Cooling arrangement for an electric drive

Abstract

The present invention relates to a cooling arrangement (1) for an electric drive of a vehicle, comprising a housing (2), an electric machine (5) having a stator (6), a rotor (7) rotatably mounted in the housing (2) with respect to the stator (6), and a rotor shaft (8) rigidly connected to the rotor (7), a transmission (9) having an intermediate shaft (10) and a differential (11), and an oil supply system, characterized in that the oil supply system has a transmission oil chamber (12), an engine oil chamber (13), an engine sump (14), a transmission sump (15), and is designed such that oil is guided from the engine oil chamber (13) by gravity via the electric machine (5) into the engine sump (14) and the transmission sump (15), and is guided from the transmission sump (15) via the transmission oil chamber (12) into the engine oil chamber (13) by movements of the transmission (9).

Description

[0001] The invention relates to a cooling arrangement for an electric drive of a vehicle, in particular a motor vehicle. The cooling arrangement comprises a housing that forms a motor compartment and a transmission compartment. The cooling arrangement includes an electric machine located in the motor compartment, comprising a stator, a rotor rotatably mounted in the housing relative to the stator, and a rotor shaft rigidly connected to the rotor. The cooling arrangement includes a transmission located in the transmission compartment, comprising an intermediate shaft meshing with the rotor shaft and a differential meshing with the intermediate shaft. The cooling arrangement includes an oil supply system. The oil supply system serves to cool and / or lubricate the electric machine and / or the transmission.

[0002] To ensure the continuous operation of electric axle systems, the waste heat generated by losses must be dissipated as efficiently as possible. In most cases, oil is used for this purpose, to directly transfer the heat from its source. Examples of such sources include the stator and rotor of the drive motor, as well as bearings and gears in the gearbox. The oil primarily conducts the heat away from the source and distributes it throughout the system.

[0003] Oil supply systems for cooling and / or lubricating an electric drive are already known from the prior art. For example, DE 10 2015 013 976 A1 and DE 10 2010 004 222 A1 disclose a so-called passive oil supply system for cooling and lubricating an electrically operated drive train.

[0004] DE 10 2018 203 696 A1 discloses an oil reservoir for a system with a lubricating oil circuit and a cooling oil circuit, in particular for a vehicle drive train with a gearbox and / or bearings lubricated by a lubricating oil circuit and an electric machine cooled by a cooling oil circuit, characterized in that the oil reservoir is designed to divide oil into the lubricating oil circuit and the cooling oil circuit.

[0005] DE 10 2021 208 654 A1 discloses a drive device having the following features: a motor having a motor shaft extending in an axial direction; a gear mechanism connected on one side in the axial direction of the motor shaft; a locking mechanism that restricts driving of the gear mechanism; a housing that accommodates the motor, the gear mechanism and the locking mechanism; oil stored in the housing;and an oil channel for circulating the oil, the housing comprising: an engine compartment for housing the engine, a gear compartment for housing the transmission mechanism and the locking mechanism, and a partition provided between the engine compartment and the gear compartment, and the oil channel comprising: a pump for pumping the oil in the oil channel, a first supply flow channel for supplying the oil to the engine, and a second supply flow channel for supplying the oil to the locking mechanism.

[0006] German patent application DE 10 2022 105 286 A1 discloses a drive device consisting of a motor section with a rotor, a motor shaft, and a radially external stator; a gearbox section axially adjacent to the motor section; and a housing containing both sections. The gearbox section has two shafts, a first and a second, each connected to a motor shaft. Several gears are attached to the shafts: a first gear on the first shaft and a second and third gear on the second shaft. These gears mesh with each other and with a fourth gear on a third axis of rotation. The housing comprises a motor housing and a gearbox housing, separated from each other by a partition, and also contains an inverter housing with an electrical inverter unit for the stator.The arrangement of the gears in relation to the shafts, as well as the positions of the axes of rotation and partitions, are specific to the functionality of the units within the housing structure.

[0007] US Patent 2023 / 0087205A1 discloses a power unit consisting of a housing and rotor iron core, a rotating shaft, a gear set, and an oil pump system arranged within the housing, wherein the rotating shaft is attached to the rotor iron core, a drive gear in the gear set is attached to the rotating shaft, and the rotating shaft has a cooling oil channel; the housing has an oil collection basin and an oil collection tank, part of a structure of a first gear in the gear set is located in the oil collection basin, and the oil collection tank is located on one side of the rotating shaft that is away from the oil collection basin and is designed to collect cooling oil carried out of the oil collection basin as the gear set rotates; and the oil collection tank connects to the cooling oil channel via a first oil channel, wherein the cooling oil in the oil collection tank flows through the first oil channel into the cooling oil channel;and the oil pumping system includes an oil pump, an oil inlet channel of the oil pump communicates with the oil collection basin, and an oil outlet channel of the oil pump communicates with the cooling oil channel.

[0008] WO 2019 / 194 072 A1 shows a motor unit connected to a motor, the motor unit comprising: - a generator that produces electricity using the power of the engine; - an electric motor; - a transmission mechanism that transfers power between the engine, the generator and the electric motor and delivers the power of the engine and the electric motor from an output shaft; - a housing equipped with a storage space to accommodate the generator, electric motor and transmission mechanism; - Oil that accumulates in the lower part of the storage area; and - a pump component that is provided on the transmission mechanism and is driven by the power of the motor.

[0009] A primary oil path and a secondary oil path for oil circulation are present in the storage compartment. The primary oil path carries the oil from a lower area of ​​the storage compartment into the interior of the electric motor. The secondary oil path includes: - a suction path that connects from a lower area of ​​the storage space to a suction port of the pump section; and - a first branching path and a second branching path that branch off from each other at the outlet of the pump part.

[0010] The first branch extends from the outlet directly over the electric motor, carrying oil from the top of the motor into it. The second branch carries oil from the outlet to the generator. The transmission mechanism has a motor drive shaft that extends along a motor axis and rotates through the motor. The motor drive shaft is a hollow shaft with an internal cavity. The first and second branches run through this cavity. The generator has: - a rotor that is attached to the motor drive shaft; and - a stator that surrounds the rotor.

[0011] A generator shaft, housing the generator, and a gearbox shaft, containing the transmission mechanism, are located within the casing's storage space. The casing has a partition section that separates the generator shaft and the gearbox shaft. The pump section is held by this partition section.

[0012] The object of the invention is to provide a particularly efficient oil supply system for cooling and / or lubricating an electric drive.

[0013] This problem is solved by a cooling arrangement with the features of claim 1. Advantageous further developments are the subject of the dependent claims.

[0014] Accordingly, the problem is solved by a cooling arrangement for an electric drive of a vehicle, in particular a motor vehicle. The cooling arrangement comprises a housing that forms a motor compartment and a transmission compartment preferably axially adjacent to it. The cooling arrangement includes an electric machine located in the motor compartment, comprising a stator, a rotor rotatably mounted in the housing relative to the stator, and a rotor shaft rigidly connected to the rotor. The cooling arrangement includes a transmission located in the transmission compartment, comprising an intermediate shaft meshing with the rotor shaft and a differential meshing with the intermediate shaft. The cooling arrangement includes an oil supply system. The oil supply system serves in particular to cool and / or lubricate the electric machine and / or the transmission by means of oil.

[0015] The oil supply system comprises a transmission oil chamber, preferably located directly above the transmission; an engine oil chamber, preferably located higher than the transmission oil chamber and preferably located directly above the electric motor; an engine sump, preferably located directly below the electric motor; and a transmission sump, preferably located directly below the transmission. The oil supply system is designed such that oil is drawn from the engine oil chamber by gravity, via the electric motor, into the engine sump and the transmission sump, and from the transmission sump, via the transmission oil chamber, into the engine oil chamber by the movement of the transmission. "Above / higher" and "below / lower" refer to a vertical positioning that is determined by the installation configuration of the cooling system and the electric motor, respectively.

[0016] In other words, the cooling system employs a passive cooling concept, in which the oil is pumped in a two-stage process within the gearbox compartment to an oil chamber, or motor oil chamber, located above the electric motor or electric machine. Due to the geodetic height difference, the oil flows onto the windings or stator windings of the electric motor, thus cooling hotspots. The oil then flows into a sump, or motor / gearbox sump, below the electric motor. From there, it returns to the gearbox compartment via a heat exchanger.

[0017] This has the advantage that a novel lubrication concept can be provided for the internal cooling and / or lubrication of the electric drive, which is designed as a passive oil supply system, is particularly efficient and can ensure sufficient cooling and / or lubrication of the electric drive with a simple design.

[0018] According to a preferred embodiment, the housing can have cooling fins arranged in the area of ​​the engine sump and / or transmission sump and projecting outwards for preferably exclusively cooling the oil by means of ambient air.

[0019] Alternatively or additionally, the cooling arrangement can include a water heat exchanger located in the area of ​​the engine sump and / or transmission sump for cooling the oil.

[0020] In other words, the cooling system is designed so that the electric drive is cooled either exclusively by ambient air or additionally by a water heat exchanger located in the underbody. This means that the cooling system specifically lacks a water jacket and an active oil supply system.

[0021] According to a preferred embodiment, the oil supply system can have a (first) oil guide contour, preferably formed by the housing and opening into the transmission oil chamber. The oil supply system can be designed such that the oil from the transmission sump is preferably conveyed into the transmission oil chamber exclusively by the movements of the transmission and the arrangement of the oil guide contour. Rotation of the differential, against gravity, first conveys the oil along a (narrow) guide between an inner wall of the housing and the differential, and then along the (first) oil guide contour into the transmission oil chamber.

[0022] According to the preferred embodiment, the differential can have an input gear meshing with the intermediate shaft, the rotation of which pumps the oil along the oil guide contour against gravity into the transmission oil chamber.

[0023] According to a preferred embodiment, the oil supply system can have a (second) oil guide contour, preferably formed by the housing and opening into the engine oil chamber. The oil supply system can be designed such that the oil is conveyed from the transmission oil chamber to the transmission by gravity and from the transmission preferably exclusively by the movements of the transmission and the arrangement of the oil guide contour into the engine oil chamber. Rotation of the intermediate shaft conveys the oil against gravity along the (second) oil guide contour into the engine oil chamber. The oil guide contour can be essentially S-shaped.

[0024] According to the preferred embodiment, the intermediate shaft can have an input gear meshing with the rotor shaft, the rotation of which pumps the oil along the oil guide contour against gravity into the engine oil chamber. This means that the oil is transported into the engine oil chamber by a close guide between the input gear of the intermediate shaft and the oil guide contour on the housing.

[0025] According to the preferred embodiment, the transmission oil chamber can have an overflow, which is preferably located directly above the input gear of the intermediate shaft. This ensures that the oil can escape from the transmission oil chamber when it reaches a predetermined fill level.

[0026] According to one embodiment, the motor oil chamber can have outlet openings. These outlet openings can be located, in particular, directly above the electric motor, especially in the area of ​​the stator windings. This allows for direct cooling of the electric motor.

[0027] According to a preferred embodiment, the engine oil chamber can have a stepped bottom section that separates a first, particularly higher, bottom section of the engine oil chamber from a second, particularly lower, bottom section. The oil guide contour can open into the engine oil chamber in the area of ​​the first bottom section, and the outlet openings can be located in the area of ​​the second bottom section of the engine oil chamber. This prevents the oil from flowing back through the oil guide contour into the transmission compartment.

[0028] According to a preferred embodiment, the engine oil chamber can have vertically oriented partitions and / or dividers. This ensures a defined oil flow behavior even when cornering.

[0029] According to a preferred embodiment, the engine oil chamber can be formed in multiple parts, in particular by the housing and a cover separate from the housing.

[0030] According to a preferred embodiment, the motor oil chamber can be divided into two chambers, with the oil guide contour opening into a first chamber of the two chambers and the outlet openings being located in a second chamber of the two chambers. The first chamber and the second chamber are essentially separated from each other and connected to each other via a channel. The first chamber forms a buffer zone to ensure a continuous supply of oil to the electric motor for cooling.

[0031] According to a preferred embodiment, the oil supply system can have an oil collection channel, preferably formed by the housing, which is arranged and designed such that the oil from the gearbox oil chamber, in particular from the overflow, is collected and directed into the rotor shaft. Furthermore, the gearbox oil chamber can have an opening above a rotor shaft bearing and / or the rotor shaft teeth. This ensures sufficient cooling and / or lubrication of the rotor shaft bearing and the teeth.

[0032] According to a preferred embodiment, the rotor shaft can have circumferential openings in the area of ​​the electric machine for cooling the spraying stator windings.

[0033] In other words, the present disclosure relates to a so-called top-down cooling concept in which the waste heat generated by losses is dissipated as efficiently as possible. This is a purely passive cooling system, and unlike the prior art, it does not use a water jacket or an active oil supply system to cool the electric motor. The cooling arrangement comprises an electric motor (drive source) and a reduction gearbox in an offset configuration. In the first step, oil is pumped from a common sump of the electric motor and gearbox through the differential into a first oil chamber in the gearbox. Once this first oil chamber reaches a certain fill level, the oil flows onto the large gear of the intermediate shaft. From there, it is pumped upwards into a second oil chamber above the electric motor.Due to the geodetic height difference, the oil flows through bores onto the windings of the electric motor, thus cooling the hotspots. The oil then returns to a sump beneath the electric motor. From there, it flows back into the gearbox via a heat exchanger. The lower part of the housing is shown with fins representing the heat exchanger, but this can also be implemented as a water-based heat exchanger. The first oil chamber within the gearbox also has bores. The oil escaping from these bores is used both to lubricate the bearings and gear contacts, and to allow an oil flow into the rotor shaft. This oil flow cools the rotor, lubricates the rotor bearing on the outside, and optionally (via bores in the shaft) provides additional cooling of the winding heads using spin-spray cooling.The rotor shaft has the unique feature of being supported at only two points. The drive housing consists of at least three parts (gearbox cover, system housing, motor cover), each with various functions. In the first step, oil is pumped from a shared sump for the electric motor and gearbox through the differential into a first oil chamber within the gearbox. This transport is facilitated by a tight oil channel between the differential and the housing wall and a primary guide contour. This primary guide contour can be an integral part of the gearbox cover or a separate component. Once the first oil chamber reaches a certain fill level, the oil flows over an overflow onto the large gear of the intermediate shaft. From there, it is pumped upwards into a second oil chamber above the electric motor.To ensure efficient oil flow through the gear, a second guide contour is required above the gear. This second guide contour can be an integral part of the system housing or a separate component. The incoming oil flows over a small step to prevent it from flowing back from the chamber into the gearbox. Additional vertical baffles / ribs can be inserted into the oil chamber to maintain consistent oil flow during cornering. Due to the geodetic height difference, the oil flows through bores onto the electric motor windings, thus cooling the hotspots. The oil then returns to a sump below the electric motor. A heat exchanger carries the oil back to the gearbox. The lower part of the housing is shown as an example of the ribs representing the heat exchanger.This can also be implemented as a water heat exchanger. The first oil chamber also contains bores. The oil escaping from these bores is used both to lubricate the bearings and gear contacts, and to allow an oil flow into the rotor shaft. This oil flow into the shaft is introduced via an oil collection channel, which is also integrated into the housing. This oil flow cools the rotor, lubricates the rotor bearing on the outside, and optionally (via bores in the shaft, not shown here) provides additional cooling for the winding heads. The guide contours and chambers in the gearbox can also be manufactured and integrated as separate components (e.g., made of plastic). A ribbed design is incorporated on the underside of the system housing to optimize heat dissipation to the environment.The finning can be integrated into the system housing or designed as a separate component. The heat exchanger can optionally be mounted on the underside (or a finned heat exchanger plate) of the electric drive according to the invention, as an alternative to finning. A cooling medium can be routed through the cooling water connections, which additionally cools the oil in the sump. The system can be expanded by integrating additional power electronics. The cooling water flow between the power electronics and the heat exchanger can thus be advantageously integrated.

[0034] The invention is explained below with the help of figures. These show: Fig. 1 a perspective sectional view of a cooling arrangement according to the present disclosure, Fig. 2 and Fig. 3 schematic representations of preferred embodiments of the cooling arrangement, Fig. 4 a sectional view of the cooling arrangement, Fig. 5 and Fig. 6 perspective views of individual components of the cooling arrangement, in particular a gearbox cover of a housing and individual gearbox components of a gearbox, Fig. 7 to 9 perspective views of individual details of the cooling arrangement, Fig. 10 and Fig. 11 perspective views of a water heat exchanger of the cooling arrangement, and Fig. 12 to 14 an alternative design of an engine oil chamber of the cooling arrangement, Fig. 15 to 18 different views of a part of the housing, especially the gearbox cover, and Fig. 19 to 24 different views of the cooling arrangement.

[0035] The figures are purely schematic and serve to illustrate the invention. The same elements are identified by the same reference symbols.

[0036] Features of the different designs can be freely interchanged.

[0037] Fig. Figure 1 shows a perspective sectional view of a cooling arrangement 1 according to the present disclosure. Fig. 2 and Fig. Figure 3 shows schematic representations of preferred embodiments of the cooling arrangement 1. Fig. Figure 4 shows a sectional view of the cooling arrangement 1. The cooling arrangement 1 is used in an electric drive of a vehicle, in particular a motor vehicle. Individual details of the cooling arrangement 1 are shown in Fig. Numbers 5 to 9 are shown.

[0038] The cooling arrangement 1 comprises a housing 2. The housing 2 forms a motor compartment 3 and a gearbox compartment 4 preferably axially adjacent thereto. In particular, the housing 2 can be multi-part, especially consisting of at least three separate parts, namely a gearbox cover, a system housing, and a motor cover. The system housing is hollow and has an axial opening on the gearbox side and an axial opening on the motor side. The gearbox-side axial opening is closed by the gearbox cover. The gearbox cover is screwed axially to the system housing. The motor-side axial opening is closed by the motor cover. The motor cover is screwed axially to the system housing.

[0039] The cooling arrangement 1 includes an electric machine 5. The electric machine 5 is arranged in the motor compartment 3. The electric machine 5 has a stator 6, a rotor 7 rotatably mounted in the housing 2 relative to the stator 6, and a rotor shaft 8 rigidly connected to the rotor 7. The rotor shaft 8 has a gear toothing on the transmission side. The electric machine 5 is specifically designed as a radial flux machine. The rotor shaft 8 is specifically (only) supported by two rotor shaft bearings.

[0040] The cooling arrangement 1 includes a gearbox 9. The gearbox 9 is arranged in the gearbox compartment 4. The gearbox 9 has an intermediate shaft 10 meshing with the rotor shaft 8 (in particular the rotor shaft teeth) and a differential 11 meshing with the intermediate shaft 10.

[0041] The cooling arrangement 1 includes an oil supply system. The oil supply system serves in particular to cool and / or lubricate the electric machine 5 and / or the gearbox 9 by means of oil.

[0042] The oil supply system includes a gearbox oil chamber 12, an engine oil chamber 13, an engine sump 14 and a gearbox sump 15.

[0043] The transmission oil chamber 12 is arranged above the transmission 9, in particular directly above the transmission 9. The motor oil chamber 13 is arranged above the electric machine 5, in particular directly above the electric machine 5. Preferably, the motor oil chamber 13 is arranged higher than the transmission oil chamber 12.

[0044] The motor sump 14 is arranged below the electric machine 5, in particular directly below the electric machine 5. The transmission sump 15 is arranged below the transmission 9, in particular directly below the transmission 9. Preferably, the motor sump 14 is arranged higher than the transmission sump 15. The motor sump 14 and the transmission sump 15 can be combined, i.e., formed as sections of a bottom area of ​​the housing 2 or merging into one another.

[0045] The cooling arrangement 1 or the housing 2 has outwardly projecting cooling fins 16 for preferably exclusively cooling the oil by means of ambient air. The cooling fins 16 are arranged particularly in the area of ​​the engine sump 14 and / or transmission sump 15. Alternatively or additionally, the cooling arrangement 1 can have a water heat exchanger 17 for cooling the oil (see Figure 1). Fig. 10 and Fig. 11). The water heat exchanger 17 is located, in particular, in the area of ​​the engine sump 14 and / or transmission sump 15. The heat exchanger 17 has, in particular, cooling water connections (see Figure 11). Fig. 10). In addition, the heat exchanger 17 features, in particular, a cooling water channel in the base plate (see Fig. 11). The heat exchanger 17 is sealed in particular to the housing 2, in particular to the system housing.

[0046] The cooling arrangement 1 can house a power electronics unit 18 (see below). Fig. 3) exhibit. The power electronics 18 can be mounted axially on the outside of the housing 2 on the motor side and be cooled by the oil supply system.

[0047] The differential 11 has an input gear 21 which engages with the intermediate shaft 10 and two output shafts 22.

[0048] The intermediate shaft 10 has an input gear 23 that meshes with the rotor shaft 8 or the rotor shaft teeth, and an output gear 24 that meshes with the differential 11 or the input gear 21. Preferably, the input gear 23 can have a larger diameter than the output gear 24.

[0049] To transport the oil through the movements of the gearbox 9, the oil supply system has, in particular, a (first) oil guide contour 20, preferably formed by the housing 2 and opening into the gearbox oil chamber 12. The first oil guide contour 20 is, in particular, Fig. 5 and Fig. 6 clearly visible. By rotating the input gear 21 of the differential 11, the oil is first pumped against gravity along a (narrow) guide between an inner housing wall and the input gear 21 and then along the first oil guide contour 20 into the transmission oil chamber 12 (cf. Fig. 5).

[0050] Preferably, the transmission oil chamber 12 can have an overflow 25. The overflow 25 can be located above the intermediate shaft 10 or the input gear 23, preferably directly above the intermediate shaft 10. When the oil level in the transmission oil chamber 12 exceeds a predetermined level, the oil flows out of the overflow 25 and onto the intermediate shaft 10.

[0051] The oil supply system is designed such that the oil from the gearbox oil chamber 12 is preferably guided exclusively into the engine oil chamber 13 by the movements of the gearbox 9.

[0052] To transport the oil through the movements of the transmission 9, the oil supply system has, in particular, a (second) oil guide contour 26, preferably formed by the housing 2 and opening into the engine oil chamber 13. The second oil guide contour 26 is, in particular, Fig. 7 and Fig. 8 clearly visible. By rotating the input gear 23 of the intermediate shaft 10, the oil is conveyed against gravity along the second oil guide contour 26 into the engine oil chamber 13 (cf. Fig. 7 and Fig. 8). The second oil guide contour 26 can be essentially S-shaped.

[0053] The oil supply system can be designed such that the oil from the engine oil chamber 13 is guided by gravity via the electric machine 5 into the engine sump 14 and the transmission sump 15.

[0054] In particular, the motor oil chamber 13 can have outlet openings 27. The outlet openings 27 can be arranged, in particular, directly above the electric machine 5, especially in the area (of stator windings) of the stator 6.

[0055] Furthermore, the engine oil chamber 13 can have a bottom-side step 28 that separates a first, in particular higher, bottom section 29 of the engine oil chamber 13 from a second, in particular lower, bottom section 30 of the engine oil chamber 13. The second oil guide contour 26 can open into the engine oil chamber 13 in the area of ​​the first bottom section 29, and the outlet openings 27 can be arranged in the area of ​​the second bottom section 30 of the engine oil chamber 13 (see Figure 1). Fig. 8 and Fig. 9). Although not shown, the engine oil chamber may have 13 vertically oriented partitions and / or dividers.

[0056] Preferably, the oil supply system can have an oil collection channel 31, preferably formed by the housing 2. The oil collection channel 31 can be arranged and designed such that the oil from the gear oil chamber 12, in particular from the overflow 25, is collected and guided into the (hollow) rotor shaft 8 (see Figure 1). Fig. 4) In addition, the rotor shaft 8 can have circumferential openings 32 in the area of ​​the electric machine 5 for cooling the spraying stator windings.

[0057] Fig. Figures 12 to 14 show an alternative design of the engine oil chamber 13. The engine oil chamber 13 is formed by the housing 2 (or the system housing or a base body of the system housing) and by a cover 33 (see Figure 12 to 14). Fig. 14) closed. The motor oil chamber 13 is divided into a first chamber 34 and a second chamber 35. The first chamber 34 and the second chamber 35 are essentially separate from each other and connected via a channel 36 (formed by a tube). The cover 33 has a separating web 37 that separates the first chamber 34 and the second chamber 35 from each other. The first chamber 35 forms a buffer zone to ensure a continuous supply of oil to the electric motor 5. The outlet openings 27 are located in a bottom area of ​​the second chamber 35.

[0058] Fig. Figures 15 to 18 show a portion of the housing 2, namely the gearbox cover, in various perspective views. The design of the gearbox oil chamber 12 and the first oil guide contour 20 are particularly well illustrated. The gearbox cover is a multi-part structure comprising a base body 38 and a separate chamber cover 39. The chamber cover 39 is axially screwed to the base body 38. The base body 38 has a shell-like structure (with a substantially closed base formed by a gearbox cover side wall and an axially projecting rim), the depth of which corresponds essentially to the width of the input gear 21 of the differential 11. In particular, the input gear 21 (as well as the output gear 24 of the intermediate shaft 10) is axially accommodated within the base body 38.

[0059] The base body 36 forms a web 40 that projects axially from the side wall of the transmission cover and separates a first (lower) transmission cover interior, in which the differential 11 (or the input gear 21) and the intermediate shaft 10 (or the output gear 24) are arranged, from a second (upper) transmission cover interior, in which the transmission oil chamber 12 is arranged. The second transmission cover interior is open to the first transmission cover interior to allow oil inflow. The web 40 forms a bottom boundary of the first oil guide contour 20 and the transmission oil chamber 12. A bottom 41 of the transmission oil chamber 12 is offset vertically downwards relative to a bottom 42 of the first oil guide contour 20. The chamber cover 39 forms a lateral boundary of the first oil guide contour 20 and the transmission oil chamber 12.In this arrangement, a side wall 43 of the transmission oil chamber 12 is axially offset inwards from a side wall 44 of the first oil guide contour 20. The overflow 25 is formed in the chamber cover 39. The overflow 25 is designed as a lateral or radial opening 45, or an opening oriented towards the differential 11 and the intermediate shaft 10 (i.e., not open in the axial direction and not open in the vertical direction). The outlet opening may also have an axial opening 46. The axial opening 46 may be smaller than the opening 45. The oil collection channel 31 is formed by the base body 38. The oil collection channel 31 may project axially further than the web 40.

[0060] Fig. Figures 19 to 24 show various perspective views and sectional views of cooling arrangement 1. Fig. 19 and Fig. 20 the base body 38 of the gearbox cover is not shown, so that the interior of the cooling arrangement 1 can be shown. Fig. Figure 19 shows the cooling arrangement 1 with lid 33 and chamber cover 39 mounted. Fig. Figure 20 shows an exploded view with separate lid 33 and separate chamber cover 39.

[0061] In Fig. In figures 21 to 24 it is particularly evident that the second oil guide contour 26 is formed section by section by the cover 33 and section by a base body of the system housing of the housing 2, whereby a smooth transition is realized (cf. Fig.22). In this case, a lower section 47 of the S-shaped second oil guide contour 26 is formed by the housing 2, and an upper section 48 of the S-shaped second oil guide contour 26 is formed by the cover 33. The lower section 47 extends along the intermediate shaft 10 or the output gear 24 of the intermediate shaft 10 over an arc section of 30° to 70°, in particular from 40° to 60°. The upper section 48 forms a side wall or part of the partition 37 of the engine oil chamber 13. Reference symbol list 1 Cooling arrangement 2 cases 3 Engine compartment 4 Gearbox compartment 5 electric machine 6 Stator 7 Rotor 8 Rotor shaft 9 gearboxes 10 Intermediate shaft 11 Differential 12 Gear oil chamber 13 Engine oil chamber 14 Engine sump 15 Gearbox sump 16 cooling fins 17 heat exchangers 18 Power Electronics 19 - 20 first oil guide contour 21 Input gear 22 Output shaft 23 Input gear 24 Output gear 25 Overflow 26 second oil guide contour 27 Outlet opening 28 levels 29 first floor section 30 second floor section 31 Oil drip tray 32 Opening 33 lids 34 first chamber 35 second chamber 36-channel 37 dividing bridge 38 basic bodies 39 chamber cover 40 Bridge 41 Bottom of the gearbox oil chamber 42 Bottom of the first oil guide contour 43 Side wall of the gearbox oil chamber 44 Side wall of the first oil guide contour 45 opening 46 Axial opening 47 lower section of the second oil guide contour 48 upper section of the second oil guide contour

Claims

[1] Cooling arrangement (1) for an electric drive of a vehicle, comprising a housing (2) forming a motor compartment (3) and a transmission compartment (4), an electric machine (5) arranged in the motor compartment (3) and comprising a stator (6), a rotor (7) rotatably mounted in the housing (2) with respect to the stator (6) and a rotor shaft (8) rigidly connected to the rotor (7), a transmission (9) arranged in the transmission compartment (4) and comprising an intermediate shaft (10) meshing with the rotor shaft (8) and a differential (11) meshing with the intermediate shaft (10), and an oil supply system for cooling and / or lubricating the electric machine (5) and / or the transmission (9), characterized by, that the oil supply system has a transmission oil chamber (12) arranged above the transmission (9), a motor oil chamber (13) arranged above the electric machine (5), a motor sump (14) arranged below the electric machine (5), a transmission sump (15) arranged below the transmission (9) and is designed such that oil from the motor oil chamber (13) is guided by gravity via the electric machine (5) into the motor sump (14) and the transmission sump (15) and from the transmission sump (15) is guided via the transmission oil chamber (12) into the motor oil chamber (13) by movements of the transmission (9). [2] Cooling arrangement (1) according to claim 1, characterized by, that the housing (2) has cooling fins (16) arranged in the area of ​​the engine sump (14) and / or transmission sump (15) and projecting outwards for cooling the oil by means of ambient air and / or that the cooling arrangement (1) has a water heat exchanger (17) arranged in the area of ​​the engine sump (14) and / or transmission sump (15) for cooling the oil. [3] Cooling arrangement (1) according to claim 1 or 2, characterized by , that the oil supply system has an oil guide contour (20) opening into the transmission oil chamber (12) and the oil supply system is designed such that the oil from the transmission sump (15) is preferably conveyed exclusively by the movements of the transmission (9) and the arrangement of the oil guide contour into the transmission oil chamber (12). [4] Cooling arrangement (1) according to claim 3, characterized by, that the differential (11) has an input gear (21) which is in tooth engagement with the intermediate shaft (10), by whose rotation the oil is conveyed along the oil guide contour (20) against gravity into the transmission oil chamber (12). [5] Cooling arrangement (1) according to any one of claims 1 to 4, characterized by , that the oil supply system has an oil guide contour (26) opening into the engine oil chamber (13) and the oil supply system is designed such that the oil is conveyed from the transmission oil chamber (12) to the transmission (9) by gravity and from the transmission (9) preferably exclusively by the movements of the transmission (9) and the arrangement of the oil guide contour (26) into the engine oil chamber (13). [6] Cooling arrangement (1) according to claim 5, characterized by, that the intermediate shaft (10) has an input gear (23) which engages with the rotor shaft (8), and by whose rotation the oil is conveyed along the oil guide contour (26) against gravity into the engine oil chamber (13). [7] Cooling arrangement (1) according to claim 6, characterized by , that the transmission oil chamber (12) has an overflow (25) which is located above the input gear (23) of the intermediate shaft (10). [8] Cooling arrangement (1) according to any one of claims 5 to 7, characterized by , that the engine oil chamber (13) has outlet openings (27) and a bottom-side step (28), wherein the step (28) separates a first bottom section (29) of the engine oil chamber (13) from a second bottom section (30) of the engine oil chamber (13), and wherein the oil guide contour (26) opens into the engine oil chamber (13) in the area of ​​the first bottom section (29), and the outlet openings (27) are arranged in the area of ​​the second bottom section (30) of the engine oil chamber (13). [9] Cooling arrangement (1) according to any one of claims 1 to 8, characterized by , that the oil supply system has an oil collection trough (31) which is arranged and designed in such a way that the oil from the gearbox oil chamber (12) is collected and directed into the rotor shaft (8). [10] Cooling arrangement (1) according to any one of claims 1 to 9, characterized by that the oil supply system has a pump and the oil supply system is designed such that the oil from the transmission sump (15) is pumped into the transmission oil chamber (12) and / or into the engine oil chamber (13).

Images