Patent Publication Number: US-2022224200-A1

Title: Vehicle drive device

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is based on and claims priority under 35 USC 119 from Japanese Patent Application No. 2021-003823, filed on Jan. 13, 2021, the contents of which are incorporated herein by reference. 
     TECHNICAL FIELD 
     The present invention relates to a vehicle drive device mounted on a vehicle and, more particularly, to a vehicle drive device including a temperature control circuit. 
     BACKGROUND ART 
     In the related art, there is a vehicle, such as an electric vehicle, on which a vehicle drive device including an electric machine is mounted. In general, since an electric machine generates heat when driven, a vehicle drive device includes a temperature control circuit configured to control a temperature of the electric machine. For example, JP2001-238406A discloses a vehicle drive device including: an electric motor M; and a temperature control circuit including a circulation path L for cooling the electric motor M. 
     The temperature control circuit included in that vehicle drive device includes: the circulation path L through which oil circulates for cooling the electric motor M; a circulation path F through which cooling water circulates for cooling an inverter U; and a heat exchange unit (oil cooler C) configured to exchange heat between the cooling water flowing through the circulation path F and the oil flowing through the circulation path L. A radiator R is provided in the circulation path F, and the cooling water flowing through the circulation path F is cooled by the radiator R. The oil flowing through the circulation path L is cooled by the heat transfer between the cooling water flowing through the circulation path F and the oil flowing through the circulation path L in the heat exchange unit (oil cooler C). Therefore, in that vehicle drive device, a radiator for cooling the oil is not necessary, and the cooling water flowing through the circulation path F and the oil flowing through the circulation path L can be cooled by one radiator, thereby miniaturizing the vehicle drive device. 
     In that vehicle drive device, when the heat exchange unit (oil cooler C) is damaged, the cooling water flowing through the circulation path F for cooling the inverter U may flow into the circulation path L and may enter the oil for cooling the electric motor M. 
     In that vehicle drive device, when the cooling water enters the oil for cooling the electric motor M, the oil containing the cooling water is supplied to the electric motor M. Since water is electrically conductive, a short circuit may occur in the electric motor M. 
     SUMMARY 
     The present invention provides a vehicle drive device capable of preventing a short circuit from occurring even when a conductive temperature-control medium enters a non-conductive temperature-control medium for controlling a temperature of an electric motor. 
     A vehicle drive device according to the present invention includes: 
     a first electric machine: 
     an electric machine housing accommodating the first electric machine; 
     a live part that is provided inside the electric machine housing and is electrically connected to the first electric machine; and 
     a temperature-control circuit for temperature control for the first electric machine, in which 
     the temperature-control circuit includes:
         a first temperature-control circuit through which a non-conductive first temperature-control medium circulates;   a second temperature-control circuit through which a conductive second temperature-control medium circulates; and   a heat exchanger configured to exchange heat between the first temperature-control medium and the second temperature-control medium,       

     at least some of the first temperature-control medium passes inside the electric machine housing for the temperature control for the first electric machine, 
     the first temperature-control circuit includes a dropping pipe that is disposed inside the electric machine housing and above the first electric machine, extends in an axial direction of the first electric machine, and from which the first temperature-control medium drops onto the first electric machine, 
     the live part is provided on a radially outer side of the first electric machine such that the live part overlaps with the first electric machine in the axial direction of the first electric machine, and 
     a protection cover including a first protection wall extending in the axial direction of the first electric machine on the radially outer side of the first electric machine and between the first electric machine and the live part is provided inside the electric machine housing. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1  is a system block diagram of a vehicle drive device according to an embodiment of the present invention. 
         FIG. 2  is an internal view of an interior an electric machine housing in the vehicle drive device of  FIG. 1  as viewed from the left side. 
         FIG. 3  is a perspective view of parts inside the electric machine housing shown in  FIG. 2 . 
         FIG. 4  is an enlarged view around a protection cover shown in  FIG. 2 . 
         FIG. 5  is a perspective view of the protection cover of the vehicle drive device according to an embodiment of the present invention. 
     
    
    
     DESCRIPTION OF EMBODIMENTS 
     In the following, an embodiment of a vehicle on which a vehicle drive device of the present invention is mounted will be described with reference to the drawings. For the sake of convenience, a front-rear (Fr-Rr) direction, a left-right (L-R) direction, and an up-down (U-D) direction refers to directions viewed from a driver of the vehicle. 
     As shown in  FIG. 1 , a vehicle drive device  10  according to the present embodiment includes: an internal combustion engine ICE; an electric motor  20 ; a generator  30 ; a transmission device  40 ; a power conversion device  50 ; and a temperature-control circuit  60  and is mounted on a vehicle V. 
     The electric motor  20  is an electric machine configured to output power for driving the vehicle V using electric power stored in a power storage device (not shown) mounted on the vehicle V or generated by the generator  30 . When the vehicle V brakes, the electric motor  20  may generate electric power from kinetic energy of drive wheels of the vehicle V to charge the power storage device. 
     The generator  30  is an electric machine configured to generate electric power from power of the internal combustion engine ICE mounted on the vehicle V to charge the power storage device or to supply the electric power to the electric motor  20 . 
     Detailed configurations of the electric motor  20  and the generator  30  will be described later. 
     The transmission device  40  is configured to reduce a speed of the electric motor  20  to a speed of the drive wheels and may be a gearbox. 
     The power conversion device  50  includes: a power drive unit (PDU, not shown) configured to convert the electric power output from the power storage device from direct current to alternating current to control input/output power of the electric motor  20  and the generator  30 ; and a voltage control unit (VCU, not shown) configured to step up voltage of the electric power output from the power storage device as necessary. The VCU may step down voltage of the electric power generated by the electric motor  20  when the electric motor  20  generates electric power during the braking of the vehicle V. 
     The temperature-control circuit  60  includes: a first temperature-control circuit  61  through which a non-conductive first temperature-control medium TCM 1  circulates to control temperatures of the electric motor  20 , the generator  30 , and the transmission device  40 ; a second temperature-control circuit  62  through which a conductive second temperature-control medium TCM 2  circulates to control a temperature of the power conversion device  50 ; and a heat exchanger  63  configured to exchange heat between the first temperature-control medium TCM 1  and the second temperature-control medium TCM 2 . The non-conductive first temperature-control medium TCM 1  is, for example, oil called automatic transmission fluid (ATF) capable of lubrication and temperature control for the electric motor  20 , the generator  30 , and the transmission device  40 . The conductive second temperature-control medium TCM 2  is, for example, cooling water called long-life coolant (LLC). 
     The first temperature-control circuit  61  is provided with a first pump  611 . The first pump  611  is, for example, a mechanical pump driven by power of the internal combustion engine ICE and a rotational force of an axle (not shown) of the vehicle V. The first temperature-control circuit  61  includes a branching portion  613 . The first temperature-control circuit  61  includes: a pumping flow path  610   a  in which the first pump  611  is provided, whose upstream end is connected to a storage unit  75  (see  FIG. 2 ) of an electric machine housing  70 , and whose downstream end is connected to the branching portion  613 ; a first branch flow path  610   b   1  in which the electric motor  20  and the generator  30  are provided, whose upstream end is connected to the branching portion  613 , and whose downstream end is connected to the storage unit  75  of the electric machine housing  70 ; and a second branch flow path  610   b   2  in which the transmission device  40  is provided, whose upstream end is connected to the branching portion  613 , and whose downstream end is connected to the storage unit  75  of the electric machine housing  70 . In the first temperature-control circuit  61 , the heat exchanger  63  is disposed upstream from the electric motor  20  and the generator  30 , which are in the first branch flow path  610   bl . Details of the storage unit  75  of the electric machine housing  70  will be described later. 
     Therefore, in the first temperature-control circuit  61 , there are provided in parallel: a flow path in which the first temperature-control medium TCM 1  pumped from the first pump  611  flows through the first branch flow path  610   b   1  via the branching portion  613 , is cooled by the heat transfer with the second temperature-control medium TCM 2  in the heat exchanger  63 , is supplied to the electric motor  20  and the generator  30  for lubrication and temperature control for the electric motor  20  and the generator  30 , and is collected in the storage unit  75  of the electric machine housing  70 ; and a flow path in which the first temperature-control medium TCM 1  pumped from the first pump  611  flows through the second branch flow path  610   b   2  via the branching portion  613 , is supplied to the transmission device  40  for lubrication and temperature control for the transmission device  40 , and is collected in the storage unit  75  of the electric machine housing  70 . The first temperature-control medium TCM 1  collected in the storage unit  75  of the electric machine housing  70  then flows through the pumping flow path  610   a  and is supplied to the first pump  611 , thereby the first temperature-control medium TCM 1  circulating through the first temperature-control circuit  61 . 
     In the present embodiment, the first branch flow path  610   b   1  and the second branch flow path  610   b   2  are formed such that a flow rate of the first temperature-control medium TCM 1  flowing through the first branch flow path  610   b   1  is larger than a flow rate of the first temperature-control medium TCM 1  flowing through the second branch flow path  610   b   2 . 
     The first temperature-control circuit  61  further includes a pressure adjustment circuit  610   c  whose upstream end is connected to the storage unit  75  and whose downstream end is connected to the pumping flow path  610   a  downstream from the first pump  611 . The pressure adjustment circuit  610   c  is provided with a pressure adjustment valve  619 . The pressure adjustment valve  619  may be a check valve or an electrically-actuated valve such as a solenoid valve. When liquid pressure of the first temperature-control medium TCM 1  pumped from the first pump  611  exceed a predetermined upper limit pressure, the pressure adjustment valve  619  is opened to return some of the first temperature-control medium TCM 1  pumped from the first pump  611  to the storage unit  75 . Accordingly, the liquid pressure of the first temperature-control medium TCM 1  flowing through the first branch flow path  610   b   1  and the second branch flow path  610   b   2  is kept below the upper limit pressure. 
     The second temperature-control circuit  62  is provided with a second pump  621 , a radiator  622 , and a storage tank  623 . The second pump  621  is, for example, an electric pump driven by the electric power stored in the power storage device. The radiator  622  is disposed in the front of the vehicle V and is configured to cool the second temperature-control medium TCM 2  using wind raised by traveling of the vehicle V. The storage tank  623  is a tank in which the second temperature-control medium TCM 2  circulating through the second temperature-control circuit  62  is temporarily stored. Even when cavitation occurs in the second temperature-control medium TCM 2  circulating through the second temperature-control circuit  62 , the cavitation disappears as the second temperature-control medium TCM 2  circulating through the second temperature-control circuit  62  is temporarily stored in the storage tank  623 . 
     The second temperature-control circuit  62  includes a branching portion  624  and a merging portion  625 . The second temperature-control circuit  62  includes a pumping flow path  620   a  in which the storage tank  623 , the second pump  621 , and the radiator  622  are provided downstream in this order, whose upstream end is connected to the merging portion  625 , and whose downstream end is connected to the branching portion  624 . The second temperature-control medium TCM 2  stored in the storage tank  623  is pumped by the second pump  621  through the pumping flow path  620   a  and is cooled by the radiator  622 . 
     The second temperature control circuit  62  further includes: a first branch flow path  620   b   1  in which the power conversion device  50  is provided, whose upstream end is connected to the branching portion  624 , and whose downstream end is connected to the merging portion  625 ; and a second branch flow path  620   b   2  in which the heat exchanger  63  is provided, whose upstream end is connected to the branching portion  624 , and whose downstream end is connected to the merging portion  625 . In the present embodiment, a valve device  626  is provided in the second branch flow path  620   b   2  upstream from the heat exchanger  63 . In the present embodiment, the valve device  626  may be an on/off valve configured to switch the second branch flow path  620   b   2  between a fully open state and a fully closed state or a control valve capable of adjusting a flow rate of the second temperature-control medium TCM 2  flowing through the second branch flow path  620   b   2 . 
     Therefore, the second temperature-control medium TCM 2  pumped by the second pump  621  and cooled by the radiator  622  in the pumping flow path  620   a  branches into the first branch flow path  620   b   1  and the second branch flow path  620   b   2  from the branching portion  624 . The second temperature-control medium TCM 2  flowing through the first branch flow path  620   b   1  cools the power conversion device  50  and merges with the second branch flow path  620   b   2  and the pumping flow path  620   a  at the merging portion  625 . The second temperature-control medium TCM 2  flowing through the second branch flow path  620   b   2  cools the first temperature-control medium TCM 1  by heat transfer with the first temperature-control medium TCM 1  in the heat exchanger  63  and merges with the first branch flow path  620   b   1  and the pumping flow path  620   a  at the merging portion  625 . The second temperature-control medium TCM 2  flowing through the first branch flow path  620   b   1  or the second temperature control medium TCM 2  flowing through the second branch flow path  620   b   2  is merged at the merging portion  625 , flows through the pumping flow path  620   a , and is temporarily stored in the storage tank  623 . Then, the second temperature-control medium TCM 2  stored in the storage tank  623  is supplied back to the second pump  621  through the pumping flow path  620   a , thereby the second temperature-control medium TCM 2  circulating through the second temperature-control circuit  62 . 
     In the first temperature-control circuit  61 , after the first temperature-control medium TCM 1  cools the electric motor  20 , the generator  30 , and the transmission device  40 , a temperature of the first temperature control medium TCM 1  stored in the storage unit  75  of the electric machine housing  70  is about 120 [° C.]. The first temperature-control medium TCM 1  of about 100 [° C.] is supplied to the heat exchanger  63 . 
     Meanwhile, in the second temperature-control circuit  62 , a temperature of the second temperature-control medium TCM 2  cooled by the radiator  622  is about 40 [° C.]. Since the second temperature-control medium TCM 2  supplied to the heat exchanger  63  does not pass through the power conversion device  50 , which is a target of temperature control, the second temperature-control medium TCM 2  of about 40 [° C.] is supplied to the heat exchanger  63 . 
     The heat exchanger  63  exchanges heat between the first temperature-control medium TCM 1  of about 100 [° C.] and the second temperature-control medium TCM 2  of about 40 [° C.] that are supplied to the heat exchanger  63 . Then, the first temperature-control medium TCM 1  of about 80 [° C.] is discharged from the heat exchanger  63  to a downstream side of the first branch flow path  610   b   1  of the first temperature control circuit  61 , and the second temperature-control medium TCM 2  of about 70 [° C.] is discharged from the heat exchanger  63  to a downstream side of the second branch flow path  620   b   2  of the second temperature-control circuit  62 . 
     Since the first temperature-control medium TCM 1  is cooled in the heat exchanger  63  in this way, the temperature-control circuit  60  can cool the first temperature-control medium TCM 1  without a radiator dedicated to the first temperature-control medium TCM 1 . Therefore, since the temperature-control circuit  60  can cool the first temperature-control medium TCM 1  flowing through the first temperature-control circuit  61  and the second temperature-control medium TCM 2  flowing through the second temperature-control circuit  62  by one radiator  622 , the temperature-control circuit  60  can be miniaturized. 
     If the first temperature-control medium TCM 1  is ATF, viscosity of the first temperature-control medium TCM 1  increases as a temperature of the first temperature-control medium TCM 1  decreases. If the viscosity increases, friction loss in the electric motor  20  and the generator  30  increases since the first temperature-control medium TCM 1  flows through the electric motor  20  and the generator  30 , and output efficiency of the electric motor  20  and the generator  30  decreases. Therefore, when the electric motor  20  and the generator  30  are not at a high temperature and a temperature of the first temperature-control medium TCM 1  is below a predetermined temperature and the first temperature-control medium TCM 1  does not need to be cooled, for example, when the vehicle V is started, it is preferable that the first temperature-control medium TCM 1  be not cooled. 
     Since the valve device  626  is provided in the second branch flow path  620   b   2  of the second temperature control circuit  62  upstream from the heat exchanger  63 , the valve device  626  can be completely closed to block the second temperature-control medium TCM 2  from flowing through the second branch flow path  620   b   2 . In this case, the second temperature-control medium TCM 2  is not supplied to the heat exchanger  63 . Therefore, heat transfer is not performed between the first temperature-control medium TCM 1  and the second temperature-control medium TCM 2 , and the first temperature-control medium TCM 1  is not cooled. Accordingly, it is possible to prevent the heat exchanger  63  from cooling the first temperature-control medium TCM 1  when the first temperature-control medium TCM 1  does not need to be cooled. 
     As shown in  FIGS. 2 to 4 , the vehicle drive device  10  further includes the electric machine housing  70  in which the electric motor  20 , the generator  30 , and the transmission device  40  are accommodated. 
     The electric motor  20  includes: a substantially annular-shaped rotor  21  configured to rotate around a first rotation axis RC 1  extending horizontally in a vehicle width direction of the vehicle V; and a stator  22  disposed at a predetermined distance in a radial direction from the circumference of the rotor  21 . The stator  22  includes: a substantially annular-shaped stator core  221  having a cylindrical inner surface spaced apart from the circumference of the rotor  21  in the radial direction by a predetermined distance; and a coil  222  that is attached to the stator core  221  and has a substantially annular shape when viewed in an axial direction of the first rotation axis RC 1 , that is, the vehicle width direction of the vehicle V. The stator core  221  is fixed to the electric machine housing  70  with fastening bolts  23  inserted through through holes formed in the stator core  221  and penetrating in the axial direction of the first rotation axis RC 1 . The coil  222  constitutes a three-phase winding of U. V, and W phases. The coil  222  includes a left end portion  222   a  protruding outward in the axial direction of the first rotation axis RC 1  from an end surface of the stator core  221  on one side in the axial direction of the first rotation axis RC 1 . In the present embodiment, the left end portion  222   a  protrudes in the left direction from a left end surface  221   a . Similarly, the coil  222  includes a right end portion  222   b  protruding outward in the axial direction of the first rotation axis RC 1  from another end surface of the stator core  221  on the other side in the axial direction of the first rotation axis RC 1 . In the present embodiment, the right end portion  222   b  protrudes in the right direction from a right end surface  221   b.    
     The generator  30  includes: a substantially annular-shaped rotor  31  configured to rotate around a second rotation axis RC 2  that is extending horizontally in the vehicle width direction of the vehicle V and is parallel to the first rotation axis RC 1 ; and a stator  32  disposed at a predetermined distance in the radial direction from the circumference of the rotor  31 . The second rotation axis RC 2  is anterior to and below the first rotation axis RC 1 . The generator  30  is disposed such that, at least in part, the generator  30  overlaps the electric motor  20  in the axial direction of the first rotation axis RC 1  and the second rotation axis RC 2 , that is, in the vehicle width direction of the vehicle V. The stator  32  includes: a substantially annular-shaped stator core  321  having a cylindrical inner surface radially spaced apart from the circumference of the rotor  31  by a predetermined distance; and a coil  322  that is attached to the stator core  321  and has a substantially annular shape when viewed in the axial direction of the second rotation axis RC 2 , that is, in the vehicle width direction of the vehicle V. The stator core  321  is fixed to the electric machine housing  70  by fastening bolts  33  inserted through through holes formed in the stator core  321  and penetrating in the axial direction of the second rotation axis RC 2 . The coil  322  constitutes a three-phase winding of U, V, and W phases. The coil  322  includes a left end portion  322   a  protruding outward in the axial direction of the second rotation axis RC 2  from an end surface of the stator core  321  on one side in the axial direction of the second rotation axis RC 2 . In the present embodiment, the left end portion  322   a  protrudes in the left direction from a left end surface  321   a  Similarly, the coil  322  includes a right end portion  322   b  protruding outward in the axial direction of the second rotation axis RC 2  from another end surface of the stator core  321  on the other side in the axial direction of the second rotation axis RC 2 . 
     The electric motor  20  is provided with a coil protection member  24  covering the left end portion  222   a  in a circumferential direction at least in part. The coil protection member  24  covers a front lower portion of the left end portion  222   a.    
     The coil protection member  24  includes: a first protection member  241  that is fixed to the stator core  221 , protrudes outward in the axial direction of the first rotation axis RC 1 . that is, protrudes in the left direction from the left end surface  221   a , has a substantially arc shape when viewed in the axial direction of the first rotation axis RC 1 , that is, in the vehicle width direction, and covers an outer surface of a front lower portion of the left end portion  222   a ; and a second protection member  242  that is fixed to the first protection member  241 , has a substantially arc shape extending in the radial direction and the circumferential direction of the first rotation axis RC 1  when viewed in the axial direction of the first rotation axis RC 1 , that is, in the vehicle width direction, and covers a left end surface of a front lower portion of the left end portion  222   a  in the axial direction. 
     The first protection member  241  is formed of, for example, die-cast alloy. Since the first protection member  241  covers the outer surface of the front lower portion of the left end portion  222   a , the first protection member  241  is disposed between the left end portion  222   a  and the left end portion  322   a  of the generator  30  disposed on a front lower side of the electric motor  20 . Therefore, the first protection member  241  prevents the left end portion  322   a  from directly hitting the left end portion  222   a  when strain is put on the electric machine housing  70  from the front to move the generator  30  backward, for example, in case of frontal impact. Accordingly, it is possible to prevent a short circuit by direct contact between the left end portion  322   a  and the left end portion  222   a  from occurring. 
     The second protection member  242  is formed of, for example, a resin. The second protection member  242  covers the left end surface of the front lower portion of the left end portion  222   a  in the axial direction. When strain is put on the electric machine housing  70  to deform or damage the electric machine housing  70 , for example, in case of frontal impact, the second protection member  242  prevents the deformed electric machine housing  70  or broken pieces of the damaged electric machine housing  70  from directly hitting the left end portion  322   a . In this case, the electric motor  20  can be driven by a limp-home mode or the like, and thereby the vehicle V can travel short distance to, for example, a nearby garage or home. 
     Inside the electric machine housing  70 , there are provided: a first dropping pipe  71  disposed above the electric motor  20  and extending in the axial direction of the first rotation axis RC 1 ; and a second dropping pipe  72  disposed above the generator  30  and extending in the axial direction of the second rotation axis RC 2 . In the present embodiment, the first dropping pipe  71  includes two dropping pipes of: a front first dropping pipe  711  that extends in the axial direction of the first rotation axis RC 1  and is anterior to the first rotation axis RC 1 ; and a rear first dropping pipe  712  that extends in the axial direction of the first rotation axis RC 1  and is posterior to the first rotation axis RC 1 . The second dropping pipe  72  includes two dropping pipes of: a front second dropping pipe  721  that extends in the axial direction of the second rotation axis RC 2  and is anterior to the second rotation axis RC 2 ; and a rear second dropping pipe  722  that extends in the axial direction of the second rotation axis RC 2  and is posterior to the second rotation axis RC 2 . 
     In the present embodiment, inside the electric machine housing  70 , there are provided; a first axial pipe  731  extending inside a hollow rotor shaft (not shown) of the electric motor  20  in the axial direction of the first rotation axis RC 1 ; and a second axial pipe  732  extending inside a hollow rotor shaft (not shown) of the generator  30  in the axial direction of the second rotation axis RC 2 . 
     Further, in the present embodiment, there are provided introduction pipes  74  that brings the first temperature-control medium TCM 1  into the electric machine housing  70  and connects the first dropping pipe  71 , the second dropping pipe  72 , the first axial pipe  731 , and the second axial pipe  732 . Therefore, by the introduction pipes  74 , the first temperature control medium TCM 1  is introduced into the rotary electric machine housing  70  from the outside of the rotary electric machine housing  70 , and the first temperature control medium TCM 1  is supplied to the first dropping pipe  71 , the second dropping pipe  72 , the first axial pipe  731 , and the second axial pipe  732 . 
     Therefore, the non-conductive first temperature-control medium TCM 1  flows through the first dropping pipe  71 , the second dropping pipe  72 , the first axial pipe  731 , and the second axial pipe  732 . In this way, the first dropping pipe  71 , the second dropping pipe  72 , the first axial pipe  731 , and the second axial pipe  732  constitute the first branch flow path  610   b   1  of the first temperature-control circuit  61  inside the electric machine housing  70 . 
     On an outer surface of the first dropping pipe  71 , dropping holes  71   a  opened downward are formed along the first rotation axis RC 1 , and the first temperature-control medium TCM 1  flowing through the first dropping pipe  71  drops from the dropping holes  71   a  of the first dropping pipe  71  onto the electric motor  20 . The first temperature control-medium TCM 1  dropping from the dropping holes  71   a  of the first dropping pipe  71  onto the electric motor  20  hits and cools the electric motor  20  and then flows down below the electric motor  20  by gravity. 
     On an outer surface of the second dropping pipe  72 , dropping holes  72   a  opened downward are formed along the second rotation axis RC 2 , and the first temperature-control medium TCM 1  flowing through the second dropping pipe  72  drops from the dropping holes  72   a  of the second dropping pipe  72  onto the generator  30 . The first temperature-control medium TCM 1  dropping from the dropping holes  72   a  of the second dropping pipe  72  on to the generator  30  hits and cools the generator  30  and then flows down below the generator  30  by gravity. 
     On an outer surface of the first axial pipe  731 , supply holes are formed along the first rotation axis RC 1  to supply the first temperature-control medium TCM 1  flowing through the first axial pipe  731  from the supply holes of the first axial pipe  731  to the hollow of the rotor shaft of the electric motor  20 . The first temperature-control medium TCM 1  supplied from the supply holes of the first axial pipe  731  to the hollow of the rotor shaft of the electric motor  20  is supplied to and cools the rotor  21  and the stator  22  and then flows down below the electric motor  20  by gravity. 
     On an outer surface of the second axial pipe  732 , supply holes (not shown) are formed along the second rotation axis RC 2  to supply the first temperature-control medium TCM 1  flowing through the second axial pipe  732  from the supply holes of the second axial pipe  732  to the hollow of the rotor shaft of the generator  30 . The first temperature-control medium TCM 1  supplied from the supply holes of the second axial pipe  732  to the hollow of the rotor shaft of the generator  30  is supplied to and cools the rotor  31  and the stator  32  and then flows down below the generator  30  by gravity. 
     The storage unit  75  is formed in a lower portion of the electric machine housing  70 . The storage unit  75  is formed below the generator  30  when viewed in the vehicle width direction and is formed such that the storage unit  75  overlaps the generator  30  in the front-rear direction at least in part. The first temperature-control medium TCM 1  is stored in the storage unit  75 . The first temperature-control medium TCM 1  that drops from the first dropping pipe  71 , cools the electric motor  20 , and flows down below the electric motor  20  by gravity is collected in the storage unit  75 . The first temperature control-medium TCM 1  that drops from the second dropping pipes  72 , cools the generator  30 , and flows down below the generator  30  by gravity is collected in the storage unit  75 . The first temperature control medium TCM 1  that is supplied from the first axial pipe  731 , cools the electric motor  20 , and flows down below the electric motor  20  by gravity is collected in the storage unit  75 . The first temperature control medium TCM 1  that is supplied from the second axial pipe  732 , cools the generator  30 , and flows down below the generator  30  by gravity is collected in the storage unit  75 . 
     The generator  30  is immersed in the first temperature-control medium TCM 1  stored in the storage unit  75  at least in part. More specifically, in the generator  30 , the rotor  31  is immersed in the first temperature-control medium TCM 1  stored in the storage unit  75  at least in part. Therefore, when the generator  30  is driven, the first temperature control-medium TCM 1  stored in the storage unit  75  is scooped up by the rotating rotor  31  and is sprinkled inside the electric machine housing  70  for temperature control for the electric motor  20 , the generator  30 , the transmission device  40 , and the like. Accordingly, temperature-control performance of the vehicle drive device  10  is improved. 
     In this way, in the first temperature control circuit  61 , at least the first dropping pipe  71 , the second dropping pipe  72 , the first axial pipe  731 , the second axial pipe  732 , and the introduction pipes  74  pass through inside the electric machine housing  70  for temperature control for the electric motor  20 , the generator  30 , and the transmission device  40 . 
     A live part  80  is provided inside the electric machine housing  70 . The live part  80  includes a connector unit  81 , a terminal block  82 , and a bus bar unit  83 . The live part  80  is provided on a radially outer side of the electric motor  20  and the generator  30  such that the live part  80  overlaps with the electric motor  20  and the generator  30  in the axial direction of the first rotation axis RC 1  and the second rotation axis RC 2 , that is, in the vehicle width direction. The live part  80  is disposed anterior to the electric motor  20  and above the generator  30 . The live part  80  is disposed such that the live part  80  overlaps with the electric motor  20  in the up-down direction at least in part and with the generator  30  in the front-rear direction at least in part. That is, the generator  30  is located below the live part  80  when viewed in the vehicle width direction such that the generator  30  overlaps with the live part  80  in the front-rear direction at least in part. 
     The connector unit  81  includes: a first terminal unit  811  including three terminals of  811 U for the U phase,  811 V for the V phase, and  811 W for the W phase; and a second terminal unit  812  including three terminals of  812 U for the U phase,  812 V for the V phase, and  812 W for the W phase. The connector unit  81  further includes a six-phase connector unit  813  electrically connected to the six terminals of the three terminals  811 U,  811 V, and  811 W of the first terminal unit  811  and the three terminals  812 U,  812 V, and  812 W of the second terminal unit  812 . The six-phase connector unit  813  is electrically connected to the six terminals of the three terminals  811 U,  811 V, and  811 W of the first terminal unit  811  and the three terminals  812 U,  812 V, and  812 W of the second terminal unit  812  by bus bars (not shown). The six-phase connector unit  813  is electrically connected to the power conversion device  50  by a cable harness, a bus bar, or the like. 
     In the present embodiment, the first terminal unit  811  is disposed on the left of the second terminal unit  812  in the vehicle width direction, and the three terminals of  811 U for the U phase,  811 V for the V phase, and  811 W for the W phase are disposed abreast in the front-rear direction of the vehicle V. The second terminal unit  812  is disposed on the right of the first terminal unit  811  in the vehicle width direction similarly to the first terminal unit  811  in the front-rear direction, and the three terminals of  812 U for the U phase,  812 V for the V phase,  812 W for the W phase are disposed abreast in the front-rear direction of the vehicle V. The second terminal unit  812  is located below the first terminal unit  811 . 
     The terminal block  82  includes three terminals of  821 U for the U phase,  821 V for the V phase, and  821 W for the W phase. 
     The bus bar unit  83  includes three bus bars of  83 U for the U phase,  83 V for the V phase, and  83 W for the W phase. The bus bar  83 U for the U phase connects the terminal  812 U for the U phase of the second terminal unit  812  of the connector unit  81  and the terminal  821 U for the U phase of the terminal block  82 . The bus bar  83 V for the V phase connects the terminal  812 V for the V phase of the second terminal unit  812  of the connector unit  81  and the terminal  821 V for the V phase of the terminal block  82 . The bus bar  83 W for the W phase connects the terminal  812 W for the W phase of the second terminal unit  812  of the connector unit  81  and the terminal  821 W for the V phase of the terminal block  82 . 
     Inside the electric machine housing  70 , there are provided: first wiring members  761 U for the U phase electrically connecting the terminal  811 U for the U phase of the first terminal unit  811  and winding for the U phase of the coil  222 ;  761 V for the V phase electrically connecting the terminal  81   l V for the V phase of the first terminal unit  811  and winding for the V phase of the coil  222 ; and  761 W for the W phase electrically connecting the terminal  811 W for the W phase of the first terminal unit  811  and winding for the W phase of the coil  222 . An end of the first wiring members  761 U,  761 V, and  761 W is connected to the three terminals  811 U.  811 V, and  811 W of the first terminal unit  811 , and the other end is connected to the windings of the coil  222 . 
     Inside the electric machine housing  70 , there are provided: second wiring members  762 U for the U phase electrically connecting the terminal  821 U for the U phase of the terminal block  82  and winding for the U phase of the coil  322 ;  762 V for the V phase electrically connecting the terminal  821 V for the V phase of the terminal block  82  and winding for the V phase of the coil  322 ; and  762 W for the W phase electrically connecting the terminal  821 W for the W phase of the terminal block  82  and winding for the W phase of the coil  322 . An end of the second wiring members  762 U,  762 V, and  762 W is connected to the three terminals  821 U,  821 V, and  821 W of the generator terminal block  82 , and the other end is connected to the windings of the coil  322 . 
     Therefore, the windings of the coil  222  are electrically connected to the power conversion device  50  via the first wiring members  761 U,  761 V, and  761 W and the connector unit  81  of the live part  80 . The windings of the coil  322  are electrically connected to the power conversion device  50  via the second wiring members  762 U,  762 V, and  762 W, the bus bar unit  83 , and the connector unit  81  of the live part  80 . Input/output power of the electric motor  20  and the generator  30  are controlled by the power conversion device  50 . 
     A protection cover  90  covering the live part  80  is further provided inside the electric machine housing  70 . The protection cover  90  is formed of a non-conductive material, for example, a resin. 
     As shown in  FIGS. 4 and 5 , the protection cover  90  includes: a first protection wall  91  extending in the axial direction of the first rotation axis RC 1  and in the up-down direction in the radially outer side of the electric motor  20  and between the electric motor  20  and the live part  80  to cover a rear side of the live part  80 ; a second protection wall  92  extending in the up-down direction and in the front-rear direction to cover a left side of the live part  80  in the vehicle width direction; and a third protection wall  93  extending in the axial direction of the first rotation axis RC 1  and in the up-down direction in front of the live part  80  to cover a front side of the live part  80 . In the protection cover  90 , the first protection wall  91 , the second protection wall  92 , and the third protection wall  93  are integrally formed. The first protection wall  91  is connected to a rear end portion of the second protection wall  92  and extends toward a right side in the vehicle width direction. The third protection wall  93  is connected to a front end portion of the second protection wall  92  and extends toward the right side in the vehicle width direction. 
     In the present embodiment, the first protection wall  91  extends in the axial direction of the first rotation axis RC 1  and the up-down direction, and a middle portion of the first protection wall  91  in the up-down direction has a shape curved and recessed forward along the stator core  221  when viewed in the vehicle width direction. The second protection wall  92  extends in the up-down direction and the front-rear direction, and a middle portion of the second protection wall in the up-down direction has a shape protruding outward in the vehicle width direction, that is, protruding in the left direction. 
     In the temperature-control circuit  60 , if the heat exchanger  63  is damaged, some of the second temperature-control medium TCM 2  flowing through the second temperature-control circuit  62  may flow into the first temperature-control circuit  61 , through which the first temperature-control medium TCM 1  flows, and the conductive second temperature-control medium TCM 2  may enter the non-conductive first temperature-control medium TCM 1 . If the conductive second temperature-control medium TCM 2  enters the non-conductive first temperature-control medium TCM 1 , the first temperature-control medium TCM 1  containing the second temperature-control medium TCM 2  may scatter from the electric motor  20  and adhere to the live part  80 . In this case, since the second temperature-control medium TCM 2  is electrically conductive, a short circuit may occur, for example, among the terminals  811 U,  811 V, and  811 W of the first terminal unit  811 . 
     In the present embodiment, since the protection cover  90  includes the first protection wall  91  extending in the axial direction of the first rotation axis RC 1  and the up-down direction in the radially outer side of the electric motor  20  and between the electric motor  20  and the live part  80  to cover the rear side of the live part  80 , even when the conductive second temperature-control medium TCM 2  enters the non-conductive first temperature-control medium TCM 1  for temperature control for the electric motor  20 , the first protection wall  91  can prevent the first temperature-control medium TCM 1  containing the conductive second temperature-control medium TCM 2  from scattering from the electric motor  20  to adhere to the live part  80 . Accordingly, even when the conductive second temperature-control medium TCM 2  enters the non-conductive first temperature-control medium TCM 1  for temperature control for the electric motor  20 , the short circuit can be prevented from occurring. 
     In an upper portion of the second protection wall, an opening  921  in the vehicle width direction is formed. Through the opening  921 , the first wiring members  761 U,  761 V, and  761 W electrically connecting the terminals  811 U,  811 V, and  811 W of the first terminal unit  811  of the live part  80  and the windings of the coil  222  of the electric motor  20  are inserted. 
     A lower side of the live part  80  is not covered with the protection cover  90 . The second wiring members  762 U,  762 V, and  762 W extend upward from the coil  322  of the generator  30  through the lower side of the live part  80  not covered by the protection cover  90  toward the terminals  821 U,  821 V.  821 W of the terminal block  82  of the live part  80 . 
     As described above, when the generator  30  is driven, the first temperature-control medium TCM 1  stored in the storage unit  75  is scooped up by the rotating rotor  31  and is sprinkled inside the electric machine housing  70 . Since the outer surface of the rotor  31  is covered with the stator  32 , the first temperature-control medium TCM 1  scooped up by the rotor  31  is mainly sprinkled from both end surfaces of the rotor  31  in the axial direction. 
     In the present embodiment, since the protection cover  90  includes the second protection wall  92  extending in the up-down direction and in the front-rear direction and covering the left side of the live part  80  in the vehicle width direction, the second protection wall  92  can prevent the first temperature-control medium TCM 1  that is scooped up by the rotor  31  and is sprinkled from the end surface of the rotor  31  in the axial direction on the left side in the vehicle width direction from adhering to the live part  80  from the left side in the vehicle width direction. 
     Therefore, even when the conductive second temperature-control medium TCM 2  enters the non-conductive first temperature control medium TCM 1  and the first temperature-control medium TCM 1  in the storage unit  75  containing the second temperature-control medium TCM 2  is scooped up by the rotating rotor  31  and is sprinkled inside the electric machine housing  70 , it is possible to prevent the first temperature-control medium TCM 1  containing the conductive second temperature-control medium TCM 2  from adhering to the live part  80 . Accordingly, the short circuit can be prevented from occurring. 
     The protection cover  90  is provided with a guiding inclined portion  911  that protrudes from the first protection wall  91  toward the electric motor  20  and extends in the up-down direction and in the vehicle width direction (the axial direction of the first rotation axis RC 1 ). In the present embodiment, when viewed in the vehicle width direction, the guiding inclined portion  911  protrudes rearward from the first protection wall  91 , slants downward from front to rear, and extends in the up-down direction and in the vehicle width direction (the axial direction of the first rotation axis RC 1 ). 
     Therefore, the first temperature control medium TCM 1  that is sprinkled from the electric motor  20  and adheres to the first protection wall  91  above the guiding inclined portion  911  of the protection cover  90  flows downward along the first protection wall  91  and the guiding inclined portion  911  by gravity and is discharged toward the electric motor  20  from an end portion  911   a  of the guiding inclined portion  911 . Accordingly, the first temperature-control medium TCM 1  adhering to the first protection wall  91  above the guiding inclined portion  911  of the protection cover  90  can be supplied back to the electric motor  20  from the end portion  911   a  of the guiding inclined portion  911  for temperature control for the electric motor  20 , and thereby enabling more efficient temperature control for the electric motor  20 . 
     Most of the first temperature-control medium TCM 1  dropping from the first dropping pipe  71  flows along an outer surface of the substantially annular-shaped left end portion  222   a . When the first temperature-control medium TCM 1  dropping from the front first dropping pipe  711  and flowing along an outer surface of a front upper portion of the left end portion  222   a  reaches a front end surface of the left end portion  222   a , the first temperature-control medium TCM 1  flows downward in the up-down direction by gravity. Therefore, it is difficult to supply the first temperature-control medium TCM 1  to the front lower portion of the left end portion  222   a  for temperature control. 
     In the present embodiment, when viewed in the vehicle width direction, the end portion  911   a  of the guiding inclined portion  911  is formed such that the end portion  911   a  overlaps with an upper end portion  24   a  of the coil protection member  24  in the front-rear direction above the coil protection member  24 . 
     Therefore, the first temperature-control medium TCM 1  supplied from the end portion  911   a  of the guiding inclined portion  911  toward the electric motor  20  is supplied from the upper end portions  24   a  of the coil protection member  24  to a space surrounded by the coil protection member  24  and the left end surface  221   a  of the stator core  221 . Then, the first temperature control-medium TCM 1  supplied to the space flows inside the space along the left end portion  222   a  for temperature control for the front lower portion of the left end portion  222   a  and is discharged from a lower end portion of the coil protection member  24  to an outside of the space. Accordingly, more efficient temperature control for the left end portion  222   a  can be achieved. In particular, the first temperature-control medium TCM 1  can be supplied to the front lower portion of the left end portion  222   a , for which appropriate temperature control is difficult. 
     The first protection wall  91  is formed, when viewed in the vehicle width direction, such that a lower end portion  91   a  of the first protection wall  91  overlaps the generator  30  in the front-rear direction. 
     Therefore, the first temperature-control medium TCM 1  that is returned from the end portion  911   a  of the guiding inclined portion  911  to the first protection wall  91  below the guiding inclined portion  911  or that is sprinkled from the electric motor  20  and adheres to the first protection wall  91  below the guiding inclined portion  911  of the protection cover  90  flow downward along the first protection wall  91  by gravity and drops from the lower end portion  91   a  of the first protection wall  91  onto the generator  30 . Accordingly, a larger amount of the first temperature-control medium TCM 1  can be used, more efficient temperature control for the generator  30  can be achieved. 
     A lower edge portion  921   a  of the opening  921  formed in the second protection wall  92  is provided with an opening protection wall  922  protruding from the second protection wall  92  in the left direction, that is, in a direction away from the live part  80  in the vehicle width direction. In the present embodiment, the opening protection wall  922  is bent upward from a front end of the lower edge portion  921   a  of the opening  921  to extend to a front edge portion  921   b  of the opening  921  and is bent upward from a rear end of the lower edge portion  921   a  of the opening  921  to extend to a rear edge portion  921   c  of the opening  921 . Therefore, the opening protection wall  922  protrudes from the second protection wall  92  in the left direction at the lower edge portion  921   a , the front edge portion  921   b , and the rear edge portion  921   c  of the opening  921  and has a substantially U-shaped when viewed from the vehicle width direction. 
     Therefore, the opening protection wall  922  can prevent the first temperature-control medium TCM 1  that is scooped up by the rotor  31  and is sprinkled from the end surface in the axial direction on the left side in the vehicle width direction of the rotor  31  from entering, from the opening  921 , the space in which the live part  80  is disposed. Accordingly, even when the conductive second temperature-control medium TCM 2  enters the non-conductive first temperature-control medium TCM 1  and the first temperature-control medium TCM 1  in the storage unit  75  containing the second temperature-control medium TCM 2  is scooped up by the rotating rotor  31  and is sprinkled inside the electric machine housing  70 , it is possible to prevent the first temperature control medium TCM 1  containing the conductive second temperature control medium TCM 2  from entering from the opening  921  and adhering to the live part  80 , and the short circuit can be prevented from occurring. 
     According to the present invention, the protection cover including: the first protection wall extending in the axial direction of the first electric machine in the radially outer side of the first electric machine and between the first electric machine and the live part. Even when the conductive second temperature-control medium enters the non-conductive first temperature-control medium for temperature control for the first electric machine, the first protection wall can prevent the first temperature-control medium containing the conductive second temperature-control medium from being sprinkled from the first electric machine and adhering to the live part. Accordingly, even when the conductive second temperature-control medium enters the non-conductive first temperature-control medium for temperature control for the first electric machine, a short circuit can be prevented from occurring. 
     Although an embodiment of the present invention has been described above with reference to the drawings, it goes without saying that the present invention is not limited thereto. It is obvious to those skilled in the art that various changes or modifications can be conceived within the scope of the claims, and it is understood that the various changes or modifications belong to the technical scope of the present invention. The components in the embodiment described above can be combined arbitrarily within the gist of the invention. 
     For example, in the present embodiment, the electric motor  20  has the first rotation axis RC 1 , and the generator  30  has the second rotation axis RC 2  that extends horizontally in the vehicle width direction of the vehicle V, is parallel to the first rotation axis RC 1 , and is anterior to and below the first rotation axis RC 1 . However, positions of the electric motor  20  and the generator  30  may be reversed. That is, the generator  30  may have the first rotation axis RC 1 , and the electric motor  20  may have the second rotation axis RC 2  that extends horizontally in the vehicle width direction of the vehicle V, is parallel to the first rotation axis RC 1 , and is anterior to and below the first rotation axis RC 1 . 
     For example, in the present embodiment, the first rotation axis RC 1  and the second rotation axis RC 2  extend horizontally in the vehicle width direction. However, the first rotation axis RC 1  and the second rotation axis RC 2  may extend horizontally in the front-rear direction of the vehicle V. 
     In the present specification, at least the following are described. In the parentheses, the corresponding components and the like in the above-described embodiment are shown as an example. However, the present invention is not limited thereto. 
     (1) A vehicle drive device (vehicle drive device  10 ) includes: 
     a first electric machine (electric motor  20 ); 
     an electric machine housing (electric machine housing  70 ) accommodating the first electric machine: 
     a live part (live part  80 ) that is provided inside the electric machine housing and is electrically connected to the first electric machine; and 
     a temperature-control circuit (temperature-control circuit  60 ) for temperature control for the first electric machine, in which 
     the temperature-control circuit includes:
         a first temperature-control circuit (first temperature-control circuit  61 ) through which a non-conductive first temperature-control medium (first temperature-control medium TCM 1 ) circulates;   a second temperature-control circuit (second temperature-control circuit  62 ) through which a conductive second temperature-control medium (second temperature-control medium TCM 2 ) circulates; and   a heat exchanger (heat exchanger  63 ) configured to exchange heat between the first temperature-control medium and the second temperature-control medium,       

     at least some of the first temperature-control medium passes inside the electric machine housing for the temperature control for the first electric machine, 
     the first temperature-control circuit includes a dropping pipe (first dropping pipe  71 ) that is disposed inside the electric machine housing and above the first electric machine, extends in an axial direction of the first electric machine, and from which the first temperature-control medium drops onto the first electric machine, 
     the live part is provided on a radially outer side of the first electric machine such that the live part overlaps with the first electric machine in the axial direction of the first electric machine, and 
     a protection cover (protection cover  90 ) including a first protection wall (first protection wall  91 ) extending in the axial direction of the first electric machine on the radially outer side of the first electric machine and between the first electric machine and the live part is provided inside the electric machine housing. 
     According to (1), the protection cover including: the first protection wall extending in the axial direction in the radially outer side and between the first electric machine and the live part. Even when the conductive second temperature-control medium enters the non-conductive first temperature-control medium, the first protection wall can prevent the first temperature-control medium containing the conductive second temperature-control medium from being sprinkled from the first electric machine and adhering to the live part. Accordingly, even when the conductive second temperature-control medium enters the non-conductive first temperature-control medium, a short circuit can be prevented from occurring. 
     (2) The vehicle drive device according to (1), in which 
     the protection cover is provided with a guiding inclined portion (guiding inclined portion  911 ) that protrudes from the first protection wall toward the first electric machine and extends in an up-down direction and in the axial direction of the first electric machine. 
     According to (2), the protection wall is provided with the guiding inclined portion that protrudes from the first protection wall toward the first electric machine and extends in the up-down direction and in the axial direction. Since the first temperature-control medium that is sprinkled from the first electric machine and adheres to the first protection wall above the guiding inclined portion can be supplied back to the first electric machine from the end portion for temperature control for the first electric machine. Accordingly, more efficient temperature control for the first electric machine can be achieved. 
     (3) The vehicle drive device according to (2), in which 
     the axial direction of the first electric machine extends horizontally in a first direction (vehicle width direction), 
     the first electric machine includes:
         the substantially annular-shaped first rotor (rotor  21 ); and   the first stator (stator  22 ) disposed at a predetermined distance in the radial direction from an outer surface of the first rotor,       

     the first stator includes: a first stator core (stator core  221 ); and a first coil (coil  222 ) that is attached to the first stator core and has a substantially annular shape when viewed in the axial direction of the first electric machine, 
     the first coil includes a first coil end portion (left end portion  222   a ) protruding outward in the axial direction of the first electric machine from a first stator core end surface (left end surface  221   a ) that is an end surface of the first stator core on one side in the axial direction of the first electric machine, 
     the first electric machine is provided with a coil protection member (coil protection member  24 ) covering the first coil end portion at least in part in a circumferential direction, and 
     the guiding inclined portion is formed, when viewed from the first direction, such that an end portion (end portion  911   a ) of the guiding inclined portion overlaps with an upper end portion (upper end portions  24   a ) of the coil protection member above the coil protection member in a second direction (front-rear direction) perpendicular to both the up-down direction and the first direction. 
     According to (3), since the guiding inclined portion is formed, when viewed from the first direction, such that the end portion of the guiding inclined portion overlaps with the upper end portion of the coil protection member above the coil protection member in the second direction, the first temperature-control medium supplied from the end portion of the guiding inclined portion toward the first electric machine is supplied from the upper end portions of the coil protection member to a space surrounded by the coil protection member and the first stator core end surface. Then, the first temperature-control medium supplied to the space flows inside the space along the first coil end portion for temperature control for the first coil end portion. Thus, more efficient temperature control for the first coil end portion can be achieved. 
     (4) The vehicle drive device according to (1), in which 
     the second electric machine (generator  30 ) is accommodated in the electric machine housing, 
     both the axial direction of the first electric machine and an axial direction of the second electric machine extend horizontally in the first direction (vehicle width direction), 
     the storage unit (storage unit  75 ) in which the first temperature-control medium is stored is formed in a lower portion of the electric machine housing, 
     the second electric machine is disposed below the live part when viewed from the first direction such that the second electric machine overlaps with the live part in a second direction (front-rear direction) perpendicular to both the up-down direction and the first direction at least in part, 
     the second electric machine is immersed in the first temperature-control medium stored in the storage unit at least in part, and 
     the protection cover includes a second protection wall (second protection wall  92 ) extending in the up-down direction and in the second direction to cover one side of the live part in the first direction at least in part. 
     According to (4), since the protection cover includes the second protection wall extending in the up-down direction and in the second direction to cover one side of the live part in the first direction at least in part, the second protection wall can prevent the first temperature-control medium scooped up from the storage unit by the second electric machine from adhering to the live part. Accordingly, even when the conductive second temperature-control medium enters the non-conductive first temperature-control medium, a short circuit can be prevented from occurring. 
     (5) The vehicle drive device according to (4), in which 
     the second protection wall has an opening (opening  921 ) in the first direction into which a first wiring member (first wiring members  761 U,  761 V, and  761 W) configured to electrically connect the live part and the first electric machine is inserted, and 
     an opening protection wall (opening protection wall  922 ) protruding from the second protection wall in a direction away from the live part in the first direction is provided at a lower edge portion (lower edge portion  921   a ) of the opening. 
     According to (5), since the opening protection wall protruding from the second protection wall in the direction away from the live part is provided at the lower edge portion, the opening protection wall can prevent the first temperature-control medium that is scooped up by the second electric machine from the storage unit from entering, from the opening, the space in which the live part is disposed. Accordingly, even when the conductive second temperature-control medium enters the non-conductive first temperature-control medium, the first temperature-control medium containing the conductive second temperature-control medium can be prevented from entering from the opening and adhering to the live part, and a short circuit can be prevented from occurring.