Electric vehicle drive device

Abstract

An electric vehicle driving device includes: a motor; a gear box that accommodates a speed reduction mechanism connected to the motor and a differential mechanism connected to the speed reduction mechanism; an inverter that is electrically connected to the motor and that converts electric power; the inverter has a first cooling water channel and a second cooling water channel through which cooling water flows, the oil cooler has an oil cooler water channel through which cooling water flows, the oil cooler is provided in contact with the inverter, and in the contact portion, the first cooling water channel is connected to the oil cooler water channel, and the second cooling water channel is connected to the oil cooler water channel. The second cooling water path is connected to the oil cooler water path, and forms a water path through which cooling water flows in the order of the first cooling water path, the oil cooler water path, and the second cooling water path.

Description

Technical Field

[0001] The present disclosure relates to an electric vehicle driving device. Background Art

[0002] In recent years, the replacement from vehicles powered by internal combustion engines driven by fuel supplied from a fuel tank to electric vehicles powered by electric motors driven by electricity supplied from a battery has been rapidly carried out. In addition, the concentration of on-board equipment used to drive electric vehicles is also developing. In the electric vehicle drive device that drives the electric vehicle, the main motor that generates power, the reducer that reduces the speed of the motor and transmits power to the axle, and the inverter that converts the DC current stored in the battery into an arbitrary AC current to effectively drive and control the motor are often integrated. Each of the motor, reducer and inverter generates loss during energy conversion or power transmission. The heat generated by the loss causes the local temperature of each device to rise. The excessive increase in the local temperature of each device becomes the cause of the failure of the electric vehicle drive device. Therefore, it is necessary to properly cool the electric vehicle drive device.

[0003] A general cooling structure for cooling an electric vehicle drive unit is composed of an oil cooling system in which oil circulates in the electric vehicle drive unit and an external water cooling system in which cooling water is supplied from the outside to an oil cooler that is a part of the oil cooling system (for example, Patent Document 1). In the oil cooling system, the oil retained in the lower part of the housing that accommodates the reducer is supplied to the heat generating part through the oil cooler and one or more oil passages by an oil pump. By directly or indirectly bringing the heat generating part into contact with the oil, the oil absorbs heat and cools the heat generating part, and the high-temperature oil flows back to the lower part of the housing again. The external water cooling system is a structure in which a radiator, a cooling water pump, a water cooling plate of an inverter, and an oil cooler are connected by piping. The cooling water in the external water cooling system circulates by the operation of the cooling water pump.

[0004] By configuring in this way, cooling water is supplied to the oil cooler from the external water cooling system, and the high-temperature oil circulating in the oil cooling system exchanges heat with the cooling water through the oil cooler, thereby enabling the low-temperature oil to be supplied to the heat generating part. On the other hand, in the external water cooling system, the cooling water absorbs heat from the high-temperature oil in the oil cooler, and the high-temperature cooling water releases heat to the surrounding air in the radiator. The low-temperature cooling water sent from the radiator is again supplied to the oil cooler. In the oil circulation of these oil cooling systems and the cooling water circulation of the external water cooling system, heat is transported from the heat generating part of the electric vehicle drive device to the radiator via the oil and cooling water, and heat is released from the radiator to the surrounding air.

[0005] The specific structure of the part of the electric vehicle drive device provided with an oil cooler is disclosed (for example, patent document 2). In the structure of the disclosed electric vehicle drive device, in order to efficiently perform heat exchange, a rectangular parallelepiped oil cooler in which the oil circuit and the cooling water circuit alternately overlap is provided obliquely above the motor. Two oil circuit connecting parts are provided on the surface where the motor contacts the oil cooler. Two L-shaped joints are installed on the surface on the opposite side of the oil cooler, and a hose for passing cooling water is connected to the joint to form a pipe for the flow of cooling water. By configuring in this way, cooling water can be passed to the pipe of the hose, and oil can be supplied from the oil circuit connecting part by an oil pump provided separately, so that heat exchange between oil and cooling water can be effectively performed via the solid wall in the oil cooler that separates the oil circuit and the cooling water circuit. Through heat exchange, low-temperature oil is sent out from the oil circuit connecting part of the oil cooler, and the low-temperature oil is supplied to the heat generating part of the electric vehicle drive device, so that the heat generating part can be cooled.

[0006] A specific other structure of a portion of an electric vehicle drive device provided with an oil cooler is disclosed (e.g., Patent Document 3). In the disclosed structure of the electric vehicle drive device, an oil cooler is housed in a gear box that houses a reduction mechanism and a differential mechanism. By configuring in this way, in the electric vehicle drive device, the protruding portion of the oil cooler itself disappears, thereby enabling the electric vehicle drive device to be miniaturized. In addition, the electric vehicle drive device can be easily assembled into an electric vehicle. [Prior art literature] [Patent Document]

[0007] Patent Document 1: Japanese Patent No. 7140727 Patent Document 2: Japanese Patent No. 7278845 Patent Document 3: Japanese Patent Laid-Open No. 2000-295818 Summary of the invention

[0008] In the above-mentioned Patent Document 2, the oil and cooling water can be effectively heat-exchanged in the oil cooler, and the heat-generating part of the electric vehicle drive device can be cooled by the low-temperature oil sent from the oil circuit connection part of the oil cooler. However, in the electric vehicle drive device, since it is installed as a protruding structure of the oil cooler, the connector for cooling water is further extended, and space is required around the connector for retrieving the hose used as the piping. Therefore, the volumetric efficiency of the electric vehicle drive device is very poor, and there is a technical problem of enlarging the electric vehicle drive device. In addition, there is a technical problem that the electric vehicle drive device cannot be easily assembled into the electric vehicle.

[0009] In the above-mentioned Patent Document 3, since the oil cooler is accommodated in the gear box, the electric vehicle drive device can be miniaturized and easily assembled into the electric vehicle. However, although the protruding part of the oil cooler itself disappears, since the joint for cooling water protrudes around the oil cooler and a space is required around the oil cooler for retrieving the hose as the piping, the volumetric efficiency of the electric vehicle drive device is poor, and there is a technical problem of enlarging the electric vehicle drive device. In addition, the interior of the gear box requires a waterproof structure for preventing the components from rusting, but in the above-mentioned Patent Document 3, since the cooling water channel is accommodated in the gear box, there is a technical problem that the cooling water intrudes into the interior of the gear box which is a waterproof area of ​​the electric vehicle drive device. In the case where the cooling water intrudes into the interior of the gear box, the interior of the gear box may rust. In addition, since there is no drainage function from the inside of the gear box to the outside in the gear box, the cooling water may also intrude into the interior of the motor. In the case where the cooling water intrudes into the interior of the motor, the insulation breakdown of the wiring part and the stator coil in the motor caused by the cooling water may cause a greater failure of the electric vehicle drive device.

[0010] Therefore, an object of the present disclosure is to obtain an electric vehicle driving device that does not require piping around an oil cooler, is lightweight and compact, does not allow cooling water to enter a waterproof area, and is easy to assemble into an electric vehicle.

[0011] The electric vehicle drive device disclosed in the present invention includes: an electric motor; a gear box, which accommodates a reduction mechanism connected to the electric motor and a differential mechanism connected to the reduction mechanism; an inverter, which is electrically connected to the electric motor and converts electric power; and an oil cooler, which performs oil cooling on the electric motor, the inverter having a first cooling water path and a second cooling water path for cooling water to flow, the oil cooler having an oil cooler water path for cooling water to flow, the oil cooler being arranged in contact with the inverter, and in the contact portion, the first cooling water path is connected to the oil cooler water path, and the second cooling water path is connected to the oil cooler water path, forming a water path for cooling water to flow in the order of the first cooling water path, the oil cooler water path, and the second cooling water path.

[0012] According to the electric vehicle drive device disclosed in the present invention, the inverter has a first cooling water path and a second cooling water path for cooling water to flow, and the oil cooler has an oil cooler water path for cooling water to flow. The oil cooler is arranged to abut the inverter. In the abutting portion, the first cooling water path is connected to the oil cooler water path, and the second cooling water path is connected to the oil cooler water path, forming a water path for cooling water to flow in the order of the first cooling water path, the oil cooler water path, and the second cooling water path. Therefore, around the oil cooler, especially in the part between the inverter and the oil cooler, no piping for the water path for cooling water to flow is required, so that the electric vehicle drive device can be made lightweight and miniaturized. In addition, since the water path for cooling water to flow is not provided inside the gear box as the waterproof area of ​​the electric vehicle drive device, the cooling water can be suppressed from invading the waterproof area. In addition, since no piping is provided around the oil cooler, there is no part of the piping protruding around the oil cooler, so there is no need for troublesome piping work and piping retrieval space, and an electric vehicle drive device that is easy to assemble to an electric vehicle can be obtained. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 This is a plan view schematically showing the electric vehicle driving device according to the first embodiment. Figure 2 This is a front view schematically showing the electric vehicle driving device according to the first embodiment. Figure 3 This is a side view schematically showing the electric vehicle driving device according to the first embodiment. Figure 4 This is an exploded plan view showing the main parts of the electric vehicle driving device according to the first embodiment. Figure 5 This is a side view showing a main part of the electric vehicle driving device according to the first embodiment. Figure 6 This is an exploded plan view showing the main parts of another electric vehicle driving device according to the first embodiment. Figure 7 This is a side view showing a main part of another electric vehicle driving device according to the first embodiment. Figure 8 This is an exploded plan view showing the main parts of another electric vehicle driving device according to the first embodiment. Fig. 9 This is a side view showing a main part of another electric vehicle driving device according to the first embodiment. Fig.10 It is a side view showing the main part of the electric vehicle driving device according to the second embodiment. Fig.11 It is a plan view showing the main part of the electric vehicle driving device according to the second embodiment. Fig.12 It is a side view showing the main part of the electric vehicle driving device according to the third embodiment. Fig.13 It is a plan view showing the main part of the electric vehicle driving device according to the third embodiment. Fig.14 This is a cross-sectional view showing a main part of an electric vehicle driving device according to a fourth embodiment. Fig.15 This is a cross-sectional view showing a main part of another electric vehicle driving device according to the fourth embodiment. Fig.16 This is a cross-sectional view showing a main part of another electric vehicle driving device according to the fourth embodiment. Explanation of symbols 1 Electric vehicle drive device, 2 Oil cooler, 2a, 2a1, 2a2 Oil cooler water path, 2b Oil cooler oil path, 2c Main body, 2c1 Side, 3 Electric motor, 3a Rotating shaft, 3b Rotor, 3c Housing, 3d Stator, 4 Speed ​​reduction mechanism, 5 Differential mechanism, 6 Gear box, 6a Drive shaft, 7 Inverter, 8 Oil cooler oil path connection part, 8a First oil cooler oil path connection part, 8b Second oil cooler oil path connection part, 9 Oil cooler water path connection part, 10 Oil path, 10a, 10b Plate oil path, 11, 11a, 11b Oil path connection part, 12 Water cooling plate, 12a Cooling surface, 13a First cooling water path, 13 b second cooling water channel, 13b1 second cooling water channel connecting portion, 14a, 14b cooling water channel connecting portion, 15 electrical components, 16a housing, 16b cover, 17 cooling water inlet portion, 18 cooling water outlet portion, 19 oil header, 20 cooling water header, 21 protrusion, 22, 22a, 22b end plate, 22a1 end plate water channel, 22b1 end plate oil channel, 23 joint, 24 O-ring, 25 power module, 26 capacitor, 27a, 27b first plate oil channel connecting portion, 28a, 28b second plate oil channel connecting portion, 29 opening, 30 cooling water pump, 31 power conversion mechanism, 32, 32a, 32b gear. DETAILED DESCRIPTION

[0014] Hereinafter, an electric vehicle drive device according to an embodiment of the present disclosure will be described based on the accompanying drawings. In addition, the same or equivalent components and parts are marked with the same symbols in each figure for description. In addition, the electric vehicle in the present disclosure is not limited to an automobile, but refers to a mobile body used in traffic, transportation, mobile mechanism, etc. including a two-wheeled vehicle.

[0015] Implementation Method 1 Figure 1 (a) is a plan view showing an outline of the electric vehicle driving device 1 according to the first embodiment, Figure 1(b) is a plan view showing the outline of the electric vehicle driving device 1 by removing the drive shaft 6a from the electric vehicle driving device 1. Figure 1 (c) is a plan view showing an outline of another electric vehicle driving device 1, Figure 2 1 is a front view showing an outline of the electric vehicle driving device 1, and is a view viewed from the traveling direction of the electric vehicle. Figure 3 1 is a side view showing the outline of the electric vehicle driving device 1 and is a view showing the other side in the X direction. Figure 4 is an exploded top view showing the main parts of the electric vehicle driving device 1. Figure 2 FIG. 1 is a diagram showing the installation structure of the oil cooler 2 at the A portion (the portion surrounded by the dotted line), Figure 5 (a) is a side view showing a main part of the electric vehicle driving device 1, and is a view showing the oil cooler 2 and the water cooling plate 12 through both and viewed from the other side in the X direction. Figure 5 (b) is a side view showing a main part of another electric vehicle driving device 1, and is viewed from the same direction as Figure 5 The same part of (a) is shown in Figure 1. Figure 5 (c) is a side view showing the main part of another electric vehicle driving device 1, and is viewed from the same direction as Figure 5 The same part of (a) is shown in Figure 1. Figure 6 is an exploded top view showing the main parts of another electric vehicle driving device 1, and is a view showing Figure 2 FIG. 2 is a diagram showing the installation structure of the oil cooler 2 at the same position as part A. Figure 7 is a side view showing a main part of another electric vehicle driving device 1, and is viewed from the other side in the X direction. Figure 6 The picture, Figure 8 is an exploded top view showing the main parts of another electric vehicle driving device 1, and is a view showing Figure 2 FIG. 2 is a diagram showing the installation structure of the oil cooler 2 at the same position as part A. Fig. 9 is a side view showing a main part of another electric vehicle driving device 1, and is viewed from the other side in the X direction. Figure 8 The electric vehicle driving device 1 mounted on the electric vehicle is a device that transmits the rotation of the rotating shaft 3a of the electric motor 3 controlled by the inverter 7 to the driving shaft 6a via the speed reduction mechanism 4 and the differential mechanism 5.

[0016] <Electric vehicle driving device 1> like Figure 1As shown in (b), the electric vehicle driving device 1 includes: an electric motor 3; a gear box 6 that accommodates a reduction mechanism 4 connected to the electric motor 3 and a differential mechanism 5 connected to the reduction mechanism 4; an inverter 7 that is electrically connected to the electric motor 3 and converts electric power; and an oil cooler 2 that performs oil cooling on the electric motor 3. Here, the direction is defined. Figure 1 (a) and Figure 2 In the embodiment, the direction in which the oil cooler 2 and the inverter 7 are arranged is set to one side of the X direction. Figure 1 (a) and Figure 3 In the figure, the direction perpendicular to the X direction and in which the motor 3 is provided relative to the inverter 7 is set as one side of the Y direction, and the direction perpendicular to the X direction and the Y direction is set as the Z direction. In each figure, the direction indicated by the arrow is set as one side, and the opposite direction of the direction indicated by the arrow is set as the other side.

[0017] A gear box 6 is provided on one side of the motor 3 and the oil cooler 2 in the X direction. Figure 1 As shown in (a), the motor 3 and the gear box 6 are connected in an L shape. The oil cooler 2 and the inverter 7 are provided on the other side of the portion between the motor 3 and the gear box 6 arranged in the L shape in the Z direction. The configuration of the components in the electric vehicle drive device 1 is not limited to the above configuration. As described later, any configuration in which the oil cooler 2 and the inverter 7 are arranged in contact with each other may be used. Figure 1 As shown in (c) , the oil cooler 2 may be provided on one side of the inverter 7 in the Y direction, and the oil cooler 2 may be sandwiched between the inverter 7 and the motor 3 .

[0018] like Figure 1 As shown in (b), the motor 3 includes a stator 3d having an iron core and a coil, a rotor 3b arranged inside the stator 3d, and a housing 3c accommodating the stator 3d and the rotor 3b. The rotating shaft 3a of the rotor 3b is supported by a bearing so as to be freely rotatable, and is arranged so as to be coaxially rotatable relative to the stator 3d. The housing 3c is made by casting or forging a metal such as aluminum, for example.

[0019] The gearbox 6 accommodates the speed reduction mechanism 4 connected to the rotating shaft 3a and the differential mechanism 5 connected to the speed reduction mechanism 4. The speed reduction mechanism 4 reduces the speed of the rotating shaft 3a of the motor 3 and outputs it. The differential mechanism 5 absorbs the speed difference between the left and right tires. The gearbox 6 is made by casting or forging a metal such as aluminum, for example.

[0020] One side of the drive shaft 6a is connected to the differential mechanism 5. The drive shaft 6a extends in the X direction. Tires (not shown) are installed in the parts on both sides of the extension of the drive shaft 6a. By using aluminum to make the housing 3c and the gear box 6, they can be made lightweight and low-cost, and complex shapes can also be easily made. In addition, by making these parts from the same material, it can be a countermeasure for electrical corrosion. In addition, the material of these parts is not limited to aluminum, and can also be a resin material.

[0021] <Inverter 7, oil cooler 2> The structures of the inverter 7 and the oil cooler 2, which are the main parts of the present disclosure, are described. The inverter 7 performs direct current to alternating current conversion between a direct current power source (not shown) and the windings of the multi-phase stator 3d. The inverter 7 is fixed to the motor 3, for example. Figure 1 As shown in (b) of FIG. 7 , the inverter 7 includes a first cooling water passage 13 a and a second cooling water passage 13 b through which cooling water flows.

[0022] The oil cooler 2 includes an oil cooler water passage 2a through which cooling water flows and an oil cooler oil passage 2b through which oil flows. Figure 1 (b) schematically shows these components. The oil cooler water path 2a and the oil cooler oil path 2b are arranged in isolation without being connected. The oil cooler 2 is an oil-cooling water heat exchanger in which the oil cooler water path 2a and the oil cooler oil path 2b perform heat exchange via a solid wall. The oil cooler water path 2a and the oil cooler oil path 2b are, for example, Figure 4 As shown in the alternate stacking configuration. Figure 5 As shown in (a), the oil cooler 2 has an oil header 19 and a cooling water header 20 on both sides of the Y direction. The stacked oil cooler water path 2a is connected to the cooling water header 20 to form a flow path connected in parallel. The stacked oil cooler oil path 2b is connected to the oil header 19 to form a flow path connected in parallel. The motor 3 and the gear box 6 have an oil path 10 connected to the oil cooler oil path 2b. For example, water can be used as the cooling water, but it is not limited to this. Antifreeze (LLC) containing ethylene glycol as a main component can also be used.

[0023] like Figure 1 As shown in (b), the oil cooler 2 is disposed in contact with the inverter 7. In the contact portion, the first cooling water path 13a is connected to the oil cooler water path 2a, and the second cooling water path 13b is connected to the oil cooler water path 2a. A water path is formed for cooling water to flow in the order of the first cooling water path 13a, the oil cooler water path 2a, and the second cooling water path 13b. Figure 2 As shown, the portion of the inverter 7 that the oil cooler 2 abuts against is the portion of the inverter 7 where the first cooling water passage 13 a and the second cooling water passage 13 b are formed, that is, the water cooling plate 12 .

[0024] By configuring in this way, since piping for the water path for cooling water to flow is not required around the oil cooler 2, especially in the portion between the inverter 7 and the oil cooler 2, the electric vehicle drive device 1 can be made lightweight and compact. In addition, since no water path for cooling water to flow is provided inside the gear box 6, which is the waterproof area of ​​the electric vehicle drive device 1, the intrusion of cooling water into the waterproof area can be suppressed. In addition, since no piping is provided around the oil cooler 2, there is no protruding portion of piping around the oil cooler 2, and therefore, there is no need for cumbersome piping work and space for retrieving the piping, and the electric vehicle drive device 1 that is easy to assemble into the electric vehicle can be obtained. In addition, since there is no protruding portion of piping around the oil cooler 2, the volumetric efficiency of the electric vehicle drive device 1 can be improved.

[0025] In this embodiment, the oil cooler 2 is disposed in contact with the motor 3 or the gear box 6 on the side opposite to the inverter 7. In the contact portion, the oil passage 10 is connected to the oil cooler oil passage 2b. The oil cooler 2 is disposed so as to be sandwiched between the inverter 7 and the motor 3 or the gear box 6. Figure 2 In the structure shown, the oil cooler 2 is sandwiched between the inverter 7 and the gear box 6. Figure 1 In the structure shown in (c), the oil cooler 2 is arranged to be sandwiched between the inverter 7 and the motor 3 .

[0026] By configuring in this way, there is no need for piping for the water path for cooling water to flow around the oil cooler 2, especially in the portion between the inverter 7 and the oil cooler 2, and there is no need for piping for the oil path for oil to flow between the motor 3 or the gear box 6 and the oil cooler 2, so that the electric vehicle drive device 1 can be made lighter and smaller. In addition, since there is no piping around the oil cooler 2, there is no portion where the piping protrudes around the oil cooler 2, and thus there is no need for troublesome piping work and space for retrieving the piping, and the electric vehicle drive device 1 that is easy to assemble into the electric vehicle can be obtained. In addition, since there is no portion where the piping protrudes around the oil cooler 2, the volumetric efficiency of the electric vehicle drive device 1 can be improved.

[0027] use Figure 4An example of the mounting structure of the oil cooler 2 is described. Two oil cooler oil circuit connecting parts 8 are provided on one side of the oil cooler 2 in the X direction, and two oil cooler water circuit connecting parts 9 are provided on the other side of the oil cooler 2 in the X direction. The oil cooler oil circuit connecting part 8 is the end of the oil cooler oil circuit 2b. The oil cooler water circuit connecting part 9 is the end of the oil cooler water circuit 2a. The oil circuit 10 of the gear box 6 has two oil circuit connecting parts 11 on the other side of the X direction. The oil circuit connecting part 11 is the end of the oil circuit 10. The first cooling water circuit 13a has a cooling water circuit connecting part 14a as the end of the first cooling water circuit 13a on the other side of the X direction, and the second cooling water circuit 13b has a cooling water circuit connecting part 14b as the end of the second cooling water circuit 13b on the other side of the X direction.

[0028] Each of the oil cooler oil circuit connection parts 8 is connected to each of the oil circuit connection parts 11. Through these connections, the oil cooler oil circuit 2b is connected to the oil circuit 10, the gear box 6 and the oil cooler 2 are in contact, and the oil cooler 2 is fixed to the gear box 6. One side of the oil cooler water circuit connection part 9 is connected to the cooling water circuit connection part 14a, and the other side of the oil cooler water circuit connection part 9 is connected to the cooling water circuit connection part 14b. Through these connections, the oil cooler water circuit 2a is connected to the first cooling water circuit 13a and the second cooling water circuit 13b, the inverter 7 is in contact with the oil cooler 2, and the oil cooler 2 is fixed to the inverter 7.

[0029] In the present embodiment, a joint 23 is provided as the oil cooler oil circuit connection part 8 and the oil cooler water circuit connection part 9. A recessed part that fits with the joint 23 is provided in the oil circuit connection part 11, the cooling water circuit connection part 14a, and the cooling water circuit connection part 14b. By connecting these connection parts by using a fitting structure, the deviation of the in-plane direction of the abutting surface can be reduced, thereby facilitating the fixing of the two abutting components. The first cooling water circuit 13a and the oil cooler water circuit 2a, the second cooling water circuit 13b and the oil cooler water circuit 2a, and the oil circuit 10 and the oil cooler oil circuit 2b can also be connected by a one-touch connector structure. As Figure 4 As shown in the interlocking structure on the lower right side of the one-touch connector structure, one side to be connected is a socket and the other side is a plug. A liquid outflow prevention mechanism with a check valve or the like to simplify disassembly is provided in the connector 23 on the plug side. The liquid outflow prevention mechanism can also be an O-ring. By configuring in this way, when the oil cooler 2 is disassembled or replaced, the outflow of oil or cooling water can be suppressed, and garbage can be prevented from mixing into the oil cooler water path 2a or the oil cooler oil path 2b. In addition, the assemblability of the electric vehicle drive device 1 can be improved.

[0030] The structure of the inverter 7 is described in detail. Figure 2As shown, the inverter 7 has an electrical component 15 and a water-cooled plate 12 having a first cooling water path 13a and a second cooling water path 13b formed inside. The electrical component 15 is an electrical / electronic component group that converts electric power and drives and controls the motor 3. The electrical component 15 is mounted on the water-cooled plate 12. The electrical component 15 is surrounded by a shell 16a formed in a cylindrical shape. The opening portion on the other side of the Z direction of the shell 16a abuts against the water-cooled plate 12. The opening portion on one side of the Z direction of the shell 16a is covered by a cover 16b. The electrical component 15 is waterproofed from the outside by the shell 16a and the cover 16b, and is insulated from the outside and protected. The shell 16a and the cover 16b are made of metal such as aluminum, for example.

[0031] The inverter 7 has a cooling water inlet 17 for allowing cooling water to flow into the first cooling water path 13a and a cooling water outlet 18 for allowing cooling water to be sent out from the second cooling water path 13b. Figure 1 As shown in (a), the cooling water inlet 17 and the cooling water outlet 18 are provided on the other side of the water cooling plate 12 in the X direction. The configuration of the cooling water inlet 17 and the cooling water outlet 18 is not limited thereto, and they may be provided on the other side of the water cooling plate 12 in the Z direction, for example.

[0032] The cooling water inlet 17 and the cooling water outlet 18 are connected to an external water cooling system. Low-temperature cooling water is supplied to the cooling water inlet 17 from the external water cooling system. The external water cooling system is composed of, for example, a radiator and a cooling water pump, and the cooling water in the external water cooling system circulates in the first cooling water path 13a, the oil cooler water path 2a, and the second cooling water path 13b by the operation of the cooling water pump. When the cooling water flows through the first cooling water path 13a and the second cooling water path 13b, the heat generated by the operation of the electrical component 15 is absorbed by the cooling water through the solid wall of the water-cooled plate 12. The cooling water heated by absorbing heat is discharged from the cooling water outlet 18. The heated cooling water dissipates heat to the surrounding air in the radiator.

[0033] The cooling water inlet 17 and the cooling water outlet 18 are, for example, joints, and are connected to the piping of the external water cooling system via a sealing structure such as an O-ring or a gasket. The cooling water inlet 17 and the cooling water outlet 18 are connected to the external water cooling system via piping, and the installation position and structure are not limited to the above structure as long as it is a structure for supplying or discharging cooling water. In addition, the cooling water is not limited to the structure discharged from the cooling water outlet 18 to the external water cooling system, and the cooling water can also be sent from the cooling water outlet 18 to the motor 3 or other equipment (charger or booster, etc.) to cool the motor 3 or other equipment.

[0034] use Figure 5 (a) to Figure 5(c) of FIG. 1 shows a detailed description of the connection structure between the inverter 7 and the oil cooler 2. In these figures, the electrical components 15 are indicated by a single-dot chain line, the oil cooler water path 2a is indicated by a dotted line, and the oil cooler oil path 2b is indicated by a dotted line. Figure 5 In (a), the oil header 19 and the cooling water header 20 are arranged in the same order in the Y direction. The oil cooler water passage 2a and the oil cooler oil passage 2b stacked in the X direction are formed to extend in the Z direction when viewed in the X direction. Figure 5 In (b), the oil header 19 and the cooling water header 20 are arranged in reverse order so that the oil header 19 and the cooling water header 20 are arranged in the Y direction. The oil cooler water path 2a and the oil cooler oil path 2b stacked in the X direction are formed to extend obliquely so that their respective flow paths intersect when viewed in the X direction. When the first cooling water path 13a and the second cooling water path 13b are arranged on the same plane, Figure 5 In the structure of the oil cooler 2 shown in (a), the oil cooler 2 and the inverter 7 can be arranged in the XY plane. Figure 5 In the structure of the oil cooler 2 shown in (b), the inverter 7 is arranged to be inclined with respect to the oil cooler 2 in the XY plane. Figure 5 The oil cooler 2 shown in (b) is excellent in heat exchange efficiency between oil and cooling water, but since the inverter 7 is arranged at an angle, the volumetric efficiency of the oil cooler 2 and the inverter 7 is deteriorated.

[0035] right Figure 5 Another structure shown in (c) is described below. Figure 5 In (c), the structure of the oil cooler 2 is Figure 5 The structure of the oil cooler 2 shown in (b) is the same as that of the water cooling plate 12. Figure 5 (b) is different. The water-cooled plate 12 has a protrusion 21 protruding along the Z direction from the cooling surface 12a on which the electrical component 15 is installed. The protrusion 21 has a second cooling water path connecting portion 13b1 connected to the second cooling water path 13b. The second cooling water path connecting portion 13b1 and the cooling water header 20 are connected in the oil cooler water path connecting portion 9. Through the second cooling water path 13b, the second cooling water path connecting portion 13b1 and the cooling water header 20, an S-shaped flow path is formed when viewed from the Y direction, and both the oil cooler 2 and the inverter 7 can be arranged in the XY plane. By configuring in this way, even if the heat exchange efficiency between the oil and the cooling water is good, Figure 5 The oil cooler 2 with the flow path structure of (b) can also arrange both the oil cooler 2 and the inverter 7 in the XY plane, so that the oil cooler 2 and the inverter 7 can be arranged with good volumetric efficiency.

[0036] <Variation 1> use Figure 6 and Figure 7 , the structure of variation 1 is described. Figure 6 As shown, the oil cooler 2 has an end plate 22 on the side where the inverter 7 is provided on the other side in the X direction. The end plate 22 has two oil cooler water channel connecting parts 9 on the other side in the X direction. The oil cooler water channel connecting part 9 is, for example, a joint 23. The end plate 22 has an end plate water channel 22a1 inside that connects the first cooling water channel 13a and the second cooling water channel 13b to the oil cooler water channel 2a. The end plate water channel 22a1 is bent into an S shape along the X direction inside the end plate 22 to connect to the oil cooler water channel 2a. Figure 5 (c) Similarly, it is possible to realize the arrangement of the oil cooler 2 and the inverter 7 with good volumetric efficiency.

[0037] In the first modification, the motor 3 is provided on the other side of the oil cooler 2 in the X direction. The oil cooler 2 has a first oil cooler oil passage connection portion 8a on one side in the X direction and a second oil cooler oil passage connection portion 8b on the other side in the X direction. Figure 6 In the figure, the second oil cooler oil circuit connection part 8b is located on the other side of the oil cooler water circuit connection part 9 in the Z direction, so it is not shown. The first oil cooler oil circuit connection part 8a is connected to the oil circuit connection part 11a of the gear box 6, and the second oil cooler oil circuit connection part 8b is connected to the oil circuit connection part 11b of the motor 3. The oil flows through the gear box 6, the oil cooler 2, and the motor 3 in sequence. Figure 7 As shown, the electric vehicle driving device 1 may be configured such that the motor 3 is disposed on the other side of the oil cooler 2 in the X direction and the oil flows through the gear box 6, the oil cooler 2, and the motor 3 in sequence.

[0038] <Variation 2> use Figure 8 and Fig. 9 , the structure of variation 2 is described. Figure 8 As shown, the oil cooler 2 has end plates 22 on both sides, one side in the X direction and the other side in the X direction. The end plate 22 disposed on the other side in the X direction is the end plate 22a, and the end plate 22 disposed on one side in the X direction is the end plate 22b. As the structure of the water channel inside the end plate 22a, the end plate 22a has two end plate water channels 22a1. The end plate water channel 22a1 on the other side in the Y direction is an end plate water channel 22a1 bent into an S shape along the X direction. The connection between the end plate 22a and the first cooling water channel 13a and the second cooling water channel 13b disposed in the water-cooled plate 12 is not through a joint, but is ensured to be liquid-tight by abutting with an O-ring 24 interposed therebetween.

[0039] The end plate 22b is provided with two oil cooler oil circuit connection parts 8 on one side in the X direction. The oil cooler oil circuit connection part 8 is a part that ensures liquid tightness by abutting against the oil circuit connection part 11 with the O-ring 24. The end plate 22b has two end plate oil circuits 22b1 that connect the oil circuit 10 of the gear box 6 with the oil cooler oil circuit 2b inside. By bending the end plate oil circuit 22b1 on one side in the Y direction in the end plate 22b in the same S-shape along the X direction as the end plate water circuit 22a1 on the other side in the Y direction of the end plate 22a inside the end plate 22b, the oil circuit connection parts 11 are arranged in the Y direction, so that the configuration of the oil cooler 2 and the gear box 6 with good volumetric efficiency can be achieved.

[0040] As described above, in the electric vehicle driving device 1 of the first embodiment, the inverter 7 has the first cooling water path 13a and the second cooling water path 13b for cooling water to flow, and the oil cooler 2 has the oil cooler water path 2a for cooling water to flow. The oil cooler 2 is provided to abut against the inverter 7, and in the abutting portion, the first cooling water path 13a is connected to the oil cooler water path 2a, and the second cooling water path 13b is connected to the oil cooler water path 2a, forming a water path for cooling water to flow in the order of the first cooling water path 13a, the oil cooler water path 2a, and the second cooling water path 13b. Therefore, around the oil cooler 2, especially in the portion between the inverter 7 and the oil cooler 2, no piping for the water path for cooling water to flow is required, so that the electric vehicle driving device 1 can be made lighter and smaller. In addition, since the water path for cooling water to flow is not provided inside the gear box 6, which is the waterproof area of ​​the electric vehicle driving device 1, the intrusion of cooling water into the waterproof area can be suppressed. In addition, since no piping is provided around the oil cooler 2, there is no protruding portion of the piping around the oil cooler 2, so that troublesome piping work and piping retrieval space are not required, and the electric vehicle drive device 1 that is easy to assemble into the electric vehicle can be obtained. In addition, since there is no protruding portion of the piping around the oil cooler 2, the volumetric efficiency of the electric vehicle drive device 1 can be improved.

[0041] The oil cooler 2 is disposed in contact with the motor 3 or the gearbox 6 on the side opposite to the inverter 7. In the contact portion, the oil passage 10 is connected to the oil cooler oil passage 2b. When the oil cooler 2 is sandwiched between the inverter 7 and the motor 3 or the gearbox 6, since there is no need for piping of a water passage for cooling water to flow around the oil cooler 2, especially in the portion between the inverter 7 and the oil cooler 2, and there is no need for piping of an oil passage for oil to flow in the portion between the motor 3 or the gearbox 6 and the oil cooler 2, the electric vehicle drive device 1 can be made lighter and smaller. In addition, since there is no piping around the oil cooler 2, there is no portion where the piping protrudes around the oil cooler 2, and thus, there is no need for troublesome piping work and piping retrieval space, and the electric vehicle drive device 1 that is easy to assemble to the electric vehicle can be obtained. In addition, since there is no portion where the piping protrudes around the oil cooler 2, the volumetric efficiency of the electric vehicle drive device 1 can be improved. In addition, when the first cooling water path 13a and the oil cooler water path 2a, the second cooling water path 13b and the oil cooler water path 2a, and the oil path 10 and the oil cooler oil path 2b are connected by a one-touch connector structure, when the oil cooler 2 is disassembled or replaced, the outflow of oil or cooling water can be suppressed, and garbage can be prevented from mixing into the oil cooler water path 2a or the oil cooler oil path 2b. In addition, the assemblability of the electric vehicle drive device 1 can be improved.

[0042] Implementation Method 2 An electric vehicle driving device 1 according to a second embodiment will be described. Fig.10 1 is a side view showing an oil cooler 2 and an inverter 7 as main parts of an electric vehicle driving device 1 according to a second embodiment, and is a view showing one side in the X direction. Fig.11 The diagram is a plan view showing the oil cooler 2 and the inverter 7 as the main parts of the electric vehicle driving device 1 , and is a diagram showing the electric vehicle driving device 1 without the cover 16 b . The electric vehicle driving device 1 of the second embodiment is configured such that the oil cooler 2 is provided on the cooling surface 12 a of the water cooling plate 12 .

[0043] like Fig.11 As shown, the inverter 7 includes: an electrical component 15; and a water cooling plate 12 having a first cooling water channel 13a and a second cooling water channel 13b formed inside. The water cooling plate 12 has a cooling surface 12a on which the electrical component 15 is mounted. The oil cooler 2 is disposed in contact with the cooling surface 12a and arranged in parallel with the electrical component 15.

[0044] The electrical component 15 is covered by the housing 16a and the cover 16b. In the present embodiment, the oil cooler 2 is arranged on one side of the housing 16a in the X direction. The structure of the oil cooler 2 is not limited to this, and for example, the oil cooler 2 may be arranged on one side of the housing 16a in the Y direction. The oil cooler 2 is fixed to the cooling surface 12a by welding or brazing, for example. The oil cooler 2 may also be fixed to the cooling surface 12a by bolts. In the case where the oil cooler 2 has an oil cooler oil circuit connection portion 8 or an oil cooler water circuit connection portion 9 on the cooling surface 12a side, in order to prevent the oil or cooling water from leaking between the oil cooler 2 and the cooling surface 12a, a sealing structure using an O-ring or a seal is provided in the connection portion connected to the oil circuit or the cooling water circuit.

[0045] In this way, by placing the oil cooler 2 in contact with the cooling surface 12a, and arranging the oil cooler 2 and the electrical component 15 in parallel, the piping between the inverter 7 and the oil cooler 2 is not required, and the connection between the inverter 7 and the oil cooler 2 can be simplified, so that the electric vehicle drive device 1 can be miniaturized and lightweight. In addition, since the inverter 7 and the oil cooler 2 of the electric vehicle drive device 1 are partially integrated, the installation workability of the electric vehicle drive device 1 to the electric vehicle can be improved. In addition, since the inverter 7 and the oil cooler 2 are partially integrated, the strength and vibration resistance of the inverter 7 and the oil cooler 2 can be improved.

[0046] In the present embodiment, the inverter 7 has: a power module 25 and a capacitor 26 arranged adjacent to the first cooling water channel 13a; and a cooling water inlet portion 17 for allowing cooling water to flow into the first cooling water channel 13a. The inverter 7 also has a cooling water outlet portion 18 for sending cooling water from the second cooling water channel 13b. In the present embodiment, the cooling water inlet portion 17 and the cooling water outlet portion 18 are arranged on the other side of the X direction of the water-cooled plate 12. The cooling water inlet portion 17 and the cooling water outlet portion 18 are, for example, joints. The power module 25 and the capacitor 26 are electrical components 15 mounted on the cooling surface 12a. The electrical components 15 mounted on the cooling surface 12a are not limited to the power module 25 and the capacitor 26, and other electrical components such as transformers may also be mounted on the cooling surface 12a.

[0047] The flow path of the cooling water for the cooling water circulation is described below. Fig.11In the figure, the flow direction of the cooling water is indicated by a solid arrow. The cooling water channel connecting portion 14a of the first cooling water channel 13a and the oil cooler water channel connecting portion 9 are connected through the cooling surface 12a, and the cooling water channel connecting portion 14b of the second cooling water channel 13b and the oil cooler water channel connecting portion 9 are connected through the cooling surface 12a. Low-temperature cooling water is supplied to the cooling water inlet portion 17 from an external water cooling system. The cooling water circulates in the order of the first cooling water channel 13a, the oil cooler water channel 2a, and the second cooling water channel 13b through the operation of a cooling water pump (not shown). The low-temperature cooling water first flows through the first cooling water channel 13a, and therefore, in order to enable more efficient cooling, it is desirable to form the first cooling water channel 13a to match the configuration of the electrical components 15 that are prone to heat.

[0048] In the present embodiment, the first cooling water channel 13a is configured so that the cooling water flowing in from the cooling water inlet 17 passes through the portion of the first cooling water channel 13a arranged adjacent to the power module 25 and the capacitor 26 in the order of the power module 25 and the capacitor 26. Among the electrical components 15, the component that is most likely to generate heat is the power module 25. The capacitor 26 is an electrical component 15 that generates heat and has a relatively low allowable temperature. By configuring in this way, low-temperature cooling water flows through the power module 25 and the capacitor 26 in sequence, so that the power module 25 and the capacitor 26 can be cooled more effectively.

[0049] The cooling water exchanges heat with the oil after cooling the power module 25 and the capacitor 26, and then flows through the second cooling water path 13b. Since the heated cooling water flows in the second cooling water path 13b, it is preferable to arrange electrical components with a higher allowable temperature and electrical components with a lower heat generation.

[0050] In this embodiment, a part of the oil passage 10 is provided inside the water cooling plate 12. Fig.10 and Fig.11 In the figure, the flow direction of oil is indicated by a dotted arrow. The oil cooler oil circuit connection portion 8 on the upstream side where the oil flows in is connected to the first plate oil circuit connection portion 27a provided on the cooling surface 12a of the water cooling plate 12 abutting against the oil cooler 2. The second plate oil circuit connection portion 28a provided on the side of the water cooling plate 12 abutting against the gear box 6 is connected to the oil circuit connection portion 11 of the gear box 6. A plate oil circuit 10a is formed in the portion of the water cooling plate 12 between the first plate oil circuit connection portion 27a and the second plate oil circuit connection portion 28a. The plate oil circuit 10a is an oil circuit formed in an L shape when viewed along the Y direction. The oil cooler oil circuit connection portion 8 and the oil circuit connection portion 11 are connected via the plate oil circuit 10a, and oil can flow through them.

[0051] The oil cooler oil path connection part 8 on the downstream side where the oil is supplied is connected to the first plate oil path connection part 27b provided on the cooling surface 12a of the water cooling plate 12 abutting against the oil cooler 2. An opening part 29 is provided in the second plate oil path connection part 28b provided on the surface on the other side of the Z direction of the water cooling plate 12 that discharges the oil to the outside. The plate oil path 10b is formed in the portion of the water cooling plate 12 between the first plate oil path connection part 27b and the second plate oil path connection part 28b. In the present embodiment, a joint 23 is provided in the opening part 29, and the joint 23 is connected to the oil path connection part provided on the motor 3.

[0052] In this embodiment, the oil cooler oil circuit connection part 8 is connected to the external oil circuit connection part via the plate oil circuits 10a and 10b, but the present invention is not limited thereto. The plate oil circuits 10a and 10b may not be provided to expose the oil cooler oil circuit connection part 8, and the oil cooler oil circuit connection part 8 may be directly connected to the external oil circuit connection part.

[0053] As described above, in the electric vehicle drive device 1 of the second embodiment, the inverter 7 has the electrical component 15, the water-cooling plate having the first cooling water channel 13a and the second cooling water channel 13b formed inside, the water-cooling plate 12 has the cooling surface 12a on which the electrical component 15 is mounted, and the oil cooler 2 is arranged in contact with the cooling surface 12a and arranged in parallel with the electrical component 15, so that the connection portion between the inverter 7 and the oil cooler 2 is not required, and the connection portion between the inverter 7 and the oil cooler 2 can be simplified, thereby making the electric vehicle drive device 1 miniaturized and lightweight. In addition, since the inverter 7 and the oil cooler 2 of the electric vehicle drive device 1 are partially integrated, the installation workability of the electric vehicle drive device 1 to the electric vehicle can be improved. In addition, since the inverter 7 and the oil cooler 2 are partially integrated, the strength and vibration resistance of the inverter 7 and the oil cooler 2 can be improved.

[0054] The inverter 7 has a power module 25 and a capacitor 26 arranged adjacent to the first cooling water channel 13a, and a cooling water inlet portion 17 for allowing cooling water to flow into the first cooling water channel 13a. When the first cooling water channel 13a is configured so that the cooling water flowing in from the cooling water inlet portion 17 passes through the portion of the first cooling water channel 13a arranged adjacent to the power module 25 and the capacitor 26 in the order of the power module 25 and the capacitor 26, among the electrical components 15, the component that is most prone to heat generation is the power module 25, and the capacitor 26 is also an electrical component 15 that is prone to heat generation. Therefore, low-temperature cooling water flows through the power module 25 and the capacitor 26 in sequence, thereby enabling the power module 25 and the capacitor 26 to be cooled more effectively.

[0055] Implementation 3 An electric vehicle driving device 1 according to a third embodiment will be described. Fig.121 is a side view showing an oil cooler 2 and an inverter 7 as main parts of an electric vehicle driving device 1 according to a third embodiment, and is a view showing one side in the X direction. Fig.13 The diagram is a plan view showing the oil cooler 2 and the inverter 7 as the main parts of the electric vehicle driving device 1 , and is shown without the cover 16 b. The electric vehicle driving device 1 of the third embodiment has a structure in which a cooling water pump 30 is provided on the cooling surface 12 a of the water cooling plate 12 .

[0056] The inverter 7 has a water-cooled plate 12 having a first cooling water channel 13a and a second cooling water channel 13b formed inside thereof, and a cooling water pump 30 for circulating cooling water in the water channel. The cooling water pump 30 is disposed in contact with the water-cooled plate 12. In the present embodiment, the cooling water pump 30 is disposed in contact with the cooling surface 12a of the water-cooled plate 12, and is disposed on one side of the housing 16a and the cover 16b covering the electrical component 15 in the X direction. The cooling water pump 30 is connected to one side of the cooling water channel connecting portion 14a of the first cooling water channel 13a. The inverter 7 supplies power to the cooling water pump 30 and performs drive control of the cooling water pump 30.

[0057] With this configuration, since the cooling water pump 30 and the inverter 7 are integrally structured, the wiring connecting the cooling water pump 30 and the inverter 7 can be shortened and the wiring connection can be simplified, thereby making the electric vehicle driving device 1 lighter and more compact.

[0058] In addition, in the present embodiment, the oil cooler 2 is disposed in contact with the cooling surface 12a, and the oil cooler 2 and the electrical component 15 are arranged in parallel. By forming an integrated structure (3 in 1) consisting of the inverter 7, the oil cooler 2 and the cooling water pump 30, the installation workability of the electric vehicle drive device 1 to the electric vehicle can be improved. In addition, since the inverter 7, the oil cooler 2 and the cooling water pump 30 are integrated, the strength and vibration resistance of the inverter 7, the oil cooler 2 and the cooling water pump 30 can be improved.

[0059] Implementation 4 An electric vehicle driving device 1 according to a fourth embodiment will be described. Fig.14 (a) is a cross-sectional view showing an oil cooler 2 which is a main part of the electric vehicle driving device 1 according to the fourth embodiment, and is Fig.14 A cross-sectional view obtained by cutting at the AA cross-sectional position of (b), Fig.14 (b) is a cross-sectional view of the oil cooler 2, and is Fig.14 A cross-sectional view obtained by cutting at the BB cross-sectional position of (a), Fig.15 (a) is a cross-sectional view showing an oil cooler 2 as a main part of another electric vehicle driving device 1 as a fourth embodiment, and is Fig.15The cross-sectional view obtained by cutting at the CC cross-sectional position of (b), Fig.15 (b) is a cross-sectional view of the oil cooler 2, and is Fig.15 A cross-sectional view obtained by cutting at the DD cross-sectional position of (a), Fig.16 (a) is a cross-sectional view showing an oil cooler 2 as a main part of another electric vehicle driving device 1 as a fourth embodiment, and is Fig.16 A cross-sectional view obtained by cutting at the EE cross-sectional position of (b), Fig.16 (b) is a cross-sectional view of the oil cooler 2, and is Fig.16 The electric vehicle driving device 1 of the fourth embodiment is a cross-sectional view obtained by cutting at the FF cross-sectional position of (a). The electric vehicle driving device 1 of the fourth embodiment has a structure in which a power conversion mechanism 31 for generating an oil flow by a water flow is provided in the oil cooler 2.

[0060] The oil cooler 2 has an oil cooler water passage 2a through which cooling water flows and an oil cooler oil passage 2b through which oil flows. The oil cooler water passage 2a and the oil cooler oil passage 2b are arranged in isolation without being connected. A power conversion mechanism 31 is provided in the oil cooler 2. The power conversion mechanism 31 uses the water flow generated by the cooling water flowing through the oil cooler water passage 2a as power and generates an oil flow in the oil cooler oil passage 2b.

[0061] use Fig.14 (a) and Fig.14 (b) of the present embodiment will be described with reference to the structure of the power conversion mechanism 31. The oil cooler 2 has an end plate 22 as a part of the oil cooler 2. The portion different from the end plate 22 of the oil cooler 2 is the main body 2c of the oil cooler 2. The end plate 22 has an oil cooler water passage 2a and an oil cooler oil passage 2b which are arranged in isolation from each other, and the power conversion mechanism 31 is provided in the end plate 22.

[0062] The power conversion mechanism 31 accommodates a gear 32 composed of a pair of magnets or a gear 32 in which one side is a magnet and the other side is composed of a magnetic material in each of the isolated oil cooler water circuit 2a and the oil cooler oil circuit 2b. The rotation of the gear 32 on the oil cooler water circuit 2a side is transmitted to the gear 32 on the oil cooler oil circuit 2b side by using magnetic force. The gear 32 on the oil cooler water circuit 2a side is set as gear 32a, and the gear 32 on the oil cooler oil circuit 2b side is set as gear 32b. The gear 32b is rotated by transmitting the rotation of the gear 32a to the gear 32b. In addition, the gear 32 is a component that can transmit the rotational force from the gear 32a to the gear 32b, and therefore, the whole or part of the gear 32 may also be a structure composed of a magnet or a magnetic material.

[0063] exist Fig.14 (a) and Fig.14In (b), the arrows drawn with thick lines indicate the flow direction of cooling water, and the arrows drawn with thin lines indicate the flow direction of oil. The arrows drawn with thick lines and the arrows drawn with thin lines have different shapes of their tip ends. The flow path of cooling water is described. Cooling water is supplied from the external water cooling system to the first cooling water path 13a, and the cooling water after passing through the first cooling water path 13a flows from the oil cooler water path connection portion 9 to the Fig.14 The oil cooler water path 2a1 in the end plate 22 shown on the left side of (a). After passing through the oil cooler water path 2a of the main body 2c of the oil cooler 2, the cooling water flows into the oil cooler water path 2a2 in the end plate 22 and passes through the Fig.14 The oil cooler water path 2a2 shown by the dotted line on the right side of (a) flows from the oil cooler water path connection portion 9 into the second cooling water path 13b. Fig.14 As shown in (b) of FIG. 2 , the gear 32a is provided on the end plate 22 so that a part of the gear 32a is exposed to the oil cooler water path 2a2. The gear 32a is rotated by the cooling water flowing through the oil cooler water path 2a2.

[0064] The oil flow path is described below. Fig.14 The oil flows into the oil cooler oil passage 2b of the main body 2c of the oil cooler 2 through the first oil cooler oil passage connection portion 8a shown in the lower right of (b). The oil flows into the oil cooler oil passage 2b in the main body 2c, then flows into the oil cooler oil passage 2b in the end plate 22, and is discharged from the second oil cooler oil passage connection portion 8b. Fig.14 As shown in (a) of FIG. 1 , the gear 32 b is provided on the end plate 22 so that a portion of the gear 32 b is exposed to the oil cooler oil passage 2 b .

[0065] By such a configuration, since the gear 32b is rotated by the rotation of the gear 32a, the oil in the oil cooler oil circuit 2b can be sucked from the main body 2c side of the oil cooler 2, and the oil can be discharged from the second oil cooler oil circuit connection part 8b. Through the flow of the oil, the low-temperature oil after heat exchange between the cooling water and the oil is discharged from the second oil cooler oil circuit connection part 8b, so the low-temperature oil can be supplied to the heating part of the electric vehicle drive device 1. In the heating part supplied with low-temperature oil, the heating part can be directly or indirectly cooled by the heat absorption of the oil. In addition, since the oil for cooling the heating part of the electric vehicle drive device 1 can be circulated by the flow of cooling water supplied from the external water cooling system, an oil pump for circulating the oil is not required, so that the electric vehicle drive device 1 can be made lightweight and miniaturized. In addition, since the oil flow is generated by the water flow, the power consumption can be reduced.

[0066] The end plate 22 for accommodating the gear 32 may be provided on any surface of the oil cooler 2. The rotating body provided in the power conversion mechanism 31 is not limited to the gear. For example, a structure in which a plurality of impellers are provided on the rotating shaft may be provided. By using the gear 32 as the rotating body provided in the power conversion mechanism 31, the power conversion mechanism 31 can be miniaturized and reduced in cost.

[0067] It is desirable that the end plate 22 is a material that allows magnetic force to pass easily, and the end plate 22 is made of, for example, a resin material. It is desirable that the magnet or magnetic material constituting the gear 32 does not rust in the oil cooler water path 2a2. Examples of magnets or magnetic materials that do not rust include ferrite, aluminum nickel cobalt, iron chromium cobalt, samarium cobalt, and samarium iron nitrogen. In addition, when using a material that rusts, such as iron, as a magnetic material, it is desirable to apply a coating such as a coating (organic coating) or an electroplating (inorganic coating) treatment.

[0068] In addition, in the present disclosure, since the power conversion mechanism 31 using magnetic force is used, unlike the power conversion mechanism that connects the gears through the shaft, the oil cooler water path 2a and the oil cooler oil path 2b are not connected but are configured in isolation, so there is no need to worry about the cooling water leaking from the oil cooler water path 2a to the oil cooler oil path 2b along the periphery of the shaft connecting the gears. Since the cooling water will not leak from the oil cooler water path 2a to the oil cooler oil path 2b, it is possible to prevent the electric vehicle drive device 1 from malfunctioning due to the cooling water intruding into the oil cooler oil path 2b. In addition, by forming the inverter, the oil cooler 2 with an oil pump function, and the cooling water pump into an integrated structure, it is possible to easily assemble these components into the electric vehicle drive device 1.

[0069] <Variation 1> use Fig.15 (a) and Fig.15 (b) illustrates the structure of variant example 1. Fig.15 The structure shown in (b) is Fig.14 The structure shown in (b) is different in the direction in which the gear 32 is set. Fig.14 In the structure shown in (b), the gear 32 is provided in parallel with the side surface 2c1 of the main body 2c of the oil cooler 2. Fig.15 In the structure shown in (b), the gear 32 is arranged perpendicularly to the side surface 2c1 of the main body 2c of the oil cooler 2. Fig.14 and Fig.15 In the structure of , the direction in which the oil is discharged from the second oil cooler oil passage connection portion 8b is different. Fig.14 In the structure shown in (b), the oil is discharged in a direction perpendicular to the side surface 2c1 of the main body 2c of the oil cooler 2. Fig.15 In the structure shown in (b), the oil is discharged in a direction parallel to the side surface 2c1 of the main body 2c of the oil cooler 2. Fig.15 Compared with the structure shown in (b), Fig.14 The structure shown in (b) can make the end plate 22 small.

[0070] <Variation 2> use Fig.16 (a) and Fig.16 (b) illustrates the structure of variant example 2. Fig.16 The structure shown in (a) is Fig.14 The structure shown in (a) is different in the position of the first oil cooler oil passage connection portion 8a. Fig.14 In the structure shown in (a), the first oil cooler oil passage connection portion 8a is provided in the main body portion 2c of the oil cooler 2. Fig.14 In the structure shown in (a), the first oil cooler oil path connection part 8a is provided on the end plate 22. By configuring in this way, both the first oil cooler oil path connection part 8a and the second oil cooler oil path connection part 8b can be arranged on the same side of the end plate 22. Since both the first oil cooler oil path connection part 8a and the second oil cooler oil path connection part 8b are arranged on the same side of the end plate 22, the productivity of the electric vehicle drive device 1 can be improved.

[0071] In addition, the present disclosure describes various exemplary embodiments and examples, but the features, embodiments, and functions described in one or more embodiments are not limited to application in specific embodiments, and can be applied to the embodiments alone or in various combinations. Therefore, numerous modifications not shown are contemplated within the technical scope disclosed in the present specification, including, for example, modification, addition, or omission of at least one component, and also including extraction of at least one component and combination with components of other embodiments.

[0072] Hereinafter, each embodiment of the present disclosure will be summarized and described as a supplement. (Note 1) An electric vehicle driving device, comprising: Electric motor; a gear box for accommodating a speed reduction mechanism connected to the motor and a differential mechanism connected to the speed reduction mechanism; an inverter electrically connected to the motor and converting electric power; and an oil cooler, wherein the oil cooler performs oil cooling on the electric motor, The inverter has a first cooling water path and a second cooling water path for cooling water to flow. The oil cooler has an oil cooler water path for cooling water to flow. The oil cooler is arranged in contact with the inverter. In the abutment portion, the first cooling water passage is connected to the oil cooler water passage, and the second cooling water passage is connected to the oil cooler water passage. A water passage is formed through which cooling water flows in the order of the first cooling water passage, the oil cooler water passage, and the second cooling water passage. (Note 2) The electric vehicle driving device according to Supplement 1, wherein: The oil cooler has an oil cooler oil passage for oil flow. The motor and the gearbox have an oil circuit connected to the oil circuit of the oil cooler. The oil cooler is disposed on the opposite side of the inverter to the electric motor or the gear box. In the contact portion, the oil passage is connected to an oil passage of the oil cooler, and the oil cooler is disposed so as to be sandwiched between the inverter and the electric motor or the gear box. (Note 3) The electric vehicle driving device according to Supplement 1, wherein: The inverter includes an electrical component and a water cooling plate having the first cooling water channel and the second cooling water channel formed therein. The water cooling plate has a cooling surface on which the electrical components are mounted. The oil cooler is provided in contact with the cooling surface and is arranged in parallel with the electrical component. (Note 4) An electric vehicle driving device according to any one of Supplementary Notes 1 to 3, wherein: The inverter includes: a power module and a capacitor arranged adjacent to the first cooling water channel; and a cooling water inlet for allowing cooling water to flow into the first cooling water channel. The first cooling water channel is provided so that the cooling water flowing in from the cooling water inlet portion passes through a portion of the first cooling water channel disposed adjacent to the power module and the capacitor in order of the power module and the capacitor. (Note 5) An electric vehicle driving device according to any one of Supplementary Notes 1 to 4, wherein: The inverter comprises: a water cooling plate, the first cooling water channel and the second cooling water channel being formed inside the water cooling plate; and a cooling water pump, the cooling water pump circulates cooling water in the water channels. The cooling water pump is disposed in contact with the water cooling plate. (Note 6) An electric vehicle driving device according to any one of Supplementary Notes 1 to 5, wherein: The oil cooler has an oil cooler oil passage for oil flow. The oil cooler water passage and the oil cooler oil passage are not connected but isolated. A power conversion mechanism is provided, which uses a water flow generated by cooling water flowing through the oil cooler water path as power to generate an oil flow in the oil cooler oil path. (Note 7) The electric vehicle driving device according to Supplementary Note 6, wherein: The power conversion mechanism contains a gear consisting of a pair of magnets or a gear in which one of the gears is a magnet and the other is made of a magnetic material in each of the isolated oil cooler water passage and the oil cooler oil passage. The rotation of the gear on the water channel side of the oil cooler is transmitted to the gear on the oil channel side of the oil cooler by using magnetic force. (Note 8) The electric vehicle driving device according to Supplement 2, wherein: The first cooling water passage and the oil cooler water passage, the second cooling water passage and the oil cooler water passage, and the oil passage and the oil cooler oil passage are connected by a one-touch connector structure.

Claims

1. An electric vehicle driving device, comprising: Electric motor; a gear box that accommodates a speed reduction mechanism connected to the motor and a differential mechanism connected to the speed reduction mechanism; an inverter, the inverter being electrically connected to the motor and converting electric power; as well as an oil cooler, wherein the oil cooler performs oil cooling on the electric motor, The inverter has a first cooling water path and a second cooling water path for cooling water to flow. The oil cooler has an oil cooler water path for cooling water to flow. The oil cooler is disposed in contact with the inverter. In the abutting portion, the first cooling water passage is connected to the oil cooler water passage, and the second cooling water passage is connected to the oil cooler water passage. A water channel is formed through which cooling water flows in the first cooling water channel, the oil cooler water channel, and the second cooling water channel in this order.

2. The electric vehicle driving device according to claim 1, characterized in that: The oil cooler has an oil cooler oil passage for oil flow. The motor and the gearbox have oil circuits connected to the oil circuit of the oil cooler, The oil cooler is disposed in contact with the motor or the gear box on the side opposite to the inverter. In the abutment portion, the oil passage is connected to the oil passage of the oil cooler. The oil cooler is disposed so as to be sandwiched between the inverter and the electric motor or the gear box.

3. The electric vehicle driving device according to claim 1, characterized in that: The inverter includes an electrical component and a water cooling plate having the first cooling water channel and the second cooling water channel formed therein. The water cooling plate has a cooling surface on which the electrical components are mounted. The oil cooler is provided in contact with the cooling surface and is arranged in parallel with the electrical component.

4. The electric vehicle driving device according to claim 1, characterized in that: The inverter includes: a power module and a capacitor arranged adjacent to the first cooling water channel; and a cooling water inlet portion for allowing cooling water to flow into the first cooling water channel. The first cooling water channel is provided so that the cooling water flowing in from the cooling water inlet portion passes through a portion of the first cooling water channel disposed adjacent to the power module and the capacitor in this order.

5. The electric vehicle driving device according to claim 1, characterized in that: The inverter includes: a water cooling plate having the first cooling water channel and the second cooling water channel formed inside the water cooling plate; and a cooling water pump that circulates cooling water in the water channels. The cooling water pump is disposed in contact with the water cooling plate.

6. The electric vehicle driving device according to claim 1, characterized in that: The oil cooler has an oil cooler oil passage for oil flow. The oil cooler water circuit and the oil cooler oil circuit are not connected but isolated. A power conversion mechanism is provided, which uses a water flow generated by cooling water flowing through the oil cooler water path as power and generates an oil flow in the oil cooler oil path.

7. The electric vehicle driving device according to claim 6, characterized in that: The power conversion mechanism contains a gear consisting of a pair of magnets or a gear in which one side is a magnet and the other side is made of a magnetic material in each of the isolated oil cooler water passage and the oil cooler oil passage. The rotation of the gear on the water channel side of the oil cooler is transmitted to the gear on the oil channel side of the oil cooler by using magnetic force.

8. The electric vehicle driving device according to claim 2, characterized in that: The first cooling water passage and the oil cooler water passage, the second cooling water passage and the oil cooler water passage, and the oil passage and the oil cooler oil passage are connected by a one-touch connector structure.

Images