Vehicular drive device

Abstract

A vehicular drive device (1) is configured so that the supply of oil from an oil pump (6) to a rotary electric machine (2) is cut off when a first control valve (VX) that switches a first supply path (71) for supplying oil to the rotary electric machine (2) between a communicated state and a cut-off state is closed, and the supply of oil from the oil pump (6) to a power transmission mechanism (3) is cut off when a second control valve (VY) that switches a second supply path (72) for supplying oil to the power transmission mechanism (3) between a communicated state and a cut-off state is closed.

Description

Vehicle drive device

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

[0002] In Japanese Patent Application Laid-Open No. 2024-40788, there is disclosed a vehicle drive device (1) including a rotary electric machine (2) that drives a wheel, a gear mechanism (3) that transmits power from the rotary electric machine (2) to the wheel, and a case (6) that houses the rotary electric machine (2) and the gear mechanism (3) (in the background art, the reference numerals in parentheses refer to those in the cited document). Inside the case (6), oil for lubricating (including cooling) the rotary electric machine (2) and the gear mechanism (3) is also housed. When the temperature of the oil in the case (6) is equal to or higher than the switching temperature, oil is supplied to the rotary electric machine (2) and the gear mechanism (3) (first state). On the other hand, when the temperature of the oil is lower than the switching temperature, oil is supplied to a part of the rotary electric machine (2) and the gear mechanism (3), or only to the gear mechanism (3) (second state). In addition, when the vehicle is stopped and the temperature of the oil is low and it is desired to raise the temperature of the oil, a mode in which oil is supplied only to the rotary electric machine (2) can also be selected (third state). That is, in this vehicle drive device (1), considering the temperature of the oil in the case (6), the supply of oil is controlled so as to reduce the load of the oil pump (8) that supplies oil and appropriately supply oil to the locations where oil is required.

[0003] Japanese Patent Application Laid-Open No. 2024-40788

[0004] In the above document, a form of switching the oil supply path by a thermostat valve or the cooperation of a temperature sensor and a control valve is exemplified. That is, it is shown that the oil supply form is switched solely according to the temperature of the oil. However, even when the temperature of the oil is high, when the vehicle is stopped and the gear mechanism is not rotating, or when the rotational speed of the rotary electric machine is low and the load of the rotary electric machine is small, there may be no need to supply oil to both the gear mechanism and the rotary electric machine. If the oil pump supplies unnecessary oil, energy is wasted accordingly. That is, there is still room for improvement in optimizing the workload of the oil pump that supplies oil to the oil circuit of the vehicle drive device.

[0005] In light of the above background, it is desirable to appropriately set the flow state of oil supplied from the oil pump to the oil circuit of the vehicle's drive system according to the operating state of the vehicle's drive system.

[0006] A vehicle drive system in view of the above comprises a rotating electric machine, an output member driven to a wheel, a power transmission mechanism for transmitting power between the rotating electric machine and the output member, a case containing oil, an oil pump for drawing in and discharging the oil, and an oil circuit through which the oil discharged from the oil pump circulates, wherein the oil circuit comprises a first supply path for supplying the oil discharged from the oil pump to the rotating electric machine, a second supply path for supplying the oil discharged from the oil pump to the power transmission mechanism, a first control valve for switching the first supply path between an open state and a closed state, and a second control valve for switching the second supply path between an open state and a closed state, wherein when the first control valve is closed, the supply of oil from the oil pump to the rotating electric machine is cut off, and when the second control valve is closed, the supply of oil from the oil pump to the power transmission mechanism is cut off.

[0007] With this configuration, for example, when the temperature of the rotating electric machine is sufficiently low and oil supply to the rotating electric machine is unnecessary, the first control valve can be shut off, thereby cutting off the supply of unnecessary oil to the rotating electric machine and reducing the load on the oil pump. Similarly, when the vehicle is stopped and the power transmission mechanism is not rotating, and oil supply to the power transmission mechanism is unnecessary, the second control valve can be shut off, thereby cutting off the supply of unnecessary oil to the power transmission mechanism and reducing the load on the oil pump. Therefore, it is possible to appropriately supply the necessary oil to both the rotating electric machine and the power transmission mechanism while suppressing the supply of unnecessary oil and reducing the load on the oil pump. In this way, with this configuration, the flow state of the oil supplied from the oil pump to the oil circuit of the vehicle drive system can be appropriately set according to the operating state of the vehicle drive system.

[0008] Further features and advantages of the vehicle drive system will become clear from the following description of exemplary and non-limiting embodiments, which will be illustrated with reference to the drawings.

[0009] System configuration diagram of a vehicle including a vehicle drive unit Diagram showing an example of a lubrication system for a vehicle drive unit Diagram showing an example of a lubrication system for a vehicle drive unit Flowchart showing an example of control of the lubrication system for a vehicle drive unit Diagram showing an example of the region controlling the first and second control valves Diagram showing an example of the region controlling the first and second control valves Diagram showing an example of the output of a motor pump Diagram showing an example of the output of a motor pump System configuration diagram of a vehicle including a vehicle drive unit Diagram showing an example of a lubrication system for a vehicle drive unit Flowchart showing an example of control of the lubrication system for a vehicle drive unit Skeleton diagram of a vehicle drive unit Control block diagram Schematic diagram of an oil circuit Schematic diagram of an oil circuit of a different embodiment A schematic diagram showing the oil circuit of an implementation. A schematic diagram showing the oil circuit of a different embodiment. Control flow diagram. Control flow diagram. Control flow diagram. Skeleton diagram of a vehicle drive transmission device. Control block diagram. A schematic diagram showing the oil circuit. A schematic side view showing the arrangement relationship between a fixed member and a movable member on the side. A schematic cross-sectional diagram showing the arrangement relationship between a fixed member and a movable member on the bottom. A schematic cross-sectional diagram showing the engagement state between a movable member and a fixed member. A schematic side view showing the arrangement relationship between a fixed member and a movable member on the side in a different embodiment. A schematic cross-sectional diagram showing the arrangement relationship between a fixed member and a movable member on the bottom in a different embodiment. A schematic cross-sectional diagram showing the engagement state between a movable member and a fixed member in a different embodiment. Control flow diagram.

[0010] [First Embodiment] Hereinafter, embodiments of the vehicle drive system will be described with reference to the drawings. As shown in Figure 1, the vehicle drive system 1 of this embodiment comprises a rotating electric machine 2, an output member 33 that is driven and connected to a wheel 4, and a power transmission mechanism 3 that transmits power between the rotating electric machine 2 and the output member 33. The vehicle drive system 1 also comprises a case 9 that houses the rotating electric machine 2 and the power transmission mechanism 3. The vehicle drive system 1 also comprises an oil circuit 7 that supplies cooling (including lubrication) oil to the rotating electric machine 2 and the power transmission mechanism 3. The oil circuit 7 comprises a first supply passage 71 and a second supply passage 72 as supply passages through which oil discharged from an oil pump 6 that sucks in and discharges oil stored in the case 9 circulates. The first supply passage 71 is a supply passage that supplies oil discharged from the oil pump 6 to the rotating electric machine 2. The second supply passage 72 is a supply passage that supplies oil discharged from the oil pump 6 to the power transmission mechanism 3. The first supply passage 71 is formed, for example, to pass from an internal case oil passage formed in the case 9 through an internal shaft oil passage that passes radially inside the rotor shaft 20, which will be described later. Also, if there is an oil chamber (coil oil chamber) covering the stator coil 24, which will be described later, the first supply passage 71 may be a path that supplies oil only to the coil oil chamber.

[0011] Furthermore, the vehicle drive unit 1 includes a first control valve VX that switches the first supply passage 71 between an open state and an open state, and a second control valve VY that switches the second supply passage 72 between an open state and an open state. In the following description, when the terms "cooling" and "lubrication" are used, unless otherwise specified, they both include the meanings of "cooling" and "lubrication". The oil pump 6 is preferably an electric oil pump driven by an electric motor. The discharge volume of the electric oil pump can be changed by changing the rotational speed of the pump rotor and the torque of the pump drive source.

[0012] Figure 1 illustrates the configuration of the rotating electric machine 2 and power transmission mechanism 3 that receive oil, but the configuration of the rotating electric machine 2 and power transmission mechanism 3 is not limited to this example. In the example shown in Figure 1, the rotating electric machine 2 is a traction motor that receives power from an on-board DC power supply (not shown) and serves as a driving force source for the wheels 4, and also functions as a generator that generates electricity from the power transmitted from the wheels 4, etc., and charges the DC power supply. In this embodiment, the rotating electric machine 2 is an inner rotor type rotating electric machine that comprises a rotor 21 and a stator 22 arranged radially outside the rotor 21. The stator coil 24 of the stator 22, the rotor shaft 20 that rotates integrally with the rotor 21, and the rotating members of the power transmission mechanism 3 and bearings (not shown) that rotatably support the rotor shaft 20 are the recipients of the oil.

[0013] In this embodiment, a vehicle drive system 1 with a three-axis configuration is illustrated, in which rotating members are arranged with the first axis A1, second axis A2, and third axis A3, which are parallel to each other and serve as rotation axes. The rotating electric machine 2 is arranged on the first axis A1. A reduction gear 31 that reduces the rotation of the rotor 21 of the rotating electric machine 2 is arranged on the second axis A2. In the illustrated example, the reduction gear 31 is a counter gear mechanism. A differential gear 32 that distributes the power transmitted from the rotor 21 via the reduction gear 31 to a pair of wheels 4 is arranged on the third axis A3. In the illustrated example, the differential gear 32 is a bevel gear type differential gear mechanism, and the side gears in the bevel gear mechanism, or the drive shaft 44 that connects the side gears to the wheels 4, or the connection part between the connecting shaft and the side gears, correspond to the output member 33. The reduction gear 31 and the differential gear 32 correspond to the power transmission mechanism 3.

[0014] As described above, the configuration of the power transmission mechanism 3 is not limited to the illustrated form. For example, the vehicle drive unit 1 may be a two-axis configuration (folded two-axis configuration) in which the differential 32 is arranged on the first axle A1. Alternatively, the vehicle drive unit 1 may be a two-axis configuration in which the reduction gear 31 is arranged coaxially with the rotor 21 by a planetary gear mechanism. Alternatively, the vehicle drive unit 1 may be a one-axis configuration in which the rotor 21, the reduction gear 31 of the planetary gear mechanism, and the differential 32 of a bevel gear mechanism or planetary gear mechanism are arranged coaxially. Alternatively, the vehicle drive unit 1 may be a four-axis or more configuration in which the reduction gear 31 is arranged on two or more axes. Alternatively, the vehicle drive unit 1 may not have a differential 32, and the power of the rotating electric machine 2 may be transmitted to one wheel 4. In this case, the output member 33 corresponds to the output shaft connected to the wheel 4, the final gear of the reduction gear 31, or the connection between the reduction gear 31 and the output shaft. Furthermore, the vehicle drive system 1 may include an internal combustion engine (not shown) that provides power to the rotating electric machine 2 when the rotating electric machine 2 functions as a generator. Regardless of the form of the power transmission mechanism 3, the power transmission mechanism 3 includes various transmission shafts and various gears. The power transmission mechanism 3 may also include engagement elements such as clutches and brakes.

[0015] As described above, the vehicle drive system 1 includes a first supply passage 71 for supplying oil to the rotating electric machine 2, a second supply passage 72 for supplying oil to the power transmission mechanism 3, a first control valve VX for switching the first supply passage 71 between an open state and an open state, and a second control valve VY for switching the second supply passage 72 between an open state and an open state. When the first control valve VX is in the closed state, the supply of oil from the oil pump 6 to the rotating electric machine 2 is cut off, and when the second control valve VY is in the closed state, the supply of oil from the oil pump 6 to the power transmission mechanism 3 is cut off. In other words, by closing either the first control valve VX or the second control valve VY, it is possible to cut off either the supply of oil to the entire rotating electric machine 2 or the supply of oil to the entire power transmission mechanism 3.

[0016] Furthermore, as is clear from the skeleton in Figure 1, the rotor 21 and the reduction gear 31 are driven and connected via gears, etc., so some of the power transmission members between the rotor 21 and the reduction gear 31 may be located in the rotating electric machine housing (for example, gears that are arranged on the first shaft A1 and mesh with the gears of the reduction gear 31). In other words, the core components of the power transmission mechanism 3 are housed in the power transmission mechanism housing, and some of the components are housed in the rotating electric machine housing. Even if the supply of oil to the entire rotating electric machine 2 is cut off, when oil is supplied to the power transmission mechanism 3, it is not excluded that oil will be supplied to rotating members such as gears that mesh with the gears of the reduction gear 31 and bearings of the rotor shaft 20. "The entire rotating electric machine 2" preferably refers to "the core components of the rotating electric machine 2 (for example, stator coil 24, stator core, rotor core)".

[0017] For example, when the temperature of the rotating electric machine 2 is sufficiently low, and oil supply to the rotating electric machine 2 is unnecessary, the first control valve VX can be shut off to cut off the supply of unnecessary oil to the rotating electric machine 2, thereby reducing the load on the oil pump 6. Also, when the vehicle is stopped and the power transmission mechanism 3 is not rotating, and oil supply to the power transmission mechanism 3 is unnecessary, the second control valve VY can be shut off to cut off the supply of unnecessary oil to the power transmission mechanism 3, thereby reducing the load on the oil pump 6. In other words, the necessary oil supply to the rotating electric machine 2 and the power transmission mechanism 3 can be appropriately maintained while suppressing the supply of unnecessary oil, thereby reducing the load on the oil pump 6.

[0018] Figures 2 and 3 show an example of the lubrication system of the vehicle drive unit 1. Figure 2 is an example where the first control valve VX is controlled to be in communication and the second control valve VY is controlled to be closed, and Figure 3 is an example where the first control valve VX is controlled to be closed and the second control valve VY is controlled to be in communication. Solid lines show the paths through which oil flows, and dashed lines show the paths through which oil flow is blocked. In reality, even when each valve is in the closed state, oil reaches the upstream side of each valve, but the figures are illustrated with visibility in mind so that it is easy to understand whether the first supply passage 71 and the second supply passage 72 are functioning as a whole.

[0019] As shown in Figures 2 and 3, the first supply passage 71 is a circulation path through which oil is drawn in by the oil pump 6 from the oil reservoir P in the case 9 and discharged, returning to the oil reservoir P via the oil cooler 8, the first control valve VX, and the rotating electric machine 2. The second supply passage 72 is a circulation path through which oil is drawn in by the oil pump 6, for example from the bottom of the case 9, and discharged, returning to the bottom of the case 9 via the oil cooler 8, the second control valve VY, and the power transmission mechanism 3. The oil cooler 8 is a heat exchanger that performs heat exchange between oil and a heat transfer medium 80 (such as cooling water like LLC (Long Life Coolant) or refrigerant for an air conditioner). The oil cooler 8 and the oil pump 6 may be located outside the case 9, and therefore, parts of the first supply passage 71 and the second supply passage 72 may pass outside the case 9.

[0020] Figures 2 and 3 illustrate an example in which the first supply passage 71 and the second supply passage 72 merge downstream of the oil storage section P and are connected to the oil pump 6. However, the oil storage section P may be used in common by both the first supply passage 71 and the second supply passage 72. That is, the first supply passage 71 and the second supply passage 72 may merge upstream of the oil storage section P and be connected to the oil pump 6. For example, the case 9 may include a rotating electric machine housing chamber and a power transmission mechanism housing chamber separated from each other by partition walls or partition members. The oil storage section P may be formed in the rotating electric machine housing chamber and the oil in the power transmission mechanism housing chamber may merge into the oil storage section P, or the oil storage section P may be formed in the power transmission mechanism housing chamber and the oil in the rotating electric machine housing chamber may merge into the oil storage section P. Naturally, oil reservoirs may be formed in both the rotating electric machine housing and the power transmission mechanism housing, and the oil may merge downstream of these oil reservoirs.

[0021] As shown in Figure 2, when the first control valve VX is controlled to be in communication and the second control valve VY is controlled to be in a closed state, oil does not circulate in the second supply passage 72, and the oil circulates in the first supply passage 71. As shown in Figure 3, when the first control valve VX is controlled to be in a closed state and the second control valve VY is controlled to be in communication, oil does not circulate in the first supply passage 71, and the oil circulates in the second supply passage 72. Although not shown in the figure, when the first control valve VX and the second control valve VY are controlled to be in communication, the oil circulates in both the first supply passage 71 and the second supply passage 72. Naturally, when the first control valve VX and the second control valve VY are controlled to be in a closed state, the oil does not flow in either the first supply passage 71 or the second supply passage 72. Therefore, in this case, it is preferable to stop the oil pump 6 as well. Furthermore, it is preferable that the discharge volume of the oil pump 6 is controlled along with the control of the first control valve VX and the second control valve VY.

[0022] The procedure for controlling the first control valve VX and the second control valve VY will be described below, with reference to the flowchart in Figure 4. The first control valve VX and the second control valve VY are controlled by the control unit 5, as shown in Figure 1. The oil pump 6, the rotating electric machine 2, etc., are also controlled by the control unit 5.

[0023] The control unit 5 first receives various vehicle signals such as a temperature sensor (not shown) for detecting the oil temperature, a temperature sensor (not shown) for detecting the temperature of the rotating electric machine 2 (stator coil 24, stator core, rotor core, permanent magnet), a temperature sensor (not shown) for detecting the temperature inside the vehicle, a temperature sensor (not shown) for detecting the temperature of the onboard DC power supply, a rotation sensor (not shown) for detecting the rotational speed of the rotating electric machine 2, a rotation sensor 55 for detecting the rotational speed of the wheels 4 or output members 33, the torque required for the vehicle drive system 1, and the set temperature of the air conditioner (#10).

[0024] For example, in cold weather, when a vehicle is started after being stopped for a long time, a heat source is needed for the air conditioner to raise the temperature inside the vehicle. In conventional vehicles that use an internal combustion engine as the driving force for the wheels 4, the waste heat from the internal combustion engine can be used for heating. However, in electric vehicles that use a rotating electric machine 2 as the driving force for the wheels 4, such waste heat cannot be used. Also, even in hybrid vehicles, the use of such waste heat is limited. Furthermore, the DC power supply that provides power to the rotating electric machine 2 tends to degrade in performance at low temperatures, and it is sometimes preferable to warm it up (warm-up). Therefore, when such heat is needed, the control unit 5 selects the "stationary heat generation mode" as the control mode for the first control valve VX and the second control valve VY (#21). In the stationary heat generation mode, the control unit 5 controls the second control valve VY to the shut-off state (#31) and the first control valve VX to the connected state (#41). As a result, the oil does not circulate through the second supply passage 72 of the oil circuit 7, but circulates through the first supply passage 71, as shown in Figure 2. The oil pump 6 is controlled according to the condition "$1", as will be described later.

[0025] The control unit 5 drives the rotating electric machine 2 in an inefficient mode, supplying electricity to the stator coil 24 in such a way that it does not generate torque (so that the rotor 21 does not rotate), thereby generating heat in the stator coil 24. The oil that has exchanged heat with the stator coil 24 is then exchanged with a heat transfer medium 80 such as a coolant in the oil cooler 8 and used in an air conditioner or the like. Considering that the oil flowing through the first supply passage 71 is used in this "stationary heat generation mode," the first supply passage 71 may be a low heat dissipation path with higher heat retention than the second supply passage 72. For example, if the oil is in direct contact with the case 9, the oil will dissipate heat more easily through the case 9, so at least a part of the first supply passage 71, such as the oil passage or a part of the oil reservoir P, may be made of resin.

[0026] Even after the vehicle has started moving, heat may be needed for heating the cabin or for warming up the engine. In this case, the control unit 5 selects the "waste heat recovery mode" (#22). Since the power transmission mechanism 3 is also rotating, in waste heat recovery mode, the control unit 5 controls the second control valve VY to be in communication mode (#32) and also controls the first control valve VX to be in communication mode (#42). As a result, the oil circulates through both the first supply passage 71 and the second supply passage 72 of the oil circuit 7. The heat generated by the rotating electric machine 2 and the power transmission mechanism 3 is recovered in the oil and used after heat exchange with the heat transfer medium 80 in the oil cooler 8. The oil pump 6 is controlled according to the condition "$2", as will be described later.

[0027] The "stationary heat generation mode" and the "waste heat recovery mode" can be described as "heat utilization modes" that cause the oil pump 6, the first control valve VX, and the second control valve VY to perform operations to utilize the heat of the heat transfer medium 80 in the vehicle. The control unit 5 includes, as "heat utilization modes," a "stationary heat generation mode" that is executed when the vehicle is not running, and a "waste heat recovery mode" that is executed when the vehicle is running.

[0028] When not in "heat utilization mode," the control unit 5 controls the oil pump 6, the first control valve VX, and the second control valve VY in "general mode." "General mode" is a control mode used when the purpose is not to actively utilize the heat of the oil, but to cool and lubricate the vehicle drive system 1 with oil. In general mode, the control unit 5 determines the control mode of the oil pump 6, the first control valve VX, and the second control valve VY based on control regions (first region AX, second region BX) set based on the temperature of the rotating electric machine 2 (motor temperature Tmg) and the load of the rotating electric machine 2 (motor load ratio LFmg), as illustrated in Figures 5 and 6. The first region AX is a control region where the motor temperature Tmg is less than the temperature threshold Tt and the motor load ratio LFmg is less than the load threshold Tlf. The second region BX is a control region where the motor temperature Tmg is greater than or equal to the temperature threshold Tt and the motor load ratio LFmg is greater than or equal to the load threshold Tlf.

[0029] The control range varies depending on the oil temperature (oil temperature Toil). Figure 6 shows an example where the oil temperature Toil is above the oil temperature threshold Tn (see Figure 8), while Figure 5 shows an example where the oil temperature Toil is between the first temperature and the second temperature. Note that both the first and second temperatures are below the oil temperature threshold Tn. The oil temperature threshold Tn is an indicator value that indicates that the amount of heat the oil can absorb decreases, resulting in reduced cooling performance. "Tres" is the "load factor limiting start temperature," which is an indicator value that indicates that the temperature of the rotating electric machine 2 is high and the load factor of the rotating electric machine 2 is limited.

[0030] In general mode, when the vehicle is running (No. 21), and the motor temperature Tmg, which is the temperature of the rotating electric machine 2, is less than the temperature threshold Tt, and the motor load ratio LFmg, which is the load of the rotating electric machine 2, is less than the load threshold Tlf, the control unit 5 opens the second control valve VY and closes the first control valve VX (No. 23, 33, 43). The oil pump 6 is controlled according to the condition "$3", as will be described later.

[0031] In general mode, when the vehicle is running (No. 21), and the motor temperature Tmg is greater than or equal to the temperature threshold Tt, or the motor load factor LFmg is greater than or equal to the load threshold Tlf, the control unit 5 opens the second control valve VY and also opens the first control valve VX (No. 34, 44), or closes the second control valve VY and opens the first control valve VX (No. 35, 45). In this case, the first control valve VX and the second control valve VY are also controlled according to the vehicle speed (≒ rotational speed of the rotating electric machine 2 (MG rotation)). In the second region BX, when the vehicle speed is greater than or equal to the vehicle speed threshold x, the control unit 5 opens the second control valve VY and also opens the first control valve VX (No. 24, 34, 44). The oil pump 6 is controlled according to condition "$4", as described later. In addition, in the second region BX, the control unit 5 closes the second control valve VY and opens the first control valve VX when the vehicle speed is less than the vehicle speed threshold x (#24, #35, #45). The oil pump 6 is controlled according to condition "$5", as described later.

[0032] Furthermore, in general mode, when the second region BX is selected, the control unit 5 may control both the first control valve VX and the second control valve VY to be in communication state without the first control valve VX and the second control valve VY being controlled according to the vehicle speed (≒MG rotation).

[0033] The vehicle speed, which is the determination condition in step #24, may also be zero. In this case, the power transmission mechanism 3 does not rotate, and even in general mode, the vehicle may not be in a state of movement. When the vehicle speed is zero, it is preferable that the first control valve VX and the second control valve VY are controlled to be in the same state. In general mode, since the use of oil heat is not required, for example, both the first control valve VX and the second control valve VY are controlled to be in a shut-off state. Also, by reducing the discharge amount of the oil pump 6, for example to zero, the flow of oil in the oil circuit 7 can be stopped. Therefore, the control unit 5 may control both the first control valve VX and the second control valve VY to be in a connected state.

[0034] Furthermore, if the motor temperature Tmg is high and it is preferable to continue cooling the rotating electric machine 2 even when the vehicle speed is zero, the first control valve VX and the second control valve VY may be controlled to be in communication, and the oil pump 6 may be driven with a discharge rate based on the motor temperature Tmg and the oil temperature Toil.

[0035] Naturally, even when the vehicle speed is zero, the control unit 5 may control the second control valve VY to the closed state and the first control valve VX to the open state, similar to the flow from step #24 to step #35 and step #45 to "$5". In this case, if the motor temperature Tmg is high, the oil pump 6 should be driven with a discharge rate based on the motor temperature Tmg and the oil temperature Toil.

[0036] Furthermore, if the motor temperature Tmg is low, there is little need to continue cooling the rotating electric machine 2. Since there is no need to circulate oil in the oil circuit 7, the oil pump 6 may be stopped. Because the oil pump 6 is stopped, the first control valve VX and the second control valve VY may be controlled to either a closed state or a connected state.

[0037] Furthermore, hysteresis is provided in the transition between the first region AX and the second region BX. In Figures 5 and 6, the boundary between the first region AX and the second region BX is the A2B boundary line Lab, shown as a solid line, when transitioning from the first region AX to the second region BX, and the boundary between the second region BX and the first region AX is the B2A boundary line Lba, shown as a dashed line.

[0038] In the heat utilization mode, it is preferable to increase the flow rate of oil in the oil circuit 7 in order to effectively utilize the heat of the oil. For this reason, as shown in Figure 7, it is preferable that the oil pump 6 is driven with a high discharge force Hi and has a high discharge volume throughout the entire operating range defined by the oil temperature Toil and the motor temperature Tmg. That is, when the first control valve VX and the second control valve VY are controlled under the conditions of "$1" and "$2" shown in the flowchart of Figure 4, i.e., in the "heat utilization mode", the control unit 5 drives the oil pump 6 with a high discharge volume regardless of the oil temperature Toil and the motor temperature Tmg, as shown in Figure 7.

[0039] When the first control valve VX and the second control valve VY are controlled under the conditions "$3", "$4", and "$5" shown in the flowchart of Figure 4, i.e., in "general mode", the control unit 5 increases the amount of oil discharged by the oil pump 6 in accordance with the increase in oil temperature Toil and motor temperature Tmg, based on at least the oil temperature Toil and motor temperature Tmg. For example, as shown in Figure 8, the control unit 5 drives the oil pump 6 with different discharge forces in stages according to the oil temperature Toil and motor temperature Tmg. Generally, in the first region AX, the oil pump 6 is driven with at least three types of discharge forces: high discharge force Hi, medium discharge force Mid, and low discharge force Lo. In the second region BX, the oil pump 6 is driven with at least two types of discharge forces: high discharge force Hi and medium discharge force Mid. Naturally, high discharge force (Hi), medium discharge force (Mid), and low discharge force (Lo) may each be further divided into multiple discharge force levels.

[0040] In this embodiment, as shown in Figure 8, the control unit 5 is shown to drive the oil pump 6 with progressively different discharge forces according to the oil temperature Toil and the motor temperature Tmg. However, the control unit 5 may also drive the oil pump 6 with continuously different discharge forces according to the oil temperature Toil and the motor temperature Tmg. Furthermore, in this embodiment, the amount of oil discharged by the oil pump 6 is shown to be controlled based on the oil temperature Toil and the motor temperature Tmg. However, conditions other than the oil temperature Toil and the motor temperature Tmg, such as the load factor of the rotating electric machine 2, may also be used to control the discharge amount.

[0041] [Outline of the First Embodiment] The vehicle drive system (1) described above will be briefly summarized below.

[0042] In one embodiment, the vehicle drive system (1) comprises a rotating electric machine (2), an output member (33) driven and connected to a wheel (4), a power transmission mechanism (3) that transmits power between the rotating electric machine (2) and the output member (33), the rotating electric machine (2), the power transmission mechanism (3), and a case (9) containing oil, an oil pump (6) that sucks in and discharges the oil, and an oil circuit (7) through which the oil discharged from the oil pump (6) circulates, the oil circuit (7) having a first supply path that supplies the oil discharged from the oil pump (6) to the rotating electric machine (2) The device comprises (71), a second supply passage (72) for supplying the oil discharged from the oil pump (6) to the power transmission mechanism (3), a first control valve (VX) for switching the first supply passage (71) between an open state and an open state, and a second control valve (VY) for switching the second supply passage (72) between an open state and an open state. When the first control valve (VX) is in the open state, the supply of oil from the oil pump (6) to the rotating electric machine (2) is cut off, and when the second control valve (VY) is in the open state, the supply of oil from the oil pump (6) to the power transmission mechanism (3) is cut off.

[0043] With this configuration, for example, when the temperature of the rotating electric machine (2) is sufficiently low, and oil supply to the rotating electric machine (2) is unnecessary, the first control valve (VX) can be shut off, thereby cutting off the supply of unnecessary oil to the rotating electric machine (2) and reducing the load on the oil pump (6). Also, for example, when the vehicle is stopped and the power transmission mechanism (3) is not rotating, and oil supply to the power transmission mechanism (3) is unnecessary, the second control valve (VY) can be shut off, thereby cutting off the supply of unnecessary oil to the power transmission mechanism (3) and reducing the load on the oil pump (6). Therefore, the necessary oil supply to the rotating electric machine (2) and the power transmission mechanism (3) can be appropriately maintained while suppressing the supply of unnecessary oil and reducing the load on the oil pump (6).

[0044] Further, the vehicle drive device (1) includes a control unit (5) that controls the oil pump (6), the first control valve (VX), and the second control valve (VY). The oil circuit (7) includes a heat exchanger (8) that exchanges heat between the oil and the heat medium. The control unit (5) causes the oil pump (6), the first control valve (VX), and the second control valve (VY) to perform an operation for using the heat of the heat medium in the vehicle, and a general mode other than the heat utilization mode. In the general mode, when the vehicle is running, the temperature of the rotating electric machine (2) is less than a preset temperature threshold (Tt), and the load of the rotating electric machine (2) is less than a preset load threshold (Tl f), the first control valve (VX) is set to a cutoff state, and the second control valve (VY) is set to a communicating state. In the general mode, when the vehicle is running, and the temperature of the rotating electric machine (2) is equal to or higher than the temperature threshold (Tt), or the load of the rotating electric machine (2) is equal to or higher than the load threshold (Tl f), it is preferable that both the first control valve (VX) and the second control valve (VY) are set to a communicating state.

[0045] According to this configuration, when there is little need to use the heat of the heat medium in the vehicle, it is possible to switch whether or not to supply oil to the rotating electric machine (2) according to the necessity of cooling the rotating electric machine (2). Therefore, it is possible to cut off the wasteful supply of oil to the rotating electric machine (2) and reduce the load on the oil pump (6).

[0046] Further, in the vehicle drive device (1), in the general mode, based on the temperature of the oil and the temperature of the rotating electric machine (2), the control unit (5) increases the discharge amount of the oil by the oil pump (VY) as the temperature of the oil increases, and increases the discharge amount of the oil by the oil pump (6) as the temperature of the rotating electric machine (2) increases, which is preferable. [[ID=,8]]

[0047] According to this configuration, in the general mode, the operating state of the oil pump (6) can be appropriately changed according to the temperatures of the oil and the rotating electric machine (2). Therefore, it is easy to reduce the energy consumption by the oil pump (6).

[0048] Further, the vehicle drive device (1) includes a control unit (5) that controls the oil pump (6), the first control valve (VX), and the second control valve (VY). The oil circuit (7) includes a heat exchanger (8) that exchanges heat between the oil and the heat medium. The control unit (5) executes a heat utilization mode in which it causes the oil pump (6), the first control valve (VX), and the second control valve (VY) to perform operations for utilizing the heat of the heat medium in the vehicle, and a general mode other than the heat utilization mode. The control unit (5) includes a stop heat generation mode that is executed when the vehicle is not running and an exhaust heat recovery mode that is executed when the vehicle is running as the heat utilization mode. In the stop heat generation mode, the control unit (5) sets the first control valve (VX) to a communicating state and the second control valve (VY) to a blocking state. In the exhaust heat recovery mode, it is preferable that both the first control valve (VX) and the second control valve (VY) are set to a communicating state.

[0049] According to this configuration, when utilizing the heat of the heat medium in the vehicle, depending on whether the vehicle is running or not, the heat generated in the vehicle drive device (1) by driving the vehicle or the heat generated in the vehicle drive device (1) even when the vehicle is not running can be provided to the heat medium via the oil and the heat exchanger (8), and the oil can be appropriately supplied to the heat generation location in a targeted manner. Therefore, while reducing the load on the oil pump (6), the heat generated by the vehicle drive device (1) can be appropriately utilized.

[0050] [Second Embodiment] Japanese Patent Publication No. 2024-40788 discloses a vehicle drive system (1) comprising a rotating electric machine (2) for driving wheels, a gear mechanism (3) for transmitting power from the rotating electric machine (2) to the wheels, and a mechanism for supplying oil for lubrication (including cooling) to the rotating electric machine (2) and the gear mechanism (3) (in the background art, the reference numerals in parentheses refer to the referenced document). The housing space (80) of the case (6) housing the rotating electric machine (2) and the gear mechanism (3) is divided into a rotating electric machine housing chamber (81), a gear housing chamber (82), and an oil storage chamber (85) for storing oil. A first oil reservoir (P1) for storing oil that lubricates the gear mechanism (3) is provided in the lower region of the gear housing chamber (82), and a second oil reservoir (P2) for storing oil that lubricates (cools) the rotating electric machine (2) is provided in the lower region of the rotating electric machine housing chamber (81). The first oil reservoir (P1) and the second oil reservoir (P2) are connected by a partition wall opening (68) provided in the partition wall section (60b) that separates the rotating electric machine housing chamber (81) and the gear housing chamber (82), and oil moves from the second oil reservoir (P2) to the first oil reservoir (P1) via the partition wall opening (68). The first oil reservoir (P1) and the oil storage chamber (85) are connected by a connecting passage (92c), and a portion of the oil in the first oil reservoir (P1) is supplied to the oil storage chamber (85). The oil in the oil storage chamber (85) is drawn in and discharged by a pump (96) and supplied to the rotating electric machine (2) via a cooler (97). The cooler (97) performs heat exchange between the oil and the first refrigerant (R). The first refrigerant (R) further undergoes heat exchange with the outside air or other refrigerants (second refrigerant (R2)) in the radiator (126) and chiller (125).

[0051] The heat generated in a vehicle's drive system is not only released into the outside air via a radiator, but can also be utilized in heat exchangers such as chillers, as exemplified above (waste heat utilization). When considering such waste heat utilization, it is desirable that the heat generated in the vehicle's drive system be efficiently transferred to its intended use. In the above-mentioned vehicle drive system, the oil that lubricates the rotating electric machinery and the oil that lubricates the gear mechanism are always mixed together. For example, if the overall oil temperature of the vehicle's drive system is low, it takes time for the oil temperature to rise due to the heat from heat sources such as the rotating electric machinery, making it difficult to improve the efficiency of waste heat utilization.

[0052] Therefore, there is a need for technology that can properly cool and lubricate vehicle drive systems using oil, while also enabling the utilization of waste heat via oil with higher efficiency.

[0053] Hereinafter, embodiments of the vehicle drive system in view of the above will be described with reference to the drawings. As shown in Figure 9, the vehicle drive system 101 of this embodiment includes a rotating electric machine 102, an output member 133 that is driven and connected to a wheel 104, and a power transmission mechanism 103 that transmits power between the rotating electric machine 102 and the output member 133. As shown in Figure 10 and other figures, the vehicle drive system 101 includes a case 109 that houses the rotating electric machine 102 and the power transmission mechanism 103. Furthermore, as shown in Figures 9 and 10 and other figures, the vehicle drive system 101 includes an oil supply mechanism 170 that supplies cooling (including lubrication) oil to the rotating electric machine 102 and the power transmission mechanism 103. As will be described in detail later, the oil supply mechanism 170 includes a first circulation path 171 and a second circulation path 172 as oil passages 107 through which oil flows. Furthermore, the oil supply mechanism 170 is equipped with a valve V as a switching device for switching paths, and selectively switches between the first circulation path 171 and the second circulation path 172 as the paths through which the oil flows.In the following description, when the terms "cooling" and "lubrication" are used, unless otherwise specified, they both include the meanings of "cooling" and "lubrication".

[0054] Figure 9 illustrates the configuration of the rotating electric machine 102 and the power transmission mechanism 103, which are the recipients of the oil supply, but the configuration of the rotating electric machine 102 and the power transmission mechanism 103 is not limited to this example. In the example shown in Figure 9, the rotating electric machine 102 is a traction motor that is supplied with power from an on-board DC power supply 108 (see Figure 10) and serves as the driving force source for the wheels 104, and also functions as a generator that generates electricity from the power transmitted from the wheels 104, etc., and charges the DC power supply 108. In this embodiment, the rotating electric machine 102 is an inner rotor type rotating electric machine that comprises a rotor 121 and a stator 122 arranged radially outside the rotor 121. The stator coil 124 of the stator 122, the rotor shaft 120 that rotates integrally with the rotor 121, and the rotating members of the power transmission mechanism 103 and bearings (not shown) that rotatably support the rotor shaft 120 are the recipients of the oil supply.

[0055] In this embodiment, a vehicle drive system 101 with a three-axis configuration is illustrated, in which rotating members are arranged with the first axis A1, second axis A2, and third axis A3, which are parallel to each other and serve as rotation axes. The rotating electric machine 102 is located on the first axis A1. A reduction gear 131 is located on the second axis A2 to reduce the rotation of the rotor 121 of the rotating electric machine 102. In the illustrated example, the reduction gear 131 is a counter gear mechanism. A differential gear 132 is located on the third axis A3 to distribute the power transmitted from the rotor 121 via the reduction gear 131 to a pair of wheels 104. In the illustrated example, the differential gear 132 is a bevel gear type differential gear mechanism, and the side gears in the bevel gear mechanism, or the drive shaft 144 connecting the side gears to the wheels 104, or the connection between the connecting shaft and the side gears, correspond to the output member 133. The reduction gear 131 and the differential gear 132 correspond to the power transmission mechanism 103.

[0056] As described above, the configuration of the power transmission mechanism 103 is not limited to the illustrated form. For example, the vehicle drive system 101 may be a two-axis configuration (folded two-axis configuration) in which the differential 132 is arranged on the first axle A1. Alternatively, the vehicle drive system 101 may be a two-axis configuration in which the reduction gear 131 is composed of a planetary gear mechanism arranged coaxially with the rotor 121. Alternatively, the vehicle drive system 101 may be a one-axis configuration in which the rotor 121, the reduction gear 131 of the planetary gear mechanism, and the differential 132 of a bevel gear mechanism or planetary gear mechanism are arranged coaxially. Alternatively, the vehicle drive system 101 may be a four-axis or more configuration in which the reduction gear 131 is arranged on two or more axes. Alternatively, the vehicle drive system 101 may not have a differential 132, and the power of the rotating electric machine 102 may be transmitted to one wheel 104. In this case, the output member 133 corresponds to the output shaft connected to the wheel 104, the final gear of the reduction gear 131, or the connection between the reduction gear 131 and the output shaft. The vehicle drive system 101 may also include an internal combustion engine (not shown) that powers the rotating electric machine 102 when the rotating electric machine 102 functions as a generator. Regardless of the form of the power transmission mechanism 103, the power transmission mechanism 103 includes various transmission shafts and various gears. The power transmission mechanism 103 may also include engagement elements such as clutches and brakes.

[0057] The rotating electric machine 102 and the power transmission mechanism 103 may be housed in the same housing chamber within the case 109. However, in this embodiment, as shown in Figure 10 and other figures, the case 109 comprises a first housing chamber 191 and a second housing chamber 192, which are separated from each other by partition walls or partition members. The rotating electric machine 102 is housed in the first housing chamber 191, and the power transmission mechanism 103 is housed in the second housing chamber 192. As is clear from the skeleton in Figure 9, the rotor 121 and the reduction gear 131 are driven and connected via gears, etc., so a part of the power transmission member between the rotor 121 and the reduction gear 131 may be located within the first housing chamber 191 (for example, a gear arranged on the first shaft A1 that meshes with the gear of the reduction gear 131). In other words, the core components of the power transmission mechanism 103 can be housed in the second housing chamber 192, while a part of it is housed in the first housing chamber 191. As shown in Figure 10, the case 109 may also include a third housing chamber 193 that houses a rotating electric machine drive unit 180 for driving the rotating electric machine 102. The third housing chamber 193 is also separated from the first housing chamber 191 and the second housing chamber 192 by partition walls or partition members.

[0058] As shown in Figure 10, the rotating electric machine 102 is electrically connected to a DC power supply 108, which is composed of a secondary battery such as a lithium-ion battery or an energy storage device such as an electric double-layer capacitor, via a rotating electric machine drive unit 180. Here, a lithium-ion battery, which is composed of multiple battery cells integrated together, is used as an example of the DC power supply 108. The rotating electric machine drive unit 180 is equipped with an inverter 182 that converts power between the DC from the DC power supply 108 and the multi-phase (in this case, three-phase) AC from the rotating electric machine 102. The inverter 182 is composed of switching elements such as IGBTs (Insulated Gate Bipolar Transistors) and power MOSFETs (Metal Oxide Semiconductor Field Effect Transistors). The inverter 182 is configured, for example, as an inverter module in which multiple switching elements are mounted on a substrate. In addition, a smoothing capacitor 181 is provided on the DC side of the inverter 182.

[0059] The inverter 182 is switched-controlled by a rotating electric machine control device (not shown) based on the target torque of the rotating electric machine 102, which is set according to a command from a vehicle control device (not shown). Although not shown in Figure 10, it is preferable that the rotating electric machine control device is also housed in the third housing chamber 193. The rotating electric machine control device drives and controls the rotating electric machine 102 via the inverter 182 using, for example, a known vector control method, based on the detection results of a current sensor 183 that detects the current flowing through the busbar connecting the inverter 182 and the stator coil 124 of the rotating electric machine 102, and a rotation sensor (not shown) such as a resolver or inductive position sensor that detects the rotation of the rotor 121 (such as rotational speed and rotational position).

[0060] As shown in Figure 10, the vehicle drive unit 101 is configured to store oil in an oil reservoir 179 within the case 109. In Figure 10, for simplification, the oil reservoir 179 is shown as being provided separately from the first and second storage chambers 191 and 192, but the oil reservoir 179 is provided at least within the second storage chamber 192, at the bottom of the second storage chamber 192. Alternatively, the oil reservoir 179 may be provided spanning both the first and second storage chambers 191 and 192. Or, the oil reservoir 179 may be provided at the bottom of the second storage chamber 192, and a second oil reservoir may also be provided at the bottom of the first storage chamber 191, with the second oil reservoir and the oil reservoir 179 in communication. Naturally, the oil storage section 179 may be located in a separate space within the case 109, partitioned from the first storage chamber 191 and the second storage chamber 192.

[0061] The vehicle drive unit 101 further includes an oil pump 161 and an oil cooler 162 (heat exchanger). The oil pump 161 is a pump that can be operated by another power source even when the vehicle drive unit 101 is stopped, for example, an electric oil pump. Figure 10 illustrates a configuration in which the oil pump 161 is housed inside a case 109 and the oil cooler 162 is located outside the case 109. The oil cooler 162 is mounted, for example, on the side of the case 109. The configuration is not limited to this, and the oil pump 161 and oil cooler 162 may be located outside the case 109 and mounted on the side of the case 109. Of course, the oil pump 161 and oil cooler 162 may also be housed inside the case 109.

[0062] The vehicle drive unit 101 is equipped with an oil passage 107 through which oil discharged from the oil pump 161 flows. The oil passage 107 includes both closed oil passages such as a passage formed inside the stator cover 125 (cover internal oil passage 173) and a passage inside the rotor shaft 120, as well as a passage through which oil that has lubricated the gears and bearings drips (open oil passage).

[0063] The oil cooler 162 is a heat exchanger that performs heat exchange between the oil flowing through the oil passage 107 and a heat transfer medium (e.g., cooling water). In this embodiment, the oil cooler 162 is shown positioned downstream of the oil passage 107 relative to the oil pump 161. However, the oil cooler 162 may also be positioned upstream of the oil passage 107 relative to the oil pump 161.

[0064] In this embodiment, the oil flow path 107 includes a first circulation path 171 and a second circulation path 172. The first circulation path 171 and the second circulation path 172 may be independent oil flow paths without overlap, or they may overlap in part and share some flow paths. Furthermore, the first circulation path 171 and the second circulation path 172 may have branching or merging sections along their paths. In this embodiment, the first circulation path 171 includes the entirety of the second circulation path 172.

[0065] The first circulation path 171 is an oil passage 107 through which oil circulates, passing through the oil pump 161, the oil cooler 162, the rotating electric machine 102, and the parts of the power transmission mechanism 103 that require lubrication. The parts of the power transmission mechanism 103 that require lubrication are, as described above, the gear meshing parts, bearings, engagement devices, etc. The second circulation path 172 is an oil passage 107 through which oil circulates, passing through the oil pump 161, the oil cooler 162, and the rotating electric machine 102 without passing through the parts of the power transmission mechanism 103 that require lubrication. The second circulation path 172 may include oil passages formed in a part of the power transmission mechanism 103 (for example, a shaft member) if it does not supply oil to the parts of the power transmission mechanism 103 that are to be lubricated as described above, and simply passes through (even if heat exchange occurs, it is limited and not actively heat exchange).

[0066] The oil passage 107 is equipped with a valve V, which serves as a switching device for switching the path through which the oil flows. In this embodiment, the valve V consists of a first valve V1 and a second valve V2. In this embodiment, the first valve V1 and the second valve V2 are electromagnetically controlled valves. The first valve V1 selectively switches between the first circulation path 171 and the second circulation path 172 as the path through which the oil flows. The second valve V2 switches whether or not to circulate oil in the oil passage 107 between the oil reservoir 179 and the oil pump 161. As will be described later, the first valve V1 and the second valve V2 are opened and closed by control of the control device 105.

[0067] The first circulation path 171 is formed when both the first valve V1 and the second valve V2 are controlled to be in the open state. Since the second valve V2 is in the open state, the oil pump 161 sucks in oil from the oil reservoir 179 and discharges it. Since the first valve V1 is in the open state, the oil discharged from the oil pump 161 passes through the oil passage 107 and is supplied to the oil passage formed inside the rotor shaft 120 of the rotating electric machine 102, the stator coil 124, and the power transmission mechanism 103. Some of it rejoins the oil passage 107 downstream of the second valve V2, and some of it returns to the oil reservoir 179. When the second valve V2 is in the open state, both the oil reservoir 179 and the oil passage 107 downstream of the second valve V2 are on the suction side of the oil pump 161. Therefore, the oil circulates through a path that passes through the oil pump 161, the oil cooler 162, the rotating electric machine 102, and the parts of the power transmission mechanism 103 that require lubrication. This path through which the oil circulates is the first circulation path 171. When the first circulation path 171 is formed, the second valve V2 is in the open state, so the first circulation path 171 is configured to pass through the oil reservoir 179.

[0068] The second circulation path 172 is formed when at least the first valve V1 is controlled to be in a closed state. Preferably, the second circulation path 172 is formed when both the first valve V1 and the second valve V2 are controlled to be in a closed state. When the second valve V2 is in a closed state, the oil pump 161 does not draw oil from the oil reservoir 179, but instead draws and discharges oil downstream of the second valve V2 and upstream of the oil pump 161. Because the first valve V1 is controlled to be in a closed state, the oil discharged from the oil pump 161 is not supplied to the oil passages formed inside the rotor shaft 120 of the rotating electric machine 102, nor to the lubrication targets of the power transmission mechanism 103, but is supplied to the stator coil 124. The oil supplied to the stator coil 124 flows downstream of the second valve V2 and upstream of the oil pump 161. That is, the oil circulates through a path that passes through the oil pump 161, the oil cooler 162, and the rotating electric machine 102. The path through which the oil circulates in this manner is the second circulation path 172. The second circulation path 172, which is formed when both the first valve V1 and the second valve V2 are controlled to a closed state, is configured so as not to pass through the oil reservoir 179.

[0069] In this embodiment, the stator 122 comprises a stator core 123, a stator coil 124 which is a coil wound around the stator core 123, and a stator cover 125 configured to cover at least the stator coil 124 and having an internal oil passage 173 through which oil flows. Figure 10 illustrates a configuration in which the stator cover 125 covers the stator coil 124, but the stator cover 125 may cover the entire stator 122. The oil supplied to the stator coil 124 is the oil supplied to the internal oil passage 173, and the portion of the second circulation path 172 that passes through the rotating electric machine 102 (oil passage 107) includes the internal oil passage 173. Therefore, the second circulation path 172 can be described as a path passing through the oil pump 161, the oil cooler 162, and the internal oil passage 173. Figure 10 illustrates a configuration in which only the oil passage 173 inside the cover passes through the rotating electric machine 102 in the second circulation path 172, but the second circulation path 172 may include other oil passages that pass through the rotating electric machine 102. The oil passage 173 inside the cover is an oil passage 107 formed inside the stator cover 125, which is configured to cover the stator coil 124. Therefore, except for oil that leaks out from gaps, the oil remains inside the second circulation path 172 and can circulate through the second circulation path 172. The second circulation path 172 can be described as a closed loop in the oil passage 107.

[0070] In other words, the second circulation path 172 can be described as a path configured to be filled with oil. However, if oil leaks out from gaps in the oil passage 107, gaps in the stator cover 125, etc., the amount of oil filled in the second circulation path 172 will decrease. As described above, the second valve V2 is located in the oil passage 107 between the oil pump 161 and the oil reservoir 179. In other words, the second valve V2 is configured to switch between a connected state in which the oil pump 161 and the oil reservoir 179 are connected, and a disconnected state in which the oil pump 161 and the oil reservoir 179 are disconnected. Therefore, if the amount of oil filled in the second circulation path 172 falls below a specified amount, that is, if the second circulation path 172 is not filled with oil, the control device 105 can connect the oil pump 161 and the oil reservoir 179 and replenish the oil in the second circulation path 172. The control device 105 can then control the second valve V2 to disconnect the oil pump 161 from the oil reservoir 179 after the second circulation path 172 has filled with oil. Alternatively, the second valve V2 may be controlled to be open continuously or intermittently. In addition, another valve (for example, a third valve) may be provided, and the second circulation path 172 and the oil reservoir 179 may be connected via this third valve. The controlled state of the third valve is the same as the controlled state of the second valve V2 when the second circulation path 172 is selected.

[0071] The oil cooler 162 performs heat exchange between the oil flowing through the oil passage 107 and the heat transfer medium. This oil passage 107 passing through the oil cooler 162 corresponds to both the first circulation path 171 and the second circulation path 172. Here, the heat transfer medium is a coolant such as LLC (Long Life Coolant). The oil cooler 162 also passes through a cooling water passage 166 through which cooling water flows. The cooling water passage 166 also passes through a radiator, for example, which is located at the front of the vehicle and performs heat exchange with the outside air, but the radiator and the passage to the radiator are omitted in Figure 10. Figure 10 illustrates a configuration in which the cooling water passage 166 circulates through the rotating electric motor drive unit 180, the water jacket 129 surrounding the stator 122 (stator core 123) of the rotating electric motor 102, the oil cooler 162, and the DC power supply 108.

[0072] The rotating electric drive unit 180, particularly the inverter 182, generates a large amount of heat due to the large current flowing through it. Similarly, the busbars electrically connecting the inverter 182 and the stator coil 124, and the smoothing capacitor 181, also generate a lot of heat. Therefore, in this embodiment, the rotating electric drive unit 180 is also equipped with a heat sink, and cooling water is configured to flow inside the heat sink. In addition, the stator core 123, around which the stator coil 124 through which the large current flows, also generates heat, so it is configured to exchange heat with a water jacket 129 through which cooling water flows. The water jacket 129 may be positioned to be in contact with the stator core 123, or it may be positioned to cover the stator cover 125 from the radial outside and be in contact with the stator cover 125 (oil passage 173 inside the cover). Furthermore, as described above, the lubricating oil also rises in temperature due to heat exchange with the lubrication and cooling targets in the vehicle drive unit 101, so it is configured to exchange heat between the oil passing through the oil cooler 162 and the cooling water. Furthermore, the DC power supply 108 also generates heat due to the current flowing during charging and discharging. For this reason, the DC power supply 108 is equipped with a battery cooler through which cooling water flows, and is configured to exchange heat between the cooling water and the battery.

[0073] In this explanation, cooling water was used as an example of the heat transfer medium for heat exchange between the oil and the oil in the oil cooler 162, but the heat transfer medium is not limited to cooling water. For example, the refrigerant used in an onboard air conditioner may be used as the heat transfer medium. Also, if the heat transfer medium is the refrigerant of the air conditioner, the "heat exchanger" is not limited to the oil cooler 162, but may be, for example, a chiller or a cabin condenser. Furthermore, it may be a configuration in which heat is exchanged between the oil and the cooling water in the first heat exchanger (e.g., the oil cooler 162), and heat is exchanged between the cooling water and the refrigerant in the second heat exchanger (e.g., a chiller).

[0074] Incidentally, when starting the vehicle drive system 101 that has been stopped during cold weather, or when charging the DC power supply 108 with power supplied from an external power source during cold weather, if the DC power supply 108 is cold, the DC power supply 108 may not be able to fully perform its discharge and charge functions. For this reason, it may be necessary to warm up the DC power supply 108. If the temperature of the coolant flowing through the cooling water passage 166 is higher than the temperature of the DC power supply 108, the DC power supply 108 can be warmed up by the coolant. The temperature of the coolant can be raised by heat exchange with the oil in the oil cooler 162. When the vehicle drive system 101 is stopped during cold weather, the oil is also cold, so it is preferable to quickly raise the oil temperature during such warm-up.

[0075] Although this example illustrates a configuration for warming up the DC power supply 108 during cold weather, the object that is heated using the heat from the oil (the destination for the waste heat) is not limited to the DC power supply 108; it may also be the vehicle's heating system (air conditioner). For example, the heat may be utilized in the chiller or cabin condenser of the air conditioner.

[0076] As described above, in this embodiment, the oil passage 107 in the vehicle drive unit 101 includes a first circulation path 171 and a second circulation path 172. The valve V circulates oil through the first circulation path 171 when the rotational speed of the output member 133 is higher than a predetermined reference speed (speed reference value), and circulates oil through the second circulation path 172 when the rotational speed of the output member 133 is less than or equal to the reference speed. In this embodiment, the valve V is an electromagnetically controlled valve, and the control device 105 controls the opening and closing state of the valve V based on the rotational speed corresponding to the rotational speed of the output member 133 (the rotational speed of the wheel 104, or, if linear, the rotational speed of any rotating member in the power transmission mechanism 103 or the rotational speed of the rotor 121 of the rotating electric machine 102). Figure 9 illustrates a rotation sensor 155 for detecting the rotational speed of the output member 133.

[0077] The second circulation path 172 is a path that does not pass through the parts of the power transmission mechanism 103 that are to be lubricated. Therefore, when the second circulation path 172 is formed, it is preferable that the rotating members of the power transmission mechanism 103 are rotating at a very low speed (for example, less than 5 km / h in terms of the vehicle's travel speed) or are stopped without rotating. Also, the second circulation path 172 is a path configured to be filled with oil, and a limited amount of oil circulates through it. Therefore, it is easy to raise the temperature of the oil flowing through the second circulation path 172. The rotating electric machine control device can control the inverter 182 so that the rotor 121 does not rotate while current is flowing to the stator coil 124. This makes it possible to generate heat in the inverter 182, busbar, stator coil 124, etc. without rotating the power transmission mechanism 103 or output member 133.

[0078] Furthermore, the second circulation path 172 is a path that passes through the stator coil 124, which is easily heated by energization, and does not pass through the low-temperature power transmission mechanism 103 or the low-temperature oil reservoir 179. As described above, when replenishing oil in the second circulation path 172, the second valve V2 is opened and oil is introduced from the oil reservoir 179 into the second circulation path 172. However, the oil in the second circulation path 172, i.e., the heated oil, is not configured to actively return to the oil reservoir 179 except for leaked oil. In other words, even when replenishing oil in the second circulation path 172 from the oil reservoir 179, the second circulation path 172 is not a path that passes through the oil reservoir 179.

[0079] Since the oil in the oil reservoir 179 is in contact with the case 109, which has a large heat capacity, heat from the oil easily escapes to the case 109 when the case 109 is cold. Also, the volume of oil stored in the oil reservoir 179 is greater than the amount of oil that fills the second circulation path 172, so it does not heat up easily. Because the second circulation path 172 does not pass through the oil reservoir 179, it is easier to raise the temperature of the oil flowing through the second circulation path 172. It should be noted that this rise in oil temperature is desirable when the oil temperature is low, so the second circulation path 172 is preferably selected when the oil temperature is below the oil temperature standard value. The oil temperature standard value is, for example, around 100 to 120 degrees Celsius.

[0080] Furthermore, if the oil temperature is too high, it may lead to oil deterioration. The second circulation path 172 is a closed path, and the amount of oil circulating through it is relatively small, so the oil temperature may become too high. By selecting the second circulation path 172 when the oil temperature is below the oil temperature standard value, it is possible to prevent the oil temperature from becoming too high.

[0081] The oil temperature to be determined can be detected in the oil reservoir 179, oil pump 161, oil cooler 162, etc. However, as described above, when the oil temperature needs to be raised, that is, when heat generation is necessary for the vehicle to warm up the DC power supply 108 or for heating by the air conditioner, it is selected to form a second circulation path 172 in which a closed loop is formed. Therefore, it is preferable that the oil temperature to be determined is the oil temperature in the second circulation path 172 (closed loop).

[0082] The following explanation will also refer to the flowchart in Figure 11. When selecting the oil flow path 107, the control device 105 first receives signals from various sensors, such as the rotation sensor 155 and the oil temperature sensor (not shown), and signals from the vehicle control device (not shown) indicating whether or not there is a heat generation request (#1). Upon receiving the signals, the control device 105 first determines whether or not there is a heat generation request (#2). If there is no heat generation request, the first valve V1 and the second valve V2 are both controlled to be in the open state, and oil is circulated through the first circulation path 171 (including the second circulation path 172) (#8). It is preferable that the initial setting of the valves V is that both the first valve V1 and the second valve V2 are in the open state.

[0083] If the control device 105 determines in step #2 that there is a heat generation request, it then determines whether the output rotational speed, which is the rotational speed of the output member 133, is less than or equal to the speed reference value (#3). As described above, the speed reference value is preferably a value less than 5 km / h when converted to the vehicle's travel speed. Step #2 may also be conditional on the vehicle being stopped, in which case the speed reference value is zero, for example. If it is determined in step #3 that the output rotational speed is higher than the speed reference value, it is necessary to supply oil to the lubrication target parts of the power transmission mechanism 103, so the control device 105 controls both the first valve V1 and the second valve V2 to be open, regardless of whether there is a heat generation request, and circulates oil in the first circulation path 171 (including the second circulation path 172) (#8).

[0084] If the control device 105 determines in step #3 that the output rotational speed is below the speed reference value, it then determines whether the closed-loop oil temperature, which is the temperature of the oil in the second circulation path 172, is below the oil temperature reference value (#4). If the closed-loop oil temperature is above the oil temperature reference value, there is no need to raise the oil temperature, so the first valve V1 and the second valve V2 are both controlled to be open, and oil is circulated through the first circulation path 171 (including the second circulation path 172) (#8).

[0085] In step #4, if it is determined that the closed-loop oil temperature is below the oil temperature reference value, then all the conditions are met: there is a heat generation request (#2), the output rotational speed is below the speed reference value (#3), and the closed-loop oil temperature is below the oil temperature reference value (#4). The control device 105 controls valve V so that it does not supply oil to the lubrication target parts of the power transmission mechanism 103, but only allows oil to flow through the second circulation path 172 (#6, #7). Here, prior to controlling valve V, the control device 105 determines whether or not the second circulation path 172 is filled with oil (#5). If the result of the closed-loop oil quantity sufficiency determination is true, the control device 105 determines that the second circulation path 172 is filled with oil. This determination may be made, for example, based on the detection result of a hydraulic sensor installed in the second circulation path 172 (the detection result is received in step #1), or based on a result estimated from the relationship between the results of a prior simulation and the current operating status.

[0086] If the control device 105 determines in step #5 that the result of the closed-loop oil quantity sufficiency determination is true, it controls both the first valve V1 and the second valve V2 to be closed, so that oil does not flow through the first circulation path 171 and oil flows only through the second circulation path 172 (#7). If the control device 105 determines in step #5 that the result of the closed-loop oil quantity sufficiency determination is not true, it controls both the first valve V1 and the second valve V2 to be closed, so that oil does not flow through the first circulation path 171, while allowing oil to be supplied from the oil storage unit 179 to the second circulation path 172 and allowing oil to flow through the second circulation path 172 (#6).

[0087] [Summary of the Second Embodiment] The vehicle drive system (101) described above will be briefly summarized below.

[0088] In one embodiment, the vehicle drive system (101) comprises a rotating electric machine (102), an output member (133) driven and connected to a wheel (104), a power transmission mechanism (103) that transmits power between the rotating electric machine (102) and the output member (133), a case (109) housing the rotating electric machine (102) and the power transmission mechanism (103), an oil pump (161), an oil passage (107) through which oil discharged from the oil pump (161) flows, a switching device (V) that switches the path through which oil flows in the oil passage (107), and a heat exchanger (162) that performs heat exchange between the oil flowing in the oil passage (107) and a heat transfer medium, wherein the oil passage (1 07) includes a first circulation path (171) through which oil circulates via a path passing through the oil pump (161), the heat exchanger (162), the rotating electric machine (102), and the lubrication required parts of the power transmission mechanism (103), and a second circulation path (172) through which oil circulates via a path passing through the oil pump (161), the heat exchanger (162), and the rotating electric machine (102) without passing through the lubrication required parts. The switching device (V) circulates oil through the first circulation path (171) when the rotational speed of the output member (133) is higher than a predetermined reference speed, and circulates oil through the second circulation path (172) when the rotational speed of the output member (133) is less than or equal to the reference speed.

[0089] With this configuration, when the rotational speed of the output member (133) is higher than the reference speed, the oil is circulated in the first circulation path (171), allowing both the rotating electric machine (102) and the power transmission mechanism (103), which require cooling and lubrication, to be appropriately cooled and lubricated. On the other hand, when the rotational speed of the output member (133) is below the reference speed, the oil is circulated in the second circulation path (172), and oil is not supplied to the power transmission mechanism (103), which has less need for cooling and lubrication. This allows the oil temperature to be efficiently raised through heat exchange with the rotating electric machine (102), and heat to be recovered by the heat exchanger (162). In other words, with this configuration, the vehicle drive system (101) can be appropriately cooled and lubricated using oil, and waste heat can be utilized via oil with higher utilization efficiency.

[0090] Furthermore, the vehicle drive unit (101) preferably includes a rotating electric machine (102) comprising a rotor (121) and a stator (122), wherein the stator (122) comprises a stator core (123), coils (124) wound around the stator core (123), and a stator cover (125) configured to cover at least the coils (124) and having an internal oil passage (173) through which oil flows, and the portion of the second circulation path (172) passing through the rotating electric machine (102) preferably includes the internal oil passage (173).

[0091] Of the parts of the rotating electric machine (102), the coil (124) is prone to becoming hot. With this configuration, the oil passage (173) inside the cover, where heat exchange takes place between the coil (124) and the oil, is included in the second circulation path (172), so when the rotational speed of the output member (133) is below the reference speed, the oil temperature can be increased efficiently.

[0092] Furthermore, it is preferable that the vehicle drive unit (101) has an oil reservoir (179) formed inside the case (109) where oil accumulates, the first circulation path (171) is configured to pass through the oil reservoir (179), and the second circulation path (172) is configured not to pass through the oil reservoir (179).

[0093] The oil in the oil reservoir (179) may decrease in temperature due to heat transfer to the case (109). Also, if the temperature of the oil stored in the oil reservoir (179) is low, the temperature of the oil that has exchanged heat with the rotating electric machine (102) may decrease as it mixes with the oil stored in the oil reservoir (179). With this configuration, since the second circulation path (172) does not pass through the oil reservoir (179), it is easier to retain the heat transferred to the oil from the heat exchange with the rotating electric machine (102), and heat can be efficiently recovered in the heat exchanger (162).

[0094] Furthermore, the vehicle drive unit (101) has an oil reservoir (179) formed inside the case (109) where oil accumulates, and the second circulation path (172) is configured to be filled with oil. The switching device (V) is configured to switch between a connected state in which the oil pump (161) and the oil reservoir (179) are connected, and a disconnected state in which the oil pump (161) and the oil reservoir (179) are disconnected. It is preferable to set the second circulation path (172) to the connected state when the rotational speed of the output member (133) is less than or equal to the reference speed, and to set it to the disconnected state after the second circulation path (172) is filled with oil.

[0095] With this configuration, since the second circulation path (172) is a path filled with oil, when the oil pump (161) is operated, oil can be properly circulated through the second circulation path (172). Furthermore, if the second circulation path (172) is not sufficiently filled with oil, the oil pump can draw in oil from the oil reservoir (179) to fill the second circulation path (172) with oil. By properly circulating oil through the second circulation path (172) in this way, the heat generated in the rotating electric machine (102) can be efficiently recovered in the heat exchanger (162) with a small amount of oil.

[0096] [Third Embodiment] An example of a vehicle drive system comprising a rotating electric machine, an output member driven and connected to a wheel, a power transmission mechanism for transmitting power between the rotating electric machine and the output member, the rotating electric machine, the power transmission mechanism, and a case containing oil, an oil storage section provided at the lower part of the case where the oil is stored, and an oil circuit for circulating the oil is disclosed in Japanese Patent Application Publication No. 2024-140085. Hereinafter, the reference numerals in the said document are cited in parentheses. In the vehicle drive system (100) of this document, an oil storage section (91) for storing oil is formed inside the case (9). The oil storage section (91) is equipped with an oil receiving section (92) for receiving oil after the rotating electric machine (MG) has been cooled. The oil receiving section (92) has higher heat insulation properties than other parts of the oil storage section (91). As a result, the heat from the oil stored in the oil receiving section (92) is less likely to be dissipated to the outside of the case (9), making it easier to improve the efficiency of heat utilization when using the heat from the oil.

[0097] As described above, the vehicle drive system disclosed in this document effectively utilizes the heat of oil heated by a rotating electric machine. However, it does not mention the utilization of the heat of oil heated by a power transmission mechanism, leaving room for further improvement in the heat utilization efficiency of vehicle drive systems.

[0098] Therefore, there is a need for a vehicle drive system that can effectively utilize the heat generated by the mechanical losses in the power transmission mechanism.

[0099] [First Example] Hereinafter, an embodiment of a vehicle drive system in view of the above will be described based on the drawings. In the following description, the direction of each component refers to the direction when the vehicle drive system 201 is assembled to a vehicle (not shown) (vehicle mounted state). In the vehicle mounted state, the direction along the rotation axis of the vehicle drive system 201 (in this embodiment, each axis is a separate axis parallel to each other (for example, the first axis A1, the second axis A2, the third axis A3, details will be described later)) is referred to as the axial direction L, and one side of the axial direction L is referred to as the axial first side L1, and the other side as the axial second side L2. Furthermore, the direction perpendicular to each of the above axes is referred to as the "radial direction" with respect to each axis.

[0100] As shown in Figure 12, the vehicle drive unit 201 includes a rotating electric motor MG, an output member 270 driven and connected to a wheel W, a power transmission mechanism GT that transmits power between the rotating electric motor MG and the output member 270, a case 210 (Figure 14) containing oil, an oil reservoir 209 provided at the bottom of the case 210 where oil is stored, and an oil circuit 203 for circulating the oil. The rotating electric motor MG is the driving force source of the vehicle, and the power transmission mechanism GT includes a counter gear mechanism 204 and a differential gear mechanism 205. The rotating electric motor MG includes a rotor 221. The rotor 221 is arranged on a first shaft A1. Furthermore, a rotor output gear 231 that rotates integrally with the rotor 221 is arranged on the first shaft A1. The differential gear mechanism 205 is located on a second axis A2 that is parallel to the first axis A1 and different from the first axis A1. The counter gear mechanism 204 is located on a third axis A3 that is parallel to the first axis A1 and the second axis A2 and different from the first axis A1 and the second axis A2, and includes a first counter gear 241 that meshes with the rotor output gear 231, and a second counter gear 242 that rotates integrally with the first counter gear 241 and meshes with the differential input gear 251.

[0101] Here, "rotating electric machine" is used as a concept that includes motors, generators, and motor-generators that perform both motor and generator functions as needed. Furthermore, "drive connection" refers to a state in which two rotating elements are connected in a manner that can transmit driving force, and is used as a concept that includes a state in which the two rotating elements are connected so as to rotate as a whole, or a state in which the two rotating elements are connected in a manner that can transmit driving force via one or more transmission members. Such transmission members include various members that transmit rotation at the same speed or at a variable speed, such as shafts, gear mechanisms, belts, chains, etc. Also, such transmission members may include engagement devices that selectively transmit rotation and driving force, such as friction engagement devices and meshing engagement devices.

[0102] A rotating electric machine (MG) is a motor / generator that operates using, for example, multi-phase alternating current (e.g., three-phase alternating current), and can function as both an electric motor and a generator. The rotating electric machine (MG) is powered by a DC power source, or it generates power using the inertia of the vehicle and supplies that power back to the DC power source (regenerative braking).

[0103] The rotating electric machine MG has a stator 223 fixed to a case 210 or the like, and a rotor 221 rotatably supported radially inward of the stator 223. In this embodiment, the stator 223 includes a stator core 224 and a stator coil 225 wound around the stator core 224, and the rotor 221 includes a rotor core 222 and permanent magnets (not shown) arranged on the rotor core 222. The stator coil 225 is wound around the stator core 224, and at the axial end L of the stator 223, a coil end portion 225e is formed where the bent portion of the wound stator coil 225 protrudes axially L from the stator core 224.

[0104] The rotor 221 of the rotating electric machine MG is connected to a rotor shaft 220 that rotates integrally with the rotor 221. A rotor connecting shaft 230 is connected to the rotor shaft 220 so as to rotate integrally with the rotor shaft 220. The rotor shaft 220 is rotatably supported by the case 210 via rotor bearings, and the rotor connecting shaft 230 is rotatably supported by the case 210 via input bearings. A rotor output gear 231 is provided on the rotor connecting shaft 230 so as to rotate integrally with the rotor connecting shaft 230. As will be described later, the rotor output gear 231 meshes with the first counter gear 241 of the counter gear mechanism 204.

[0105] The differential gear mechanism 205 is positioned on the second shaft A2 and distributes the driving force transmitted from the rotating electric machine MG to a pair of wheels W. In this embodiment, the differential gear mechanism 205 is composed of a plurality of bevel gears (pinion gear 253, differential output gear 254) that mesh with each other, and a differential case 252 that houses the plurality of bevel gears. The differential case 252 is connected to the differential input gear 251 so as to rotate integrally with it and supports the pinion shaft 255. The differential gear mechanism 205 transmits the rotation and torque input to the differential input gear 251 from the rotating electric machine MG to the pinion shaft 255, which is positioned along the radial direction of the second shaft A2 and rotates integrally with the differential input gear 251, and distributes and transmits it to a pair of output members 270 via a pair of differential output gears 254 that mesh with the pinion gear 253, which is rotatably supported on the pinion shaft 255.

[0106] The counter gear mechanism 204 is positioned on the third shaft A3 and drives and connects the rotating electric machine MG and the differential gear mechanism 205 (differential input gear 251) via the rotor output gear 231. In this embodiment, the counter gear mechanism 204 is configured to have a first counter gear 241 and a second counter gear 242 connected by a counter connecting shaft 240. The first counter gear 241 meshes with the rotor output gear 231, and the second counter gear 242, which is connected to the first counter gear 241 by the counter connecting shaft 240, meshes with the differential input gear 251. The counter connecting shaft 240 is rotatably supported relative to the case 210. The power transmission mechanism GT may also include engagement elements such as clutches and brakes in addition to the differential gear mechanism 205 and the counter gear mechanism 204. Furthermore, the power transmission mechanism GT may not include either or both of the differential gear mechanism 205 and the counter gear mechanism 204. For example, in the case of an in-wheel motor type vehicle drive system 201, the power transmission mechanism GT does not have a differential gear mechanism 205, and the rotation of the rotating electric machine MG is transmitted to a single output member 270 (an output shaft connected to the wheel W).

[0107] As shown in Figure 13, the rotating electric machine MG is driven and controlled by the rotating electric machine control unit H2 based on the target torque of the rotating electric machine MG, which is set according to a command from the vehicle control device 500, which is a higher-level control device. The rotating electric machine control unit H2 controls the switching of an inverter circuit (inverter module) composed of multiple switching elements to convert power between DC and multi-phase (in this case, 3-phase) AC in the inverter circuit. For example, the inverter circuit, including the freewheel diode, is integrated into a single power module. In addition, a DC link capacitor (not shown) is provided on the DC side of the inverter circuit as a smoothing capacitor to smooth the voltage between the positive and negative poles (DC link voltage). When the rotating electric machine MG is driven, a large current flows through the switching elements that make up the inverter circuit, causing the switching elements to heat up. For this reason, in this example, a cooling water circuit CX is provided to cool these switching elements.

[0108] An oil reservoir 209 is formed at the bottom of the case 210, into which oil used for lubrication and cooling falls and is stored. The oil stored in the oil reservoir 209 can be supplied to at least the power transmission mechanism GT by circulating through the oil circuit 203. The oil reservoir 209 is formed from the wall of the case 210, which is made of metal (for example, aluminum). Therefore, the heat from the oil stored in the oil reservoir 209 is easily dissipated through the outer wall of the case 210.

[0109] As shown in Figure 14, the vehicle drive unit 201 further includes a heat exchanger 206 that performs heat exchange between the oil flowing in the oil circuit 203 and a heat transfer medium, a waste heat utilization unit 219 that utilizes the heat of the heat transfer medium, and a collection unit 207 that collects the oil that has passed through the power transmission mechanism GT. In this embodiment, in addition to the oil stored in the oil storage unit 209, the oil stored in the collection unit 207 can also be circulated through the oil circuit 203 and supplied to their respective destinations. The oil circuit 203 is configured to flow the oil stored in the oil storage unit 209 and the collection unit 207 to the heat exchanger 206. In this example, an oil cooler OC is used as the heat exchanger 206. The oil cooler OC is provided in the oil circuit 203 and performs heat exchange between the oil and the cooling water in the cooling water circuit CX. That is, in this embodiment, the cooling water corresponds to the "heat transfer medium". The waste heat utilization unit 219 includes a refrigerant circuit for circulating refrigerant for the air conditioner and a water-cooled condenser 250 (Figure 14). The water-cooled condenser 250 is configured to perform heat exchange between the refrigerant in the refrigerant circuit and the coolant in the coolant circuit CX. Thus, in this embodiment, the waste heat utilization unit 219 is configured to utilize the heat of the coolant for heating the passenger compartment. However, for example, the waste heat utilization unit 219 may be configured to utilize the heat of the coolant for temperature control of a battery mounted in the vehicle (for example, a battery that supplies power to the rotating electric motor MG). In this case, for example, the waste heat utilization unit 219 includes a heat exchanger that performs heat exchange between the refrigerant and the battery coolant (coolant for temperature control of the battery). Note that the heat transfer medium that exchanges heat with oil in the heat exchanger 206 is not limited to the coolant in the coolant circuit CX, but may be, for example, the refrigerant or the battery coolant.

[0110] In this embodiment, the oil circuit 203 includes an oil pump OP that sucks and discharges oil from the oil storage section 209 and the collection section 207. The oil pump OP pumps up the oil stored in the oil storage section 209 and the collection section 207 and supplies the oil to the rotating electric machine MG and the power transmission mechanism GT. In this example, the oil circuit 203 is located inside the case 210 and not outside the case 210, however, a part of the oil circuit 203 may be located outside the case 210. Note that the oil pump OP is not necessarily provided, and instead of the oil pump OP, the oil may be circulated by scooping up the oil from the oil storage section 209 and the collection section 207. In this example, the collection section 207 includes a heat-insulating storage chamber 216 and a heat-insulating storage chamber 212. The heat-insulating storage chamber 216 and the heat-insulating storage chamber 212 are capable of storing oil that has been heated by cooling the power transmission mechanism GT.

[0111] As shown in Figure 14, in this embodiment, the oil circuit 203 includes a first oil passage 203a (rotating electric machine circulation path) that supplies oil to the rotating electric machine MG, and a second oil passage 203b (power transmission mechanism circulation path) that branches off from the first oil passage 203a and supplies oil to the power transmission mechanism GT. Here, the vehicle drive unit 201 includes a heat-insulating section 218 located in the first oil passage 203a. In this example, the oil pumped up by the oil pump OP in the first oil passage 203a passes through the oil cooler OC and flows into the rotating electric machine MG. After cooling the rotating electric machine MG, the oil is stored in the heat-insulating section 218 and then pumped up again by the oil pump OP and circulates through the first oil passage 203a. The heat-insulating section 218 has a structure that provides higher heat insulation than the oil storage section 209. The structure of the heat-insulating section 218 will be described later. In this way, the oil heated by cooling the rotating electric machine MG is stored in the heat retention section 218. Therefore, the heat from the oil is less likely to dissipate, and the efficiency of heat exchange in the waste heat utilization section 219 can be improved. In this example, the second oil passage 203b branches off from the first oil passage 203a on the upstream side and rejoins the first oil passage 203a on the downstream side.

[0112] As shown in Figure 14, the oil circuit 203 includes a supply passage 213 that supplies oil collected by the collection unit 207 to the heat exchanger 206. The oil circuit 203 also includes a switching mechanism 208 that switches between sending oil that has passed through the power transmission mechanism GT to the supply passage 213 after being collected by the collection unit 207, or to the oil storage unit 209. The oil circuit 203 also includes an adjustment mechanism 211 provided between the oil storage unit 209 and the collection unit 207 and the oil pump OP, which adjusts the ratio between the amount of oil supplied from the oil storage unit 209 to the oil pump OP and the amount of oil supplied from the collection unit 207 to the oil pump OP. In this example, the switching mechanism 208 and the adjustment mechanism 211 are provided in the second oil passage 203b.

[0113] In this example, the first solenoid valve 215 is positioned at the connection point between the first oil passage 203a and the upstream end of the second oil passage 203b (downstream of the oil cooler OC, at the branching point between the oil passage leading to the power transmission mechanism GT and the oil passage leading to the rotating electric machine MG). When the first solenoid valve 215 is open, the oil pumped up by the oil cooler OC can enter the second oil passage 203b in addition to the oil passage leading to the rotating electric machine MG in the first oil passage 203a. The second oil passage 203b is connected downstream of the first solenoid valve 215 to the area where the power transmission mechanism GT is located. Furthermore, in this example, as shown in Figure 14, the power transmission mechanism GT is housed in a heat-insulating chamber 216 inside the case 210. The heat-insulating chamber 216 has a structure that provides higher heat insulation than the oil storage section 209. The second oil passage 203b is connected to the power transmission mechanism GT via a heat-insulating chamber 216 downstream of the first solenoid valve 215. As shown in Figure 14, the heat-insulating chamber 216 can store oil that has branched off from the first oil passage 203a. This cools the power transmission mechanism GT and prevents the heat from the heated oil from being easily dissipated. Note that the heat-insulating chamber 216 does not necessarily have to be configured to store oil. Alternatively, a part of the power transmission mechanism GT may be located in the heat-insulating chamber 216.

[0114] Downstream (in this case, below) the heat-insulating storage chamber 216 is a heat-insulating storage chamber 212 for storing oil used to lubricate and cool the power transmission mechanism GT. In this example, the heat-insulating storage chamber 212 is provided separately from the wall portion of the case 210 (the component constituting the oil storage section 209). In the illustrated example, the heat-insulating storage chamber 212 is positioned adjacent to the oil storage section 209 at the bottom of the case 210. The heat-insulating storage chamber 216, the heat-insulating storage chamber 212, and the oil storage section 209 are connected by a branched connecting oil passage of the second oil passage 203b. Here, the path of the second oil passage 203b connecting these is branched by a switching mechanism 208. In this example, the switching mechanism 208 is a second solenoid valve 208a. By switching the open / closed state of the second solenoid valve 208a, it is possible to switch whether the oil stored in the heat-insulating storage chamber 216 enters the heat-insulating storage chamber 212 or enters the oil storage section 209.

[0115] The supply passage 213 is an oil passage that supplies oil stored in the collection section 207 to the heat exchanger 206 (oil cooler OC). In the example shown in Figure 14, the supply passage 213 connects the heat-insulating storage chamber 212 to the adjustment mechanism 211 located downstream of the heat-insulating storage chamber 212. In this example, the supply passage 213 includes an oil passage connecting the heat-insulating storage chamber 212 located in the second oil passage 203b (here, the bottom of the heat-insulating storage chamber 212) to the confluence point 214 where the second oil passage 203b merges with the first oil passage 203a (the point where the downstream end of the second oil passage 203b is connected to the first oil passage 203a), and an oil passage from the confluence point 214 to the oil cooler OC.

[0116] Furthermore, in the supply passage 213, a second connecting oil passage 233 is arranged parallel to the oil passage (first connecting oil passage 232) that connects the heat-insulating storage chamber 212 and the adjustment mechanism 211, and connects the oil storage section 209 (in this case, the bottom of the oil storage section 209) and the adjustment mechanism 211. The first connecting oil passage 232 and the second connecting oil passage 233 merge at the adjustment mechanism 211. The aforementioned merging point 214 is located downstream of the adjustment mechanism 211. The adjustment mechanism 211 is a third solenoid valve 211a (three-way valve) and is configured to adjust the ratio between the flow rate of oil flowing from the first connecting oil passage 232 toward the merging point 214 and the flow rate of oil flowing from the second connecting oil passage 233 toward the merging point 214.

[0117] The collection section 207 has a structure with higher thermal insulation properties than the oil storage section 209. In this embodiment, the heat-insulating storage chamber 216 and the heat-insulating storage chamber 212 are formed of a thermal insulation member 217 made of a thermal insulation material such as resin, but are not limited to this, and may be formed of a material with relatively low thermal conductivity, such as stainless steel. In addition, the constituent members of the heat-insulating storage chamber 216 and the heat-insulating storage chamber 212 may have a double structure with a thermal insulation layer such as an air layer or a vacuum layer in between, thereby providing a highly thermally insulating configuration. In this example, the heat-insulating storage chamber 216 and the heat-insulating storage chamber 212 and the heat-insulating section 218 described above are formed of the same material (thermal insulation member 217), but they may have different structures from each other. In addition, for example, the heat-insulating storage chamber 212 may be formed integrally with the wall portion of the case 210. In such a case, it is preferable that the wall portion of the case 210 constituting the heat-insulating storage chamber 212 has a thermal insulation structure. For example, it is preferable that an insulating material is provided on the inside of the wall portion of the case 210 in the heat-insulating storage chamber 212. In contrast, the oil storage section 209 is formed from the material that constitutes the wall portion of the case 210 and does not have an insulating structure like the collection section 207 (heat-insulating storage chamber 216 and heat-insulating storage chamber 212) and the heat-insulating section 218. Therefore, the oil stored in the oil storage section 209 is easily dissipated to the outside from the wall portion of the case 210. The collection section 207 may be configured to include only one of the heat-insulating storage chamber 216 or the heat-insulating storage chamber 212. Alternatively, the collection section 207 may be configured to include the heat-insulating section 218 in addition to the heat-insulating storage chamber 216 and the heat-insulating storage chamber 212.

[0118] As will be described later with reference to Figure 18 (S06), the switching mechanism 208 is configured to collect oil in the collection unit 207 and send it to the supply passage 213 when the target oil temperature T10, which is the temperature of the oil that has passed through the power transmission mechanism GT, is lower than the switching threshold Ts, and to send the oil to the oil storage unit 209 when the target oil temperature T10 is equal to or greater than the switching threshold Ts. In this embodiment, the collection unit 207 is equipped with a heat-insulating storage chamber 216 and a heat-insulating storage chamber 212, and the oil that has passed through the power transmission mechanism GT is collected in the heat-insulating storage chamber 216. When the target oil temperature T10 is lower than the switching threshold Ts, the oil collected in the heat-insulating storage chamber 216 is sent from the switching mechanism 208 to the heat-insulating storage chamber 212. As a result, the oil that has passed through the power transmission mechanism GT is collected in the heat-insulating storage chamber 212. The oil collected in the heat-insulating storage chamber 212 is sent to the supply passage 213 via the first connecting oil passage 232. On the other hand, if the target oil temperature T10 is equal to or greater than the switching threshold Ts, the oil collected in the heat-insulating storage chamber 216 is sent to the oil storage section 209 from the switching mechanism 208. As a result, the oil that has passed through the power transmission mechanism GT is sent to the oil storage section 209.

[0119] In this embodiment, the target oil temperature T10 is the temperature of the oil collected in the heat-insulating storage chamber 216 (in this example, the oil stored in the heat-insulating storage chamber 216 after lubricating and cooling the power transmission mechanism GT). Here, a temperature sensor (not shown) is provided in the oil-storage portion of the heat-insulating storage chamber 216, which can measure the target oil temperature T10. The switching threshold Ts is set to the lower limit of the temperature range where oil cooling must be prioritized over the utilization of heat generated by the mechanical losses of the power transmission mechanism GT. Alternatively, the temperature of the oil-storage portion of the heat-insulating storage chamber 212 may be measured as the target oil temperature T10 instead of the heat-insulating storage chamber 216. The switching threshold Ts is preferably set based on, for example, the oil temperature when the vehicle is running normally (for example, around 60°C). In that case, the switching threshold Ts is preferably set within the range of, for example, 80°C to 100°C. This reduces the possibility of oil overheating.

[0120] The adjustment mechanism 211 adjusts the ratio of the amount of oil supplied from the oil storage section 209 to the oil pump OP and the amount of oil supplied from the collection section 207 to the oil pump OP, based on at least one of the amount of oil in the oil storage section 209 (second oil amount VB) and the amount of oil in the collection section 207 (first oil amount VA), so that the amount of oil sucked by the oil pump OP is not insufficient. In this embodiment, the first oil amount VA is the amount of oil in the heat-insulating storage chamber 212. In this example, the adjustment mechanism 211 adjusts the ratio of the amount of oil flowing from the oil storage section 209 downstream of the adjustment mechanism 211 (in this case, the third solenoid valve 211a) and the amount of oil flowing from the collection section 207 (in this case, the heat-insulating storage chamber 212) downstream of the adjustment mechanism 211, based on both the amount of oil in the oil storage section 209 and the amount of oil in the heat-insulating storage chamber 212. In this example, the adjustment mechanism 211 can adjust the above ratio depending on whether the first oil amount VA is less than the first threshold Vt and whether the second oil amount VB is less than the second threshold Vs, so that the oil pump OP does not suck in air due to at least one of the first oil amount VA and the second oil amount VB being too small. The respective values ​​of the first oil amount VA and the second oil amount VB are estimated from experimental values ​​based on, for example, the driving time of the oil pump OP, the rotational speed, the oil temperature (viscosity), and the operating state of the second solenoid valve 208a and the third solenoid valve 211a. In this example, the above ratio is adjusted by appropriately switching between a state in which oil in the oil reservoir 209 is sucked in by the oil pump OP and a state in which oil in the heat-insulating storage chamber 212 is sucked in by the oil pump OP using the third solenoid valve 211a. However, for example, oil may always be sucked in from the heat-insulating storage chamber 212, and the presence or absence of oil sucking in from the oil reservoir 209 may be switched. Furthermore, the above ratio may be adjusted by switching the valve in the second solenoid valve 208a (switching mechanism 208).

[0121] As illustrated by the dashed line in Figure 14, an oil cooler OC2 for cooling the oil flowing from the oil storage section 209 may be separately provided in the second connecting oil passage 233. Alternatively, an oil storage section 209 for storing oil after cooling the power transmission mechanism GT may not be formed, and instead, an oil cooler OC2 may be separately provided in the second connecting oil passage 233. In that case, the second connecting oil passage 233 is directly connected to the second solenoid valve 208a without going through the oil storage section 209. In this embodiment, by supplying the oil stored in the heat-insulating storage chamber 212 and the heat-insulating section 218 to the oil cooler OC that constitutes the heat exchanger 206, the heat generated by cooling the power transmission mechanism GT and the rotating electric machine MG can be efficiently reused. On the other hand, if the target oil temperature T10 exceeds the switching threshold Ts, the oil is circulated through an oil passage (an oil passage via the oil reservoir 209) that allows heat to be easily dissipated to the outside of the case 210, thereby reducing the possibility of oil overheating.

[0122] In this embodiment, the vehicle drive unit 201 further includes an oil circuit control unit H1 (Figure 13) that can communicate with the vehicle control device 500. The functions of the oil circuit control unit H1 are realized through the cooperation of hardware such as a microcomputer and software (program). The oil circuit control unit H1 is configured to control at least the switching mechanism 208 and adjustment mechanism 211 described above. Specifically, as shown in Figure 18, when the vehicle is in a stationary mode (S01: Yes), the oil circuit control unit H1 closes the first solenoid valve 215 (indicated simply as "closed" in Figures 18-20) (S02), opens the heat retention storage chamber 212 side (side A) of the second solenoid valve 208a (indicated simply as "open" in Figures 18-20), and closes the oil storage section 209 side (side B) (S03). Then, the oil circuit control unit H1 closes the side of the third solenoid valve 211a that connects to the first oil passage 232 (side A) and also closes the side that connects to the second oil passage 233 (side B) (S04). The side of the second solenoid valve 208a that connects to the oil reservoir 209 (side B) may be left open or closed. In this way, the oil circuit control unit H1 circulates oil through the first oil passage 203a regardless of whether the vehicle is in a stopped mode or not. In Figure 18, the first solenoid valve 215 is labeled as "valve 1", the second solenoid valve 208a as "valve 2", and the third solenoid valve 211a as "valve 3".

[0123] If the oil circuit control unit H1 is not in a stopped mode (S01: No), it opens the first solenoid valve 215 (S05). This supplies oil to the second oil passage 203b. The oil circuit control unit H1 then determines whether the target oil temperature T10 is lower than the switching threshold Ts (S06). If the oil circuit control unit H1 determines that the target oil temperature T10 is lower than the switching threshold Ts (S06: Yes), it opens side A of the second solenoid valve 208a and closes side B (S07). Subsequently, the oil circuit control unit H1 determines whether the second oil volume VB is lower than the second threshold Vs (S08). If the oil circuit control unit H1 determines that the second oil volume VB is lower than the second threshold Vs (S08: Yes), it opens side A of the third solenoid valve 211a and closes side B (S09). Furthermore, if the oil circuit control unit H1 determines that the second oil quantity VB is equal to or greater than the second threshold Vs (S08: No), it opens both the A side and the B side of the third solenoid valve 211a (S10). This allows the amount of oil stored in the oil reservoir 209 to be adjusted. Naturally, the state of the third solenoid valve 211a may also be changed depending on whether the first oil quantity VA is lower than the first threshold Vt.

[0124] If the oil circuit control unit H1 determines that the target oil temperature T10 is equal to or greater than the switching threshold Ts (S06: No), it closes side A of the second solenoid valve 208a and opens side B (S11). This allows oil to be circulated through the oil passage that dissipates heat easily (the oil passage that passes through the oil storage section 209). Subsequently, the oil circuit control unit H1 determines whether the first oil volume VA is lower than the first threshold Vt (S12). If the oil circuit control unit H1 determines that the first oil volume VA is lower than the first threshold Vt (S12: Yes), it closes side A of the third solenoid valve 211a and opens side B (S13). If the oil circuit control unit H1 determines that the first oil volume VA is equal to or greater than the first threshold Vt (S12: No), it opens both side A and side B of the third solenoid valve 211a (S14). This allows the amount of oil stored in the heat-insulating storage chamber 212 to be adjusted. Naturally, the state of the third solenoid valve 211a may be changed depending on whether the second oil amount VB is lower than the second threshold value Vs.

[0125] [Second Example] The vehicle drive system 201 according to the second example will be described with reference to Figures 15 and 19. The following description will focus on the differences from the first example described above. Unless otherwise specified, the same applies as in the embodiment of the first example.

[0126] In this embodiment, as shown in Figure 15, both the oil used to cool the rotating electric machine MG and the oil used to lubricate and cool the power transmission mechanism GT are stored in the heat-insulating storage chamber 212. Here, the bottom of the heat-insulating storage chamber 216 is connected to the upper end of the heat-insulating storage chamber 212. The oil used to lubricate and cool the power transmission mechanism GT flows into the heat-insulating storage chamber 212 from the bottom of the heat-insulating storage chamber 216 after falling to the bottom of the heat-insulating storage chamber 216. The heat-insulating storage chamber 216 is also equipped with an opening / closing mechanism 208b as a switching mechanism 208. Here, the opening / closing mechanism 208b is provided on the bottom and side of the heat-insulating storage chamber 216, allowing it to be switched between a state in which the bottom and side of the heat-insulating storage chamber 216 are open (open state) and a state in which the bottom and side of the heat-insulating storage chamber 216 are closed (closed state). When the opening / closing mechanism 208b is in the closed position, as described above, the oil that lubricates and cools the power transmission mechanism GT flows from the bottom of the heat-insulating storage chamber 216 into the heat-insulating storage chamber 212, and does not flow into the oil storage section 209. In contrast, when the opening / closing mechanism 208b is in the open position, the oil that lubricates and cools the power transmission mechanism GT flows from the bottom and sides of the heat-insulating storage chamber 216 into the oil storage section 209 outside the heat-insulating storage chamber 216 (dashed line in Figure 15). In this example, the target oil temperature T10 is the temperature of the oil stored in the heat-insulating storage chamber 212.

[0127] In this embodiment, the adjustment mechanism 211 adjusts the ratio of the amount of oil supplied from the oil storage section 209 to the oil pump OP and the amount of oil supplied from the collection section 207 (here, the heat-insulating storage chamber 212) to the oil pump OP, based on the amount of oil in the oil storage section 209 (second oil amount VB), so that the amount of oil sucked by the oil pump OP is not insufficient. Here, the adjustment mechanism 211 (third solenoid valve 211a) is connected to the second connecting oil passage 233 connected to the oil storage section 209, and is not connected to the first connecting oil passage 232 connected to the heat-insulating storage chamber 212. Therefore, the adjustment mechanism 211 adjusts the flow rate of oil in the second connecting oil passage 233 so that the amount of oil in the oil storage section 209 is insufficient and air is not mixed into the oil circuit 203.

[0128] As shown in Figure 19, when the vehicle is in a stationary mode (S21: Yes), the oil circuit control unit H1 closes the first solenoid valve 215 (S22) and also closes the opening / closing mechanism 208b (S23). Then, the oil circuit control unit H1 closes the third solenoid valve 211a (S24).

[0129] Furthermore, if the oil circuit control unit H1 is not in a stopped mode (S21: No), it opens the first solenoid valve 215 (S25). Then, if the oil circuit control unit H1 determines that the target oil temperature T10 is lower than the switching threshold Ts (S26: Yes), it closes the opening / closing mechanism 208b (S27). As a result, the oil that lubricates and cools the power transmission mechanism GT is stored in the heat-insulating storage chamber 212 without flowing out into the oil storage section 209. Subsequently, if the oil circuit control unit H1 determines that the second oil quantity VB is lower than the second threshold Vs (S28: Yes), it closes the third solenoid valve 211a (S29). Also, if the oil circuit control unit H1 determines that the second oil quantity VB is equal to or greater than the second threshold Vs (S28: No), it opens the third solenoid valve 211a (S30).

[0130] Furthermore, if the oil circuit control unit H1 determines that the target oil temperature T10 is equal to or greater than the switching threshold Ts (S26: No), it opens the opening / closing mechanism 208b (S31). As a result, the oil that lubricates and cools the power transmission mechanism GT is stored in the oil storage section 209. Note that even when the opening / closing mechanism 208b is open, a portion of the oil that lubricates and cools the power transmission mechanism GT may be configured to flow out into the heat-insulating storage chamber 212. Here, if the oil circuit control unit H1 determines that the second oil amount VB is lower than the second threshold Vs (S32: Yes), it closes the third solenoid valve 211a (S33). Also, if the oil circuit control unit H1 determines that the second oil amount VB is equal to or greater than the second threshold Vs (S32: No), it opens the third solenoid valve 211a (S34).

[0131] [Third Example] The vehicle drive system 201 according to the third example will be described with reference to Figures 16 and 18. The following description will focus on the differences from the first example described above. Unless otherwise specified, the same principles apply as in the first example.

[0132] In this embodiment, as shown in Figure 16, the heat-insulating storage chamber 212 is formed at the bottom of the heat-insulating storage chamber 216. In the illustrated example, the heat-insulating storage chamber 212 and the heat-insulating storage chamber 216 are integrally formed. The heat-insulating section 218 is also arranged adjacent to the heat-insulating storage chamber 212. The heat-insulating storage chamber 216 is also provided with an opening / closing mechanism 208b as a switching mechanism 208. Here, the opening / closing mechanism 208b is provided at the bottom and sides of the heat-insulating storage chamber 216, thereby allowing switching between a state in which the bottom (bottom of the heat-insulating storage chamber 212) and sides of the heat-insulating storage chamber 216 are open (open state) and a state in which the bottom and sides of the heat-insulating storage chamber 216 are closed (closed state). When the opening / closing mechanism 208b is closed, the oil that lubricates and cools the power transmission mechanism GT does not flow out from the heat-insulating storage chamber 216 to the oil storage section 209, but is stored in the heat-insulating storage chamber 212. When the opening / closing mechanism 208b is open, the oil that lubricates and cools the power transmission mechanism GT does not flow out into the heat-insulating storage chamber 212 because the heat-insulating storage chamber 212 is opened, but is instead stored in the heat-insulating storage chamber 212 and flows out into the oil storage section 209. Thus, in this embodiment, the opening / closing mechanism 208b is used instead of the second solenoid valve 208a, and the only difference from the first example in the control flow of the oil circuit control unit H1 is (S03, S07, S11) in Figure 18 relating to the second solenoid valve 208a. Accordingly, in this embodiment, "Valve 2: A open, B closed" in (S03) and (S07) of Figure 18 shall be read as "Opening / closing mechanism: closed", and "Valve 202: B open, A closed" in (S11) shall be read as "Opening / closing mechanism: open".

[0133] [Fourth Example] The vehicle drive system 201 according to the fourth example will be described with reference to Figures 17 and 20. The following description will focus on the differences from the second example described above. Unless otherwise specified, the same principles apply as in the second example.

[0134] In this embodiment, as shown in Figure 17, a heat-insulating storage chamber 212 is formed at the bottom of the heat-insulating storage chamber 216. The heat-insulating storage chamber 212 is configured to store both the oil used to lubricate and cool the power transmission mechanism GT and the oil used to cool the rotating electric machine MG. Furthermore, the heat-insulating storage chamber 212 is configured so that a rotating member (for example, a differential input gear 251, etc.) of the power transmission mechanism GT can scoop up the oil stored in the heat-insulating storage chamber 212. In the illustrated example, the area in the heat-insulating storage chamber 212 from which the oil is scooped up by the power transmission mechanism GT is shallower than the other areas. Also, when the opening / closing mechanism 208b is open, the oil in the oil storage section 209 and the oil in the heat-insulating storage chamber 212 are scooped up in a mixed state, and the oil scooped up in this way by the rotating member of the power transmission mechanism GT is supplied to the power transmission mechanism GT to lubricate and cool it. Furthermore, although the adjustment mechanism 211 is not provided in this embodiment, sufficient oil volume is ensured because the oil is stirred up by the power transmission mechanism GT. Also, the target oil temperature T10 is the temperature of the oil stored in the heat-insulating storage chamber 212.

[0135] As shown in Figure 20, if the oil circuit control unit H1 determines that the vehicle is in a stopped mode (S41: Yes), it closes the opening / closing mechanism 208b (S42). If the oil circuit control unit H1 determines that the vehicle is not in a stopped mode (S41: No), it determines whether the target oil temperature T10 is lower than the switching threshold Ts (S43). If the oil circuit control unit H1 determines that the target oil temperature T10 is lower than the switching threshold Ts (S43: Yes), it closes the opening / closing mechanism 208b (S44). Conversely, if the oil circuit control unit H1 determines that the target oil temperature T10 is equal to or greater than the switching threshold Ts (S43: No), it opens the opening / closing mechanism 208b (S45). As a result, the oil that lubricates and cools the power transmission mechanism GT is stored in the oil reservoir 209.

[0136] [Other Embodiments of the Third Embodiment] (1) In the above embodiment, a vehicle drive system 201 with a three-axis configuration consisting of a first axle A1, a second axle A2, and a third axle A3 was described as an example. However, the vehicle drive system 201 is not limited to such a configuration, and may have a one-axis configuration, a two-axis configuration, or a configuration of four or more axes.

[0137] (2) In the above embodiment, the switching mechanism 208 was described as having a configuration in which, when the target oil temperature T10, which is the temperature of the oil that has passed through the power transmission mechanism GT, is lower than the switching threshold Ts, the oil is collected in the collection unit 207 and sent to the supply passage 213, and when the target oil temperature T10 is equal to or greater than the switching threshold Ts, the oil is sent to the oil storage unit 209. However, the mechanism is not limited to this configuration. The switching mechanism 208 can also be configured to send oil to both the oil storage unit 209 and the collection unit 207 when the target oil temperature T10 is equal to or greater than the switching threshold Ts.

[0138] (3) In the above embodiment, a temperature sensor (not shown) is provided in the oil storage portion of the heat-insulating storage chamber 216, and a configuration in which the target oil temperature T10 is measured by this sensor has been described as an example, but the invention is not limited to this. Instead of the measured value of the target oil temperature T10 by the sensor, an estimated value of the target oil temperature T10 (for example, an estimated value based on the operating state of the rotating electric machine MG or the operating state of the power transmission mechanism GT) may be used.

[0139] (4) In the above embodiment, the adjustment mechanism 211 was described as adjusting the above ratio based on at least one of the amount of oil in the oil storage section 209 (second oil amount VB) and the amount of oil in the collection section 207 (first oil amount VA) so that the amount of oil sucked by the oil pump OP is not insufficient, but it is not limited to this. The adjustment mechanism 211 may also adjust the ratio based on the amount of oil in the collection section 207 (first oil amount VA) so that the amount of oil sucked by the oil pump OP is not insufficient. Furthermore, the adjustment mechanism 211 may further adjust the ratio of the amount of oil supplied from the heat-insulating section 218 to the oil pump OP, the amount of oil supplied from the oil storage section 209 to the oil pump OP, and the amount of oil supplied from the collection section 207 (for example, the heat-insulating storage chamber 212) to the oil pump OP based on the amount of oil in the heat-insulating section 218.

[0140] (5) The configurations disclosed in each of the embodiments described above can be applied in combination with configurations disclosed in other embodiments, as long as no inconsistencies arise. With regard to other configurations, the embodiments disclosed herein are merely illustrative in all respects. Therefore, various modifications can be made as appropriate, without departing from the spirit of this disclosure.

[0141] [Outline of the Third Embodiment] The following describes the outline of the vehicle drive system (201) described above.

[0142] A vehicle drive system (201) comprising: a rotating electric machine (MG); an output member (270) driven and connected to a wheel; a power transmission mechanism (GT) that transmits power between the rotating electric machine (MG) and the output member (270); the rotating electric machine (MG), the power transmission mechanism (GT), and a case (210) containing oil; an oil storage section (209) provided at the lower part of the case (210) where the oil is stored; and an oil circuit (203) for circulating the oil, further comprising: a heat exchanger (206) that performs heat exchange between the oil flowing through the oil circuit (203) and a heat transfer medium; a waste heat utilization section (219) that utilizes the heat of the heat transfer medium; and a collection section (207) that collects the oil that has passed through the power transmission mechanism (GT), The oil circuit (203) includes a supply passage (213) for supplying the oil collected by the collection unit (207) to the heat exchanger (206), and the collection unit (207) has a structure that provides better heat insulation than the oil storage unit (209).

[0143] With this configuration, oil that has passed through the power transmission mechanism (GT) and whose temperature has risen due to the heat generated by the mechanical losses of the power transmission mechanism (GT) is collected by the collection unit (207) and sent to the heat exchanger (206) via the supply passage (213). This makes it possible to utilize the heat generated by the mechanical losses of the power transmission mechanism (GT) in the waste heat utilization unit (219). Furthermore, since the collection unit (207) has a structure with higher thermal insulation than the oil storage unit (209), it is possible to make it difficult for the heat generated by the mechanical losses of the power transmission mechanism (GT) to be transmitted elsewhere, and the efficiency of heat utilization is easily increased. Thus, with this configuration, it is possible to effectively utilize the heat generated by the mechanical losses of the power transmission mechanism (GT).

[0144] The oil circuit (203) includes a switching mechanism (208) that switches whether to collect the oil that has passed through the power transmission mechanism (GT) in the collection unit (7) and send it to the supply passage (213), or to send it to the oil storage unit (209).

[0145] With this configuration, if it is desired to prioritize oil cooling over heat utilization by the heat utilization unit (219), the switching mechanism (208) can be switched to send the oil that has passed through the power transmission mechanism (GT) to the oil storage unit (209), thereby actively dissipating heat from the oil and promoting oil cooling.

[0146] The switching mechanism (208) is configured to collect the oil in the collection unit (207) and send it to the supply passage (213) when the target oil temperature (T1), which is the temperature of the oil that has passed through the power transmission mechanism (GT), is lower than the switching threshold (Ts), and to send the oil to the oil storage unit (209) when the target oil temperature (T1) is equal to or greater than the switching threshold (Ts).

[0147] With this configuration, it is possible to appropriately determine whether to prioritize the utilization of waste heat by the waste heat utilization unit (219) or the cooling of the oil based on the temperature of the oil that has passed through the power transmission mechanism (GT), and to switch the oil flow accordingly.

[0148] The oil circuit (203) includes an oil pump (OP) that sucks and discharges oil from the oil reservoir (209) and the collection unit (207), and an adjustment mechanism (211) provided between the oil reservoir (209) and the collection unit (207) and the oil pump (OP), which adjusts the ratio between the amount of oil supplied from the oil reservoir (209) to the oil pump (OP) and the amount of oil supplied from the collection unit (207) to the oil pump (OP). The adjustment mechanism (211) adjusts the ratio based on at least one of the amount of oil in the oil reservoir (209) and the amount of oil in the collection unit (207) so that the amount of oil sucked by the oil pump (OP) is not insufficient.

[0149] This configuration reduces the possibility of the oil pump (OP) sucking in insufficient oil and consequently drawing in air, while also ensuring that at least one of the oil in the oil reservoir (209) and the collection unit (207) is properly delivered to the heat exchanger (206).

[0150] [Fourth Embodiment] An example of a vehicle drive system equipped with a vehicle drive transmission device is disclosed in Japanese Patent Application Publication No. 2024-140085. Hereinafter, the reference numerals in the said document are cited in parentheses. In the vehicle drive system (100) disclosed in this document, an oil reservoir (91) in which oil is stored is formed inside the case (9). The oil reservoir (91) includes an oil receiving section (92) and a bottom wall section (94) for receiving oil after the rotating electric machine (MG) has been cooled. The bottom wall section (94) is made of the outer wall of the case (9). The oil receiving section (92) has higher heat insulation properties than the bottom wall section (94). As a result, the heat of the oil stored in the oil receiving section (92) is less likely to be dissipated to the outside of the case (9). On the other hand, the heat from the oil stored in the bottom wall (94) is more easily dissipated to the outside of the case (9) compared to the heat from the oil stored in the oil receiving section (92). In the above-mentioned vehicle drive system (100), depending on whether or not heat recovery is necessary, the oil used to cool the rotating electric machine (MG) can be stored in the oil receiving section (92) or in the bottom wall (94). This makes it easier to improve the efficiency of oil heat utilization and the cooling efficiency of the oil.

[0151] As mentioned above, the vehicle drive system disclosed in the above-mentioned document promotes the effective use of oil after cooling the rotating electric machine, but it does not mention the effective use of oil after cooling the power transmission mechanism, and there is room for improvement in this respect.

[0152] Therefore, there is a need for a vehicle drive transmission system that can promote the efficient use of oil used to cool the power transmission mechanism.

[0153] The following describes an embodiment of a vehicle drive transmission device in view of the above, with reference to the drawings, illustrating an example of its application to a vehicle drive device. In the following description, the direction of each component refers to the direction when the vehicle drive device 400 is assembled to a vehicle (not shown) (vehicle mounted state). In the vehicle mounted state, the direction along the rotation axis A of the vehicle drive device 400 (in this embodiment, each axis is a separate axis parallel to each other (for example, the first axis A1, the second axis A2, the third axis A3, details will be described later)) is referred to as the axial direction L, with one side of the axial direction L referred to as the axial first side L1 and the other side as the axial second side L2. Furthermore, the direction perpendicular to each of the above axes is referred to as the "radial direction" with respect to each axis.

[0154] As shown in Figure 21, the vehicle drive system 400 comprises a vehicle drive transmission device 301 and a drive source 401. The drive source 401 is here defined as a rotating electric machine MG. The rotating electric machine MG is the driving force source for the vehicle. The vehicle drive transmission device 301 also comprises an input member 330 driven to the drive source, an output member 370 driven to the wheels, a power transmission mechanism GT that transmits power between the input member 330 and the output member 370, the power transmission mechanism GT, and a case 310 containing oil. The power transmission mechanism GT includes a counter gear mechanism 304 and a differential gear mechanism 305. The rotating electric machine MG includes a rotor 321. The rotor 321 is arranged on a first shaft A1. A rotor output gear 331 that rotates integrally with the rotor 321 is also arranged on the first shaft A1. The differential gear mechanism 305 is positioned on a second axis A2 that is parallel to the first axis A1 and different from the first axis A1. The counter gear mechanism 304 is positioned on a third axis A3 that is parallel to the first axis A1 and the second axis A2 and different from the first axis A1 and the second axis A2, and includes a first counter gear 341 that meshes with the rotor output gear 331, and a second counter gear 342 that rotates integrally with the first counter gear 341 and meshes with the differential input gear 351.

[0155] Here, "rotating electric machine" is used as a concept that includes motors, generators, and motor-generators that perform both motor and generator functions as needed. Furthermore, "drive connection" refers to a state in which two rotating elements are connected in a manner that can transmit driving force, and is used as a concept that includes a state in which the two rotating elements are connected so as to rotate as a whole, or a state in which the two rotating elements are connected in a manner that can transmit driving force via one or more transmission members. Such transmission members include various members that transmit rotation at the same speed or at a variable speed, such as shafts, gear mechanisms, belts, chains, etc. Also, such transmission members may include engagement devices that selectively transmit rotation and driving force, such as friction engagement devices and meshing engagement devices. The drive source 401 may be an internal combustion engine.

[0156] The rotating electric machine MG has a stator 323 fixed to a case 310 or the like, and a rotor 321 rotatably supported radially inward of the stator 323. In this embodiment, the stator 323 includes a stator core 324 and a stator coil 325 wound around the stator core 324, and the rotor 321 includes a rotor core 322 and permanent magnets (not shown) arranged on the rotor core 322. The stator coil 325 is wound around the stator core 324, and at the axial end L of the stator 323, a coil end portion 325e is formed where the bent portion of the wound stator coil 325 protrudes axially L from the stator core 324.

[0157] The rotor 321 of the rotating electric machine MG is connected to a rotor shaft 320 that rotates integrally with the rotor 321. An input member 330 is connected to the rotor shaft 320 so as to rotate integrally with the rotor shaft 320. The rotor shaft 320 is rotatably supported by the case 310 via rotor bearings, and the input member 330 is rotatably supported by the case 310 via input bearings. A rotor output gear 331 is provided on the input member 330 so as to rotate integrally with the input member 330. As will be described later, the rotor output gear 331 meshes with the first counter gear 341 of the counter gear mechanism 304.

[0158] The differential gear mechanism 305 is positioned on the second shaft A2 and distributes the driving force transmitted from the rotating electric machine MG to a pair of wheels W. In this embodiment, the differential gear mechanism 305 is composed of a plurality of bevel gears (pinion gear 353, differential output gear 354) that mesh with each other, and a differential case 352 that houses the plurality of bevel gears. The differential case 352 is connected to the differential input gear 351 so as to rotate integrally with it and supports the pinion shaft 355. The differential gear mechanism 305 transmits the rotation and torque input to the differential input gear 351 from the rotating electric machine MG to the pinion shaft 355, which is positioned along the radial direction of the second shaft A2 and rotates integrally with the differential input gear 351, and distributes and transmits it to a pair of output members 370 via a pair of differential output gears 354 that mesh with the pinion gear 353, which is rotatably supported on the pinion shaft 355. The output member 370 is connected to the wheel W, for example, via a drive shaft (not shown). In the example shown in Figure 21, the output member 370 is integrally formed with the differential output gear 354.

[0159] The counter gear mechanism 304 is positioned on the third shaft A3 and drives and connects the rotating electric machine MG and the differential gear mechanism 305 (differential input gear 351) via the rotor output gear 331. In this embodiment, the counter gear mechanism 304 is configured to have a first counter gear 341 and a second counter gear 342 connected by a counter connecting shaft 340. The first counter gear 341 meshes with the rotor output gear 331, and the second counter gear 342, connected to the first counter gear 341 by the counter connecting shaft 340, meshes with the differential input gear 351. The counter connecting shaft 340 is rotatably supported relative to the case 310. The power transmission mechanism GT may also include engagement elements such as clutches and brakes in addition to the differential gear mechanism 305 and the counter gear mechanism 304. Furthermore, the power transmission mechanism GT may not include either or both of the differential gear mechanism 305 and the counter gear mechanism 304. For example, in the case of an in-wheel motor type vehicle drive system 400, the power transmission mechanism GT does not have a differential gear mechanism 305, and the rotation of the rotating electric machine MG is transmitted to a single output member 370 (an output shaft connected to the wheel W).

[0160] As shown in Figure 22, the rotating electric machine MG is driven and controlled by the rotating electric machine control unit H2 based on the target torque of the rotating electric machine MG, which is set according to a command from the vehicle control device 600, which is a higher-level control device. The rotating electric machine control unit H2 controls the switching of an inverter circuit (inverter module) composed of multiple switching elements to convert power between DC and multi-phase (in this case, three-phase) AC in the inverter circuit. For example, the inverter circuit, including the freewheel diode, is integrated into a single power module. In addition, a DC link capacitor (not shown) is provided on the DC side of the inverter circuit as a smoothing capacitor to smooth the voltage between the positive and negative poles (DC link voltage). When the rotating electric machine MG is driven, a large current flows through the switching elements that make up the inverter circuit, causing the switching elements to heat up. For this reason, in this example, a cooling water circuit 374 is provided to cool these switching elements.

[0161] In addition, unlike the above configuration, the differential gear mechanism 305 can also be configured to be arranged coaxially with the rotating electric machine MG (i.e., on the first shaft A1). Furthermore, the power transmission mechanism GT can also be configured to include a planetary gear type transmission (e.g., a reduction gear) arranged coaxially with the rotating electric machine MG instead of the counter gear mechanism 304.

[0162] As shown in Figure 23, the vehicle drive transmission device 301 includes an oil storage section 309 located at the bottom of the case 310 where oil is stored, and a collection mechanism 307 located inside the case 310 to collect oil that has passed through the power transmission mechanism GT. In this embodiment, the vehicle drive transmission device 301 also includes an oil circuit 303 for circulating oil, a heat exchanger 306 for performing heat exchange between the oil flowing through the oil circuit 303 and a heat transfer medium, and a waste heat utilization section 319 that utilizes the heat of the heat transfer medium. In this example, an oil storage section 309 is formed at the bottom of the case 310 where oil used for lubrication and cooling falls and is stored. The oil stored in the oil storage section 309 can be supplied to at least the power transmission mechanism GT by circulating through the oil circuit 303. The oil storage section 309 is formed from the wall portion of the case 310, which is made of metal (for example, aluminum). Therefore, the heat from the oil stored in the oil reservoir 309 is easily dissipated through the outer wall of the case 310.

[0163] In this embodiment, in addition to the oil stored in the oil storage unit 309, the oil stored in the collection mechanism 307 can also be circulated through the oil circuit 303 and supplied to their respective destinations. The oil circuit 303 is configured to flow the oil stored in the oil storage unit 309 and the collection mechanism 307 to the heat exchanger 306. In this example, an oil cooler OC is used as the heat exchanger 306. The oil cooler OC is provided in the oil circuit 303 and performs heat exchange between the oil and the cooling water of the cooling water circuit 374. In other words, in this embodiment, the cooling water corresponds to the "heat transfer medium". The waste heat utilization unit 319 includes a refrigerant circuit for circulating refrigerant for the air conditioner and a heat exchange unit 350 (Figure 23). The heat exchange unit 350 is configured to perform heat exchange between the refrigerant of the refrigerant circuit and the cooling water of the cooling water circuit 374. Thus, in this embodiment, the waste heat utilization unit 319 is configured to utilize the heat of the cooling water for heating the passenger compartment. However, for example, the waste heat utilization unit 319 may be configured to utilize the heat of the cooling water for temperature control of a battery mounted in the vehicle (for example, a battery that supplies power to a rotating electric motor MG). In this case, for example, the waste heat utilization unit 319 includes a heat exchanger 306 that performs heat exchange between the refrigerant and the battery cooling water (cooling water for temperature control of the battery). Note that the heat transfer medium that exchanges heat with the oil in the heat exchanger 306 is not limited to the cooling water of the cooling water circuit 374, but may also be, for example, the refrigerant or the battery cooling water.

[0164] In this embodiment, the oil circuit 303 includes an oil pump OP that sucks and discharges oil from the oil storage section 309 and the collection mechanism 307. The oil pump OP pumps up the oil stored in the oil storage section 309 and the collection mechanism 307 and supplies the oil to the rotating electric machine MG and the power transmission mechanism GT. In this example, the oil circuit 303 is located inside the case 310 and not outside the case 310, however, a part of the oil circuit 303 may be located outside the case 310. Note that the oil pump OP is not necessarily provided, and instead of the oil pump OP, the oil may be circulated by scooping up the oil from the oil storage section 309 and the collection mechanism 307. In this example, the collection mechanism 307 includes a heat-insulating storage chamber 316 and a heat-insulating storage chamber 312. The heat-insulating storage chamber 316 and the heat-insulating storage chamber 312 are capable of storing oil that has been heated by cooling the power transmission mechanism GT.

[0165] As shown in Figure 23, the oil circuit 303 includes a first oil passage 303a (rotating electric machine circulation path) that supplies oil to the rotating electric machine MG, and a second oil passage 303b (power transmission mechanism circulation path) that branches off from the first oil passage 303a and supplies oil to the power transmission mechanism GT. In this example, the oil pumped up by the oil pump OP in the first oil passage 303a passes through the oil cooler OC and flows into the rotating electric machine MG. After cooling the rotating electric machine MG, the oil is stored in the heat-insulating storage chamber 312 (Figure 23), and then pumped up again by the oil pump OP and circulated through the first oil passage 303a. The heat-insulating storage chamber 312 has a structure that is more heat-insulating than the oil storage section 309. Therefore, the heat from the oil after cooling the rotating electric machine MG is less likely to be dissipated, which improves the efficiency of heat exchange in the heat-exhaust utilization section 319. In this example, the second oil channel 303b branches off from the first oil channel 303a upstream and merges with the first oil channel 303a downstream.

[0166] In this example, a switching solenoid valve 315 is positioned at the connection point between the first oil passage 303a and the upstream end of the second oil passage 303b (downstream of the oil cooler OC, at the branching point between the oil passage leading to the power transmission mechanism GT and the oil passage leading to the rotating electric machine MG). When the switching solenoid valve 315 is open, the oil pumped up by the oil cooler OC can enter the second oil passage 303b in addition to the oil passage leading to the rotating electric machine MG in the first oil passage 303a. The second oil passage 303b is connected to the heat-insulating storage chamber 316 downstream of the switching solenoid valve 315. In this example, as shown in Figure 23, the power transmission mechanism GT is housed in the heat-insulating storage chamber 316. The heat-insulating storage chamber 316 has a structure that provides higher heat insulation than the oil storage section 309. The second oil passage 303b is connected to the power transmission mechanism GT via a heat-insulating chamber 316 downstream of the switching solenoid valve 315. As shown in Figure 23, the heat-insulating chamber 316 can store oil that has branched off from the first oil passage 303a. This cools the power transmission mechanism GT and prevents the heat from the heated oil from being easily dissipated. Note that the heat-insulating chamber 316 does not necessarily have to be configured to store oil. Alternatively, a part of the power transmission mechanism GT may be located in the heat-insulating chamber 316.

[0167] In this example, as shown in Figure 23, both the oil used to cool the rotating electric machine MG and the oil used to lubricate and cool the power transmission mechanism GT are stored in the heat-insulating storage chamber 312. Here, the bottom of the heat-insulating storage chamber 316 is connected to the upper end of the heat-insulating storage chamber 312. The oil used to lubricate and cool the power transmission mechanism GT is configured to flow from the bottom of the heat-insulating storage chamber 316 (bottom surface 335) into the heat-insulating storage chamber 312. The heat-insulating storage chamber 316 is provided with an opening / closing mechanism 308, which will be described later. The opening / closing mechanism 308 allows the oil that has entered the heat-insulating storage chamber 316 to either flow into the heat-insulating storage chamber 312 or into the oil storage section 309 formed at the bottom of the case 310. In the illustrated example, the oil storage section 309 is located below the heat-insulating storage chamber 316. In this example, the heat-insulating storage chamber 316 and the heat-insulating storage chamber 312 are formed by separate cover members 334 and are adjacent to each other and connected. Alternatively, the heat-insulating storage chamber 316 and the heat-insulating storage chamber 312 may be integrally formed by the same cover member 334. The cover member 334 will be described later.

[0168] As shown in Figure 23, the oil circuit 303 includes a supply passage 313 that supplies oil collected by the collection mechanism 307 to the heat exchanger 306 when the outlet 302 is closed by the opening / closing mechanism 308. The oil circuit 303 also includes an adjustment mechanism 311 (here, a solenoid valve). The adjustment mechanism 311 is provided in the second oil passage 303b. In the example in Figure 23, the supply passage 313 includes an oil passage connecting the heat-insulating storage chamber 312 and the confluence point 314 where the second oil passage 303b merges with the first oil passage 303a (the point where the downstream end of the second oil passage 303b is connected to the first oil passage 303a), and an oil passage from the confluence point 314 to the oil cooler OC.

[0169] Furthermore, in the supply passage 313, a second connecting oil passage 333 is arranged parallel to the oil passage (first connecting oil passage 332) from the heat-insulating storage chamber 312 to the confluence point 314, connecting the oil storage section 309 (in this case, the bottom of the oil storage section 309) and the adjustment mechanism 311. The adjustment mechanism 311 is located in the second connecting oil passage 333. The adjustment mechanism 311 adjusts the flow rate of oil flowing from the oil storage section 309 towards the confluence point 314.

[0170] As shown in Figures 24 to 29, the collection mechanism 307 includes an outlet 302 for discharging the collected oil and an opening / closing mechanism 308 for opening and closing the outlet 302. The collection mechanism 307 is configured such that when the outlet 302 is closed by the opening / closing mechanism 308, oil is stored inside the collection mechanism 307, and when the outlet 302 is opened by the opening / closing mechanism 308, the oil inside the collection mechanism 307 is discharged to the oil storage section 309. In this example, the opening / closing mechanism 308 is located in the heat-insulated storage chamber 316 that houses the power transmission mechanism GT. The outlet 302 is formed in the heat-insulated storage chamber 316. In the example of Figure 23, when the outlet 302 is closed by the opening / closing mechanism 308, oil that enters the bottom of the heat-insulated storage chamber 316 is stored in the heat-insulated storage chamber 312 without flowing out into the oil storage section 309.

[0171] As shown in Figures 24 to 29, in this embodiment, the collection mechanism 307 includes a cover member 334 that covers a target portion B (Figure 23), which is at least a part of the power transmission mechanism GT. In this example, the cover member 334 may be configured to cover the entire power transmission mechanism GT, or to cover only a part of it. That is, the target portion B may be the entire power transmission mechanism GT, or only a part of it. In the examples of Figures 23 and 27, the cover member 334 covers a part of the power transmission mechanism GT. The heat-insulating storage chamber 316 and the heat-insulating storage chamber 312 are each formed by the cover member 334. The cover member 334 is made of a heat-insulating material such as resin, thereby giving the collection mechanism 307 higher heat insulation performance than the oil storage section 309. The cover member 334 may be made of a material with relatively low thermal conductivity, such as stainless steel. Furthermore, the components of the heat-insulating storage chamber 316 and the heat-insulating storage chamber 312 may be configured as a double-layer structure with an insulating layer such as an air layer or a vacuum layer in between, thereby providing a highly insulating structure.

[0172] The cover member 334 comprises a bottom portion 335 that covers the target portion B from below and a side portion 336 that covers the target portion B from the side. In this example, the bottom of the heat-insulating chamber 316 that houses the power transmission mechanism GT is the bottom portion 335. The side walls of the heat-insulating chamber 316 are the side portions 336. In this embodiment, an outlet 302 is provided on at least one of the bottom portion 335 and the side portion 336. In this example, an outlet 302 is provided on both the bottom portion 335 and the side portion 336. Here, the outlet 302 provided on the side portion 336 is referred to as the first outlet 302a, and the outlet 302 provided on the bottom portion 335 is referred to as the second outlet 302b. In the illustrated example, the cover member 334 is a columnar member that covers a part of the power transmission mechanism GT. Specifically, the cover member 334 constituting the heat-insulating storage chamber 316 is formed in a cylindrical shape. Furthermore, the cover member 334 constituting the heat-insulating storage chamber 316 is positioned so that the generatrix portion of the cylindrical shape is aligned with the axial direction L. Note that the position aligned with the axial direction L also includes a position that is slightly inclined with respect to the axial direction L. Therefore, the bottom portion 335 is the part that constitutes the downward-facing surface on the so-called side of the cylindrical shape. The side portion 336 is the part that constitutes the so-called bottom surface (circular bottom surface) of the cylindrical shape. Note that the side portion 336 is the side portion of the heat-insulating storage chamber 316, and the bottom portion 335 is also the bottom portion of the heat-insulating storage chamber 316.

[0173] In this example, the cover member 334 has a first through-hole S1 for inserting a shaft, such as a counter connecting shaft 340. The first through-hole S1 is formed on both of the two opposing side portions 336 that are separated in the axial direction L. When housing a part of the power transmission mechanism GT in the heat-insulating chamber 316, the shaft portion is inserted through these first through-holes S1. In the illustrated example, a second through-hole S2 is formed in the upper part of the cover member 334 that constitutes the heat-insulating chamber 316, penetrating in the vertical direction. The second through-hole S2 is formed in at least a portion of the heat-insulating chamber 316 along the axial direction L. With the second through-hole S2 formed, for example, scraped oil can enter the heat-insulating chamber 316 through the second through-hole S2. Alternatively, oil may be introduced into the heat-insulating chamber 316 from the second oil passage 303b using the second through-hole S2. Note that there may be multiple first through-holes S1. Furthermore, the size of the first through-hole S1 can be changed as appropriate. For example, in the case of a cover member 334 that covers the entire power transmission mechanism GT, it is preferable that the first through-hole S1 is sized to allow multiple shafts along the first shaft A1, second shaft A2, and third shaft A3 to be inserted through it. It is also preferable that multiple first through-holes S1 through which these shafts can be inserted are formed. Furthermore, the size and shape of the cover member 334 can be changed as appropriate depending on the size and arrangement of the gears and other components to be housed inside.

[0174] In this embodiment, at least one of the bottom portion 335 and the side portion 336 of the cover member 334 is provided with a fixed member 337 whose position relative to the case 310 is fixed, and a movable member 338 which is arranged to overlap with the fixed member 337. In this example, the bottom portion 335 and the side portion 336 each have a fixed member 337 and a movable member 338. As shown in Figures 24 and 25, outlets 302 (first outlet 302a, second outlet 302b) are formed on both the side portion 336 and the bottom portion 335. A plurality of movable members 338 are arranged to correspond to each outlet 302. Here, the first outlet 302a is formed on one side of two opposing side portions 336 which are arranged in the axial direction L. In this example, the position of the entire cover member 334, excluding the movable members 338, is fixed relative to the case 310. Therefore, with respect to the movable member 338 provided corresponding to the first discharge port 302a formed on the side portion 336, the side portion 336 becomes the fixed member 337. Similarly, with respect to the movable member 338 provided corresponding to the second discharge port 302b provided on the bottom portion 335, the bottom portion 335 becomes the fixed member 337. Alternatively, the fixed member 337 for each movable member 338 may be the portion of the cover member 334 excluding the movable member 338. Thus, in this embodiment, the discharge port 302 is formed on the fixed member 337.

[0175] In this embodiment, the movable member 338 is provided with an opening 344. The opening / closing mechanism 308 includes the movable member 338 and a drive device 360 ​​that moves the movable member 338 to a first position P1 and a second position P2. The movable member 338 is supported so as to be able to move relative to the fixed member 337, and the movable member 338 is configured to close the discharge port 302 when it is in the first position P1, and to open the discharge port 302 when the opening 344 overlaps with the discharge port 302 when it is in the second position P2. In the following, the direction perpendicular to the axial direction L in the cover member 334 will be referred to as the radial direction R.

[0176] As shown in Figure 24, multiple first outlets 302a are formed on the side portion 336. Here, as described above, the side portion 336 is formed in a circular shape. The first through hole S1 is formed in the center of the side portion 336. As a result, the side portion 336 is formed in an annular shape when viewed in the axial direction L. The multiple first outlets 302a penetrate the side portion 336 in the axial direction L. These first outlets 302a are positioned radially outward from the first through hole S1. Furthermore, these first outlets 302a are arranged with spacing between them in the circumferential direction C (hereinafter simply referred to as circumferential direction C) with respect to the rotation axis A. On the other hand, the first outlets 302a are not positioned above the first through hole S1.

[0177] Multiple movable members 338 corresponding to the first discharge ports 302a are provided so as to be slidable relative to the fixed member 337 (in this case, the side portion 336). In this example, the movable members 338 are attached to the fixed member 337 from the outside in the axial direction L, that is, from outside the heat-insulating storage chamber 316. In the illustrated example, the fixed member 337 is provided with a guide member 346 that supports the movable members 338 so as to be slidable in the circumferential direction C. Therefore, the movable members 338 are provided on the fixed member 337 via the guide member 346.

[0178] The movable member 338 is provided with a plurality of openings 344 corresponding to each of the plurality of outlets 302 (here, the first outlet 302a) arranged in the circumferential direction C. The plurality of openings 344 are arranged in the movable member 338 with spacing between them in the circumferential direction C. The openings 344 are formed to penetrate the movable member 338 in the axial direction L. In the example of Figure 24, the spacing between the openings 344 arranged in the circumferential direction C is greater than the spacing between the outlets 302 (here, the first outlet 302a) arranged in the circumferential direction C. At the first position P1, each first outlet 302a overlaps with the movable member 338 (more specifically, the region between the two openings 344 in the circumferential direction C) in the axial direction L. As a result, the first outlets 302a at the first position P1 are completely covered by the movable member 338 from the outside in the axial direction L. Therefore, it is possible to prevent oil in the heat-insulating storage chamber 316 from flowing out to the outside and accumulating in the oil storage section 309.

[0179] In contrast, at the second position P2, each of the multiple first outlets 302a overlaps with the corresponding opening 344 of the movable member 338 in an axial view L. As a result, each first outlet 302a is opened, and the oil in the heat-insulating storage chamber 316 flows out of the heat-insulating storage chamber 316 through the opening 344 formed in the side portion 336 and can be stored in the oil storage section 309 (Figure 23). In the illustrated example, the sizes of the first outlets 302a and the openings 344 are approximately the same, but for example, the opening 344 may be formed to be smaller than the first outlets 302a.

[0180] In this example, the movable member 338 is a plate-shaped member. In the illustrated example, the movable member 338 is a long, plate-shaped member that extends along the circumferential direction C and also along the radial direction R. The movable member 338 is supported from both sides in the radial direction R by a pair of guide members 346 (here, members that function as guide rails). The pair of guide members 346 are spaced apart in the radial direction R and support the movable member 338 so that it can slide in the circumferential direction C. In the example of Figure 24, the pair of guide members 346 are fixed to the surface of the side portion 336 facing outward in the axial direction L, corresponding to the movable member 338 which is positioned outward in the axial direction L relative to the side portion 336.

[0181] As shown in Figure 24, the drive device 360 ​​includes a link mechanism 366 connected to the movable member 338 and a drive source (not shown), such as an electric motor, that drives the link mechanism 366. The movable member 338 slides between a first position P1 and a second position P2 due to the operation of the link mechanism 366. Note that the drive device 360 ​​in Figure 24 is just one example, and the configuration of the drive device 360 ​​can be changed as appropriate as long as the movable member 338 is moved as described above. In this embodiment, the drive device 360 ​​is located outside the heat-insulating storage chamber 316. In the illustrated example, the drive device 360 ​​is located below the cover member 334 that constitutes the heat-insulating storage chamber 316.

[0182] The configuration of the opening / closing mechanism 308 for the second outlet 302b in the bottom portion 335 is basically the same as the configuration of the opening / closing mechanism 308 for the first outlet 302a described above. Therefore, this section will focus on explaining the differences in the configuration of the opening / closing mechanism 308. As shown in Figure 25, the second outlet 302b is formed to penetrate the bottom portion 335 in the vertical direction. In the example of Figure 25, a single second outlet 302b is provided, but multiple second outlets 302b may be arranged in a line, for example, along the axial direction L, or multiple second outlets 302b may be arranged in a line along the circumferential direction C. The size and number of second outlets 302b can be appropriately changed according to the size of the heat-insulating storage chamber 316.

[0183] The movable member 338 corresponding to the second outlet 302b has the same number of openings 344 as the number of second outlets 302b. In the example of Figure 25, the movable member 338 has a single opening 344. Here, the movable member 338 is a long, plate-shaped member that extends along the circumferential direction C and along the axial direction L. In the illustrated example, the size of the opening 344 corresponding to the second outlet 302b is smaller than the second outlet 302b, but they may be of similar size. The movable member 338 is supported so as to be slidable in the circumferential direction C by a pair of guide members 346 (omitted in Figure 25) arranged separately in the axial direction L. When the movable member 338 slides to the second position P2, the second outlet 302b and the opening 344 overlap in the vertical direction. As a result, the oil in the heat-insulating storage chamber 316 flows out into the oil storage section 309 (Figure 23). Furthermore, as the movable member 338 slides to the first position P1, the second discharge port 302b and the plate-shaped portion of the movable member 338 overlap in the vertical direction. As a result, the oil in the heat-insulating storage chamber 316 is prevented from flowing out into the oil storage section 309.

[0184] In the example shown in Figure 26, the bottom portion 335 is provided with a plurality (in this case, a pair) of locking members 372 for locking the side portion 336. The pair of locking members 372 are arranged at the axial end L of the bottom portion 335, spaced apart in the axial direction L. The lower end portion of the side portion 336 is positioned between the pair of locking members 372 in the axial direction L. This locks the side portion 336 to the bottom portion 335. In the illustrated example, an oil seal 359 is also positioned between the pair of locking members 372. This supports the side portion 336 to the bottom portion 335 via the oil seal 359. The movable member 338 is locked to the side portion 336 by a pair of guide members 346. Note that, as shown in another example enclosed by a dashed line in Figure 26, the locking members 372 may be integrally formed with the guide members 346.

[0185] As shown in Figures 27 and 28, when the movable member 338 is positioned inside the side portion 336 and the bottom portion 335 (inside the cover member 334), the pair of guide members 346 are also positioned inside the side portion 336 and the bottom portion 335. The basic configuration of the opening / closing mechanism 308 in this case is the same as that of the opening / closing mechanism 308 described in Figures 24 and 25. Therefore, this section will focus on describing the differences in the configuration of the opening / closing mechanism 308. Here, the link mechanism 366 of the drive device 360 ​​is connected to the movable member 338 positioned inside the cover member 334 via the discharge port 302 (first discharge port 302a, second discharge port 302b). The movable member 338 slides between the first position P1 and the second position P2 due to the operation of the link mechanism 366. In the example shown in Figure 27, the first outlet 302a, to which the link mechanism 366 and the movable member 338 are connected, has a connecting opening 345 that is larger in the circumferential direction C than the other outlets 302, so that it can slide appropriately between the first position P1 and the second position P2.

[0186] In the example shown in Figure 29, a pair of guide members 346 are provided on the inside of the side portion 336 in the axial direction L (on the inside side of the heat-insulating storage chamber 316). Also, as in the example shown in Figure 26, the pair of guide members 346 and the locking member 372 are provided as separate components. On the other hand, as shown in the alternative example enclosed by the dashed line in Figure 29, the locking member 372 may be integrally formed with the guide members 346 provided on the inside of the side portion 336 in the axial direction L.

[0187] In this embodiment, the vehicle drive unit 400 further includes an oil circuit control unit H1 (Figure 22) that can communicate with the vehicle control device 600. The functions of the oil circuit control unit H1 are realized through the cooperation of hardware such as a microcomputer and software (program). The functions of the oil circuit control unit H1 are realized through the cooperation of hardware such as a microcomputer and software (program). The oil circuit control unit H1 controls the opening and closing mechanism 308 described above. In this example, the oil circuit control unit H1 also controls the adjustment mechanism 311 and the switching solenoid valve 315, etc., located in the oil circuit 303.

[0188] The oil circuit control unit H1 controls the drive device 360 ​​of the opening / closing mechanism 308 to slide the movable member 338 between a first position P1 and a second position P2. In this example, a temperature sensor Se is provided inside the cover member 334, more specifically in the heat-insulating storage chamber 312 (Figure 23). The oil circuit control unit H1 also includes a temperature monitoring unit (not shown) that monitors the temperature detected by the temperature sensor Se. In this way, the oil circuit control unit H1 detects the temperature of the oil stored in the heat-insulating storage chamber 312. Then, as shown in Figure 30, when the oil circuit control unit H1 determines, based on the temperature monitoring unit, that the temperature T of the oil stored in the heat-insulating storage chamber 312 is equal to or greater than the specified temperature T1 (T≧T1) (S01: Yes), it controls the opening / closing mechanism 308 (in this case, the drive unit 360) to move the movable member 338 to the second position P2, thereby opening the discharge port 302 (first discharge port 302a, second discharge port 302b) (S02). As a result, the oil that has been heated by cooling the power transmission mechanism GT flows out of the heat-insulating storage chamber 316 through the discharge port 302 and is stored in the oil storage section 309. On the other hand, if the oil circuit control unit H1 determines, based on the temperature monitoring unit, that the temperature T of the oil stored in the heat-insulating storage chamber 312 is less than the specified temperature T1 (T < T1) (S01: No), it controls the opening / closing mechanism 308 to move the movable member 338 to the first position P1, thereby closing the discharge port 302 (first discharge port 302a, second discharge port 302b) (S03). As a result, the oil that has been heated by cooling the power transmission mechanism GT flows from the bottom surface 335 of the heat-insulating storage chamber 316 to the heat-insulating storage chamber 312 and is stored in the heat-insulating storage chamber 312. Here, it is preferable that the specified temperature T1 is set to a value smaller than the temperature at which oil overheating may occur. Note that the temperature sensor Se may be provided in the heat-insulating storage chamber 316.

[0189] Furthermore, in this example, the drive unit 360 may be configured to include a temperature-sensitive actuator. For example, the drive unit 360 may be configured to include a spring, thermostat, etc., that pushes or pulls the link mechanism 366 in response to temperature changes detected by the temperature sensor Se. In that case, the drive unit 360 does not need to include an electric motor or the like. Thus, the configuration of the drive unit 360 can be changed as appropriate. Of course, the drive unit 360 may also include an electric actuator.

[0190] [Other Embodiments of the Fourth Embodiment] (1) In the above embodiment, the configuration in which the oil after cooling the power transmission mechanism GT flows from the heat-insulating storage chamber 316 into the heat-insulating storage chamber 312 and is stored was described as an example, but the invention is not limited to this. The oil after cooling the power transmission mechanism GT can also be stored at the bottom surface portion 335 of the heat-insulating storage chamber 316. Alternatively, the power transmission mechanism GT can be configured to scoop up the oil stored in the heat-insulating storage chamber 316. Thus, the configuration of the heat-insulating storage chamber 316 can be changed as appropriate.

[0191] (2) In the above embodiment, a configuration in which the discharge port 302 is provided on both the bottom portion 335 and the side portion 336 was described as an example, but the invention is not limited thereto. For example, a configuration in which the discharge port 302 is provided only on the bottom portion 335 is possible. Similarly, a configuration in which the discharge port 302 is provided only on the side portion 336 is possible. For example, if the side portion 336 that forms the heat-insulating storage chamber 316 covers about the lower half of the power transmission mechanism GT, and the upper part is open, then the discharge port 302 may not be provided on the side portion 336, and the discharge port 302 may be provided on the bottom portion 335.

[0192] (3) In the above embodiment, a configuration was described as in which the outlet 302 is closed at a first position P1 and opened at a second position P2 as the movable member 338 slides along the circumferential direction C, but the invention is not limited to this. For example, a thermostat valve that opens and closes at a set temperature (for example, a specified temperature T1) may be provided at the outlet 302. Then, the thermostat valve is opened when the temperature is above the specified temperature T1, thereby opening the outlet 302, and the thermostat valve is closed when the temperature is below the specified temperature T1, thereby closing the outlet 302.

[0193] (4) In the above embodiment, the supply passage 313 was described as including an oil passage connecting the heat-insulating storage chamber 312 and the confluence point 314 where the second oil passage 303b merges with the first oil passage 303a (the point where the downstream end of the second oil passage 303b is connected to the first oil passage 303a), and an oil passage from the confluence point 314 to the oil cooler OC, but the configuration is not limited to this. The supply passage 313 may further include an oil passage from the oil cooler OC to the switching solenoid valve 315.

[0194] (5) The configurations disclosed in each of the embodiments described above can be applied in combination with configurations disclosed in other embodiments, as long as no inconsistencies arise. With regard to other configurations, the embodiments disclosed herein are merely illustrative in all respects. Therefore, various modifications can be made as appropriate, without departing from the spirit of this disclosure.

[0195] [Outline of the Fourth Embodiment] The following describes the outline of the vehicle drive transmission device (301) described above.

[0196] A vehicle drive transmission device (301) comprising: an input member driven to a drive source (401); an output member (370) driven to a wheel; a power transmission mechanism (GT) that transmits power between the input member and the output member (370); the power transmission mechanism (GT); and a case (310) containing oil, wherein the case (310) comprises: an oil storage section (309) provided at the lower part of the case (310) for storing the oil; and a collection mechanism (307) disposed inside the case (310) for collecting the oil that has passed through the power transmission mechanism (GT), wherein the collection mechanism (307) comprises: an outlet (302) for discharging the collected oil; and an opening / closing mechanism (308) for opening and closing the outlet (302). When the outlet (302) is closed by the opening / closing mechanism (308), the oil is stored in the collection mechanism (307), and when the outlet (302) is opened by the opening / closing mechanism (308), the oil in the collection mechanism (307) is discharged to the oil storage section (309).

[0197] With this configuration, when the outlet (302) is closed by the opening / closing mechanism (308), the oil that has passed through the power transmission mechanism (GT) and whose temperature has risen due to the heat generated by the mechanical losses of the power transmission mechanism (GT) can be collected by the collection mechanism (307). As a result, compared to a configuration in which the oil that has passed through the power transmission mechanism (GT) is discharged to the oil reservoir (309) at the bottom of the case (310), the heat from the oil is less likely to be released to the outside through the case (310). Therefore, it becomes easier to increase the efficiency of utilizing the heat of the oil, and when the ambient temperature is low, it becomes possible to reduce the viscosity of the oil earlier and reduce the mechanical losses of the power transmission mechanism (GT) earlier. On the other hand, when the outlet (302) is open by the opening / closing mechanism (308), the oil that has passed through the power transmission mechanism (GT) is discharged to the oil reservoir (309), so the heat from the oil is more easily released to the outside through the case (310). Therefore, when the oil temperature is high, it becomes easier to cool the oil. Thus, this configuration makes it possible to promote the efficient use of the oil used to cool the power transmission mechanism (GT).

[0198] The collection mechanism (307) includes a cover member (334) that covers a target portion (B) which is at least a part of the power transmission mechanism (GT), the cover member (334) includes a bottom portion (335) that covers the target portion (B) from below and a side portion (336) that covers the target portion (B) from the side, and the discharge port (302) is provided on at least one of the bottom portion (335) and the side portion (336).

[0199] With this configuration, when the outlet (302) is closed by the opening / closing mechanism (308), the oil that has passed through the power transmission mechanism (GT) can be properly collected and stored by the cover member (334). Since the outlet (302) is provided on at least one of the bottom surface (335) and side surface (336) of the cover member (334), when the outlet (302) is opened by the opening / closing mechanism (308), the oil stored in the collection mechanism (307) can be properly discharged to the oil storage section (309).

[0200] At least one of the bottom portion (335) and the side portion (336) of the cover member (334) comprises a fixed member (337) whose position is fixed relative to the case (310) and a movable member (338) arranged to overlap with the fixed member (337), wherein the movable member (338) is supported so as to be able to move relative to the fixed member (337), the discharge port (302) is formed in the fixed member (337), the movable member (338) comprises an opening (344), and the opening / closing mechanism (308) includes the movable member (338) and a drive device (360) for moving the movable member (338) to a first position (P1) and a second position (P2). The movable member (338) is configured to close the discharge port (302) when in the first position (P1), and to open the discharge port (302) when in the second position (P2) by having its opening (344) overlap with the discharge port (302).

[0201] With this configuration, when the movable member (338) is in the first position (P1), the discharge port (302) is closed, so that the oil can be properly collected and stored by the cover member (334). When the movable member (338) is in the second position (P2), the discharge port (302) is opened, so that the oil can be properly discharged from the cover member (334) to the oil storage section (309). In this way, by moving the movable member (338) between the first position (P1) and the second position (P2), the discharge port (302) can be switched between an open state and a closed state. Therefore, a relatively simple opening / closing mechanism (308) and cover member (334) can be realized.

[0202] The system comprises an oil circuit (303) for circulating the oil, a heat exchanger (306) for performing heat exchange between the oil flowing through the oil circuit (303) and a heat transfer medium, and a waste heat utilization unit (319) for utilizing the heat of the heat transfer medium. The oil circuit (303) includes a supply passage (313) for supplying oil collected by the collection mechanism (307) to the heat exchanger (306) when the outlet (302) is closed by the opening / closing mechanism (308).

[0203] With this configuration, the discharge port (302) is closed by the opening / closing mechanism (308), and the oil that has passed through the power transmission mechanism (GT) and whose temperature has risen due to the heat generated by the mechanical losses of the power transmission mechanism (GT) is collected by the collection mechanism (307), and the collected oil can be sent to the heat exchanger (306) via the supply passage (313). This makes it possible to utilize the heat generated by the mechanical losses of the power transmission mechanism (GT) in the waste heat utilization section (319).

[0204] 1: Vehicle drive unit, 2: Rotating electric machine, 3: Power transmission mechanism, 4: Wheel, 5: Control unit, 6: Oil pump, 7: Oil circuit, 8: Oil cooler (heat exchanger), 9: Case, 33: Output component, 71: First supply path, 72: Second supply path, 80: Heat transfer medium, LFmg: Motor load factor (load of rotating electric machine), Tlf: Load threshold, Tmg: Motor temperature (temperature of rotating electric machine), Toil: Oil temperature (temperature of oil), Tt: Temperature threshold, VX: First control valve, V Y: Second control valve, 101: Vehicle drive unit, 102: Rotating electric machine, 103: Power transmission mechanism, 104: Wheel, 107: Oil passage, 109: Case, 121: Rotor, 122: Stator, 123: Stator core, 124: Stator coil (coil), 125: Stator cover, 133: Output component, 161: Oil pump, 162: Oil cooler (heat exchanger), 171: First circulation path, 172: Second circulation path, 173: Oil passage inside cover, 179: Oil reservoir, V: valve (switching device), V1: first valve (switching device), V2: second valve (switching device) 201: vehicle drive unit, 203: oil circuit, 206: heat exchanger, 207: collection unit, 208: switching mechanism, 209: oil reservoir, 210: case, 211: adjustment mechanism, 213: supply line, 219: waste heat utilization unit, 270: output member, GT: power transmission mechanism, MG: rotating electric machine, OP: oil pump, T10: target oil temperature, Ts: switching threshold, 301: vehicle drive unit Power transmission device, 302: Outlet, 303: Oil circuit, 306: Heat exchanger, 307: Collection mechanism, 308: Opening / closing mechanism, 309: Oil reservoir, 310: Case, 313: Supply path, 319: Exhaust heat utilization section, 334: Cover member, 335: Bottom part, 336: Side part, 337: Fixing member, 338: Movable member, 344: Opening, 360: Drive device, 370: Output member, 401: Drive source, B: Target part, GT: Power transmission mechanism, P1: First position, P2: Second position

Claims

1. A vehicle drive system comprising: a rotating electric machine; an output member driven to a wheel; a power transmission mechanism for transmitting power between the rotating electric machine and the output member; a case containing oil, the rotating electric machine, the power transmission mechanism, and oil; an oil pump for drawing in and discharging the oil; and an oil circuit through which the oil discharged from the oil pump circulates, wherein the oil circuit comprises: a first supply path for supplying the oil discharged from the oil pump to the rotating electric machine; a second supply path for supplying the oil discharged from the oil pump to the power transmission mechanism; a first control valve for switching the first supply path between an open state and a closed state; and a second control valve for switching the second supply path between an open state and a closed state, wherein when the first control valve is closed, the supply of oil from the oil pump to the rotating electric machine is cut off; and when the second control valve is closed, the supply of oil from the oil pump to the power transmission mechanism is cut off.

2. A vehicle drive device according to claim 1, comprising a control unit for controlling the oil pump, the first control valve, and the second control valve, wherein the oil circuit comprises a heat exchanger for exchanging heat between the oil and a heat transfer medium, the control unit performs a heat utilization mode in which the oil pump, the first control valve, and the second control valve perform operations for utilizing the heat of the heat transfer medium in the vehicle, and a general mode other than the heat utilization mode, the control unit, in the general mode, when the vehicle is running and the temperature of the rotating electric machine is below a preset temperature threshold and the load of the rotating electric machine is below a preset load threshold, shuts off the first control valve and opens the second control valve, and in the general mode, when the vehicle is running and the temperature of the rotating electric machine is above the temperature threshold, or the load of the rotating electric machine is above the load threshold, opens both the first control valve and the second control valve.

3. The vehicle drive device according to claim 2, wherein the control unit, in the general mode, increases the amount of oil discharged by the oil pump in accordance with the temperature of the oil and the temperature of the rotating electric machine, and increases the amount of oil discharged by the oil pump in accordance with the temperature of the rotating electric machine.

4. A vehicle drive device according to claim 1, comprising: an oil pump, a first control valve, and a second control valve; the oil circuit comprising a heat exchanger for exchanging heat between the oil and a heat transfer medium; the control unit performing a heat utilization mode in which the oil pump, the first control valve, and the second control valve perform operations for utilizing the heat of the heat transfer medium in the vehicle; and a general mode other than the heat utilization mode; the control unit comprising a stationary heat generation mode performed when the vehicle is not running and a waste heat recovery mode performed when the vehicle is running; the control unit, in the stationary heat generation mode, sets the first control valve to a connected state and the second control valve to a closed state; and in the waste heat recovery mode, sets both the first control valve and the second control valve to a connected state.

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