OIL PAN AND VEHICLE DRIVE DEVICE INCLUDING THE SAME

Abstract

An oil pan for use in a vehicle drive device includes a drive source and a case accommodating the drive source and oil, the oil pan including: an opposing inner surface constituting an oil reservoir formed inside the case; an outer surface facing an exterior of the case; a heat medium layer formed between the opposing inner surface and the outer surface, through which a liquid heat medium flows; an inlet through which the liquid heat medium flows into the heat medium layer; and an outlet through which the liquid heat medium flows out of the heat medium layer, in which the heat medium layer is disposed to cover the opposing inner surface from the outer surface side.

Description

CROSS REFERENCE TO RELATED APPLICATIONS

This application is based on and claims priority under 35 U.S.C. § 119 to Japanese Patent Application No. 2025-034480, filed on Mar. 5, 2025, the entire content of which is incorporated herein by reference.

TECHNICAL FIELD

The present disclosure relates to an oil pan and a vehicle drive device including the oil pan.

BACKGROUND DISCUSSION

JP 2019-108803 A described below discloses an oil pan (1) used in a vehicle drive device. A heat insulation layer (6) is formed in the oil pan (1). In the description of the background art, reference numerals in parentheses are those in JP 2019-108803 A.

In the oil pan (1), heat retention performance is enhanced by the heat insulation layer (6) to reduce a decrease in the temperature of the oil in the oil reservoir. However, there is a case where it is desired to lower the temperature of the oil depending on the outside air temperature and the state of the vehicle drive device.

A need thus exists for an oil pan which is not susceptible to the drawback mentioned above.

SUMMARY

An oil pan for use in a vehicle drive device including a drive source and a case accommodating the drive source and oil, the oil pan includes:

an opposing inner surface constituting an oil reservoir formed inside the case;

an outer surface facing an exterior of the case;

a heat medium layer formed between the opposing inner surface and the outer surface, through which a liquid heat medium flows;

an inlet through which the liquid heat medium flows into the heat medium layer; and

an outlet through which the liquid heat medium flows out of the heat medium layer, in which

the heat medium layer is disposed to cover the opposing inner surface from the outer surface side.

BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing and additional features and characteristics of this disclosure will become more apparent from the following detailed description considered with the reference to the accompanying drawings, wherein:

FIG. 1 is a view illustrating a vehicle drive device according to an embodiment;

FIG. 2 is a side sectional view of an oil pan according to the embodiment;

FIG. 3 is a plan sectional view of the oil pan according to the embodiment;

FIG. 4 is a view illustrating a heat medium control device in a flowing state; and

FIG. 5 is a view illustrating the heat medium control device in a sealed state.

DETAILED DESCRIPTION

Hereinafter, an oil pan 10 according to an embodiment and a vehicle drive device 100 including the oil pan will be described with reference to the drawings.

As illustrated in FIG. 1, the vehicle drive device 100 includes a drive source DS and a case CS. In the present embodiment, the vehicle drive device 100 further includes an inverter INV.

The drive source DS is configured to generate a drive force for rotating a wheel W. In the present embodiment, the drive source DS is a rotary electric machine having a function as a motor (electric motor) that receives electric power supply and generates driving power and a function as a generator (alternator) that receives driving power supply and generates electric power. Therefore, the drive source DS is electrically connected to a battery BT provided in the vehicle. Then, the drive source DS generates a drive force by performing powering operation using the electric power stored in the battery BT. In addition, the drive source DS performs power generation by the drive force transmitted from the wheel W side to charge the battery BT.

The drive source DS constitutes a part of a drive unit DU. In the present embodiment, the drive unit DU includes a transmission TM and a differential gear mechanism DF in addition to the drive source DS.

The transmission TM is configured to shift the rotation of the drive source DS and transmit the rotation to the differential gear mechanism DF. The differential gear mechanism DF is configured to distribute the rotation transmitted from the transmission TM to a pair of the wheels W.

The inverter INV is configured to control the drive source DS as the rotary electric machine.

The case CS accommodates the drive source DS and oil F (see FIG. 2). In the present embodiment, the case CS further accommodates the transmission TM, the differential gear mechanism DF, and the inverter INV.

As illustrated in FIG. 2, an oil reservoir ST that stores the oil F is formed inside the case CS. The oil reservoir ST is formed by the oil pan 10. In the present embodiment, the oil pan 10 constitutes a part of the case CS.

As illustrated in FIGS. 2 and 3, the oil pan 10 includes an opposing inner surface 1, an outer surface 2, a heat medium layer 3, an inlet 4, and an outlet 5. In the present embodiment, the oil pan 10 further includes a heat insulation layer 6.

The opposing inner surface 1 is a surface constituting the oil reservoir ST. At least a part of the inner surface of the oil pan 10, facing the inside of the case CS, is formed as the opposing inner surface 1. In the present embodiment, the opposing inner surface 1 includes a first inner surface 11 facing upward and a second inner surface 12 formed over the entire circumference of the first inner surface 11 so as to rise upward from the first inner surface 11.

The outer surface 2 is a surface facing the exterior of the case CS. In the present embodiment, the outer surface 2 includes a first outer surface 21 facing downward and a second outer surface 22 formed over the entire circumference of the first outer surface 21 so as to rise upward from the first outer surface 21. The first outer surface 21 is disposed to cover the first inner surface 11 from below (see FIG. 2). The second outer surface 22 is disposed to cover the second inner surface 12 from the outside (see FIG. 3).

The heat medium layer 3 is configured such that a liquid heat medium H flows. The heat medium layer 3 functions as a heat retention state adjustment layer that changes the heat retention state of the oil F in the oil reservoir ST depending on a flow state of the liquid heat medium H.

The heat medium layer 3 is formed between the opposing inner surface 1 and the outer surface 2. The heat medium layer 3 is disposed to cover the opposing inner surface 1 from the outer surface 2 side. In the present embodiment, the heat medium layer 3 is disposed to cover the first inner surface 11 from the first outer surface 21 side and to cover the second inner surface 12 from the second outer surface 22 side. The heat medium layer 3 is formed continuously without a gap. Note that the heat medium layer 3 may be formed of flow channels arranged in a mesh pattern or flow channels arranged in a serpentine pattern.

The liquid heat medium H is a liquid heat medium that flows through the heat medium layer 3. As the liquid heat medium H, a liquid having a larger heat capacity than that of water, such as a long-life coolant (LLC), is preferably used. As the liquid heat medium H, a refrigerant for an air conditioner, or the like may be used.

The inlet 4 is a flow channel through which the liquid heat medium H flows into the heat medium layer 3. The outlet 5 is a flow channel through which the liquid heat medium H flows out of the heat medium layer 3. Each of the inlet 4 and the outlet 5 is configured to communicate the flow channel of the liquid heat medium H disposed inside the case CS with the heat medium layer 3.

The heat insulation layer 6 is configured to inhibit heat transfer between the opposing inner surface 1 and the outer surface 2. The heat insulation layer 6 includes: a gas layer in which a gas (e.g., air, argon, krypton) having a relatively low thermal conductivity is sealed; a thermal insulation material layer in which a thermal insulation material (e.g., glass wool, rock wool, polystyrene foam, rigid urethane foam) having a relatively low thermal conductivity is sealed; and a vacuum layer in a vacuum state.

The heat insulation layer 6 is formed between the heat medium layer 3 and the outer surface 2. The heat insulation layer 6 is disposed to cover the heat medium layer 3 from the outer surface 2 side. In the present embodiment, the heat insulation layer 6 is disposed to cover the heat medium layer 3 from the first outer surface 21 side and to cover the heat medium layer 3 from the second outer surface 22 side. The heat insulation layer 6 is formed continuously without a gap. Note that the heat insulation layer 6 may be formed of voids arranged in a mesh pattern or voids arranged in a serpentine pattern.

In the present embodiment, the oil pan 10 includes a first body portion 10A in which the opposing inner surface 1 is formed and a second body portion 10B in which the outer surface 2 is formed.

The first body portion 10A is formed of a metal such as an iron alloy or an aluminum alloy. The first body portion 10A includes a layer-forming outer surface 7 in addition to the opposing inner surface 1.

The layer-forming outer surface 7 includes a first forming surface 71 facing downward and a second forming surface 72 formed over the entire circumference of the first forming surface 71 so as to rise upward from the first forming surface 71. The first forming surface 71 is disposed to cover the first inner surface 11 from below (see FIG. 2). The second forming surface 72 is disposed to cover the second inner surface 12 from the outside (see FIG. 3).

The second body portion 10B is formed of a synthetic resin having a lower thermal conductivity than that of the metal constituting the first body portion 10A.

The second body portion 10B is formed to cover the first body portion 10A from below. The second body portion 10B is fixed to the first body portion 10A with a fixing member such as a bolt. The second body portion 10B includes a layer-forming inner surface 8 in addition to the outer surface 2.

The layer-forming inner surface 8 includes a third forming surface 81 facing upward and a fourth forming surface 82 formed over the entire circumference of the third forming surface 81 so as to rise upward from the third forming surface 81. The third forming surface 81 is disposed to face the first forming surface 71 and to cover the first outer surface 21 from above (see FIG. 2). The fourth forming surface 82 is disposed to face the second forming surface 72 and to cover the second outer surface 22 from the inside (see FIG. 3).

In the present embodiment, the heat medium layer 3 includes a space between the layer-forming outer surface 7 of the first body portion 10A and the layer-forming inner surface 8 of the second body portion 10B. More specifically, the heat medium layer 3 includes a space formed between the first forming surface 71 and the third forming surface 81, and a space formed between the second forming surface 72 and the fourth forming surface 82.

In the present embodiment, the heat insulation layer 6 includes a space between the outer surface 2 of the second body portion 10B and the layer-forming inner surface 8. More specifically, the heat insulation layer 6 includes a space formed between the first outer surface 21 and the third forming surface 81, and a space formed between the second outer surface 22 and the fourth forming surface 82.

In the present embodiment, the inlet 4 and the outlet 5 are formed in the first body portion 10A so as to open upward.

In the present embodiment, the vehicle drive device 100 further includes a heat medium control device 9 that controls the flow state of the liquid heat medium H, as illustrated in FIGS. 4 and 5. The heat medium control device 9 is configured to allow the flow state to be changed between a sealed state in which, while the heat medium layer 3 is filled with the liquid heat medium H, the flow of the liquid heat medium H is stopped, and a flowing state in which the liquid heat medium H is caused to flow from the inlet 4 toward the outlet 5 in the heat medium layer 3.

The heat medium control device 9 includes a heat medium pump 91, a heat medium circuit 92, a control valve 93, a first heat exchange unit 94, and a second heat exchange unit 95. In the present embodiment, the heat medium control device 9 further includes a third heat exchange unit 96, an oil pump 97, and an oil circuit 98.

The heat medium pump 91 is a pump that sucks and discharges the liquid heat medium H. The heat medium circuit 92 is a circuit through which the liquid heat medium H discharged by the heat medium pump 91 circulates. The control valve 93 is a valve that switches the flow state of the liquid heat medium H in the heat medium circuit 92. In the present embodiment, the control valve 93 includes a first valve 931 and a second valve 932. Each of the first valve 931 and the second valve 932 is a three-way valve.

The first heat exchange unit 94 is configured to perform heat exchange between the liquid heat medium H and the outside air. In the present embodiment, the first heat exchange unit 94 includes a radiator 941 that dissipates the heat of the liquid heat medium H to the outside of the vehicle.

The second heat exchange unit 95 is configured to perform heat exchange for using the heat of the liquid heat medium H on the vehicle side. In the present embodiment, the second heat exchange unit 95 includes a refrigerant circuit RC (more specifically, a flow channel that is provided adjacent to the refrigerant circuit RC to exchange heat with a refrigerant flowing through the refrigerant circuit RC, the refrigerant being for an air conditioner provided in the vehicle) through which the refrigerant flows. The second heat exchange unit 95 includes the battery BT (more specifically, a flow channel that is provided adjacent to the battery BT to exchange heat with the battery BT).

The third heat exchange unit 96 is configured to perform heat exchange between the liquid heat medium H and the oil F. In the present embodiment, the third heat exchange unit 96 includes an oil cooler 961.

The oil pump 97 is a pump that sucks and discharges the oil F stored in the oil reservoir ST. The oil circuit 98 is a circuit through which the oil F discharged by the oil pump 97 circulates.

In the present embodiment, the oil F discharged by the oil pump 97 passes through the oil cooler 961, is supplied to the drive unit DU (more specifically, the stator and the rotor of the drive source DS as the rotary electric machine, the gear meshing portions of the transmission TM and the differential gear mechanism DF, a bearing, and the like), and then returns to the oil reservoir ST.

In the present embodiment, the inverter INV (more specifically, a flow channel that is provided adjacent to the inverter INV to cool the inverter INV) is disposed on the downstream side of the heat medium pump 91 in the heat medium circuit 92.

The first valve 931 is disposed on the downstream side of the inverter INV and on the upstream side of the heat medium layer 3 in the heat medium circuit 92. The second valve 932 is disposed on the downstream side of the heat medium layer 3 and on the upstream side of the oil cooler 961 in the heat medium circuit 92.

The first valve 931 and the second valve 932 are configured to switch to one of a first path (see FIG. 4) in which the liquid heat medium H discharged by the heat medium pump 91 sequentially passes through the inverter INV, the first valve 931, the heat medium layer 3, and the second valve 932 to reach the oil cooler 961, and a second path (see FIG. 5) in which the liquid heat medium H discharged by the heat medium pump 91 sequentially passes through the inverter INV, the first valve 931, and the second valve 932, without passing through the heat medium layer 3, to reach the oil cooler 961. The state in which the first path is formed corresponds to the flowing state of the heat medium control device 9. The state in which the second path is formed corresponds to the sealed state of the heat medium control device 9. That is, a state change between the sealed state and the flowing state is performed by switching of the control valve 93.

In the present embodiment, the liquid heat medium H discharged by the heat medium pump 91 exchanges heat with the inverter INV and then reaches the first valve 931. When the heat medium control device 9 is in the flowing state (see FIG. 4), the liquid heat medium H having passed through the inverter INV sequentially passes through the first valve 931, the heat medium layer 3, and the second valve 932 to reach the oil cooler 961. At this time, heat exchange is performed between the liquid heat medium H flowing through the heat medium layer 3 and the oil F in the oil reservoir ST. Therefore, the heat medium control device 9 is brought into the flowing state in a period when the outside air temperature is relatively high, when the oil F is cooled, or the like.

On the other hand, when the heat medium control device 9 is in the sealed state (see FIG. 5), the liquid heat medium H having passed through the inverter INV sequentially passes through the first valve 931 and the second valve 932, without passing through the heat medium layer 3, to reach the oil cooler 961. At this time, since the liquid heat medium H is remaining in the heat medium layer 3, the oil F in the oil reservoir ST is kept warm by the liquid heat medium H. Therefore, when a warm-up operation is performed in a period when the outside air temperature is relatively low, the heat medium control device 9 is brought into the sealed state. In a period when the outside air temperature is relatively low, the viscosity of the oil F increases. Therefore, the amount of the oil F discharged by the oil pump 97 decreases, and the heat exchange between the oil F and the liquid heat medium H by the third heat exchange unit 96 (oil cooler 961) cannot be properly performed. Therefore, by bringing the heat medium control device 9 into the sealed state, temperature rise of the oil F can be promoted.

Subsequently, the liquid heat medium H having passed through the oil cooler 961 passes through the radiator 941 and then returns to the heat medium pump 91. Note that, in the heat medium circuit 92, a path through which the liquid heat medium H having passed through the oil cooler 961 sequentially passes through the refrigerant circuit RC and the battery BT to reach the radiator 941 is also formed.

In the present embodiment, the heat medium layer 3 is disposed on the downstream side of the heat medium pump 91 and on the upstream side of the first heat exchange unit 94 (here, the radiator 941), as described above. As a result, when the heat medium control device 9 is in the sealed state, the heat medium layer 3 is filled with the liquid heat medium H having a relatively high temperature, so that the heat retention performance of the oil reservoir ST can be easily enhanced.

Also, in the present embodiment, the second heat exchange unit 95 (here, the refrigerant circuit RC and the battery BT) is disposed on the downstream side of the heat medium layer 3 and on the upstream side of the first heat exchange unit 94 (here, the radiator 941). As a result, for example, when heating is performed by an air conditioner or when the temperature of the battery BT is raised during the warm-up operation, the heat of the liquid heat medium H whose temperature has risen by the heat exchange with the oil F in the oil reservoir ST can be effectively used on the vehicle side (here, the refrigerant circuit RC and the battery BT).

Also, in the present embodiment, the heat medium layer 3 is disposed on the upstream side of the third heat exchange unit 96 (here, the oil cooler 961). As a result, when the heat medium control device 9 is in the flowing state, the heat exchange between the liquid heat medium H and the oil F can be properly performed. Note that the heat medium layer 3 may be disposed on the downstream side of the third heat exchange unit 96. In this configuration, the heat exchange between the liquid heat medium H and the oil F is performed in the third heat exchange unit 96 before the liquid heat medium H reaches the heat medium layer 3. Therefore, when the heat medium control device 9 is brought into the sealed state, the heat medium layer 3 can be filled with the liquid heat medium H having a relatively high temperature. Therefore, the heat retention performance of the oil reservoir ST can be easily enhanced.

Other Embodiments

(1) In the above embodiment, an example of a configuration has been described in which the drive source DS is the rotary electric machine. Without being limited to such a configuration, however, the drive source DS may be an internal combustion engine.

(2) Note that the configuration disclosed in each of the above-described embodiments can be applied in combination with the configurations disclosed in other embodiments as long as there is no contradiction. Regarding other configurations, the embodiments disclosed in the present specification are merely examples in all respects. Therefore, various modifications can be appropriately made without departing from the gist of the present disclosure.

Summary of Present Embodiment

Hereinafter, outlines of the oil pan (10) and the vehicle drive device (100) described above will be described.

<1> The oil pan (10) is

an oil pan (10) for use in a vehicle drive device (100) including a drive source (DS) and a case (CS) accommodating the drive source (DS) and oil (F), the oil pan (10) including:

an opposing inner surface (1) constituting an oil reservoir (ST) formed inside the case (CS);

an outer surface (2) facing an exterior of the case (CS);

a heat medium layer (3) formed between the opposing inner surface (1) and the outer surface (2), through which a liquid heat medium (H) flows;

an inlet (4) through which the liquid heat medium (H) flows into the heat medium layer (3); and

an outlet (5) through which the liquid heat medium (H) flows out of the heat medium layer (3), in which

the heat medium layer (3) is disposed to cover the opposing inner surface (1) from the outer surface (2) side.

In other words, an oil pan for use in a vehicle drive device including a drive source and a case accommodating the drive source and oil, the oil pan includes:

an opposing inner surface constituting an oil reservoir formed inside the case;

an outer surface facing an exterior of the case;

a heat medium layer formed between the opposing inner surface and the outer surface, through which a liquid heat medium flows;

an inlet through which the liquid heat medium flows into the heat medium layer; and

an outlet through which the liquid heat medium flows out of the heat medium layer, in which

the heat medium layer is disposed to cover the opposing inner surface from the outer surface side.

According to this configuration, by changing the flow state of the liquid heat medium (H) inside the heat medium layer (3), it is possible to cause the liquid heat medium (H) to keep the oil (F) in the oil reservoir (ST) warm, or

to cause the liquid heat medium (H) to exchange heat with the oil in the oil reservoir (ST). Therefore, the heat retention state of the oil (F) in the oil reservoir (ST) can be adjusted, as necessary.

That is, according to this characteristic configuration, by changing a flow state of the liquid heat medium inside the heat medium layer, it is possible to cause the liquid heat medium to keep the oil in the oil reservoir warm, or to cause the liquid heat medium to exchange heat with the oil in the oil reservoir. Therefore, the heat retention state of the oil in the oil reservoir can be adjusted, as necessary.

<2> Here, it is preferable to further include a heat insulation layer (6) formed between the heat medium layer (3) and the outer surface (2), and

to dispose the heat insulation layer (6) so as to cover the heat medium layer (3) from the outer surface (2) side.

In other words, the oil pan further includes a heat insulation layer formed between the heat medium layer and the outer surface, in which

the heat insulation layer is disposed to cover the heat medium layer from the outer surface side.

According to this configuration, the heat of the oil (F) in the oil reservoir (ST) can be made difficult to be transferred to the outside of the case (CS). Therefore, the heat retention of the oil (F) in the oil reservoir (ST) and the heat exchange between the liquid heat medium (H) and the oil (F) in the oil reservoir (ST) can be efficiently performed.

<3> The vehicle drive device (100) is

a vehicle drive device (100) including the oil pan (10), the vehicle drive device (100) including

a heat medium control device (9) that controls a flow state of the liquid heat medium (H), in which

the heat medium control device (9) is configured to allow the flow state to be changed between a sealed state in which, while the heat medium layer (3) is filled with the liquid heat medium (H), a flow of the liquid heat medium (H) is stopped, and a flowing state in which the liquid heat medium (H) is caused to flow from the inlet (4) toward the outlet (5) in the heat medium layer (3).

In other words, the vehicle drive device is

a vehicle drive device including the oil pan, the vehicle drive device includes:

a heat medium control device that controls a flow state of the liquid heat medium, in which

the heat medium control device is configured to allow the flow state to be changed between a sealed state in which, while the heat medium layer is filled with the liquid heat medium, a flow of the liquid heat medium is stopped, and a flowing state in which the liquid heat medium is caused to flow from the inlet toward the outlet in the heat medium layer.

According to this configuration, by bringing the heat medium control device (9) into the sealed state, it is possible to cause the liquid heat medium (H) to keep the oil (F) in the oil reservoir (ST) warm. In addition, by bringing the heat medium control device (9) into the flowing state, heat exchange between the liquid heat medium (H) and the oil (F) in the oil reservoir (ST) can be performed. Therefore, the heat retention state of the oil (F) in the oil reservoir (ST) can be properly adjusted.

That is, according to this characteristic configuration, by bringing the heat medium control device into the sealed state, it is possible to cause the liquid heat medium to keep the oil in the oil reservoir warm. In addition, by bringing the heat medium control device into the flowing state, heat exchange between the liquid heat medium and the oil in the oil reservoir can be performed. Therefore, the heat retention state of the oil in the oil reservoir can be properly adjusted.

<4> Here, the heat medium control device (9) includes:

a heat medium pump (91) that sucks and discharges the liquid heat medium (H);

a heat medium circuit (92) through which the liquid heat medium (H) discharged by the heat medium pump (91) circulates;

a control valve (93) that switches the flow state of the liquid heat medium (H) in the heat medium circuit (92);

a first heat exchange unit (94) that performs heat exchange between the liquid heat medium (H) and the outside air; and

a second heat exchange unit (95) that performs heat exchange for using the heat of the liquid heat medium (H) on the vehicle side, in which

a state change between the sealed state and the flowing state is performed by switching of the control valve (93), and

it is preferable that the heat medium layer (3) is disposed on the downstream side of the heat medium pump (91) and on the upstream side of the first heat exchange unit (94), and

that the second heat exchange unit (95) is disposed on the downstream side of the heat medium layer (3) and on the upstream side of the first heat exchange unit (94).

In other words, in the vehicle drive device, the heat medium control device includes

a heat medium pump that sucks and discharges the liquid heat medium,

a heat medium circuit through which the liquid heat medium discharged by the heat medium pump circulates,

a control valve that switches the flow state of the liquid heat medium in the heat medium circuit,

a first heat exchange unit that performs heat exchange between the liquid heat medium and outside air, and

a second heat exchange unit that performs heat exchange for using heat of the liquid heat medium on a vehicle side;

a state change between the sealed state and the flowing state is performed by switching of the control valve;

the heat medium layer is disposed on a downstream side of the heat medium pump and on an upstream side of the first heat exchange unit; and

the second heat exchange unit is disposed on a downstream side of the heat medium layer and on an upstream side of the first heat exchange unit.

According to this configuration, a state change between the sealed state and the flowing state of the heat medium control device (9) can be properly performed by switching of the control valve (93).

According to the present configuration, the heat medium layer (3) is disposed on the upstream side of the first heat exchange unit (94), and thus when the heat medium control device (9) is in the sealed state, the heat medium layer (3) is filled with the liquid heat medium (H) having a relatively high temperature. Therefore, the heat retention performance of the oil reservoir (ST) can be easily enhanced. In addition, the second heat exchange unit (95) is disposed on the downstream side of the heat medium layer (3), so that the heat of the liquid heat medium (H) whose temperature has risen by the heat exchange with the oil (F) in the oil reservoir (ST) can be effectively used on the vehicle side.

The technology according to the present disclosure can be used for an oil pan and a vehicle drive device including the oil pan.

The principles, preferred embodiment and mode of operation of the present invention have been described in the foregoing specification. However, the invention which is intended to be protected is not to be construed as limited to the particular embodiments disclosed. Further, the embodiments described herein are to be regarded as illustrative rather than restrictive. Variations and changes may be made by others, and equivalents employed, without departing from the spirit of the present invention. Accordingly, it is expressly intended that all such variations, changes and equivalents which fall within the spirit and scope of the present invention as defined in the claims, be embraced thereby.

Claims

1. An oil pan for use in a vehicle drive device including a drive source and a case accommodating the drive source and oil, the oil pan comprising:

an opposing inner surface constituting an oil reservoir formed inside the case;

an outer surface facing an exterior of the case;

a heat medium layer formed between the opposing inner surface and the outer surface, through which a liquid heat medium flows;

an inlet through which the liquid heat medium flows into the heat medium layer; and

an outlet through which the liquid heat medium flows out of the heat medium layer, wherein

the heat medium layer is disposed to cover the opposing inner surface from the outer surface side.

2. The oil pan according to claim 1, further comprising a heat insulation layer formed between the heat medium layer and the outer surface, wherein the heat insulation layer is disposed to cover the heat medium layer from the outer surface side.

3. A vehicle drive device including the oil pan according to claim 1, the vehicle drive device comprising:

a heat medium control device that controls a flow state of the liquid heat medium, wherein

the heat medium control device is configured to allow the flow state to be changed between a sealed state in which, while the heat medium layer is filled with the liquid heat medium, a flow of the liquid heat medium is stopped, and a flowing state in which the liquid heat medium is caused to flow from the inlet toward the outlet in the heat medium layer.

4. A vehicle drive device including the oil pan according to claim 2, the vehicle drive device comprising:

a heat medium control device that controls a flow state of the liquid heat medium, wherein

the heat medium control device is configured to allow the flow state to be changed between a sealed state in which, while the heat medium layer is filled with the liquid heat medium, a flow of the liquid heat medium is stopped, and a flowing state in which the liquid heat medium is caused to flow from the inlet toward the outlet in the heat medium layer.

5. The vehicle drive device according to claim 3, wherein: the heat medium control device includes a heat medium pump that sucks and discharges the liquid heat medium, a heat medium circuit through which the liquid heat medium discharged by the heat medium pump circulates, a control valve that switches the flow state of the liquid heat medium in the heat medium circuit, a first heat exchange unit that performs heat exchange between the liquid heat medium and outside air, and a second heat exchange unit that performs heat exchange for using heat of the liquid heat medium on a vehicle side; a state change between the sealed state and the flowing state is performed by switching of the control valve; the heat medium layer is disposed on a downstream side of the heat medium pump and on an upstream side of the first heat exchange unit; and the second heat exchange unit is disposed on a downstream side of the heat medium layer and on an upstream side of the first heat exchange unit.

6. The vehicle drive device according to claim 4, wherein: the heat medium control device includes a heat medium pump that sucks and discharges the liquid heat medium, a heat medium circuit through which the liquid heat medium discharged by the heat medium pump circulates, a control valve that switches the flow state of the liquid heat medium in the heat medium circuit, a first heat exchange unit that performs heat exchange between the liquid heat medium and outside air, and a second heat exchange unit that performs heat exchange for using heat of the liquid heat medium on a vehicle side; a state change between the sealed state and the flowing state is performed by switching of the control valve; the heat medium layer is disposed on a downstream side of the heat medium pump and on an upstream side of the first heat exchange unit; and the second heat exchange unit is disposed on a downstream side of the heat medium layer and on an upstream side of the first heat exchange unit.