Drive device

Abstract

[Problem] To provide a drive device that comprises a breather chamber and has exceptional properties for mounting to a vehicle. [Solution] A drive device comprising a motive power transmission mechanism that transmits rotation between a motor and a drive wheel, a housing that accommodates the motor and the motive power transmission mechanism and has a breather chamber, and an attachment part on a vehicle-facing side, wherein: the housing includes a body portion that has a first accommodation chamber in which the motor is accommodated, and a cover that is attached to the body portion from the direction of the rotation axis of the motor to form the breather chamber and a second accommodation chamber in which the motive power transmission mechanism is accommodated; the cover includes a bulging part to which the attachment part is provided; and the bulging part bulges in a direction away from the body portion along a rotation axis of the motor and has, in the interior of the bulging part, an expanded space that communicates with the breather chamber.

Description

Drive device

[0001] The present invention relates to a drive device.

[0002] Patent Document 1 discloses a drive device mounted on an electric vehicle or the like. <X

[0003] International Publication No. 2023 / 189033

[0004] In the drive device of Patent Document 1, the input shaft and the output shaft of the power transmission unit are arranged in a direction parallel to the longitudinal direction of the vehicle. Patent Document 1 discloses a mounting structure for firmly mounting this drive device to the vehicle body.

[0005] This type of drive device has an air breather for releasing the pressure inside the drive device to the outside. In the housing of the drive device, the inside of the housing and the air breather are in communication via a breather chamber. When the pressure inside the housing becomes high, the vaporized oil is trapped in the breather chamber so that it is difficult to reach the air breather. In order to trap the oil, a certain volume is required in the breather chamber. Therefore, in order to provide the breather chamber, the housing tends to become larger. When the housing becomes larger, it affects the mountability of the drive device to the vehicle. Therefore, there is a need for a drive device provided with a breather chamber and having excellent mountability to a vehicle.

[0006] One aspect of the present invention is a drive device including: a power transmission mechanism that transmits rotation between a motor and a drive wheel; a housing that houses the motor and the power transmission mechanism and has a breather chamber; and a mounting portion having a fastening portion fixed to a mounting member on the vehicle side, wherein the housing includes: a main body portion having a first housing chamber that houses the motor; and a cover that is attached to the main body portion from the axial direction of the rotation shaft of the motor and forms a second housing chamber that houses the power transmission mechanism and the breather chamber, the cover has a bulging portion provided with the mounting portion, the bulging portion bulges in a direction away from the main body portion along the rotation shaft of the motor, and the inside of the bulging portion has an expansion space communicating with the breather chamber.

[0007] According to one aspect of the present invention, a drive unit equipped with a breather chamber can be provided, which offers excellent mountability on a vehicle.

[0008] Figure 1 is a schematic diagram illustrating the arrangement of the drive unit in the vehicle. Figure 2 is a schematic diagram showing the general configuration of the drive unit. Figure 3 is a schematic diagram illustrating the third housing chamber. Figure 4 is a schematic diagram of the drive unit with the second cover removed, viewed from the second cover side. Figure 5 is a schematic diagram of the drive unit viewed from the front of the vehicle. Figure 6 is a schematic diagram showing the side view of the drive unit viewed from the second cover side. Figure 7 is a schematic diagram showing the side view of the drive unit viewed from the first cover side. Figure 8 is a schematic diagram of the drive unit viewed from above in the Z direction. Figure 9 is a schematic diagram of the drive unit viewed from below in the Z direction. Figure 10 is a schematic diagram of the drive unit viewed from the rear of the vehicle in the Y direction. Figure 11 is a schematic diagram of the second cover viewed from the motor case side. Figure 12 is an enlarged view of the main part of Figure 11. Figure 13 is a schematic diagram illustrating the expanded space. Figure 14 is a schematic diagram illustrating the breather chamber. Figure 15 is a schematic diagram illustrating the breather chamber. Figure 16 is a schematic diagram illustrating the expanded space. Figure 17 is a schematic diagram illustrating the expanded space. Figure 18 is a diagram illustrating the bulge on the first cover side.

[0009] First, the definitions of terms used in this specification will be explained. A drive unit is a device having at least a motor, an inverter, and a power transmission mechanism. A "motor" is a rotating electric machine having electric motor function and / or generator function. An "inverter" is a device that supplies driving current to the motor. A "power transmission mechanism" is, for example, at least one of a gear mechanism, a differential gear mechanism, and a reduction mechanism. A "housing" is a device that houses the motor, gears, and inverter. A housing consists of one or more cases.

[0010] "Overlapping in a specified direction" means that multiple elements are aligned in a specified direction, and is synonymous with the statement "overlapping in a specified direction." The "specified direction" can be, for example, the axial direction, radial direction, vertical direction (direction of gravity), or vehicle travel direction (vehicle forward direction, vehicle reverse direction). If multiple elements (parts, sections, etc.) are shown aligned in a specified direction in the drawing, it can be assumed that there is a statement in the specification explaining that they overlap in a specified direction.

[0011] "Not overlapping in a given direction" and "offset in a given direction" mean that multiple elements are not aligned in a given direction, and are equivalent to stating "not overlapping in a given direction" and "offset in a given direction." "Given direction" can be, for example, axial direction, radial direction, vertical direction, or vehicle travel direction (vehicle forward direction, vehicle reverse direction). If a drawing shows that multiple elements (parts, sections, etc.) are not aligned in a given direction, it can be assumed that the description in the specification includes a statement explaining that they do not overlap in a given direction.

[0012] The statement "In a predetermined viewing direction, the first element (part, component, etc.) is located between the second element (part, component, etc.) and the third element (part, component, etc.)" means that, when observed from a predetermined direction, the first element can be observed to be located between the second and third elements. The "predetermined direction" includes the axial direction, radial direction, vertical direction (direction of gravity), and vehicle travel direction (vehicle forward direction, vehicle reverse direction). For example, if the second, first, and third elements are arranged in this order along the axial direction, then in a radial viewing direction, the first element can be said to be located between the second and third elements. If the drawing shows that the first element is located between the second and third elements in a predetermined viewing direction, then it can be assumed that there is a statement in the specification explaining that the first element is located between the second and third elements in a predetermined viewing direction.

[0013] "Axial direction" refers to the axial direction of the rotation axis of the components that make up the drive system. "Radial direction" refers to the direction perpendicular to the rotation axis of the components that make up the drive system. Examples of components include motors, gear mechanisms, differential gear mechanisms, etc.

[0014] "Downstream side in the direction of rotation" refers to the downstream side in the direction of rotation when the vehicle is moving forward or when the vehicle is moving backward. It is preferable to place it on the downstream side in the direction of rotation when the vehicle is moving forward, as this is the more frequent scenario.

[0015] "Longitudinal mounting" of the drive unit means that the inverter is located on one side of the motor's rotation axis in the horizontal direction relative to the drive unit's installation on the vehicle. Here, "horizontal direction" does not mean the horizontal direction in a strict sense. Furthermore, "longitudinal mounting" of the drive unit means that the drive unit is arranged in a direction in which the input shaft, intermediate shaft, and output shaft of the power transmission mechanism are aligned in the vertical direction relative to the drive unit's installation on the vehicle. In this specification, an example is given in which the intermediate shaft, which transmits rotation between the input shaft and the drive shaft (output shaft), is located between the input shaft, which receives the motor's rotation, and the drive shaft (output shaft) that transmits rotation to the drive wheels below the input shaft.

[0016] The drive unit of this embodiment will be described below, with an example of its installation in a vehicle. Figure 1 is a schematic diagram illustrating the arrangement of the drive unit 1 in a vehicle V. Figure 2 is a schematic diagram showing the general configuration of the drive unit 1. Figure 3 is a schematic diagram illustrating the third housing chamber S3. In Figure 3, a schematic cross-section of the housing HS is shown along the line A-A in Figure 2. Note that the motor M is not shown in Figure 3.

[0017] In the following explanation, the vertical direction (direction of gravity) may be denoted by the symbol "Z", the width direction of the vehicle V by the symbol "X", and the longitudinal direction of the vehicle V by the symbol "Y", with the installation state of the drive unit 1 on the vehicle V as the reference point. Here, the X direction is the direction along the rotation axis X1 of the motor M of the drive unit 1 (see Figure 2), and is the width direction of the vehicle V. The Y direction is the horizontal direction perpendicular to the vertical line LV (see Figure 3) passing through the rotation axis X1 of the motor M of the drive unit 1, and is the longitudinal direction of the vehicle V. Therefore, when "front side" is written, it means the "front side" in the longitudinal direction of the vehicle, and when "rear side" is written, it means the "rear side" in the longitudinal direction of the vehicle. Furthermore, "up and down direction" means the vertical direction when the drive unit 1 is mounted on the vehicle V as the reference point. Therefore, when "up side" is written, it means the "up side" in the vertical direction, and when "down side" is written, it means the "down side" in the vertical direction.

[0018] As shown in Figure 1, at the front of the vehicle V, frames FR, FR are arranged with a gap between them in the width direction of the vehicle V (vertical direction of the paper: X direction). The drive unit 1 is positioned at the front of the vehicle V, between frames FR, FR. The housing HS of the drive unit 1 consists of a motor case 6 (main body), a first cover 7, a second cover 8, and a third cover 9.

[0019] As shown in Figure 2, the housing HS contains a motor M, a power transmission mechanism 3, and a differential mechanism 4. Furthermore, an inverter INV is also housed inside (see Figure 3). In the drive unit 1, the motor M is driven by the current supplied from the inverter INV and outputs rotational driving force. As shown in Figure 2, the rotation output by the motor M is reduced in speed by the power transmission mechanism 3 and then transmitted to the differential mechanism 4. The rotation transmitted to the differential mechanism 4 is distributed to the left and right drive shafts DS, DS (output shafts), causing the drive wheels WH, WH connected to the drive shafts DS, DS to rotate. In the drive unit 1, rotational transmission between the motor M and the drive wheels WH, WH is possible via the power transmission mechanism 3, the differential mechanism 4, and the drive shafts DS, DS.

[0020] In this configuration, the drive unit 1 in the vehicle V is positioned such that the rotation axis X1 of the motor M is aligned with the width direction (X direction, left-right direction in Figure 2) of the vehicle V.

[0021] In the housing HS, the first cover 7 is fixed to one side of the motor case 6 in the X direction (left side in the figure) with bolts (not shown). The second cover 8 is fixed to the other side of the motor case 6 in the X direction (right side in the figure) with bolts (not shown). Furthermore, as shown in Figure 3, the third cover 9 is fixed to one side of the motor case 6 in the Y direction (right side in the figure: rear side of the vehicle) with bolts (not shown).

[0022] As shown in Figure 2, the motor case 6 has a first housing section 61 having a cylindrical peripheral wall section 610 and a second housing section 62 having a cylindrical peripheral wall section 620. The outer diameter of the peripheral wall section 610 is smaller than the outer diameter of the peripheral wall section 620. That is, the opening area of ​​the peripheral wall section 610 is smaller than the opening area of ​​the peripheral wall section 620. The motor case 6 has a basic shape in which a part of the peripheral wall section 610 is inserted inside the peripheral wall section 620. In this state, in the motor case 6, a part of the upper region in the Z direction (the region shown by the intersecting hatching in Figure 2) is a region in which the peripheral wall section 610 and the peripheral wall section 620 are integrated. When the motor case 6 in this state is viewed from the X direction, the peripheral wall section 610 is positioned in a positional relationship that overlaps with the upper region of the peripheral wall section 620. Therefore, when viewed from the X direction, the lower region of the peripheral wall section 620 does not overlap with the region of the peripheral wall section 610.

[0023] The peripheral wall portion 610 has an opening at one end in the X direction (the end on the first cover 7 side). The other end of the peripheral wall portion 610, located inside the peripheral wall portion 620 (the end on the second cover 8 side), is sealed by the bottom wall portion 63. The bottom wall portion 63 closes the opening of the peripheral wall portion 610 at a position offset from the other end 6b of the motor case 6 toward the first cover 7 side (left side in the figure).

[0024] In the first housing section 61, the inside of the peripheral wall 610 forms the first housing chamber S1 for housing the motor M. The first housing chamber S1 is a roughly cylindrical space. The motor case 6 is positioned so that the opening of the first housing chamber S1 is aligned with the X direction. The opening of the first housing chamber S1 is closed by the first cover 7.

[0025] A cylindrical member 64 is fitted inside the first housing section 61. The cylindrical member 64 is inserted into the first housing section 61 from the first cover 7 side (left side in the figure). The tip 64b of the cylindrical member 64 abuts against the bottom wall 63 from the X direction. A groove 641 is provided on the outer circumference of the cylindrical member 64. The groove 641 is a continuous spiral groove along the outer circumference of the cylindrical member 64. The groove 641 extends circumferentially along the outer circumference of the cylindrical member 64, while continuously changing its position in the X direction (left-right direction in the figure) on the outer circumference of the cylindrical member 64.

[0026] The cylindrical member 64 forms a cooling passage 642 through which cooling water flows between the inner circumference of the first housing portion 61 (circumferential wall portion 610) and the groove 641. The third cover 9, which will be described later, is provided with a cooling water supply port 97 (see Figure 9). As shown in Figure 2, cooling water is supplied to the cooling passage 642 located on the base end 64a side of the cylindrical member 64 via the supply port 97. The cooling water supplied to the cooling passage 642 moves circumferentially along the outer circumference of the cylindrical member 64 and is then discharged from the outlet 96 (see Figure 3) on the tip 64b side.

[0027] As shown in Figure 2, a motor M is provided on the inner circumference of the cylindrical member 64. The motor M has a motor shaft 20, a rotor 21, and a stator 22. The stator 22 is fitted and fixed to the inner circumference of the cylindrical member 64, and the rotor 21 is positioned on the inner circumference of the stator 22. The motor shaft 20 is provided horizontally in a direction along the X direction. The center of the motor shaft 20 is located on the rotation axis X1, and the motor shaft 20 rotates integrally with the rotor 21. In the first cover 7, a ring-shaped support portion 731 is provided in the region that intersects with the rotation axis X1 of the motor M. A bearing Br is supported on the inner circumference of the support portion 731. The end of the motor shaft 20 on the first cover 7 side (one end) penetrates the wall portion 71 of the first cover 7 in the X direction and is located in a fifth housing chamber S5 that houses a sensor (not shown). The motor shaft 20 on the side facing the first cover 7 is rotatably supported by the first cover 7 via a bearing Br.

[0028] The end of the motor shaft 20 on the second cover 8 side (the other end) penetrates the bottom wall 63 of the first housing 61 in the X direction. In the bottom wall 63, a through hole 630 and a support portion 631 surrounding the through hole 630 are provided in the region intersecting with the rotation axis X1 of the motor M. A bearing Br is supported on the inner circumference of the support portion 631. The second cover 8 side of the motor shaft 20 is rotatably supported in the bottom wall 63 via the bearing Br. The end of the motor shaft 20 on the second cover 8 side (the right end in the figure) penetrates the bottom wall 63 towards the second cover 8 side and is located inside the second housing chamber S2.

[0029] The second housing chamber S2 is a space formed between the motor case 6 (second housing section 62) and the second cover 8. The second housing chamber S2 is formed inside the housing HS by closing the opening in the peripheral wall 620 of the second housing section 62 with the second cover 8. The power transmission mechanism 3 is housed in the second housing chamber S2.

[0030] The power transmission mechanism 3 includes an input shaft 31 having an input gear 311, an intermediate shaft 32 having an idler gear 321 and a reduction gear 322, a differential mechanism 4 having a final gear 33, and drive shafts DS and DS (output shafts) extending from the differential mechanism 4.

[0031] The input shaft 31 has a shaft portion 310 that is arranged coaxially with the rotation axis X1 of the motor M. One end of the shaft portion 310 (the end on the motor M side) is connected to the motor shaft 20 so as not to rotate relative to it. The other end of the shaft portion 310 is rotatably supported by a bearing Br in a support hole 811 provided in the second cover 8. The input gear 311 is provided on the shaft portion 310 at a position closer to the support hole 811 (to the right in the figure) so as not to rotate relative to the shaft portion 310.

[0032] The intermediate shaft 32 has a shaft portion 320 arranged parallel to the rotation axis X1 of the motor M. The shaft portion 320 is oriented along an axis X2 parallel to the rotation axis X1. One end of the shaft portion 320 (the end on the motor M side) is rotatably supported by a bearing Br in a support hole 632 provided in the bottom wall portion 63. The other end of the shaft portion 320 is rotatably supported by a bearing Br in a support hole 812 provided in the second cover 8. The idler gear 321 is positioned on the shaft portion 320 closer to the second cover 8 (to the right in the figure) and is not rotatable relative to the shaft portion 320. The idler gear 321 is meshed with the input gear 311 of the input shaft 31 so as to transmit rotation.

[0033] The reduction gear 322 is positioned on the shaft portion 320 closer to the motor M and is mounted so as not to rotate relative to the shaft portion 320. The reduction gear 322 meshes with the final gear 33, which is fixed to the outer circumference of the differential case 40, in a manner that allows for rotational transmission.

[0034] The differential case 40 is a hollow member having a space inside that can accommodate the pinion gear 41 and the side gear 42. Viewed from the X direction, the differential case 40 is located in the lower region of the second housing chamber S2, below the first housing chamber S1. On the outer circumference of the differential case 40, the final gear 33 is fixed to the second cover 8 side. Inside the differential case 40, the pinion gear 41 on the differential case 40 side and the drive shaft DS and the side gear 42 on the DS side are meshed in a way that allows rotational transmission. When the differential case 40 rotates around the axis X3, the rotation of the differential case 40 is transmitted to the left and right drive shafts DS, DS via the pinion gear 41 and the side gear 42, causing the left and right drive wheels WH, WH to rotate. The differential case 40, pinion gear 41 and side gear 42 constitute the differential mechanism 4.

[0035] The second housing section 62 has a side wall 65 that closes the opening on the first cover 7 side (left side in the figure). The side wall 65 is positioned offset to the first cover 7 side (left side in the figure) from the bottom wall 63 in order to secure space for housing the differential case 40. The side wall 65 extends from approximately the center of the first housing section 61 in the X direction downward in the Z direction. The side wall 65 connects to the peripheral wall 620 by traversing the side of the differential case 40 downward from the outer circumference of the first housing section 61. The lower region of the peripheral wall 620 extends below the differential case 40 towards the second cover 8 side (right side in the figure) while avoiding interference with the differential case 40.

[0036] The side wall portion 65 is provided with an insertion hole 650 for the drive shaft DS and a support portion 653 surrounding the insertion hole 650. A cylindrical portion 401 extending from the differential case 40 is inserted into the support portion 653. The outer circumference of the cylindrical portion 401 is rotatably supported by a bearing Br supported on the inner circumference of the support portion 653. In the differential case 40, a cylindrical portion 401 is also provided on the second cover 8 side in the X direction. In the second cover 8, an insertion hole 810 into which the cylindrical portion 401 is inserted and a support portion 813 surrounding the insertion hole 810 are provided in the region facing the cylindrical portion 401. The outer circumference of the cylindrical portion 401 is rotatably supported by a bearing Br supported on the inner circumference of the support portion 813.

[0037] In the differential case 40, one drive shaft DS and the other drive shaft DS are inserted into the cylindrical portion 401 on one side and the other cylindrical portion 401 on the other side. The aforementioned side gears 42, 42 are connected to the ends of these drive shafts DS, DS so as not to rotate relative to each other. The drive shafts DS, DS are rotatable around an axis X3 parallel to the rotation axis X1 of the motor M.

[0038] Figure 4 is a schematic diagram of the drive unit 1 with the second cover 8 removed, viewed from the second cover 8 side. In Figure 4, the external appearance of the input gear 311 of the input shaft 31, the idler gear 321 of the intermediate shaft 32, and the final gear 33 are shown by dashed lines, and the arrangement of the input gear 311, idler gear 321, and final gear 33 in the second housing chamber S2 is schematically shown. Furthermore, in order to make the extent of the peripheral wall portion 620 easier to understand, intersecting hatching is added to the end face 620a of the peripheral wall portion 620 on the near side of the paper.

[0039] As shown in Figure 4, when the motor case 6 is viewed from the second cover 8 side, the peripheral wall portion 620 surrounding the second housing portion 62 is open. The end face 620a on the near side of the paper of the peripheral wall portion 620 is the joint with the second cover 8 side. When viewed from the X direction (near side of the paper), the peripheral wall portion 620 has a substantially elliptical shape in which the length in the vertical direction (Z direction) is longer than the length in the left-right direction (Y direction). Inside the peripheral wall portion 620, the bottom wall portion 63 is located on the upper side in the Z direction, and the side wall portion 65 is located on the lower side in the Z direction. The far side of the bottom wall portion 63 is the first housing chamber S1 (see Figure 2) that houses the motor M. The side wall portion 65 is located further back in the paper than the bottom wall portion 63. The differential case 40 (see Figure 2) is housed on the near side of the side wall portion 65.

[0040] In the bottom wall portion 63, a through hole 630 and a support portion 631 surrounding the through hole 630 are located approximately in the center in the Y direction. Below the support portion 631 in the Z direction, an insertion hole 650 and a support portion 653 surrounding the insertion hole 650 are located approximately in the center of the area of ​​the side wall portion 65. Above the support portion 653, ribs 655 are provided that surround the support portion 653 at intervals. The ribs 655 protrude from the area of ​​the bottom wall portion 63 toward the foreground of the paper. When viewed from the X direction, the ribs 655 form an arc shape centered on the axis X3. In the drive device 1, below the ribs 655, the final gear 33, which is fixed to the outer circumference of the differential case 40, is arranged concentrically with respect to the axis X3.

[0041] In the motor case 6, the support hole 632 for the intermediate shaft 32 is located between the support portion 631 and the support portion 653 in the Z direction. The support hole 632 is located to the right of the vertical line LV perpendicular to the rotation axis X1 of the motor M, and is located on the third cover 9 side (right side in the figure) of the support portions 631 and 653. Figure 4 shows the horizontal line LH1 perpendicular to the vertical line LV and the rotation axis X1, and the horizontal line LH2 perpendicular to the vertical line LV and the axis X3. The support hole 632 is provided with a position offset from the support portions 631 and 653 in the direction of the horizontal line LH1 (Y direction). When viewed from the direction of the rotation axis X1 of the motor M, the support hole 632 in the bottom wall portion 63 is provided in the region that overlaps with the first housing chamber S1 (see Figure 2) described above.

[0042] In the motor case 6, a disc portion 643 that bulges upward is provided on the outer circumference of the arc-shaped rib 655. The support hole 632 is provided in the disc portion 643, with its opening facing the second cover 8 side. The support hole 632 is located between the horizontal line LH1 passing through the rotation axis X1 of the motor M and the horizontal line LH2 passing through the axis X3, and is positioned on the third cover 9 side (right side in the figure) of the vertical line LV passing through the rotation axis X1 of the motor M.

[0043] As shown in FIG. 1, the drive device 1 is vertically arranged with the third cover 9 facing the rear of the vehicle V. In this state, as shown in FIG. 2, the input shaft 31 of the power transmission mechanism 3, the intermediate shaft 32, and the drive shafts DS, DS (output shafts) are arranged in this order from the upper side to the lower side. Further, as shown in FIG. , the axis (axis line X2) of the intermediate shaft 32 is located on the side of the third cover 9 with respect to the straight line (vertical line LV) connecting the axis (rotation axis X1 of the motor M) of the input shaft 31 and the axis (axis line X3) of the output shaft (drive shaft DS). The axis (rotation axis X1 of the motor M) of the input shaft 31 is located above the axis (axis line X2) of the intermediate shaft 32. The axis (axis line X2) of the intermediate shaft 32 is located above the axis (axis line X3) of the output shaft (drive shaft DS).

[0044] As shown in FIG. 3, in the motor case 6, a cylindrical peripheral wall portion 660 is provided on the side surface on the rear side of the vehicle. The rear side of the vehicle as viewed in the direction of the rotation axis X1 is one side (the right side in the figure) of the vertical line LV orthogonal to the rotation axis X1 of the motor M. As viewed in the direction of the rotation axis X1, the peripheral wall portion 660 opens on one side (the right side in the figure) in the horizontal line LH1 direction (the left - right direction in the figure) orthogonal to the vertical line LV. The cylindrical peripheral wall portion 92 of the third cover 9 is assembled to the peripheral wall portion 660 from one side in the horizontal line LH1 direction. The opening of the peripheral wall portion 660 is sealed by the third cover 9, and a third accommodation chamber S3 for accommodating the inverter INV is formed between the peripheral wall portion 610 of the motor case 6. Inside the third accommodation chamber S3, the inverter INV is vertically arranged with the thickness direction of the inverter INV along the horizontal line LH1 direction (the left - right direction in the figure). In this state, the third accommodation chamber S3 is located on one side (the rear side of the vehicle V) of the vertical line LV as viewed from the rotation axis X1 of the motor M. Further, the third accommodation chamber S3 is located on the upper side in the Z direction in the drive device 1. Therefore, as viewed from the X direction, the center of gravity G of the drive device 1 is located on the lower side on the rear side of the vehicle with respect to the rotation axis X1 of the motor M. As shown by the arrow in the figure, a moment in the direction of tilting the upper side where the third accommodation chamber S3 is provided of the drive device 1 toward the rear side of the vehicle acts on the drive device 1.

[0045] Figure 5 is a schematic view of the drive device 1 as seen from the front side of the vehicle in the Y direction. Figure 6 is a view schematically showing a side view of the drive device 1 as seen from the side of the second cover 8 in the X direction. In Figure 5, the positions of the fastening points (fastening parts with the vehicle body side) between the brackets BK1 to BK4 on the vehicle side and the mounting parts AT (AT1 to AT4) on the drive device 1 side are indicated by arrows, and the number of fastening points is indicated by the number of arrows. In a part where the arrows are arranged in series, it shows that the fastening points are arranged from the front side to the back side of the paper surface. In Figure 6, in order to clearly show the positions of the boss parts 88A to 88E and 89A to 89C which are the fastening points, hatching intersecting the end faces on the front side of the paper surface of the boss parts 88A to 88E and 89A to 89C is shown.

[0046] As shown in Figure 5, four mounting parts AT (AT1 to AT4) are set on the housing HS of the drive device 1. The drive device 1 is connected to the brackets BK (BK1 to BK4) on the vehicle body side at these four mounting parts AT (AT1 to AT4). The mounting parts AT (AT1 to AT4) are set in position on the housing HS in order to properly support the drive device 1 on the vehicle body side without tilting the drive device 1.

[0047] Two mounting parts AT2 and AT3 are set on the second cover 8. In the second cover 8, the mounting part AT2 is provided on the upper side surface in the Z direction. As shown in Figure 6, the mounting part AT2 is composed of five boss parts 88A to 88E having bolt holes 88a. These boss parts 88A to 88E correspond to the fastening parts with the vehicle body side.

[0048] The boss part 88A is provided coaxially with the rotation axis X1 of the motor M (input shaft 31: see Figure 2). The boss parts 88B and 88E are located slightly above the horizontal line LH1 passing through the rotation axis X1. The boss parts 88B and 88E are provided in a symmetric positional relationship with the vertical line LV passing through the rotation axis X1 in between. The boss parts 88B and 88E are located at the same distance from the horizontal line LH1 in the direction of the vertical line LV.

[0049] Boss sections 88C and 88D are located above boss sections 88B and 88E. Boss sections 88C and 88D are located closer to the vertical line LV than boss sections 88B and 88E, and are positioned symmetrically with respect to the vertical line LV. Boss sections 88C and 88D are located at the same distance from the horizontal line LH1 in the direction of the vertical line LV. Boss sections 88B to 88E are located above boss section 88A.

[0050] Viewed from the direction of the rotation axis X1 of the motor M, the bosses 88B to 88E are arranged in a clockwise direction from the front of the vehicle, along a virtual circle Im centered on the rotation axis X1, in the order of boss 88B, boss 88C, boss 88D, and boss 88E.

[0051] Adjacent boss sections 88B and 88C, and boss sections 88D and 88E, in the circumferential direction around the rotation axis X1, are connected by linear ribs 881 and 881, respectively. The ribs 881 and 881 are positioned symmetrically with respect to a vertical line LV in between. Adjacent boss sections 88C and 88D, in the circumferential direction, are connected by a linear rib 882. The rib 882 is positioned approximately parallel to the horizontal line LH1.

[0052] Viewed from the X direction, boss portion 88A, located on the rotation axis X1, is connected to boss portions 88B to 88E, each located above the horizontal line LH1, via ribs 883 and 884. Ribs 883 and 884 extend linearly from boss portion 88A radially outward from the rotation axis X1. Boss portion 88A and boss portions 88B and 88E are connected by ribs 883 and 883 that are approximately parallel to the horizontal line LH1. Boss portion 88A and boss portions 88C and 88D are connected by linear ribs 884 and 884. Ribs 883 and 884 located on the vehicle front side (left side in the figure) of the vertical line LV and ribs 883 and 884 located on the vehicle rear side (right side in the figure) are positioned in a positional relationship that is approximately symmetrical with respect to the vertical line LV. When viewed from the direction of the rotation axis X1, the ribs 883 and 884 are arranged substantially radially with the boss portion 88A as the center.

[0053] The surfaces surrounding the bolt holes 88a in the boss portions 88A to 88E (shown as hatched surfaces in the figure) are flat end surfaces aligned with the Z direction and serve as mounting surfaces for the bracket BK2 (see Figure 5). As shown in Figure 5, in this embodiment, in the upper region of the second cover 8, bolts (not shown) that penetrate the bracket BK2 on the vehicle body side are screwed into each of the boss portions 88A to 88E located on the side of the drive unit 1. As a result, the drive unit 1 is supported on its X-direction side by the vehicle body via the bracket BK2.

[0054] Here, as shown in Figure 6, when the second cover 8 is viewed from the X direction, the mounting portion AT2 has two boss portions 88B, 88C and two boss portions 88D, 88E, respectively, on one side (vehicle front side) and the other side (vehicle rear side) of the vertical line LV, above the boss portion 88A which is arranged coaxially with the rotation axis X1 of the motor M. As described above, a moment (see Figure 3) acts on the drive unit 1 in a direction that tilts the upper side where the third cover 9 (third housing chamber S3) is located toward the vehicle rear side (right side in the figure). The five boss portions 88A to 88E are connected to the bracket BK2, so that even when a moment is applied, the tilt of the upper side of the drive unit 1 toward the vehicle rear side is restricted, and the drive unit 1 is properly supported.

[0055] As shown in Figure 6, the mounting portion AT3 is provided on the lower side surface of the second cover 8 in the Z direction. The mounting portion AT3 consists of three boss portions 89A to 89C, each having a bolt hole 89a. Boss portion 89A is located on the front side of the vehicle (left side in the figure) when viewed from the vertical line LV passing through the rotation axis X1. When viewed from the direction of the vertical line LV, a portion of the vertical line LV side of boss portion 89A (right side in the figure) overlaps with the aforementioned boss portion 88A. Furthermore, a portion of the vertical line LV side of boss portion 89A overlaps with the support portion 813 surrounding the aforementioned insertion hole 810. Therefore, when viewed from the direction of the vertical line LV, boss portion 89A is provided in a positional relationship where a portion of the vertical line LV side overlaps with boss portion 88A and support portion 813. Note that the area of ​​boss portion 89A that overlaps with support portion 813 is larger than the area that overlaps with boss portion 88A.

[0056] Furthermore, when viewed from the direction of the vertical line LV, the boss portion 89A is positioned on the opposite side of the vertical line LV, slightly overlapping with the aforementioned boss portion 88C. In this state, the boss portion 89A is located below the horizontal line LH2 passing through the axis X3 and the support portion 813. Therefore, when viewed from the insertion hole 810 (support portion 813), the boss portion 89A is located diagonally downward on the front side of the vehicle.

[0057] The bosses 89B and 89C are located on the rear side of the support portion 813. The bosses 89B and 89C are aligned in the front-to-rear direction (Y direction) of the vehicle, with their positions aligned in the vertical line LV direction (up and down direction in the figure). The bosses 89B and 89C are located above the horizontal line LH2 and below the third cover 9. When viewed from the direction of the horizontal line LH2, the bosses 89B and 89C overlap with the support portion 813 surrounding the insertion hole 810. When viewed from the vertical line LV direction, the bosses 89B and 89C overlap with the aforementioned bosses 88D and 88E, respectively.

[0058] The surfaces surrounding the bolt holes 89a in the boss portions 89A to 89C (shown as hatched surfaces in the figure) are flat end surfaces aligned with the Z direction and serve as mounting surfaces for the bracket BK3 (see Figure 5). In this embodiment, in the area below the second cover 8, bolts (not shown) that penetrate the vehicle body bracket BK3 are screwed into each of the boss portions 89A to 89C located on the side of the drive unit 1. As a result, the drive unit 1 is supported by the vehicle body on its X-direction side (the left side of the vehicle V) via the brackets BK2 and BK3.

[0059] Thus, in the mounting portion AT3, two boss portions 89B and 89C are provided at a position that is rearward of the vertical line LV passing through the rotation axis X1 and overlaps with the support portion 813 when viewed from the Y direction. Furthermore, a boss portion 89A is located in front of the vertical line LV passing through the rotation axis X1 and below the support portion 813. As described above, a moment acts on the drive unit 1 in a direction that tilts it towards the rear of the vehicle (right side in the figure) on the upper side where the third cover 9 (third housing chamber S3) is located (see Figure 3). The boss portions 89B and 89C are connected to the bracket BK3, which restricts the tilt of the upper side of the drive unit 1 towards the rear of the vehicle.

[0060] Furthermore, when the upper side of the drive unit 1, where the third housing chamber S3 is located, is tilted towards the rear of the vehicle, a rotational force acts on the diagonally downward portion of the support portion 813 on the front side of the vehicle, rotating in a clockwise direction as shown in Figure 6, with the center of gravity G (see Figure 3) as the center of gravity. At the mounting portion AT3, a boss portion 89A connected to the bracket BK3 is located below the support portion 813. As a result, the boss portion 89A restricts rotation in the clockwise direction, and thus the tilting of the upper side of the drive unit 1 towards the rear of the vehicle can also be restricted at the boss portion 89A.

[0061] Thus, since the second cover 8 is provided with mounting sections AT2 and AT3 separated into upper and lower parts, the side of the drive unit 1 on the second cover 8 side is properly supported by the vehicle body while restricting the tilt of the drive unit 1.

[0062] Figure 7 is a schematic diagram showing the drive unit 1 as viewed from the first cover 7 side in the X direction. In Figure 7, intersecting hatching is added to the side surface of the bulging portion 73 to make the extent of the bulging portion 73 easier to understand. Furthermore, intersecting hatching is added to the end face on the near side of the paper to make the positions of the boss portions 69A, 69B and the contact portion 69C easier to understand. Figure 8 is a schematic diagram showing the drive unit 1 as viewed from above in the Z direction. In Figure 8, intersecting hatching is added to the area of ​​the flat portion 74 to make the position of the mounting portion AT1 easier to understand. Figure 9 is a schematic diagram showing the drive unit 1 as viewed from below in the Z direction. Figure 10 is a schematic diagram showing the drive unit 1 as viewed from the rear side of the vehicle in the Y direction.

[0063] As shown in Figure 7, a bulge 73 is provided on the upper part of the first cover 7, bulging out toward the front of the paper. Viewed from the X direction, the bulge 73 is provided in a substantially arc shape centered on the rotation axis X1 of the motor M. The bulge 73 has a portion that crosses the upper side of the rotation axis X1 in the Y direction (left-right direction in the figure). The bulge 73 has a portion that crosses a vertical line LV perpendicular to the rotation axis X1 of the motor M from one side to the other. Viewed from the Y direction, the bulge 73 has a portion that overlaps with the rotation axis X. As shown in Figure 8, viewed from the Z direction, the bulge 73 extends away from the motor case 6 (left direction in the figure). A flat portion 74 is provided on the upper surface of the bulge 73. The flat portion 74 is provided in contact with the side edge 742 of the bulge 73 on the opposite side from the motor case 6 (left side in the figure). In a top view, the flat portion 74 is formed with an X-direction range that extends to the vicinity of the motor case 6. Furthermore, the flat portion 74 is formed with a range that crosses the rotation axis X1 of the motor M in the Y-direction (front-rear direction of the vehicle V).

[0064] The flat section 74 is provided with three bolt holes 74a, 74b, and 74c. Viewed from the Z direction, one bolt hole 74a is positioned to overlap with the rotation axis X1. The remaining two bolt holes 74b and 74c are positioned symmetrically with respect to the rotation axis X1. The bolt holes 74b and 74c are aligned in the direction of the rotation axis X1. The bolt holes 74b and 74c are located further from the motor case 6 than bolt hole 74a. In the flat section 74, a recess 741 is provided between bolt holes 74b and 74c. Viewed from the Z direction, the recess 741 has a roughly rectangular shape. Viewed from the Z direction, the recess 741 has a basic shape in which a part of the area of ​​the flat section 74 is recessed from the side edge 742 toward the motor case 6. The bottom of the recess 741 is located toward the motor case 6, and the opening is located on the opposite side from the motor case 6 (left side in the figure).

[0065] The bracket BK1 is placed on the upper surface of the flat portion 74, and bolts (not shown) are screwed into the bolt holes 74a to 74c, thereby fixing the bracket BK1 to the mounting portion AT1 of the drive unit 1 (first cover 7). As a result, the first cover 7 side of the drive unit 1 is supported in a suspended state from the bracket BK1 on the vehicle body side (see Figure 5). These bolt holes 74a to 74c correspond to the fastening portion with the vehicle body side. This fastening portion is located above the rotation axis X1 of the motor M.

[0066] Furthermore, when viewed from above in the Z direction, of the bolt holes 74a to 74c, which are the fastening points between the bracket BK1 and the mounting part AT1, bolt holes 74b and 74c are located on the rear side and front side of the vehicle, with the rotation axis X1 of the motor M in between. The bolt holes 74b and 74c are positioned so that they are aligned in the direction of the rotation axis X1 (left-right direction in the figure). As described above, a moment (see Figure 3) acts on the drive unit 1, tilting the upper side where the third cover 9 is located toward the rear of the vehicle. By arranging the bolt holes 74b and 74c as described above, the tilt of the drive unit 1 can be appropriately restricted.

[0067] As shown in Figure 7, the mounting portion AT4 is provided in the lower region of the side surface of the motor case 6 on the first cover 7 side in the X direction. The mounting portion AT4 consists of a boss portion 69A with one bolt hole 69a, a boss portion 69B with two bolt holes 69b and 69c, and a contact portion 69C. The boss portion 69A is located in front of the vehicle (right side in the figure) when viewed from the vertical line LV passing through the rotation axis X1. When viewed from the X direction, the boss portion 69A is located below the support portion 653 surrounding the insertion hole 650. When viewed from the direction of the vertical line LV, a part of the vertical line LV side of the boss portion 69A (left side in the figure) overlaps with the support portion 653 surrounding the insertion hole 650. Therefore, when viewed from the insertion hole 650 (support portion 653), the boss portion 69A is located diagonally downward in front of the vehicle. The surface surrounding the bolt hole 69a in the boss portion 69A (shown as a hatched surface in the figure) is a flat end surface that aligns with the Z direction and serves as the mounting surface for the bracket BK4 (see Figure 5).

[0068] The boss portion 69B is located on the rearward side of the vehicle relative to the vertical line LV. The boss portion 69B is provided in a range that crosses the horizontal line LH2, which is perpendicular to the axis X3, in the Z direction (up and down direction in the figure). When viewed from the Y direction, the boss portion 69B overlaps with the support portion 653. In the boss portion 69B, bolt holes 69b and 69c are aligned in the Z direction. One bolt hole 69b is located below the horizontal line LH2. The other bolt hole 69c is located above the horizontal line LH2. The surface surrounding the bolt holes 69b and 69c in the boss portion 69B (shown as a hatched surface in the figure) is a flat end surface along the Z direction and serves as the mounting surface for the bracket BK4 (see Figure 5).

[0069] Viewed from the support portion 653, the contact portion 69C of the bracket BK4 is provided on the opposite side (right side in the figure) from the boss portion 69B. Viewed from the Y direction, the contact portion 69C overlaps with the lower portion of the support portion 653 and the boss portion 69B. The end face of the contact portion 69C on the near side of the paper (the hatched surface in the figure) is a flat end face along the Z direction. When attaching the bracket BK4 (see Figure 5) to the boss portions 69A and 69B, a part of the bracket BK4 is brought into contact with the contact portion 69C from the X direction. The bolt holes 69a to 69c of the boss portions 69A and 69B correspond to the fastening portions with the vehicle body. By screwing bolts (not shown) that pass through the bracket BK4 on the vehicle body side into each of the bolt holes 69a to 69c, the bracket BK4 is fixed to the mounting portion AT4 of the drive unit 1 (motor case 6). As a result, when viewed from the rear of the vehicle, the drive unit 1 is supported by the vehicle body via bracket BK4 on the side located on the right side of the vehicle.

[0070] As shown in Figure 7, the mounting portion AT4 has a boss portion 69B located behind the vertical line LV passing through the rotation axis X1, and overlapping with the support portion 653 when viewed from the Y direction. Furthermore, a boss portion 69A is located in front of the vertical line LV passing through the rotation axis X1, and below the support portion 653. As described above, a moment (see Figure 3) acts on the drive unit 1, tilting the upper side where the third cover 9 (third housing chamber S3) is located toward the rear of the vehicle (left side in the figure). The boss portions 69A and 69B are connected to the bracket BK4, which restricts the tilt of the upper side of the drive unit 1 toward the rear of the vehicle. Furthermore, when the upper side of the drive unit 1 where the third cover 9 (third housing chamber S3) is located tilts toward the rear of the vehicle, the diagonally downward side of the support portion 653 toward the front of the vehicle rotates around the center of gravity G (see Figure 3). At the mounting portion AT4, the boss portion 69A connected to the bracket BK4 is located diagonally downward when viewed from the support portion 653. This arrangement allows the boss portion 69A to restrict the tilt of the upper side of the drive unit 1 toward the rear of the vehicle.

[0071] As described above, on the right side of the drive unit 1 on the vehicle V (see Figure 1), mounting parts AT1 and AT4 are provided separately in the upper and lower sections. This allows the side of the drive unit 1 on the first cover 7 side to be properly supported by the vehicle body while restricting the tilt of the drive unit 1.

[0072] As shown in Figure 10, a cooling water supply port 97 is provided at the bottom of the third cover 9. The supply port 97 is positioned with its opening facing the rear of the vehicle in the Y direction (towards the viewer). A cooling water supply pipe Pin (see Figure 7) is connected to the supply port 97 from the rear of the vehicle. The cooling water supplied to the supply port 97 cools the inverter INV (see Figure 3) inside the third cover 9, and then is supplied to a cooling water passage (cooling passage 642: see Figure 2) provided in the motor case 6. In the cooling passage 642, the supplied cooling water cools the motor M as it flows from one end 6a to the other end 6b of the motor case 6. The cooling water that reaches the end 6b is discharged from an outlet 96 (see Figures 3 and 10) provided at the bottom of the motor case 6. The outlet 96 is positioned with its opening facing downwards in the Z direction. A cooling water discharge pipe (see Figure 7) is connected to the discharge port 96 from below.

[0073] Here, there is space below the third cover 9 of the drive unit 1 (see the hatched area labeled R1 in Figures 3, 7, 9, and 10). As shown in Figure 7, in this embodiment, the cooling water discharge pipe Pout is positioned using this area labeled R1. Therefore, the aforementioned boss portion 69B of the motor case 6 is positioned offset to the support portion 653 side (right side in the figure) in the Y direction to avoid interference with the discharge pipe Pout connected to the discharge port 96. In other words, the discharge port 96 is located next to the boss portion 69B. In this embodiment, the bolt holes 69b and 69c of the boss portion 69B are aligned vertically so that the bracket BK4 (see Figure 5) attached to the boss portion 69B does not protrude significantly into area R1. This ensures that there is enough space to position the discharge pipe Pout without reducing the number of fastening points between the boss portion 69B and the bracket BK4.

[0074] Figure 11 is a schematic diagram of the second cover 8 as seen from the motor case 6 side. Figure 12 is an enlarged view of the main part of Figure 11. Figure 12 shows the upper side of the second cover 8. In Figures 11 and 12, intersecting hatches are added to the front-facing end face 82a of the peripheral wall portion 82 of the second cover 8 and the ribs 83, 84, and 85 to make their positions easier to understand. Figure 13 is a schematic diagram illustrating the expanded space. In Figure 13, a cross-section along line A-A in Figure 12 is schematically shown. Figure 14 is a schematic diagram illustrating the breather chamber S4. Figure 15 is a schematic diagram illustrating the breather chamber S4. In Figure 15, a cross-section obtained by cutting the second cover 8 along line A-A in Figure 14 is schematically shown. In Figure 15, hatches are added to the cross-section of the second cover 8.

[0075] As shown in Figure 11, the second cover 8 has a bottom wall portion 81 extending along the Z direction and a peripheral wall portion 82 surrounding the entire outer circumference of the bottom wall portion 81. The end face 82a on the near side of the paper of the peripheral wall portion 82 is the joint surface with the motor case 6 (see Figure 11). In the bottom wall portion 81, a support hole 811 for the shaft portion 310 of the input shaft 31 (see Figure 2) is provided at a position that intersects with the rotation axis X1 of the motor M. The support hole 811 is a bottomed hole recessed in the back side of the bottom wall portion 81. Furthermore, the boss portion 88A is located on the back side of the support hole 811 (see Figures 12 and 13). As shown in Figure 12, a rib 83 extending from the inner circumference of the peripheral wall portion 82 is located above the support hole 811. The rib 83 has a first region 831 connected to the inner circumference of the peripheral wall portion 82, a second region 832 extending from the tip of the first region 831 in the tangential direction to the support hole 811, and a third region 833 extending from the tip of the second region 832 in the direction of the horizontal line LH1.

[0076] The base end 831a of the first region 831 is connected to the inner circumference of the peripheral wall portion 82 on the vehicle-front side of the vertical line LV passing through the rotation axis X1. Figure 12 shows the lines L1, L2, and L3 extending radially around the rotation axis X1. Line L1 is located on the vehicle-front side (right side in the figure) of the vertical line LV, and lines L2 and L3 are located on the rear side (left side in the figure). Line L2 is located between lines L1 and L3 in the circumferential direction around the rotation axis X1. The first region 831 extends linearly from the peripheral wall portion 82 toward the rotation axis X1 along line L1. The base end 832a of the second region 832 is connected to the first region 831 on the vehicle-front side of the vertical line LV. The base end 832a of the second region 832 is connected to the first region 831 on line L1. The second region 832 crosses the vertical line LV from the first region 831 toward the rear of the vehicle along the straight line Lm that extends tangentially to the support hole 811. The tip 832b side of the second region 832 forms an arc shape along the outer circumference of the support hole 811. The base end 833a of the third region 833 is connected to the outer circumference of the tip 832b of the second region 832 from the direction of the straight line L3.

[0077] The base end 833a of the third region 833 extends towards the rear of the vehicle along the direction of the horizontal line LH1, then curves downward and crosses the horizontal line LH1 in the direction of the vertical line LV. Below the horizontal line LH1, the third region 833 is bent towards the rear of the vehicle. The third region 833 extends in the direction of the horizontal line LH1. The tip 833b of the third region 833 faces the inner circumference of the peripheral wall portion 82 with a gap S83 between them. This gap S83 becomes the entrance to the breather chamber S4 (see Figure 14), which will be described later.

[0078] A rib 84 is provided on the straight line L3 of the second cover 8. The base end 84a of the rib 84 is connected to the inner circumference of the peripheral wall portion 82. The tip 84b of the rib 84 faces the outer circumference of the tip 832b side of the aforementioned rib 83 with a gap S84 between them. A rib 85 is provided on the straight line L2 of the second cover 8. The base end 85a of the rib 85 is connected to the inner circumference of the peripheral wall portion 82. The tip 85b of the rib 85 faces the outer circumference of the second region 832 of the aforementioned rib 83 with a gap S85 between them.

[0079] In the second cover 8, a rib 86 is provided on the vehicle front side (right side in the figure) when viewed from the support hole 811. The base end 86a of the rib 86 is positioned opposite the base end 832a of the second region 832, with a gap between them. The rib 86 extends diagonally downward from the second region 832 along the tangent Ln of the support hole 811. The tip 86b of the rib 86 is bent radially outward (vehicle front side) below the horizontal line LH1. These ribs 83, 84, 85, and 86 are provided at the same height in the X direction (height from the front to the back of the figure) as the end face 82a on the front side of the peripheral wall portion 82. In other words, the X-direction positions of the ribs 83, 84, 85, and 86 are aligned with the end face 82a.

[0080] In this embodiment, a region partitioned by the rib 83 (the region on the outer diameter side of the rib 83) is formed within the second cover 8. The region on the outer diameter side of the rib 83 is further partitioned by ribs 84 and 85. The region on the outer diameter side of the rib 83 forms part of the space that functions as a breather chamber S4 (see Figure 14) when the second cover 8 is assembled to the motor case 6.

[0081] As shown in Figure 4, the motor case 6 is provided with a plurality of ribs 671-676 and 678-681 on the part facing the second cover 8. The ribs 671-676 and 678-681 are provided protruding from the bottom wall 63 toward the second cover 8 side (towards the viewer). In other words, the ribs 671-676 and 678-681 form recessed areas on the bottom wall 63 side (towards the viewer) of the motor case 6. In the motor case 6, a disc portion 670 surrounding the support portion 631 is provided on the part facing the second cover 8. A plurality of ribs 671-676, 678, and 679 extending radially outward from the rotation axis X1 are connected to the outer circumference of the disc portion 670. These ribs 671-676, 678, and 679 connect the outer circumference of the disc portion 670 to the inner circumference of the peripheral wall portion 620. When viewed from the direction of the rotation axis X1, the ribs 671-676, 678, and 679 are arranged radially around the disc portion 670.

[0082] Viewed from the direction of the rotation axis X1, the outer diameter of the input gear 311 (input shaft 31) is smaller than the outer diameter of the motor M (see Figure 4). Therefore, there is space around the input shaft 31 (rotation axis X1) inside the motor case 6. In the drive unit 1, the idler gear 321 (intermediate shaft 32) is located diagonally below and to the rear of the vehicle when viewed from the input gear 311. Therefore, in this embodiment, the space inside the housing HS above the idler gear 321 and around the input gear 311 is used as a breather chamber S4 (see Figure 14).

[0083] When the second cover 8 is assembled to the motor case 6, the ribs 675, 676, 679, and 681 of the motor case 6 come into contact with the ribs 83, 84, and 85 of the second cover 8 (see Figure 12), forming a space that functions as a breather chamber S4 (see Figure 14).

[0084] As shown in Figure 4, rib 675 is provided along the straight line L1 where the first region 831 (see Figure 12) of rib 83 is located. Rib 676 is provided along the straight line L2 where rib 85 (see Figure 12) is located. Rib 679 is provided along the straight line L3 where rib 84 (see Figure 12) is located. Rib 680, which extends upward from the lower disc portion 643, is connected to rib 679. Rib 681 is connected to the portion of rib 680 that is on the rib 679 side. Rib 681 extends from the inner circumference of the peripheral wall portion 620 in a direction along the horizontal line LH1 and connects to rib 680. Rib 681 is provided in a position that overlaps with the third region 833 of rib 83 when viewed from the direction of the rotation axis X1.

[0085] As shown in Figure 15, when the second cover 8 is assembled to the motor case 6, the ribs 83, 84, and 85 on the second cover 8 side overlap the ribs 675, 676, 679, and 681 on the motor case 6 side to form a wall, partitioning the space inside the housing HS to become the breather chamber S4 (see Figures 14 and 15). As shown in Figure 15, in the breather chamber S4, the gap S83 between the tip 833b of the third region 833 of the rib 83 and the inner circumference of the peripheral wall portion 82 serves as an inlet for air and oil OL inside the housing HS. A communication hole 621 is provided in the upper peripheral wall portion 620 of the breather chamber S4, which communicates with the outside. Outside the motor case 6, a breather hose 10 (see Figure 8) is connected to the communication hole 621. When the pressure inside the housing HS increases, air inside the housing HS flows into the breather chamber S4 through the gap S83 and is discharged from the communication hole 621. This reduces the pressure rise inside the housing HS. When the vehicle is moving forward, the oil OL scraped up by the final gear 33 moves upward along the inner circumference of the peripheral wall portion 82 and flows into the breather chamber S4 through the gap S83. In the breather chamber S4, a rib 84 is located above the third region 833 of the rib 83 that forms the gap S83. The gap S84 is provided between the tip 84b of the rib 84 and the base end 833a of the third region 833 of the rib 83. When viewed from the Z direction, the gap S83 and the gap S84 are positioned offset in the Y direction. That is, in order for the oil OL that has flowed into the breather chamber S4 to reach the upper communication hole 621, it is necessary to detour in the Y direction and pass through the gap S84. Because the kinetic energy of the oil OL is reduced by the detour, it becomes more difficult for the oil OL to reach the communication hole 621. In other words, ribs 83 and 84 function as labyrinth seals that restrict the linear movement of oil OL within the breather chamber S4. The labyrinth seals reduce the amount of oil OL that flows into the breather chamber S4 that is ejected from the communication hole 621 to the outside of the housing HS.

[0086] Figure 16 is a schematic diagram illustrating the expanded space. Figure 17 is a schematic diagram illustrating the expanded space. Figure 16 schematically shows a cross-section obtained by cutting the second cover 8 along the line B-B in Figure 14. Figure 17 schematically shows a cross-section obtained by cutting the second cover 8 along the line C-C in Figure 14.

[0087] As shown in Figure 11, the upper side of the second cover 8 is provided with expansion spaces Sa to Sh that expand the space that functions as a breather chamber S4 within the housing HS. The expansion spaces Sa to Sh are arranged in the circumferential direction around the rotation axis X1 along the inner circumference of the peripheral wall portion 82. Of the expansion spaces Sa to Sh, the expansion space Sa located at one end in the circumferential direction and the expansion space Sh located at the other end are located on the horizontal line LH1 passing through the rotation axis X1. The expansion spaces Sa to Sh are arranged to surround the upper outer circumference of the support hole 811 in the Z direction.

[0088] Each of the expanded spaces Sa to Sh has a depth in the X direction (front to back direction on the paper) of the outer diameter region that is greater than the depth in the X direction of the inner diameter region. Here, the depth in the X direction refers to the length from the end face 82a of the peripheral wall portion 82 surrounding each expanded space Sa to Sh to the bottom wall portion 81. For example, Figure 13 shows expanded space Sh as an example. The depth D1 of the outer diameter region Sh1 of expanded space Sh is greater than the depth D2 of the inner diameter region Sh2.

[0089] In this embodiment, the boss portions 88B to 88E, which are fastening points with the vehicle body, are located on the far side of the paper in the region where the expanded spaces Sa, Sc, Se, Sf, and Sh are provided (see Figure 12). As shown in Figure 13, the boss portion 88B is provided on the second cover 8 at a position that overlaps with the expanded space Sh when viewed from the X direction. The boss portion 88B has a bolt hole 88a at its tip for screwing in a bolt that passes through the bracket BK2 (see Figure 5). In this embodiment, the second cover 8 is provided with the expanded space Sh at the base end (lower side in Figure 13) while ensuring the thickness W (see Figure 13) necessary for connection with the bracket BK2 at the tip end of the boss portion 88B. Although detailed illustrations are omitted, similarly for the boss portions 88C, 88D, and 88E, the expanded spaces Sa, Sc, Se, and Sf are provided at positions that overlap with each other when viewed from the X direction, while ensuring the thickness W necessary for providing the bolt hole 88a.

[0090] In this embodiment, as shown in Figure 12, expanded spaces Sb, Sd, and Sg are provided not only at positions overlapping with bosses 88B to 88E (expanded spaces Sa, Sc, Se, Sf, Sh) when viewed from the direction of the rotation axis X1, but also between adjacent bosses in the circumferential direction. Specifically, expanded space Sb is provided between boss 88E and boss 88D, expanded space Sd is provided between boss 88D and boss 88C, and expanded space Sg is provided between boss 88C and boss 88B. These expanded spaces Sa to Sh are formed using the bulge portion 87 of the second cover 8. The bulge portion 87 is a region in which the second cover 8 bulges out in the direction away from the motor case 6. As shown in Figure 17, the bulge portion 87 is formed along a virtual circle Im1 surrounding the rotation axis X1. The virtual circle Im1 is a circle that passes through the region in which expanded spaces Sa to Sh are formed, aligned in the circumferential direction of the rotation axis X1. The bulge portion 87 has a substantially arc shape that follows the circumferential direction around the rotation axis X1. One end 871 and the other end 872 of the bulge portion 87 in the circumferential direction are located below the horizontal line LH1. The boss portions 88B to 88E described above are provided on the bulge portion 87 to avoid interference with the expanded space Sa to Sh. The second cover 8 also has a bulging region (bulge portion 87') formed in the area of ​​the boss portion 88A. The bulge portion 87 with the boss portions 88B to 88E and the bulge portion 87' with the boss portion 88A are connected via ribs 883 and 884. The bulge portion 87 is located on the outer diameter side of the bulge portion 87' and has a portion that is located in the circumferential range around the rotation axis X1.

[0091] Here, Figures 16 and 17 are schematic diagrams of the second cover 8 cut in half, but in Figure 17, the second cover 8 is cut at a position further away from the motor case 6 in the direction of the rotation axis X1 than in Figure 16. In Figure 16, the outlines of the expanded spaces Sa to Sg shown in Figure 17 are shown with dashed lines. The cross-sectional area of ​​the expanded spaces Sa to Sg shown in Figure 17 is smaller than the cross-sectional area of ​​the expanded spaces Sa to Sg shown in Figure 16. That is, in the second cover 8, the cross-sectional area of ​​the expanded spaces Sa to Sg narrows as it moves away from the motor case 6. The outline of the expanded space Sh is not shown in Figure 17, but the cross-sectional area of ​​the expanded space Sh also narrows as it moves away from the motor case 6.

[0092] In this embodiment, the bulging portion 87 is provided with boss portions 88B to 88E, which serve as mounting portions AT2 to the vehicle body, as well as expanded spaces Sa to Sd that communicate with the breather chamber S4. This allows for an increase in the volume of the breather chamber S4 while reducing the weight of the housing HS. Since it is not necessary to enlarge the housing HS to secure the volume of the breather chamber S4, the mountability of the drive unit 1 on the vehicle V is not impaired due to an enlargement of the housing HS. As a result, the drive unit 1 can be equipped with a breather chamber S4 while maintaining excellent mountability on the vehicle V.

[0093] Figure 18 is a diagram illustrating the bulge 73 on the first cover 7 side. Figure 18 schematically shows a cross-section of the bulge 73 of the first cover 7 cut along the line A-A in Figure 8. In Figure 18, the cover member 952 (see Figure 2) of the sensor Sn housing 95 is removed to show the shape of the cylindrical wall portion 951.

[0094] As shown in Figure 2, a bulge 73 is provided on the upper part of the first cover 7, which bulges in the X direction. The bulge 73 extends away from the motor case 6 (to the left in the figure). As shown in Figure 7, when viewed from the X direction, the bulge 73 is provided in a range that crosses the upper side of the rotation axis X1 of the motor M in the Y direction (left-right direction in the figure). Below the bulge 73, a housing 95 for the sensor Sn is provided. As shown in Figure 2, the housing 95 consists of a cylindrical wall portion 951 that protrudes from the outer circumference of the wall portion 71 in the direction of the rotation axis X1, and a cover member 952 that closes the opening of the cylindrical wall portion 951. As shown in Figure 18, when viewed from the X direction, the cylindrical wall portion 951 is located below the bulge 73 with its opening facing towards the front of the paper in the X direction.

[0095] Viewed from the X direction, the cylindrical wall portion 951 has a substantially elongated shape, with its longitudinal direction aligned with the vertical direction. The upper part of the cylindrical wall portion 951 has a portion located above the horizontal line LH1 that intersects the rotation axis X1 of the motor M. The upper region of the cylindrical wall portion 951 is provided in a substantially arc shape so as to surround the rotation axis X1. The region of the cylindrical wall portion 951 below the horizontal line LH1 is inclined with respect to the vertical line LV as it moves downward, with the position in the Y direction positioned towards the rear of the vehicle. Viewed from the X direction, the bottom portion 951c of the cylindrical wall portion 951 is located above the boss portion 69B described above. A connection portion 955 for the sensor Sn is attached to the bottom portion 951c of the cylindrical wall portion 951.

[0096] Various sensors Sn are housed inside the cylindrical wall portion 951. After the sensors Sn are installed inside the cylindrical wall portion 951, the opening of the cylindrical wall portion 951 is closed with a cover member 952 (see Figure 2), thereby preventing moisture from entering the interior of the cylindrical wall portion 951.

[0097] In this embodiment, the bulge 73, when viewed from the X direction, is provided in a range that crosses the upper side of the rotation axis X1 in the Y direction (left-right direction in the figure). When viewed from the Z direction, the bulge 73 overlaps with the housing portion 95 of the sensor Sn (see Figure 9). The upper side of the housing portion 95 is covered by the bulge 73. As shown in Figure 18, the bulge 73 is provided so as to surround the outer circumference of the upper region of the housing portion 95 (cylindrical wall portion 951). The front side of the bulge 73 of the vehicle (right side in the figure) is arc-shaped along a virtual circle Im3 centered on the rotation axis X1. Similarly, the rear side of the bulge 73 of the vehicle (left side in the figure) also has a substantially arc-shaped region along a virtual circle Im3 centered on the rotation axis X1. A hollow portion 730 is provided inside the bulge 73. These hollow sections 730 are in communication with the first housing chamber S1 (see Figure 2) that houses the motor M. By providing the hollow sections 730, the degree of weight increase caused by the provision of the bulging section 73 is suppressed. One end 73a and the other end 73b of the bulging section 73 in the circumferential direction around the rotation axis X1 are each located below the horizontal line LH1.

[0098] Of the bulging portion 73, the outer circumference 735 of the area on the vehicle's front side is arc-shaped, following the virtual circle Im2 surrounding the rotation axis X1. Therefore, at least the area on the vehicle's front side of the bulging portion 73 has an arc-shaped surface with its apex P facing outward. In this case, moisture adhering to the outer circumference 735 easily slides off along the arc-shaped outer circumference. In other words, moisture is less likely to accumulate on the outer circumference 735.

[0099] The inner circumference 733 of the bulging portion 73 faces the outer circumference of the cylindrical wall portion 951 with a gap between them. A boss portion 953 with a screw hole is provided on the upper part of the cylindrical wall portion 951 in the Z direction. When viewed from the Z direction, the boss portion 953 is located offset to the front side of the vehicle (right side in the figure) from the recess 741. The boss portion 953 protrudes upward from the outer circumference of the cylindrical wall portion 951 and is located at the highest position on the upper part of the cylindrical wall portion 951. On the rear side of the boss portion 953, an inclined portion 951a is provided, in which the height in the Z direction decreases as it moves toward the rear of the vehicle. Therefore, if moisture adheres to the upper part of the outer circumference of the cylindrical wall portion 951, the adhered moisture moves downward toward the rear of the vehicle along the inclined portion 951a. At this time, because the boss portion 953 is located on the front side of the inclined portion 951a, the adhered moisture is blocked by the boss portion 953 and is less likely to move toward the front of the vehicle.

[0100] Furthermore, the front side of the boss portion 953 is provided with an arc-shaped portion 951b, the height in the Z direction decreasing as it moves towards the front of the vehicle. Therefore, even if moisture adhering to the upper part of the cylindrical wall portion 951 moves beyond the boss portion 953 towards the front of the vehicle, it is easier for it to slide off along the arc-shaped portion 951b. In this way, by providing an inclined portion 951a and an arc-shaped portion 951b on the upper part of the cylindrical wall portion 951, moisture is less likely to accumulate on the upper outer circumference of the cylindrical wall portion 951. This reduces the possibility of corrosion occurring due to moisture accumulation on the cylindrical wall portion 951, or deterioration of the cylindrical wall portion 951 due to substances precipitated from accumulated moisture.

[0101] As described above, the bulging portion 73 covering the upper side of the cylindrical wall portion 951 is provided with a recess 741, and when viewed from the Z direction, the recess 741 and the cylindrical wall portion 951 overlap. When the drive unit 1 is attached to the vehicle side, the bracket BK1 is fixed to the upper surface of the flat portion 74. That is, the opening of the recess 741 is closed by the bracket BK1, so that moisture does not enter the recess 741 from above and adhere to the upper part of the cylindrical wall portion 951.

[0102] As described above, in the drive unit 1 of this embodiment, the housing HS has a motor case 6 (main body), and the motor case 6 has a first housing chamber S1 for housing the motor M. As shown in Figure 2, the first cover 7 is attached to the motor case 6 from one side in the direction of the rotation axis X1 of the motor M, and closes the opening of the first housing chamber S1. The second cover 8 is attached to the motor case 6 from the other side in the direction of the rotation axis X1 of the motor M, and forms a second housing chamber S2 for housing the power transmission mechanism 3. As shown in Figure 3, the third cover 9 is attached to the motor case 6 from one side (the rear side of the vehicle) of the vertical line LV passing through the rotation axis X1, when viewed from the direction of the rotation axis X1 of the motor M, and forms a third housing chamber S3 for housing the inverter INV.

[0103] As shown in Figure 2, the second housing chamber S2 is provided with a differential case 40, drive shafts DS, DS (output shaft), and an intermediate shaft 32. The differential case 40 and drive shafts DS, DS are located below the first housing chamber S1. As shown in Figure 4, the idler gear 321 of the intermediate shaft 32 is located on one side (the rear side of the vehicle) of the vertical line LV passing through the rotation axis X1. As shown in Figure 3, the motor M located in the upper first housing chamber S1 within the housing HS is positioned such that, when viewed from the Y direction, it overlaps with the inverter INV in the third housing chamber S3.

[0104] Therefore, when viewed from the direction of the rotation axis X1 of the motor M, the center of gravity G of the drive unit 1 is located diagonally below one side (the rear side of the vehicle) of the vertical line LV passing through the rotation axis X1 of the motor M. As a result, a moment acts on the drive unit 1 in a direction that tends to tilt the upper side of the drive unit 1 to the side where the inverter INV is located.

[0105] As shown in Figure 5, the drive unit 1 has mounting parts AT (AT1 to AT4) attached to brackets BK1 to BK4 on the vehicle V side as follows: (a) Mounting part AT1 (first mounting part) is provided on the upper part of the first cover 7 located on one side in the direction of the rotation axis X1 of the motor M, and the first cover 7 is suspended and supported from the vehicle body side. (b) Mounting parts AT2 (second mounting part) and mounting part AT3 (third mounting part) are provided on the upper and lower parts of the side surface of the second cover 8 located on the other side in the direction of the rotation axis X1 of the motor M, and the side surface of the second cover 8 is supported. (c) Mounting part AT4 (fourth mounting part) is provided on the lower side surface of the motor case 6 located on one side in the direction of the rotation axis X1 of the motor M, and the lower part of the motor case 6 is supported.

[0106] In the drive unit 1, mounting parts AT for the vehicle-side bracket BK (BK1 to BK4) are positioned above the motor M's rotation axis X1 (mounting part AT1), above the motor M's rotation axis X1 (input shaft 31 of the power transmission mechanism 3) (mounting part AT2), and below the drive shaft DS (output shaft) side (mounting parts AT3, AT4). The drive unit 1 has the inverter INV mounted vertically on the rear side of the vehicle relative to the motor M, making it prone to tipping over in the front-to-rear direction of the vehicle. However, by arranging these four mounting parts AT in a balanced manner, support stability on the vehicle side can be ensured.

[0107] In particular, the second cover 8 on which the mounting portion AT2 is provided has bulging portions 87 and 87' that bulge out in a direction away from the motor case 6 along the rotation axis X1, as shown in Figure 17. Specifically, the second cover 8 has a bulging portion 87' (first bulging portion) at a position that coincides with the rotation axis X1 when viewed from the X direction, and a bulging portion 87 (second bulging portion) is provided on the outer diameter side of the bulging portion 87'. The mounting portion AT2 has boss portions 88A to 88E, as shown in Figure 6. Boss portion 88A (first fastening portion) is provided concentrically with the input shaft 31 at the tip of the bulging portion 87'. Boss portions 88B to 88E (second fastening portions) are provided on the bulging portion 87 above boss portion 88A.

[0108] The boss portions 88A to 88E provided on the bulging portions 87 and 87' protrude in a direction away from the peripheral wall portion 82 of the second cover 8 (in the direction of the rotation axis X1). Therefore, the boss portions 88A to 88E, which are fastening portions with the bracket BK2, can be positioned closer to the bracket BK2 on the vehicle body side. Thus, when connecting the bracket BK2 on the vehicle body side and the mounting portion AT2, it is not necessary to separately prepare an intermediate member for connection. Therefore, the increase in manufacturing costs due to an increase in the number of parts can be suppressed.

[0109] One boss portion 88A is positioned coaxially with the rotation axis X1 (input shaft 31) of the motor M. Boss portions 88B to 88E are positioned along the circumferential direction around the rotation axis X1, surrounding boss portion 88A. Boss portions 88B, 88C and boss portions 88D, 88E are positioned on the front and rear sides of the vehicle, with boss portion 88A in between. This allows the side of the drive unit 1 on the second cover 8 side to be supported by the vehicle body side with multiple fastening portions provided at a distance from each other. This improves the support rigidity of the drive unit 1 on the vehicle body side.

[0110] Furthermore, when viewed from the direction of the rotation axis X1 of the motor M, the boss portion 88B located on one side of the vertical line LV passing through the rotation axis X1 of the motor M and the boss portion 88E located on the other side are positioned symmetrically with respect to the vertical line LV passing through the rotation axis X1 of the motor M in between. Similarly, the boss portion 88C on one side and the boss portion 88D on the other side are positioned symmetrically. The distance between the boss portion 88B and the boss portion 88E in the direction of the horizontal line LH1 passing through the rotation axis X1 of the motor M is greater than the distance between the boss portion 88C and the boss portion 88D. The drive unit 1 receives vibrations from the vehicle V in the longitudinal direction (horizontal line LH direction: Y direction). The wider the distance between the boss portions 88A to 88E, which are the connection parts with the bracket BK2 on the vehicle V side, the higher the support rigidity of the bracket BK2, and the more the vibrations of the drive unit 1 in the longitudinal direction of the vehicle can be suppressed. The bosses 88B and 88C and bosses 88D and 88E are spaced apart in the direction of the horizontal line LH1 perpendicular to the rotation axis X1 of the motor M, thereby suppressing vibrations of the drive unit 1 in the longitudinal direction of the vehicle. This suppresses deformation of the bracket BK2 caused by vibrations. Furthermore, the mounting portion AT2 can be properly supported by the bracket BK2.

[0111] Furthermore, adjacent boss portions 88B to 88E in the circumferential direction are connected via ribs 881 and 882, and boss portion 88A on the rotation axis X1 is connected to the surrounding boss portions 88B to 88E via ribs 883 and 884. As a result, even if vibrations in the longitudinal direction of the vehicle act on the drive unit 1 when the vehicle V is running, vibrations of the boss portions 88A to 88E, which are the mounting portion AT2 with the bracket BK2, can be suppressed, and deformation of the boss portions 88A to 88E can be suppressed.

[0112] The mounting portion AT3 (third mounting portion) has a boss portion 89A (first fastening portion) located below the drive shaft DS (output shaft), and boss portions 89B and 89C (second fastening portions) located above the boss portion 89A. When viewed from the direction of the rotation axis X1 of the motor M, the boss portions 89B and 89C are arranged side by side on one side of the drive shaft DS, on the rear side of the vehicle of the drive shaft DS (see Figure 2) which is provided on axis X3, while the boss portion 89A is located diagonally below the other side of the drive shaft DS.

[0113] By arranging the bosses 89A to 89C in this manner, the durability against moments that attempt to tilt the drive unit 1 toward the rear of the vehicle can be improved. Specifically, the bosses 89B and 89C receive moments that attempt to move downward the rear side of the drive unit 1 where the third cover 9 is located, thereby reducing the tilt of the drive unit 1 toward the rear of the vehicle. In addition, the boss 89A, located on the opposite side of the bosses 89B and 89C with the drive shafts DS and DS (output shafts) in between, reduces the displacement of the drive unit 1 toward the front of the vehicle, thereby reducing the tilt of the drive unit 1 toward both the front and rear of the vehicle.

[0114] As shown in Figure 7, the mounting portion AT4 (fourth mounting portion) has a boss portion 69A (first fastening portion) located below the drive shaft DS (output shaft) on the axis X3, and a boss portion 69B (second fastening portion) located above the boss portion 69A. When viewed from the direction of the rotation axis X1 of the motor M, the boss portion 69B is located on one side of the drive shaft DS, adjacent to the rear side of the drive shaft DS in the vehicle, while the boss portion 69A is located diagonally below the other side of the drive shaft DS.

[0115] This improves the durability of the drive unit 1 against moments that attempt to tilt it towards the rear of the vehicle. Specifically, the boss portion 69B receives the moment that attempts to move the rear side of the drive unit 1, where the third cover 9 is located, downward, thereby reducing the tilt of the drive unit 1 towards the rear of the vehicle. In addition, the boss portion 69A, located on the opposite side of the boss portion 69B with the drive shafts DS and DS (output shaft) in between, restricts the displacement of the drive unit 1 towards the front of the vehicle, thereby reducing the tilt of the drive unit 1 to both the front and rear of the vehicle.

[0116] As shown in Figure 5, mounting portion AT3 and mounting portion AT4 are positioned in a positional relationship with the final gear 33 (see Figure 2) sandwiched between them in the axial direction (axis X3 direction) of the drive shaft DS. Since mounting portion AT3 and mounting portion AT4 are positioned in a positional relationship with the drive shaft DS and the final gear 33 (gear) on the DS side sandwiched between them, the lower area of ​​the housing HS of the drive unit 1 can be stably supported.

[0117] Viewed from the direction of the motor M's rotation axis X1, mounting portions AT3 and AT4 are provided with one boss portion 89A and 69A, respectively, on the vehicle front side of the drive shaft DS (output shaft). Bosses 89B and 89C, and boss portion 69B, respectively, are provided on the vehicle rear side of the drive shaft DS (output shaft). This allows the vehicle body brackets BK3 and BK4, which support the lower side of the drive unit 1, to be positioned further rear than the drive shaft DS (output shaft). In a vehicle, it is necessary to position drive units such as steering that extend beyond the width of the drive unit 1 in the X direction near the drive shaft DS. By positioning brackets BK3 and BK4 on the vehicle rear side, the drive units can be positioned in front of the drive shaft DS, avoiding the area behind the drive shaft DS. Furthermore, space can be secured below the third cover 9 on the vehicle rear side for providing a cooling water supply pipe Pin and a discharge pipe Pout.

[0118] As shown in Figure 17, expanded spaces Sa to Sd, which communicate with the breather chamber S4 (see Figure 15), are provided inside the bulging portion 87. The expanded spaces Sa to Sd allow for an increase in the volume of the breather chamber S4 while reducing the weight of the housing HS. Since it is not necessary to enlarge the housing HS to secure the volume of the breather chamber S4, the mountability of the drive unit 1 on the vehicle V is not impaired due to the enlargement of the housing HS. As a result, the drive unit 1, which is equipped with a breather chamber S4, has excellent mountability on the vehicle V.

[0119] As shown in Figure 18, the first cover 7 is provided with a bulge 73 above the sensor Sn housing 95, which is located on one side of the housing HS in the direction of the motor M's rotation axis X1. The bulge 73 extends from one side of the housing HS in the direction of the motor M's rotation axis X1 toward the rotation axis X1 and crosses above the sensor Sn housing 95 in the circumferential direction around the motor M's rotation axis X1. This reduces the possibility of water splashing onto the sensor Sn housing 95 from above where the bulge 73 is located.

[0120] In the vertical LV direction, with reference to the installation state of the drive unit 1 on the vehicle V, a mounting portion AT1 for the vehicle-side bracket BK1 is provided on the upper part of the bulging portion 73. When the bracket BK1, which is the mounting member on the vehicle body side, is attached to the upper part of the bulging portion 73, the bracket BK1 functions as a canopy that restricts the intrusion of moisture into the area where the sensor Sn housing portion 95 and the cover member 952 are provided. This further reduces the possibility of water splashing onto the sensor Sn housing portion 95 and the cover member 952 from above in the vertical LV direction. In the direction of the rotation axis X1 of the motor M, the bulging portion 73 protrudes outward from the cover member 952. The mounting portion AT1 is provided on this bulging portion 73. Compared to the case where the mounting portion AT1 is provided on the lower motor case 6, the mounting portion AT1 can be positioned closer to the vehicle-side support member located on the side of the drive unit 1 in the X direction. Therefore, even when the motor M and the vehicle-side support member are positioned far apart when viewed from the Y direction, the mounting portion AT1 is provided on the bulging portion 73, eliminating the need to enlarge the connecting member to the support member. This effectively reduces the increase in vehicle weight caused by an enlarged connecting member.

[0121] In the above-described embodiment, an example was given in which the mounting portion AT1 is provided on the upper part of the first cover 7. The mounting portion AT1 may also be provided on the side of the first cover 7 or on the upper surface of the motor case 6.

[0122] In the above embodiment, an example was given in which the mounting portion AT1 has three bolt holes 74a to 74c as fastening portions. The total number of bolt holes is not limited to three. Also, the arrangement of the bolt holes can be changed as appropriate.

[0123] In the above-described embodiment, an example was given in which the mounting portion AT2 has boss portions 88A to 88E. The total number of boss portions is not limited to this embodiment. The number and position of the boss portions can be changed as appropriate depending on the desired support stability, etc.

[0124] In the above-described embodiment, an example was given in which the mounting portion AT3 has three boss portions 89A to 89C. The total number of boss portions is not limited to this embodiment. The number of boss portions can be appropriately changed depending on the required support stability, etc. Furthermore, although an example was given in which one bolt hole 89a is provided for each of the boss portions 89A to 89C, a boss portion with two bolt holes may also be used.

[0125] In the above-described embodiment, an example was given in which the mounting portion AT4 has two boss portions 69A and 69B. The total number of boss portions is not limited to this embodiment. The number of boss portions can be appropriately changed depending on the required support stability, etc. Alternatively, instead of the two boss portions 69A and 69B, three boss portions with one bolt hole each may be provided.

[0126] The configuration of the drive unit 1 for a vehicle according to this embodiment is listed below. (1) The drive unit 1 comprises a power transmission mechanism 3 that transmits rotation between a motor M and drive wheels WH, WH, a housing HS that houses the motor M and the power transmission mechanism 3 and has a breather chamber S4, and a mounting portion AT to the vehicle V side. The housing HS has a motor case 6 (main body) having a first housing chamber S1 for housing the motor M, and a second cover 8 (cover) that is attached to the motor case 6 from the direction of the rotation axis X1 of the motor M and forms a second housing chamber S2 for housing the power transmission mechanism 3 and a breather chamber S4. The second cover 8 has bulging portions 87, 87' on which the mounting portion AT2 is provided. The bulging portions 87, 87' bulge out in a direction away from the motor case 6 along the rotation axis X1 of the motor M, that is, along the direction in which the rotation axis X1 of the motor M extends. The bulging portion 87 has an expanded space Sa to Sd inside that communicates with the breather chamber S4.

[0127] According to this embodiment, by providing an expanded space Sa to Sd communicating with the breather chamber S4 in the bulging portion 87 which has a mounting portion AT2 to the vehicle body, the weight of the housing HS can be reduced while the volume of the breather chamber S4 can be increased. By increasing the volume of the breather chamber S4, the possibility of oil OL being ejected to the outside of the housing HS from the communication hole 621 provided in the motor case 6 when the pressure inside the housing HS becomes high can be reduced. In this embodiment, it is not necessary to enlarge the housing HS in order to secure the volume of the breather chamber S4, so the mountability of the drive unit 1 on the vehicle V is not impaired due to the enlargement of the housing HS. As a result, a drive unit 1 equipped with a breather chamber S4 and with excellent mountability on the vehicle V can be provided.

[0128] (2) In the power transmission mechanism 3, an intermediate shaft 32 is located between the input shaft 31 to which the rotation of the motor M is input and the drive shafts DS, DS (output shafts) which transmit rotation to the drive wheels WH, WH below the input shaft 31, and the drive shafts DS, DS which transmit rotation. When viewed from the direction of the rotation axis X1 of the motor M, the bulge portion has a bulge portion 87' (first bulge portion) which is located in a position that overlaps with the input shaft 31, and a bulge portion 87 (second bulge portion) which is located on the outer diameter side of the bulge portion 87' and is in a circumferential range around the input shaft 31 (rotation axis X1). The mounting portion AT2 includes a boss portion 88A (first fastening portion) provided at the tip of the bulging portion 87', and a plurality of boss portions 88B to 88E (second fastening portions) provided at the tip of the bulging portion 87, above the boss portion 88A, and positioned at circumferentially offset positions around the rotation axis X1 of the motor M.

[0129] According to this embodiment, the housing HS of the drive unit 1 is fastened to the bracket BK2 by a plurality of fastening parts (first fastening part, second fastening part) on the side of the second cover 8. This improves the support rigidity on the vehicle body side of the second cover 8. Furthermore, the boss parts 88A and 88B to 88E are provided at the tips of bulging parts 87', 87 that protrude in the direction away from the motor case 6 along the rotation axis X1. Therefore, an expanded space Sa to Sd that communicates with the breather chamber R4 can be formed on the base side of the bulging part 87 where the boss parts 88B to 88E are not located. This makes it possible to increase the volume of the space that functions as a breather chamber S4 without increasing the size of the housing HS. In addition, the second cover 8 can be made lighter by removing the material from the bulging part 87 to form the expanded space Sa to Sh. Furthermore, it is preferable that the boss portion 88A is located at the tip of the bulging portion 87' and is positioned concentrically with the input shaft 31 when viewed from the direction of the rotation axis X1, i.e., concentric with the input shaft 31. This shortens the distance from the tip of the input shaft 31 to the tip of the boss portion 88A, thereby suppressing an increase in the size of the housing HS.

[0130] (3) The motor case 6 is provided with a recess in the portion facing the second cover 8, which forms a breather chamber S4 between it and the second cover 8. When viewed from the direction of the rotation axis X1 of the motor M, the second cover 8 has a bulge 87 in the region that overlaps with the recess.

[0131] In the motor case 6, a plurality of ribs 671-676 and 678-681 are provided on the part facing the second cover 8. The area where these ribs 671-681 are provided is a recessed area that is indented towards the back of the paper. This recessed area constitutes part of the breather chamber S4. In this embodiment, the expanded spaces Sa-Sd overlap the recessed area that becomes the breather chamber S4 in the direction of the motor M's rotation axis X1. As a result, when the pressure inside the housing HS increases, a portion of the vaporized oil OL that flows into the breather chamber S4 can be captured in the expanded spaces Sa-Sd, thereby reducing the amount of oil that reaches the communication hole 621 of the breather chamber S4.

[0132] (4) When viewed from the direction of the rotation axis X1 of the motor M, the intermediate shaft 32 is located on one side of the vertical line LV passing through the rotation axis X1 of the motor M. When viewed from the direction of the rotation axis X1 of the motor M, the breather chamber S4 is located above the intermediate shaft 32.

[0133] The idler gear 321 of the intermediate shaft 32, which is located on axis X2, meshes with the input gear 311 of the input shaft 31 on the rotation axis X1, enabling rotational transmission from one side of the vertical line LV passing through the rotation axis X1 of the motor M. Therefore, there is spatial clearance on one side of the vertical line LV, above the intermediate shaft 32. By utilizing this space to provide expansion spaces Sa to Sd, the volume of the breather chamber S4 can be expanded without increasing the size of the housing HS.

[0134] (I) When viewed from the direction of the rotation axis X1 of the motor M, the bulge 87 (second bulge) is arc-shaped along the circumferential direction around the rotation axis X1. One end 871 and the other end 872 of the bulge 87 in the circumferential direction are located below the horizontal line LH1 passing through the boss portion 88A (first fastening portion). When viewed from the direction of the rotation axis X1, the outer diameter of the input gear 311 is smaller than the outer diameter of the motor M. When viewed from the direction of the rotation axis X1, the bulge 87 is arc-shaped along the outer circumference of the input gear 311.

[0135] According to this embodiment, when viewed from the direction of the rotation axis X1, the second cover 8 has sufficient space to provide a bulge 87 on the outer diameter side of the input gear 311 and above the horizontal line LH1. By providing the bulge 87 in this region and also providing boss portions 88B to 88E, both the second cover 8 can be fixed and the breather chamber S4 can be expanded.

[0136] Although embodiments of the present invention have been described above, the present invention is not limited to the embodiments shown. It can be modified as appropriate within the scope of the technical idea of ​​the invention.

[0137] 1: Drive unit, 3: Power transmission mechanism, 31: Input shaft, 32: Intermediate shaft, 6: Motor case (main body), 8: Second cover (cover), 87: Bulge (second bulge), 87': Bulge (first bulge), 88A: Boss (first fastening part), AT (AT to AT4): Mounting part, DS: Drive shaft (output shaft), HS: Housing, M: Motor, S1: First housing chamber, S2: Second housing chamber, S4: Breather chamber, Sa to Sd: Expansion space, WH: Drive wheel

Claims

1. A drive device comprising: a power transmission mechanism for transmitting rotation between a motor and a drive wheel; a housing that houses the motor and the power transmission mechanism and has a breather chamber; and a mounting portion for the vehicle side, wherein the housing has a main body having a first housing chamber for housing the motor; and a cover attached to the main body from the rotation axis direction of the motor and forming a second housing chamber for housing the power transmission mechanism and the breather chamber; the cover has a bulge portion on which the mounting portion is provided; the bulge portion bulges outward from the main body along the rotation axis of the motor and has an expanded space inside the bulge portion that communicates with the breather chamber.

2. The power transmission mechanism according to claim 1, wherein an intermediate shaft for transmitting rotation between the input shaft and the output shaft is located between an input shaft into which the rotation of the motor is input and an output shaft below the input shaft that transmits rotation to the drive wheel, and the bulge portion, viewed from the direction of the rotation axis of the motor, has a first bulge portion located in a position overlapping with the input shaft and a second bulge portion located on the outer diameter side of the first bulge portion in a circumferential range around the input shaft, and the mounting portion has a first fastening portion provided at the tip of the first bulge portion and a plurality of second fastening portions provided at the tip of the second bulge portion, and located above the first fastening portion, with their positions shifted in the circumferential direction around the rotation axis of the motor, the drive device.

3. The drive device according to claim 2, wherein the portion of the main body facing the cover is provided with a recess that forms the breather chamber between itself and the cover, and the cover has the second bulge in a region that overlaps with the recess when viewed from the direction of the rotation axis of the motor.

4. The drive device according to claim 3, wherein, as viewed from the direction of the rotation axis of the motor, the intermediate shaft is located on one side of the vertical line passing through the rotation axis of the motor, and as viewed from the direction of the rotation axis of the motor, the breather chamber is located above the intermediate shaft.

Images