Electric vehicle drive device

Abstract

An electric vehicle driving device includes: a motor; a gear box that accommodates the speed reduction mechanism and the differential mechanism connected to the speed reduction mechanism; one side of the tail end transmission gear shaft is connected with the differential mechanism; a support structure which supports the other side of the end transmission gear shaft and is fixed to the motor; and a radiator for cooling the motor, the motor and the end transmission gear shaft are oppositely arranged with an interval therebetween, one side of the motor and the end transmission gear shaft in the X direction is provided with a gear box, and the other side of the motor and the end transmission gear shaft in the X direction is provided with a support structure body. The radiator is provided on any one direction side or any two direction sides of the other side in the Y direction, one side in the Z direction, and the other side in the Z direction with respect to the end transfer gear shaft.

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 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 water pump.

[0004] By such a configuration, cooling water is supplied from the external water cooling system to the oil cooler, 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 heating 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 flowing out of the radiator is supplied to the oil cooler again. In the oil circulation of these oil cooling systems and the cooling water circulation of the external water cooling system, heat is transferred from the heating 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. In addition, in the external water cooling system, there are many cases in which a fan that blows air to the radiator in order to cool the cooling water more effectively and a liquid storage tank that ensures a sufficient amount of cooling water in order to suppress the mixing of air into the piping of the external water cooling system are provided.

[0005] In an electric vehicle, a battery is installed instead of the fuel tank of a conventional vehicle. In order to extend the cruising range of the electric vehicle, it is desired to improve the energy conversion efficiency including the lightening of the electric vehicle and the electric vehicle drive device, the increase of the battery installation capacity (the expansion of the battery installation space), and the reduction of the power consumption. In the structure of the above-mentioned patent document 1, the electric vehicle drive device can be properly cooled by providing an oil cooling system and an external water cooling system. However, since the electric vehicle drive device includes both the oil cooling system and the external water cooling system, the electric vehicle drive device is enlarged and the weight of the electric vehicle drive device is increased. Therefore, there is a technical problem that the electric vehicle and the electric vehicle drive device cannot be lightened, and the battery installation space cannot be expanded. In addition, since an external water cooling system is required, there is a technical problem that it is not easy to assemble the electric vehicle drive device into the electric vehicle.

[0006] In order to extend the cruising range of electric vehicles, structures that make electric vehicle drive devices lightweight and miniaturized are disclosed (for example, patent documents 2, 3, and 4). Patent document 2 discloses a structure that uses an oil pump that utilizes the rotational motion of a reducer to circulate the oil retained in the lower part of the housing that accommodates the reducer in the order of an oil pump, a motor, a cooler, an inverter (PDU), and a differential mechanism, and a structure that effectively cools the circulating oil by sending air to an oil cooler through a fan that utilizes the rotational motion of the motor. Patent document 3 discloses a structure of an electric vehicle drive device in which an impeller is provided on a drive shaft on which a tire is mounted. The structure is configured to air-cool the oil in the motor of the electric vehicle drive device arranged side by side with the impeller without increasing the cost. Patent document 4 discloses a structure of an electric vehicle drive device in which an opening is provided at the rear of the electric vehicle, and a passage is provided that can ventilate from the opening to the lower surface of the electric vehicle via the oil cooler. [Prior art literature] [Patent Document]

[0007] [Patent Document 1] Japanese Patent No. 7140727 [Patent Document 2] Japanese Patent No. 4625597 [Patent Document 3] Japanese Patent Application Publication No. 2015-186343. [Patent Document 4] Japanese Patent No. 6926984 Summary of the invention

[0008] In the structure of the above-mentioned patent document 2, since an external water cooling system is not required, the electric vehicle and the electric vehicle drive device can be made lightweight. In addition, since the rotational force of the electric motor is used directly or indirectly via a reducer as the driving force of the oil pump and the fan, the power consumption can be reduced. However, the maximum rotation number of the electric motor used in the electric vehicle is generally above 18000rpm, which is at high speed. Therefore, in the structure of patent document 2, fans with a maximum rotation number of less than 3000rpm, which are often used in people's livelihood and general industrial use, cannot be used. Since it is necessary to use a fan that has been strengthened to a high strength, the fan is expensive and large-scale, so there is a technical problem that the electric vehicle drive device cannot be lightweight and large-scale. In addition, since the fan and the cooler are arranged in series in the axial direction of the motor, the volumetric efficiency is poor, so there is a technical problem of large-scale electric vehicle drive device.

[0009] In the above-mentioned Patent Document 3, since an impeller is provided on the drive shaft, it is a structure that air-cools the oil in the electric motor that is provided in parallel with the impeller without increasing the cost. However, since the traveling wind passing under the electric motor is lifted by the impeller, it is difficult to change the flow of the traveling wind even if the impeller rotates in the released space, so there is a technical problem that the electric motor of the electric vehicle drive device cannot be effectively cooled. In addition, the drive shaft is generally installed in a manner extending in an inclined direction when viewed along the axial direction of the electric motor, which serves to absorb the forward and backward movement or up and down movement of the tire. Therefore, the drive shaft moves significantly, and the angle of the inclined direction changes, so the electric vehicle drive device and the impeller may come into contact, and the impeller may also be damaged.

[0010] In the above-mentioned patent document 4, since the oil cooler is ventilated and cooled without using a fan, the power consumption of the electric vehicle can be reduced. In addition, similar to the above-mentioned patent document 2, since an external water cooling system is not required, the electric vehicle and the electric vehicle drive device can be made lightweight. However, since the pressure difference between the opening at the rear of the electric vehicle and the lower surface of the electric vehicle is used as the ventilation driving force, the ventilation driving force will be greatly affected by the operating state (speed and winding driving, etc.) and the surrounding environment (weather, surrounding wind speed / wind direction, influence from surrounding vehicles (distance and relative speed), etc.). Therefore, the uncertainty of the air supply volume is high, and it is difficult to obtain a physically large ventilation driving force. In addition, sometimes the high-temperature exhaust air from the electric vehicle drive device itself or from the surrounding vehicles is attracted from the opening at the rear of the electric vehicle. Since a stable amount of air cannot be inhaled at a low temperature that can fully cool the electric vehicle drive device, there is a technical problem that the electric vehicle drive device cannot be effectively cooled. Furthermore, since air needs to be sent from the rear of the electric vehicle where the oil cooler is housed to the lower surface of the electric vehicle with low pressure loss, the ventilation path becomes enlarged, the volumetric efficiency is poor, and there is a technical problem of increasing the size of the electric vehicle drive device.

[0011] Therefore, an object of the present disclosure is to obtain an electric vehicle driving device that can be effectively cooled, is lightweight and compact, and can be easily assembled into an electric vehicle.

[0012] The electric vehicle drive device disclosed in the present invention includes: an electric motor having a rotating shaft; a gear box that accommodates a speed reduction mechanism connected to the rotating shaft and a differential mechanism connected to the speed reduction mechanism; a final drive gear shaft, one side of which is connected to the differential mechanism; a support structure that supports the other side of the final drive gear shaft and is fixed to the electric motor; and a radiator that cools the electric vehicle drive device. The electric motor and the final drive gear shaft are arranged opposite to each other with a gap therebetween, an extending direction of the final drive gear shaft is set as an X direction, a direction perpendicular to the X direction and in which the electric motor is provided relative to the final drive gear shaft is set as one side of the Y direction, and a direction perpendicular to the X direction and the Y direction is set as a Z direction, the gear box is provided on one side of the electric motor and the final drive gear shaft in the X direction, the support structure is provided on the other side of the electric motor and the final drive gear shaft in the X direction, and the radiator is provided on any one of the other side in the Y direction, one side in the Z direction, and the other side in the Z direction relative to the final drive gear shaft, or any two sides of the radiator.

[0013] According to the electric vehicle drive device disclosed in the present invention, the motor and the final transmission gear shaft are arranged relative to each other with a gap, a gear box is provided on one side of the motor and the final transmission gear shaft in the X direction, a support structure is provided on the other side of the motor and the final transmission gear shaft in the X direction, and a radiator is provided on any one of the other side in the Y direction, one side in the Z direction, and the other side in the Z direction or any two sides relative to the final transmission gear shaft. Therefore, a ventilation path and a radiator are provided around the final transmission gear shaft, and the heat generated inside the electric vehicle drive device can be dissipated without an external water cooling system, and the electric vehicle drive device can be effectively cooled. Since an external water cooling system is not required, the electric vehicle drive device can be made lightweight and miniaturized. Due to the lightweight and miniaturized electric vehicle drive device, the electric vehicle can be equipped with more batteries, thereby extending the cruising range of the electric vehicle. In addition, since an external water cooling system is not required, and the cooling mechanism formed by the ventilation path and the radiator is integrated with the electric vehicle drive device, the electric vehicle drive device can be easily assembled into the electric vehicle. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] 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 It is a diagram showing a coolant flow path of the electric vehicle driving device according to the first embodiment. Figure 5 This is a diagram showing another coolant flow path of the electric vehicle driving device according to the first embodiment. Figure 6 This is a diagram showing another coolant flow path of the electric vehicle driving device according to the first embodiment. Figure 7 This is a diagram showing another coolant flow path of the electric vehicle driving device according to the first embodiment. Figure 8 This is a diagram showing another coolant flow path of the electric vehicle driving device according to the first embodiment. Fig. 9 This is a cross-sectional view schematically showing the electric vehicle driving device according to the first embodiment. Fig.10 This is a front view schematically showing an electric vehicle driving device according to a second embodiment. Fig.11 This is a side view schematically showing the electric vehicle driving device according to the second embodiment. Fig.12 This is a cross-sectional view schematically showing an electric vehicle driving device according to a third embodiment. Fig.13 This is a side view schematically showing an electric vehicle driving device according to a fourth embodiment. Fig.14 This is a cross-sectional view schematically showing an electric vehicle driving device according to a fourth embodiment. Fig.15 This is a cross-sectional view schematically showing an electric vehicle driving device according to a fourth embodiment. Fig.16 This is a side view schematically showing an electric vehicle driving device according to a fourth embodiment. Fig.17 This is a cross-sectional view schematically showing an electric vehicle driving device according to a fifth embodiment. Fig.18 This is a cross-sectional view schematically showing an electric vehicle driving device according to a sixth embodiment. Fig.19 This is a cross-sectional view schematically showing an electric vehicle driving device according to a sixth embodiment. Explanation of symbols 1 electric vehicle drive device, 2 electric motor, 2a rotating shaft, 2b rotor, 2c housing, 2d stator, 3 speed reduction mechanism, 4 differential mechanism, 5 gear box, 6 final transmission gear shaft, 7 support structure, 8 inverter, 9 electric vehicle, 10 radiator, 11 coolant, 12 coolant pump, 13 reservoir, 14 coolant flow path, 14a, 14a1, 14a2 piping, 15 refrigerant-oil heat exchanger, 16 heat dissipation part, 17 heat pipe heat dissipation fin, 18 heat receiving part, 19 heat pipe, 20 additional heat pipe, 21 impeller, 21a airflow, 22 opening surface, 23 cover, 24 lid, 25, 25a heat dissipation fin, 26 gap, 27 housing, 28 fan, 29 air intake, 30 throat, 31 space, 32 air guide plate, 32a inclined part, 32b airflow, 33 wiring. DETAILED DESCRIPTION

[0015] 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.

[0016] 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 radiator 10 from the electric vehicle driving device 1. Figure 2(a) 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 9. Figure 2 (b) is a front view showing an outline of another electric vehicle driving device 1, and is a view viewed from the traveling direction of the electric vehicle 9. Figure 3 1 is a side view showing the outline of the electric vehicle driving device 1 as viewed from the other side in the X direction, and schematically shows an example of a state in which the electric vehicle driving device 1 is mounted on the front side of the electric vehicle 9. Figure 4 FIG. 1 is a diagram showing a coolant flow path 14 of the electric vehicle driving device 1 according to the first embodiment. Figures 5 to 8 FIG. 2 is a diagram showing another coolant flow path 14 of the electric vehicle driving device 1. Fig. 9 1 is a cross-sectional view showing an overview of the electric vehicle drive device 1, which is a view obtained by cutting the electric vehicle drive device 1 along the YZ plane. The electric vehicle drive device 1 installed in the electric vehicle 9 is a device that transmits the rotation of the rotating shaft 2a of the motor 2 to the final drive gear shaft 6 via the speed reduction mechanism 3 and the differential mechanism 4.

[0017] <Electric vehicle driving device 1> like Figure 2 As shown in (a), the electric vehicle driving device 1 includes a motor 2 having a rotating shaft, a gear box 5, a final drive gear shaft 6, a support structure 7 and a radiator 10. The electric vehicle driving device 1 also further includes an inverter 8 ( Figure 2 (not shown in the figure). The inverter 8 is fixed to the electric vehicle driving device 1, for example. The fixing position of the inverter 8 is not limited thereto, and the inverter 8 may be fixed to the electric vehicle 9 separately from the electric vehicle driving device 1.

[0018] like Figure 1 As shown in (b), the motor 2 includes a stator 2d having an iron core and a coil, a rotor 2b arranged inside the stator 2d, and a housing 2c accommodating the stator 2d and the rotor 2b. The rotating shaft 2a of the rotor 2b is supported by a bearing so as to be freely rotatable, and is arranged so as to be coaxially rotatable relative to the stator 2d. The housing 2c is made by casting or forging a metal such as aluminum, for example.

[0019] The gearbox 5 accommodates the speed reduction mechanism 3 connected to the rotating shaft 2a and the differential mechanism 4 connected to the speed reduction mechanism 3. The speed reduction mechanism 3 reduces the speed of the rotating shaft 2a of the motor 2 and outputs it. The differential mechanism 4 absorbs the speed difference between the left and right tires. The gearbox 5 is made by casting or forging a metal such as aluminum, for example.

[0020] One side of the final drive gear shaft 6 is connected to the differential mechanism 4. The support structure 7 supports the other side of the final drive gear shaft 6 so that it can rotate freely, and is fixed to the motor 2. Tires (not shown) are installed on both sides of the final drive gear shaft 6 via the drive shaft. The method of fixing the support structure 7 to the motor 2 is, for example, threaded fastening. The support structure 7 is made by casting or forging a metal such as aluminum. By using aluminum to make the housing 2c, the gear box 5 and the support structure 7, they can be made lightweight and low-cost, and complex shapes can also be easily made. In addition, by making these components from the same material, it can be a countermeasure against electrical corrosion. In addition, the material of these components is not limited to aluminum, and can also be a resin material.

[0021] The radiator 10 cools the motor 2. The parts of the motor 2 cooled by the radiator 10 are the bearings that support the coils of the stator 2d, the rotor 2b, the magnets, and the rotating shaft 2a so that they can rotate freely. The parts cooled by the radiator 10 are not limited to the motor 2, but may also be multiple parts of the heat generating parts of the electric vehicle drive device 1. The heat generating parts of the electric vehicle drive device 1 are parts that generate heat when the electric vehicle drive device 1 is driven. For example, in the reduction mechanism 3 and the differential mechanism 4, they are the gear meshing parts and the bearings that support these rotating shafts (gear shafts) so that they can rotate freely, and in the inverter 8, they are the electrical / electronic component groups (including power semiconductor elements, capacitors, reactors, control substrates including mounting components), busbars and other wiring, and the connection parts of the wiring. The details of the radiator 10 are described later.

[0022] <Structure of constituent members of electric vehicle driving device 1> The configuration of each component constituting the electric vehicle drive device 1 is described. The motor 2 and the final drive gear shaft 6 are arranged opposite to each other with a gap. Here, the directions are defined. The extending direction of the final drive gear shaft 6 is set as the X direction, the direction perpendicular to the X direction and in which the motor 2 is provided relative to the final drive gear shaft 6 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 direction opposite to the direction indicated by the arrow is set as the other side.

[0023] A gear box 5 is provided on one side of the motor 2 and the final transmission gear shaft 6 in the X direction, and a support structure 7 is provided on the other side of the motor 2 and the final transmission gear shaft 6 in the X direction. The heat sink 10 is provided on any one of the other side in the Y direction, one side in the Z direction, and the other side in the Z direction, or any two sides thereof, relative to the final transmission gear shaft 6. In this embodiment, as shown in FIG. Figure 3As shown, the heat sink 10 is arranged on one side of the Z direction relative to the final drive gear shaft 6. The structure of the heat sink 10 is not limited to this, and the heat sink 10 can also be arranged on the other side of the Y direction or the other side of the Z direction. The heat sink 10 is not limited to one, and two heat sinks can also be arranged. In the case of arranging two heat sinks 10, for example, Figure 2 As shown in (b), two heat sinks 10 are provided on both sides of one side in the Z direction and the other side in the Z direction relative to the final transmission gear shaft 6. In addition, the heat sink 10 may be a heat sink 10 extending to one side (or the other side) in the Z direction and the other side in the Y direction relative to the final transmission gear shaft 6 to form an L-shape.

[0024] By configuring the components constituting the electric vehicle drive device 1 in this way, the space around the final drive gear shaft 6 can be used as a ventilation path space that can be ventilated, and can be effectively used as a space for installing the radiator 10. Since the ventilation path and the radiator 10 are provided around the final drive gear shaft 6, an external water cooling system is not required, and the heat generated inside the electric vehicle drive device 1 can be dissipated, thereby effectively cooling the electric vehicle drive device 1. Since an external water cooling system is not required, the electric vehicle drive device 1 can be made lightweight and miniaturized. Due to the lightweight and miniaturized electric vehicle drive device 1, the electric vehicle 9 can be equipped with more batteries, thereby extending the cruising range of the electric vehicle 9. In addition, since an external water cooling system is not required, and the cooling mechanism formed by the ventilation path and the radiator 10 is integrated with the electric vehicle drive device 1, the electric vehicle drive device 1 can be easily assembled into the electric vehicle 9.

[0025] <Heat sink 10 and heat dissipation structure> First, the heat dissipation structure of the radiator 10 is described. In the present embodiment, the heat is dissipated by using a coolant circulating between the radiator 10 and the heat generating part. The coolant absorbs heat directly or indirectly from the heat generating part of the electric vehicle drive device 1. The coolant, which becomes high temperature due to the heat absorption, passes through the radiator 10. While passing through, the coolant dissipates heat to the air through the solid wall of the radiator 10 through radiation and convection heat transfer to the surroundings of the radiator 10. The low-temperature coolant 11 sent out from the radiator 10 is supplied to the heat generating part again. Through these series of actions, the heat generating part of the electric vehicle drive device 1 can be effectively cooled.

[0026] Next, the structure of the radiator 10 is described. The radiator 10 has a pipe that allows the coolant to move inside and a plurality of plate-shaped heat dissipating fins that are stacked and placed with arbitrary gaps along the extension direction of the pipe. Heat is transported to the entire pipe by the movement of the coolant. Heat is transferred from the pipe wall of the pipe to the heat dissipating fins by heat conduction, and heat is dissipated from the surface of the heat dissipating fins to the surroundings by radiation and convection heat transfer. The specific structure of the radiator 10 is, for example, a pipe structure in which two headers are connected by a plurality of pipes, a series of winding pipe structures, or a plurality of heat dissipating fins are stacked on a pipe structure in which a plurality of heat pipes are arranged in parallel, and the plurality of heat pipes can also be arranged with gaps between them.

[0027] <Coolant flow path 14> use Figures 4 to 8 , the structure of the coolant flow path 14 for circulating the coolant 11 will be described. In these figures, the coolant 11 circulates in the direction of the arrow. Figure 4 and Figure 5 The coolant flow path 14 shown will be described. Figure 4 and Figure 5 The radiator 10 shown is an air-cooled refrigerant cooler. The electric vehicle drive device 1 includes: a coolant pump 12 and a liquid storage tank 13 connected in series with the air-cooled refrigerant cooler through a pipe 14a for the flow of a coolant 11 as a refrigerant; and an inverter 8 electrically connected to the motor 2 and converting electric power. The coolant 11 is a refrigerant such as water, salt water (antifreeze) or a Freon-based refrigerant. The liquid storage tank 13 can be a storage tank (Japanese: アキュームレータ) or a liquid storage tank (Japanese: レシーバータンク). A coolant flow path 14 is formed for the coolant 11 contained in the liquid storage tank 13 to circulate in the order of the coolant pump 12, the air-cooled refrigerant cooler, and the liquid storage tank 13. The portion of the pipe 14 a of the coolant flow path 14 between the air-cooled refrigerant cooler and the tank 13 is provided so as to flow sequentially through the inverter 8 and the motor 2 in series or in parallel.

[0028] exist Figure 4 In the embodiment, the portion of the pipe 14a of the coolant flow path 14 between the air-cooled refrigerant cooler and the reservoir tank 13 is arranged so as to flow through the inverter 8 and the motor 2 in series in sequence. Figure 5 In the embodiment, the portion of the pipe 14a of the coolant flow path 14 between the air-cooled refrigerant cooler and the reservoir tank 13 is arranged to flow in parallel through the inverter 8 and the motor 2. An example of cooling the reduction mechanism 3 and the differential mechanism 4 will be described. The portion of the pipe 14a of the coolant flow path 14 is in contact with the gear box 5 that accommodates the reduction mechanism 3 and the differential mechanism 4, and indirectly cools the reduction mechanism 3 and the differential mechanism 4 via lubricating oil or a structure that forms the gear box 5.

[0029] By configuring in this way, since the inverter 8 is connected immediately after the air-cooled refrigerant cooler in the coolant flow path 14, the coolant 11 cooled in the air-cooled refrigerant cooler first passes through the inverter 8, thereby being able to cool the inverter 8 most effectively. The inverter 8, for example, has a water-cooled plate having a water path for the coolant 11 to pass therethrough. The water-cooled plate has a cooling surface on which an electrical / electronic equipment group is mounted. The electrical / electronic equipment group is effectively cooled by the coolant 11. When the coolant 11 is water, since the thermal properties of water are good and the heat exchange is one time, the inverter 8 can be cooled by water with the lowest temperature.

[0030] Next, Figure 6 The coolant flow path 14 shown will be described. Figure 6 The radiator 10 shown is an air-cooled refrigerant cooler. The electric vehicle drive device 1 includes: a coolant pump 12, a reservoir 13, and a refrigerant-oil heat exchanger 15 connected in series with the air-cooled refrigerant cooler through a pipe 14a for the coolant 11 as a refrigerant to flow; and an inverter 8 electrically connected to the motor 2 and converting electric power. The coolant 11 is a refrigerant such as water, salt water (antifreeze), or a Freon-based refrigerant. A coolant flow path 14 is formed for the coolant 11 contained in the reservoir 13 to circulate in the order of the coolant pump 12, the air-cooled refrigerant cooler, the refrigerant-oil heat exchanger 15, and the reservoir 13. The portion of the pipe 14a of the coolant flow path 14 between the air-cooled refrigerant cooler and the refrigerant-oil heat exchanger 15 is arranged so as to pass through the inverter 8.

[0031] The refrigerant-oil heat exchanger 15 has an oil circuit as a part of an oil cooling system (not shown) in addition to a water circuit as a part of the coolant flow path 14. In the refrigerant-oil heat exchanger 15, heat exchange is performed between the coolant 11 and the oil, and the oil is cooled by the coolant 11. The oil cooling system is, for example, a system that circulates oil that has been cooled in the refrigerant-oil heat exchanger 15 and has a low temperature. By circulating the low-temperature oil in the oil cooling system, the motor 2, the speed reduction mechanism 3, and the differential mechanism 4 can be cooled.

[0032] By configuring in this way, since the inverter 8 is connected after the air-cooled refrigerant cooler in the coolant flow path 14, and then the refrigerant-oil heat exchanger 15 is connected, the coolant 11 cooled in the air-cooled refrigerant cooler first cools the inverter 8 and then cools the oil in the refrigerant-oil heat exchanger 15, so that the inverter 8, the motor 2 and the gear box 5 can be evenly cooled. The cooled oil is in direct contact with the gears and bearings inside the gear box 5 and the coil ends and bearings in the motor, and can effectively cool them. Since the heat exchange from air to water and from water to oil occurs twice, the oil temperature will become high, but since the non-corrosive oil is lubricated, the gaps and protrusions of the gears, bearings, and coil ends can be directly cooled by the oil. Since the gaps and protrusions are directly cooled, the gears, bearings, and coil ends can be effectively cooled.

[0033] Next, Figure 7 and Figure 8 The coolant flow path 14 shown will be described. Figure 7 and Figure 8 The radiator 10 shown is an air-cooled oil cooler. The electric vehicle drive device 1 includes: a coolant pump 12 connected in series with the air-cooled oil cooler through a pipe 14a for the coolant 11 as a refrigerant to flow; and an inverter 8 electrically connected to the motor 2 and converting electric power. The coolant 11 is oil. The coolant pump 12 is provided in the gear box 5, and a coolant flow path 14 is formed for the coolant 11 retained at the bottom of the gear box 5 to circulate in the order of the coolant pump 12, the air-cooled oil cooler, and the gear box 5. The portion of the pipe 14a of the coolant flow path 14 between the air-cooled oil cooler and the gear box 5 is provided to flow sequentially through the inverter 8 and the motor 2 in series or in parallel through the inverter 8 and the motor 2.

[0034] exist Figure 7 In the embodiment, the portion of the pipe 14a of the coolant flow path 14 between the air-cooled oil cooler and the gear box 5 is arranged so as to flow through the inverter 8 and the motor 2 in series in sequence. Figure 8 In the embodiment, the portion of the pipe 14a of the coolant flow path 14 between the air-cooled oil cooler and the gear box 5 is arranged to flow in parallel through the inverter 8 and the motor 2. The oil is supplied from the portion of the pipe 14a of the coolant flow path 14 to the rotating shaft support structure and the gear contact portion of the speed reduction mechanism 3 and the differential mechanism 4 in the gear box 5, so that the speed reduction mechanism 3 and the differential mechanism 4 are cooled.

[0035] By configuring in this way, since the inverter 8 and the motor 2 are connected after the air-cooled oil cooler in the coolant flow path 14, and then the gear box 5 is connected, the coolant 11 cooled in the air-cooled oil cooler first directly cools the gears, bearings, coil ends, etc. inside the motor 2 together with the inverter 8, and then cools the inside of the gear box 5, so that the motor 2 and the gear box 5 can be cooled most effectively. The inverter 8, for example, has an oil cooling plate having an oil path for the coolant 11 to pass through. The oil cooling plate has a cooling surface on which an electrical / electronic equipment group is installed. The electrical / electronic equipment group is effectively cooled by the coolant 11. Although the thermal characteristics of oil are worse than those of water, since the heat exchange is one time, the temperature of the oil is the lowest, and the motor 2 can be effectively cooled.

[0036] In addition, as needed, a filter for recovering garbage inside the coolant flow path 14, a diverter for adjusting and switching the distribution amount of the coolant 11, and an additional flow path for lubricating the coolant to other heat-generating parts can be set in the middle of the coolant flow path 14.

[0037] <Configuration Example of Electric Vehicle Driving Device 1> use Fig. 9 , a structural example of an electric vehicle drive device 1 is described. The electric vehicle drive device 1 includes: a plurality of heat pipes 19, each of which has a heat dissipation portion 16 on one side and a heat receiving portion 18 on the other side; and an inverter 8, which is electrically connected to the motor 2 and converts electric power. The radiator 10 is a heat dissipation portion 16 having a plurality of heat pipe heat dissipation fins 17. The heat receiving portion 18 is thermally connected to one or both of the motor 2 and the inverter 8. In the present embodiment, the heat receiving portion 18 is thermally connected to both the motor 2 and the inverter 8. The radiator 10 is arranged on one side of the Z direction relative to the final drive gear shaft 6. Each of the plurality of heat pipes 19 is arranged, for example, with a gap and arranged in the X direction. The X direction is a direction perpendicular to the paper surface.

[0038] By configuring in this way, since the radiator 10 is part of the plurality of heat pipes 19, an external water cooling system is not required, and the heat generated inside the electric vehicle drive device 1 can be dissipated, thereby effectively cooling the electric vehicle drive device 1. Since an external water cooling system is not required, the electric vehicle drive device 1 can be made lightweight and miniaturized. Due to the lightweight and miniaturized electric vehicle drive device 1, the electric vehicle 9 can be equipped with more batteries, thereby extending the cruising range of the electric vehicle 9. In addition, since an external water cooling system is not required, and the cooling mechanism formed by the ventilation path and the radiator 10 and the inverter 8 are integrated with the electric vehicle drive device 1, the electric vehicle drive device 1 can be easily assembled into the electric vehicle 9.

[0039] The inverter 8 is thermally connected to one side of the heat receiving portion 18 of the heat pipe 19 in the Z direction, and the motor 2 is thermally connected to the other side of the heat receiving portion 18 of the heat pipe 19 in the Z direction. The heat receiving portion 18 of the heat pipe 19 is sandwiched between the motor 2 and the inverter 8. The arrangement of the inverter 8 and the heat pipe 19 is not limited thereto, and the heat pipe 19 may be disposed on the other side of the Z direction relative to the final drive gear shaft 6 and the motor 2. In the case where the heat pipe 19 is disposed on the other side of the Z direction relative to the final drive gear shaft 6 and the motor 2, the inverter 8 is, for example, thermally connected to the other side of the heat receiving portion 18 of the heat pipe 19 in the Z direction, and the motor 2 is thermally connected to one side of the heat receiving portion 18 of the heat pipe 19 in the Z direction.

[0040] exist Fig. 9 In the structure shown, a plurality of grooves respectively abutting against the outer peripheral surface of the heat pipe 19 may be provided on the other side of the inverter 8 in the Z direction and on the one side of the motor 2 in the Z direction so as to abut against the heat pipe 19 without a gap. In addition, instead of providing grooves on the inverter 8 and the motor 2, heat receiving plates as different components may be provided between the inverter 8 and the heat pipe 19 and between the motor 2 and the heat pipe 19, and the outer peripheral surface of the heat pipe 19 may abut against each of the plurality of grooves provided on the heat receiving plate. In addition, the heat pipe 19 may be inserted into each of the through holes of the heat receiving plate provided with the through holes, and the heat receiving plate provided with the heat pipe 19 may be sandwiched between the inverter 8 and the motor 2.

[0041] In addition to the heat pipe 19, an additional heat pipe 20 may be provided. The additional heat pipe 20 is provided in contact with the housing 2c that accommodates the motor 2. By configuring in this way, the motor 2 can be evenly heated over the entire circumference, and the heat of the motor 2 can be effectively transferred to the heat receiving portion 18 of the heat pipe 19 that is in contact with the motor 2. Since the heat of the motor 2 is effectively transferred, the motor 2 can be further cooled.

[0042] like Fig. 9 As shown, when the central portion of the additional heat pipe 20 is arranged on the other side of the motor 2 in the Z direction, since the additional heat pipe 20 generates a flow of coolant on both sides in the Y direction, heat can be transported on both sides in the Y direction. Since heat can be transported on both sides in the Y direction, the additional heat pipe 20 can transport heat more efficiently. In addition, when the additional heat pipe 20 and the heat receiving portion 18 of the heat pipe 19 provided in the housing 2c are alternately arranged in the X direction, the height of the heat pipe 19 and the additional heat pipe 20 provided in the X direction in the Z direction can be reduced, so that the electric vehicle drive device 1 can be miniaturized.

[0043] As described above, in the electric vehicle drive device 1 of the first embodiment, the motor 2 and the final transmission gear shaft 6 are arranged opposite to each other with a gap, the gear box 5 is provided on one side of the motor 2 and the final transmission gear shaft 6 in the X direction, the support structure 7 is provided on the other side of the motor 2 and the final transmission gear shaft 6 in the X direction, and the radiator 10 is provided on any one direction side or any two directions side of the other side of the Y direction, one side of the Z direction, and the other side of the Z direction relative to the final transmission gear shaft 6. Therefore, the ventilation path and the radiator 10 are provided around the final transmission gear shaft 6, and the heat generated inside the electric vehicle drive device 1 can be dissipated without an external water cooling system, so that the electric vehicle drive device 1 can be effectively cooled. Since the external water cooling system is not required, the electric vehicle drive device 1 can be made lightweight and small. Due to the lightweight and small size of the electric vehicle drive device 1, the electric vehicle 9 can be equipped with more batteries, so that the cruising distance of the electric vehicle 9 can be extended. Furthermore, since an external water cooling system is not required and the cooling mechanism formed by the ventilation path and the radiator 10 is integrated with the electric vehicle driving device 1 , the electric vehicle driving device 1 can be easily assembled into the electric vehicle 9 .

[0044] The radiator 10 is an air-cooled refrigerant cooler, and the electric vehicle drive device 1 includes: a coolant pump 12 and a liquid storage tank 13 connected in series with the air-cooled refrigerant cooler through a pipe 14a for the flow of coolant 11 as a refrigerant; and an inverter 8, forming a coolant flow path 14 for the coolant 11 contained in the liquid storage tank 13 to circulate in the order of the coolant pump 12, the air-cooled refrigerant cooler, and the liquid storage tank 13. The portion of the pipe 14a of the coolant flow path 14 between the air-cooled refrigerant cooler and the liquid storage tank 13 is arranged to flow through the inverter 8 and the motor 2 in series or in parallel in sequence. In the case where the inverter 8 is connected immediately after the air-cooled refrigerant cooler in the coolant flow path 14, the coolant 11 cooled in the air-cooled refrigerant cooler first passes through the inverter 8, thereby enabling the inverter 8 to be cooled most effectively. Furthermore, when the coolant 11 is water, since water has good thermal properties and heat exchange is performed once, the inverter 8 can be cooled by the water having the lowest temperature.

[0045] The radiator 10 is an air-cooled refrigerant cooler, and the electric vehicle driving device 1 includes a coolant pump 12, a liquid storage tank 13, and a refrigerant-oil heat exchanger 15 connected in series with the air-cooled refrigerant cooler through a pipe 14a for the coolant 11 as a refrigerant to flow; and an inverter 8, which forms a coolant flow path 14 for the coolant 11 contained in the liquid storage tank 13 to circulate in the order of the coolant pump 12, the air-cooled refrigerant cooler, the refrigerant-oil heat exchanger 15, and the liquid storage tank 13. When the portion of the pipe 14a of the coolant flow path 14 between the air-cooled refrigerant cooler and the refrigerant-oil heat exchanger 15 is arranged so as to pass through the inverter, the inverter 8 is connected after the air-cooled refrigerant cooler in the coolant flow path 14, and then the refrigerant-oil heat exchanger 15 is connected. Therefore, the coolant 11 cooled in the air-cooled refrigerant cooler first cools the inverter 8, and then cools the oil in the refrigerant-oil heat exchanger 15, so that the inverter 8, the motor 2 and the gear box 5 can be cooled evenly. In addition, the cooled oil directly contacts the gears and bearings inside the gear box 5 and the coil ends and bearings in the motor, and can effectively cool them.

[0046] The radiator 10 is an air-cooled refrigerant cooler, and the electric vehicle drive device 1 includes: a coolant pump 12 connected in series with the air-cooled refrigerant cooler through a pipe 14a through which a coolant 11 as a refrigerant flows; and an inverter 8, the coolant pump 12 is provided at the gear box 5, and a coolant flow path 14 is formed for the coolant 11 retained at the bottom of the gear box 5 to circulate in the order of the coolant pump 12, the air-cooled oil cooler, and the gear box 5, and a portion of the pipe 14a of the coolant flow path 14 between the air-cooled oil cooler and the gear box 5 is provided. When the inverter 8 and the motor 2 are sequentially arranged in series or in parallel, the inverter 8 and the motor 2 are connected to the inverter 8 and the motor 2 in the cooling liquid flow path 14 after the air-cooled oil cooler, and then the gear box 5 is connected. Therefore, the cooling liquid 11 cooled in the air-cooled oil cooler first directly cools the gears, bearings, coil ends, etc. in the motor 2 together with the inverter 8, and then cools the inside of the gear box 5, so that the motor 2 and the gear box 5 can be cooled most effectively. In addition, although the thermal characteristics of oil are worse than those of water, since the heat exchange is one time, the temperature of the oil is the lowest, and the motor 2 can be cooled effectively.

[0047] The electric vehicle driving device 1 includes: a plurality of heat pipes 19, the plurality of heat pipes 19 having a heat dissipation portion 16 on one side and a heat receiving portion 18 on the other side; and an inverter 8, a radiator 10 is a heat dissipation portion 16 having a plurality of heat pipe heat dissipation fins 17, and the heat receiving portion 18 is a part of the plurality of heat pipes 19 when it is thermally connected to one or both of the motor 2 and the inverter 8, so that the heat generated inside the electric vehicle driving device 1 can be dissipated without an external water cooling system, thereby effectively cooling the electric vehicle driving device 1. Since the external water cooling system is not required, the electric vehicle driving device 1 can be made lightweight and small. Due to the lightweight and small size of the electric vehicle driving device 1, the electric vehicle 9 can be equipped with more batteries, thereby extending the cruising range of the electric vehicle 9. In addition, since the external water cooling system is not required, and the cooling mechanism formed by the ventilation path and the radiator 10 and the inverter 8 are integrated with the electric vehicle driving device 1, the electric vehicle driving device 1 can be easily assembled into the electric vehicle 9.

[0048] Implementation method 2. An electric vehicle driving device 1 according to a second embodiment will be described. Fig.10 1 is a front view showing an outline of an electric vehicle driving device 1 according to Embodiment 2, and is a view viewed from the traveling direction of the electric vehicle. Fig.11 It is a side view schematically showing the electric vehicle driving device 1 and is a view showing the other side in the X direction without the support structure 7 from the electric vehicle driving device 1. The electric vehicle driving device 1 of the second embodiment has a structure in which the final gear shaft 6 has the impeller 21 .

[0049] The structure of the final gear shaft 6 provided with the impeller 21 in this embodiment will be described. The final gear shaft 6 has the impeller 21 that rotates integrally with the final gear shaft 6. The driving shaft of the impeller 21 is the final gear shaft 6. Fig.10 As shown in the figure, similarly to the first embodiment, the final gear shaft 6 is extended in the X direction between the gear box 5 and the support structure 7. Each end of the final gear shaft 6 is rotatably mounted on the gear box 5 or the support structure 7. The motor 2 and the radiator 10 are fixed to the gear box 5 and the support structure 7, respectively. Fig.11 As shown, the motor 2 is disposed on one side of the final transmission gear shaft 6 in the Y direction, and the heat sink 10 is disposed on one side of the final transmission gear shaft 6 in the Z direction. The final transmission gear shaft 6 is disposed at an arbitrary interval from each of the heat sink 10 and the motor 2, and the final transmission gear shaft 6 has a space around it. An impeller 21 of a size that can be accommodated in the space is fixed to the final transmission gear shaft 6.

[0050] In the present embodiment, four plate-shaped impellers 21 are in contact with and fixed to the final transmission gear shaft 6. The number, shape, and arrangement of the impellers 21 are not limited thereto. For example, instead of directly contacting the impellers 21 with the final transmission gear shaft 6, the impellers 21 may be surrounded by an outer frame portion fixed with the impellers 21 and contact the final transmission gear shaft 6, and the impellers 21 and the outer frame portion may rotate integrally with the final transmission gear shaft 6. Since the final transmission gear shaft 6 has the impellers 21 that rotate integrally with the final transmission gear shaft 6, as shown in FIG. Fig.10 As shown, a fan 28 is formed.

[0051] Since the ends of the final transmission gear shaft 6 are supported by the gear box 5 or the support structure 7, respectively, and the final transmission gear shaft 6 is arranged in parallel with the motor 2, the distance between the final transmission gear shaft 6 and the motor 2 is always constant. Therefore, when the impeller 21 is arranged on the side of the motor 2 during rotation, the distance between the end of the impeller 21 on the side opposite to the one side mounted on the final transmission gear shaft 6 and the motor 2 in the Y direction is always constant, so that the impeller 21 and the motor 2 do not interfere with each other. Similarly, the distance between the end of the impeller 21 on the side opposite to the one side mounted on the final transmission gear shaft 6 and the radiator 10 in the Z direction is always constant, and the impeller 21 and the radiator 10 do not interfere with each other.

[0052] In the present embodiment, the rotation of the motor 2 is transmitted to the final transmission gear shaft 6 via the reduction mechanism 3 and the differential mechanism 4, and the impeller 21 fixed to the final transmission gear shaft 6 rotates integrally with the final transmission gear shaft 6. The rotation of the impeller 21 generates an airflow 21a around the final transmission gear shaft 6. In the figure, the flow direction of the airflow 21a is indicated by an arrow. The airflow 21a passes through the radiator 10 arranged adjacent to the impeller 21. In addition, the airflow 21a flows along the outer surface of the motor 2 arranged adjacent to the impeller 21. Since the radiator 10 and the motor 2 are forced to be air-cooled by the airflow 21a, the electric vehicle drive device 1 can be cooled more effectively than in the first embodiment.

[0053] The maximum rotation speed of the motor 2 used in the electric vehicle is generally above 18000 rpm, and the motor 2 operates at a high speed. In the case where the impeller 21 is provided on the rotating shaft 2a of the motor 2, since a fan reinforced with high strength is required, the fan is expensive and large-sized, and there is a technical problem that the electric vehicle drive device 1 cannot be lightweight and large-sized. In addition, since the impeller 21 rotates at a high speed, there is a problem that the noise caused by the rotation of the impeller 21 increases significantly. As the speed ratio of the motor 2 and the final transmission gear shaft 6, the reduction ratio of the reduction mechanism 3 and the differential mechanism 4 is about 10, so the rotation speed of the final transmission gear shaft 6 is about 2000 rpm. Since the final transmission gear shaft 6 has the impeller 21, it is not necessary to particularly strengthen the impeller 21, and the noise will not increase significantly.

[0054] In addition, since the heat is dissipated from the radiator 10 and the motor 2 by the airflow 21a artificially generated by the impeller 21, the influence of the operating state (speed, winding driving, etc.) and the surrounding environment (weather, surrounding wind speed / direction, influence of surrounding vehicles (distance and relative speed), etc.) is reduced. Since the influence of the operating state and the surrounding environment is reduced, stable and low-temperature air can be fully supplied to the radiator 10 and the motor 2.

[0055] As described above, in the electric vehicle drive device 1 of embodiment 2, since the final drive gear shaft 6 has the impeller 21 that rotates integrally with the final drive gear shaft 6, the volume of the electric vehicle drive device 1 will not be increased, the space around the final drive gear shaft 6 can be effectively utilized, and stable and low-temperature air can be fully supplied to the radiator 10 with low noise, thereby enabling the electric vehicle drive device 1 to be cooled more effectively.

[0056] Implementation method 3. An electric vehicle driving device 1 according to a third embodiment will be described. Fig.12 This is a cross-sectional view schematically showing the electric vehicle driving device 1 according to the third embodiment, and is a view cut along the YZ plane. The electric vehicle driving device 1 according to the third embodiment has a structure in which the inverter 8 is provided around the final gear shaft 6 .

[0057] The structure in which the inverter 8 is provided around the final gear shaft 6 in this embodiment will be described. The electric vehicle driving device 1 includes the inverter 8 which is electrically connected to the motor 2 and converts electric power. The radiator 10 is provided on the other side of the Y direction, one side of the Z direction, and the other side of the Z direction with respect to the final gear shaft 6, and the inverter 8 is provided on the other side of the Y direction, one side of the Z direction, and the other side of the Z direction with respect to the final gear shaft 6, and is the side on which the radiator 10 is not provided. In this embodiment, the inverter 8 is provided on the other side of the Z direction with respect to the final gear shaft 6, and the radiator 10 is provided on the one side of the Z direction with respect to the final gear shaft 6. The structure of the inverter 8 and the radiator 10 is not limited to this, and the inverter 8 may be provided on one side of the Z direction with respect to the final gear shaft 6, and the radiator 10 may be provided on the other side of the Z direction with respect to the final gear shaft 6. In addition, either the inverter 8 or the radiator 10 may be provided on the other side of the Y direction with respect to the final gear shaft 6.

[0058] By configuring in this way, the flow of air can be cut off on the side where the inverter 8 is provided, and the intake of air can be suppressed on the side where the radiator 10 is provided. Therefore, the inverter 8 and the radiator 10 can be used as part of the ventilation path for regulating the flow of air, and the remaining side where the inverter 8 and the radiator 10 are not provided can be used as the opening surface 22 for supplying air to the impeller 21. The opening surface 22 is an intake surface for inhaling low-temperature air around the electric vehicle drive device 1. The ventilation path is formed by the inverter 8, the motor 2, the gear box 5 and the supporting structure 7. The air flowing in from the opening surface 22 passes through the impeller 21 and then passes through the radiator 10, so that a unidirectional airflow 21a can be formed. Since the unidirectional airflow 21a is formed, low-temperature air is stably supplied to the radiator 10, so that the electric vehicle drive device 1 can be cooled more effectively. In the structure shown in Embodiment 2, since the remaining two sides of the radiator 10 are not provided to help both intake and exhaust, and a unidirectional airflow is not formed, the air around the final drive gear shaft 6 is disturbed, and the electric vehicle drive device 1 cannot be cooled sufficiently and effectively.

[0059] In the present embodiment, the electric vehicle drive device 1 includes a cover 23, and the cover 23 has a ventilation opening for air flow in the opening surface 22 on the side where the radiator 10 and the inverter 8 are not provided, which is the other side of the Y direction, one side of the Z direction, and the other side relative to the final drive gear shaft 6. The cover 23 prevents the intrusion of flying stones that may cause damage to the impeller 21 and the radiator 10, and suppresses the clogging of the radiator 10 by garbage. The cover 23 is, for example, a filter, a metal mesh, a punched metal plate, or a louvered plate. By providing the cover 23, it is possible to prevent the impeller 21 and the radiator 10 from being damaged by the intrusion of flying stones, and it is possible to ensure that air is sucked into the stable electric vehicle drive device 1, thereby maintaining a good cooling state of the electric vehicle drive device 1.

[0060] In the present embodiment, the Z direction is a vertical direction, one side of the Z direction is set as the vertical upper side, and the other side of the Z direction is set as the vertical lower side. The inverter 8 is set on the other side of the Z direction relative to the final gear shaft 6, and the inverter 8 has a cover 24 that can be detached from the other side of the Z direction. The other side of the inverter 8 in the Z direction when the cover 24 is removed becomes a maintenance work surface of the inverter 8. In the case where the inverter 8 is set on one side of the Z direction relative to the final gear shaft 6 or one side of the Z direction of the motor 2, when the inverter 8 fails, it is necessary to get off the electric vehicle drive device 1 itself from the electric vehicle 9 to maintain the inverter 8. By setting the inverter 8 on the other side of the Z direction relative to the final gear shaft 6, the inverter 8 has a cover 24 that can be detached from the other side of the Z direction, and the cover 24 of the inverter 8 can be removed from the vertical lower side of the electric vehicle 9 without getting off the electric vehicle drive device 1 itself, and the maintenance work of the inverter 8 can be easily performed.

[0061] In this embodiment, one or both of the motor 2 and the inverter 8 has a plurality of heat dissipation fins 25 on the side of the final gear shaft 6. Fig.12 In the structure shown, both the motor 2 and the inverter 8 have a plurality of heat dissipation fins 25. The plurality of heat dissipation fins 25 are arranged in the X direction in the ventilation path formed by the inverter 8, the motor 2, the gear box 5, and the support structure 7. With such a structure, in addition to the heat dissipation of the radiator 10, the electric vehicle drive device 1 can also dissipate heat from the heat dissipation fins 25 by the low-temperature air flowing in from the opening surface 22 and passing through the ventilation path. Since the electric vehicle drive device 1 also dissipates heat from the heat dissipation fins 25, the electric vehicle drive device 1 can be cooled more effectively.

[0062] The location where the heat dissipation fins 25 are provided is not limited thereto. In the present embodiment, the inverter 8 has a plurality of heat dissipation fins 25a on the cover 24, which is a portion on the side opposite to the side of the final drive gear shaft 6. The plurality of heat dissipation fins 25a are formed in a plate shape, for example, and are arranged in an array along the X direction. With such a configuration, the inverter 8 is cooled by the traveling wind passing through the other side of the inverter 8 in the Z direction, and therefore, the electric vehicle drive device 1 can be cooled more effectively.

[0063] In this embodiment, the inverter 8 is disposed on one side of the Z direction or the other side of the Z direction relative to the final drive gear shaft 6, and the motor 2 and the inverter 8 are disposed with a gap therebetween. Fig.12 In the structure shown, the inverter 8 is provided on the other side of the final drive gear shaft 6 in the Z direction, and a gap 26 is provided between the motor 2 and the inverter 8. By configuring in this way, the air flowing into the ventilation path can flow out from the gap 26, so that the air passes through the portion of the heat dissipation fin 25 that is adjacent to the portion of the gap 26 and abuts against the motor 2 or the inverter 8, thereby being able to cool the electric vehicle drive device 1 more effectively.

[0064] As described above, in the electric vehicle driving device 1 of the third embodiment, the radiator 10 is provided on the other side in the Y direction, one side in the Z direction, and the other side in the Z direction with respect to the final drive gear shaft 6, and the inverter 8 is provided on the other side in the Y direction, one side in the Z direction, and the other side in the Z direction with respect to the final drive gear shaft 6, and on the side where the radiator 10 is not provided, so that the inverter 8, the motor 2, the gear box 5, and the support structure 7 form a ventilation path, and the air flowing in from the ventilation surface 22 passes through the impeller 21 and then passes through the radiator 10, thereby forming a unidirectional airflow 21a. Since the unidirectional airflow 21a is formed, low-temperature air is stably supplied to the radiator 10, so that the electric vehicle driving device 1 can be cooled more effectively.

[0065] In the case where the inverter 8 is provided on the other side in the Z direction relative to the final drive gear shaft 6 and the inverter 8 has a cover 24 that can be attached and detached on the other side in the Z direction, the cover 24 of the inverter 8 can be removed from the vertically lower side of the electric vehicle 9 without getting off the electric vehicle drive device 1 itself from the electric vehicle 9, and maintenance work on the inverter 8 can be easily performed. In addition, in the case where the electric vehicle drive device 1 includes a cover 23, the cover 23 has a ventilation opening for air to flow in the opening surface 22 on the side that is the other side in the Y direction, one side in the Z direction, and the other side in the Z direction relative to the final drive gear shaft 6 and on which the radiator 10 and the inverter 8 are not provided, damage to the impeller 21 and the radiator 10 due to the intrusion of flying stones can be prevented, and air intake to the stable electric vehicle drive device 1 can be ensured, so that a good cooling state of the electric vehicle drive device 1 can be maintained.

[0066] In the case where one or both of the motor 2 and the inverter 8 have a plurality of fins 25 at the portion on the side of the final gear shaft 6, in addition to the heat dissipation in the radiator 10, the electric vehicle drive device 1 can also dissipate heat from the heat dissipation fins 25 by the low-temperature air flowing in from the opening surface 22 and passing through the ventilation path, thereby more effectively cooling the electric vehicle drive device 1. In addition, in the case where the inverter 8 is provided on one side or the other side in the Z direction relative to the final gear shaft 6, and the motor 2 and the inverter 8 are provided with a gap 26 therebetween, since the air flowing into the ventilation path can be made to flow out from the gap 26, the air passes through the portion of the fin 25 that is adjacent to the portion of the gap 26 and abuts against the motor 2 or the inverter 8, thereby more effectively cooling the electric vehicle drive device 1. In addition, when the inverter 8 has a plurality of heat dissipation fins 25a on the cover 24 on the side opposite to the final drive gear shaft 6, the inverter 8 is cooled by the traveling wind passing through the other side of the inverter 8 in the Z direction, thereby being able to cool the electric vehicle drive device 1 more effectively.

[0067] Implementation method 4. An electric vehicle driving device 1 according to a fourth embodiment will be described. Fig.13 1 is a side view showing an outline of the electric vehicle driving device 1 according to the fourth embodiment, and is a view viewed from the other side in the X direction. Fig.14 1 is a cross-sectional view showing an outline of the electric vehicle driving device 1, and is a view obtained by cutting along the YZ plane. Fig.15 1 is a cross-sectional view showing an outline of the electric vehicle driving device 1, and is a view obtained by cutting along the YZ plane. Fig.16It is a side view showing the outline of the electric vehicle driving device 1 and is a view seen from the other side in the X direction. The electric vehicle driving device 1 of the fourth embodiment has a structure in which a flow path of air is formed around the impeller 21 by the casing 27 .

[0068] The electric vehicle drive device 1 includes a housing 27, which covers the periphery of the impeller 21 and forms a flow path for air flowing in and out of the impeller 21. As described above, the inverter 8, the motor 2, the gear box 5, and the support structure 7 form a ventilation path, and the air flowing in from the opening surface 22 passes through the impeller 21 and then passes through the radiator 10. Since the electric vehicle drive device 1 also includes the housing 27, the flow path for air flowing in and out of the impeller 21 can be further limited, and the air supply efficiency of the fan 28 is improved, so that the electric vehicle drive device 1 can be cooled more effectively.

[0069] The fan 28 that rotates the impeller 21 to form an air flow path is generally classified into an axial flow type, a diagonal flow type, a centrifugal type, and a cross flow type. In each type, the flow path of the air flowing into the impeller 21 and the flow path of the air flowing out of the impeller 21 are different. Therefore, the electric vehicle drive device 1 includes a housing 27 that matches each type. Hereinafter, a structural example of the electric vehicle drive device 1 including the housing 27 will be described.

[0070] Fig.13 The fan 28 shown is a centrifugal fan (Sirocco fan). In the centrifugal fan, air flows into the impeller from one or both sides of the extension direction of the drive shaft. The air flowing into the impeller flows out from the fan in the radial direction. Fig.13 In the structure shown, the impeller 21 is not directly in contact with the final transmission gear shaft 6, but the impeller 21 is surrounded and the outer frame portion to which the impeller 21 is fixed is in contact with the final transmission gear shaft 6, and the impeller 21 and the outer frame portion rotate together with the final transmission gear shaft 6.

[0071] right Fig.13The structure of the housing 27 shown in the figure will be described. The electric vehicle driving device 1 includes a housing 27 on both sides of the final transmission gear shaft 6, one side in the Y direction and the other side in the Y direction. In order to form an air intake port 29 for inhaling air on the gear box 5 side and the support structure 7 side of the final transmission gear shaft 6 as a driving shaft, a housing 27 is provided on the other side in the Y direction with respect to the final transmission gear shaft 6, which is spaced at an arbitrary distance from the gear box 5 side and the support structure 7 side. The housing 27 has a throat 30 protruding to one side in the Y direction between the radiator 10 and the impeller 21. The throat 30 adjusts the direction of the airflow 21a. The air intake port 29 may be provided on only one side instead of on both sides of the gear box 5 side and the support structure 7 side. The housing 27 on one side in the Y direction with respect to the final transmission gear shaft 6 is provided along the periphery of the impeller 21 and extends toward one side in the Y direction of the radiator 10.

[0072] By fixing and installing the casing 27 on the electric vehicle driving device 1 in this way, a general centrifugal fan 28 is formed, thereby forming Fig.13 The airflow 21a shown in FIG. 2 can improve the air blowing efficiency of the fan 28. Since the air blowing efficiency of the fan 28 is improved, the electric vehicle driving device 1 can be cooled more effectively.

[0073] Fig.14 The fan 28 shown is a cross-flow type (cross-flow fan). In the cross-flow type, air flows into the impeller 21 from the radially outer side of the fan 28. The air flowing into the impeller 21 flows out from the fan 28 to the radially outer side. Fig.14 In the structure shown, the impeller 21 is not directly in contact with the final transmission gear shaft 6, but the impeller 21 is surrounded, the outer frame portion to which the impeller 21 is fixed is in contact with the final transmission gear shaft 6, and the impeller 21 rotates together with the outer frame portion and the final transmission gear shaft 6. The impeller 21 is provided in a portion between the gear box 5 and the support structure 7.

[0074] right Fig.14 The structure of the housing 27 shown in the figure will be described. The electric vehicle driving device 1 includes two housings 27. A housing 27 is provided between the radiator 10 and the impeller 21 to cover the portion between the radiator 10 and the impeller 21 on the other side in the Y direction. The housing 27 has a throat 30 protruding to one side in the Y direction on the other side in the Z direction. The other housing 27 is further provided with a structure located around the impeller 21 and abutting against the motor 2 on one side in the Y direction and the other side in the Z direction with respect to the final drive gear shaft 6.

[0075] By setting the housing 27 in this way, a smooth ventilation path for the airflow 21a to pass through is formed between the motor 2 and the impeller 21. In the cross-flow type, air is sucked from the circumference on the other side of the Y direction of the impeller 21 with the throat 30 as the boundary, and exhaust is discharged from the circumference on one side of the Y direction of the impeller 21, so that a two-dimensional unidirectional airflow can be generated, thereby forming a ventilation form with good efficiency with very low pressure loss. In addition, since there is no sedimentation part (accumulation part) on the inner side of the housing 27, it is easy to discharge rainwater and dust to the outside of the housing 27. In particular, even in the case where it is difficult to discharge rainwater and dust when the electric vehicle 9 is traveling forward, there is a case where it is easy to discharge rainwater and dust when the impeller 21 rotates in the reverse direction during reverse travel. In addition, in the housing 27 in the form of accumulating rainwater and dust on the inner side of the housing 27, it is desirable to provide an opening for discharging rainwater and dust at the bottom of the housing 27.

[0076] Fig.15 The fan 28 shown is of the cross-flow type (cross-flow fan) and is Fig.14 The structure shown is different from the cross-flow structure. Fig.14 and Fig.15 In the structure of , the setting position of the inverter 8 is different. Fig.15 In the embodiment, the inverter 8 is disposed on the other side of the final gear shaft 6 in the Z direction. The inverter 8, the motor 2, the gear box 5, the support structure 7 and the housing 27 form a ventilation path. Fig.15 The part of the inverter 8 shown on one side in the Z direction bears the Fig.14 The motor 2 shown abuts against a portion of the housing 27. In the manner of the fan 28, Fig.14 or Fig.15 In the case of the cross flow type shown, the throat 30 plays an important role in relation to the air delivery capacity of the fan 28 .

[0077] Fig.16 The fan 28 shown is of an axial flow type. In the axial flow type, air flows into the impeller from a portion on one side of the extension direction of the drive shaft. The air flowing into the impeller flows out from a portion on the other side of the extension direction of the drive shaft. Fig.16 In the structure shown, a plurality of impellers 21 are provided in direct contact with the final gear shaft 6, and the impellers 21 rotate integrally with the final gear shaft 6. The support structure 7 has an opening around the portion supporting the final gear shaft 6. The opening is an air intake port 29 for the air flowing into the impeller 21.

[0078] right Fig.16The structure of the housing 27 shown in FIG. 1 is described. The electric vehicle drive device 1 includes two housings 27. The inverter 8 is provided on the other side of the final drive gear shaft 6 in the Z direction. A housing 27 is provided to cover the portion between the radiator 10 and the inverter 8 on the other side of the Y direction relative to the final drive gear shaft 6. A housing 27 is also provided to cover the gap between the inverter 8 and the motor 2.

[0079] By providing the housing 27 in this way, a space surrounded by the housing 27, the inverter 8, and the motor 2, i.e., a ventilation path, is formed around the final drive gear shaft 6. The air sucked in from the air intake port 29 is pressurized by the rotation of the impeller 21, and is blown to a portion of the ventilation path that is a rear flow region of the impeller 21. Since a pressure difference is generated between the portion of the ventilation path and the air around the electric vehicle drive device 1, an airflow 21a is generated that uses the pressure difference as a driving force and passes through the radiator 10, thereby enabling the radiator 10 to be efficiently cooled.

[0080] In addition, Fig.13 In the structure of the electric vehicle driving device 1 shown, the housing 27 is provided so as to form the air intake port 29 for taking in air on the gear box 5 side and the support structure 7 side of the final drive gear shaft 6 as the driving shaft, but the present invention is not limited to this. Fig.13 In the structure of the electric vehicle driving device 1 shown in FIG. Fig.16 Similarly to the structure shown, an air intake port 29 for air to flow into the impeller 21 is provided around the portion of the support structure 7 that supports the final gear shaft 6 .

[0081] As described above, in the electric vehicle drive device 1 of embodiment 4, since it includes a casing 27 that covers the surrounding portion of the impeller 21 and forms a flow path for air flowing in and out of the impeller 21, the flow path for air flowing in and out of the impeller 21 can be further limited, and the air supply efficiency of the fan 28 can be improved, thereby enabling the electric vehicle drive device 1 to be cooled more effectively.

[0082] The supporting structure 7 has an opening portion around the portion that supports the final drive gear shaft 6. When the opening portion is an air intake port 29 for air flowing into the impeller 21, an axial flow fan 28 is formed, thereby generating an airflow 21a that is driven by a pressure difference and passes through the radiator 10, thereby effectively cooling the radiator 10.

[0083] Implementation method 5. An electric vehicle driving device 1 according to a fifth embodiment will be described. Fig.17This is a cross-sectional view schematically showing the electric vehicle driving device 1 according to the fifth embodiment, and is a view cut along the YZ plane. The electric vehicle driving device 1 according to the fifth embodiment is configured such that the pipe 14 a and the wiring 33 are arranged around the final gear shaft 6 .

[0084] In the electric vehicle driving device 1 shown in this embodiment, the motor 2 and the inverter 8 are electrically connected by the wiring 33. Around the final drive gear shaft 6 between the gear box 5 and the support structure 7, the pipe 14a, i.e., one or both of the pipes 14a1 and 14a2 and the wiring 33 are arranged. Fig.17 The electric vehicle driving device 1 shown comprises Figure 4 The electric vehicle driving device 1 has a pipe 14a1 connecting the radiator 10 and the inverter 8, and a pipe 14a2 connecting the inverter 8 and the motor 2. The surrounding area of ​​the final drive gear shaft 6 between the gear box 5 and the supporting structure 7 is a space 31, and the pipe 14a1 and the pipe 14a2 are accommodated in the space 31. Fig.17 In the electric vehicle driving device 1 shown, the wiring 33 connecting the motor 2 and the inverter 8 is also accommodated in the space 31. The structure is not limited to that in which both the pipe 14a and the wiring 33 are accommodated in the space 31, and a structure in which either one of them is accommodated in the space 31 is also possible. In addition, the wiring 33 accommodated in the space 31 is not limited to the wiring connecting the motor 2 and the inverter 8.

[0085] In the present embodiment, the space 31 is a portion surrounded by the gear box 5, the support structure 7, the radiator 10, the inverter 8, the motor 2, and the cover 23. The structure of the space 31 is not limited thereto, and when the electric vehicle driving device 1 further includes a housing 27, the space 31 may also be a portion surrounded by the housing 27.

[0086] The space 31 has a portion connected to the outside space through a gap and a ventilation opening of the cover 23. However, since the space 31 is surrounded by various components and the interior is protected, the space 31 is a portion that does not contact with external equipment or people, and therefore, the pipes 14a and wirings 33 accommodated in the space 31 are less likely to break due to contact. Therefore, by arranging the pipes 14a and wirings 33 in the space 31, the pipes 14a and wirings 33 can be protected from breaking due to contact.

[0087] In addition, when the space 31 contains relatively weak components such as the piping 14a and the wiring 33, when the electric vehicle drive device 1 is installed on the electric vehicle 9, there is no need to worry about contact with operators, operating equipment, tools, etc., and on-board operations can be easily performed. In addition, the piping 14a and the wiring 33 can be reliably protected from the external environment during driving. In addition, since the closer to the center of the electric vehicle drive device 1, the smaller the vibration, the smaller the exciting force applied to the piping 14a and the wiring 33 in the space 31 becomes, thereby reducing the failure of the piping 14a and the wiring 33 caused by the excitation. In addition, since the components used to suppress the exciting force can be reduced, the electric vehicle drive device 1 can be made lighter and smaller.

[0088] Implementation 6 An electric vehicle driving device 1 according to a sixth embodiment will be described. Fig.18 1 is a cross-sectional view showing an outline of the electric vehicle driving device 1 according to the sixth embodiment, and is a view obtained by cutting along the YZ plane. Fig.19 2 is a cross-sectional view showing the outline of the electric vehicle driving device 1, and is a view obtained by cutting along the YZ plane. Fig.18 In the figure, the Y direction is the direction of travel of the electric vehicle. Fig.19 In the figure, the other side of the Y direction is the traveling direction of the electric vehicle. In each figure, there is a road surface (not shown) on the other side of the Z direction. The electric vehicle driving device 1 of embodiment 6 is a structure including an air guide plate 32 at the lower end portion on the downstream side relative to the traveling direction of the electric vehicle.

[0089] The electric vehicle driving device 1 includes an air guide plate 32. The air guide plate 32 has an inclined portion 32a on the road surface side opposite to the traveling direction of the electric vehicle when the electric vehicle driving device 1 is installed on the electric vehicle, and approaches the road surface as the electric vehicle moves toward the opposite direction. With such a configuration, the running wind, i.e., the airflow 32b, which passes through the other side of the Z direction of the electric vehicle in the downstream direction, is pushed toward the road surface, so that the rear flow of the air guide plate 32 can be made into a negative pressure. Since the rear flow of the air guide plate 32 is made into a negative pressure, the air around the electric vehicle driving device 1, especially the air located vertically above the air guide plate 32 and behind the electric vehicle driving device 1, is attracted to the rear of the air guide plate 32, so that the air can be easily discharged to the downstream side of the electric vehicle.

[0090] A configuration example of the electric vehicle driving device 1 provided with the air guide plate 32 will be described. Fig.18In the electric vehicle driving device 1 shown, the motor 2 is arranged in the traveling direction of the electric vehicle, the radiator 10 is arranged on one side in the Z direction relative to the final transmission gear shaft 6, and the inverter 8 is arranged on the other side in the Z direction relative to the final transmission gear shaft 6 and is open on the other side in the Y direction relative to the final transmission gear shaft 6. The air guide plate 32 is arranged on the other side in the Z direction of the inverter 8 and is arranged on the part on the other side in the Y direction. The electric vehicle driving device 1 includes a housing 27 on the other side in the Y direction of the part between the impeller 21 and the radiator 10. The fan 28 is a cross-flow type.

[0091] By configuring in this way, the flow of air can be cut off on the side where the inverter 8 is provided, and the side where the radiator 10 is provided can be used as the air intake side. The air is discharged from the opening portion on the other side of the Y direction relative to the final transmission gear shaft 6. The inverter 8, the motor 2, the gear box 5 and the support structure 7 form a ventilation path, and a unidirectional airflow 21a can be formed. Since the unidirectional airflow 21a is formed, low-temperature air is stably supplied to the radiator 10, so that the electric vehicle drive device 1 can be cooled more effectively.

[0092] exist Fig.19 In the electric vehicle driving device 1 shown, the motor 2 is arranged on the opposite side of the traveling direction of the electric vehicle, the radiator 10 is arranged on one side in the Z direction relative to the final transmission gear shaft 6, the inverter 8 is arranged on the other side in the Z direction relative to the final transmission gear shaft 6, and the other side in the Y direction relative to the final transmission gear shaft 6 is an opening surface 22. The air guide plate 32 is arranged on the other side in the Z direction of the motor 2 and on one side in the Y direction. Fig.19 Other structures of the electric vehicle driving device 1 and Fig.15 The electric vehicle drive devices 1 shown have the same structure.

[0093] exist Fig.18 An electric vehicle driving device 1 and Fig.19 In the electric vehicle driving device 1, the direction of the airflow 21a passing through the radiator 10 is different, but as long as the unidirectional airflow 21a is formed, the direction of the airflow 21a can be arbitrary. In addition, the side provided with the opening in the ventilation path can be the side in the direction of travel of the electric vehicle or the side opposite to the direction of travel. In addition, the installation position of the electric vehicle driving device 1 can be the front side or the rear side of the electric vehicle.

[0094] 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, modifications, additions, or omissions of at least one component, and also including extraction of at least one component and combination with components of other embodiments.

[0095] Hereinafter, each embodiment of the present disclosure will be summarized and described as a supplement. (Note 1) An electric vehicle driving device, comprising: A motor having a rotating shaft; a gear box that accommodates a speed reduction mechanism connected to the rotating shaft and a differential mechanism connected to the speed reduction mechanism; A final transmission gear shaft, one side of which is connected to the differential mechanism; a supporting structure that supports the other side of the final drive gear shaft and is fixed to the motor; and a radiator, wherein the radiator cools the electric motor; The motor and the final transmission gear shaft are disposed opposite to each other with a gap therebetween. The extending direction of the final transmission gear shaft is defined as the X direction, the direction perpendicular to the X direction and in which the motor is provided relative to the final transmission gear shaft is defined as one side of the Y direction, and the direction perpendicular to the X direction and the Y direction is defined as the Z direction. The gear box is provided on one side of the motor and the final transmission gear shaft in the X direction, and the support structure is provided on the other side of the motor and the final transmission gear shaft in the X direction. The heat sink is arranged on any one direction side or any two directions side of the other side of the Y direction, the one side of the Z direction and the other side of the Z direction relative to the final transmission gear shaft. (Note 2) The electric vehicle driving device according to Supplement 1, wherein: The radiator is an air-cooled refrigerant cooler, and the electric vehicle drive device comprises: A coolant pump and a liquid storage tank connected in series with the air-cooled refrigerant cooler via a pipe through which a coolant as a refrigerant flows; and an inverter electrically connected to the motor and converting electric power, A coolant flow path is formed for the coolant contained in the above-mentioned liquid storage tank to circulate in the order of the above-mentioned coolant pump, the above-mentioned air-cooled refrigerant cooler, and the above-mentioned liquid storage tank. The portion of the pipe of the coolant flow path between the air-cooled refrigerant cooler and the reservoir tank is arranged to flow sequentially through the inverter and the motor in series or in parallel through the inverter and the motor in parallel. (Note 3) The electric vehicle driving device according to Supplement 1, wherein: The above radiator is an air-cooled refrigerant cooler. The electric vehicle driving device comprises: A coolant pump, a liquid storage tank, and a refrigerant-oil heat exchanger connected in series with the air-cooled refrigerant cooler via a pipe through which a coolant as a refrigerant flows; and an inverter electrically connected to the motor and converting electric power, A coolant flow path is formed for the coolant contained in the above-mentioned liquid storage tank to circulate in the order of the above-mentioned coolant pump, the above-mentioned air-cooled refrigerant cooler, the above-mentioned refrigerant-oil heat exchanger, and the above-mentioned liquid storage tank. A portion of the pipe of the coolant flow path between the air-cooling type refrigerant cooler and the refrigerant-oil heat exchanger is provided so as to pass through the inverter. (Note 4) The electric vehicle driving device according to Supplement 1, wherein: The radiator is an air-cooled oil cooler, and the electric vehicle drive device comprises: a coolant pump connected in series with the air-cooled oil cooler via a pipe through which a coolant serving as a refrigerant flows; and an inverter electrically connected to the motor and converting electric power, The coolant pump is arranged on the gear box. A coolant flow path is formed for circulating the coolant retained at the bottom of the gear box in the order of the coolant pump, the air-cooled oil cooler, and the gear box. The portion of the pipe of the coolant flow path between the air-cooled oil cooler and the gear box is arranged to flow sequentially through the inverter and the motor in series or in parallel through the inverter and the motor in parallel. (Note 5) The electric vehicle driving device according to Supplement 1, comprising: a plurality of heat pipes, each of the plurality of heat pipes having a heat dissipating portion on one side and a heat receiving portion on the other side; and an inverter electrically connected to the motor and converting electric power, The heat sink is a heat dissipation part having a plurality of heat pipe heat dissipation fins. The heat receiving unit is thermally connected to one or both of the motor and the inverter. (Note 6) The electric vehicle driving device according to any one of Supplementary Notes 1 to 5, wherein the final gear shaft includes an impeller that rotates integrally with the final gear shaft. (Note 7) An electric vehicle driving device according to any one of Supplementary Notes 1 to 6, wherein: An inverter is included which is electrically connected to the motor and converts electric power. The heat sink is arranged on any one of the other side in the Y direction, one side in the Z direction, and the other side in the Z direction relative to the final transmission gear shaft. The inverter is disposed on any one of the other side in the Y direction, the one side in the Z direction, and the other side in the Z direction relative to the final drive gear shaft and is a side where the heat sink is not disposed. (Note 8) The electric vehicle driving device according to Supplementary Note 7, wherein: The Z direction is a vertical direction, one side of the Z direction is set as the vertical upper side, and the other side of the Z direction is set as the vertical lower side. The inverter is arranged on the other side of the Z direction relative to the final drive gear shaft. The inverter includes a cover that is detachable on the other side in the Z direction. (Note 9) An electric vehicle drive device according to Note 7 or 8, comprising a cover, wherein the cover has a ventilation opening for air flow in any one of the other side of the Y direction, the one side of the Z direction, and the other side of the Z direction relative to the above-mentioned final drive gear shaft and is a side on which the above-mentioned radiator and the above-mentioned inverter are not provided. (Note 10) The electric vehicle driving device according to any one of Supplementary Notes 7 to 9, wherein one or both of the electric motor and the inverter has a plurality of heat dissipation fins at a portion on the side of the final drive gear shaft. (Note 11) The electric vehicle driving device according to Supplementary Note 10, wherein: The inverter is arranged on one side of the Z direction or the other side of the Z direction relative to the final transmission gear shaft. The electric motor and the inverter are disposed with a gap therebetween. (Note 12) The electric vehicle driving device according to any one of Supplementary Notes 7 to 11, wherein the inverter has a plurality of heat dissipation fins at a portion on a side opposite to a side of the final drive gear shaft. (Note 13) The electric vehicle driving device according to Supplementary Note 6, further comprising a casing that covers a portion around the impeller and forms a flow path for air flowing into and out of the impeller. (Note 14) The electric vehicle driving device according to Supplement 13, wherein: The support structure has an opening around a portion supporting the final drive gear shaft. The opening portion serves as an air intake port for air flowing into the impeller. (Note 15) An electric vehicle driving device according to any one of Supplementary Notes 2 to 4, wherein: The electric motor and the inverter are electrically connected via wiring, and one or both of the pipe and the wiring are arranged around the final drive gear shaft between the gear box and the support structure. (Note 16) An electric vehicle drive device according to any one of Notes 1 to 15, wherein, when the electric vehicle drive device is installed on the electric vehicle, the portion on the road surface side opposite to the traveling direction of the electric vehicle includes a wind deflector, and the wind deflector has an inclined portion that approaches the road surface as the electric vehicle travels toward the side opposite to the traveling direction of the electric vehicle.

Claims

1. An electric vehicle driving device, characterized in that: include: an electric motor having a rotating shaft; a gear box that accommodates a speed reduction mechanism connected to the rotating shaft and a differential mechanism connected to the speed reduction mechanism; A final transmission gear shaft, one side of which is connected to the differential mechanism; A supporting structure, the supporting structure supports the other side of the final transmission gear shaft and is fixed to the motor; as well as a radiator, wherein the radiator cools the electric motor, The motor and the final transmission gear shaft are disposed opposite to each other with a gap therebetween. The extending direction of the final transmission gear shaft is defined as an X direction, the direction perpendicular to the X direction and in which the motor is provided relative to the final transmission gear shaft is defined as one side of the Y direction, and the direction perpendicular to the X direction and the Y direction is defined as a Z direction. The gear box is provided on one side of the motor and the final transmission gear shaft in the X direction, and the support structure is provided on the other side of the motor and the final transmission gear shaft in the X direction. The heat sink is disposed on any one direction side or any two directions side of the other side in the Y direction, one side in the Z direction, and the other side in the Z direction relative to the final drive gear shaft.

2. The electric vehicle driving device according to claim 1, characterized in that: The radiator is an air-cooled refrigerant cooler, The electric vehicle driving device comprises: A coolant pump and a liquid storage tank connected in series with the air-cooled refrigerant cooler via a pipe through which a coolant as a refrigerant flows; and an inverter electrically connected to the motor and converting electric power, A coolant flow path is formed for the coolant contained in the liquid storage tank to circulate in the order of the coolant pump, the air-cooled refrigerant cooler, and the liquid storage tank. The portion of the pipe of the coolant flow path between the air-cooled refrigerant cooler and the reservoir tank is arranged to flow sequentially through the inverter and the motor in series or in parallel through the inverter and the motor in parallel.

3. The electric vehicle driving device according to claim 1, characterized in that: The radiator is an air-cooled refrigerant cooler, The electric vehicle driving device comprises: A coolant pump, a liquid storage tank, and a refrigerant-oil heat exchanger connected in series with the air-cooled refrigerant cooler via a pipe through which a coolant as a refrigerant flows; and an inverter electrically connected to the motor and converting electric power, A coolant flow path is formed for the coolant contained in the liquid storage tank to circulate in the order of the coolant pump, the air-cooled refrigerant cooler, the refrigerant-oil heat exchanger, and the liquid storage tank. A portion of the pipe of the coolant flow path between the air-cooling type refrigerant cooler and the refrigerant-oil heat exchanger is provided so as to pass through the inverter.

4. The electric vehicle driving device according to claim 1, characterized in that: The radiator is an air-cooled oil cooler. The electric vehicle driving device comprises: a coolant pump connected in series with the air-cooled oil cooler via a pipe through which a coolant serving as a refrigerant flows; and an inverter electrically connected to the motor and converting electric power, The coolant pump is arranged in the gear box. A coolant flow path is formed for circulating the coolant retained at the bottom of the gear box in the order of the coolant pump, the air-cooled oil cooler, and the gear box. The portion of the pipe of the coolant flow path between the air-cooled oil cooler and the gear box is arranged to flow sequentially through the inverter and the motor in series or in parallel through the inverter and the motor in parallel.

5. The electric vehicle driving device according to claim 1, characterized in that: include: A plurality of heat pipes, each of the plurality of heat pipes having a heat dissipating portion on one side and a heat receiving portion on the other side; as well as an inverter electrically connected to the motor and converting electric power, The heat sink is the heat dissipation part having a plurality of heat pipe heat dissipation fins. The heat receiving unit is thermally connected to one or both of the motor and the inverter.

6. The electric vehicle driving device according to claim 1, characterized in that: The final drive gear shaft has an impeller that rotates integrally with the final drive gear shaft.

7. The electric vehicle driving device according to any one of claims 1 to 6, characterized in that: comprising an inverter electrically connected to the motor and converting electric power, The heat sink is arranged on any one of the other side in the Y direction, one side in the Z direction, and the other side in the Z direction relative to the final transmission gear shaft. The inverter is disposed on any one side of the other side in the Y direction, one side in the Z direction, and the other side in the Z direction relative to the final drive gear shaft and is a side where the heat sink is not disposed.

8. The electric vehicle driving device according to claim 7, characterized in that: The Z direction is a vertical direction, one side of the Z direction is set as the vertical upper side, and the other side of the Z direction is set as the vertical lower side. The inverter is arranged on the other side of the Z direction relative to the final transmission gear shaft. The inverter includes a cover that is detachable on the other side in the Z direction.

9. The electric vehicle driving device according to claim 7, characterized in that: A cover is included, which has a ventilation opening for air flow in any one of the other side in the Y direction, the one side in the Z direction and the other side in the Z direction relative to the final drive gear shaft and the side where the radiator and the inverter are not arranged.

10. The electric vehicle driving device according to claim 7, characterized in that: One or both of the motor and the inverter may include a plurality of heat dissipation fins at a portion on the final gear shaft side.

11. The electric vehicle driving device according to claim 10, characterized in that: The inverter is arranged on one side of the Z direction or the other side of the Z direction relative to the final transmission gear shaft. The motor and the inverter are arranged with a gap therebetween.

12. The electric vehicle driving device according to claim 7, characterized in that: The inverter has a plurality of heat dissipation fins at a portion on a side opposite to a side of the final drive gear shaft.

13. The electric vehicle driving device according to claim 6, characterized in that: A casing is included, which covers the periphery of the impeller and forms a flow path for air flowing into and out of the impeller.

14. The electric vehicle driving device according to claim 13, characterized in that: The support structure has an opening around a portion supporting the final gear shaft. The opening portion serves as an air intake port for air flowing into the impeller.

15. The electric vehicle driving device according to any one of claims 2 to 4, characterized in that: The motor and the inverter are electrically connected via wiring, One or both of the pipe and the wiring are arranged around the final gear shaft between the gear box and the support structure.

16. The electric vehicle driving device according to claim 1, characterized in that: When the electric vehicle driving device is installed in the electric vehicle, the portion on the road surface side opposite to the traveling direction of the electric vehicle includes a wind deflector having an inclined portion that approaches the road surface as the electric vehicle travels toward the side opposite to the traveling direction.

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