducing the rotation of the motor 2.

[0023] The inverter unit 1 converts the DC current into AC current and supplies it to the motor 2. Figures 1 to 4 As shown, the inverter unit 1 includes an inverter case 10 , a control substrate 20 , a power supply unit 30 including an inverter circuit, a capacitor 40 , and a plurality of external connection bus bars 50 .

[0024] The inverter case 10 includes a lower housing 11 and a cover member 12 mounted on an opening of the lower housing 11. The lower housing 11 includes a bottom wall 11a and a cylindrical side wall 11b extending upward from the periphery of the bottom wall 11a. The cover member 12 includes a top wall 12a and a cylindrical side wall 12b extending downward from the periphery of the top wall 12a. The lower housing 11 and the cover member 12 are fastened by bolts in a state where the upper end surface 11c of the side wall 11b and the lower end surface 12c of the side wall 12b are opposed to each other.

[0025] The lower case 11 has a storage chamber 13 surrounded by a bottom wall 11a and side walls 11b. The control board 20, the power supply unit 30, the capacitor 40, and the external connection bus bar 50 are arranged inside the storage chamber 13 as viewed from above.

[0026] The storage chamber 13 includes a first storage chamber 13A and a second storage chamber 13B which are separated in the horizontal direction. That is, the inverter case 10 has the first storage chamber 13A and the second storage chamber 13B. The first storage chamber 13A and the second storage chamber 13B are arranged along the long side direction (Y-axis direction) of the inverter case 10. The power supply unit 30 and the external connection bus bar 50 are arranged in the first storage chamber 13A. The control substrate 20 and the capacitor 40 are arranged in the second storage chamber 13B.

[0027] like Figure 4 As shown in FIG. 1 , the first storage chamber 13A is roughly rectangular in plan view. Figure 2 as well as Figure 3 As shown, a cooling unit 60 is provided at the bottom of the first storage chamber 13A. That is, the inverter unit 1 has a cooling unit 60. The cooling unit 60 has a refrigerant flow path 11d. The refrigerant flow path 11d is a recessed portion opened on the upper surface side of the bottom wall 11a. The refrigerant flow path 11d is roughly rectangular in a top view. The refrigerant flow path 11d is connected to the piping connection terminals 14 and 15 on the side of the lower shell 11 via a tubular flow path penetrating the bottom wall 11a. The piping connection terminals 14 and 15 are connected to external refrigerant piping. The power supply part 30 is fixed to the refrigerant flow path 11d.

[0028] The power supply unit 30 includes a power supply substrate 31 and a semiconductor module 32 located below the power supply substrate 31. In the present embodiment, both the power supply substrate 31 and the semiconductor module 32 are in the form of a flat plate.

[0029] The semiconductor module 32 has a three-phase inverter having six IGBTs (insulated gate bipolar transistors) built into the housing. Figure 3 As shown, the semiconductor module 32 has a heat sink 32a, which is composed of a plurality of columnar bodies extending downward from the lower surface of the semiconductor module 32. The semiconductor module 32 is fixed to the bottom wall 11a in a state of covering the refrigerant flow path 11d from the upper side. The heat sink 32a is arranged in the refrigerant flow path 11d. An annular sealing member 33 is arranged around the refrigerant flow path 11d. The refrigerant flow path 11d is sealed by the sealing member 33 sandwiched between the upper surface of the bottom wall 11a and the semiconductor module 32.

[0030] A power substrate 31 for driving the semiconductor module 32 is arranged on the upper surface of the semiconductor module 32. The power substrate 31 and the semiconductor module 32 are electrically connected via a plurality of connection pins 34 extending upward from the semiconductor module 32. In the present embodiment, the semiconductor module 32 is located on the cooling unit 60, and the power substrate 31 is located on the semiconductor module 32. According to this structure, since the semiconductor module 32, which is more likely to generate heat than the power substrate 31, is arranged directly above the cooling unit 60, the entire power supply unit 30 can be efficiently cooled. In addition, by arranging the power substrate 31 connected to the control substrate 20 to the upper side than the semiconductor module 32, electrical connection between the substrates becomes easy.

[0031] like Figure 4 As shown, the second storage chamber 13B is a generally rectangular shape that is thinner and longer in the X-axis direction than the first storage chamber 13A. A capacitor 40 is fixed to the bottom of the second storage chamber 13B. The control substrate 20 is fixed to the upper surface of the capacitor 40 via a bracket 25. The circuit components mounted on the lower surface of the control substrate 20 and the capacitor 40 are insulated by the bracket 25. The bracket 25 can be fixed to the inverter case 10. In addition, the control substrate 20 can also be directly fixed to the upper surface 40b of the capacitor 40 when possible.

[0032] The control board 20 supplies a drive signal to the motor 2 via the power supply unit 30 to control the motor 2. The control board 20 is electrically connected to an encoder such as a resolver provided on the motor unit 3. The control board 20 performs feedback control on the rotation speed of the motor 2 based on the rotation information of the motor 2 output from the encoder.

[0033] In the inverter unit 1 of this embodiment, Figure 3As shown, the cooling unit 60 and the capacitor 40 are arranged in a direction along the upper surface of the bottom wall 11a of the lower housing 11 (in the Y-axis direction in this embodiment). The power supply unit 30 is located on the upper side of the cooling unit 60, and the lower surface 40a of the capacitor 40 is lower than the lower surface 60a of the cooling unit 60.

[0034] In this embodiment, if Figure 2 as well as Figure 3 As shown in the figure, the lower surface 60a of the cooling unit 60 is the lower surface of the two shell protrusions 61a and 61b protruding downward from the lower surface of the lower shell 11. A tubular flow path connecting the refrigerant flow path 11d and the pipe connection terminal 14 is provided inside the shell protrusion 61a, and a tubular flow path connecting the refrigerant flow path 11d and the pipe connection terminal 15 is provided inside the shell protrusion 61b. Therefore, the lower surface 60a of the cooling unit 60 is the surface located at the lower side of the part constituting the flow path of the refrigerant in the lower shell 11.

[0035] According to the above structure, among the power supply unit 30, the capacitor 40 and the cooling unit 60, the lower surface 40a of the capacitor 40 is located at the lowermost side. Therefore, in the inverter unit 1 of the present embodiment having the motor connection portion 10A on the lower surface, the capacitor 40 as a heavy object is arranged at a position closest to the motor 2. In the case where the inverter unit 1 swings due to the vibration transmitted from the motor 2, the farther away from the motor 2, the larger the amplitude. By adopting the above structure, the amplitude of the capacitor 40 arranged near the motor 2 can be made smaller. The amplitude of the capacitor 40 with the heaviest weight becomes smaller, thereby reducing the stress acting on the inverter unit 1 due to the vibration. Therefore, according to the present embodiment, an inverter unit 1 that is not easily affected by the vibration of the motor 2 is provided.

[0036] Furthermore, in the present embodiment, the upper surface 30a of the power supply unit 30 and the upper surface 40b of the capacitor 40 are arranged along the same plane. That is, the upper surface 30a of the power supply unit 30 is substantially parallel to the upper surface 40b of the capacitor 40. The parallelism between the upper surface 30a and the upper surface 40b is within ±5°. The above-mentioned parallel angle is preferably within ±1°. In the present embodiment, the upper surface 30a of the power supply unit 30 is the upper surface of the power substrate 31. In addition, when the semiconductor module 32 is arranged on the upper side of the power substrate 31 in the power supply unit 30, the upper surface 30a of the power supply unit 30 becomes the upper surface of the semiconductor module 32.

[0037] According to the above structure, in the inverter unit 1 of the present embodiment, the housing of the capacitor 40 is unlikely to interfere with the housing of the power supply unit 30. Therefore, in the inverter unit 1, the capacitor 40 and the power supply unit 30 can be arranged close to each other in the horizontal direction (Y-axis direction). As a result, the wiring connecting the capacitor 40 and the power supply unit 30 can be shortened. In the case where the wiring of the DC power supply from the power supply to the IGBT as a switching element is long, the surge voltage at the time of shutdown becomes higher because the inductive reactance of the wiring becomes larger. In the present embodiment, since the wiring length of the DC power supply to the IGBT can be shortened, the surge voltage can be suppressed. If the surge voltage can be suppressed, the switching time of the IGBT can be shortened, so the efficiency of the inverter can be improved. In addition, by improving the efficiency, the effect of reducing heat generation can also be obtained.

[0038] like Figure 1 as well as Figure 4 As shown, the capacitor 40 is connected to the external power supply device 9 via the wiring 9a. The wiring 9a is connected to the capacitor input terminal 41 of the capacitor 40 via the wiring terminal 9b provided at the end of the wiring 9a. The external power supply device 9 is, for example, a secondary battery mounted on a vehicle. The inverter unit 1 converts the direct current supplied from the external power supply device 9 into an alternating current and supplies it to the motor 2 via the external connection bus bar 50.

[0039] In this embodiment, the two wirings 9a are fixed to the inverter case 10 by means of a mounting member 9c supporting the wirings 9a. The mounting member 9c is bolted to the outer side of the side wall 11b of the lower housing 11. The wirings 9a extending from the mounting member 9c to the front end side extend into the second storage chamber 13B through a through hole 11e provided in the side wall 11b.

[0040] In the second storage chamber 13B, the wiring terminal 9b and the capacitor input terminal 41 are fastened by bolts 84. That is, a power connection portion 80 for connecting the wiring 9a extending from the external power supply device 9 and the capacitor 40 is arranged in the second storage chamber 13B of the inverter case 10. According to this structure, since the wiring 9a is introduced and connected in the area where the capacitor 40 is stored, that is, the second storage chamber 13B, a bus bar is not used, and the capacitor 40 and the external power supply device 9 can be connected with a minimum space. Therefore, according to this embodiment, the inverter unit 1 can be miniaturized.

[0041] Figure 5 It is an exploded perspective view showing the power connection portion 80 .

[0042] The power connection portion 80 includes a bolt (first fixing member) 84 that connects the capacitor input terminal 41 extending from the capacitor 40 and the wiring terminal 9b located at the terminal end of the wiring 9a, and a first terminal support 81 that supports the capacitor input terminal 41 and the wiring terminal 9b from the lower side. The bolt 84 as the first fixing member fixes the capacitor input terminal 41 and the wiring terminal 9b to the first terminal support 81.

[0043] like Figure 5 As shown, the first terminal support 81 is a rod-shaped member extending in the Y-axis direction along the side surface of the capacitor 40. The first terminal support 81 has two first terminal fixing portions 81a arranged at intervals from each other along the length direction (Y-axis direction). That is, the first terminal support 81 has a plurality of first terminal fixing portions 81a arranged in a direction intersecting the up-down direction.

[0044] The first terminal support 81 has a first partition wall 81b extending in the up-down direction between adjacent first terminal fixing portions 81a. According to this structure, the wiring terminals 9b can be insulated from each other by the first partition wall 81b. In the case of the present embodiment, the first partition wall 81b is arranged at three locations including both ends of the first terminal support 81, and is arranged to sandwich each first terminal fixing portion 81a in the horizontal direction. In the present embodiment, the first partition wall 81b also acts as a positioning component of the wiring terminal 9b when connecting the capacitor input terminal 41 and the wiring terminal 9b.

[0045] The first terminal support 81 has a flange 81c at each of the two ends in the longitudinal direction. The flange 81c has a through hole that passes through the flange 81c in the vertical direction. The first terminal support 81 is fastened to the bottom wall 11a of the lower housing 11 by bolts passing through the through holes of the flange 81c.

[0046] The capacitor input terminal 41 and the wiring terminal 9b of the capacitor 40 are fastened to the first terminal fixing portion 81a of the first terminal support 81. The capacitor input terminal 41 is arranged on the upper surface of the first terminal fixing portion 81a, and the wiring terminal 9b is arranged overlappingly on the upper surface of the capacitor input terminal 41. The bolt 84 passes through the capacitor input terminal 41 and the wiring terminal 9b, and is screwed into the threaded hole 81d of the first terminal fixing portion 81a. According to this structure, the capacitor input terminal 41 and the wiring terminal 9b are fixed to the lower housing 11 via the first terminal support 81. Since the wiring 9a and the capacitor 40 are firmly fixed, it is also difficult to cause loosening of the connection due to vibration during use.

[0047] like Figure 1As shown, the cover component 12 includes: a cover body 12A, which is connected to the upper end of the side wall 11b of the lower shell 11 and covers the power supply unit 30 and the capacitor 40 from the upper side; an access port 12B, which is arranged on the cover body 12A and opens on the upper side of the power connection part 80; and a port cover 12C, which can be detachably installed on the access port 12B.

[0048] like Figure 4 As shown, the end cover 12C is provided at a position covering the power connection part 80 from the upper side. According to this structure, the power connection part 80 can be operated only by removing the end cover 12C from the cover body 12A. That is, the operator can perform the wiring connection operation while covering the cover body 12A with other components. Thus, during the wiring connection operation, dust can be prevented from adhering to the control substrate 20 and the power supply unit 30.

[0049] In the present embodiment, the bolt 84 as the first fixing member extends in the up-down direction and is screwed in from the upper side to the lower side. Therefore, the bolt 84 can be operated from the upper side when the end cover 12C or the cover member 12 is removed. According to this structure, the wiring 9a and the capacitor 40 can be easily connected. It is possible to provide an inverter unit 1 with excellent assembly workability.

[0050] In the inverter unit 1 of the present embodiment, the control substrate 20 and the power substrate 31 of the power supply unit 30 are provided as different substrates, and the control substrate 20 is arranged on the upper side of the capacitor 40. Figure 3 As shown in the figure, since the bottom surface of the capacitor 40 is positioned lower than the cooling unit 60, it is easy to provide a space on the upper side of the capacitor 40. According to this structure, the unevenness of the upper surface of the inverter unit 1 can be alleviated compared with the structure in which the control substrate 20 is arranged on the power supply unit 30. Therefore, by using the inverter unit 1 in which the control substrate 20 is arranged on the capacitor 40, the overall miniaturization of the motor unit 3 can be achieved.

[0051] like Figure 4 As shown, the semiconductor module 32 has six inverter input terminals 35 on the side facing the capacitor 40. The inverter input terminals 35 are connected to six capacitor output terminals 42 (see FIG. 1 ) extending from the capacitor 40 in the circuit connection portion 90 connecting the power supply portion 30 and the capacitor 40. Figure 6 )connect.

[0052] Figure 6 2 is a cross-sectional view showing the circuit connection portion 90 .

[0053] The circuit connection portion 90 includes a second terminal support platform 91 that supports the inverter input terminal 35 extending from the power supply portion 30 and the capacitor output terminal 42 extending from the capacitor 40 from the lower side, and a bolt (second fixing member) 94 that connects the inverter input terminal 35 and the capacitor output terminal 42 and is fixed to the second terminal support platform 91.

[0054] Figure 7 It is a perspective view of the second terminal support base 91 .

[0055] The second terminal support 91 is a rod-shaped component extending in the X-axis direction along the side surface of the capacitor 40. The second terminal support 91 has six second terminal fixing portions 91a arranged at intervals along the length direction (X-axis direction). That is, the second terminal support 91 has a plurality of second terminal fixing portions 91a arranged in a direction intersecting the up-down direction. In addition, the second terminal support 91 and the first terminal support 81 may be provided as one component.

[0056] The second terminal support 91 has a second partition wall 91b extending in the vertical direction between adjacent second terminal fixing portions 91a. According to this structure, the inverter input terminal 35 and the capacitor output terminal 42 can be insulated from each other by the second partition wall 91b. In the case of this embodiment, the second partition wall 91b is arranged at a plurality of locations including both ends of the second terminal support 91, and is arranged to sandwich each second terminal fixing portion 91a in the horizontal direction.

[0057] The second terminal support platform 91 has a flange portion 91c at each end in the length direction (X-axis direction). The flange portion 91c has a through hole that penetrates the flange portion 91c in the up-down direction. The flange portion 91c has a positioning pin 91e that protrudes downward from the front end of the flange portion 91c. The positioning pin 91e is inserted into the positioning hole opened on the upper surface of the bottom wall 11a to position the second terminal support platform 91 on the bottom wall 11a. The second terminal support platform 91 is fastened to the bottom wall 11a of the lower housing 11 by bolts passing through the through holes of the flange portion 91c.

[0058] The capacitor output terminal 42 and the inverter input terminal 35 are fastened to the second terminal fixing portion 91a of the second terminal support stand 91. Figure 6As shown in FIG. 1 , the inverter input terminal 35 is arranged on the upper surface of the second terminal fixing portion 91a, and the capacitor output terminal 42 is arranged on the upper surface of the inverter input terminal 35 in an overlapping manner. The bolt 94 passes through the capacitor output terminal 42 and the inverter input terminal 35, and is screwed into the threaded hole 91d of the second terminal fixing portion 91a. According to this structure, the capacitor output terminal 42 and the inverter input terminal 35 are fixed to the lower housing 11 via the second terminal support 91. Since the power supply unit 30 and the capacitor 40 are firmly fixed, it is also difficult to cause loosening of the connection due to vibration during use.

[0059] The second terminal support platform 91 has a columnar portion 91f extending in the up-down direction on the back side of each second terminal fixing portion 91a. The lower end surface of the columnar portion 91f abuts against the upper surface of the bottom wall 11a. When the bolt 94 is screwed into the threaded hole 91d, the columnar portion 91f supports the second terminal fixing portion 91a from the bottom. By providing the columnar portion 91f, the lower portion of the second terminal support platform 91 can be thinned, and the second terminal support platform 91 can be made lighter without compromising the strength.

[0060] The semiconductor module 32 has three output terminals 36 on the side opposite to the capacitor 40. That is, the power supply unit 30 has a plurality of output terminals 36. The three output terminals 36 are respectively connected to different relay bus bars 57. The three relay bus bars 57 extend in the horizontal direction from the connection positions with the output terminals 36 of the power supply unit 30.

[0061] The three relay bus bars 57 are connected to different external connection bus bars 50 respectively. Figure 2 as well as Figure 3 As shown, the three external connection busbars 50 are straight metal plates extending in the up-down direction. The external connection busbars 50 are connected to the relay busbars 57 at the upper end. In the case of this embodiment, the external connection busbars 50 and the relay busbars 57 are fastened using bolts 54. The connection portion between the external connection busbars 50 and the relay busbars 57 is covered with a protective cover 55a.

[0062] The external connection bus bar 50 extends downward from the connection position with the relay bus bar 57, passes through the bottom wall 11a of the lower case 11, and extends to the outside of the lower case 11. The external connection bus bar 50 protruding from the lower case 11 is electrically connected to the stator of the motor 2.

[0063] Description of symbols

[0064] 1: inverter unit; 2: motor; 3: motor unit; 9: external power supply device; 9a: wiring; 9b: wiring terminal; 10: inverter housing; 10A: motor connection portion; 11a: bottom wall; 11b, 12b: side walls; 12: cover member; 12A: cover body; 12B: access port; 12C: port cover; 13A: first storage chamber; 13B: second storage chamber; 20: control substrate; 30: power supply unit; 30a, 40b: upper surface; 31: power substrate; 32: semiconductor module; 3 5: inverter input terminal; 36: output terminal; 40: capacitor; 40a, 60a: lower surface; 41: capacitor input terminal; 42: capacitor output terminal; 60: cooling part; 80: power supply connection part; 84: bolt (first fixing part); 81: first terminal support platform; 81a: first terminal fixing part; 81b: first partition wall; 90: circuit connection part; 91: second terminal support platform; 91a: second terminal fixing part; 91b: second partition wall; 94: bolt (second fixing part).

Claims

1. An inverter unit, which can be mounted on a motor, wherein: The inverter unit has: a power supply unit including an inverter circuit; A capacitor connected to the power supply unit; a cooling unit for cooling the power supply unit; and an inverter box housing the power supply unit, the capacitor and the cooling unit, The inverter housing includes a bottom wall, a cylindrical side wall extending upward from a peripheral edge of the bottom wall, and a motor connection portion that fixes the lower surface of the bottom wall toward the motor. The cooling unit and the capacitor are arranged on the bottom wall in a direction along the upper surface of the bottom wall. The power supply unit is located on the upper side of the cooling unit. The lower surface of the capacitor is located below the lower surface of the cooling unit. The upper surface of the power supply unit and the upper surface of the capacitor are arranged along the same plane, The cooling unit has a refrigerant flow path provided on the bottom wall.

2. The inverter unit according to claim 1, wherein: The inverter unit includes a control substrate connected to the power supply unit. The control substrate is located on an upper side of the capacitor.

3. The inverter unit according to claim 1 or 2, wherein: The power supply unit includes a semiconductor module for converting current and a power substrate for driving the semiconductor module. The semiconductor module is located on the cooling portion, The power substrate is located on the semiconductor module.

4. The inverter unit according to claim 1 or 2, wherein: The inverter housing has a first storage chamber for storing the power supply unit and a second storage chamber for storing the capacitor. The second storage chamber is provided with a power supply connection portion for connecting a wiring extending from an external power supply device and the capacitor.

5. The inverter unit according to claim 4, wherein: The power supply connection portion includes a first fixing member that connects a capacitor input terminal extending from the capacitor and a wiring terminal located at a terminal end of the wiring. The inverter housing has a cover member that covers at least the power connection portion from the upper side. The first fixing member can be operated from the upper side in a state where the cover member is removed.

6. The inverter unit according to claim 5, wherein: The cover component has: a cover body connected to the upper end of the side wall and covering the power supply unit and the capacitor from the upper side; an access port disposed on the cover body and opening on an upper side of the power connection portion; as well as A port cover is detachably mounted on the access port.

7. The inverter unit according to claim 5, wherein: The power connection portion has: a first fixing member connecting a capacitor input terminal extending from the capacitor and a wiring terminal located at a terminal end of the wiring; as well as a first terminal support base that supports the capacitor input terminal and the wiring terminal from below, The first fixing member fixes the capacitor input terminal and the wiring terminal to the first terminal support base.

8. The inverter unit according to claim 7, wherein: The first terminal support base has a plurality of first terminal fixing portions to which the capacitor input terminals and the wiring terminals are fixed. The plurality of first terminal fixing portions are arranged in a direction intersecting the up-down direction. A first partition wall extending in the up-down direction is arranged between the adjacent first terminal fixing portions.

9. The inverter unit according to claim 1 or 2, wherein: The inverter housing has a circuit connection portion for connecting the power supply portion and the capacitor. The circuit connection portion has: a second terminal support base that supports, from a lower side, an inverter input terminal extending from the power supply unit and a capacitor output terminal extending from the capacitor; and A second fixing member connects the inverter input terminal and the capacitor output terminal and is fixed to the second terminal support stand.

10. The inverter unit according to claim 9, wherein: The second terminal support base has a plurality of second terminal fixing portions to which the inverter input terminal and the capacitor output terminal are fixed. The plurality of second terminal fixing portions are arranged in a direction intersecting the up-down direction. A second partition wall extending in the up-down direction is arranged between the adjacent second terminal fixing portions.

11. A motor unit comprising: The inverter unit according to any one of claims 1 to 10; and The motor is supplied with AC current by the inverter unit.

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