Vehicle drive systems

Abstract

This enhances the heat retention effect of the oil and makes it easier to improve the efficiency of heat recovery from the oil. [Solution] The vehicle drive system comprises a rotating electric machine 1, a power transmission mechanism, the rotating electric machine 1, the power transmission mechanism, and a case 3 for storing oil. An insulating section 5 is provided in a target area A, which is at least one of an oil level corresponding area 40A corresponding to the oil level 40 of the oil reservoir 4 inside the case 3, and an outlet corresponding area 34A corresponding to the oil outlet 34 from the oil reservoir 4 inside the case 3. The insulating section 5 is not provided in any area inside the case 3 other than the target area A.

Description

Technical Field

[0001] The present invention relates to a vehicle drive device including a rotating electric machine, an output member drivingly connected to a wheel, a power transmission mechanism that transmits power between the rotating electric machine and the output member, and a case that houses the rotating electric machine, the power transmission mechanism, and oil.

Background Art

[0002] For example, Japanese Patent Application Laid-Open No. 2020-091001 (Patent Document 1) discloses a vehicle drive device including a rotating electric machine, a power transmission mechanism, and a case that houses oil. The reference numerals in parentheses used in the following description of the background art are those of Patent Document 1.

[0003] The vehicle drive device disclosed in Patent Document 1 includes a rotating electric machine (13), a power transmission device (2), and a case (3) that houses oil. An oil reservoir (9) where oil accumulates is formed at the lower part of the case (3). The oil in the oil reservoir (9) is sucked by an oil pump (15) and supplied to the rotating electric machine (13). The oil sucked from the oil reservoir (9) by the oil pump (15) is cooled by an oil cooler and then supplied to the rotating electric machine (13). This contributes to the cooling of the rotating electric machine (13).

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] Incidentally, the heat in the oil, which rises due to the heat generated by rotating electric machinery, can be recovered and used, for example, for heating the cabin. However, if the temperature of the oil stored in the oil reservoir before heat recovery decreases due to heat dissipation to the outside of the case, the efficiency of heat recovery from the oil decreases.

[0006] Therefore, there is a need for technologies that enhance the heat retention effect of oil and improve the efficiency of heat recovery from oil. [Means for solving the problem]

[0007] Rotating electric machines and, An output member that is driven and connected to the wheel, A power transmission mechanism that transmits power between the rotating electric machine and the output member, The rotating electric machine, the power transmission mechanism, and the case for containing oil, A vehicle drive system equipped with, An oil reservoir is formed at the bottom of the aforementioned case, A heat insulating portion is provided in a target region which is at least one of the oil level corresponding region in the case corresponding to the oil level of the oil reservoir, and the outlet corresponding region in the case corresponding to the oil outlet from the oil reservoir, while the heat insulating portion is not provided in any region in the case other than the target region.

[0008] This configuration minimizes the amount of heat dissipated from the oil to the outside of the case. Consequently, it enhances the heat retention effect of the oil and makes it easier to improve the heat recovery efficiency of the oil. Furthermore, this configuration allows for the provision of insulating sections only in areas with high thermal insulation effect, while omitting insulating sections in areas with low thermal insulation effect. Therefore, a high thermal insulation effect can be achieved with a relatively small amount of insulating section, and it is easier to suppress the cost increase of the vehicle drive system caused by providing insulating sections in areas with low thermal insulation effect.

[0009] Further features and advantages of the technology relating to this disclosure will become clearer from the following description of exemplary and non-limiting embodiments, with reference to the drawings. [Brief explanation of the drawing]

[0010] [Figure 1] Skeleton diagram of a vehicle drive system [Figure 2] Exploded perspective view of a vehicle's drive system [Figure 3] Schematic diagram showing oil circulation [Figure 4] Cross-sectional view of a vehicle drive system [Figure 5] VV section diagram in Figure 4 [Figure 6] VI-VI section view in Figure 4 [Modes for carrying out the invention]

[0011] [Definition] In describing this embodiment, the following definitions are used.

[0012] The term "rotating electric machine" shall be used as a concept that includes motors, generators, and, if necessary, motor-generators that perform both motor and generator functions.

[0013] "Driven connection" refers to a state in which two rotating elements are connected in a manner that enables the transmission of driving force. This concept includes a state in which the two rotating elements are connected so as to rotate as a single unit, or a state in which the two rotating elements are connected in a manner that enables the transmission of 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, and chains. Such transmission members may also include engagement devices that selectively transmit rotation and driving force, such as friction engagement devices and meshing engagement devices.

[0014] [Embodiment] The following describes an embodiment of a vehicle drive system with reference to the drawings.

[0015] As shown in FIG. 1, the vehicle drive device 100 includes a rotary electric machine 1, an output member 98 that is drivingly connected to a wheel W, a power transmission mechanism 2 that transmits power between the rotary electric machine 1 and the output member 98, and the rotary electric machine 1, the power transmission mechanism 2, and a case 3 that houses oil.

[0016] Examples of vehicles equipped with the vehicle drive device 100 include hybrid vehicles, plug-in hybrid vehicles, battery vehicles, fuel cell vehicles, etc. that include an internal combustion engine and a rotary electric machine.

[0017] In FIG. 1, a so-called single-axis E-axle is illustrated in which a plurality of main rotating elements constituting the vehicle drive device 100 are arranged on the same axis within the case 3. However, the present disclosure is not limited to this, and the vehicle drive device 100 according to the present disclosure can also be applied to, for example, a so-called three-axis E-axle in which the main rotating elements are distributed and arranged on three axes.

[0018] In the present embodiment, the power transmission mechanism 2 includes a reduction gear 21 and a differential gear device 22. The driving rotation generated from the rotary electric machine 1 is decelerated by the reduction gear 21 and distributed to a pair of wheels W by the differential gear device 22. The differential gear device 22 is drivingly connected to the wheel W via a drive shaft 99.

[0019] In the example shown in FIG. 1, the reduction gear 21 is configured using a planetary gear mechanism and includes a sun gear, a carrier, and a ring gear. Thereby, the driving rotation generated from the rotary electric machine 1 is decelerated.

[0020] In the present embodiment, the output member 98 is a rotating element that constitutes the differential gear device 22. However, the present disclosure is not limited to this, and the output member 98 may be a rotating element interposed between the differential gear device 22 and the drive shaft 99.

[0021] FIG. 2 is an exploded perspective view of the vehicle drive device 100.

[0022] An oil reservoir 4 is formed at the bottom of case 3, where oil accumulates. This oil is mainly used for lubrication and cooling of the rotating electric machine 1 and the power transmission mechanism 2. In this embodiment, case 3 comprises a first case 31 and a second case 32. The oil reservoir 4 is formed inside the first case 31.

[0023] The first case 31 houses the rotating electric machine 1 and the power transmission mechanism 2. In this embodiment, the vehicle drive unit 100 is equipped with an oil pump P that sucks in and discharges oil from the oil reservoir 4. In this example, the oil pump P is housed in the first case 31.

[0024] In this embodiment, the first case 31 is cylindrical, with openings 310a and 310b formed at both ends. With the rotating electric machine 1, power transmission mechanism 2, oil pump P, etc. housed inside the first case 31, the openings 310a and 310b are closed by covers 33a and 33b, thereby sealing the first case 31.

[0025] The second case 32 houses an inverter module, a power supply module, and other components for driving and controlling the rotating electric machine 1. In the illustrated example, the second case 32 houses a heat exchanger 9. An oil cooler can be exemplified as the heat exchanger 9. The second case 32 is placed on top of the first case 31 when the vehicle drive unit 100 is mounted on the vehicle.

[0026] Here, the temperature of the oil supplied to the rotating electric machine 1 rises due to the heat generated by the rotating electric machine 1. The heat from the oil due to the temperature rise can be recovered and used, for example, for heating the cabin or warming up the battery.

[0027] As shown in Figure 3, the oil in the oil reservoir 4 circulates through the vehicle drive unit 100. As described above, the oil in the oil reservoir 4, whose temperature has risen due to the heat generated from the rotating electric machine 1, is sucked out by the oil pump P.

[0028] The oil is then supplied to the heat exchanger 9, where it exchanges heat with a heat transfer medium (such as cooling water or refrigerant for air conditioning). In other words, the heat exchanger 9 is configured to exchange heat between the heat transfer medium and the oil supplied by the oil pump P. This allows for heat recovery.

[0029] The temperature of the oil after heat exchange by the heat exchanger 9 is lower than before the heat exchange. This oil is supplied to the rotating electric machine 1 and used to cool the heat-generating rotating electric machine 1. In other words, heat exchange takes place between the low-temperature oil and the heat-generating rotating electric machine 1.

[0030] The temperature of the oil used to cool the rotating electric machine 1 rises again. The now hot oil is supplied back to the oil reservoir 4.

[0031] In this way, the oil circulates through the vehicle drive system 100 and is used for heat recovery through heat exchange during circulation (and also for cooling the rotating electric machine 1). Therefore, in order to facilitate heat recovery, it is preferable to keep the temperature of the oil supplied to the heat exchanger 9 high. To achieve this, it is necessary to suppress the dissipation of heat from the oil stored in the oil reservoir 4 to the outside of the case 3.

[0032] As shown in Figures 4 to 6, the region corresponding to the oil level 40 of the oil reservoir 4 inside the case 3 is defined as the oil level region 40A. The region corresponding to the oil outlet 34 from the oil reservoir 4 inside the case 3 is defined as the outlet region 34A.

[0033] In this embodiment, at least one of the oil level area 40A and the outlet area 34A is designated as the target area A, and the heat insulating section 5 is provided in the target area A. In this embodiment, both the oil level area 40A and the outlet area 34A are the target area A. That is, the heat insulating section 5 is provided in both the oil level area 40A and the outlet area 34A. The heat insulating section 5 is provided in a position that comes into contact with the oil and has the function of suppressing the heat from the oil from being released to the case 3 or the outside.

[0034] In this embodiment, the heat insulating section 5 comprises a heat insulating material coated on the inside of the case 3. In other words, the heat insulating section 5 is the area inside the case 3 that is coated with a heat insulating material. Foamed resin or synthetic resin can be used as the heat insulating material constituting the heat insulating section 5. For example, silica aerogel or polyamide resin can be used as the heat insulating material. Using a material containing air bubbles, such as foamed resin, as the heat insulating material can be expected to provide a high heat insulating effect. These materials can be directly applied to the target area A inside the case 3, or an adhesive substance coated with these materials can be attached to the target area A to coat the target area A with the heat insulating material.

[0035] In this embodiment, both the oil level area 40A and the outlet area 34A are the target area A where the heat insulating section 5 is provided. These oil level area 40A and outlet area 34A are set in locations within the case 3 where the heat insulating effect is considered to be relatively high, that is, locations where heat dissipation is likely to occur.

[0036] Where the oil flow velocity is high, heat transfer to the surroundings (case 3, etc.) is more easily promoted compared to where the oil flow velocity is low. Inside case 3, the oil flow velocity is relatively high at and near the oil surface 40, and inside and near the intake passage 7. At the oil surface 40, the flow velocity tends to be relatively high because oil falls onto the oil surface 40 from the rotating electric machine 1 and the power transmission mechanism 2. In the intake passage 7, the flow of oil is generated by the suction of the oil pump P, so the flow velocity tends to be relatively high. This is especially noticeable in areas with a small flow path cross-sectional area.

[0037] As shown in Figure 4, the oil level corresponding region 40A is a region provided to extend horizontally along the oil level 40. In this embodiment, the oil level corresponding region 40A extends continuously around the inner surface of the case 3 at the height of the oil level 40 (see Figure 2). The oil level corresponding region 40A is set on the inner surface of the case wall 311, and the heat insulating portion 5 is provided in the oil level corresponding region 40A.

[0038] The presence of the heat insulating section 5 in the oil level region 40A (target region A), where the flow velocity tends to be relatively high, makes it easier to enhance the heat insulating effect of the heat insulating section 5. Consequently, the heat retention effect of the oil inside the case 3 can be improved, and the oil in the oil storage section 4 can be supplied to the heat exchanger 9 while maintaining a high temperature.

[0039] In this embodiment, the oil level range 40A is set to a height that includes the height of the oil level 40 and the range below the oil level 40. This "height of the oil level 40" may be the minimum height of the oil level 40 during the operation of the rotating electric machine 1, the maximum height of the oil level 40 when the rotating electric machine 1 is stationary, or the average height obtained by taking the average of the fluctuating oil levels 40.

[0040] As shown in Figures 5 and 6, the outlet region 34A is the region corresponding to the outlet 34. In this embodiment, the outlet 34 includes an oil intake passage 7 by the oil pump P and an opening 70 that opens into the oil reservoir 4. The outlet region 34A includes at least one of the opening region 34Aa, which extends from the opening 70 toward the side where the opening 70 opens, and the inner surface region 34Ab of the intake passage 7. In this example, both the opening region 34Aa and the inner surface region 34Ab are included in the outlet region 34A.

[0041] The presence of the heat insulating section 5 in the outlet region 34A (target region A), where the flow velocity tends to be relatively high, makes it easier to enhance the heat insulating effect of the heat insulating section 5. Consequently, the heat retention effect of the oil inside the case 3 can be improved, and the oil in the oil storage section 4 can be supplied to the heat exchanger 9 while maintaining a high temperature.

[0042] As shown in Figure 5, the suction passage 7 includes a first suction passage 71 connected to the oil reservoir 4, a second suction passage 72 connected to the oil pump P, and an intermediate passage 73 connecting the first suction passage 71 and the second suction passage 72. Oil drawn from the oil reservoir 4 by the oil pump P reaches the oil pump P through the first suction passage 71, the intermediate passage 73, and the second suction passage 72. The intermediate passage 73 is provided with a strainer 74 for filtering the oil, and the filtered oil is configured to reach the oil pump P through the second suction passage 72. Although detailed illustrations are omitted, the oil that reaches the oil pump P is discharged into a passage connected to the heat exchanger 9.

[0043] In this embodiment, the flow path cross-sectional area of ​​the first intake passage 71 is smaller than the flow path cross-sectional area of ​​the intermediate passage 73. Therefore, the flow velocity of oil passing through the first intake passage 71 tends to be higher than the flow velocity of oil passing through the intermediate passage 73. In this embodiment, the inner surface of the first intake passage 71 is defined as the inner surface region 34Ab, and a heat insulating section 5 is provided in this inner surface region 34Ab. This allows the heat insulating section 5 to be provided in a location where the oil flow velocity is relatively high and a high heat insulating effect can be expected.

[0044] In this embodiment, the flow path cross-sectional area of ​​the second intake passage 72 is smaller than the flow path cross-sectional area of ​​the intermediate passage 73. Therefore, the flow velocity of oil passing through the second intake passage 72 tends to be higher than the flow velocity of oil passing through the intermediate passage 73. In this embodiment, the inner surface of the second intake passage 72 is defined as the inner surface region 34Ab, and an insulating section 5 is provided in this inner surface region 34Ab. This allows the insulating section 5 to be provided in locations where the oil flow velocity is relatively high and a high insulating effect can be expected. Thus, in this embodiment, insulating sections 5 are provided on the inner surfaces of the first intake passage 71 and the second intake passage 72.

[0045] As shown in Figures 5 and 6, the opening region 34Aa is a region that extends continuously from the opening 70 of the intake passage 7 to the outside of the intake passage 7. The opening region 34Aa is set on the inner surface of the case bottom 312, and the heat insulating section 5 is provided in the opening region 34Aa. Due to the operation of the oil pump P, oil flows from multiple directions toward the center of the opening 70 in the vicinity of the opening 70. Therefore, in this example, the opening region 34Aa is set to cover a wider area than the diameter of the opening 70. The flow velocity of the oil flowing toward the center of the opening 70 from multiple directions increases as it approaches the opening 70. Therefore, the heat insulating effect of providing the heat insulating section 5 is higher the closer the opening region 34Aa is to the opening 70.

[0046] Thus, by installing the insulating section 5 in areas with high thermal insulation, such as area A, the heat retention effect of the oil can be enhanced. On the other hand, there is little point in installing the insulating section 5 in areas with relatively low thermal insulation. Moreover, the cost increase resulting from installing the insulating section 5 becomes significant.

[0047] Therefore, the heat insulating section 5 is not provided in areas other than the target area A within Case 3. This makes it easier to suppress the cost increase of the vehicle drive unit 100 that would occur if the heat insulating section 5 were provided in areas with low heat insulating effect.

[0048] In the vehicle drive system 100 according to this disclosure, by providing heat insulating sections 5 specifically in areas where the flow velocity tends to be high, i.e., areas where heat dissipation is likely to occur, heat dissipation of the oil in those areas can be suppressed, thereby enhancing the heat dissipation suppression effect. On the other hand, by not providing heat insulating sections 5 in areas where the flow velocity is relatively low, i.e., areas where heat dissipation is relatively unlikely to occur, the areas where heat insulating sections 5 are provided can be limited, thereby suppressing an increase in the cost of the vehicle drive system 100.

[0049] In this embodiment, a thickness-increasing section 6 is provided in the region of case 3 corresponding to the target region A, thereby increasing the thickness of case 3. The thickness-increasing section 6 ensures a longer heat transfer path for transferring heat from the oil inside case 3 to the outside of case 3. As a result, the temperature of the outer surface of case 3 that is not in contact with the oil can be kept low, and the amount of heat from the oil inside case 3 that is dissipated to the outside through case 3 can be reduced.

[0050] As shown in Figure 4, the thickness-increasing portion 6 is provided in the region corresponding to the oil level area 40A. More specifically, the thickness-increasing portion 6 is provided on the outer surface of the case wall 311 and is positioned so as to at least partially overlap the oil level area 40A (insulation portion 5) provided on the inner surface of the case wall 311 when viewed in the thickness direction of the case wall 311. The thickness-increasing portion 6 provided in correspondence with the oil level area 40A is constructed using ribs that protrude outward from the outer surface of the case wall 311. In the example shown in Figure 2, the thickness-increasing portion 6 extends continuously around the outer surface of the case 3 along the oil level 40.

[0051] In this embodiment, as shown in Figure 6, the thickness-increasing portion 6 is also provided in the region corresponding to the opening region 34Aa (exit region 34A). More specifically, the thickness-increasing portion 6 is provided on the outer surface of the case bottom 312, and is positioned so as to at least partially overlap with the opening region 34Aa (heat-insulating portion 5) provided on the inner surface of the case bottom 312 when viewed in the thickness direction of the case bottom 312. The thickness-increasing portion 6 is constructed using ribs or receiving bosses that protrude downward from the outer surface of the case bottom 312.

[0052] In this way, by providing the thickened portion 6 in addition to the heat insulating portion 5, the heat retention effect of the oil can be further enhanced. Furthermore, the locations where these heat insulating portion 5 and thickened portion 6 are provided are limited to specific locations only. Therefore, it is possible to obtain the above-mentioned heat retention effect while suppressing an increase in the cost of the vehicle drive unit 100.

[0053] [Other Embodiments] Next, other embodiments will be described.

[0054] (1) In the above embodiment, an example was described in which the oil level corresponding region 40A extends continuously around the inner surface of the case 3 at the height of the oil level 40. However, the oil level corresponding region 40A may be set intermittently along the oil level 40 on the inner surface of the case 3, or it may be set only in a part of it.

[0055] (2) In the above embodiment, an example was described in which the thickness-increasing portion 6 extends continuously around the outer surface of the case 3 along the oil surface 40. However, the example is not limited to this example, and the thickness-increasing portion 6 may be provided intermittently along the oil surface 40 on the outer surface of the case 3, or only in part.

[0056] (3) In the above embodiment, an example was described in which the thickness-increasing portion 6 is provided on the outer surface of the case wall 311. However, the example is not limited to this, and the thickness-increasing portion 6 may be provided on the inner surface of the case wall 311, or on both the outer surface and the inner surface.

[0057] (4) In the above embodiment, an example was described in which the thickness-increasing portion 6 is provided on the outer surface of the case bottom 312. However, the example is not limited to this, and the thickness-increasing portion 6 may be provided on the inner surface of the case bottom 312, or on both the outer surface and the inner surface.

[0058] (5) In the above embodiment, an example was described in which a thickness-increasing portion 6 is provided in addition to the heat-insulating portion 5. However, the example is not limited to this example, and the thickness-increasing portion 6 may not be provided.

[0059] (6) In the above embodiment, an example was described in which both the oil level area 40A and the outlet area 34A are the target area A, and the heat insulating section 5 is provided in the target area A. However, the invention is not limited to such an example, and only one of the oil level area 40A and the outlet area 34A may be the target area A, and the heat insulating section 5 may be provided only in the target area A.

[0060] (7) In the above embodiment, an example was described in which both the opening region 34Aa and the inner surface region 34Ab are outlet-corresponding regions 34A, and the heat insulating portion 5 is provided in the outlet-corresponding regions 34A. However, the example is not limited to this example, and only one of the opening region 34Aa or the inner surface region 34Ab may be an outlet-corresponding region 34A, and the heat insulating portion 5 may be provided only in the outlet-corresponding region 34A.

[0061] (8) In the above embodiment, an example was described in which both the inner surface of the first intake passage 71 and the inner surface of the second intake passage 72 are inner surface regions 34Ab, and the heat insulating portion 5 is provided in these inner surface regions 34Ab. However, the embodiment is not limited to this example, and it is also possible that only one of the inner surface of the first intake passage 71 or the inner surface of the second intake passage 72 is an inner surface region 34Ab, and the heat insulating portion 5 is provided only in that inner surface region 34Ab. The range of the inner surface region 34Ab on the inner surface of the first intake passage 71 can be arbitrarily determined. Similarly, the range of the inner surface region 34Ab on the inner surface of the second intake passage 72 can be arbitrarily determined.

[0062] (9) The configurations disclosed in 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.

[0063] [Summary of this embodiment] The following is a summary of this embodiment.

[0064] Rotating electric machine (1), An output member (98) is driven and connected to the wheel (W), A power transmission mechanism (2) that transmits power between the rotating electric machine (1) and the output member (98), The rotating electric machine (1), the power transmission mechanism (2), and the case for containing oil (3) A vehicle drive system (100) equipped with, An oil reservoir (4) is formed at the bottom of the case (3) where oil accumulates. A heat insulating section (5) is provided in a target region (A) which is at least one of the following: an oil level corresponding region (40A) corresponding to the oil level (40) of the oil reservoir (4) inside the case (3), and an outlet corresponding region (34A) corresponding to the oil outlet (34) from the oil reservoir (4) inside the case (3). The heat insulating section (5) is not provided in any region inside the case (3) other than the target region (A).

[0065] This configuration allows for minimizing the amount of heat from the oil that is released to the outside of the case (3). Therefore, the heat retention effect of the oil can be enhanced, and the heat recovery efficiency of the oil can be easily improved. Furthermore, this configuration allows for the provision of insulating sections (5) only in areas with high heat insulation effect, and omitting insulating sections (5) in areas with low heat insulation effect. As a result, a high heat insulation effect can be obtained with a relatively small number of insulating sections (5), and it is easier to suppress the cost increase of the vehicle drive unit (100) caused by providing insulating sections (5) in areas with low effect.

[0066] The aforementioned heat insulating section (5) preferably comprises a heat insulating material coated on the inside of the case (3).

[0067] With this configuration, an insulating section (5) can be easily provided inside the case (3), and the cost of providing the insulating section (5) can be kept low.

[0068] It is preferable that a thickness-increasing portion (6) is provided in the region of the case (3) corresponding to the target region (A), in which the thickness of the case (3) is increased.

[0069] With this configuration, by providing a partially thickened section (6) in the case (3), it is easier to keep the temperature of the outer surface of the case (3) in the area corresponding to the target area (A) low. As a result, the amount of heat from the oil released to the outside through the case (3) can be reduced, making it easier to improve the heat recovery efficiency of the oil.

[0070] Preferably, the oil level corresponding region (40A) is a region that extends horizontally along the oil level (40).

[0071] In this configuration, near the oil level (40) of the oil reservoir (4), heat is easily transferred from the oil to the case (3) due to factors such as the fact that the oil, which is hot after cooling various parts of the vehicle drive unit (100), falls down, the oil flow velocity tends to be higher than elsewhere as this oil falls down, and high-temperature oil is lighter in specific gravity than low-temperature oil and therefore tends to rise to the oil level. In this configuration, by providing an insulating section (5) in such a region, the amount of heat from the oil released to the outside through the case (3) can be reduced, making it easier to improve the heat recovery efficiency of the oil.

[0072] The oil pump (P) is provided to draw in and discharge oil from the oil reservoir (4), The outlet (34) comprises an oil intake passage (7) by the oil pump (P) and an opening (70) that opens to the oil reservoir (4). The outlet corresponding region (34A) preferably includes at least one of the opening region (34Aa) that extends from the opening (70) toward the side where the opening (70) opens, and the inner surface region (34Ab) of the intake passage (7).

[0073] In the opening region (34Aa) on the opening side of the opening (70) where the oil intake passage (7) by the oil pump (P) opens, and in the inner surface region (34Ab) of the intake passage (7), the oil flow velocity tends to be higher than elsewhere, making it easier for heat to be transferred from the oil to the case (3). With this configuration, by providing an insulating section (5) in such regions, the amount of heat from the oil released to the outside through the case (3) can be reduced, making it easier to improve the heat recovery efficiency of the oil. [Industrial applicability]

[0074] The technology relating to this disclosure can be used in 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, and a case for containing oil. [Explanation of Symbols]

[0075] 100: Vehicle drive unit, 1: Rotating electric machine, 2: Power transmission mechanism, 3: Case, 34: Outlet, 34A: Outlet area, 34Aa: Opening area, 34Ab: Inner surface area, 4: Oil reservoir, 40: Oil level, 40A: Oil level area, 5: Heat insulation section, 6: Thickness increase section, 7: Intake passage, 70: Opening, 98: Output member, A: Target area, P: Oil pump, W: Wheel

Claims

1. Rotating electric machines and, An output member that is driven and connected to the wheel, A power transmission mechanism that transmits power between the rotating electric machine and the output member, The rotating electric machine, the power transmission mechanism, and the case for containing oil, A vehicle drive system equipped with, An oil reservoir is formed at the bottom of the aforementioned case, A vehicle drive device, wherein a heat insulating portion is provided in a target region which is at least one of an oil level corresponding region corresponding to the oil level of the oil reservoir inside the case, and an outlet corresponding region corresponding to the oil outlet from the oil reservoir inside the case, and the heat insulating portion is not provided in any region inside the case other than the target region.

2. The vehicle drive device according to claim 1, wherein the heat insulating portion comprises a heat insulating material coated inside the case.

3. The vehicle drive device according to claim 1 or 2, wherein a thickness-increasing portion is provided in the region of the case corresponding to the target region, wherein the thickness of the case is increased.

4. The vehicle drive device according to claim 1 or 2, wherein the oil level corresponding region is a region provided so as to extend horizontally along the oil level.

5. The oil pump is provided to draw in and discharge oil from the oil reservoir, The outlet comprises an oil intake passage by the oil pump and an opening that opens to the oil reservoir. The vehicle drive device according to claim 1 or 2, wherein the outlet corresponding region includes at least one of the opening region extending from the opening toward the side where the opening is opened and the inner surface region of the intake passage.

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