Drive unit

Abstract

A case (1) for housing a dynamo-electric machine (2) and an inverter device (INV) is provided with an inflow port (11) into which a cooling liquid flows and a distribution path (4) through which the cooling liquid is distributed. The distribution path (4) is provided with a first heat exchange unit (41) for exchanging heat between the inverter device (INV) and the cooling liquid, and a turbine arrangement unit (43) in which a turbine (7) is arranged. The turbine (7) rotates by the flow of the cooling liquid that passes through the turbine arrangement unit (43), a pump rotor (88) of an oil pump (8) for discharging oil supplied to the dynamo-electric machine (2) being drive-connected to the turbine (7).

Description

[Technical field]

[0001] The present invention relates to a drive device including a rotating electric machine, an inverter, a case, and an oil pump. [Background technology]

[0002] JP 2019-129608 A discloses a drive device (14) for a vehicle in which an electric oil pump (44) is installed in addition to a mechanical oil pump (40) in a case (18) that houses a rotating electric machine (12) in order to supply cooling oil to the coil ends (12e) of the rotating electric machine (12) (reference numerals in parentheses in the Background Art are those of the referenced documents). In this drive device (14), by driving the electric oil pump (44) in accordance with the temperature of the rotating electric machine (12), when cooling of the rotating electric machine (12), such as the coil ends (12e), is required, cooling oil can be appropriately supplied regardless of the rotation state of the rotating members in the drive device (14) that are the drive source of the mechanical oil pump (14). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2019-129608 A Summary of the Invention [Problem to be solved by the invention]

[0004] As described above, providing a separate electric oil pump for cooling purposes leads to increased costs and larger dimensions of the drive unit.

[0005] It is therefore desirable to supply oil to the rotating electric machine at an appropriate timing while suppressing increases in the cost and size of the drive device. [Means for solving the problem]

[0006] In consideration of the above problems, a drive device comprising a rotating electric machine, an inverter that drives the rotating electric machine, a case that houses the rotating electric machine and the inverter, and an oil pump that discharges oil to be supplied to the rotating electric machine, wherein the case has a flow passage through which a coolant flows, and the flow passage has a first heat exchange section in which heat exchange between the inverter and the coolant takes place, and a turbine arrangement section in which a turbine is arranged, the turbine rotates by the flow of coolant passing through the turbine arrangement section, and a pump rotor of the oil pump is drivingly connected to the turbine.

[0007] According to this configuration, the flow of the coolant rotates the turbine, and the rotation of the turbine drives the pump rotor. This simplifies the configuration of the oil pump compared to a configuration that includes a separate drive source for the oil pump, such as an electric oil pump. Furthermore, compared to a configuration in which the oil pump is driven using the driving force of the rotating electric machine, a power transmission mechanism between the rotating electric machine and the oil pump is not required, and loss of the driving force of the rotating electric machine to drive the oil pump can be avoided. Furthermore, since the inverter is likely to generate heat when power is supplied to the rotating electric machine, it is often necessary to cool the rotating electric machine when the inverter needs to be cooled. According to this configuration, when the inverter is cooled by the coolant, the oil pump can be driven by the coolant to supply oil to the rotating electric machine, thereby cooling the rotating electric machine. This allows both the inverter and the rotating electric machine to be appropriately cooled at the appropriate time. In this way, according to this configuration, oil can be supplied to the rotating electric machine at the appropriate time while suppressing an increase in cost and an increase in size of the drive device.

[0008] Further features and advantages of the drive device will become apparent from the following description of an exemplary and non-limiting embodiment, which is given with reference to the drawings, in which: [Brief description of the drawings]

[0009] [Figure 1] FIG. 1 is a schematic cross-sectional view showing an example of a driving device; [Diagram 2]A skeleton diagram showing an example of a drive mechanism [Diagram 3] FIG. 1 is a diagram showing an example of the configuration of an oil pump and an example of the flow paths of oil and coolant; [Figure 4] FIG. 1 is a diagram showing an example of an oil pump configuration and another example of a flow path of oil and a coolant; DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, an embodiment of the drive device will be described with reference to the drawings, taking a vehicle drive device mounted on a vehicle to drive the wheels as an example. The directions of each member in the following description refer to the directions when the drive device 100 is assembled to the vehicle (mounted on the vehicle). Furthermore, terms related to the dimensions, arrangement direction, arrangement position, and the like of each member are concepts that include a state in which there is a difference due to an error (an error that can be tolerated in manufacturing). In the vehicle mounted state, the direction along the rotation axis of the drive device 100 (the first axis A1, the second axis A2, and the third axis A3, which are parallel to each other in this embodiment, and will be described in detail later) is referred to as the axial direction L. Moreover, one side in the axial direction L is referred to as the axial first side L1, and the other side is referred to as the axial second side L2. Moreover, the directions perpendicular to each of the first axis A1, the second axis A2, and the third axis A3 are referred to as the "radial direction" based on each axis. Moreover, the direction along the vertical direction when the drive device 100 is mounted on the vehicle is referred to as the "up-down direction V". In addition, when indicating the up and down directions, they are referred to as the up V1 and down V2, respectively. When the drive unit 100 is attached to the vehicle with the axial direction L parallel to the horizontal plane, one radial direction and the up and down direction V coincide with each other.

[0011] As shown in FIG. 1 and FIG. 2, the drive device 100 includes a rotating electric machine 2, a transmission mechanism 3 that transmits power between the rotating electric machine 2 and a wheel W, and a case 1 that accommodates the rotating electric machine 2 and the transmission mechanism 3. In this embodiment, the rotating electric machine 2 is a drive source that drives the wheel W. In this embodiment, the transmission mechanism 3 includes a differential gear mechanism DF that is drivably connected to the wheel W, a counter gear mechanism CG that drivably connects the rotating electric machine 2 and the differential gear mechanism DF, and an input gear IG that drivably connects the rotating electric machine 2 and the counter gear mechanism CG. As described later, the differential gear mechanism DF is disposed on the first axis A1 together with the wheel W. The rotating electric machine 2 is disposed on the second axis A2, which is another axis parallel to the first axis A1, together with the input gear IG. The counter gear mechanism CG is disposed on the third axis A3 that is parallel to the first axis A1 and the second axis A2.

[0012] The rotating electric machine 2 is a rotating electric machine (Motor / Generator) that operates, for example, by a multi-phase AC (for example, a three-phase AC) and can function as both an electric motor and a generator. The rotating electric machine 2 receives power from a DC power source (not shown) for power running, or supplies (regenerates) power generated by the inertial force of the vehicle to the DC power source. The rotating electric machine 2 is driven and controlled by an inverter device INV (inverter). In this embodiment, as shown in FIG. 1, the inverter device INV is also housed in the case 1. The inverter device INV includes an inverter circuit (not shown) that converts power between DC power and multi-phase AC power. The inverter circuit is connected to the AC rotating electric machine 2 and the DC power source, and converts power between multi-phase (for example, three-phase) AC and DC. The DC power source is composed of, for example, a secondary battery (battery) such as a nickel-metal hydride battery or a lithium-ion battery, an electric double layer capacitor, or the like. When the rotating electric machine 2 is a drive source for a vehicle, the rated power supply voltage of the DC power supply is, for example, 200 to 400 [V].

[0013] The inverter circuit is configured to have a plurality of switching elements. As the switching elements, it is preferable to apply power semiconductor elements capable of operating at high frequencies, such as IGBT (Insulated Gate Bipolar Transistor), power MOSFET (Metal Oxide Semiconductor Field Effect Transistor), SiC-MOSFET (Silicon Carbide - Metal Oxide Semiconductor FET), SiC-SIT (SiC - Static Induction Transistor), and GaN-MOSFET (Gallium Nitride - MOSFET). For example, the inverter circuit is configured to be integrated into one power module including a freewheel diode. In addition, the DC side of the inverter circuit is provided with a DC link capacitor (smoothing capacitor) that smoothes the voltage between the positive and negative poles (DC link voltage).

[0014] The inverter circuit is controlled by an inverter control device (not shown). The inverter control device is constructed with a logic circuit such as a microcomputer as a core component, and drives and controls the rotating electric machine 2 via the inverter circuit by, for example, current feedback control. The microcomputer and other components constituting the inverter control device are supplied with power from a low-voltage DC power source having a lower voltage (for example, 12 to 24 [V]) than the DC power source connected to the inverter circuit and operate. For this reason, the inverter control device is provided with a drive circuit that enhances and relays the drive capability (for example, the capability to operate a downstream circuit, such as voltage amplitude or output current) of the switching control signal (gate drive signal in the case of IGBT) for each switching element. The inverter control device is configured by mounting the above-mentioned microcomputer, its peripheral circuits, and circuit components constituting the drive circuit on one or more boards.

[0015] The inverter unit INV includes at least an inverter circuit (power module). In this embodiment, the inverter unit INV is configured as a unit including the inverter control device, the DC link capacitor, and the inverter circuit (power module) as described above. As will be described later, the inverter unit INV is disposed in the second housing portion E2 inside the case 1, and is fixed to the case 1 by fastening members such as bolts.

[0016] The rotating electric machine 2 has a stator 23 fixed to the case 1 or the like, and a rotor 21 rotatably supported on the radial inside of the stator 23. In this embodiment, the stator 23 includes a stator core 22 and a stator coil 24 wound around the stator core 22, and the rotor 21 includes a rotor core and a permanent magnet arranged on the rotor core. The rotor 21 of the rotating electric machine 2 is connected to a rotor shaft 20 that rotates integrally with the rotor 21. An input shaft XI is connected to the rotor shaft 20 so as to rotate integrally with the rotor shaft 20. The rotor shaft 20 is rotatably supported by the case 1 via a rotor bearing B2, and the input shaft XI is rotatably supported by the case 1 via an input bearing B1. An input gear IG is provided on the input shaft XI so as to rotate integrally with the input shaft XI. The input gear IG is meshed with a first counter gear CG1 of a counter gear mechanism CG, as described later. That is, the input gear IG functions as a part of the transmission mechanism, rotates integrally with the rotor 21, and transmits the driving force of the rotating electric machine 2 to the counter gear mechanism CG.

[0017] The differential gear mechanism DF is disposed on the first shaft A1 and distributes the driving force transmitted from the rotating electric machine 2 to a pair of wheels W. The differential gear mechanism DF includes a plurality of bevel gears meshing with each other and a differential case DC that houses the plurality of bevel gears. The differential gear mechanism DF distributes and transmits the rotation and torque input to the differential input gear DG1 from the rotating electric machine 2 to a pair of output shafts XO via a pair of side gears DG3 that mesh with a pinion gear DC2 that is disposed along the radial direction and rotatably supported on a pinion shaft DA that rotates integrally with the differential input gear DG1. In this embodiment, the first wheel W1 is connected to the first output shaft XO1 on the axial first side L1 of the differential gear mechanism DF, and the second wheel W2 is connected to the second output shaft XO2 on the axial second side L2. The first output shaft XO1 is rotatably supported by the case 1 via a first output bearing B5, and the second output shaft XO2 is rotatably supported by the case 1 via a second output bearing B4 (see FIG. 2).

[0018] The counter gear mechanism CG is disposed on the third shaft A3, and drivingly connects the rotating electric machine 2 and the differential gear mechanism DF via the input gear IG. In this embodiment, the counter gear mechanism CG has a first counter gear CG1 and a second counter gear CG2 connected by a counter shaft XC. That is, the counter gear mechanism CG is disposed on the third shaft A3, and includes a first counter gear CG1 that meshes with the input gear IG, and a second counter gear CG2 that rotates integrally with the first counter gear CG1 and meshes with the differential input gear DG1. The counter shaft XC is rotatably supported on the case 1 by a counter bearing B3.

[0019] As described above, in this embodiment, the power transmission path connecting the rotating electric machine 2 and the wheels W includes, in order from the rotating electric machine 2 side, an input gear IG, a counter gear mechanism CG, and a differential gear mechanism DF as the transmission mechanism 3.

[0020] In this embodiment, as shown in FIG. 1, the case 1 includes a first housing portion E1 that houses the rotating electric machine 2 and a second housing portion E2 that houses the inverter unit INV. In this embodiment, the first housing portion E1 and the second housing portion E2 are integrally formed. That is, the case 1 is configured to have a main body portion that is integrally formed with the first housing portion E1 that houses the rotating electric machine 2 (including the transmission mechanism 3) and the second housing portion E2 that houses the inverter unit INV. Here, "integrally formed" refers to an integral member formed of a common material, for example, as a single die casting.

[0021] Incidentally, in a rotating electric machine 2 serving as a drive source for wheels W, a large current flows through the stator coil 24, and the electric resistance of the stator coil 24 tends to cause large heat generation. As described above, the stator coil 24 is wound around the stator core 22, and at the end of the stator 23 in the axial direction L, a coil end portion 24e is formed where a bent portion of the wound stator coil 24 protrudes from the stator core 22 in the axial direction L. The stator coil 24 is often cooled by applying a refrigerant to the coil end portion 24e. The stator coil 24 is naturally an electrical conductor, and a non-conductive fluid, such as oil, is used as the refrigerant.

[0022] In order to supply oil to the stator coil 24 (coil end portion 24e) inside the case 1, for example, an oil pump may be installed inside the case 1. If a mechanical oil pump such as a trochoid pump driven by a rotating member inside the drive unit 100 is installed as such an oil pump, the supply of oil may be affected by the rotation state of the rotating member, and oil may not be properly supplied when cooling is required. Therefore, for example, if an electric oil pump is separately installed for cooling, the cost of the drive unit 100 increases and the size increases. The drive unit 100 of this embodiment is characterized in that it is configured with an oil pump 8 that can supply oil to the rotating electric machine 2 at an appropriate timing while suppressing the cost increase and size increase of the drive unit 100. Hereinafter, an example of the configuration of the oil pump 8 and an example of the flow path of the oil and the coolant will be described with reference to FIG. 3.

[0023] As shown in FIG. 1, the drive device 100 of the present embodiment includes a rotating electric machine 2, an inverter device INV that drives the rotating electric machine 2, a case 1 that houses the rotating electric machine 2 and the inverter device INV, and an oil pump 8 that discharges oil to be supplied to the rotating electric machine 2. As shown in FIG. 3, the case 1 includes an inlet 11 through which the coolant flows in, an outlet 12 through which the coolant flows out, and a flow passage 4 through which the coolant flows. Here, the flow passage 4 through which the coolant flows between the inlet 11 and the outlet 12 is illustrated, but the entire flow passage 4 does not have to be disposed inside the case 1. For example, a part of the flow passage 4 may be disposed outside the case 1. The flow passage 4 includes a first heat exchange section 41 in which heat exchange between the inverter device INV and the coolant is performed, and a turbine arrangement section 43 in which a turbine 7 is arranged. The turbine 7 rotates by the flow of the coolant passing through the turbine arrangement section 43. A pump rotor 88 of the oil pump 8 is drivingly connected to the turbine 7, and the pump rotor 88 is driven by the rotation of the turbine 7. Note that, although Fig. 3 illustrates an example in which the turbine 7 is disposed inside the case 1, the turbine 7 may be disposed outside the case 1 when a portion of the flow passage 4 is disposed outside the case 1.

[0024] In this embodiment, the pump rotor 88 is driven by the turbine 7 that rotates due to the flow of the cooling liquid. Therefore, the configuration of the oil pump 8 can be simplified compared to a configuration in which a separate driving source for the pump is provided, such as an electric oil pump. In addition, compared to a configuration in which the pump is driven using the driving force of the rotating electric machine 2, for example, a power transmission mechanism between the rotating electric machine 2 and the oil pump 8 is not required, and the loss of the driving force of the rotating electric machine 2 to drive the oil pump 8 can be avoided. In addition, since the inverter unit INV is likely to generate heat when power is supplied to the rotating electric machine 2, it is often necessary to cool the rotating electric machine 2 when the inverter unit INV needs to be cooled. In this embodiment, both the inverter unit INV and the rotating electric machine 2 can be appropriately cooled at an appropriate time. That is, in this embodiment, in a situation in which the inverter unit INV is cooled by the cooling liquid, the flow of the cooling liquid can be used to drive the oil pump 8 to supply oil to the rotating electric machine 2, thereby cooling the rotating electric machine 2.

[0025] As shown in FIG. 1, the turbine 7 and the pump rotor 88 are connected via a pump shaft 80. The pump shaft 80 is rotatably supported by the case 1, and the turbine 7 and the pump rotor 88 are each connected to the pump shaft 80 so as to rotate integrally with the pump shaft 80. When the turbine 7 rotates due to the cooling water, the pump rotor 88 also rotates together with the pump shaft 80. The turbine chamber 70 in which the turbine 7 is disposed and the pump chamber 60 in which the pump rotor 88 is disposed are kept liquid-tight by a seal member so that the coolant and the oil do not mix. In this example, a turbine side seal member 75 is disposed on the turbine chamber 70 side, and a pump side seal member 85 is disposed on the pump chamber 60 side.

[0026] 3, the oil pump 8 is connected to the oil reservoir P via a first oil passage 61, and is connected to a target space S, which is a space in which a supply target to which oil is to be supplied is disposed, via a second oil passage 62. In other words, the first oil passage 61 is the oil passage 6 that communicates between the intake port 81 of the oil pump 8 and the oil reservoir P, and the second oil passage 62 is the oil passage 6 that communicates between the discharge port 82 of the oil pump 8 and the target space S.

[0027] Here, the oil reservoir P refers to an oil pan (oil reservoir) formed at the bottom of the case 1, or a catch tank disposed at a position V1 above the oil pan in the case 1. The oil pan stores oil that descends due to gravity at the bottom of the case 1. The oil stored in the oil pan is scooped up by any of the rotating members constituting the transmission mechanism 3, and lubricates the bearings B, such as the input bearing B1, the counter bearing B3, the first output bearing B5, and the second output bearing B4. The catch tank receives the scooped up oil before it falls into the oil pan and temporarily stores it therein. Although a catch tank is illustrated as an example of the oil reservoir P in FIG. 3, the oil reservoir P may, of course, be an oil pan.

[0028] In this embodiment, the targets to which oil is supplied include the coil end portion 24e of the stator coil 24. In this case, the target space S corresponds to the space in which the coil end portion 24e is arranged. As shown in FIG. 1, the rotor bearing B2 is arranged at a position overlapping the coil end portion 24e when viewed in the up-down direction, and the coil end portion 24e can be lubricated by the falling oil that has cooled the coil end portion 24e. Therefore, the rotor bearing B2 can also be a target to which oil is supplied, and the arrangement space of the rotor bearing B2 can also be the target space S. Naturally, other bearings B, meshing gears, etc. can also be supply targets, and the arrangement spaces thereof can be the target spaces S.

[0029] The oil pressure of the oil discharged by the oil pump 8, which uses the turbine 7 rotated by the coolant as a driving force source, is sufficient if it is high enough to guide the oil through the second oil passage 62 to the target space S. For example, a lower oil pressure than that required to drive a friction engagement device or the like is sufficient. Therefore, with such a simple configuration, the oil pump 8 can be configured on a small scale.

[0030] 1, an oil supply port 62a for supplying oil to the target space S (coil end portion 24e) is provided inside the case 1. The discharge port 82 of the oil pump 8 is in communication with the oil supply port 62a via the second oil passage 62. The oil supply port 62a is disposed in correspondence with the coil end portion 24e of the stator coil 24, and is made of a non-conductive member Z.

[0031] As described above, a high voltage is applied to the stator coil 24. Since the oil supply port 62a is made of the non-conductive member Z, the oil supply port 62a can be disposed close to the stator coil 24 while reducing the possibility of a short circuit. Therefore, the stator coil 24 can be effectively cooled by oil. Furthermore, since heat generation in the inverter device INV and the stator coil 24 often occurs at the same time, cooling by oil can be efficiently performed by utilizing the flow of cooling water.

[0032] Incidentally, the faster the flow rate of the cooling water, the greater the cooling effect. Also, since the flow passage 4 acts as a resistance to the cooling water, it is preferable that the flow passage 4 is arranged as short as possible. In the drive unit 100 of this embodiment, the flow passage 4 is configured to be short as described below.

[0033] In this embodiment, as shown in Figures 1 and 3, both the oil pump 8 and the turbine 7 are disposed within the case 1. Although not shown in the drawings, it is preferable that at least one of the oil pump 8 and the turbine 7 is disposed within the case 1. When the oil pump 8 is disposed within the case 1, it is easier to shorten the oil passage 6 from the oil pump 8 to the rotating electrical machine 2 compared to a configuration in which the oil pump 8 is disposed outside the case 1. Also, when the turbine 7 is disposed within the case 1, it is easier to shorten the flow passage compared to a configuration in which the turbine 7 is disposed outside the case 1.

[0034] As described above, the case 1 includes the first housing portion E1 that houses the rotating electric machine 2 and the second housing portion E2 that houses the inverter device INV, and the first housing portion E1 and the second housing portion E2 are integrally formed. Therefore, it is easier to shorten the flow passage 4 compared to a configuration in which the first housing portion E1 and the second housing portion E2 are separate.

[0035] 3, in this embodiment, the drive unit 100 also includes a second heat exchanger 42 in which heat exchange is performed between the oil stored in the oil storage unit P provided in the case 1 and the coolant. The flow passage 4 of the coolant is formed so that the coolant flows from the cooling water storage unit Q through the inlet 11, the first heat exchanger 41, the second heat exchanger 42, and the turbine arrangement unit 43 in the order described above, and returns from the outlet 12 to the cooling water storage unit Q. In other words, the first heat exchanger 41, the second heat exchanger 42, and the turbine arrangement unit 43 are arranged in this order along the flow passage 4 from the inlet 11 to the outlet 12, that is, from the upstream side to the downstream side, in the order of the first heat exchanger 41, the second heat exchanger 42, and the turbine arrangement unit 43.

[0036] As described above, the first heat exchange unit 41 cools the inverter unit INV by exchanging heat with the inverter unit INV. Furthermore, by providing the second heat exchange unit 42, the oil can be cooled by exchanging heat with the oil stored in the oil reservoir P. That is, both the oil in the case 1 and the inverter unit INV can be cooled by the coolant. As described above, the oil stored in the oil reservoir P is supplied to the coil end portion 24e of the rotating electric machine 2 by the oil pump 8. By supplying the oil cooled by the coolant to the rotating electric machine 2, the rotating electric machine 2 can also be effectively cooled.

[0037] On the other hand, when the cooling liquid rotates the turbine 7, the flow rate of the cooling liquid decreases. Heat exchange is more effectively performed when the flow rate of the cooling liquid is faster. The first heat exchange section 41 and the second heat exchange section 42 are arranged upstream of the turbine arrangement section 43 in the flow passage 4. Therefore, cooling can be efficiently performed in the first heat exchange section 41 and the second heat exchange section 42 before the flow rate decreases due to the rotation of the turbine 7. In addition, since the cooling liquid passes through the first heat exchange section 41 before the second heat exchange section 42, the inverter device INV can be appropriately cooled by the cooling liquid before its temperature increases by absorbing heat from the hot oil. In other words, the inverter device INV can be cooled by the cooling liquid with a higher cooling capacity. In many cases, the cooling water storage section Q is configured to have a function of dissipating heat from the cooling water. Therefore, the cooling liquid is cooled by the cooling water and then supplied to the drive device 100, where it can effectively cool the inverter, then cool the oil, and drive the turbine 7.

[0038] As described above, according to this embodiment, it is possible to supply oil to the rotating electric machine at an appropriate timing while suppressing increases in the cost and size of the drive device.

[0039] Other embodiments Other embodiments will be described below. Note that the configurations of the embodiments described below are not limited to being applied independently, and may be applied in combination with the configurations of other embodiments as long as no contradiction occurs.

[0040] (1) In the above, the first housing portion E1 housing the rotating electric machine 2 and the second housing portion E2 housing the inverter unit INV are integrally formed. However, this does not preclude a configuration in which these are formed as separate bodies and are integrated by being fastened together with, for example, a fastening member or the like.

[0041] (2) In the above, an example has been given in which the turbine 7 and the pump rotor 88 are connected to rotate integrally via the pump shaft 80. However, the turbine 7 and the pump rotor 88 may be connected to each other so long as they rotate in unison, and may be drivingly connected, for example, via a gear mechanism, a chain, a belt, or the like. In addition, the turbine 7 and the pump rotor 88 may be connected by a non-contact connecting means such as a magnetic coupling.

[0042] (3) In the above, an embodiment has been described in which at least one of the oil pump 8 and the turbine 7 is disposed inside the case 1. However, as long as the turbine 7 is rotated by the cooling water and the pump rotor 88 is driven by the turbine 7, a configuration in which both the oil pump 8 and the turbine 7 are disposed outside the case 1 is not prohibited.

[0043] (4) In the above, the oil supply port 62a is disposed opposite the stator coil 24 and is made of the non-conductive member Z. However, the oil supply port 62a may be integral with the case 1. For example, the oil supply port 62a may be made of a conductive member. In this case, it is preferable that the oil supply port 62a is disposed away from the stator coil 24 to ensure an insulation distance.

[0044] (5) In the above, the flow passage 4 includes the first heat exchange section 41 and the second heat exchange section 42. However, the flow passage 4 may include the first heat exchange section 41 and the turbine arrangement section 43 without including the second heat exchange section 42. In this case, it is preferable that the first heat exchange section 41 and the turbine arrangement section 43 are arranged in this order from the upstream side to the downstream side along the flow passage 4. However, this does not prevent them from being arranged in the reverse order.

[0045] (6) In the above, when the flow passage 4 includes the first heat exchange section 41, the second heat exchange section 42, and the turbine arrangement section 43, the first heat exchange section 41, the second heat exchange section 42, and the turbine arrangement section 43 are arranged in this order from the upstream side to the downstream side along the flow passage 4. If the turbine arrangement section 43 is arranged on the upstream side of the flow passage 4, the flow rate of the coolant is reduced, which may reduce the cooling efficiency on the downstream side. However, if the cooling performance sufficiently satisfies the required specifications even if the flow rate is reduced, the turbine arrangement section 43 may be arranged on the upstream side of either or both of the first heat exchange section 41 and the second heat exchange section 42. Similarly, the order of the first heat exchange section 41 and the second heat exchange section 42 may be reversed.

[0046] (7) In the above, referring to FIG. 3, when the flow passage 4 includes the first heat exchange section 41, the second heat exchange section 42, and the turbine arrangement section 43, the first heat exchange section 41, the second heat exchange section 42, and the turbine arrangement section 43 are arranged in series from the upstream side to the downstream side along the flow passage 4 in this order. However, as illustrated in FIG. 4, the flow passage 4 may have a path passing through the first heat exchange section 41 and a path passing through the second heat exchange section 42 in parallel. In the embodiment illustrated in FIG. 4, the flow passage 4, which branches into a path passing through the first heat exchange section 41 and a path passing through the second heat exchange section 42 on the upstream side, merges again, and the turbine arrangement section 43 is arranged downstream of the merged point. However, although not illustrated, the turbine arrangement section 43 may be arranged downstream of either the path passing through the first heat exchange section 41 or the path passing through the second heat exchange section 42 without such merging. In this case, the branched paths may join together on the downstream side of the other one and on the downstream side of the turbine arrangement section 43 .

[0047] In addition, although the embodiment in which the flow passage 4 branches and merges in the case 1 has been exemplified here, a configuration in which two inlets 11 and two outlets 12 are provided, and a path passing through the first heat exchange section 41 and a path passing through the second heat exchange section 42 are disposed independently of each other may be used. Also, a configuration in which one inlet 11 and two outlets 12 are provided, and the branched flow passages 4 are guided to the respective outlets 12 without merging may be used. Also, a configuration in which two inlets 11 and one outlet 12 are provided, and the coolant flowing in through independent paths merges into one path and flows out from one outlet 12 may be used.

[0048] [Overview of the embodiment] The above-described drive device (100) will now be briefly described.

[0049] In one embodiment, the drive device (100) includes a rotating electric machine (2), an inverter (INV) that drives the rotating electric machine (2), a case (1) that houses the rotating electric machine (2) and the inverter (INV), and an oil pump (8) that discharges oil to be supplied to the rotating electric machine (2), wherein the case (1) includes a flow passage (4) through which a coolant flows, and the flow passage (4) includes a first heat exchange section (41) in which heat exchange between the inverter (INV) and the coolant takes place, and a turbine arrangement section (43) in which a turbine (7) is arranged, and the turbine (7) rotates due to the flow of the coolant passing through the turbine arrangement section (43), and a pump rotor (88) of the oil pump (8) is drivingly connected to the turbine (7).

[0050] According to this configuration, the turbine (7) is rotated by the flow of the cooling liquid, and the rotation of the turbine (7) drives the pump rotor (88). This simplifies the configuration of the oil pump (8) compared to a configuration in which a separate drive source for the oil pump is provided, such as an electric oil pump. Furthermore, compared to a configuration in which the oil pump is driven by the driving force of the rotating electric machine (2), a power transmission mechanism between the rotating electric machine (2) and the oil pump (8) is not required, and loss of the driving force of the rotating electric machine (2) for driving the oil pump (8) can be avoided. Furthermore, since the inverter (INV) is likely to generate heat when power is supplied to the rotating electric machine (2), it is often necessary to cool the rotating electric machine (2) when the inverter (INV) needs to be cooled. According to this configuration, when the inverter (INV) is being cooled by the cooling liquid, the oil pump (8) can be driven by the cooling liquid to supply oil to the rotating electric machine (2) and cool the rotating electric machine (2). This allows both the inverter (INV) and the rotating electric machine (2) to be appropriately cooled at an appropriate time. Thus, according to this configuration, it is possible to supply oil to the rotating electric machine (2) at an appropriate time while suppressing increases in cost and size of the drive device (100).

[0051] In the drive device (100), it is preferable that at least one of the oil pump (8) and the turbine (7) is disposed inside the case (1).

[0052] For example, when the oil pump (8) is disposed inside the case (1), it is easier to shorten the oil passage (6) from the oil pump (8) to the rotating electrical machine (2) compared to a configuration in which the oil pump (8) is disposed outside the case (1). Also, when the turbine (7) is disposed inside the case (1), it is easier to shorten the flow passage compared to a configuration in which the turbine (7) is disposed outside the case (1).

[0053] Moreover, it is preferable that the case (1) of the driving device (100) includes a first accommodating portion (E1) that accommodates the rotating electric machine (2) and a second accommodating portion (E2) that accommodates the inverter (INV), and that the first accommodating portion (E1) and the second accommodating portion (E2) are integrally formed.

[0054] According to this configuration, it is easier to shorten the flow passage (4) compared to a configuration in which the first storage portion (E1) and the second storage portion (E2) are separate.

[0055] It is also preferable that the drive device (100) be arranged in the order of the first heat exchange section (41) and the turbine arrangement section (43) from upstream to downstream along the flow passage (4).

[0056] When the cooling liquid rotates the turbine (7), the flow rate of the cooling liquid decreases. Heat exchange is more effective when the flow rate of the cooling liquid is faster. According to this configuration, the first heat exchange section (41) is disposed upstream of the turbine arrangement section (43) in the flow passage (4). Therefore, cooling can be efficiently performed in the first heat exchange section (41) before the flow rate decreases due to the rotation of the turbine (7).

[0057] Moreover, it is preferable that the drive unit (100) further includes a second heat exchange section (42) in which heat exchange takes place between the oil stored in an oil storage section (P) provided in the case (1) and a coolant, and that the first heat exchange section, the second heat exchange section, and the turbine arrangement section are arranged in this order from the upstream side to the downstream side along the flow passage (4).

[0058] In addition to the first heat exchanger (41) that cools the inverter device (INV) by heat exchange with the inverter device (INV), the second heat exchanger (42) is further provided, so that the oil can be cooled by heat exchange with the oil stored in the oil storage section (P). In other words, both the oil in the case (1) and the inverter device (INV) can be cooled by the coolant. For example, the oil stored in the oil storage section (P) is pumped by the oil pump (8) to the rotating electric machine (2). The oil is supplied to the object to be cooled, such as the coil end portion (24e) of the oil coolant, thereby cooling the object to be cooled. By supplying the oil cooled by the coolant to the object to be cooled, not only the inverter device (INV) but also the object to be cooled can be effectively cooled. In addition, the first heat exchange section (41) and the second heat exchange section (42) are arranged upstream of the turbine arrangement section (43) in the flow passage (4). When the coolant rotates the turbine (7), the flow rate of the coolant decreases. In addition, heat exchange is performed more effectively when the flow rate of the coolant is faster. With this configuration, cooling can be efficiently performed in the first heat exchange section (41) and the second heat exchange section (42) before the flow rate decreases due to the rotation of the turbine (7). In addition, by passing the coolant through the first heat exchange section (41) before the second heat exchange section (42), the inverter device (INV) can be appropriately cooled by the coolant before its temperature increases by absorbing heat from the heated oil. In other words, the inverter unit (INV) can be cooled by the coolant with a higher cooling capacity. [Explanation of symbols]

[0059] 1: case, 2: rotating electric machine, 4: flow passage, 6: oil passage, 7: turbine, 8: oil pump, 11: inlet, 12: outlet, 21: rotor, 23: stator, 41: first heat exchange section, 42: second heat exchange section, 43: turbine arrangement section, 62a: oil supply port, 82: discharge port, 88: pump rotor, 100: drive unit, E1: first housing section, E2: second housing section, INV: inverter, P: oil storage section, Z: non-conductive member

Claims

1. A rotating electric machine; an inverter that drives the rotating electric machine; a transmission mechanism that transmits power between the rotating electric machine and a pair of wheels; a case that accommodates the rotating electric machine, the inverter, and the transmission mechanism; an oil pump that discharges oil to be supplied to the rotating electric machine; an oil reservoir formed in a bottom portion of the case; An oil reservoir disposed above the oil reservoir in the case, The transmission mechanism scoops up the oil stored in the oil reservoir, the oil reservoir stores oil scooped up from the oil reservoir by the transmission mechanism, the case has a flow passage through which a cooling liquid flows, the flow passage includes a first heat exchange section in which heat exchange occurs between the inverter and a coolant, a second heat exchange section in which heat exchange occurs between the oil stored in the oil storage section and the coolant, and a turbine arrangement section in which a turbine is arranged, the first heat exchange unit, the second heat exchange unit, and the turbine arrangement unit are disposed in this order from the upstream side to the downstream side along the flow passage, a drive unit, the turbine being rotated by a flow of coolant passing through the turbine arrangement, and a pump rotor of the oil pump being drivingly connected to the turbine;

2. The drive device according to claim 1 , wherein at least one of the oil pump and the turbine is disposed within the case.

3. the case includes a first housing portion that houses the rotating electric machine and a second housing portion that houses the inverter, The drive device according to claim 1 , wherein the first housing portion and the second housing portion are integrally formed.

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