Drive device

Abstract

The drive device includes a motor, an inverter, a transmission mechanism and a housing. The motor has a motor-side connection portion protruding from the stator and electrically connected to the inverter. The motor axis and the output axis extend parallel to each other. The inverter is located in a second direction orthogonal to the first direction relative to the motor axis, and extends in a third direction orthogonal to the first and second directions. When viewed from the first direction, an imaginary straight line passing through the motor axis and the output axis extends in the third direction. When viewed from the second direction, the inverter storage portion overlaps with the motor axis and the output axis. The inverter storage portion has a boundary wall portion that is located on the side of the inverter storage portion on the imaginary straight line in the second direction. In the second direction, the distance between the boundary wall portion and the output axis is smaller than the distance between the boundary wall portion and the motor axis. The motor-side connection portion has a portion that is located on the side opposite to the output axis than the motor axis in the third direction.

Description

Technical Field

[0001] The present invention relates to a drive device. This application claims priority based on Japanese Patent Application No. 2019-227659 filed on December 17, 2019, the contents of which are incorporated herein by reference. Background Art

[0002] Conventionally, there is known a drive device that integrates a motor, an inverter, and a transmission mechanism. For example, Patent Document 1 discloses a drive device that integrates a motor, an inverter, and a transmission mechanism.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: International Publication No. 2019 / 076696 Summary of the Invention

[0006] Technical problem to be solved by the invention

[0007] When the drive device is used as a drive device for a vehicle, it is required to reduce the size of the motor, the inverter, and the transmission mechanism.

[0008] One of the objects of the present invention is to provide a driving device that can be miniaturized.

[0009] Technical solutions used to solve technical problems

[0010] One aspect of the drive device of the present invention includes: a motor having a rotor and a stator, the rotor rotating about a motor axis extending in a first direction; an inverter supplying electric power to the motor; a transmission mechanism transmitting rotation output from the motor to an axle rotating about an output axis; and a housing having a motor housing portion, an inverter housing portion, and a gear housing portion, the motor housing portion housing the motor, the inverter housing portion housing the inverter, and the gear housing portion housing the transmission mechanism. The motor has a motor-side connection portion protruding from the stator and electrically connected to the inverter. The motor axis and the output axis extend parallel to each other. The inverter is located in a second direction orthogonal to the first direction relative to the motor axis and extends in a third direction orthogonal to the first and second directions. When viewed from the first direction, an imaginary straight line passing through the motor axis and the output axis extends in the third direction. When viewed from the second direction, the inverter housing portion overlaps with the motor axis and the output axis. The inverter housing portion includes a boundary wall portion located on the side of the inverter housing portion closer to the imaginary straight line in the second direction. In the second direction, a distance between the boundary wall portion and the output axis is smaller than a distance between the boundary wall portion and the motor axis. The motor-side connecting portion includes a portion located on a side of the motor axis opposite to the output axis in the third direction.

[0011] One embodiment of the drive device of the present invention includes: a motor having a rotor rotatable about a motor axis extending in a first direction; an inverter controlling the current supplied to the motor; a transmission mechanism transmitting power from the motor to an axle; and a housing housing the motor, the inverter, and the transmission mechanism. The housing includes an inverter housing for housing the inverter. The transmission mechanism includes a reduction gear that reduces the rotation of the motor and a differential that transmits the motor's rotation, reduced in speed by the reduction gear, to the axle. When viewed from the first direction, the inverter housing overlaps with the differential.

[0012] Effects of the Invention

[0013] According to one aspect of the present invention, a drive device in which a motor, an inverter, and a transmission mechanism are integrated can be miniaturized. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 This is a conceptual diagram of the driving device according to the first embodiment.

[0015] Figure 2This is a view of the motor, transmission mechanism, and inverter in the drive device according to the first embodiment, as viewed from the axial direction.

[0016] Figure 3 It is a perspective view of the motor, the transmission mechanism, and the inverter in the drive device according to the first embodiment.

[0017] Figure 4 It is a side view showing a driving device according to a second embodiment.

[0018] Figure 5 It will Figure 4 The V portion is enlarged and shown in a perspective view. DETAILED DESCRIPTION

[0019] <First embodiment>

[0020] Reference Figures 1 to 3 , a driving device 1 according to a first embodiment of the present invention is described. In the following description, the direction of gravity is defined based on the positional relationship when the driving device 1 is installed 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 orthogonal to the Z-axis direction, which represents the front and rear direction of the vehicle on which the driving device 1 is installed, the +X direction is the front of the vehicle, and the -X direction is the rear of the vehicle.

[0021] However, the +X direction can also be the rear of the vehicle, and the -X direction can be the front of the vehicle. The Y-axis direction is perpendicular to both the X-axis and the Z-axis directions, representing the width of the vehicle (left-right direction). The +Y direction is the left side of the vehicle, and the -Y direction is the right side of the vehicle. However, in the case where the +X direction is the rear of the vehicle, the +Y direction can also be the right side of the vehicle, and the -Y direction can be the left side of the vehicle. In other words, regardless of the direction of the X-axis, the +Y direction is on one side of the vehicle's left-right direction, and the -Y direction is on the other side of the vehicle's left-right direction.

[0022] In the following description, unless otherwise specified, the direction parallel to the motor axis J2 of the motor 2 (Y-axis direction) is referred to as the "axial direction", the radial direction centered on the motor axis J2 is referred to as the "radial direction", and the circumferential direction centered on the motor axis J2, that is, the direction around the motor axis J2, is referred to as the "circumferential direction". The above-mentioned "parallel directions" also include substantially parallel directions. Specifically, the "parallel" in this embodiment means that the angle between a pair of components that run (extend) in parallel in substantially the same direction, that is, the angle (inclination angle) at which the other side is inclined with respect to the other side is 30° or less. In addition, in this embodiment, one axial side corresponds to the +Y direction, and the other axial side corresponds to the -Y direction. In this embodiment, the direction in which the motor axis J2 extends, that is, the Y-axis direction, corresponds to the first direction. In addition, the X-axis direction corresponds to the second direction, and the Z-axis direction corresponds to the third direction.

[0023] The drive device 1 of the present 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 the power source.

[0024] like Figure 1 As shown, the drive device 1 includes a motor 2, a transmission mechanism 3, a housing 6, oil O housed in the housing 6, and an inverter unit (inverter). The inverter unit is housed in the inverter housing 8 of the housing 6. In this embodiment, the inverter unit includes an inverter and an inverter cover. In other words, the drive device 1 includes an inverter and an inverter cover. The inverter cover blocks the opening of the inverter housing 8. The inverter cover is fixed to the opening 661 of the inverter housing 8 described later by screw members or the like.

[0025] The motor 2 includes a rotor 20, a stator 30, and a motor-side connection portion 35. The rotor 20 rotates about a horizontally extending motor axis J2, and the stator 30 is located radially outward of the rotor 20. The motor axis J2 extends in a first direction. The housing 6 includes a motor housing portion 60 that houses the motor 2, a gear housing portion 62 that houses the transmission mechanism 3, a wall portion 63 that separates the motor housing portion 60 from the gear housing portion 62, and an inverter housing portion 8 that houses the inverter.

[0026] The motor 2 is an inner rotor type motor in which a rotor 20 is arranged inside a stator 30. The rotor 20 includes a shaft 21, a rotor core 24, and rotor magnets (not shown).

[0027] The shaft body 21 is centered about the motor axis J2, which extends horizontally and in the width direction of the vehicle. The shaft body 21 is a hollow shaft with a hollow portion 22 inside. The shaft body 21 protrudes from the motor housing 60 into the gear housing 62. The end of the shaft body 21 that protrudes into the gear housing 62 is connected to the transmission mechanism 3. Specifically, the shaft body 21 is connected to the first gear 41.

[0028] The stator 30 surrounds the rotor 20 from the radial outside. The stator 30 has a stator core 32, a coil 31, and an insulator (not shown), which is sandwiched between the stator core 32 and the coil 31. The stator 30 is retained in the motor housing 60. In this embodiment, the stator 30 is retained in the motor housing 60 by a stator support member 33. Grooves are provided on the inner circumference or outer circumference of the stator support member 33 to form a water path with the stator or the motor housing 60. Cooling water is supplied to the water path from a radiator (not shown), thereby cooling the stator 30. The coil 31 is connected to the inverter unit.

[0029] like Figure 2 As shown, the motor-side connection portion 35 protrudes from the stator 30. The motor-side connection portion 35 is a wiring member connected to the coil 31, such as a busbar. The motor-side connection portion 35 may also include a plurality of wires extending from the coil 31 and bundled together. The motor-side connection portion 35 protrudes radially outward from the stator core 32. The motor-side connection portion 35 is electrically connected to the inverter.

[0030] like Figure 1 As shown, the transmission mechanism 3 transmits the rotation output from the motor 2 to the axle 55 that rotates around the output axis J5. In other words, the transmission mechanism 3 transmits the power of the motor 2 to the axle 55. The motor axis J2 and the output axis J5 extend parallel to each other. In this embodiment, the motor axis J2 and the output axis J5 are arranged in a substantially vertical direction. Figure 2 As shown, when viewed from the first direction (Y-axis direction), the imaginary straight line VL passing through the motor axis J2 and the output axis J5 extends in the third direction, namely the Z-axis direction. That is, when viewed from the first direction, the imaginary straight line VL extends parallel to the third direction.

[0031] like Figure 1 As shown, the transmission mechanism 3 is housed in the gear housing portion 62. The transmission mechanism 3 is connected to the shaft body 21 on the other side of the motor axis J2 in the axial direction. The transmission mechanism 3 includes a reduction gear 4 that reduces the rotation of the motor 2, and a differential device 5 that transmits the rotation of the motor 2 reduced in the reduction gear 4 to the axle 55. The torque output from the motor 2 is transmitted to the differential device 5 via the reduction gear 4.

[0032] The reduction gear 4 is connected to the shaft 21 of the motor 2. The reduction gear 4 has a first gear 41, a second gear 42, a third gear 43 and an intermediate shaft 45. The first gear 41 is connected to the shaft 21 of the motor 2. The first gear 41 is fixed to the shaft 21 of the rotor 20. The intermediate shaft 45 extends along an intermediate axis J4 parallel to the motor axis J2. The second gear 42 and the third gear 43 are fixed to both ends of the intermediate shaft 45. The second gear 42 and the third gear 43 are connected by the intermediate shaft 45. The second gear 42, the intermediate shaft 45 and the third gear 43 rotate around the intermediate axis J4. Figure 2 As shown, the middle axis J4 is located in the second direction (X-axis direction) relative to the virtual line VL. That is, the middle axis J4 is arranged away from the virtual line VL in the second direction. In this embodiment, the middle axis J4 is located on the front side (+X side) of the virtual line VL.

[0033] The second gear 42 is a secondary gear. The second gear 42 is meshed with the first gear 41. Figure 1 As shown, the third gear 43 meshes with the ring gear 51 of the differential device 5. The intermediate shaft 45 is connected to the pump unit 10 described later.

[0034] The torque output from motor 2 is transmitted to ring gear 51 of differential device 5 via motor 2's shaft 21, first gear 41, second gear 42, intermediate shaft 45, and third gear 43. The gear ratios and number of gears can be varied to suit the desired reduction ratio. Speed ​​reduction device 4 is a parallel-axis gear type speed reducer in which the axes of the gears are arranged parallel to each other.

[0035] The differential 5 transmits the torque output from the motor 2 to the vehicle's axle 55. When the vehicle turns, the differential 5 absorbs the speed difference between the left and right wheels and transmits the same torque to the axles (drive shafts) 55 of both wheels. The differential 5 includes a ring gear 51 that meshes with the third gear 43 of the reduction gear 4, a differential case 52, and other components (not shown). The ring gear 51 is connected to the reduction gear 4 and rotates about the output axis J5.

[0036] Oil O is disposed in at least one of the motor housing 60 and the gear housing 62. An oil reservoir P is provided in the lower region of the gear housing 62 to store the oil O. In this embodiment, the bottom of the motor housing 60 is positioned above the bottom of the gear housing 62. This configuration allows the oil O, which has cooled the motor 2, to be easily recovered from the lower region of the motor housing 60 to the oil reservoir P of the gear housing 62.

[0037] A portion of the differential 5 is immersed in the oil reservoir P. The oil O accumulated in the oil reservoir P is lifted up by the operation of the differential 5. A portion of the lifted oil O is supplied to the shaft 21. However, it is not necessary to supply the oil O to the shaft 21. The remaining portion of the oil O diffuses within the gear housing 62 and is supplied to the various gears of the reduction gear 4 and the differential 5. The oil O used to lubricate the reduction gear 4 and the differential 5 drips and is recovered in the oil reservoir P located below the gear housing 62.

[0038] The inverter unit controls the current supplied to the motor 2. The inverter unit is fixed to the housing 6 and housed in the inverter housing 8. The inverter supplies power to the motor 2. Figure 2 As shown, the inverter is located forward of the motor axis J2, i.e., in the second direction (X-axis direction), and extends in the third direction (Z-axis direction). According to this embodiment, since the inverter extends in the third direction, i.e., the longitudinal direction of the drive device 1 where the motor 2 and the transmission mechanism 3 are arranged, the dimension of the inverter unit in the second direction can be suppressed accordingly, resulting in a thinner design.

[0039] like Figure 1 As shown, the pump section 10 is an oil pump driven by the motor 2 via the first gear 41, the second gear 42 and the intermediate shaft 45. The pump section 10 draws up the oil O from the oil reservoir P. The motor 2 rotates the pump mechanism of the pump section 10. In the drive device 1, the rotation axis J6 of the pump mechanism is parallel to the motor axis J2. Since the pump section 10 can be driven by the motor 2, the oil O can be drawn up without providing additional auxiliary equipment such as a pump drive motor. In addition, since the pump section 10 can be driven without changing the rotation direction of the intermediate shaft 45 by means of bevel gears, etc., the size of the drive device 1 can be miniaturized.

[0040] The oil O circulates in an oil passage 90 provided in the housing 6. The oil passage 90 is a path for supplying the oil O from the oil reservoir P to the motor 2. The oil passage 90 circulates the oil O to cool the motor 2.

[0041] The oil O is used to lubricate the reduction gear 4 and the differential gear 5. Furthermore, the oil O is used to cool the motor 2. The oil O is stored in the oil reservoir P at the bottom of the gear housing 62. To function as both a lubricating oil and a cooling oil, the oil O is preferably an oil of a relatively low viscosity, equivalent to automatic transmission fluid (ATF).

[0042] like Figure 1As shown, oil passage 90 is the path for oil O, which is directed from oil reservoir P on the lower side of motor 2 through motor 2 and back to oil reservoir P on the lower side of motor 2. Oil passage 90 includes a first oil passage 91 extending through the interior of motor 2 and a second oil passage 92 extending through the exterior of motor 2. Oil O cools motor 2 both internally and externally in first oil passage 91 and second oil passage 92. However, either first oil passage 91 or second oil passage 92 may be omitted.

[0043] In the first oil passage 91, oil O is lifted from the oil reservoir P by the pump unit 10 and guided into the interior of the rotor 20. The oil O is ejected from the rotor 20 toward the coil 31, cooling the stator 30. The oil O, having cooled the stator 30, then moves through the lower region of the motor housing 60 to the oil reservoir P of the gear housing 62.

[0044] In the second oil passage 92, the pump unit 10 draws oil O from the oil reservoir P. The oil O is drawn to the upper portion of the motor 2 and supplied to the motor 2 from the upper side. After cooling the motor 2, the oil O moves through the lower area of ​​the motor housing 60 to the oil reservoir P of the gear housing 62.

[0045] The housing 6 includes a cylindrical motor housing portion 60 extending along the motor axis J2; a gear housing portion 62 located axially on the other side of the motor housing portion 60; and a wall portion 63 that separates the motor housing portion 60 from the gear housing portion 62. In this embodiment, the housing 6 includes a first member 611 that forms the bottom and cylindrical portion of the motor housing portion 60 and the cylindrical portion of the gear housing portion 62; a second member 612 located axially on the other side of the gear housing portion 62; and the wall portion 63 that separates the motor housing portion 60 from the gear housing portion 62. The motor housing portion 60 houses the motor 2 inside. The gear housing portion 62 houses the transmission mechanism 3 inside. The wall portion 63 supports the bearings that rotatably support the shaft body 21 and the bearings that rotatably support the intermediate shaft body 45.

[0046] The stator 30 of the motor 2 is fixed inside the motor housing portion 60 .

[0047] The gear housing portion 62 has a plurality of vehicle body fixing portions (not shown) on a surface facing the other axial side. The drive device 1 is fixed to the vehicle frame via a mounting bracket or an insulating member by bolts fastened to the vehicle body fixing portions.

[0048] The inverter housing 8 extends forward (+X side) from the cylindrical portion of the motor housing 60. The inverter housing 8 is a rectangular box shape when viewed from the front. Figure 2As shown, when viewed from the second direction (X-axis direction), the inverter storage portion 8 overlaps with the motor axis J2 and the output axis J5. The inverter storage portion 8 has an opening portion 661 that opens in one direction. In this embodiment, the inverter storage portion 8 opens toward the front side of the vehicle. In addition, the opening portion 661 extends in the third direction. An inverter unit is installed in the opening portion 661 of the inverter storage portion 8. Since the inverter unit is installed in the opening portion 661 of the inverter storage portion 8, the opening portion 661 of the inverter storage portion 8 is closed and covered. The inverter cover portion that closes the opening portion 661 also extends in the third direction. In other words, the inverter unit extends in the third direction. The inverter unit is electrically connected to the coil 31 of the stator 30 inside the motor housing portion 60. Specifically, the inverter has an inverter-side connection portion (not shown) that is electrically connected to the motor 2. The inverter-side connection portion is connected to the motor-side connection portion 35, for example, via a busbar. The motor-side connection portion 35 has a portion located on the side opposite the output axis J5 relative to the motor axis J2 in the third direction (Z-axis direction). According to this embodiment, since the motor-side connection portion 35 is located near the end of the inverter housing 8 on one side (upper side) in the third direction, it is easier to ensure space for electronic components on the substrate within the inverter housing 8, thereby further reducing the thickness of the inverter housing 8.

[0049] In the housing 6, the inverter housing portion 8, the cylindrical portion of the motor housing portion 60, and the cylindrical portion of the gear housing portion 62 are part of a single die-cast component. In other words, the motor housing portion 60 and the inverter housing portion 8 are a single component. Therefore, compared with the case where the separate inverter housing portion 8 is fixed to the motor housing portion 60 using bolts or the like, vibration can be suppressed and noise can be reduced. In addition, since the inverter housing portion 8, the cylindrical portion of the motor housing portion 60, and the cylindrical portion of the gear housing portion 62 are integrated, the inverter housing portion 8 can be arranged near the motor 2, which can make the drive device 1 as a whole miniaturized.

[0050] Furthermore, according to this embodiment, the transmission mechanism 3 includes the reduction gear 4 and the differential gear 5. When viewed from the motor axis (i.e., the first direction), the transmission mechanism 3 overlaps with the inverter housing 8 and the differential gear 5. This allows the inverter and the differential gear 5 to be positioned closer together, enabling the overall miniaturization of the drive device 1.

[0051] Furthermore, according to this embodiment, when viewed from the first direction, the motor 2 and the differential device 5 overlap. This allows the motor 2 and the differential device 5 to be arranged close to each other, and the entire drive device 1 can be miniaturized.

[0052] Furthermore, according to this embodiment, when viewed from the first direction, the reduction gear 4 overlaps the inverter housing 8. This allows the reduction gear 4 and the inverter to be arranged close together, and the entire drive device 1 can be miniaturized.

[0053] Furthermore, according to the present embodiment, the inverter housing portion 8 is a rectangular box having an opening 661 opened in one direction, and overlaps a portion of the differential device 5 when viewed from a direction perpendicular to the first direction. Figure 3 As shown, a portion 81 of the inverter housing 8 that overlaps with a portion of the differential device 5 is located closer to the opening than other portions of the inverter housing 8. This allows the differential device 5 and the inverter to be arranged closer together, miniaturizing the entire drive device 1.

[0054] In addition, according to the present embodiment, the differential device 5 includes a ring gear 51 meshing with the third gear 43 of the reduction gear 4, and a differential case 52 having an outer diameter smaller than that of the ring gear 51. When viewed from a direction perpendicular to the first direction, the inverter housing 8 overlaps with the differential case 52. The portion 81 of the inverter housing 8 that overlaps with a portion of the differential device 5 is closer to the direction of the opening, i.e., to the opening portion 661, than other portions of the inverter housing 8. Thus, the differential device 5 and the inverter can be arranged closer together, and the drive device 1 as a whole can be miniaturized. In particular, according to this structure, the configuration space of the inverter, i.e., the shape of the inverter housing 8, is not rectangular, so that the portion for accommodating the differential case 52 enters a portion of the rectangle, thereby enabling the inverter and the differential device 5 to be arranged closer together. Thus, the drive device 1 as a whole can be miniaturized.

[0055] Furthermore, according to this embodiment, the inverter housing 8 has a narrowed first region at the location where it axially overlaps with the differential case 52 when viewed from a direction perpendicular to the motor axis (first direction). In other words, the distance between the inverter housing 8 and the opening 661 is shortened in the first region. This allows the inverter and differential gear 5 to be positioned closer together, thus miniaturizing the drive unit 1 as a whole.

[0056] Furthermore, according to this embodiment, a drive shaft 55 is included, to which rotation is transmitted from the differential device 5. The housing 6 includes a bearing support portion 56 at a location axially separated from the ring gear 51, which supports a bearing. The bearing rotatably supports the drive shaft 55, and the bearing support portion 56 is radially opposed to the inverter housing 8. Consequently, the wall portion forming the inverter housing 8 can also support the bearing supporting the drive shaft 55. Consequently, the inverter can be placed closer to the drive shaft 55, allowing the drive device 1 to be miniaturized as a whole.

[0057] <Second embodiment>

[0058] Next, refer to Figure 4 and Figure 5, a driving device 100 according to a second embodiment of the present invention will be described. In this embodiment, the same configurations as those in the previous embodiment are given the same names or the same reference numerals, and their description may be omitted.

[0059] In this embodiment, the vertical direction is defined based on the positional relationship when the drive device 100 is installed on a vehicle located on a horizontal road. The relative positional relationship related to the vertical direction only needs to be satisfied when the drive device 100 is installed on a vehicle located on a horizontal road.

[0060] In the drawings, an XYZ coordinate system is appropriately shown as a three-dimensional orthogonal coordinate system. In this embodiment, the Y-axis direction in which the motor axis J2 extends corresponds to the first direction, the Z-axis direction corresponds to the second direction, and the X-axis direction corresponds to the third direction.

[0061] like Figure 4 As shown, the drive device 100 of this embodiment includes a motor 2, a transmission mechanism 3, an inverter unit 7, a housing 6, oil O, an oil circuit (not shown), a heat exchanger 9, a pump (not shown), and a refrigerant flow path 11. The inverter unit 7 includes an inverter 12 and an inverter cover 13. In other words, the drive device 100 includes the inverter 12 and the inverter cover 13.

[0062] In this embodiment, the motor axis J2 and the output axis J5 are arranged in a substantially horizontal direction. Figure 4 As shown, when viewed from the first direction (Y-axis direction), the imaginary straight line VL passing through the motor axis J2 and the output axis J5 extends in the third direction, that is, the X-axis direction.

[0063] The intermediate axis J4 is located in the second direction (Z-axis direction) relative to the imaginary line VL. In this embodiment, the intermediate axis J4 is located above the imaginary line VL (the +Z side). When viewed from the first direction, the second gear 42, or pinion, overlaps with the inverter 12. Generally, the diameter of the pinion 42 is smaller than the diameters of the motor 2 and the ring gear 51. Therefore, by staggering the center of the pinion 42 (the intermediate axis J4) from the imaginary line VL in the second direction, the increase in the overall size of the drive device 100 in the second direction is suppressed. Furthermore, since the pinion 42 overlaps with the inverter 12 when viewed from the first direction, the drive device 100 as a whole can be made flatter in the second direction. Furthermore, when viewed from the first direction, the ring gear 51 overlaps with the inverter housing 8. That is, in this embodiment, the inverter housing 8 also overlaps with the differential device 5 when viewed from the first direction. Furthermore, the motor 2 overlaps with the differential device 5 when viewed from the first direction. Furthermore, the reduction gear 4 overlaps with the inverter housing 8 when viewed from the first direction.

[0064] The inverter 12 is located above the motor axis J2, in the second direction (Z-axis), and extends in the third direction (X-axis). The inverter 12 is a flat plate extending perpendicular to the second direction. The inverter 12 includes one or more substrates 12a, multiple electronic components 12b, and an inverter-side connection portion 14. The substrates 12a and electronic components 12b are secured to the inverter cover 13. In other words, the inverter 12 is secured to the inverter cover 13.

[0065] When viewed from the second direction, at least one substrate 12a overlaps the motor axis J2 and the output axis J5. According to this embodiment, since the substrate 12a overlaps the motor axis J2 and the output axis J5 when viewed from the second direction, a large substrate capable of mounting many electronic components can be used. For example, compared to stacking multiple small substrates, this embodiment can reduce costs.

[0066] The plurality of electronic components 12b include a switching element 12ba and a capacitor 12bb. That is, the inverter 12 includes a switching element 12ba and a capacitor 12bb. The switching element 12ba and the capacitor 12bb are fixed to the inverter cover 13. The switching element 12ba is, for example, an insulated gate bipolar transistor (IGBT). When viewed from the second direction, the capacitor 12bb overlaps with the output axis J5. According to this embodiment, by arranging the capacitor 12bb, which is an electronic component whose outer shape is easily increased, at a position overlapping with the output axis J5 when viewed from the second direction, the dead space above the output axis J5 can be utilized, and the drive device 100 can be made thinner. In addition, for example, sometimes, due to reasons such as vehicle layout, it is necessary to lower the upper end position of the portion of the inverter unit 7 that overlaps with the output axis J5 when viewed from the second direction. In such a case, if the capacitor 12bb is arranged at a position overlapping with the output axis J5 as described above, it is easy to make design changes. Furthermore, when making such a design change, for example, substrate 12a can be tilted so that it is located on the lower side (-Z side) as it moves toward the rear side (-X side). Furthermore, if capacitor 12bb is large, capacitor 12bb can be placed on the lower side of substrate 12a. In either case, the dead space above output axis J5 can be utilized, allowing drive device 100 to be thinner.

[0067] The inverter-side connection portion 14 is located at one end of the inverter 12 in the third direction and is electrically connected to the motor 2. In this embodiment, one end in the third direction is the front side (+X side), and the other end in the third direction is the rear side (-X side). The inverter-side connection portion 14 is connected to the motor-side connection portion 35, for example, via a busbar. In this embodiment, the motor-side connection portion 35 also has a portion located on the side opposite the output axis J5 relative to the motor axis J2 in the third direction (X-axis direction).

[0068] In the housing 6, at least a portion of the motor housing portion 60, at least a portion of the gear housing portion 62, and the inverter housing portion 8 are parts of a single member. At least a portion of the motor housing portion 60, at least a portion of the gear housing portion 62, and the inverter housing portion 8 are each part of a single die-cast component.

[0069] The inverter housing portion 8 is a bottomed cylindrical portion with an opening on the upper side. The inverter cover portion 8 extends in the third direction. In the present embodiment, when viewed from the second direction (Z-axis direction), the inverter housing portion 8 also overlaps with the motor axis J2 and the output axis J5. When viewed from the second direction, the end portion of the inverter housing portion 8 on the side facing the third direction overlaps with the end portion of the stator 30 on the side facing the third direction. According to the present embodiment, the inverter housing portion 8 extends to the outer end portion of the stator 30 on one side in the third direction. Therefore, the size of the inverter housing portion 8 in the third direction, that is, the size of the inverter housing portion 8 in the long side direction of the drive device 100, can be ensured to be larger, thereby enabling further thinning in the second direction.

[0070] The inverter housing 8 includes a peripheral wall portion 8a and a boundary wall portion 8b. The peripheral wall portion 8a is cylindrical, for example, a square cylinder, extending in the second direction. The boundary wall portion 8b is plate-shaped. The boundary wall portion 8b is located on the lower side of the inverter housing 8, i.e., on the imaginary line VL side, in the second direction. The boundary wall portion 8b separates the interior and exterior of the inverter housing 8 in the second direction. The position of the boundary wall portion 8b in the second direction varies at each position of the boundary wall portion 8b in the third direction. In this embodiment, the boundary wall portion 8b includes a pair of first plate portions 8ba and a second plate portion 8bb. The pair of first plate portions 8ba extend in a direction perpendicular to the second direction and have different positions in the second direction. The second plate portion 8bb connects the pair of first plate portions 8ba and extends in a direction perpendicular to the third direction. The second plate portion 8bb is not limited to the above-described structure. For example, it may extend circumferentially along the outer periphery of the motor 2 or may have other shapes. Alternatively, the boundary wall portion 8b may be referred to as a bottom wall portion.

[0071] In this embodiment, in the second direction, the distance between the boundary wall 8b and the output axis J5 is shorter than the distance between the boundary wall 8b and the motor axis J2. Specifically, the distance in the second direction between one of the pair of first plate portions 8ba located on one side of the third direction and the motor axis J2 is shorter than the distance in the second direction between the other first plate portion 8ba located on the other side of the pair of first plate portions 8ba and the output axis J5. That is, in the portion of the inverter housing 8 that overlaps with the output axis J5 when viewed from the second direction, the boundary wall 8b is positioned closer to the output axis J5, thereby ensuring a larger storage space for the components. Therefore, by arranging components of the inverter 12 that tend to increase in size, such as electronic components, in this portion of the storage space, dead space within the housing 6 can be effectively utilized, enabling the drive device 100 to be miniaturized.

[0072] The inverter cover 13 is in the shape of a flat plate extending in a direction perpendicular to the second direction. The inverter cover 13 extends in a third direction. The inverter cover 13 blocks the opening of the inverter storage portion 8. The inverter cover 13 is installed to the inverter storage portion 8 from a prescribed direction. In this embodiment, the direction in which the inverter cover 13 is installed to the inverter storage portion 8 is the second direction (Z-axis direction). That is, the prescribed direction is the second direction, specifically the vertical direction. As Figure 5 As shown, the inverter cover 13 is placed on the opening of the inverter housing 8, that is, in contact with the opening, and is fastened from the second direction by a screw member (not shown) or the like, thereby being fixed to the inverter housing 8. According to this embodiment, the inverter 12, specifically, the substrate 12a and the electronic components 12b are fixed to the inverter cover 13, so that heat from the motor 2 side is not easily transferred, and the cooling efficiency of the refrigerant flow path 11 described later on the various components of the inverter 12 is improved. The inverter housing 8 or the inverter cover 13 has a cylindrical member 15. The cylindrical member 15 extends in a predetermined direction, that is, the second direction. The structure of the cylindrical member 15 other than the above will be described later.

[0073] like Figure 4 and Figure 5As shown, the heat exchanger 9 is fixed to the housing 6. In the present embodiment, the heat exchanger 9 is located at a position on the side opposite to the motor axis J2 relative to the output axis J5 in the third direction. The heat exchanger 9 is fixed to the wall portion of the housing 6 facing the other side of the third direction. The heat exchanger 9 has a portion opposite to the inverter storage portion 8. In the present embodiment, the upper portion of the heat exchanger 9 is opposite to the peripheral wall portion 8a of the inverter storage portion 8. According to the present embodiment, the dead space that is not utilized in the existing drive device can be effectively utilized. Although not specifically shown in the figure, a portion of the oil circuit for oil O to circulate passes through the heat exchanger 9. That is, a portion of the oil circuit for oil O to flow is arranged at the heat exchanger 9.

[0074] Although not specifically shown in the figure, the pump of this embodiment is, for example, an electric oil pump. The pump is fixed to the housing 6. In this embodiment, the pump is located at a position on the side opposite to the motor axis J2 relative to the output axis J5 in the third direction. The pump is fixed to the wall portion of the housing 6 facing the other side of the third direction. The pump is arranged, for example, in the first direction with the heat exchanger 9. The pump sends the oil O sucked up from the oil reservoir P to the heat exchanger 9. The oil O that has undergone heat exchange with the cooling medium in the heat exchanger 9 is supplied to the motor 2, for example, from the upper side of the stator 30 and the inside of the shaft 21.

[0075] like Figure 4 As shown, the refrigerant flow path 11 passes through the inverter cover 13, a portion of the housing 6, and the heat exchanger 9. The cooling medium, cooled in the radiator (not shown), flows through the refrigerant flow path 11. The refrigerant flow path 11 cools the inverter unit 7 and the oil O. The refrigerant flow path 11 includes an electronic component cooling portion 11a, a heat exchange portion 11b, a cover-side opening 11c, a storage-side opening 11d, and a sealing bolt 11e.

[0076] The electronic component cooling section 11a is arranged in the inverter cover 13 and cools the electronic component 12b. The cooling medium flows from one side to the other side in the third direction in the electronic component cooling section 11a. The electronic component cooling section 11a includes a switching element cooling section 11aa and a capacitor cooling section 11ab. The switching element cooling section 11aa cools the switching element 12ba. The capacitor cooling section 11ab is arranged in the inverter cover 13 at a position on the other side of the third direction relative to the switching element cooling section 11aa and cools the capacitor 12bb. The capacitor cooling section 11ab is located on the downstream side of the refrigerant flow path 11 relative to the switching element cooling section 11aa. After cooling the switching element 12ba, the cooling medium flowing in the portion of the refrigerant flow path 11 located in the inverter cover 13 cools the capacitor 12bb and then cools the oil O in the heat exchanger 9. According to this embodiment, efficient cooling can be performed starting from the components that generate the most heat.

[0077] The heat exchange portion 11b is disposed in the heat exchanger 9 and exchanges heat between the oil O and the cooling medium. The heat exchange portion 11b is a portion of the refrigerant flow path 11 located in the heat exchanger 9. The oil O is cooled by the cooling medium flowing through the heat exchange portion 11b.

[0078] like Figure 5 As shown, the cover-side opening 11c is located in the portion of the refrigerant flow path 11 that connects the electronic component cooling section 11a and the heat exchange section 11b, and opens into the inverter cover 13. The cover-side opening 11c opens on the lower side of the inverter cover 13, i.e., on the side facing the inverter housing 8, and extends in the second direction. The cover-side opening 11c is, for example, in the shape of a circular hole.

[0079] The storage compartment-side opening 11d is located in the portion of the refrigerant flow path 11 that connects the electronic component cooling section 11a and the heat exchange section 11b and opens into the inverter storage section 8. The storage compartment-side opening 11d opens on the upper side of the inverter storage section 8, i.e., on the side facing the inverter cover 13, and extends in the second direction. In this embodiment, the storage compartment-side opening 11d opens on the upper end surface of the peripheral wall 8a and extends within the peripheral wall 8a in the second direction. The storage compartment-side opening 11d is, for example, in the shape of a circular hole.

[0080] When viewed from a predetermined direction, that is, in this embodiment, from the second direction (the Z-axis direction), the cover-side opening 11c and the storage-side opening 11d overlap and oppose each other. According to this embodiment, in the second direction in which the inverter cover 13 is mounted relative to the inverter storage unit 8, the cover-side opening 11c and the storage-side opening 11d oppose each other. Therefore, by assembling the inverter cover 13 to the housing 6, the portion of the refrigerant flow path 11 located in the inverter cover 13 is connected to the portion located in the inverter storage unit 8. Therefore, unlike conventional methods, which require a hose member or the like for connecting portions of the refrigerant flow path, according to this embodiment, the number of components is reduced, and the assembly process can be simplified.

[0081] The sealing bolt 11e blocks the end of the electronic component cooling section 11a on the other side of the third direction. The sealing bolt 11e is threadedly secured to the end of the electronic component cooling section 11a on the other side of the third direction. The provision of the sealing bolt 11e allows for a compact and simple design of the portion of the flow path that redirects the flow from the electronic component cooling section 11a to the lid-side opening 11c. Furthermore, removing the sealing bolt 11e provides easy access to the interior of the flow path of the electronic component cooling section 11a.

[0082] The cylindrical member 15 is tubular and centered on a central axis C. The central axis C of the cylindrical member 15 extends in a predetermined direction, i.e., the second direction. The cover-side opening 11c and the storage-side opening 11d are connected by the cylindrical member 15. According to this embodiment, the provision of the cylindrical member 15 suppresses leakage of the cooling medium at the connection between the cover-side opening 11c and the storage-side opening 11d in the refrigerant flow path 11.

[0083] The cylindrical member 15 includes a cylindrical body 15a, a flange portion 15b, a through-hole (not shown), a fixing member (not shown), and a plurality of O-rings 15c and 15d. The cylindrical body 15a extends in a predetermined direction, i.e., a second direction. The cylindrical body 15a is cylindrical, centered on the central axis C. The cylindrical body 15a includes a first insertion portion 15aa that is inserted into the lid-side opening 11c and a second insertion portion 15ab that is inserted into the housing-side opening 11d. In other words, the cylindrical member 15 includes the first insertion portion 15aa and the second insertion portion 15ab.

[0084] The flange portion 15b protrudes from the outer peripheral surface of the cylindrical body 15a. The flange portion 15b is in the shape of a plate extending in a direction perpendicular to the central axis C. The flange portion 15b is in the shape of an annular ring centered on the central axis C of the cylindrical member 15, and in the present embodiment is in the shape of a circular ring plate. Although not specifically shown in the figure, a through hole penetrates the flange portion 15b in a prescribed direction. A plurality of through holes are provided in the flange portion 15b at intervals around the central axis C. The fixing member is, for example, a threaded member. A plurality of fixing members are provided. The number of the fixing members is the same as the number of the through holes. The fixing member is inserted into the through hole and fixed to the inverter storage portion 8 or the inverter cover portion 13. That is, the cylindrical member 15 is fixed to the inverter storage portion 8 or the inverter cover portion 13. According to this embodiment, the cylindrical member 15 can be mounted to the inverter housing 8 or the inverter cover 13 with high precision, and leakage of the cooling medium from the connection portion between the cover-side opening 11 c and the housing-side opening 11 d can be further suppressed.

[0085] The O-rings 15c and 15d are annular and elastically deformable. In this embodiment, the O-rings 15c and 15d are provided as a pair. The pair of O-rings 15c and 15d is respectively attached to the first insertion portion 15aa and the second insertion portion 15ab, and contacts the inner circumference of the lid-side opening 11c or the inner circumference of the storage-side opening 11d.

[0086] While the embodiments of the present invention have been described above, the various structures and combinations thereof described in the embodiments are merely examples. Additions, omissions, substitutions, and other modifications may be made without departing from the spirit of the present invention. Furthermore, the present invention is not limited to the embodiments. For example, in the aforementioned embodiments, the heat exchanger 9 is described as cooling the oil O by a cooling medium flowing therein. However, in other words, the heat exchanger 9 may also be configured to heat the cooling medium by the oil O flowing therein.

[0087] Explanation of symbols

[0088] 1. 100 drive unit; 2 motor; 3 transmission mechanism; 4 reduction gear; 5 differential unit; 6 housing; 8 inverter storage unit; 8b boundary wall; 9 heat exchanger; 10 pump unit; 11 refrigerant flow path; 11a electronic component cooling unit; 11b heat exchange unit; 11c cover side opening; 11d storage unit side opening; 12 inverter; 12a substrate; 12b electronic component; 12ba switching element; 12bb capacitor; 13 inverter cover; 20 rotor; 21 shaft; 30 stator; 35 motor side connection unit; 41 first gear; 42 second gear; 51 ring gear; 52 differential case; 55 axle (drive shaft); 56 bearing support unit; 60 motor housing; 62 gear housing; 81 part; 90 oil passage; 661 opening; J2 motor axis; J4 intermediate axis; J5 output axis; O oil; VL imaginary straight line.

Claims

1. A driving device comprising: a motor having a rotor and a stator, wherein the rotor rotates about a motor axis extending in a first direction; an inverter that supplies power to the motor; a transmission mechanism that transmits the rotation output from the motor to an axle that rotates about an output axis; as well as The housing includes a motor housing portion, an inverter housing portion, and a gear housing portion, wherein the motor housing portion houses the motor, the inverter housing portion houses the inverter, and the gear housing portion houses the transmission mechanism. The motor includes a motor-side connection portion protruding from the stator and electrically connected to the inverter. The motor axis and the output axis extend parallel to each other, The inverter is located in a second direction perpendicular to the first direction relative to the motor axis and extends in a third direction perpendicular to the first direction and the second direction. When viewed from the first direction, an imaginary straight line passing through the motor axis and the output axis extends in the third direction, When viewed from the second direction, the inverter housing portion overlaps with the motor axis and the output axis. The inverter housing portion includes a boundary wall portion located at a boundary of the inverter housing portion on the side closer to the imaginary straight line in the second direction. In the second direction, the distance between the boundary wall and the output axis is smaller than the distance between the boundary wall and the motor axis. The motor-side connecting portion includes a portion located on the opposite side of the output axis relative to the motor axis in the third direction. The drive device includes an inverter cover portion, the inverter cover portion closing an opening of the inverter storage portion, The electronic components of the inverter are fixed to the inverter cover. The driving device further comprises: a heat exchanger fixed to the housing and provided with a portion of an oil passage through which oil flows; and a refrigerant flow path that passes through the inverter cover, a portion of the housing, and the heat exchanger and through which a cooling medium flows; The refrigerant flow path has: an electronic component cooling unit, the electronic component cooling unit being disposed on the inverter cover and cooling the electronic components; a heat exchange portion, the heat exchange portion being disposed in the heat exchanger and exchanging heat between the oil and the cooling medium; a cover-side opening portion, the cover-side opening portion being arranged at a portion of the refrigerant flow path connecting the electronic component cooling portion and the heat exchange portion and opening at the inverter cover portion; and a storage portion side opening portion, the storage portion side opening portion being arranged at a portion of the refrigerant flow path connecting the electronic component cooling portion and the heat exchange portion and opening at the inverter storage portion, The lid portion-side opening and the storage portion-side opening overlap and face each other when viewed from a predetermined direction.

2. The driving device according to claim 1, wherein: When viewed from the second direction, an end portion of the inverter housing portion on the side facing the third direction overlaps an end portion of the stator on the side facing the third direction.

3. The driving device according to claim 1, wherein: The inverter has one or more substrates. When viewed from the second direction, at least one of the substrates overlaps with the motor axis and the output axis.

4. The driving device according to claim 1, wherein: The inverter comprises a switching element and a capacitor. When viewed from the second direction, the capacitor overlaps with the output axis.

5. The driving device according to claim 1, wherein: The oil is included and is disposed in at least one of the motor housing portion and the gear housing portion.

6. The driving device according to claim 1, wherein: including the oil disposed in at least one of the motor housing portion and the gear housing portion, The heat exchanger is located on the opposite side of the motor axis relative to the output axis in the third direction.

7. The driving device according to claim 1, wherein: The transmission mechanism includes: a reduction gear having a first gear and a second gear, wherein the first gear is fixed to the shaft of the rotor, and the second gear is engaged with the first gear and rotates around the intermediate axis; and a differential device having a ring gear connected to the reduction gear and rotating about the output axis; The intermediate axis is located in the second direction relative to the imaginary straight line, When viewed from the first direction, the second gear overlaps with the inverter.

8. The driving device according to claim 1, wherein: The transmission mechanism includes a reduction gear that reduces the speed of the motor and a differential that transmits the reduced speed of the motor to the axle. When viewed from the first direction, the motor overlaps with the differential device.

9. The driving device according to claim 1, wherein: The transmission mechanism includes a reduction gear that reduces the speed of the motor and a differential that transmits the reduced speed of the motor to the axle. When viewed from the first direction, the reduction gear overlaps with the inverter housing portion.

10. The driving device according to any one of claims 1 to 9, wherein: In the housing, the motor housing portion and the inverter housing portion are a single member.

11. The driving device according to claim 10, wherein: The transmission mechanism includes a reduction gear that reduces the speed of the motor and a differential that transmits the reduced speed of the motor to the axle. The inverter housing is a rectangular box having an opening opened in one direction, and when viewed from a direction perpendicular to the first direction, the inverter housing overlaps a portion of the differential device. A portion of the inverter housing portion that overlaps with a portion of the differential device is located closer to the opening than other portions of the inverter housing portion.

12. The driving device according to claim 11, wherein: The differential device includes: a ring gear meshing with the gear of the reduction gear; and a differential case having an outer diameter smaller than that of the ring gear. The inverter housing overlaps with the differential case when viewed from a direction perpendicular to the first direction.

13. The driving device according to claim 12, wherein: The inverter housing portion includes a first region where a distance from the opening is shortened at a position overlapping with the differential case in the first direction when viewed from a direction perpendicular to the first direction.

14. The driving device according to any one of claims 11 to 13, wherein: The drive device includes a driving shaft to which rotation is transmitted from the differential device. The housing includes a bearing support portion for supporting a bearing at a portion spaced apart from the ring gear of the differential device in the first direction, wherein the bearing rotatably supports the driving shaft. The bearing support portion and the inverter housing portion are opposed to each other in the radial direction.

15. A driving device comprising: a motor having a rotor and a stator, wherein the rotor rotates about a motor axis extending in a first direction; an inverter that supplies power to the motor; a transmission mechanism that transmits the rotation output from the motor to an axle that rotates about an output axis; as well as The housing includes a motor housing portion, an inverter housing portion, and a gear housing portion, wherein the motor housing portion houses the motor, the inverter housing portion houses the inverter, and the gear housing portion houses the transmission mechanism. The motor includes a motor-side connection portion protruding from the stator and electrically connected to the inverter. The motor axis and the output axis extend parallel to each other, The inverter is located in a second direction perpendicular to the first direction relative to the motor axis and extends in a third direction perpendicular to the first direction and the second direction. When viewed from the first direction, an imaginary straight line passing through the motor axis and the output axis extends in the third direction, When viewed from the second direction, the inverter housing portion overlaps with the motor axis and the output axis. The inverter housing portion includes a boundary wall portion located at a boundary of the inverter housing portion on the side closer to the imaginary straight line in the second direction. In the second direction, the distance between the boundary wall and the output axis is smaller than the distance between the boundary wall and the motor axis. The motor-side connecting portion includes a portion located on the opposite side of the output axis relative to the motor axis in the third direction. The driving device comprises: a heat exchanger fixed to the housing and provided with a portion of an oil passage through which oil flows; as well as a refrigerant flow path, the refrigerant flow path passing through a portion of the shell and the heat exchanger and allowing a cooling medium to flow; The refrigerant flow path includes a heat exchange portion, which is disposed in the heat exchanger and exchanges heat between the oil and the cooling medium. The heat exchanger is located on the opposite side of the motor axis relative to the output axis in the third direction.

16. The driving device according to claim 15, wherein: When viewed from the second direction, an end portion of the inverter housing portion on the side facing the third direction overlaps an end portion of the stator on the side facing the third direction.

17. The driving device according to claim 15, wherein: The inverter has one or more substrates. When viewed from the second direction, at least one of the substrates overlaps with the motor axis and the output axis.

18. The driving device according to claim 15, wherein The inverter comprises a switching element and a capacitor. When viewed from the second direction, the capacitor overlaps with the output axis.

19. The driving device according to claim 15, wherein: The drive device includes an inverter cover portion, the inverter cover portion closing an opening of the inverter storage portion, The electronic components of the inverter are fixed to the inverter cover.

20. The driving device according to claim 15, wherein The oil is included and is disposed in at least one of the motor housing portion and the gear housing portion.

21. The driving device according to claim 15, wherein The transmission mechanism includes: a reduction gear having a first gear and a second gear, wherein the first gear is fixed to the shaft of the rotor, and the second gear is engaged with the first gear and rotates around the intermediate axis; and a differential device having a ring gear connected to the reduction gear and rotating about the output axis; The intermediate axis is located in the second direction relative to the imaginary straight line, When viewed from the first direction, the second gear overlaps with the inverter.

22. The driving device according to claim 15, wherein: The transmission mechanism includes a reduction gear that reduces the speed of the motor and a differential that transmits the reduced speed of the motor to the axle. When viewed from the first direction, the motor overlaps with the differential device.

23. The driving device according to claim 15, wherein: The transmission mechanism includes a reduction gear that reduces the speed of the motor and a differential that transmits the reduced speed of the motor to the axle. When viewed from the first direction, the reduction gear overlaps with the inverter housing portion.

24. The driving device according to any one of claims 15 to 23, wherein: In the housing, the motor housing portion and the inverter housing portion are a single member.

25. The driving device according to claim 24, wherein: The transmission mechanism includes a reduction gear that reduces the speed of the motor and a differential that transmits the reduced speed of the motor to the axle. The inverter housing is a rectangular box having an opening opened in one direction, and when viewed from a direction perpendicular to the first direction, the inverter housing overlaps a portion of the differential device. A portion of the inverter housing portion that overlaps with a portion of the differential device is located closer to the opening than other portions of the inverter housing portion.

26. The driving device according to claim 25, wherein: The differential device includes: a ring gear meshing with the gear of the reduction gear; and a differential case having an outer diameter smaller than that of the ring gear. The inverter housing overlaps with the differential case when viewed from a direction perpendicular to the first direction.

27. The driving device according to claim 26, wherein: The inverter housing portion includes a first region where a distance from the opening is shortened at a position overlapping with the differential case in the first direction when viewed from a direction perpendicular to the first direction.

28. The driving device according to any one of claims 25 to 27, wherein: The drive device includes a driving shaft to which rotation is transmitted from the differential device. The housing includes a bearing support portion for supporting a bearing at a portion spaced apart from the ring gear of the differential device in the first direction, wherein the bearing rotatably supports the driving shaft. The bearing support portion and the inverter housing portion are opposed to each other in the radial direction.

29. A driving device comprising: a motor having a rotor and a stator, wherein the rotor rotates about a motor axis extending in a first direction; an inverter that supplies power to the motor; a transmission mechanism that transmits the rotation output from the motor to an axle that rotates about an output axis; as well as The housing includes a motor housing portion, an inverter housing portion, and a gear housing portion, wherein the motor housing portion houses the motor, the inverter housing portion houses the inverter, and the gear housing portion houses the transmission mechanism. The motor includes a motor-side connection portion protruding from the stator and electrically connected to the inverter. The motor axis and the output axis extend parallel to each other, The inverter is located in a second direction perpendicular to the first direction relative to the motor axis and extends in a third direction perpendicular to the first direction and the second direction. When viewed from the first direction, an imaginary straight line passing through the motor axis and the output axis extends in the third direction, When viewed from the second direction, the inverter housing portion overlaps with the motor axis and the output axis. The inverter housing portion includes a boundary wall portion located at a boundary of the inverter housing portion on the side closer to the imaginary straight line in the second direction. In the second direction, the distance between the boundary wall and the output axis is smaller than the distance between the boundary wall and the motor axis. The motor-side connecting portion includes a portion located on the opposite side of the output axis relative to the motor axis in the third direction. The driving device comprises: a heat exchanger fixed to the housing and provided with a portion of an oil passage through which oil flows; as well as a refrigerant flow path, the refrigerant flow path passing through a portion of the shell and the heat exchanger and allowing a cooling medium to flow; The heat exchanger has a portion facing the inverter housing portion in a direction perpendicular to the first direction and in which the inverter extends.

30. A driving device comprising: a motor having a rotor rotatable about a motor axis extending in a first direction; an inverter that controls current supplied to the motor; a transmission mechanism for transmitting power from the motor to the axle; as well as a housing for housing the motor, the inverter, and the transmission mechanism; The housing includes an inverter receiving portion for receiving the inverter. The transmission mechanism includes a reduction gear that reduces the speed of the motor and a differential that transmits the reduced speed of the motor to the axle. When viewed from the first direction, the inverter housing overlaps with the differential device. The inverter housing portion overlaps with at least a portion of the differential device in a second direction perpendicular to the first direction.

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