Drive unit

Abstract

This drive device is provided with a motor, an inverter, a transmission mechanism, and a housing. The motor has a motor side connection portion projecting from the stator and electrically connected to the inverter. A motor axis and an output axis extend in parallel with each other. The inverter is located in a second direction orthogonal to a first direction with respect to the motor axis and extends in a third direction orthogonal to the first and second directions. When viewed from the first direction, a virtual line passing through the motor axis and the output axis extends in the third direction. When viewed from the second direction, an inverter housing portion overlaps with the motor axis and the output axis. The inverter housing portion has a boundary wall portion in the second direction, said boundary wall portion being located at the virtual line side boundary of the inverter housing portion. The distance between the boundary wall portion and the output axis is smaller in the second direction than the distance between the boundary wall portion and the motor axis. In the third direction, the motor side connection portion has a portion located further than the motor axis on the opposite side to the output axis.

Description

[Technical Field]

[0001] This application claims priority from Japanese Patent Application No. 2019-227659, filed December 17, 2019, the contents of which are incorporated herein by reference. [Background technology]

[0002] BACKGROUND ART Conventionally, a drive device in which a motor, an inverter, and a transmission mechanism are integrated has been known. For example, Patent Document 1 discloses a drive device in which a motor, an inverter, and a transmission mechanism are integrated. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] International Publication No. 2019 / 076696 Summary of the Invention [Problem to be solved by the invention]

[0004] When the drive device is used as a drive device for a vehicle, it is required to reduce the size of the motor, inverter, and transmission mechanism.

[0005] An object of the present invention is to provide a drive device that can be made smaller. [Means for solving the problem]

[0006] One embodiment of a drive device of the present invention includes a motor having a rotor and a stator that rotates about a motor shaft extending in a first direction, an inverter that supplies power to the motor, a transmission mechanism that transmits rotation output from the motor to an axle that rotates about an output shaft, and a housing having a motor housing portion that accommodates the motor, an inverter accommodating portion that accommodates the inverter, and a gear housing portion that accommodates the transmission mechanism. The motor has a motor-side connection portion that protrudes from the stator and is electrically connected to the inverter. The motor shaft and the output shaft extend parallel to each other. The inverter is located in a second direction that is perpendicular to the first direction with respect to the motor shaft and extends in a third direction that is perpendicular to the first and second directions. When viewed from the first direction, an imaginary line passing through the motor shaft and the output shaft extends in the third direction. When viewed from the second direction, the inverter accommodating portion overlaps with the motor shaft and the output shaft. The inverter accommodating portion has a boundary wall portion that is located at the boundary of the inverter accommodating portion on the side of the imaginary line in the second direction. In the second direction, the distance between the boundary wall portion and the output shaft is smaller than the distance between the boundary wall portion and the motor shaft. The motor-side connection portion has a portion located on the opposite side of the motor shaft from the output shaft in the third direction.

[0007] One aspect of the drive device of the present invention includes a motor having a rotor rotatable around a motor shaft extending in a first direction, an inverter that controls the current supplied to the motor, a transmission mechanism that transmits power from the motor to an axle, and a housing that accommodates the motor, the inverter, and the transmission mechanism. The housing includes an inverter accommodating section that accommodates the inverter. The transmission mechanism includes a reduction gear that reduces the rotation of the motor and a differential gear that transmits the rotation of the motor reduced by the reduction gear to the axle. When viewed from the first direction, the inverter accommodating section and the differential gear overlap. [Effects of the Invention]

[0008] According to one aspect of the present invention, it is possible to reduce the size of a drive device that integrates a motor, an inverter, and a transmission mechanism. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a conceptual diagram of a drive device according to a first embodiment. [Figure 2] FIG. 2 is a view of the motor, transmission mechanism, and inverter of the drive device of the first embodiment as viewed from the axial direction. [Figure 3] FIG. 3 is a perspective view of the motor, the transmission mechanism, and the inverter in the drive device of the first embodiment. [Figure 4] FIG. 4 is a side view showing the drive device of the second embodiment. [Figure 5] FIG. 5 is an enlarged perspective view of the V portion of FIG. DETAILED DESCRIPTION OF THE INVENTION

[0010] First Embodiment A drive unit 1 according to a first embodiment of the present invention will be described with reference to FIGS. 1 to 3. In the following description, the direction of gravity is defined based on the positional relationship when the drive unit 1 is mounted on a vehicle positioned on a horizontal road surface. The drawings also show an XYZ coordinate system as a three-dimensional Cartesian coordinate system as appropriate. In the XYZ coordinate system, the Z axis direction indicates the vertical direction (i.e., the up-down direction), the +Z direction is the upper side (opposite the direction of gravity), and the -Z direction is the lower side (direction of gravity). The X axis direction is perpendicular to the Z axis direction and indicates the front-to-rear direction of the vehicle on which the drive unit 1 is mounted, with the +X direction being the front of the vehicle and the -X direction being the rear of the vehicle.

[0011] However, it is also possible that the +X direction is the rear of the vehicle and the -X direction is the front of the vehicle. The Y axis direction is perpendicular to both the X axis direction and the Z axis direction and indicates the width direction (left-right direction) of the vehicle, with the +Y direction being the left side of the vehicle and the -Y direction being the right side of the vehicle. However, when the +X direction is the rear of the vehicle, it is also possible that the +Y direction is the right side of the vehicle and the -Y direction is the left side of the vehicle. In other words, regardless of the direction of the X axis, the +Y direction is simply one side of the left-right direction of the vehicle, and the -Y direction is the other side of the left-right direction of the vehicle.

[0012] In the following description, unless otherwise specified, the direction parallel to the motor shaft J2 of the motor 2 (the Y-axis direction) is simply referred to as the "axial direction," the radial direction centered on the motor shaft J2 is simply referred to as the "radial direction," and the circumferential direction centered on the motor shaft J2, i.e., around the axis of the motor shaft J2, is simply referred to as the "circumferential direction." However, the above "parallel direction" also includes a direction that is approximately parallel. Specifically, in this embodiment, "parallel" refers to an angle between a pair of elements that translate (extend) in approximately the same direction, i.e., an angle (inclination angle) at which one element is inclined relative to the other, being 30° or less. 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 shaft J2 extends, i.e., 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.

[0013] The drive device 1 of this embodiment is mounted on a vehicle powered by a motor, 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 thereof.

[0014] As shown in FIG. 1, the drive device 1 includes a motor 2, a transmission mechanism 3, a housing 6, oil O accommodated in the housing 6, and an inverter unit (inverter). The inverter unit is accommodated in an inverter accommodating section 8 of the housing 6. In this embodiment, the inverter unit includes an inverter and an inverter lid. That is, the drive device 1 includes an inverter and an inverter lid. The inverter lid closes the opening of the inverter accommodating section 8. The inverter lid is fixed to an opening 661 of the inverter accommodating section 8, which will be described later, with a screw member or the like.

[0015] The motor 2 includes a rotor 20 that rotates around a motor axis J2 that extends horizontally, a stator 30 located radially outward of the rotor 20, and a motor-side connection portion 35. The motor axis J2 extends in a first direction. The housing 6 includes a motor housing portion 60 that accommodates the motor 2, a gear housing portion 62 that accommodates the transmission mechanism 3, a wall portion 63 that separates the motor housing portion 60 from the gear housing portion 62, and an inverter accommodating portion 8 that accommodates the inverter.

[0016] The motor 2 is an inner rotor type motor in which the rotor 20 is disposed inside the stator 30. The rotor 20 has a shaft 21, a rotor core 24, and a rotor magnet (not shown).

[0017] The shaft 21 is centered on a motor axis J2 that extends horizontally and in the width direction of the vehicle. The shaft 21 is a hollow shaft having a hollow portion 22 therein. The shaft 21 protrudes from the motor housing portion 60 into the gear housing portion 62. The end of the shaft 21 that protrudes into the gear housing portion 62 is connected to the transmission mechanism 3. Specifically, the shaft 21 is connected to the first gear 41.

[0018] 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) interposed between the stator core 32 and the coil 31. The stator 30 is held in a motor housing portion 60. In this embodiment, the stator 30 is held in the motor housing portion 60 via a stator support member 33. Grooves are provided on the inner or outer peripheral surface of the stator support member 33, forming a water channel between the stator 30 or the motor housing portion 60. Cooling water is supplied to the water channel from a radiator (not shown), thereby cooling the stator 30. The coil 31 is connected to an inverter unit.

[0019] As shown in Fig. 2, the motor-side connection portion 35 protrudes from the stator 30. The motor-side connection portion 35 is a wiring member, such as a bus bar, that is connected to the coil 31. The motor-side connection portion 35 may include a plurality of conductors that extend from the coil 31 and are 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.

[0020] As shown in FIG. 1, the transmission mechanism 3 transmits the rotation output from the motor 2 to the axle 55, which rotates around the output shaft J5. In other words, the transmission mechanism 3 transmits the power of the motor 2 to the axle 55. The motor shaft J2 and the output shaft J5 extend parallel to each other. In this embodiment, the motor shaft J2 and the output shaft J5 are arranged side by side in a substantially vertical direction. As shown in FIG. 2, when viewed from the first direction (Y-axis direction), an imaginary line VL passing through the motor shaft J2 and the output shaft J5 extends in the Z-axis direction, which is the third direction. In other words, when viewed from the first direction, the imaginary line VL extends parallel to the third direction.

[0021] As shown in FIG. 1, the transmission mechanism 3 is housed in the gear housing portion 62. The transmission mechanism 3 is connected to the shaft 21 on the other axial side of the motor shaft J2. The transmission mechanism 3 has a reduction gear 4 that reduces the rotation of the motor 2, and a differential gear 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 gear 5 via the reduction gear 4.

[0022] 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 coupled to the shaft 21 of the motor 2. The first gear 41 is fixed to the shaft 21 of the rotor 20. Determined The intermediate shaft 45 extends along an intermediate shaft J4 that is parallel to the motor shaft 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 via the intermediate shaft 45. The second gear 42, the intermediate shaft 45, and the third gear 43 rotate about the intermediate shaft J4. As shown in FIG. 2, the intermediate shaft J4 is located in the second direction (X-axis direction) with respect to the imaginary line VL. That is, the intermediate shaft J4 is disposed away from the imaginary line VL in the second direction. In this embodiment, the intermediate shaft J4 is located on the front side (+X side) of the imaginary line VL.

[0023] The second gear 42 is a counter gear. The second gear 42 meshes with the first gear 41. As shown in Fig. 1, the third gear 43 meshes with a ring gear 51 of the differential device 5. The intermediate shaft 45 is connected to the pump unit 10, which will be described later.

[0024] Torque output from the motor 2 is transmitted to the ring gear 51 of the differential device 5 via the shaft 21 of the motor 2, the first gear 41, the second gear 42, the intermediate shaft 45, and the third gear 43. The gear ratio of each gear and the number of gears can be changed according to the required reduction ratio. The reduction device 4 is a parallel-shaft gear type reducer in which the axes of the gears are arranged in parallel.

[0025] The differential 5 transmits the torque output from the motor 2 to the axles 55 of the vehicle. 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 the left and right wheels. The differential 5 has a ring gear 51 that meshes with the third gear 43 of the reduction gear 4, a differential case 52, as well as a pinion gear, a pinion shaft, a side gear, and the like, none of which are shown. The ring gear 51 is connected to the reduction gear 4 and rotates around the output shaft J5.

[0026] The oil O is disposed in at least one of the motor housing portion 60 and the gear housing portion 62. An oil sump P in which the oil O accumulates is provided in a lower region within the gear housing portion 62. In this embodiment, the bottom of the motor housing portion 60 is located above the bottom of the gear housing portion 62. With this configuration, the oil O after cooling the motor 2 can be easily collected from the lower region of the motor housing portion 60 to the oil sump P in the gear housing portion 62.

[0027] A portion of the differential gear 5 is immersed in the oil sump P. The oil O that collects in the oil sump P is scooped up by the operation of the differential gear 5. Some of the oil O that is scooped up is supplied into the shaft 21. However, it does not have to be supplied into the shaft 21. Another portion of the oil O is diffused into the gear housing portion 62 and supplied to each gear of the reduction gear 4 and the differential gear 5. The oil O that has been used to lubricate the reduction gear 4 and the differential gear 5 drips down and is collected in the oil sump P located below the gear housing portion 62.

[0028] The inverter unit controls the current supplied to the motor 2. The inverter unit is fixed to the housing 6 and accommodated in the inverter accommodating section 8. The inverter supplies power to the motor 2. As shown in FIG. 2, the inverter is located in front 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, the inverter extends in the third direction, i.e., the longitudinal direction of the drive device 1 in which the motor 2 and the transmission mechanism 3 are aligned, so that the dimension of the inverter unit in the second direction can be kept small, thereby enabling a thinner device.

[0029] As shown in FIG. 1, the pump unit 10 is an oil pump driven by a motor 2 via a first gear 41, a second gear 42, and an intermediate shaft 45. The pump unit 10 sucks up oil O from an oil reservoir P. The motor 2 rotates a pump mechanism of the pump unit 10. do. In the drive unit 1, the rotation axis J6 of the pump mechanism is parallel to the motor axis J2. Because the pump unit 10 can be driven by the motor 2, oil O can be pumped up without providing an additional accessory such as a pump drive motor. In addition, because the pump unit 10 can be driven without changing the rotation direction of the intermediate shaft 45 using a bevel gear or the like, the dimensions of the drive unit 1 can be reduced.

[0030] 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 and cools the motor 2.

[0031] The oil O is used to lubricate the reduction gear 4 and the differential gear 5. The oil O is also used to cool the motor 2. The oil O is collected in an oil reservoir P below the gear housing portion 62. Since the oil O functions as both a lubricating oil and a cooling oil, it is preferable to use an oil equivalent to a low-viscosity lubricating oil for automatic transmissions (ATF: Automatic Transmission Fluid).

[0032] As shown in FIG. 1 , oil passage 90 is a path for oil O that runs from oil sump P below motor 2, through motor 2, and back to oil sump P below motor 2. Oil passage 90 has a first oil passage 91 that runs through the interior of motor 2, and a second oil passage 92 that runs through the exterior of motor 2. Oil O cools motor 2 from the inside and outside in first oil passage 91 and second oil passage 92. However, either first oil passage 91 or second oil passage 92 may be omitted.

[0033] In the first oil passage 91, the oil O is scooped up from the oil reservoir P by the pump unit 10 and guided into the rotor 20. The oil O is sprayed from the rotor 20 toward the coil 31 and cools the stator 30. After cooling the stator 30, the oil O moves to the oil reservoir P in the gear housing unit 62 via the lower region of the motor housing unit 60.

[0034] In the second oil passage 92, the oil O is pumped up from the oil reservoir P by the pump unit 10. The oil O is pumped up to the top of the motor 2 and supplied to the motor 2 from the upper side of the motor 2. After cooling the motor 2, the oil O moves to the oil reservoir P in the gear housing unit 62 via the lower region of the motor housing unit 60.

[0035] The housing 6 has a cylindrical motor housing portion 60 extending along the motor axis J2, a gear housing portion 62 located on the other axial 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 has a bottom and cylindrical portion of the motor housing portion 60, a first member 611 that forms the cylindrical portion of the gear housing portion 62, a second member 612 located on the other axial 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 accommodates the motor 2 therein. The gear housing portion 62 accommodates the transmission mechanism 3 therein. The wall portion 63 supports a bearing that rotatably supports the shaft 21 and a bearing that rotatably supports the intermediate shaft 45.

[0036] The stator 30 of the motor 2 is fixed inside the motor housing portion 60.

[0037] The gear housing 62 has a plurality of vehicle body fixing portions (not shown) on a surface facing the other axial direction. The drive unit 1 is fixed to the vehicle frame via a mount bracket or an insulator by bolts fastened to the vehicle body fixing portions.

[0038] The inverter accommodating section 8 extends forward (towards the +X side) from the cylindrical section of the motor housing section 60. The inverter accommodating section 8 has a rectangular box shape when viewed from the front. As shown in FIG. Member The inverter accommodating portion 8 overlaps with the motor shaft J2 and the output shaft J5 when viewed from the second direction (X-axis direction). The inverter accommodating portion 8 has an opening 661 that opens in one direction. In this embodiment, the inverter accommodating portion 8 opens toward the front of the vehicle. The opening 661 also extends in the third direction. An inverter unit is attached to the opening 661 of the inverter accommodating portion 8. Attaching the inverter unit to the opening 661 of the inverter accommodating portion 8 closes and covers the opening 661 of the inverter accommodating portion 8. The inverter cover that covers the opening 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 via, for example, a bus bar or the like. The motor-side connection portion 35 has a portion located on the opposite side of the output shaft J5 from the motor axis J2 in the third direction (Z-axis direction). According to this embodiment, the motor-side connection portion 35 is disposed close to the end of the inverter accommodating portion 8 on one side (upper side) in the third direction, making it easier to ensure space for arranging electronic components and the like on the board within the inverter accommodating portion 8, thereby enabling a further slimming down.

[0039] In the housing 6, the inverter accommodating 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 accommodating portion 8 are a single member. This makes it possible to suppress vibration and reduce noise compared to when a separate inverter accommodating portion 8 is fixed to the motor housing portion 60 using bolts or the like. Furthermore, because the inverter accommodating 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 accommodating portion 8 can be located near the motor 2, allowing the entire drive device 1 to be made smaller.

[0040] Furthermore, according to this embodiment, the transmission mechanism 3 has the reduction gear 4 and the differential gear 5, and when viewed from the motor axial direction, i.e., the first direction, the inverter accommodating section 8 and the differential gear 5 overlap. This allows the inverter and the differential gear 5 to be disposed close to each other, thereby making it possible to reduce the size of the entire drive unit 1.

[0041] 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 disposed close to each other, and the overall size of the drive device 1 can be reduced.

[0042] Furthermore, according to this embodiment, when viewed from the first direction, the reduction gear 4 and the inverter accommodating section 8 overlap. This allows the reduction gear 4 and the inverter to be disposed close to each other, and the overall size of the drive device 1 can be reduced.

[0043] Furthermore, according to this embodiment, the inverter accommodating section 8 is a rectangular box having an opening 661 that opens in one direction, and overlaps with a portion of the differential device 5 when viewed from a direction perpendicular to the first direction. As shown in FIG. 3 , the portion 81 of the inverter accommodating section 8 that overlaps with a portion of the differential device 5 is located closer to the opening than other portions of the inverter accommodating section 8. This allows the differential device 5 and the inverter to be disposed close to each other, thereby enabling the overall size of the drive device 1 to be reduced.

[0044] Furthermore, according to this embodiment, the differential device 5 includes a ring gear 51 that meshes with the third gear 43 of the reduction gear 4, and a differential case 52 that has an outer diameter smaller than that of the ring gear 51. The inverter accommodating section 8 overlaps with the differential case 52 when viewed from a direction perpendicular to the first direction. A portion 81 of the inverter accommodating section 8 that overlaps with part of the differential device 5 is located closer to the opening than other portions of the inverter accommodating section 8, i.e., closer to the opening 661. This allows the differential device 5 and the inverter to be disposed closer to each other, and the entire drive unit 1 can be made more compact. In particular, with this configuration, the shape of the inverter accommodating section 8, which is the inverter arrangement space, is not rectangular, and the portion for accommodating the differential case 52 extends into part of the rectangle, allowing the inverter and the differential device 5 to be disposed even closer to each other. This allows the entire drive unit 1 to be made more compact. Can do.

[0045] Furthermore, according to this embodiment, the inverter accommodating section 8 has a first region that narrows at a position where it axially overlaps with the differential case 52 when viewed from a direction perpendicular to the motor shaft (first direction). In other words, the distance from the opening 661 to the inverter accommodating section 8 is shorter in the first region. This allows the inverter and the differential device 5 to be arranged even closer to each other. This allows the entire drive device 1 to be made smaller.

[0046] Furthermore, according to this embodiment, the housing 6 includes a drive shaft 55 to which rotation is transmitted from the differential device 5, and the housing 6 has a bearing support portion 56 that supports a bearing that rotatably supports the drive shaft 55 at a location axially spaced from the ring gear 51, and the bearing support portion 56 faces the inverter accommodating portion 8 in the radial direction. This allows the wall that constitutes the inverter accommodating portion 8 to also support the bearing that supports the drive shaft 55. Therefore, the inverter can be placed close to the drive shaft 55, and the entire drive unit 1 can be made smaller.

[0047] Second Embodiment Next, a drive device 100 according to a second embodiment of the present invention will be described with reference to Figures 4 and 5. In this embodiment, the same components as those in the previous embodiment will be given the same names or reference numerals, and their description may be omitted.

[0048] In this embodiment, the vertical direction is defined based on the positional relationship when the drive unit 100 is mounted on a vehicle positioned on a horizontal road surface. The relative positional relationship in the vertical direction only needs to be satisfied when the drive unit 100 is mounted on a vehicle positioned on a horizontal road surface.

[0049] In the drawings, an XYZ coordinate system is shown as a three-dimensional Cartesian coordinate system as appropriate. In this embodiment, the direction in which the motor shaft J2 extends, i.e., the Y-axis direction, corresponds to the first direction, the Z-axis direction corresponds to the second direction, and the X-axis direction corresponds to the third direction.

[0050] 4, 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 passage (not shown), a heat exchanger 9, a pump (not shown), and a refrigerant passage 11. The inverter unit 7 includes an inverter 12 and an inverter lid 13. That is, the drive device 100 includes the inverter 12 and the inverter lid 13.

[0051] In this embodiment, the motor shaft J2 and the output shaft J5 are arranged side by side in a substantially horizontal direction. As shown in Fig. 4, when viewed from the first direction (Y-axis direction), a virtual line VL passing through the motor shaft J2 and the output shaft J5 extends in the X-axis direction, which is the third direction.

[0052] The intermediate shaft J4 is located in the second direction (Z-axis direction) with respect to the imaginary line VL. In this embodiment, the intermediate shaft J4 is located above (on the +Z side of) the imaginary line VL. When viewed from the first direction, the second gear 42, i.e., the counter gear, and the inverter 12 overlap. Generally, the counter gear 42 has a smaller diameter than the motor 2 and the ring gear 51. Therefore, by displacing the center of the counter gear 42 (the intermediate shaft J4) from the imaginary line VL in the second direction, the bulkiness of the entire driving device 100 in the second direction can be reduced. Furthermore, by overlapping the counter gear 42 and the inverter 12 when viewed from the first direction, the entire driving device 100 can be made flatter in the second direction. Furthermore, when viewed from the first direction, the ring gear 51 overlaps with the inverter accommodating section 8. That is, in this embodiment, too, when viewed from the first direction, the inverter accommodating section 8 and the differential device 5 overlap. Furthermore, when viewed from the first direction, the motor 2 and the differential device 5 overlap. Furthermore, when viewed from the first direction, the reduction gear device 4 and the inverter accommodating portion 8 overlap each other.

[0053] The inverter 12 is located above the motor shaft J2, i.e., in the second direction (Z-axis direction), and extends in the third direction (X-axis direction). The inverter 12 has a flat plate shape that extends in a direction perpendicular to the second direction. The inverter 12 has one or more circuit boards 12a, multiple electronic components 12b, and an inverter-side connection portion 14. The circuit boards 12a and the electronic components 12b are fixed to the inverter lid 13. That is, the inverter 12 is fixed to the inverter lid 13.

[0054] At least one of the substrates 12a overlaps with the motor shaft J2 and the output shaft J5 when viewed from the second direction. According to this embodiment, since the substrate 12a overlaps with the motor shaft J2 and the output shaft J5 when viewed from the second direction, a large substrate capable of mounting many electronic components can be used. This embodiment can reduce costs compared to, for example, stacking multiple small substrates.

[0055] The multiple electronic components 12b include a switching element 12ba and a capacitor 12bb. That is, the inverter 12 includes the switching element 12ba and the capacitor 12bb. The switching element 12ba and the capacitor 12bb are fixed to the inverter lid 13. The switching element 12ba is, for example, an insulated gate bipolar transistor (IGBT). The capacitor 12bb overlaps with the output shaft J5 when viewed from the second direction. According to this embodiment, the capacitor 12bb, which tends to be bulky as an electronic component, is positioned so as to overlap with the output shaft J5 when viewed from the second direction. This allows for the utilization of dead space above the output shaft J5, thereby enabling the drive device 100 to be made thinner. Furthermore, for example, due to vehicle layout reasons, it may be necessary to lower the upper end position of the portion of the inverter unit 7 that overlaps with the output shaft J5 when viewed from the second direction. Even in such a case, if capacitor 12bb is positioned so as to overlap with output shaft J5 as described above, design changes can be easily made. When making such design changes, for example, substrate 12a may be tilted so that it is positioned lower (toward the -Z side) as it approaches the rear (toward the -X side). Furthermore, if capacitor 12bb is large, capacitor 12bb can also be positioned below substrate 12a. In either case, the dead space above output shaft J5 can be utilized, allowing for a thinner drive unit 100.

[0056] The inverter-side connection part 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 side in the third direction is the front side (+X side), and the other side in the third direction is the rear side (-X side). The inverter-side connection part 14 is connected to the motor-side connection part 35 via, for example, a bus bar. In this embodiment, the motor-side connection part 35 also has a portion located on the opposite side of the motor shaft J2 from the output shaft J5 in the third direction (X-axis direction).

[0057] 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 accommodating portion 8 are part 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 accommodating portion 8 each constitute part of a single die-cast part.

[0058] The inverter accommodating section 8 is cylindrical and has a bottom that opens upward. The inverter accommodating section 8 extends in the third direction. In this embodiment, too, the inverter accommodating section 8 overlaps with the motor shaft J2 and the output shaft J5 when viewed from the second direction (Z-axis direction). One end of the inverter accommodating section 8 on one side in the third direction overlaps with one end of the stator 30 on one side in the third direction when viewed from the second direction. According to this embodiment, since the inverter accommodating section 8 extends to the outer end of the stator 30 on one side in the third direction, it is possible to ensure a large dimension of the inverter accommodating section 8 in the third direction, i.e., the dimension of the inverter accommodating section 8 in the longitudinal direction of the drive device 100. R This makes it possible to further reduce the thickness in two directions.

[0059] The inverter accommodating section 8 has a peripheral wall 8a and a boundary wall 8b. The peripheral wall 8a is cylindrical and extends in the second direction, e.g., a rectangular cylindrical shape. The boundary wall 8b is plate-shaped. The boundary wall 8b is located on the virtual line VL side of the inverter accommodating section 8, i.e., the lower boundary, in the second direction. The boundary wall 8b separates the interior and exterior of the inverter accommodating section 8 in the second direction. The positions of the boundary wall 8b in the second direction differ from each other at each position of the boundary wall 8b in the third direction. In this embodiment, the boundary wall 8b has a pair of first plate portions 8ba extending in a direction perpendicular to the second direction and positioned at different positions in the second direction, and a second plate portion 8bb connecting the pair of first plate portions 8ba and extending in a direction perpendicular to the third direction. The second plate portion 8bb is not limited to the above configuration and may extend in the circumferential direction along the outer periphery of the motor 2, or may have another shape. The boundary wall portion 8b may also be referred to as a bottom wall portion.

[0060] In this embodiment, the distance between the boundary wall 8b and the output shaft J5 in the second direction is smaller than the distance between the boundary wall 8b and the motor shaft J2. Specifically, the distance between the other first plate 8ba of the pair of first plate portions 8ba located on the other side in the third direction and the output shaft J5 is shorter than the distance in the second direction between the motor shaft J2 and one of the pair of first plate portions 8ba located on one side in the third direction. That is, in the portion of the inverter accommodating section 8 that overlaps with the output shaft J5 when viewed from the second direction, the boundary wall 8b is positioned close to the output shaft J5, ensuring a large accommodating space for components. Therefore, by arranging electronic components and other components of the inverter 12 that tend to be bulky in size in the accommodating space, the dead space within the housing 6 can be effectively utilized, thereby enabling the drive device 100 to be miniaturized.

[0061] The inverter lid 13 has a flat plate shape that expands in a direction perpendicular to the second direction. The inverter lid 13 extends in the third direction. The inverter lid 13 covers the opening of the inverter accommodating section 8. The inverter lid 13 is attached to the inverter accommodating section 8 from a predetermined direction. In this embodiment, the direction in which the inverter lid 13 is attached to the inverter accommodating section 8 is the second direction (Z-axis direction). That is, the predetermined direction is the second direction, specifically the vertical direction. As shown in FIG. 5 , the inverter lid 13 is placed on the opening of the inverter accommodating section 8, i.e., in contact with the opening, and is fastened to the inverter accommodating section 8 from the second direction by a screw member (not shown). According to this embodiment, the inverter 12 is fixed to the inverter lid 13, and more specifically, the board 12a and electronic components 12b are fixed thereto. This reduces heat transfer from the motor 2, thereby improving the cooling efficiency of each component of the inverter 12 via the refrigerant flow path 11 (described later). The inverter accommodating portion 8 or the inverter lid portion 13 has a cylindrical member 15. The cylindrical member 15 extends in a predetermined direction, that is, the second direction. Other configurations of the cylindrical member 15 will be described later.

[0062] As shown in Figures 4 and 5, the heat exchanger 9 is fixed to the housing 6. In this embodiment, the heat exchanger 9 is located on the opposite side of the output shaft J5 from the motor shaft J2 in the third direction. The heat exchanger 9 is fixed to a wall portion of the housing 6 facing the other side in the third direction. The heat exchanger 9 has a portion facing the inverter accommodating portion 8. In this embodiment, an upper portion of the heat exchanger 9 faces the peripheral wall portion 8a of the inverter accommodating portion 8. This embodiment makes it possible to effectively utilize dead space that was unused in conventional drive devices. Although not specifically shown, part of the oil path through which the oil O circulates passes through the heat exchanger 9. In other words, part of the oil path through which the oil O flows is disposed in the heat exchanger 9.

[0063] Although not specifically shown, 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 on the opposite side of the motor shaft J2 from the output shaft J5 in the third direction. The pump is located in the housing 6 on the opposite side of the motor shaft J2 in the third direction. On the other hand The pump is fixed to a wall portion facing the side. The pump is arranged, for example, alongside the heat exchanger 9 in the first direction. The pump pumps up oil O from an oil reservoir P and sends it to the heat exchanger 9. The oil O that has exchanged heat 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.

[0064] As shown in Fig. 4, the refrigerant flow path 11 passes through the inverter lid 13, a part of the housing 6, and the heat exchanger 9. A cooling medium cooled by a radiator (not shown) flows through the refrigerant flow path 11. The refrigerant flow path 11 cools the inverter unit 7 and oil O. The refrigerant flow path 11 has an electronic component cooling section 11a, a heat exchange section 11b, a lid-side opening 11c, an accommodation-side opening 11d, and a seal bolt 11e.

[0065] Electronic component cooling unit 11a is disposed on inverter lid 13 and cools electronic component 12b. The cooling medium flows through electronic component cooling unit 11a from one side to the other side in the third direction. Electronic component cooling unit 11a includes switching element cooling unit 11aa and capacitor cooling unit 11ab. Switching element cooling unit 11aa cools switching element 12ba. Capacitor cooling unit 11ab is disposed on inverter lid 13 on the other side in the third direction of switching element cooling unit 11aa and cools capacitor 12bb. Capacitor cooling unit 11ab is located downstream of switching element cooling unit 11aa in refrigerant flow path 11. The cooling medium flowing through the portion of refrigerant flow path 11 located on inverter lid 13 cools switching element 12ba, then capacitor 12bb, and then oil O in heat exchanger 9. This embodiment allows for efficient cooling of components in descending order of heat generation.

[0066] The heat exchanger 11b is disposed in the heat exchanger 9 and exchanges heat between the oil O and the cooling medium. The heat exchanger 11b is a portion of the refrigerant flow path 11 that is located in the heat exchanger 9, and the oil O is cooled by the cooling medium flowing through the heat exchanger 11b.

[0067] 5, lid-side opening 11c is disposed in a portion of refrigerant flow path 11 that connects electronic component cooling section 11a and heat exchange section 11b, and opens to inverter lid 13. Lid-side opening 11c opens to the lower side of inverter lid 13, i.e., the surface facing the inverter accommodating section 8, and extends in the second direction. Lid-side opening 11c is, for example, in the shape of a circular hole.

[0068] The accommodating section-side opening 11d is disposed in a portion of the refrigerant flow path 11 that connects the electronic component cooling section 11a and the heat exchange section 11b, and opens to the inverter accommodating section 8. The accommodating section-side opening 11d opens to the upper side of the inverter accommodating section 8, i.e., the surface facing the inverter lid section 13, and extends in the second direction. In this embodiment, the accommodating section-side opening 11d opens to the upper end surface of the peripheral wall section 8a and extends inside the peripheral wall section 8a in the second direction. The accommodating section-side opening 11d is, for example, in the shape of a circular hole.

[0069] When viewed from a predetermined direction, that is, when viewed from the second direction (Z-axis direction) in this embodiment, the lid portion-side opening 11c and the accommodation portion-side opening 11d overlap and face each other. According to this embodiment, in the second direction in which the inverter lid portion 13 is attached to the inverter accommodation portion 8, the lid portion-side opening 11c and the accommodation portion-side opening 11d face each other, and therefore, by assembling the inverter lid portion 13 to the housing 6, the portion of the refrigerant flow path 11 located at the inverter lid portion 13 and the portion located at the inverter accommodation portion 8 are connected. Therefore, hose members or the like for connecting portions of the refrigerant flow path, as in the conventional case, are not required, and this embodiment reduces the number of parts and simplifies the assembly process.

[0070] The seal bolt 11e closes the end of the electronic component cooling unit 11a on the other side in the third direction. The seal bolt 11e is fixed to the end of the electronic component cooling unit 11a on the other side in the third direction by a screw. By providing the seal bolt 11e, the electronic component cooling unit 11a can be easily separated from the lid unit 11a. side opening The flow path portion that changes the flow direction to the opening portion 11c can be configured compactly and simply. In addition, by removing the seal bolt 11e, the inside of the flow path of the electronic component cooling portion 11a can be easily accessed.

[0071] The cylindrical member 15 is shaped like a pipe 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 lid-side opening 11c and the accommodation-side opening 11d are connected via the cylindrical member 15. According to this embodiment, the provision of the cylindrical member 15 prevents the cooling medium from leaking from the connection portion of the refrigerant flow path 11 between the lid-side opening 11c and the accommodation-side opening 11d.

[0072] The cylindrical member 15 has 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., the second direction. The cylindrical body 15a has a cylindrical shape centered on a central axis C. The cylindrical body 15a has 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 storage-side opening 11d. In other words, the cylindrical member 15 has the first insertion portion 15aa and the second insertion portion 15ab.

[0073] The flange portion 15b protrudes from the outer peripheral surface of the cylindrical body 15a. The flange portion 15b is plate-shaped and extends in a direction perpendicular to the central axis C. The flange portion 15b is annular about the central axis C of the cylindrical member 15, and is annular plate-shaped in this embodiment. Although not particularly shown, a through-hole penetrates the flange portion 15b in a predetermined 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 screw member. A plurality of fixing members are provided. The number of fixing members is the same as the number of through-holes. The fixing members are inserted into the through-holes and fixed to the inverter accommodating portion 8 or the inverter lid portion 13. That is, the cylindrical member 15 is fixed to the inverter accommodating portion 8 or the inverter lid portion 13. According to this embodiment, the cylindrical member 15 can be attached to the inverter accommodating section 8 or the inverter lid section 13 with high precision, and leakage of the cooling medium from the connection portion between the lid section side opening 11c and the accommodating section side opening 11d is further suppressed.

[0074] The O-rings 15c and 15d are annular and elastically deformable. In this embodiment, a pair of O-rings 15c and 15d are provided. The pair of O-rings 15c and 15d are attached to the first insertion portion 15aa and the second insertion portion 15ab, respectively, and contact the inner circumferential surface of the lid-side opening 11c or the inner circumferential surface of the storage-side opening 11d.

[0075] Although the embodiments of the present invention have been described above, the configurations and combinations thereof in the embodiments are merely examples, and additions, omissions, substitutions, and other modifications of the configurations are possible without departing from the spirit of the present invention. Furthermore, the present invention is not limited to the embodiments. For example, in the above-described embodiment, the heat exchanger 9 is configured to cool the oil O using a cooling medium flowing therethrough. In other words, the heat exchanger 9 may be configured to heat the cooling medium using the oil O flowing therethrough. [Explanation of symbols]

[0076] 1,100...drive unit, 2...motor, 3...transmission mechanism, 4...reduction gear, 5...differential gear, 6...housing, 8...inverter housing, 8b...boundary wall, 9...heat exchanger, 10...pump, 11...refrigerant flow path, 11a...electronic component cooling section, 11b...heat exchange section, 11c...lid side opening, 11d...housing side opening, 12...inverter, 12a...board, 12b...electronic component, 12ba...switching element, 12bb...capacitor, 13...inverter lid, 20...rotor, 21...shaft, 30...stator, 35...motor side connection section, 41...first gear, 42...second gear, 51...ring gear, 52...differential case, 55...axle (drive shaft), 56...bearing support section, 60...motor housing section, 62...gear housing section, 81...part, 90 ...oil passage, 661...opening, J2...motor shaft, J4...intermediate shaft, J5...output shaft, O...oil, VL...virtual line

Claims

1. a motor having a rotor that rotates around a motor axis extending in a first direction, and a stator; an inverter that supplies power to the motor; a transmission mechanism that transmits the rotation output from the motor to an axle that rotates around an output shaft; a housing having a motor housing portion that houses the motor, an inverter housing portion that houses the inverter, and a gear housing portion that houses the transmission mechanism; an inverter lid portion that closes the opening of the inverter accommodating portion; a heat exchanger fixed to the housing and having a part of an oil passage through which oil flows disposed therein; a refrigerant flow path through which a cooling medium flows, the refrigerant flowing through the inverter lid, a part of the housing, and the heat exchanger; the motor has a motor-side connection portion that protrudes from the stator and is electrically connected to the inverter, The motor shaft and the output shaft extend parallel to each other, the inverter is positioned in a second direction perpendicular to the first direction with respect to the motor shaft, and extends in a third direction perpendicular to the first direction and the second direction; When viewed from the first direction, a virtual line passing through the motor shaft and the output shaft extends in the third direction, the inverter accommodating portion overlaps with the motor shaft and the output shaft when viewed from the second direction, the inverter accommodating portion has a boundary wall portion located on a boundary of the inverter accommodating portion on the side of the imaginary straight line in the second direction, In the second direction, a distance between the boundary wall portion and the output shaft is smaller than a distance between the boundary wall portion and the motor shaft, the motor-side connection portion has a portion located on the opposite side of the motor shaft from the output shaft in the third direction, The electronic components of the inverter are fixed to the inverter lid, The refrigerant flow path is an electronic component cooling unit that is disposed on the inverter lid and cools the electronic components; a heat exchange portion disposed in the heat exchanger and exchanging heat between the oil and the cooling medium; a lid-side opening that is disposed in a portion of the refrigerant flow path that connects the electronic component cooling unit and the heat exchange unit and that opens to the inverter lid; an accommodation section side opening that is disposed in a portion of the refrigerant flow path that connects the electronic component cooling section and the heat exchange section, and that opens to the inverter accommodation section; When viewed from a predetermined direction, the lid-side opening and the storage-side opening overlap and face each other. Drive unit.

2. a motor having a rotor that rotates around a motor axis extending in a first direction, and a stator; an inverter that supplies power to the motor; a transmission mechanism that transmits the rotation output from the motor to an axle that rotates around an output shaft; a housing having a motor housing portion that houses the motor, an inverter housing portion that houses the inverter, and a gear housing portion that houses the transmission mechanism; a heat exchanger fixed to the housing and having a part of an oil passage through which oil flows disposed therein; a refrigerant flow path through a portion of the housing and the heat exchanger, through which a cooling medium flows; the motor has a motor-side connection portion that protrudes from the stator and is electrically connected to the inverter, The motor shaft and the output shaft extend parallel to each other, the inverter is positioned in a second direction perpendicular to the first direction with respect to the motor shaft, and extends in a third direction perpendicular to the first direction and the second direction; When viewed from the first direction, a virtual line passing through the motor shaft and the output shaft extends in the third direction, the inverter accommodating portion overlaps with the motor shaft and the output shaft when viewed from the second direction, the inverter accommodating portion has a boundary wall portion located on a boundary of the inverter accommodating portion on the side of the imaginary straight line in the second direction, In the second direction, a distance between the boundary wall portion and the output shaft is smaller than a distance between the boundary wall portion and the motor shaft, the motor-side connection portion has a portion located on the opposite side of the motor shaft from the output shaft in the third direction, the refrigerant flow path has a heat exchange portion that 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 output shaft from the motor shaft in the third direction. Drive unit.

3. an end portion of the inverter accommodating portion on one side in the third direction overlaps with an end portion of the stator on one side in the third direction when viewed from the second direction; 3. The drive device according to claim 1 or 2.

4. the inverter has one or more substrates; At least one of the substrates overlaps with the motor shaft and the output shaft when viewed from the second direction. The drive device according to claim 2 .

5. the inverter includes a switching element and a capacitor; The capacitor overlaps with the output shaft when viewed from the second direction.

5. The drive device according to claim 2 or 4.

6. an inverter lid that closes the opening of the inverter accommodating section, The electronic components of the inverter are fixed to the inverter lid. The drive device according to claim 2 .

7. The transmission mechanism includes: a reduction gear including a first gear fixed to a shaft of the rotor and a second gear meshing with the first gear and rotating about an intermediate shaft; a differential device having a ring gear connected to the reduction gear device and rotating around the output shaft, the intermediate shaft is located in the second direction with respect to the imaginary line, When viewed from the first direction, the second gear and the inverter overlap each other. A drive device according to any one of claims 1 to 6.

8. the transmission mechanism includes a reduction gear device that reduces the rotation speed of the motor, and a differential gear device that transmits the rotation of the motor reduced in the reduction gear device to the axle; When viewed from the first direction, the motor and the differential device overlap. A drive device according to any one of claims 1 to 6.

9. the transmission mechanism includes a reduction gear device that reduces the rotation speed of the motor, and a differential gear device that transmits the rotation of the motor reduced in the reduction gear device to the axle; When viewed from the first direction, the reduction gear device and the inverter accommodating portion overlap with each other. A drive device according to any one of claims 1 to 6.

10. In the housing, the motor housing portion and the inverter accommodating portion are a single member. A drive device according to any one of claims 1 to 6.

11. the transmission mechanism includes a reduction gear device that reduces the rotation speed of the motor, and a differential gear device that transmits the rotation of the motor reduced in the reduction gear device to the axle; the inverter accommodating portion opens to one side in the second direction and overlaps with a portion of the differential device when viewed from the second direction, a portion of the inverter accommodating portion that overlaps with a part of the differential device when viewed from the second direction is recessed toward the one side in the second direction relative to a portion of a surface of the inverter accommodating portion facing the other side in the second direction other than the portion of the inverter accommodating portion that overlaps with the part of the differential device when viewed from the second direction; The drive device according to claim 10.

12. The differential device includes a ring gear that meshes with a gear of the reduction device, and a differential case that has an outer diameter smaller than that of the ring gear, The inverter accommodating portion overlaps with the differential case when viewed from the second direction. The drive device according to claim 11.

13. a drive shaft to which rotation is transmitted from the differential device, the housing has a bearing support portion that supports a bearing that rotatably supports the drive shaft at a location spaced apart from a ring gear of the differential device in the first direction, the bearing support portion faces the inverter accommodating portion in the radial direction; 13. A drive device according to claim 11 or 12.

14. a motor having a rotor rotatable around a motor shaft extending in a first direction; an inverter for controlling the current supplied to the motor; a transmission mechanism that transmits the power of the motor to an axle; a housing that accommodates the motor, the inverter, and the transmission mechanism; a heat exchanger fixed to the housing and having a part of an oil passage through which oil flows disposed therein; a refrigerant flow path through a portion of the housing and the heat exchanger, through which a cooling medium flows; the housing includes an inverter accommodating portion that accommodates the inverter, the transmission mechanism includes a reduction gear device that reduces the rotation speed of the motor, and a differential gear device that transmits the rotation of the motor reduced in the reduction gear device to the axle; When viewed from the first direction, the inverter accommodating portion and the differential device overlap with each other, the heat exchanger has a portion facing the inverter accommodating portion in a direction perpendicular to the first direction and in which the inverter extends. Drive unit.

Images