Vehicle driving apparatus

Abstract

To provide a vehicle driving apparatus capable of efficiently utilizing heat.SOLUTION: A vehicle driving apparatus comprises: a cooling plate 3 with a cooling fluid L flowing inside to cool electronic components for power conversion; an electric motor for driving a vehicle; a case C for accommodating the cooling plate 3 and the electric motor; and a fastening member 16 for fixing the cooling plate 3 to the case C. A heat insulation member 15 is interposed between the cooling plate 3 to be fastened and the fastening member 16 at a boundary position where they face each other in a fastening direction, and between the cooling plate 3 and the case C at a boundary position where they face each other in the fastening direction.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to a vehicle drive system. [Background technology]

[0002] Patent Document 1 describes a power supply device having a housing, which is mounted on a vehicle such as an electric car. The housing has a partition member configured as an aluminum heat dissipation fin, and describes a configuration in which a first aluminum cover member and a second aluminum cover member are fixed to the partition member by screw fastening. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2020-61892 Summary of the Invention [Problem to be solved by the invention]

[0004] BACKGROUND ART In recent years, battery electric vehicles (BEVs) that are equipped with an electric motor as a driving source and run on power supplied from a battery have become increasingly popular.

[0005] Taking a battery vehicle equipped with a vehicle drive unit as an example, this vehicle drive unit has a configuration in which an electric motor and a reduction gear are housed in a metal case, and a power control circuit that controls the power supplied to the electric motor is provided in the upper part of the case.

[0006] In vehicles equipped with an internal combustion engine, for example, it is easy to utilize the heat generated by the internal combustion engine to regulate the temperature inside the cabin, but battery-powered vehicles, which do not have an engine, require an effective heat source.

[0007] Therefore, in battery vehicles, it is conceivable to use the electric motor, power control circuit, etc. as a heat source. However, because these are fastened to the metal case of the vehicle drive unit with metal bolts, washers, etc., much of the heat is transferred to the case, raising concerns that it may be difficult to effectively utilize the heat.

[0008] For these reasons, there is a demand for a vehicle drive system that can efficiently utilize heat. [Means for solving the problem]

[0009] The characteristic configuration of the vehicle drive device of the present invention is that it comprises a cooling plate through which a cooling fluid flows to cool electronic components for power conversion, an electric motor for vehicle operation, a case that houses the cooling plate and the electric motor, and fastening members that fix at least the cooling plate to the case, and that insulating members are interposed at boundary positions where the cooling plate and the fastening member, which are fastening objects, face each other in the fastening direction, and at boundary positions where the cooling plate and the case face each other in the fastening direction.

[0010] According to this configuration, the cooling plate removes heat from the electronic components for power conversion, thereby increasing the temperature of the cooling fluid in the cooling plate. Furthermore, heat insulating members are interposed at the boundary positions where the cooling plate and the fastening member, which are fastening objects, face each other in the fastening direction, and at the boundary positions where the cooling plate and the case face each other in the fastening direction. This prevents direct contact between the cooling plate and the fastening member, and prevents heat from the cooling plate from being transferred to the case via the fastening member. Furthermore, since the cooling plate and the case do not come into direct contact, heat from the cooling plate is not transferred to the case. Since heat conduction from the cooling plate is thus suppressed, the temperature drop of the coolant whose temperature has risen in the cooling plate is suppressed, allowing the heat to be utilized outside the case. Thus, a vehicle drive device capable of efficient heat utilization has been configured.

[0011] The characteristic configuration of the vehicle drive device of the present invention is that it comprises a cooling plate through which a cooling fluid flows to cool electronic components for power conversion, an electric motor for vehicle operation, a case that houses the cooling plate and the electric motor, and a fastening member that fixes a stator having at least a coil portion of the electric motor to the case, and that insulating members are interposed at boundary positions where the stator and the fastening member, which are fastening objects, face each other in the fastening direction, and at boundary positions where the stator and the case face each other in the fastening direction.

[0012] According to this configuration, the temperature of the stator rises due to the supply of current to the coil when the electric motor is operating. Furthermore, heat insulating members are interposed at the boundary positions where the stator and the fastening member, which are fastening objects, face each other in the fastening direction, and at the boundary positions where the stator and the case face each other in the fastening direction. This prevents direct contact between the stator and the fastening member, and prevents heat from the stator from being transferred to the case via the fastening member. Furthermore, since the stator and the case do not come into direct contact, heat from the stator is not transferred to the case. In this way, heat transfer from the stator of the electric motor is suppressed, making it possible to utilize the heat from the stator. Therefore, a vehicle drive device capable of efficient heat utilization has been configured. [Brief explanation of the drawings]

[0013] [Figure 1] FIG. 2 is a cross-sectional view of a vehicle drive device. [Figure 2] FIG. 2 is a perspective view showing a case, a cooling plate, and a fastening bolt. [Figure 3] FIG. 2 is a cooling circuit diagram showing a cooling flow path through which a coolant flows. [Figure 4] 10 is a cross-sectional view of a fastening bolt for fixing the cooling plate to the case and a heat insulating member. FIG. [Figure 5] 4 is a cross-sectional view of a fastening bolt that fixes the stator to the case and a heat insulating member. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0014] Hereinafter, an embodiment of a vehicle drive device according to the present invention will be described with reference to the drawings. The present embodiment is not limited to the following embodiment, and various modifications are possible without departing from the spirit and scope of the present invention.

[0015] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. [Basic configuration] As shown in FIG. 1, the vehicle drive device A is configured with an aluminum case C, an electric motor M for driving and a gear reduction device G housed in a lower space S of the case C, and a control unit 1, an inverter 2, a cooling plate 3, and an oil cooler 4 housed in an upper space T of the case C.

[0016] This vehicle drive device A is configured to reduce the driving force of an electric motor M using a gear reduction device G and output it to left and right drive shafts 5. The vehicle drive device A is installed in a battery electric vehicle (BEV), but may also be installed in a hybrid electric vehicle (HEV), a plug-in hybrid electric vehicle (PHEV), a fuel cell electric vehicle (FCEV), etc.

[0017] The vehicle drive device A is mounted on the vehicle in the position shown in Fig. 1, with a pair of drive shafts 5 protruding laterally from the case C. In the following explanation, the up-down relationship, lateral positional relationship, etc. will be explained based on this position.

[0018] The case C has an intermediate wall Ca that divides the lower space S into left and right halves, and an electric motor M is housed in the left lower space SL on the left side of the intermediate wall Ca, with a left side plate 6 provided outside this. Also, a gear reduction device G is housed in the right lower space SR on the right side of the intermediate wall Ca, with a right side plate 7 provided outside this.

[0019] The left side plate 6 and the right side plate 7 are fixed to the case C by a plurality of side bolts 8. One drive shaft 5 penetrates the left side plate 6, and the other drive shaft 5 penetrates the right side plate 7.

[0020] The case C has a structure in which lubricating oil is stored in the bottom of the lower space S, and this lubricating oil is supplied to the gear reduction device G and the electric motor M. In particular, the electric motor M has a structure in which an annular stator Ma has a coil section in which multiple coils (U-phase, V-phase, and W-phase) are covered with resin, and a rotor Mb is housed inside the stator Ma so that it can rotate freely, and is lubricated and cooled by the supply of lubricating oil. In particular, the electric motor M has a cooling fluid L (see FIG. 3) supplied to a cooling passage 11 inside the stator Ma to dissipate heat from the coil section.

[0021] The stator Ma is made by laminating multiple electromagnetic steel plates and winding coils around multiple teeth formed on the inner periphery of the internal space of the stator Ma. The rotor Mb is rotatably housed in a space surrounded by the multiple teeth. Although not shown in the drawings, a flow path through which the cooling fluid L flows is formed near the teeth.

[0022] [Cooling circuit] 3, the cooling circuit includes a cooling flow path 11 through which a cooling fluid L flows, and a lubricating oil path 12 through which a lubricating oil flows. The cooling flow path 11 supplies the cooling fluid L supplied from outside the case C to the cooling plate 3, the stator Ma of the electric motor M, and the oil cooler 4 in that order, and then discharges it to the outside of the case C.

[0023] The vehicle drive device A circulates lubricating oil in a lubricating oil passage 12 in the order of oil pump P, oil cooler 4, electric motor M, and gear reduction device G. The oil cooler 4 dissipates heat from the lubricating oil through heat exchange, transferring heat from the lubricating oil to a cooling fluid L flowing in a cooling passage 11. The cooling fluid L may be a cooling water such as a long-life coolant (LLC) containing ethylene glycol or propylene glycol, or a paraffin-based insulating oil.

[0024] In order to dissipate heat from the rotor Mb of the electric motor M, a configuration may be adopted in which lubrication and cooling are performed by supplying lubricating oil without providing the cooling flow path 11. Even in such a configuration in which lubricating oil is used, the heat of the lubricating oil is transferred to the cooling fluid L in the oil cooler 4, and the heat of the electric motor M is transferred to the cooling fluid L.

[0025] [Configuration of the upper space] As shown in Figure 1, the upper space T of the case C is isolated from the lower space S and is open to the upper side. This upper space T is closed by a top plate 9. This top plate 9 is fixed to the case C by a plurality of top bolts 10.

[0026] The inverter 2 includes electronic components (power MOSFETs and IGBTs) that control the rotation speed of the electric motor M by controlling the power supplied to the coil of the electric motor M. The control unit 1 is configured as a unit that executes a preset program, and outputs control signals and the like that control the inverter 2 (including the electronic components).

[0027] The control unit 1 outputs a control signal to the inverter 2 based on information such as the amount of accelerator pedal depression, the torque acting on the driving system, and the actual driving speed, and drives the electric motor M with the required driving force to achieve controlled driving.

[0028] The inverter 2 generates heat during power control, and is therefore placed close to and above the cooling plate 3 to suppress temperature increases. The cooling plate 3 has a space inside it that allows the flow of cooling fluid L (see Figures 1 and 4), and removes heat from the inverter 2, thereby increasing the temperature of the cooling fluid L. The cooling plate 3 may also be placed in a position where it comes into contact with the inverter 2.

[0029] [Thermal insulation material] Taking a battery electric vehicle (BEV) as an example, since a battery vehicle does not have an internal combustion engine, a heat source is required to raise the temperature inside the cabin. Also, in hybrid vehicles and plug-in hybrid vehicles, the amount of heat that can be obtained from the internal combustion engine is reduced compared to vehicles with a constantly operating internal combustion engine, so a heat source is required to raise the temperature inside the cabin, and obtaining heat from the inverter 2 of the vehicle drive device A and the electric motor M becomes important.

[0030] Assuming that the heat from the inverter 2 and the electric motor M in the vehicle drive device A is used as a heat source, the heat from the inverter 2 can be extracted by the cooling fluid L flowing through the cooling plate 3. The heat from the electric motor M can be extracted by lubricating oil or the cooling fluid L flowing through the stator Ma. The inverter 2 and the electric motor M may also be collectively referred to as the "heat source."

[0031] Here, in order to efficiently acquire the heat from the heat source, it is important to suppress the heat loss caused by the heat from the heat source being transferred to the case C of the vehicle drive device A.

[0032] For this reason, as shown in Fig. 1, a heat insulating member 15 is used to suppress the amount of heat transferred from the cooling plate 3 and the electric motor M to the case C. This heat insulating member 15 is used at the location where the cooling plate 3 and the electric motor M are fastened to the case C using a plurality of fastening bolts 16 (an example of a fastening member / bolt). This heat insulating member 15 is made of a resin material with lower thermal conductivity than the case C and the fastening bolts 16, and is formed in a ring shape so that the fastening bolts 16 (an example of a fastening member / bolt) pass through, similar to a washer.

[0033] [Insulating material: Insulating cooling plate] 2 and 4, each of the multiple fastening bolts 16 (fastening members / bolts) includes a head 16a, a shaft portion 16b, and a threaded portion 16c. The threaded portion 16c is configured as a male screw, and is fastened by being screwed into a female threaded portion Cd formed in the case C.

[0034] The heat insulating member 15 is made of a resin with excellent heat insulating properties and is molded into an annular shape by integrally forming a cylindrical portion 15a, through which the shaft portion 16b of the fastening bolt 16 is inserted, and a flange portion 15b extending outward from the cylindrical portion 15a. In the heat insulating member 15, the inner surface of a hole 15c, which is the inner surface of the cylindrical portion 15a, contacts the outer surface of the shaft portion 16b of the fastening bolt 16, and a portion of the cylindrical portion 15a protrudes downward from the flange portion 15b. This protruding portion is sometimes referred to as the protruding portion.

[0035] 4, cooling plate 3 (an example of a fastening object) has plate hole 3a formed therein through which fastening bolt 16 is inserted, and also has plate-side fitting portion 3b formed on the upper surface thereof coaxially with plate hole 3a, into which protrusion (cylindrical portion 15a) of heat insulating member 15 is fitted. The inner diameter of plate hole 3a is larger than the outer diameter of shaft portion 16b of fastening bolt 16.

[0036] The case C also has a fitting recess Ce formed coaxially with the female screw portion Cd, into which the protruding portion (cylindrical portion 15a) of the heat insulating member 15 fits.

[0037] When the cooling plate 3 (object to be fastened) is fastened to the case C by the fastening bolt 16, the insulating member 15 is positioned at the boundary position where the cooling plate 3 and the head 16a of the fastening bolt 16 face each other in the fastening direction, and at the boundary position where the cooling plate 3 and the case C face each other in the fastening direction.

[0038] That is, the heat insulating members 15 are arranged at positions overlapping the plate hole portions 3a on the upper surface and the lower surface of the cooling plate 3. In this arrangement, the fastening bolts 16 are inserted through the heat insulating members 15 and the plate hole portions 3a of the cooling plate 3, and the threaded portions 16c of the fastening bolts 16 are screwed into the female threaded portions Cd of the case C, and then tightened to achieve a fastened state.

[0039] In particular, the upper heat insulation member 15 is referred to as the first heat insulation member 15X, and the lower heat insulation member 15 is referred to as the second heat insulation member 15Y. As shown in FIG. 4, the second thickness T2 (thickness in the direction along the bolt center Q) of the flange portion 15b of the second heat insulation member 15Y is set to be larger than the first thickness T1 (thickness in the direction along the bolt center Q) of the flange portion 15b of the first heat insulation member 15X (relationship of T1 < T2).

[0040] That is, the heat capacity of the case C is larger than the heat capacity of the head portion 16a of the fastening bolt 16. For this reason, the second thickness T2 of the flange portion 15b of the second heat insulation member 15Y that contacts the case C having a large heat capacity is made larger than the first thickness T1 of the flange portion 15b of the first heat insulation member 15X that contacts the head portion 16a having a small heat capacity. As a result, efficient heat loss is achieved without unnecessarily increasing the thickness of the heat insulation member.

[0041] Thus, the first heat insulation member 15X is interposed at the boundary position between the upper surface of the cooling plate 3 and the lower surface of the head portion 16a of the fastening bolt 16. Thereby, the head portion 16a of the fastening bolt 16 and the cooling plate 3 do not come into contact with each other, and the heat of the cooling plate 3 is not indirectly transmitted to the case C through the fastening bolt 16.

[0042] Also, the second heat insulation member 15Y is interposed at the boundary position between the lower surface of the cooling plate 3 and the upper surface of the case C. Thereby, the cooling plate 3 and the case C do not come into contact with each other, and the heat of the cooling plate 3 is not directly transmitted to the case C.

[0043] As shown in FIG. 4, in the fastened state, the protruding portion (cylindrical portion 15a) of the first heat insulation member 15X (upper heat insulation member 15) fits into the plate-side fitting portion 3b of the cooling plate 3, and the protruding portion (cylindrical portion 15a) of the second heat insulation member 15Y (lower heat insulation member 15) fits into the fitting recess Ce of the case C. Further, since the shaft portion 16b of the fastening bolt 16 fits into the hole portion 15c of the heat insulation member 15, the position of the heat insulation member 15 at the bolt center Q is determined, and as a result, the cooling plate 3 is fastened and fixed at an appropriate position.

[0044] Furthermore, in the fastened state, a gap is formed between the shaft-shaped portion 16b of the fastening bolt 16 and the inner periphery of the plate hole 3a of the cooling plate 3, and this gap blocks heat conduction.

[0045] In this way, by combining and fastening the fastening bolt 16 and the two insulating members 15, the phenomenon in which the heat of the cooling fluid L flowing through the cooling plate 3 is transferred to the case C is suppressed, and the temperature drop of the cooling fluid L is suppressed.

[0046] [Insulation material: insulation of electric motors] As shown in FIGS. 1 and 5, the electric motor M is fixed to the case C by screwing (fastening) the stator Ma into a female thread Cd formed in the case C with a plurality of fastening bolts 16 (fastening members / bolts).

[0047] The heat insulating member 15 and the fastening bolt 16 used for this fastening have the same shape as those used for fastening the cooling plate 3. The fastening bolt 16 for fastening the stator Ma is used in a horizontal position.

[0048] 5, the stator Ma (an example of an object to be fastened) has a stator hole Mh through which the fastening bolt 16 is inserted, and at its outer end (the left end in FIG. 5) has a stator-side fitting Mha formed coaxially with the stator hole Mh, into which the protruding portion (cylindrical portion 15a) of the heat insulating member 15 is fitted. The inner diameter of the stator hole Mh is larger than the outer diameter of the shaft-like portion 16b of the fastening bolt 16.

[0049] The case C has a fitting recess Ce formed coaxially with the female screw portion Cd, into which the protruding portion (cylindrical portion 15a) of the heat insulating member 15 fits.

[0050] When fastening the stator Ma (object to be fastened) to the case C with the fastening bolt 16, the insulating member 15 is positioned at the boundary position between the outer end side of the stator Ma and the head 16a of the fastening bolt 16, where they face each other in the fastening direction, and at the boundary position between the inner end side (the right end side in Figure 5) of the stator Ma and the case C, where they face each other in the fastening direction.

[0051] That is, the heat insulating member 15 is disposed at positions overlapping the stator hole portion Mh on the outer end side and the inner end side of the stator Ma. In this arrangement state, a fastening bolt 16 is inserted through the heat insulating member 15 and the stator hole portion Mh of the stator Ma, and the screw portion 16c of the fastening bolt 16 is screwed into the female screw portion Cd of the case C and tightened to reach a fastened state.

[0052] In this fastened state, the heat insulating member 15 on the outer end side is referred to as the first heat insulating member 15X, and the heat insulating member 15 on the inner end side is referred to as the second heat insulating member 15Y. As shown in FIG. 5, the second thickness T2 (thickness in the direction along the bolt center Q) of the flange portion 15b of the second heat insulating member 15Y is set larger than the first thickness T1 (thickness in the direction along the bolt center Q) of the flange portion 15b of the first heat insulating member 15X (relationship of T1 < T2).

[0053] In this way, the first heat insulating member 15X is interposed at the boundary position between the outer end side of the stator Ma and the head portion 16a of the fastening bolt 16. Thereby, the head portion 16a of the fastening bolt 16 and the stator Ma do not come into contact with each other, and the heat of the stator Ma is not indirectly transmitted to the case C through the fastening bolt 16.

[0054] Also, the second heat insulating member 15Y is interposed at the boundary position between the inner end side of the stator Ma and the case C. Thereby, the stator Ma and the case C do not come into contact with each other, and the heat of the stator Ma is not directly transmitted to the case C. <​​​​​​Furthermore, in the fastened state, a gap is formed between the shaft-shaped portion 16b of the fastening bolt 16 and the inner periphery of the stator hole Mh of the stator Ma, and this gap blocks heat conduction.

[0057] In this way, by combining and fastening the fastening bolt 16 with two insulating members 15, the phenomenon of heat from the stator Ma being transferred to the case C is suppressed, and the heat from the stator Ma can be transferred effectively to the cooling fluid L.

[0058] [Effects of the embodiment] The vehicle drive device A can efficiently increase the temperature of the cooling fluid L by suppressing heat dissipation caused by heat transfer from the inverter 2 and the electric motor M to the case C. This allows the inverter 2 and the electric motor M to be efficiently used as heat sources. Specifically, when attempting to increase the temperature inside the vehicle cabin, the heat of the cooling fluid L can be transferred to a heating device to increase the temperature inside the cabin, and there is no need to waste electricity as would be the case when using an electric heater, for example.

[0059] In addition, since the insulating member 15 is used to efficiently increase the heat of the cooling fluid L, by simply improving the system by using the insulating member 15 instead of the washer that was previously used, it is possible to suppress heat loss and increase the temperature of the cooling fluid L.

[0060] Furthermore, a first insulating member 15X and a second insulating member 15Y are used as the insulating member 15, and the second thickness T2 of the flange portion 15b of the first insulating member 15X is set to be thicker than the first thickness T1 of the flange portion 15b, and the second insulating member 15Y is positioned in abutment against the case C.

[0061] This makes it possible to suppress heat loss caused by heat transfer to the case C from the cooling plate 3 or the stator Ma of the electric motor M, which are fastened objects.

[0062] [Another embodiment] The present invention may be configured as follows in addition to the above-described embodiments (common numbers and symbols are used to designate components having the same functions as those in the embodiments).

[0063] (a) The shape of the heat insulating member 15 is not limited to that shown in the above embodiment, and may be a simple disk shape. Also, the heat insulating member 15 may have a structure in which a material with good heat insulating properties and a material with high strength are laminated to improve heat insulating properties while maintaining a certain level of strength.

[0064] (b) In the above-described embodiment, a part of the heat insulating member 15 configured as the first heat insulating member 15X may be formed integrally with the head 16a of the fastening bolt 16.

[0065] (c) A fastening bolt 16 and a nut can be used as the fastening member. For example, the nut can be made of a material with excellent insulating properties, or an insulating member 15 can be interposed at the boundary between the nut and the case C.

[0066] Furthermore, the configurations disclosed in the above embodiments (including other embodiments, the same applies below) can be applied in combination with configurations disclosed in other embodiments, as long as no contradictions arise. Furthermore, the embodiments disclosed in this specification are examples, and the embodiments of the present invention are not limited to these, and can be modified as appropriate within the scope that does not deviate from the purpose of the present invention.

[0067] In the above-described embodiment, the following configurations are envisioned. (1) A vehicle drive device comprising a cooling plate 3 through which a cooling fluid L for cooling electronic components (inverter 2) for power conversion flows, an electric motor M for vehicle travel, a case C for accommodating the cooling plate 3 and the electric motor M, and fastening members (fastening bolts 16) for fixing at least the cooling plate 3 to the case C, in which insulating members 15 are interposed at boundary positions where the cooling plate 3 and the fastening member (fastening bolts 16) as fastening objects face each other in the fastening direction, and at boundary positions where the cooling plate 3 and the case C face each other in the fastening direction.

[0068] According to this, the cooling plate 3 removes heat from the electronic components (inverter 2) for power conversion, thereby increasing the temperature of the cooling fluid L in the cooling plate 3. Furthermore, heat insulating members 15 are interposed at boundary positions where the cooling plate 3 and the fastening members (fastening bolts 16), which are fastening objects, face each other in the fastening direction, and at boundary positions where the cooling plate 3 and the case C face each other in the fastening direction. As a result, the cooling plate 3 and the fastening members (fastening bolts 16) that face each other in the fastening direction do not come into direct contact with each other, so heat from the cooling plate 3 is not transferred to the case C via the fastening members (fastening bolts 16). As the cooling plate 3 and the case C that face each other in the fastening direction do not come into direct contact with each other, heat from the cooling plate 3 is not transferred to the case C. Since a decrease in temperature of the cooling plate 3 is suppressed in this way, a decrease in the temperature of the cooling fluid L, whose temperature has increased in the cooling plate 3, can also be suppressed.

[0069] (2) A vehicle drive device comprising a cooling plate 3 through which a cooling fluid L for cooling electronic components (inverter 2) for power conversion flows, an electric motor M for vehicle travel, a case C for accommodating the cooling plate 3 and the electric motor M, and fastening members (fastening bolts 16) for fixing a stator Ma having at least the coil portion of the electric motor M to the case C, in which insulating members 15 are interposed at the boundary positions where the stator Ma and the fastening member (fastening bolts 16) as fastening objects face each other in the fastening direction, and at the boundary positions where the stator Ma and the case C face each other in the fastening direction.

[0070] According to this, the heat insulating member 15 is interposed at the boundary position where the stator Ma and the fastening member (fastening bolt 16) as fastening objects face each other in the fastening direction, and at the boundary position where the stator Ma and the case C face each other in the fastening direction. As a result, the stator Ma and the fastening member (fastening bolt 16) that face each other in the fastening direction do not come into direct contact with each other, so the heat of the stator Ma is not transferred to the case C via the fastening member (fastening bolt 16). Furthermore, the stator Ma and the case C that face each other in the fastening direction do not come into direct contact with each other, so the heat of the stator Ma is not transferred to the case C. In this way, the temperature drop of the stator Ma is suppressed, and therefore the temperature drop of the stator Ma can be suppressed.

[0071] (3) In the vehicle drive device A of (1) or (2), the fastening member (fastening bolt 16) is configured as a bolt (fastening bolt 16) having a head 16a, and the insulating member 15 is an annular body having a cylindrical portion 15a through which the bolt (fastening bolt 16) is inserted and a flange portion 15b extending outward from the cylindrical portion 15a, and is preferably configured of a first insulating member 15X arranged between the head 16a and the object to be fastened, and a second insulating member 15Y arranged between the object to be fastened and the case C.

[0072] According to this, a first heat insulating member 15X (heat insulating member 15) is interposed between a head 16a of the bolt (fastening bolt 16) and the cooling plate 3 or stator Ma as the fastening object, and a second heat insulating member 15Y (heat insulating member 15) is interposed between the cooling plate 3 or stator Ma as the fastening object and the case C. Because the head 16a of the bolt (fastening bolt 16) does not come into direct contact with the fastening object (cooling plate 3, stator Ma), heat from the fastening object (cooling plate 3, stator Ma) is not transferred to the case C via the fastening member (fastening bolt 16). Furthermore, because the fastening object (cooling plate 3, stator Ma) is not in direct contact with the case C, heat from the fastening object (cooling plate 3, stator Ma) is not transferred to the case C.

[0073] (4) In the vehicle drive device A of (3), it is preferable that the thickness T1 of the first heat insulating member 15X and the thickness T2 of the second heat insulating member 15Y are different in the axial direction of the bolt (fastening bolt 16).

[0074] According to this, for example, by varying the thickness of the insulating member based on the amount of heat transferred from the fastening object (cooling plate 3, stator Ma) to the head 16a of the bolt (fastening bolt 16) via the first insulating member 15X and the amount of heat transferred from the fastening object (cooling plate 3, stator Ma) to the case C via the second insulating member 15Y, heat loss can be suppressed without unnecessarily increasing the thickness of the insulating member.

[0075] In the vehicle drive device A of (5)(4), it is preferable that the thickness be made thicker on the side in contact with the larger heat dissipation capacity than on the side in contact with the smaller heat dissipation capacity, based on the relationship between the heat dissipation capacities of the head 16a and the case C.

[0076] This allows heat loss to be efficiently suppressed by using a thick insulating material to suppress heat transferred to the head 16a or case C with a larger heat capacity, and using a thin insulating material to suppress heat transferred to the head 16a with a smaller heat capacity. [Industrial Applicability]

[0077] The present invention can be used in a vehicle drive device. [Explanation of symbols]

[0078] 2: inverter (electronic component), 3: cooling plate, 15: heat insulating member, 15a: cylindrical portion, 15b: flange portion, 15X: first heat insulating member (heat insulating member), 15Y: second heat insulating member (heat insulating member), 16: fastening bolt (fastening member / bolt), 16a: head, C: case, M: electric motor, Ma: stator, T1: thickness of first heat insulating member, T2: thickness of second heat insulating member

Claims

1. a cooling plate through which a cooling fluid for cooling electronic components for power conversion flows; an electric motor for driving the vehicle; a case that houses the cooling plate and the electric motor; a fastening member that fastens at least the cooling plate to the case, A vehicle drive device in which an insulating member is interposed at a boundary position where the cooling plate and the fastening member, which are fastening objects, face each other in the fastening direction, and at a boundary position where the cooling plate and the case face each other in the fastening direction.

2. a cooling plate through which a cooling fluid for cooling electronic components for power conversion flows; an electric motor for driving the vehicle; a case that houses the cooling plate and the electric motor; a fastening member for fastening at least a stator having a coil portion of the electric motor to the case, A vehicle drive device in which a heat insulating member is interposed at a boundary position between the stator and the fastening member as fastening objects, where they face each other in the fastening direction, and at a boundary position between the stator and the case, where they face each other in the fastening direction.

3. The fastening member is configured as a bolt having a head, 3. The vehicle drive device according to claim 1, wherein the insulating member is an annular body having a cylindrical portion through which the bolt is inserted and a flange portion extending outward from the cylindrical portion, and is composed of a first insulating member arranged between the head and the object to be fastened, and a second insulating member arranged between the object to be fastened and the case.

4. 4. The vehicle drive device according to claim 3, wherein a thickness of the first heat insulating member and a thickness of the second heat insulating member are made different in an axial direction of the bolt.

5. 5. The vehicle drive device according to claim 4, wherein the thickness is determined based on the heat dissipation capacity relationship between the head and the case, with the portion in contact with the side with the larger heat dissipation capacity being thicker than the portion in contact with the side with the smaller heat dissipation capacity.

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