Patent Publication Number: US-2022213957-A1

Title: Vehicle drive device

Description:
TECHNICAL FIELD 
     The present disclosure relates to vehicle drive devices including: an input member that is drivingly coupled to an internal combustion engine; a pair of output members that is drivingly coupled to wheels; a first rotating electrical machine and a second rotating electrical machine; a first transmission system that drivingly couples the first rotating electrical machine and the input member; a second transmission system that drivingly couples the second rotating electrical machine and the pair of output members; and a first hydraulic pump and a second hydraulic pump. 
     BACKGROUND ART 
     An example of such a vehicle drive device is disclosed in Patent Document 1 below. In the following description of the background art, reference signs in Patent Document 1 are shown in parentheses. 
     A vehicle drive device of Patent Document 1 includes a first hydraulic pump (101) that is driven by a driving force of an internal combustion engine (1) transmitted to an input member (6), and a second hydraulic pump (102) that is driven by a dedicated driving force source (111), the dedicated driving force source (111) being independent of a first transmission system (5) and a second transmission system (11, 8, 9). The first hydraulic pump (101) is configured to supply oil to the first rotating electrical machine (2), the second rotating electrical machine (3), and the first transmission system (5) through oil passages (210, 220, 230). The second hydraulic pump (102) is configured to supply oil to the second rotating electrical machine (3) through an oil passage (240). 
     RELATED ART DOCUMENTS 
     Patent Documents 
     Patent Document 1: Japanese Unexamined Patent Application Publication No. 2017-61226 (JP 2017-61226 A) (FIG. 3) 
     SUMMARY OF THE INVENTION 
     Problem to be Solved by the Disclosure 
     In the vehicle drive device of Patent Document 1, neither the first hydraulic pump (101) nor the second hydraulic pump (102) supply oil to the second transmission system (11, 8, 9), and oil is supplied to the second transmission system (11, 8, 9) by rotation of an input gear (9 a ) of a differential gear mechanism (9) included in the second transmission system (11, 8, 9). Specifically, oil stored in a case (30) is scooped up by rotation of the input gear (9 a ) of the differential gear mechanism (9), and this oil flows through oil passages provided in various portions in the case (30) due to the action of gravity and is supplied to each part of the second transmission system (11, 8, 9). In such a configuration in which oil is supplied using gear rotation, oil supply paths and the flow rate of oil in each path tend to be affected by the mounting angle of the vehicle drive device on the vehicle, the sizes of the components of the second transmission system (11, 8, 9), etc. It is therefore difficult to use the same vehicle drive device to a plurality of vehicle models, and the vehicle drive device lacks robustness because of, e.g., the need to redesign the oil passages for each vehicle model. 
     A first possible method to solve the above problem is to configure the first hydraulic pump (101) to supply oil to the second transmission system (11, 8, 9) in addition to the first rotating electrical machine (2), the second rotating electrical machine (3), and the first transmission system (5). A second possible method is to configure the second hydraulic pump (102) to supply oil to the second transmission system (11, 8, 9) in addition to the second rotating electrical machine (3). 
     In the first method, however, when the internal combustion engine (1) is stopped and the vehicle is traveling by the driving force of the second rotating electrical machine (3), the first hydraulic pump (101) is not driven and therefore oil cannot be supplied to the second transmission system (11, 8, 9). In the second method, on the other hand, oil can be supplied to the second transmission system (11, 8, 9) regardless of the state of the internal combustion engine (1). However, when the internal combustion engine (1) is stopped and the vehicle is traveling by the driving force of the second rotating electrical machine (3), the first hydraulic pump (101) is not driven and therefore oil cannot be supplied to the first transmission system (5). Accordingly, in the second method, the discharge amount of the second hydraulic pump (102) needs to be large enough so that the second hydraulic pump (102) can supply oil to the first transmission system (5) in addition the second rotating electrical machine (3) and the second transmission system (11, 8, 9). This results in increased manufacturing cost of the vehicle drive device. 
     It is therefore desired to implement a vehicle drive device with high robustness and low manufacturing cost. 
     Means for Solving the Problem 
     In view of the above, the vehicle drive device is characterized by including: 
     an input member that is drivingly coupled to an internal combustion engine;
         an output member that is drivingly coupled to wheels;       

     a first rotating electrical machine and a second rotating electrical machine;
         a first transmission system that drivingly couples the first rotating electrical machine and the input member;   a second transmission system that drivingly couples the second rotating electrical machine and the output member;   a first hydraulic pump that is driven by a driving force transmitted through the second transmission system;   a second hydraulic pump that is driven by a dedicated driving force source, the dedicated driving force source being independent of the first transmission system and the second transmission system;   a first oil passage that supplies oil discharged from the first hydraulic pump to the second transmission system;   a second oil passage that supplies oil discharged from the second hydraulic pump to the first transmission system;   a third oil passage that supplies the oil discharged from the second hydraulic pump to the first rotating electrical machine; and       

     a fourth oil passage that supplies the oil discharged from the second hydraulic pump to the second rotating electrical machine. 
     According to this characteristic configuration, oil is supplied to the second transmission system by the first hydraulic pump that is driven by the driving force transmitted through the second transmission system that drivingly couples the second rotating electrical machine and the output member. Accordingly, oil can be appropriately supplied to the portion to which the driving force is transmitted when the vehicle is traveling by the driving force of the second rotating electrical machine. Oil is also supplied to the first transmission system, the first rotating electrical machine, and the second rotating electrical machine by the second hydraulic pump that is driven by the independent dedicated driving force source. Accordingly, when the vehicle is traveling by the driving force of the second rotating electrical machine, the second rotating electrical machine can be cooled by the oil discharged from the second hydraulic pump. When the first rotating electrical machine generates electric power by the driving force of the internal combustion engine while the vehicle is stopped, the first transmission system can be lubricated and the first rotating electrical machine can be cooled both by the oil discharged from the second hydraulic pump. That is, by controlling the discharge amount of the second hydraulic pump, an appropriate amount of oil can be supplied to the portions where oil is needed according to the operating state of each part, regardless of the traveling state of the vehicle. 
     As described above, according to this configuration, the oil discharged from the first hydraulic pump and the second hydraulic pump can be appropriately supplied to the portions of the vehicle drive device where oil is needed, without using gear rotation. Oil can thus be stably supplied to each part regardless of the mounting angle of the vehicle drive device on the vehicle, the sizes of the components of the second transmission system, etc. Therefore, according to this configuration, the vehicle drive device with high robustness can be implemented. 
     According to this configuration, even while the internal combustion engine is stopped, oil is supplied to the second transmission system by the first hydraulic pump that is driven by the driving force transmitted through the second transmission system that drivingly couples the second rotating electrical machine and the output member, when the vehicle is traveling by the driving force of the second rotating electrical machine. That is, even while the internal combustion engine is stopped, the second transmission system can be lubricated by the oil discharged from the first hydraulic pump. The discharge amount of the second hydraulic pump therefore need not be large enough that the second hydraulic pump that is driven by the independent dedicated driving force source can supply oil to the second transmission system in addition the first rotating electrical machine, the second rotating electrical machine, and the first transmission system. As a result, manufacturing cost of the vehicle drive device can be reduced. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a skeleton diagram of a vehicle drive device according to a first embodiment. 
         FIG. 2  is a conceptual diagram illustrating a hydraulic circuit of the vehicle drive device according to the first embodiment. 
         FIG. 3  is a skeleton diagram of a vehicle drive device according to a second embodiment. 
         FIG. 4  is a skeleton diagram of a vehicle drive device according to a third embodiment. 
         FIG. 5  is a conceptual diagram illustrating a hydraulic circuit of the vehicle drive device according to the third embodiment. 
     
    
    
     MODES FOR CARRYING OUT THE DISCLOSURE 
     1. First Embodiment 
     Hereinafter, a vehicle drive device  100  according to a first embodiment will be described with reference to the drawings. As shown in  FIG. 1 , the vehicle drive device  100  includes a first rotating electrical machine MG 1  and a second rotating electrical machine MG 2 , a first transmission system T 1  and a second transmission system T 2 , an input member  1 , and an output member  5 . In the present embodiment, these components are housed in a case (not shown). 
     The first transmission system T 1  drivingly couples the first rotating electrical machine MG 1  and the input member  1 . The second transmission system T 2  drivingly couples the second rotating electrical machine MG 2  and the output member  5 . In the present embodiment, the first transmission system T 1  includes a first planetary gear mechanism PG 1 . Further, in the present embodiment, the second transmission system T 2  includes a second planetary gear mechanism PG 2 , a counter drive gear  2 , a counter gear mechanism  3 , and a differential gear mechanism  4 . 
     As used herein, “drivingly coupled” refers to the state where two rotation elements are coupled so that a driving force can be transmitted therebetween, and includes the state where the two rotation elements are coupled so as to rotate integrally or the state where the two rotation elements are coupled via one or two or more transmission members so that a driving force can be transmitted therebetween via the one or more transmission members. Such transmission members include various members that transmit rotation at the same speed or at a shifted speed, such as, e.g., a shaft, a gear mechanism, a belt, and a chain. The transmission members may include an engagement device that selectively transmits rotation and a driving force, such as, e.g., a friction engagement device and a meshing engagement device. In the case where “drivingly coupled” is used for each rotation element in the first planetary gear mechanism PG 1  or the second planetary gear mechanism PG 2  or in the differential gear mechanism  4 , it refers to the state where three or more rotation elements are drivingly coupled to each other with no other rotation elements interposed therebetween. 
     In the present embodiment, the first rotating electrical machine MG 1 , the second rotating electrical machine MG 2 , the first planetary gear mechanism PG 1 , and the second planetary gear mechanism PG 2  are arranged on a first axis X 1  that is a rotation axis of the first rotating electrical machine MG 1 , the second rotating electrical machine MG 2 , the first planetary gear mechanism PG 1 , and the second planetary gear mechanism PG 2 . That is, in the present embodiment, the first rotating electrical machine MG 1 , the second rotating electrical machine MG 2 , the first planetary gear mechanism PG 1 , and the second planetary gear mechanism PG 2  are coaxially arranged. The counter gear mechanism  3  is disposed on a second axis X 2  that is a rotation axis of the counter gear mechanism  3 . The differential gear mechanism  4  is disposed on a third axis X 3  that is a rotation axis of the differential gear mechanism  4 . The first axis X 1 , the second axis X 2 , and the third axis X 3  are imaginary axes that are different from each other, and are located parallel to each other. 
     In the following description, a direction parallel to the axes X 1  to X 3  is referred to as the “axial direction L” of the vehicle drive device  100 . The side in the axial direction L on which the second rotating electrical machine MG 2  is disposed with respect to the first planetary gear mechanism PG 1  is referred to as the “first side L 1  in the axial direction,” and the opposite side in the axial direction L is referred to as the “second side L 2  in the axial direction.” A direction perpendicular to each of the axes X 1  to X 3  is referred to as the “radial direction R” for each axis. When it is not necessary to identify the axis used for the radial direction, or when it is clear which axis is used for the radial direction, the direction is sometimes simply referred to as the “radial direction R.” 
     The input member  1  is provided so as to extend in the axial direction L. In the present embodiment, the input member  1  is disposed on the first side L 1  in the axial direction with respect to an internal combustion engine EG. The input member  1  is drivingly coupled to the internal combustion engine EG. It is preferable that the input member  1  be drivingly coupled to an output shaft (crankshaft, etc.) of the internal combustion engine EG via a damper device (not shown) that attenuates fluctuations in torque to be transmitted. The internal combustion engine EG is a motor (gasoline engine, diesel engine, etc.) that is driven by fuel combustion to output power. 
     The first rotating electrical machine MG 1  has a function as a motor (electric motor) that is supplied with electric power to generate power, and a function as a generator (electric generator) that is supplied with power to generate electric power. The first rotating electrical machine MG 1  is therefore electrically connected to an electric energy storage device (not shown). Various known electric energy storage devices such as a battery and a capacitor can be used as the electric energy storage device. In the present embodiment, the first rotating electrical machine MG 1  functions as a generator that generates electric power by the torque of the input member  1  (internal combustion engine EG) to charge the electric energy storage device or supply the electric power for driving the second rotating electrical machine MG 2 . However, the first rotating electrical machine MG 1  may function as a motor that performs power running to generate a driving force (synonymous with “torque”), for example, when a vehicle is traveling at high speeds or when the internal combustion engine EG is started. 
     The first rotating electrical machine MG 1  includes a first stator St 1  fixed to a non-rotation member (e.g., the case described above) and a first rotor Ro 1  supported so as to be rotatable relative to the first stator St 1 . In the present embodiment, the first rotor Ro 1  is disposed inside the first stator St 1  in the radial direction R. 
     The first planetary gear mechanism PG 1  corresponds to a “distribution differential gear mechanism” that distributes the driving force of the internal combustion engine EG transmitted to the input member  1  to the first rotating electrical machine MG 1  and the second transmission system T 2 . As described above, the vehicle drive device  100  according to the present embodiment is configured as what is called a power split hybrid vehicle drive device. In the present embodiment, the first planetary gear mechanism PG 1  is a single-pinion type planetary gear mechanism. Specifically, the first planetary gear mechanism PG 1  includes a first carrier C 1  supporting a first pinion gear P 1 , a first sun gear S 1  meshing with the first pinion gear P 1 , and a first ring gear R 1  disposed around the first sun gear S 1  in the radial direction R and meshing with the first pinion gear P 1 . 
     In the present embodiment, the first carrier C 1  is an input element of the first planetary gear mechanism PG 1  and is coupled to the input member  1  so as to rotate integrally with the input member  1 . That is, in the present embodiment, the first carrier C 1  corresponds to the “first rotation element” drivingly coupled to the input member  1 . The first pinion gear P 1  is rotatably supported by the first carrier C 1 . The first pinion gear P 1  rotates (rotates) about its axis and rotates (revolves) around the first sun gear S 1 . A plurality of the first pinion gears P 1  is provided along the revolution path of the first pinion gear P 1 . 
     In the present embodiment, the first sun gear S 1  is one of the rotation elements after distribution of the driving force in the first planetary gear mechanism PG 1  that is the distribution differential gear mechanism, and is coupled to the first rotor Ro 1  of the first rotating electrical machine MG 1  so as to rotate integrally with the first rotor Ro 1 . That is, in the present embodiment, the first sun gear S 1  corresponds to the “second rotation element” drivingly coupled to the first rotating electrical machine MG 1 . 
     In the present embodiment, the first ring gear R 1  is the other rotation element after distribution of the driving force in the first planetary gear mechanism PG 1  that is the distribution differential gear mechanism. In the present embodiment, the first ring gear R 1  corresponds to the “third rotation element” of the distribution differential gear mechanism (first planetary gear mechanism PG 1 ). In the present embodiment, the first ring gear R 1  is coupled to a cylindrical gear forming member  21  so as to rotate integrally with the gear forming member  21 . In this example, the first ring gear R 1  is formed on the inner peripheral surface of the gear forming member  21 . 
     In the present embodiment, the counter drive gear  2  is coupled to the first ring gear R 1  of the first planetary gear mechanism PG 1  via the gear forming member  21  so as to rotate integrally with the first ring gear R 1 . That is, the counter drive gear  2  corresponds to the “first gear” coupled to the third rotation element (first ring gear R 1 ) so as to rotate integrally with the third rotation element. In this example, the counter drive gear  2  is formed on the outer peripheral surface of the gear forming member  21 . 
     The second rotating electrical machine MG 2  has a function as a motor (electric motor) that is supplied with electric power to generate power, and a function as a generator (electric generator) that is supplied with power to generate electric power. Like the first rotating electrical machine MG 1 , the second rotating electrical machine MG 2  is therefore also electrically connected to the electric energy storage device. In the present embodiment, the second rotating electrical machine MG 2  mainly functions as a motor that generates a driving force for causing the vehicle to travel. However, the second rotating electrical machine MG 2  may function as a generator that regenerates the inertial force of the vehicle as electric energy, for example, during deceleration of the vehicle. 
     The second rotating electrical machine MG 2  includes a second stator St 2  fixed to the non-rotation member (e.g., the case described above) and a second rotor Ro 2  supported so as to be rotatable relative to the second stator St 2 . In the present embodiment, the second rotor Ro 2  is disposed inside the second stator St 2  in the radial direction R. A rotor shaft RS extending in the axial direction L is coupled to the second rotor Ro 2  so as to rotate integrally with the second rotor Ro 2 . In the present embodiment, the rotor shaft RS is disposed inside the second rotor Ro 2  in the radial direction R. 
     The second planetary gear mechanism PG 2  corresponds to the “speed reducer” that reduces the speed of rotation of the second rotating electrical machine MG 2  to transmit the resultant rotation to the first gear (counter drive gear  2 ). In the present embodiment, the second planetary gear mechanism PG 2  is a single-pinion type planetary gear mechanism. Specifically, the second planetary gear mechanism PG 2  includes a second carrier C 2  supporting a second pinion gear P 2 , a second sun gear S 2  meshing with the second pinion gear P 2 , and a second ring gear R 2  disposed around the second sun gear S 2  in the radial direction R and meshing with the second pinion gear P 2 . 
     In the present embodiment, the second sun gear S 2  is an input element of the second planetary gear mechanism PG 2  and is coupled to the rotor shaft RS of the second rotating electrical machine MG 2  so as to rotate integrally with the rotor shaft RS. The second ring gear R 2  is supported so as not to be rotatable relative to the non-rotation member (e.g., the case described above) in the circumferential direction. The second carrier C 2  is an output element of the second planetary gear mechanism PG 2  and is coupled to the gear forming member  21  so as to rotate integrally with the gear forming member  21 . That is, in the present embodiment, the second carrier C 2 , the first ring gear R 1 , and the counter drive gear  2  rotate integrally. The second pinion gear P 2  is rotatably supported by the second carrier C 2 . The second pinion gear P 2  rotates (rotates) about its axis and rotates (revolves) around the second sun gear S 2 . A plurality of the second pinion gears P 2  is provided along the revolution path of the second pinion gear P 2 . 
     The counter gear mechanism  3  is disposed in a power transmission path between the counter drive gear  2  and the differential gear mechanism  4 . The counter gear mechanism  3  includes a first counter gear  31 , a second counter gear  32 , and a counter shaft  33 . 
     The first counter gear  31  is an input element of the counter gear mechanism  3 . The first counter gear  31  meshes with the counter drive gear  2 . That is, the first counter gear  31  corresponds to the “second gear” meshing with the first gear (counter drive gear  2 ). 
     The second counter gear  32  is an output element of the counter gear mechanism  3 . The second counter gear  32  is integrally coupled to the first counter gear  31  via the counter shaft  33  extending in the axial direction L. That is, the second counter gear  32  corresponds to the “third gear” that rotates integrally with the second gear (first counter gear  31 ). In the present embodiment, the second counter gear  32  is disposed on the second side L 2  in the axial direction with respect to the first counter gear  31 . In the present embodiment, the second counter gear  32  has a smaller diameter than the first counter gear  31 . 
     The differential gear mechanism  4  includes a differential input gear  41 . The differential input gear  41  is an input element of the differential gear mechanism  4 . The differential input gear  41  meshes with the second counter gear  32  of the counter gear mechanism  3 . That is, the differential input gear  41  corresponds to the “fourth gear” meshing with the third gear (second counter gear  32 ). 
     In the present embodiment, the differential gear mechanism  4  is a bevel gear type differential gear mechanism. Specifically, the differential gear mechanism  4  includes a hollow differential case, a pinion shaft supported so as to rotate integrally with the differential case, a pair of pinion gears supported so as to be rotatable relative to the pinion shaft, and a pair of side gears meshing with the pair of pinion gears and functioning as distribution output elements. The pinion shaft, the pair of pinion gears, and the pair of side gears are housed in the differential case. In the present embodiment, the differential input gear  41  is coupled to the differential case so as to protrude outward in the radial direction R from the differential case. 
     The output member  5  is drivingly coupled to wheels W. The output member  5  includes a pair of output units  51 . Each of the pair of output units  51  is drivingly coupled to the wheel W via a drive shaft DS. In the present embodiment, each output unit  51  is coupled to a corresponding one of the pair of side gears of the differential gear mechanism  4  so as to rotate integrally with the corresponding side gear. For example, the output unit  51  can be a tubular member that is formed integrally with the corresponding side gear of the differential gear mechanism  4  and that is coupled to the drive shaft DS disposed inside the tubular member in the radial direction R such that the tubular member rotates integrally with the drive shaft DS. The differential gear mechanism  4  therefore corresponds to the “output differential gear mechanism” that distributes rotation of the fourth gear (differential input gear  41 ) to the pair of output units  51  that is the output member  5 . 
     As shown in  FIGS. 1 and 2 , the vehicle drive device  100  further includes a first hydraulic pump  61  and a second hydraulic pump  62 . 
     The first hydraulic pump  61  is a hydraulic pump that is driven by the driving force transmitted through the second transmission system T 2 . In the present embodiment, the first hydraulic pump  61  includes a pump drive gear  611  for driving the first hydraulic pump  61 . The pump drive gear  611  meshes with the counter drive gear  2  at a different position from the first counter gear  31  in the circumferential direction of the counter drive gear  2 . As described above, in the present embodiment, the pump drive gear  611  meshing with the counter drive gear  2  of the second transmission system T 2  rotates with rotation of the counter drive gear  2 . The first hydraulic pump  61  is thus driven by the rotation of the pump drive gear  611 . 
     The second hydraulic pump  62  is a hydraulic pump that is driven by a dedicated driving force source, the dedicated driving force source being independent of the first transmission system T 1  and the second transmission system T 2 . As shown in  FIG. 2 , in the present embodiment, the second hydraulic pump  62  is an electrically operated hydraulic pump that is driven by an electric motor  62   a . For example, the electric motor  62   a  can be an alternating current (AC) rotating electrical machine that is driven by a plurality of phases of AC power. In this case, although not shown in the figures, the electric motor  62   a  is connected to a direct current (DC) power supply via an inverter that converts electric power between DC power and AC power. Driving of the electric motor  62   a  is controlled via the inverter. 
     As shown in  FIG. 2 , the vehicle drive device  100  has a first oil passage PS 1  that supplies oil discharged from the first hydraulic pump  61  to the second transmission system T 2 , a second oil passage PS 2  that supplies oil discharged from the second hydraulic pump  62  to the first transmission system T 1 , a third oil passage PS 3  that supplies the oil discharged from the second hydraulic pump  62  to the first rotating electrical machine MG 1 , and a fourth oil passage PS 4  that supplies the oil discharged from the second hydraulic pump  62  to the second rotating electrical machine MG 2 . In the present embodiment, the vehicle drive device  100  further has a fifth oil passage PS 5  that supplies the oil discharged from the first hydraulic pump  61  to the first rotating electrical machine MG 1 , and a sixth oil passage PS 6  that supplies the oil discharged from the first hydraulic pump  61  to the second rotating electrical machine MG 2 . 
     In the present embodiment, the first oil passage PS 1  includes a second supply passage  71   b  that supplies oil to the second planetary gear mechanism PG 2 , a first lubrication oil passage  72   a  that supplies oil to the counter gear mechanism  3 , and a second lubrication oil passage  72   b  that supplies oil to the differential gear mechanism  4 . 
     In the present embodiment, the second supply passage  71   b  is disposed inward of the first rotating electrical machine MG 1 , the second rotating electrical machine MG 2 , the first planetary gear mechanism PG 1 , and the second planetary gear mechanism PG 2  in the radial direction R. The second supply passage  71   b  is configured to supply oil to the second planetary gear mechanism PG 2  from the inner side in the radial direction R. The oil that has reached the second planetary gear mechanism PG 2  through the second supply passage  71   b  is supplied to the meshing portions between the second pinion gears P 2  and the second sun gear S 2  and between the second pinion gears P 2  and the second ring gear R 2 , bearings that rotatably support these gears and the second carrier C 2 , etc. Although not shown in the figures, in the present embodiment, a plurality of the second supply passages  71   b  is arranged in the circumferential direction about the first axis X 1 . 
     In the present embodiment, the first lubrication oil passage  72   a  is disposed on the second axis X 2 . The oil that has reached the counter gear mechanism  3  through the first lubrication oil passage  72   a  is supplied to the meshing portion between the first counter gear  31  and the counter drive gear  2 , the meshing portion between the second counter gear  32  and the differential input gear  41 , bearings that rotatably support the counter shaft  33 , etc. 
     In the present embodiment, the second lubrication oil passage  72   b  is disposed on the third axis X 3 . The second lubrication oil passage  72   b  communicates with the first lubrication oil passage  72   a . That is, in the present embodiment, the second lubrication oil passage  72   b  branches from the first lubrication oil passage  72   a  and extends along the third axis X 3  toward the differential gear mechanism  4 . The oil that has reached the differential gear mechanism  4  through the second lubrication oil passage  72   b  is supplied to bearings that rotatably support the differential case, the meshing portions between the pinion gears and the side gears, etc. 
     In the present embodiment, the second oil passage PS 2  includes a first supply passage  71   a  that supplies oil to the first planetary gear mechanism PG 1 . 
     In the present embodiment, the first supply passage  71   a  is disposed inward of the first rotating electrical machine MG 1 , the second rotating electrical machine MG 2 , the first planetary gear mechanism PG 1 , and the second planetary gear mechanism PG 2  in the radial direction R. The first supply passage  71   a  is configured to supply oil to the first planetary gear mechanism PG 1  from the inner side in the radial direction R. The oil that has reached the first planetary gear mechanism PG 1  through the first supply passage  71   a  is supplied to the meshing portions between the first pinion gears P 1  and the first sun gear S 1  and between the first pinion gears P 1  and the first ring gear R 1 , bearings that rotatably support these gears and the first carrier C 1 , etc. Although not shown in the figures, in the present embodiment, a plurality of the first supply passages  71   a  is arranged in the circumferential direction about the first axis X 1 . 
     In the present embodiment, the third oil passage PS 3  includes a first outer oil passage  73   a  that supplies oil to the first rotating electrical machine MG 1  from the outer side in the radial direction R. 
     In the present embodiment, the first outer oil passage  73   a  is disposed outward of the first rotating electrical machine MG 1 , the second rotating electrical machine MG 2 , the first planetary gear mechanism PG 1 , and the second planetary gear mechanism PG 2  in the radial direction R. The oil that has reached the first rotating electrical machine MG 1  through the first outer oil passage  73   a  is supplied to coil end portions of a stator coil of the first stator St 1 , etc. 
     In the present embodiment, the fourth oil passage PS 4  includes a second outer oil passage  73   b  that supplies oil to the second rotating electrical machine MG 2  from the outer side in the radial direction R. 
     In the present embodiment, the second outer oil passage  73   b  is disposed outward of the first rotating electrical machine MG 1 , the second rotating electrical machine MG 2 , the first planetary gear mechanism PG 1 , and the second planetary gear mechanism PG 2  in the radial direction R. The oil that has reached the second rotating electrical machine MG 2  through the second outer oil passage  73   b  is supplied to coil end portions of a stator coil of the second stator St 2 , etc. 
     The fifth oil passage PS 5  includes a first inner oil passage  74   a  that supplies oil to the first rotating electrical machine MG 1  from the inner side in the radial direction R. 
     In the present embodiment, the first inner oil passage  74   a  is disposed inward of the first rotating electrical machine MG 1 , the second rotating electrical machine MG 2 , the first planetary gear mechanism PG 1 , and the second planetary gear mechanism PG 2  in the radial direction R. The oil that has reached the first rotating electrical machine MG 1  through the first inner oil passage  74   a  is supplied to the first rotor Ro 1 , bearings that rotatably support the first rotor Ro 1 , etc. Although not shown in the figures, in the present embodiment, a plurality of the first inner oil passages  74   a  is arranged in the circumferential direction about the first axis X 1 . 
     The sixth oil passage PS 6  includes a second inner oil passage  74   b  that supplies oil to the second rotating electrical machine MG 2  from the inner side in the radial direction R. 
     In the present embodiment, the second inner oil passage  74   b  is disposed inward of the first rotating electrical machine MG 1 , the second rotating electrical machine MG 2 , the first planetary gear mechanism PG 1 , and the second planetary gear mechanism PG 2  in the radial direction R. The oil that has reached the second rotating electrical machine MG 2  through the second inner oil passage  74   b  is supplied to the second rotor Ro 2 , bearings that rotatably support the rotor shaft RS, etc. Although not shown in the figures, in the present embodiment, a plurality of the second inner oil passages  74   b  is arranged in the circumferential direction about the first axis X 1 . 
     In the present embodiment, an axis oil passage  75  is disposed inward of the first rotating electrical machine MG 1 , the second rotating electrical machine MG 2 , the first planetary gear mechanism PG 1 , and the second planetary gear mechanism PG 2  in the radial direction R. The axis oil passage  75  is formed so as to communicate with the first inner oil passages  74   a , the first supply passages  71   a , and the second supply passages  71   b . In the present embodiment, the axis oil passage  75  is also formed so as to communicate with the second inner oil passages  74   b . The axis oil passage  75  therefore serves as a part of the first oil passage PS 1 , a part of the second oil passage PS 2 , a part of the fifth oil passage PS 5 , and a part of the sixth oil passage PS 6 . In the present embodiment, the axis oil passage  75  is formed so as to extend in the axial direction L on the first axis X 1 . The first inner oil passages  74   a , the second inner oil passages  74   b , the first supply passages  71   a , and the second supply passages  71   b  are formed so as to extend outward in the radial direction R from the axis oil passage  75 . 
     In the present embodiment, a first discharge oil passage  76   a  and a second discharge oil passage  76   b  are disposed so as to merge with the axis oil passage  75 . In the present embodiment, the first discharge oil passage  76   a  and the second discharge oil passage  76   b  are disposed so as to communicate with an end on the first side L 1  in the axial direction of the axis oil passage  75 . 
     The first discharge oil passage  76   a  is an oil passage which is connected to the first hydraulic pump  61  and through which the oil discharged from the first hydraulic pump  61  flows. In the present embodiment, the first discharge oil passage  76   a  communicates with the second supply passages  71   b , the first inner oil passages  74   a , and the second inner oil passages  74   b  through the axis oil passage  75 . The first discharge oil passage  76   a  therefore serves as a part of the first oil passage PS 1 , a part of the fifth oil passage PS 5 , and a part of the sixth oil passage PS 6 . In the present embodiment, the first lubrication oil passage  72   a  is formed so as to branch from the first discharge oil passage  76   a.    
     The second discharge oil passage  76   b  is an oil passage which is connected to the second hydraulic pump  62  and through which the oil discharged from the second hydraulic pump  62  flows. In the present embodiment, the second discharge oil passage  76   b  communicates with the first supply passages  71   a  through the axis oil passage  75 . The second discharge oil passage  76   b  therefore serves as a part of the second oil passage PS 2 . 
     In the present embodiment, the first outer oil passage  73   a  and the second outer oil passage  73   b  are also connected to the second hydraulic pump  62 . The oil discharged from the second hydraulic pump  62  is cooled by an oil cooler  63  before being supplied to the first outer oil passage  73   a  and the second outer oil passage  73   b . The oil cooler  63  includes, for example, a pipe through which oil flows, and is configured to cool the oil by heat exchange between a cooling medium (e.g., coolant, air, etc.) flowing outside the pipe and the oil inside the pipe. In this example, the first outer oil passage  73   a  and the second outer oil passage  73   b  are formed integrally from the connection portion with the second hydraulic pump  62  to the branch portion on the downstream side. The oil cooler  63  is disposed in this integral portion. 
     In the present embodiment, the vehicle drive device  100  further includes a valve mechanism  8 . The valve mechanism  8  is configured to selectively supply either the oil discharged from the first hydraulic pump  61  or the oil discharged from the second hydraulic pump  62  to the first inner oil passages  74   a  and the first supply passages  71   a . In the present embodiment, the valve mechanism  8  is configured to selectively supply either the oil discharged from the first hydraulic pump  61  or the oil discharged from the second hydraulic pump  62  to the axis oil passage  75 . That is, in the present embodiment, the valve mechanism  8  selectively supplies either the oil discharged from the first hydraulic pump  61  or the oil discharged from the second hydraulic pump  62  to the first inner oil passages  74   a , the second inner oil passages  74   b , the first supply passages  71   a , and the second supply passages  71   b.    
     In the present embodiment, the valve mechanism  8  includes a first valve  81  and a second valve  82 . In the present embodiment, the first valve  81  is disposed in the first discharge oil passage  76   a  at a position downstream of the connection portion of the first discharge oil passage  76   a  with the first lubrication oil passage  72   a . The second valve  82  is disposed in the second discharge oil passage  76   b . In the present embodiment, the first valve  81  is a check valve that allows the flow of oil from the first hydraulic pump  61  side to the axis oil passage  75  side but restricts the flow of oil in the opposite direction. The second valve  82  is a check valve that allows the flow of oil from the second hydraulic pump  62  side to the axis oil passage  75  side but restricts the flow of oil in the opposite direction. Therefore, when the oil pressure in the first discharge oil passage  76   a  is higher than that in the second discharge oil passage  76   b , only the oil discharged from the first hydraulic pump  61  is supplied to the axis oil passage  75 . In contrast, when the oil pressure in the first discharge oil passage  76   a  is lower than that in the second discharge oil passage  76   b , only the oil discharged from the second hydraulic pump  62  is supplied to the axis oil passage  75 . 
     In the vehicle drive device  100  configured as described above, even in the case where the wheels W are stopped or in the case where the rotational speed of the wheels W is low and the discharge pressure of the first hydraulic pump  61  is therefore low, oil can be supplied to the first rotating electrical machine MG 1  and the second rotating electrical machine MG 2  by the second hydraulic pump  62 . For example, in the case where the driving force of the internal combustion engine EG is used to generate electric power by the first rotating electrical machine MG 1  while the wheels W are stopped, oil can be supplied to the first transmission system T 1  (first planetary gear mechanism PG 1 ) through the second oil passage PS 2  (second discharge oil passage  76   b , axis oil passage  75 , and first supply passages  71   a ) and oil can be supplied to the first rotating electrical machine MG 1  through the third oil passage PS 3  (first outer oil passage  73   a ), both by the second hydraulic pump  62 . Moreover, in the present embodiment, oil can also be supplied to the first rotating electrical machine MG 1  through the first inner oil passages  74   a  by the second hydraulic pump  62 . For example, in the case where the vehicle equipped with the vehicle drive device  100  is started after stalling by the driving force of the second rotating electrical machine MG 2 , oil can be supplied to the second rotating electrical machine MG 2  through the fourth oil passage PS 4  (second outer oil passage  73   b ) by the second hydraulic pump  62 . Furthermore, in the present embodiment, oil can also be supplied to the second rotating electrical machine MG 2  through the second inner oil passages  74   b  by the second hydraulic pump  62 . 
     In the case where the vehicle equipped with the vehicle drive device  100  is traveling by the driving force of the second rotating electrical machine MG 2 , the first hydraulic pump  61  is driven by the driving force transmitted through the second transmission system T 2 . Oil is thus supplied from the first hydraulic pump  61  to the second transmission system T 2  through the first oil passage PS 1  (first discharge oil passage  76   a , axis oil passage  75 , second supply passages  71   b , first lubrication oil passage  72   a , and second lubrication oil passage  72   b ). It is therefore not necessary to supply oil to the second transmission system T 2  by the second hydraulic pump  62 , and the second hydraulic pump  62  need only be able to supply oil to the second rotating electrical machine MG 2  through the fourth oil passage PS 4  (second outer oil passage  73   b ). Accordingly, the second hydraulic pump  62  can be reduced in size, and reduction in size of the vehicle drive device  100  can be achieved. 
     In the vehicle drive device  100 , the first hydraulic pump  61  is driven by the driving force transmitted through the second transmission system T 2  that drivingly couples the second rotating electrical machine MG 2  and the output member  5 . Therefore, the rotational speed of the first hydraulic pump  61  depends on the rotational speed of the wheels W. On the other hand, in a configuration in which the first hydraulic pump  61  is driven by the driving force of the internal combustion engine EG transmitted to the input member  1 , the rotational speed of the first hydraulic pump  61  depends on the rotational speed of the internal combustion engine EG. Regarding the rotational speed of the internal combustion engine EG, an appropriate rotational speed range has been set for each type of internal combustion engine EG. Accordingly, in the configuration in which the first hydraulic pump  61  is driven by the driving force of the internal combustion engine EG transmitted to the input member  1 , it is necessary to change the specifications of the first hydraulic pump  61  for each type of internal combustion engine EG so that the first hydraulic pump  61  is driven in the rotational speed range corresponding to the type of internal combustion engine EG. As described above, however, in the vehicle drive device  100 , since the rotational speed of the first hydraulic pump  61  depends on the rotational speed of the wheels W, there is no need to change the specifications of the first hydraulic pump  61  for each type of internal combustion engine EG. 
     2. Second Embodiment 
     Hereinafter, the vehicle drive device  100  according to a second embodiment will be described with reference to the drawings. The vehicle drive device  100  according to the present embodiment is different from the vehicle drive device  100  according to the first embodiment in that the vehicle drive device  100  according to the first embodiment is a power split hybrid vehicle drive device, whereas the vehicle drive device  100  according to the present embodiment is configured as what is called a series-parallel hybrid vehicle drive device. Accordingly, in the present embodiment, the first planetary gear mechanism PG 1  is a speed increaser. The vehicle drive device  100  includes an engagement device CL that connects and disconnects the first transmission system T 1  and the second transmission system T 2  to and from each other. The present embodiment will be described below, focusing on the differences from the first embodiment. The present embodiment is similar to the first embodiment in regard to the points that are not particularly described. 
     As shown in  FIG. 3 , in the present embodiment, the vehicle drive device  100  includes the engagement device CL that connects and disconnects the first transmission system T 1  and the second transmission system T 2  to and from each other. In the present embodiment, the engagement device CL is disposed on the first axis X 1 . In the present embodiment, the engagement device CL is a meshing engagement device (dog clutch) and is configured to switch between an engaged state and a disengaged state by an actuator such as a solenoid. 
     Specifically, the engagement device CL has a first claw portion CLa configured to move in the axial direction L by the actuator and a second claw portion CLb to which the first claw portion CLa is engaged. The first claw portion CLa rotates integrally with the input member  1  and is supported by the input member  1  so as to be movable in the axial direction L. The second claw portion CLb is provided so as to rotate integrally with the counter drive gear  2 . In the present embodiment, the first claw portion CLa is disposed at an end on the first side L 1  in the axial direction of the input member  1 . The second claw portion CLb is formed so as to protrude from the counter drive gear  2  to the second side L 2  in the axial direction. 
     The engagement device CL is engaged when the first claw portion CLa is engaged with the second claw portion CLb, and is disengaged when the first claw portion CLa is separated from the second claw portion CLb. When the engagement device CL is in the engaged state, power is transmitted between the first transmission system T 1  and the second transmission system T 2 . That is, when the engagement device CL is in the engaged state, the vehicle is in a parallel hybrid mode in which, in addition to the driving force of the second rotating electrical machine MG 2 , the driving force of the internal combustion engine EG transmitted to the input member  1  and the driving force of the first rotating electrical machine MG 1  are transmitted to the output member  5 . In the present embodiment, since the engagement device CL is a meshing engagement device, the input member  1  and the counter drive gear  2  rotate integrally when the engagement device CL is in the engaged state. In contrast, when the engagement device CL is in the disengaged state, the power transmission between the first transmission system T 1  and the second transmission system T 2  is cut off. That is, when the engagement device CL is in the disengaged state, the vehicle is in a series hybrid mode in which the driving force of the second rotating electrical machine MG 2  is transmitted to the output member  5  and the driving force of the internal combustion engine EG transmitted to the input member  1  is transmitted to the first rotating electrical machine MG 1 . In this mode, the second rotating electrical machine MG 2  is driven by the electric power obtained by power generation of the first rotating electrical machine MG 1 . 
     In the present embodiment, the first planetary gear mechanism PG 1  is a speed increaser. In the present embodiment, the first carrier C 1  is an input element of the first planetary gear mechanism PG 1  and is coupled to the input member  1  so as to rotate integrally with the input member  1 . The first ring gear R 1  is supported so as not to be rotatable relative to the non-rotation member (e.g., the case described above) in the circumferential direction. The first sun gear S 1  is an output element of the first planetary gear mechanism PG 1  and is coupled to the first rotor Ro 1  of the first rotating electrical machine MG 1  so as to rotate integrally with the first rotor Ro 1 . Rotation of the input member  1  is therefore increased in speed and transmitted to the first rotor Ro 1  of the first rotating electrical machine MG 1 . 
     In the present embodiment as well, the second planetary gear mechanism PG 2  is the “speed reducer” that reduces the speed of rotation of the second rotating electrical machine MG 2  to transmit the resultant rotation to the first gear (counter drive gear  2 ). 
     A hydraulic circuit similar to that of the vehicle drive device  100  according to the first embodiment is formed in the vehicle drive device  100  according to the second embodiment. 
     3. Third Embodiment 
     Hereinafter, a vehicle drive device  100  according to a third embodiment will be described with reference to the drawings. Like the vehicle drive device  100  according to the first embodiment, the vehicle drive device  100  according to the present embodiment is configured as a power split hybrid vehicle drive device. However, the vehicle drive device  100  according to the present embodiment is different from the vehicle drive device  100  according to the first embodiment in that the vehicle drive device  100  according to the present embodiment does not include the second planetary gear mechanism PG 2  that is a speed reducer. The vehicle drive device  100  according to the present embodiment is also different from the vehicle drive device  100  according to the first embodiment in that the first rotating electrical machine MG 1 , the second rotating electrical machine MG 2 , and the first planetary gear mechanism PG 1  are not coaxially arranged. Moreover, the element with which the pump drive gear  611  of the first hydraulic pump  61  meshes is different between the present embodiment and the first embodiment. The present embodiment will be described below, focusing on the differences from the first embodiment. The present embodiment is similar to the first embodiment in regard to the points that are not particularly described. 
     As shown in  FIG. 4 , in the present embodiment, the first planetary gear mechanism PG 1  is disposed on the first axis X 1  that is a rotation axis of the first planetary gear mechanism PG 1 . The counter gear mechanism  3  is disposed on a second axis X 2  that is a rotation axis of the counter gear mechanism  3 . The differential gear mechanism  4  is disposed on a third axis X 3  that is a rotation axis of the differential gear mechanism  4 . The first rotating electrical machine MG 1  is disposed on a fourth axis X 4  that is a rotation axis of the first rotor Ro 1 . The second rotating electrical machine MG 2  is disposed on a fifth axis X 5  that is a rotation axis of the second rotor Ro 2 . That is, in the present embodiment, the first rotating electrical machine MG 1 , the second rotating electrical machine MG 2 , the first planetary gear mechanism PG 1 , the counter gear mechanism  3 , and the differential gear mechanism  4  are disposed on the different axes from each other. These axes X 1  to X 5  are imaginary axes that are different from each other, and are located parallel to each other. 
     In the present embodiment, the first transmission system T 1  includes a distribution output gear  9  and a first rotor gear RG 1  in addition to the first planetary gear mechanism PG 1 . 
     The distribution output gear  9  is coupled to the first sun gear S 1  of the first planetary gear mechanism PG 1  so as to rotate integrally with the first sun gear S 1 . That is, the distribution output gear  9  corresponds to the “sixth gear” that rotates integrally with the second rotation element of the first planetary gear mechanism PG 1 . In the present embodiment, the distribution output gear  9  is disposed on the first axis X 1 . 
     The first rotor gear RG 1  is coupled to the first rotor Ro 1  of the first rotating electrical machine MG 1  so as to rotate integrally with the first rotor Ro 1 . The first rotor gear RG 1  meshes with the distribution output gear  9 . That is, the first rotor gear RG 1  corresponds to the “seventh gear” that rotates integrally with the first rotor Ro 1  of the first rotating electrical machine MG 1  and that meshes with the sixth gear (distribution output gear  9 ). In the present embodiment, the first rotor gear RG 1  is disposed on the fourth axis X 4 . In the present embodiment, the first rotor gear RG 1  is coupled to the first rotor Ro 1  via a first rotor shaft RS 1  so as to rotate integrally with the first rotor Ro 1 . The first rotor shaft RS 1  is provided so as to extend in the axial direction L. In the present embodiment, the first rotor shaft RS 1  is disposed inside the first rotor Ro 1  in the radial direction R. 
     In the present embodiment, the second transmission system T 2  includes a second rotor gear RG 2  in addition to the counter drive gear  2 , the counter gear mechanism  3 , and the differential gear mechanism  4 . In the present embodiment, the second transmission system T 2  does not include the second planetary gear mechanism PG 2 . 
     The second rotor gear RG 2  is coupled to the second rotor Ro 2  of the second rotating electrical machine MG 2  so as to rotate integrally with the second rotor Ro 2 . The second rotor gear RG 2  meshes with the counter drive gear  2 . That is, the second rotor gear RG 2  corresponds to the “fifth gear” that rotates integrally with the second rotor Ro 2  of the second rotating electrical machine MG 2  and that meshes with the first gear (counter drive gear  2 ). In the present embodiment, the second rotor gear RG 2  meshes with the counter drive gear  2  at a different position from the first counter gear  31  in the circumferential direction of the counter drive gear  2 . Moreover, in the present embodiment, the second rotor gear RG 2  is disposed on the fifth axis X 5 . In the present embodiment, the second rotor gear RG 2  is coupled to the first rotor Ro 1  via a second rotor shaft RS 2  so as to rotate integrally with the first rotor Ro 1 . The first rotor shaft RS 1  is provided so as to extend in the axial direction L. In the present embodiment, the first rotor shaft RS 1  is disposed inside the first rotor Ro 1  in the radial direction R. 
     In the present embodiment, the pump drive gear  611  of the first hydraulic pump  61  meshes with the differential input gear  41  at a different position from the second counter gear  32  in the circumferential direction of the differential input gear  41 . As described above, in the present embodiment, the pump drive gear  611  meshing with the differential input gear  41  included in the differential gear mechanism  4  of the second transmission system T 2  rotates with rotation of the differential input gear  41 . The first hydraulic pump  61  is thus driven by the rotation of the pump drive gear  611 . 
     In the present embodiment, the second counter gear  32  of the counter gear mechanism  3  is disposed on the first side L 1  in the axial direction with respect to the first counter gear  31 . 
     A hydraulic circuit of the vehicle drive device  100  according to the present embodiment will be described below with reference to  FIG. 4 . As described above, in the present embodiment, the first rotating electrical machine MG 1 , the second rotating electrical machine MG 2 , and the first planetary gear mechanism PG 1  are not coaxially arranged. Therefore, in the present embodiment, a first axis oil passage  75 A, a second axis oil passage  75 B, and a third axis oil passage  75 C are provided for the first rotating electrical machine MG 1 , the second rotating electrical machine MG 2 , and the first planetary gear mechanism PG 1 , respectively, instead of the axis oil passage  75  disposed inward of the first rotating electrical machine MG 1 , the second rotating electrical machine MG 2 , and the first planetary gear mechanism PG 1  in the radial direction R. 
     As shown in  FIG. 4 , the first axis oil passage  75 A is disposed inward of the first rotating electrical machine MG 1  in the radial direction R. The first axis oil passage  75 A is formed so as to communicate with the first inner oil passages  74   a . In the present embodiment, the first axis oil passage  75 A is formed so as to extend in the axial direction L on the fourth axis X 4 . 
     The second axis oil passage  75 B is disposed inward of the second rotating electrical machine MG 2  in the radial direction R. The second axis oil passage  75 B is formed so as to communicate with the second inner oil passages  74   b . In the present embodiment, the second axis oil passage  75 B is formed so as to extend in the axial direction L on the fifth axis X 5 . 
     The third axis oil passage  75 C is disposed inward of the first planetary gear mechanism PG 1  in the radial direction R. The third axis oil passage  75 C is formed so as to communicate with the first supply passages  71   a . In the present embodiment, the third axis oil passage  75 C is formed so as to extend in the axial direction L on the first axis X 1 . 
     In the present embodiment, the first discharge oil passage  76   a  is formed so as to communicate with the first axis oil passage  75 A and the second axis oil passage  75 B. In the illustrated example, a downstream end of the first discharge oil passage  76   a  and an end on the first side L 1  in the axial direction of the second axis oil passage  75 B are connected together. An intermediate portion of the first discharge oil passage  76   a  and an end on the first side L 1  in the axial direction of the first axis oil passage  75 A are connected together. 
     In the present embodiment, the second discharge oil passage  76   b  is formed so as to communicate with the first outer oil passage  73   a  and the second outer oil passage  73   b . In the present embodiment, the oil cooler  63  is disposed in the second discharge oil passage  76   b.    
     In the present embodiment, the first axis oil passage  75 A and the third axis oil passage  75 C are connected by a first connecting oil passage  77   a . The first axis oil passage  75 A and the second discharge oil passage  76   b  are connected by a second connecting oil passage  77   b.    
     In the present embodiment, the valve mechanism  8  is configured to selectively supply either the oil discharged from the first hydraulic pump  61  or the oil discharged from the second hydraulic pump  62  to the first axis oil passage  75 A and the third axis oil passage  75 C. 
     In the present embodiment, the first valve  81  is disposed in the first axis oil passage  75 A at a position upstream of the connection portion of the first axis oil passage  75 A with the second connecting oil passage  77   b . The second valve  82  is disposed in the second connecting oil passage  77   b . Therefore, when the oil pressure in the first discharge oil passage  76   a  is higher than that in the second discharge oil passage  76   b , only the oil discharged from the first hydraulic pump  61  is supplied to the first axis oil passage  75 A. In contrast, when the oil pressure in the first discharge oil passage  76   a  is lower than that in the second discharge oil passage  76   b , only the oil discharged from the second hydraulic pump  62  is supplied to the first axis oil passage  75 A. 
     In the present embodiment, the first axis oil passage  75 A is formed so that the oil discharged from the first hydraulic pump  61  is supplied to the first axis oil passage  75 A through the first discharge oil passage  76   a  and that the oil discharged from the second hydraulic pump  62  is supplied to the first axis oil passage  75 A through the second discharge oil passage  76   b  and the second connecting oil passage  77   b . The first axis oil passage  75 A is formed so as to communicate with the first inner oil passages  74   a  and to communicate with the first supply passages  71   a  through the first connecting oil passage  77   a  and the third axis oil passage  75 C. The first axis oil passage  75 A therefore serves as a part of the fifth oil passage PS 5  and a part of the second oil passage PS 2 . 
     In the present embodiment, the second axis oil passage  75 B is formed so as to communicate with the second inner oil passages  74   b . The second axis oil passage  75 B therefore serves as a part of the sixth oil passage PS 6 . The third axis oil passage  75 C is formed so as to communicate with the first supply passages  71   a . The third axis oil passage  75 C therefore serves as a part of the second oil passage PS 2 . 
     In the present embodiment, the first discharge oil passage  76   a  is formed so as to communicate with the first inner oil passages  74   a  through the first axis oil passage  75 A and to communicate with the second inner oil passages  74   b  through the second axis oil passage  75 B. The first discharge oil passage  76   a  therefore serves as a part of the fifth oil passage PS 5  and a part of the sixth oil passage PS 6 . The second discharge oil passage  76   b  is formed so as to communicate with the first outer oil passage  73   a  and the second outer oil passage  73   b . The second discharge oil passage  76   b  therefore serves as a part of the third oil passage PS 3  and a part of the fourth oil passage PS 4 . 
     In the present embodiment, the first connecting oil passage  77   a  is formed so as to communicate with the first supply passages  71   a  through the third axis oil passage  75 C. The first connecting oil passage  77   a  therefore serves as a part of the second oil passage PS 2 . The second connecting oil passage  77   b  is formed so as to supply the oil discharged from the second hydraulic pump  62  to the first axis oil passage  75 A and to communicate with the first supply passages  71   a  through the first axis oil passage  75 A, the first connecting oil passage  77   a , and the third axis oil passage  75 C. The second connecting oil passage  77   b  therefore serves as a part of the second oil passage PS 2 . 
     4. Other Embodiments 
     (1) In the above embodiments, the configuration in which the vehicle drive device has the fifth oil passage PS 5  and the sixth oil passage PS 6  is described by way of example. However, the present disclosure is not limited to such a configuration. The vehicle drive device may have either the fifth oil passage PS 5  or the sixth oil passage PS 6  or may have both of them. 
     (2) In the above embodiments, the configuration in which the fifth oil passage PS 5  includes the first inner oil passages  74   a  that supply oil to the first rotating electrical machine MG 1  from the inner side in the radial direction R and the sixth oil passage PS 6  includes the second inner oil passages  74   b  that supply oil to the second rotating electrical machine MG 2  from the inner side in the radial direction R is described by way of example. However, the present disclosure is not limited to such a configuration. For example, the fifth oil passage PS 5  may include an oil passage that supplies oil to the first rotating electrical machine MG 1  from both sides in the axial direction L, instead of the first inner oil passages  74   a . The sixth oil passage PS 6  may include an oil passage that supplies oil to the second rotating electrical machine MG 2  from both sides in the axial direction L, instead of the second inner oil passages  74   b.    
     (3) In the above embodiments, the configuration in which the third oil passage PS 3  includes the first outer oil passage  73   a  that supplies oil to the first rotating electrical machine MG 1  from the outer side in the radial direction R and the fourth oil passage PS 4  includes the second outer oil passage  73   b  that supplies oil to the second rotating electrical machine MG 2  from the outer side in the radial direction R is described by way of example. However, the present disclosure is not limited to such a configuration. For example, the third oil passage PS 3  may include an oil passage that supplies oil to the first rotating electrical machine MG 1  from both sides in the axial direction L, instead of the first outer oil passage  73   a . The fourth oil passage PS 4  may include an oil passage that supplies oil to the second rotating electrical machine MG 2  from both sides in the axial direction L, instead of the second outer oil passage  73   b.    
     (4) In the above embodiments, the configuration in which the second oil passage PS 2  includes the first supply passages  71   a  that supply oil to the first planetary gear mechanism PG 1  is described by way of example. However, the present disclosure is not limited to such a configuration. The second oil passage PS 2  may not include the first supply passages  71   a . The first transmission system T 1  may not include the first planetary gear mechanism PG 1 . 
     (5) In the above embodiments, the configuration in which the vehicle drive device includes the valve mechanism  8  that selectively supplies either the oil discharged from the first hydraulic pump  61  or the oil discharged from the second hydraulic pump  62  to the first inner oil passages  74   a  and the first supply passages  71   a  is described by way of example. However, the present disclosure is not limited to such a configuration. The vehicle drive device may not include the valve mechanism  8 . 
     (6) In the above embodiments, the configuration in which the first valve  81  and the second valve  82  of the valve mechanism  8  are check valves is described by way of example. However, the present disclosure is not limited to such a configuration. For example, the valve mechanism  8  may include a solenoid valve whose opening and closing is controlled using an electromagnet. 
     (7) In the second embodiment, the configuration in which the engagement device CL is a meshing engagement device is described by way of example. However, the present disclosure is not limited to such a configuration. For example, the engagement device CL may be a hydraulic friction engagement device in which the state of engagement between friction members is hydraulically controlled. 
     (8) In the second embodiment, the vehicle drive device  100  configured as a series-parallel hybrid vehicle drive including the engagement device CL that connects and disconnects the first transmission system T 1  and the second transmission system T 2  to and from each other is described by way of example. However, the present disclosure is not limited to this. The vehicle drive device  100  having a configuration similar to that of the second embodiment may not include the engagement device CL. In this configuration, the vehicle drive device  100  is what is called a series hybrid vehicle drive device. 
     (9) The configuration disclosed in each of the above embodiments can be applied in combination with any of the configurations disclosed in the other embodiments as long as no inconsistency arises. Regarding other configurations as well, the embodiments disclosed herein are merely illustrative in all respects. Accordingly, various modifications can be made as appropriate without departing from the spirit and scope of the present disclosure. 
     5. Outline of Embodiments 
     The outline of the vehicle drive device ( 100 ) described above will be described below. 
     The vehicle drive device ( 100 ) includes: 
     an input member ( 1 ) that is drivingly coupled to an internal combustion engine (EG); 
     an output member ( 5 ) that is drivingly coupled to wheels (W); 
     a first rotating electrical machine (MG 1 ) and a second rotating electrical machine (MG 2 ); 
     a first transmission system (T 1 ) that drivingly couples the first rotating electrical machine (MG 1 ) and the input member ( 1 ); 
     a second transmission system (T 2 ) that drivingly couples the second rotating electrical machine (MG 2 ) and the output member ( 5 ); 
     a first hydraulic pump ( 61 ) that is driven by a driving force transmitted through the second transmission system (T 2 ); 
     a second hydraulic pump ( 62 ) that is driven by a dedicated driving force source ( 62   a ), the dedicated driving force source ( 62   a ) being independent of the first transmission system (T 1 ) and the second transmission system (T 2 ); 
     a first oil passage (PS 1 ) that supplies oil discharged from the first hydraulic pump ( 61 ) to the second transmission system (T 2 ); 
     a second oil passage (PS 2 ) that supplies oil discharged from the second hydraulic pump ( 62 ) to the first transmission system (T 1 ); 
     a third oil passage (PS 3 ) that supplies the oil discharged from the second hydraulic pump ( 62 ) to the first rotating electrical machine (MG 1 ); and 
     a fourth oil passage (PS 4 ) that supplies the oil discharged from the second hydraulic pump ( 62 ) to the second rotating electrical machine (MG 2 ). 
     According to this configuration, oil is supplied to the second transmission system (T 2 ) by the first hydraulic pump ( 61 ) that is driven by the driving force transmitted through the second transmission system (T 2 ) that drivingly couples the second rotating electrical machine (MG 2 ) and the output member ( 5 ). Accordingly, oil can be appropriately supplied to the portion to which the driving force is transmitted when the vehicle is traveling by the driving force of the second rotating electrical machine (MG 2 ). Oil is also supplied to the first transmission system (T 1 ), the first rotating electrical machine (MG 1 ), and the second rotating electrical machine (MG 2 ) by the second hydraulic pump ( 62 ) that is driven by the independent dedicated driving force source ( 62   a ). Accordingly, when the vehicle is traveling by the driving force of the second rotating electrical machine (MG 2 ), the second rotating electrical machine (MG 2 ) can be cooled by the oil discharged from the second hydraulic pump ( 62 ). When the first rotating electrical machine (MG 1 ) generates electric power by the driving force of the internal combustion engine (EG) while the vehicle is stopped, the first transmission system (T 1 ) can be lubricated and the first rotating electrical machine (MG 1 ) can be cooled both by the oil discharged from the second hydraulic pump ( 62 ). That is, by controlling the discharge amount of the second hydraulic pump ( 62 ), an appropriate amount of oil can be supplied to the portions where oil is needed according to the operating state of each part, regardless of the traveling state of the vehicle. 
     As described above, according to this configuration, the oil discharged from the first hydraulic pump ( 61 ) and the second hydraulic pump ( 62 ) can be appropriately supplied to the portions of the vehicle drive device ( 100 ) where oil is needed, without using gear rotation. Oil can thus be stably supplied to each part regardless of the mounting angle of the vehicle drive device ( 100 ) on the vehicle, the sizes of the components of the second transmission system (T 2 ), etc. Therefore, according to this configuration, the vehicle drive device ( 100 ) with high robustness can be implemented. 
     According to this configuration, even while the internal combustion engine (EG) is stopped, oil is supplied to the second transmission system (T 2 ) by the first hydraulic pump ( 61 ) that is driven by the driving force transmitted through the second transmission system (T 2 ) that drivingly couples the second rotating electrical machine (MG 2 ) and the output member ( 5 ), when the vehicle is traveling by the driving force of the second rotating electrical machine (MG 2 ). That is, even while the internal combustion engine (EG) is stopped, the second transmission system (T 2 ) can be lubricated by the oil discharged from the first hydraulic pump ( 61 ). The discharge amount of the second hydraulic pump ( 62 ) therefore need not be large enough that the second hydraulic pump ( 62 ) that is driven by the independent dedicated driving force source ( 62   a ) can supply oil to the second transmission system (T 2 ) in addition the first rotating electrical machine (MG 1 ), the second rotating electrical machine (MG 2 ), and the first transmission system (T 1 ). As a result, manufacturing cost of the vehicle drive device ( 100 ) can be reduced. 
     It is preferable that the third oil passage (PS 3 ) include a first outer oil passage ( 73   a ) that supplies the oil to the first rotating electrical machine (MG 1 ) from an outer side in a radial direction (R), and 
     that the fourth oil passage (PS 4 ) include a second outer oil passage ( 73   b ) that supplies the oil to the second rotating electrical machine (MG 2 ) from the outer side in the radial direction (R). 
     According to this configuration, as compared to a configuration in which oil is supplied to the first rotating electrical machine (MG 1 ) and the second rotating electrical machine (MG 2 ) from an inner side in the radial direction (R), it is not necessary to use a centrifugal force of a rotation member, etc. to supply oil. The first outer oil passage ( 73   a ) and the second outer oil passage ( 73   b ) can therefore have a simple configuration. 
     It is preferable that the vehicle drive device further include a fifth oil passage (PS 5 ) that supplies the oil discharged from the first hydraulic pump ( 61 ) to the first rotating electrical machine (MG 1 ). 
     According to this configuration, oil can be supplied from the first hydraulic pump ( 61 ) to the first rotating electrical machine (MG 1 ) through the fifth oil passage (PS 5 ) when the vehicle is traveling. Therefore, in addition to supplying oil from the second hydraulic pump ( 62 ) to the first rotating electrical machine (MG 1 ) through the third oil passage (PS 3 ), oil can also be supplied from the first hydraulic pump ( 61 ) to the first rotating electrical machine (MG 1 ) through the fifth oil passage (PS 5 ). Load on the second hydraulic pump ( 62 ) can thus be reduced. Accordingly, the second hydraulic pump ( 62 ) can be reduced in size, and therefore reduction in size of the vehicle drive device ( 100 ) can be achieved. 
     In the configuration in which the vehicle drive device includes the fifth oil passage (PS 5 ), 
     it is preferable that the fifth oil passage (PS 5 ) include a first inner oil passage ( 74   a ) that supplies the oil to the first rotating electrical machine (MG 1 ) from an inner side in the radial direction R. 
     According to this configuration, oil can be supplied more easily widely in the first rotating electrical machine (MG 1 ) as compared to, e.g., a configuration in which oil is supplied to the first rotating electrical machine (MG 1 ) from the outer side in the radial direction R. 
     It is preferable that the vehicle drive device further include a sixth oil passage (PS 6 ) that supplies the oil discharged from the first hydraulic pump ( 61 ) to the second rotating electrical machine (MG 2 ). 
     According to this configuration, oil can be supplied from the first hydraulic pump ( 61 ) to the second rotating electrical machine (MG 2 ) through the sixth oil passage (PS 6 ) when the vehicle is traveling. Accordingly, when the vehicle is traveling by the driving force of the second rotating electrical machine (MG 2 ), not only oil can be supplied from the second hydraulic pump ( 62 ) to the second rotating electrical machine (MG 2 ) through the fourth oil passage (PS 4 ), but also oil can be supplied from the first hydraulic pump ( 61 ) to the second rotating electrical machine (MG 2 ) through the sixth oil passage (PS 6 ). Load on the second hydraulic pump ( 62 ) can thus be reduced. Accordingly, the second hydraulic pump ( 62 ) can be reduced in size, and therefore reduction in size of the vehicle drive device ( 100 ) can be achieved. 
     In the configuration in which the vehicle drive device includes the sixth oil passage (PS 6 ), 
     it is preferable that the sixth oil passage (PS 6 ) include a second inner oil passage ( 74   b ) that supplies the oil to the second rotating electrical machine (MG 2 ) from an inner side in a radial direction (R). 
     According to this configuration, oil can be supplied more easily widely in the second rotating electrical machine (MG 2 ) as compared to, e.g., a configuration in which oil is supplied to the second rotating electrical machine (MG 2 ) from the outer side in the radial direction R. 
     It is preferable that the first transmission system (T 1 ) include a distribution differential gear mechanism (PG 1 ) that distributes a driving force of the internal combustion engine (EG) transmitted to the input member ( 1 ) to the first rotating electrical machine (MG 1 ) and 
     the second transmission system (T 2 ), and that the second oil passage (PS 2 ) include a first supply passage ( 71   a ) that supplies the oil to the distribution differential gear mechanism (PG 1 ). 
     According to this configuration, the second hydraulic pump ( 62 ) that is driven by the dedicated driving force source ( 62   a ) independent of the first transmission system (T 1 ) and the second transmission system (T 2 ) supplies oil to the distribution differential gear mechanism (PG 1 ) through the first supply passage ( 71   a ). Oil can thus be appropriately supplied to the distribution differential gear mechanism (PG 1 ) regardless of the traveling state of the vehicle. 
     In the configuration in which the fifth oil passage (PS 5 ) includes the first inner oil passage ( 74   a ), it is preferable that 
     the first transmission system (T 1 ) include a distribution differential gear mechanism (PG 1 ) that distributes a driving force of the internal combustion engine (EG) transmitted to the input member ( 1 ) to the first rotating electrical machine (MG 1 ) and the second transmission system (T 2 ), 
     the second oil passage (PS 2 ) include a first supply passage ( 71   a ) that supplies the oil to the distribution differential gear mechanism (PG 1 ), and 
     the vehicle drive device further include a valve mechanism ( 8 ) that selectively supplies either the oil discharged from the first hydraulic pump ( 61 ) or the oil discharged from the second hydraulic pump ( 62 ) to the first inner oil passage ( 74   a ) and the first supply passage ( 71   a ). 
     According to this configuration, oil is supplied to the first inner oil passage ( 74   a ) and the first supply passage ( 71   a ) from either the first hydraulic pump ( 61 ) or the second hydraulic pump ( 62 ), whichever is appropriate. The amount of oil that is discharged from the other hydraulic pump can therefore be reduced. Energy consumption of the first hydraulic pump ( 61 ) and the second hydraulic pump ( 62 ) can thus be reduced, and energy efficiency of the vehicle drive device ( 100 ) can be increased. 
     In the configuration in which the vehicle drive device includes the valve mechanism ( 8 ), the first transmission system (T 1 ) includes the distribution differential gear mechanism (PG 1 ), and the second oil passage (PS 2 ) includes the first supply passage ( 71   a ), it is preferable that 
     the distribution differential gear mechanism (PG 1 ) include a first rotation element (C 1 ) drivingly coupled to the input member ( 1 ), a second rotation element (S 1 ) drivingly coupled to the first rotating electrical machine (MG 1 ), and a third rotation element (R 1 ), 
     the second transmission system (T 2 ) include: a first gear ( 2 ) coupled to the third rotation element (R 1 ) so as to rotate integrally with the third rotation element (R 1 ); a speed reducer (PG 2 ) that reduces a speed of rotation of the second rotating electrical machine (MG 2 ) to transmit the resultant rotation to the first gear ( 2 ); a counter gear mechanism ( 3 ) having a second gear ( 31 ) meshing with the first gear ( 2 ), and a third gear ( 32 ) that rotates integrally with the second gear ( 31 ); and an output differential gear mechanism ( 4 ) that has a fourth gear ( 41 ) meshing with the third gear ( 32 ) and that distributes rotation of the fourth gear ( 41 ) to a pair of output units ( 51 ), the output units ( 51 ) being the output member ( 5 ), 
     the first oil passage (PS 1 ) include a second supply passage ( 71   b ) that supplies the oil to the speed reducer (PG 2 ), 
     the first rotating electrical machine (MG 1 ), the second rotating electrical machine (MG 2 ), the distribution differential gear mechanism (PG 1 ), and the speed reducer (PG 2 ) be coaxially arranged, 
     the first inner oil passage ( 74   a ), the first supply passage ( 71   a ), the second supply passage ( 71   b ), and an axis oil passage ( 75 ) be disposed inward of the first rotating electrical machine (MG 1 ), the second rotating electrical machine (MG 2 ), the distribution differential gear mechanism (PG 1 ), and the speed reducer (PG 2 ) in the radial direction (R), the axis oil passage ( 75 ) communicating with the first inner oil passage ( 74   a ), the first supply passage ( 71   a ), and the second supply passage ( 71   b ), and 
     the valve mechanism ( 8 ) selectively supply either the oil discharged from the first hydraulic pump ( 61 ) or the oil discharged from the second hydraulic pump ( 62 ) to the axis oil passage ( 75 ). 
     According to this configuration, the axis oil passage ( 75 ) is provided which communicates with the first inner oil passage ( 74   a ) of the fifth oil passage (PS 5 ), the first supply passage ( 71   a ) of the second oil passage (PS 2 ), and the second supply passage ( 71   b ) of the first oil passage (PS 1 ). That is, the axis oil passage ( 75 ) is provided as a common part of the first oil passage (PS 1 ), the second oil passage (PS 2 ), and the fifth oil passage (PS 5 ). The space for disposing the first oil passage (PS 1 ), the second oil passage (PS 2 ), and the fifth oil passage (PS 5 ) can thus be reduced. This makes it easier to achieve reduction in size of the vehicle drive device ( 100 ). 
     According to this configuration, the valve mechanism ( 8 ) selectively supplies either the oil discharged from the first hydraulic pump ( 61 ) or the oil discharged from the second hydraulic pump ( 62 ) to the axis oil passage ( 75 ). Oil is thus supplied to the axis oil passage ( 75 ) from either the first hydraulic pump ( 61 ) or the second hydraulic pump ( 62 ), whichever is appropriate. The amount of oil that is discharged from the other hydraulic pump can therefore be reduced. Energy consumption of the first hydraulic pump ( 61 ) and the second hydraulic pump ( 62 ) can thus be reduced, and energy efficiency of the vehicle drive device ( 100 ) can be increased. 
     In the configuration in which the vehicle drive device includes the valve mechanism ( 8 ) and the sixth oil passage (PS 6 ), the first transmission system (T 1 ) includes the distribution differential gear mechanism (PG 1 ), the second oil passage (PS 2 ) includes the first supply passage ( 71   a ), and the sixth oil passage (PS 6 ) includes the second inner oil passage ( 74   b ), it is preferable that the distribution differential gear mechanism (PG 1 ) include a first rotation element (C 1 ) drivingly coupled to the input member ( 1 ), a second rotation element (S 1 ) drivingly coupled to the first rotating electrical machine (MG 1 ), and a third rotation element (R 1 ), 
     the second transmission system (T 2 ) include: a first gear ( 2 ) coupled to the third rotation element (R 1 ) so as to rotate integrally with the third rotation element (R 1 ); a counter gear mechanism ( 3 ) having a second gear ( 31 ) meshing with the first gear ( 2 ), and a third gear ( 32 ) that rotates integrally with the second gear ( 31 ); an output differential gear mechanism ( 4 ) that has a fourth gear ( 41 ) meshing with the third gear ( 32 ) and that distributes rotation of the fourth gear ( 41 ) to a pair of output units ( 51 ), the output units ( 51 ) being the output member ( 5 ); and a fifth gear (RG 2 ) that rotates integrally with a rotor (Ro 2 ) of the second rotating electrical machine (MG 2 ) and that meshes with the first gear ( 2 ), 
     the first transmission system (T 1 ) include a sixth gear ( 9 ) that rotates integrally with the second rotation element (S 1 ), and a seventh gear (RG 1 ) that rotates integrally with a rotor (Ro 1 ) of the first rotating electrical machine (MG 1 ) and that meshes with the sixth gear ( 9 ), 
     the first rotating electrical machine (MG 1 ), the second rotating electrical machine (MG 2 ), the distribution differential gear mechanism (PG 1 ), the counter gear mechanism ( 3 ), and the output differential gear mechanism ( 4 ) be disposed on different axes from each other, 
     the first inner oil passage ( 74   a ) and a first axis oil passage ( 75 A) communicating with the first inner oil passage ( 74   a ) be disposed inward of the first rotating electrical machine (MG 1 ) in the radial direction (R), 
     the second inner oil passage ( 74   b ) and a second axis oil passage ( 75 B) communicating with the second inner oil passage ( 74   b ) be disposed inward of the second rotating electrical machine (MG 2 ) in the radial direction (R), 
     the first supply passage ( 71   a ) and a third axis oil passage ( 75 C) communicating with the first supply passage ( 71   a ) be disposed inward of the distribution differential gear mechanism (PG 1 ) in the radial direction (R), and 
     the valve mechanism ( 8 ) selectively supply either the oil discharged from the first hydraulic pump ( 61 ) or the oil discharged from the second hydraulic pump ( 62 ) to the first axis oil passage ( 75 A) and the third axis oil passage ( 75 C). 
     According to this configuration, the valve mechanism ( 8 ) selectively supplies either the oil discharged from the first hydraulic pump ( 61 ) or the oil discharged from the second hydraulic pump ( 62 ) to the first axis oil passage ( 75 A) and the third axis oil passage ( 75 C). Oil is thus supplied to the first axis oil passage ( 75 A) and the third axis oil passage ( 75 C) from either the first hydraulic pump ( 61 ) or the second hydraulic pump ( 62 ), whichever is appropriate. The amount of oil that is discharged from the other hydraulic pump can therefore be reduced. Energy consumption of the first hydraulic pump ( 61 ) and the second hydraulic pump ( 62 ) can thus be reduced, and energy efficiency of the vehicle drive device ( 100 ) can be increased. 
     According to this configuration, oil is not supplied to the second axis oil passage ( 75 B) through the valve mechanism ( 8 ). The oil discharged from the second hydraulic pump ( 62 ) is therefore not supplied to the second axis oil passage ( 75 B). Load on the second hydraulic pump ( 62 ) can thus be reduced. Accordingly, the second hydraulic pump ( 62 ) can be reduced in size, and therefore reduction in size of the vehicle drive device ( 100 ) can be achieved. 
     INDUSTRIAL APPLICABILITY 
     The technique according to the present disclosure is applicable to vehicle drive devices including: an input member that is drivingly coupled to an internal combustion engine; a pair of output members that is drivingly coupled to wheels; a first rotating electrical machine and a second rotating electrical machine; a first transmission system that drivingly couples the first rotating electrical machine and the input member; a second transmission system that drivingly couples the second rotating electrical machine and the pair of output members; and a first hydraulic pump and a second hydraulic pump. 
     DESCRIPTION OF THE REFERENCE NUMERALS 
     
         
         
           
               100 : vehicle drive device 
               1 : input member 
               5 : output member 
               61 : first hydraulic pump 
               62 : second hydraulic pump 
               62   a : electric motor (dedicated driving force source) 
             EG: internal combustion engine 
             MG 1 : first rotating electrical machine 
             MG 2 : second rotating electrical machine 
             W: wheel 
             T 1 : first transmission system 
             T 2 : second transmission system 
             PS 1 : first oil passage 
             PS 2 : second oil passage 
             PS 3 : third oil passage 
             PS 4 : fourth oil passage