Drive system for a motor vehicle

Abstract

The invention relates to a drive system (1) for a motor vehicle (2), said drive system comprising: a first axle drive train (4) which drives a first vehicle axle (3) and is accommodated in a first drive train housing (13) and has a first electric machine (5) and a first transmission arrangement (7) forming a first structural unit (6) with the first electric machine (5); and a second axle drive train (9) which drives a second vehicle axle (8) and is accommodated in a second drive train housing (14) and has a second electric machine (10) and a second transmission arrangement (12) forming a second structural unit (11) with the second electric machine (10), wherein the first electric machine (5) and the second electric machine (10) as well as the first transmission arrangement (7) and the second transmission arrangement (12) are substantially identically constructed, wherein the first axle drive train (4) and the second axle drive train (9) are positioned in the drive system (1) so as to be rotated through an angle of 10-90° with respect to one another in relation to the axes of rotation of the associated electric machines (5, 10), and the first drive train housing (13) defines a first oil sump (16) storing a first oil (15), and the second drive train housing (14) defines a second oil sump (18) storing a second oil (17), wherein the holding volume of the first oil sump (16) corresponds to between 0.75-1.25 of the holding volume of the second oil sump (18).

Description

[0001] Drive system for a motor vehicle

[0002] The present invention relates to a drive system for a motor vehicle comprising a first axle drive train, which drives a first vehicle axle and is accommodated in a first drive train housing, having a first electric machine and a first transmission arrangement forming a first structural unit with the first electric machine, and a second axle drive train, which drives a second vehicle axle and is accommodated in a second drive train housing, having a second electric machine and a second transmission arrangement forming a second structural unit with the second electric machine, wherein the first electric machine and the second electric machine as well as the first transmission arrangement and the second transmission arrangement are of substantially identical construction.

[0003] Electric motors are increasingly being used to power motor vehicles, creating alternatives to combustion engines that require fossil fuels. Considerable efforts have already been made to improve the everyday suitability of electric drives and also to provide users with the same level of driving comfort they are accustomed to.

[0004] A detailed description of an electric drive can be found in an article in the magazine ATZ 113th year, 05 / 2011, pages 360-365 by Erik Schneider, Frank Fickl, Bernd Cebulski and Jens Liebold with the title: Highly integrated and flexible electric drive unit for electric vehicles. This article describes a drive unit for one axle of a vehicle which comprises an electric motor which is arranged concentrically and coaxially to a bevel gear differential, with a switchable 2-speed planetary gear set being arranged in the power train between the electric motor and bevel gear differential, which is also positioned coaxially to the electric motor or the bevel gear differential or spur gear differential. The drive unit is very compact and, thanks to the switchable 2-speed planetary gear set, allows a good compromise between climbing ability, acceleration and energy consumption.Such drive units are also referred to as electric axles or electrically operated axle drive trains. DE 10 2010 048 837 A1 discloses such a drive device comprising at least one electric motor and at least one planetary differential drivable by a rotor of the electric motor. The planetary differential comprises at least one planetary carrier operatively connected to a rotor of the electric motor, first planetary gears and second planetary gears rotatably mounted on the planetary carrier, and a first sun gear and a second sun gear, each of which is operatively connected to an output shaft of the planetary differential. The first planetary gears mesh with the first sun gear, and each of the second planetary gears meshes with the second sun gear and with one of the first planetary gears. Furthermore, the sun gears are arranged coaxially with a rotational axis of the rotor.

[0005] An axial flux machine is a dynamoelectric machine in which the magnetic flux between the rotor and stator runs parallel to the rotor's axis of rotation. Both the stator and rotor are often largely disk-shaped. Axial flux machines are particularly advantageous when the axial space available in a given application is limited. This is often the case, for example, with the electric drive systems for electric or hybrid vehicles described above.

[0006] In addition to the shorter axial length, another advantage of the axial flux machine is its comparatively high torque density. This is due to the larger air gap area available in a given installation space compared to radial flux machines. Furthermore, a smaller iron volume is required compared to conventional machines, which has a positive effect on the machine's efficiency.

[0007] Typically, an axial flux machine comprises at least one stator with windings for generating the axially aligned magnetic field. At least one rotor is equipped with permanent magnets, for example, whose magnetic field interacts with the magnetic field of the stator windings to generate a drive torque across an air gap.

[0008] In the development of electric motors and transmissions intended for electric axles, there is a continuing need to increase their power densities, making the necessary cooling, especially of the electric motors and transmissions, increasingly important. Due to the necessary cooling performance, hydraulic fluids, such as cooling oils, have become the standard in most concepts for dissipating heat from the thermally stressed areas of an electric motor and / or transmission.

[0009] The gears typically found in these electric axles are generally lubricated with gear oil, which is often also used as cooling oil for the electric motor. To reliably deliver the lubricant or cooling oil to the various lubrication or cooling points, a corresponding hydraulic fluid circuit is installed in the corresponding electric axles.

[0010] It is therefore quite common to create an oil sump within an electric axle to store the amount of oil required for lubrication and cooling, from which the above-mentioned hydraulic fluid circuit is fed with oil.

[0011] Especially in fully electric drive concepts for motor vehicles, it is becoming increasingly common to equip both vehicle axles with an electrically operated axle drive train. To save costs, there is a continuing need to install as many identical parts as possible in the respective axle drive trains of the front and rear axles.

[0012] It is therefore the object of the invention to eliminate or at least mitigate the problems known from the prior art and to realize a drive system for a motor vehicle with two axle drive trains that can be manufactured cost-effectively and to provide an effective and cost-effective cooling system. This object is achieved by a drive system for a motor vehicle comprising a first axle drive train, which drives a first vehicle axle and is accommodated in a first drive train housing, with a first electric machine and a first transmission arrangement forming a first structural unit with the first electric machine, and a second axle drive train, which drives a second vehicle axle and is accommodated in a second drive train housing, with a second electric machine and a second transmission arrangement forming a second structural unit with the second electric machine,wherein the first electric machine and the second electric machine as well as the first transmission arrangement and the second transmission arrangement are of substantially identical construction, wherein the first axle drive train and the second axle drive train are arranged in the drive system rotated by an angle of 10-90° to one another with respect to the rotational axes of the respective electric machines, and the first drive train housing defines a first oil sump storing a first oil, and the second drive train housing defines a second oil sump storing a second oil, wherein the receiving volume of the first oil sump corresponds to between 0.75-1.25 of the receiving volume of the second oil sump.

[0013] This provides the advantage of providing a drive system with two axle drive trains that, despite the different installation positions of the axle drive trains, offers high efficiency thanks to hydraulic cooling while maintaining the highest possible degree of uniformity. The drive system according to the invention allows for different axial positions of the two axle drive trains relative to one another simply by using different drive train housings. This allows, for example, a first axle drive train to be arranged in the front axle area with optimal installation space, and a second axle drive train, rotated relative to the first, to be arranged in the rear axle area with optimal installation space, even though virtually the same components (electric motor, transmission arrangement) are used.First, the individual elements of the claimed subject matter of the invention are explained in the order in which they appear in the set of claims, and subsequently particularly preferred embodiments of the subject matter of the invention are described.

[0014] The drive system according to the invention comprises at least two electrically operable axle drive trains for driving two vehicle axles, each axle drive train being assigned to a vehicle axle. An electrically operable axle drive train comprises an electric machine and a transmission assembly coupled to the electric machine. The transmission assembly and the electric machine form a structural unit. This can be formed, for example, by a drive train housing in which the transmission assembly and the electric machine are jointly accommodated. The drive train housing can be designed as a single-piece or multi-piece unit.

[0015] For example, it would also be possible for the electric machine to have a motor housing and / or the transmission to have a transmission housing, with the structural unit then being achieved by fixing the transmission relative to the electric machine. In such a case, the motor housing and the transmission housing form part of the drivetrain housing.

[0016] The motor housing of one of the electric machines and / or a transmission housing of one of the transmission assemblies can also each be accommodated in a drive train housing. The drive train housing is preferably formed from a metallic material, particularly preferably from aluminum, gray cast iron, or cast steel, particularly by means of a primary forming process such as casting or die casting. In principle, however, it would also be possible to form the drive train housing from a plastic. The drive train housing can particularly preferably have a pot-like basic shape so that the electric machine and the transmission assembly can be inserted into the drive train housing via the open end thereof. The transmission housing is a housing for accommodating a transmission assembly.Its task is to guide existing shafts via the bearings and to grant the wheels (and possibly cams) the degrees of freedom they require under all loads without hindering their rotational and possibly path-related movement, as well as to absorb bearing forces and support moments. A gearbox housing can be single- or multi-shell, i.e., undivided or split. In particular, the gearbox housing should also dampen noise and vibrations and be able to safely accommodate lubricant. The gearbox housing is preferably made of a metallic material, particularly preferably aluminum, gray cast iron, or cast steel, in particular using a primary forming process such as casting or die-casting. The gearbox housing can be made of one or more parts.

[0017] The motor housing encloses the electric machine. A motor housing can also accommodate the control and power electronics. The motor housing can also be part of a cooling system for the electric machine and be designed in such a way that cooling fluid can be supplied to the electric machine via the motor housing and / or heat can be dissipated to the outside via the housing surfaces. Furthermore, the motor housing protects the electric machine and any electronics from external influences.

[0018] A motor housing can, in particular, be formed from a metallic material. Advantageously, the motor housing can be formed from a metallic cast material, such as die-cast aluminum, die-cast magnesium, gray cast iron, or cast steel. The motor housing can be constructed in one or more parts.

[0019] An electric machine in an axle drive train of a drive system serves to convert electrical energy into mechanical energy and / or vice versa. It typically comprises a stationary part known as a stator, stand, or armature, and a part known as a rotor or runner, which is movable, particularly rotatable, relative to the stationary part. An electric machine can be designed as a radial flux machine or an axial flux machine.

[0020] An electric machine of an axle drive train of the drive system according to the invention is preferably designed as an axial flux machine. The magnetic flux in an electric axial flux machine (AFM) is directed axially in the air gap between the stator and rotor relative to a rotational direction of the rotor of the axial flux machine. There are different types of axial flux machines. One known type is a so-called I-arrangement, in which the rotor is arranged axially next to a stator or between two stators. Another known type is a so-called H-arrangement, in which two rotors are arranged on opposite axial sides of a stator. The electric axial flux machine is preferably configured as an I-type.

[0021] In principle, it is also possible for a plurality of I-type and / or H-type rotor-stator configurations to be arranged axially next to one another. In this context, it would also be possible to arrange one or more I-type rotor-stator configurations and one or more H-type rotor-stator configurations next to one another in the axial direction. In particular, it is also preferable for the H-type and / or I-type rotor-stator configurations to be essentially identical in design, so that they can be combined in a modular manner to form an overall configuration. Such rotor-stator configurations can, in particular, be arranged coaxially to one another and connected to a common rotor shaft or to multiple rotor shafts.

[0022] In particular, the electric machine is dimensioned such that vehicle speeds greater than 50 km / h, preferably greater than 80 km / h, and in particular greater than 100 km / h can be achieved. The electric motor particularly preferably has an output greater than 30 kW, preferably greater than 50 kW, and in particular greater than 70 kW. It is further preferred that the electric machine provides speeds greater than 5,000 rpm, particularly preferably greater than 10,000 rpm, and most particularly preferably greater than 12,500 rpm. Motor vehicles within the meaning of this application are land vehicles that are moved by mechanical power without being tied to railway tracks. A motor vehicle can, for example, be selected from the group of passenger cars (PKW), trucks (HGVs), mopeds, light motor vehicles, motorcycles, buses (KOM), or tractors.

[0023] The transmission arrangement can be coupled, in particular, to an associated electric motor of the axle drive train, which is designed to generate a drive torque for the motor vehicle. The drive torque is particularly preferably a main drive torque, so that the motor vehicle is driven exclusively by the drive torque. The transmission arrangement is preferably designed as a planetary gear, most preferably as a switchable, in particular two-speed planetary gear.

[0024] An electric machine of an axle drive train of the drive system can further comprise a control device. A control device, as can be used in the present invention, serves in particular for the electronic control and / or regulation of one or more technical systems of one of the electric machines.

[0025] A control device preferably has a wired or wireless signal input for receiving electrical signals, such as sensor signals. Furthermore, a control device preferably also has a wired or wireless signal output for transmitting electrical signals, in particular.

[0026] Control and / or regulation operations can be performed within the control device. It is particularly preferred that the control device comprises hardware configured to execute software. The control device preferably comprises at least one electronic processor for executing program sequences defined in software. The control device may further comprise one or more electronic memories in which the data contained in the signals transmitted to the control device can be stored and read out again. Furthermore, the control device may comprise one or more electronic memories in which data can be stored in a modifiable and / or unmodifiable manner.

[0027] A control device can comprise a plurality of control units, which are arranged, in particular, spatially separated from one another in the motor vehicle. Control units are also referred to as Electronic Control Units (ECUs) or Electronic Control Modules (ECMs) and preferably have electronic microcontrollers for performing computing operations for processing data, particularly preferably using software. The control units can preferably be networked with one another, enabling wired and / or wireless data exchange between control units. In particular, it is also possible to network the control units with one another via bus systems present in the motor vehicle, such as the CAN bus or LIN bus.

[0028] Most preferably, the control device has at least one processor and at least one memory, which in particular contains a computer program code, wherein the memory and the computer program code are configured, with the processor, to cause the control device to execute the computer program code.

[0029] The control device can particularly preferably comprise power electronics for supplying current to a stator or rotor of an electrical machine assigned to it. Power electronics is preferably a combination of various components which control or regulate a current to the electrical machine, preferably including the peripheral components required for this purpose, such as cooling elements or power supplies. In particular, the power electronics contains one or more power electronics components which are designed to control or regulate a current. These are particularly preferably one or more power switches, e.g. power transistors. The power electronics particularly preferably has more than two, particularly preferably three, separate phases or current paths, each with at least one separate power electronics component.The power electronics are preferably designed to control or regulate a power with a peak power, preferably continuous power, of at least 10 W, preferably at least 100 W, particularly preferably at least 1000 W per phase.

[0030] An electric machine of an axle drive train of the drive system is preferably dimensioned such that vehicle speeds greater than 50 km / h, preferably greater than 80 km / h, and in particular greater than 100 km / h can be achieved. The electric motor particularly preferably has an output greater than 30 kW, preferably greater than 50 kW, and in particular greater than 70 kW. It is further preferred that the electric machine provide speeds greater than 5,000 rpm, particularly preferably greater than 10,000 rpm, and most preferably greater than 12,500 rpm.

[0031] Advantageous embodiments of the invention are specified in the dependent claims. The features listed individually in the dependent claims can be combined with one another in a technologically expedient manner and can define further embodiments of the invention. Furthermore, the features specified in the claims are further specified and explained in the description, where further preferred embodiments of the invention are presented.

[0032] According to an advantageous embodiment of the invention, it can be provided that a first oil pump is arranged in the first oil sump, which pumps the first oil from the first oil sump to the first electrical machine and / or to the first transmission arrangement and / or a second oil pump is arranged in the second oil sump, which pumps the second oil from the second oil sump to the second electrical machine and / or to the second transmission arrangement.

[0033] The advantage of this design is that an oil pump in an oil sump can be operated particularly quietly because it is acoustically insulated or sound-damped by the oil surrounding it. According to a further preferred development of the invention, it can also be provided that the first drive train housing defines a first gear chamber for accommodating the first gear arrangement, from which first gear chamber the first oil can be conveyed into the first oil sump via a first oil outlet opening and / or the second drive train housing defines a second gear chamber for accommodating the second gear arrangement, from which second oil can be conveyed into the second oil sump via a second oil outlet opening. This can initially result in a structural separation of the gear chamber and the oil sump.This means that the gear assembly no longer engages directly with the oil sump, allowing the gear assembly to operate with the lowest possible splash losses, which leads to significant increases in the efficiency of the corresponding gear assembly. For example, a spur gear can, at most, divert oil accumulating in the gear chamber during operation of the gear assembly from the gear chamber into the oil sump via the corresponding oil outlet opening. The separation of the chambers also makes it easier to maintain an optimal oil level in the associated oil sump.

[0034] Furthermore, according to a likewise advantageous embodiment of the invention, as already outlined above, it can also be provided in particular that the first gear arrangement has a first gearwheel which is rotatable axially parallel to the axis of rotation of the first electrical machine and by means of which the first oil located in the first gear chamber can be conveyed out of the first gear chamber through the first oil outlet opening into the first oil sump and / or the second gear arrangement has a second gearwheel which is rotatable axially parallel to the axis of rotation of the second electrical machine and by means of which the second oil located in the second gear chamber can be conveyed out of the second gear chamber through the second oil outlet opening into the second oil sump.

[0035] According to another particularly preferred embodiment of the invention, the first gearwheel may have a first rotational axis arranged above the first oil outlet opening in the direction of gravity, and / or the second gearwheel may have a second rotational axis arranged above the second oil outlet opening in the direction of gravity. This allows, in particular, a good scooping effect of oil from the gear chamber into the corresponding oil sump to be achieved.

[0036] Furthermore, the invention can also be further developed in such a way that the first gearwheel is partially enclosed in the circumferential direction by a channel-like, circular-ring-shaped first housing section of the first drive train housing and / or the second gearwheel is partially enclosed in the circumferential direction by a channel-like, circular-ring-shaped second housing section of the second drive train housing.

[0037] The advantage of this design is that, on the one hand, churning losses can be further reduced and the scooping effect of the corresponding gear can be further improved.

[0038] In a likewise preferred embodiment of the invention, it can also be provided that the first drive train housing is constructed in multiple parts and / or the second drive train housing is constructed in multiple parts. This allows for improved adaptability of the drive train housing to the installation space requirements and, at the same time, further increases component uniformity through the use of identical housing elements.

[0039] It may also be advantageous to further develop the invention in such a way that the first drive train housing comprises a first motor housing for receiving the first electric machine and a first transmission housing for receiving the first transmission arrangement, wherein the first oil sump is formed in and / or on the first transmission housing and / or the second drive train housing comprises a second motor housing for receiving the second electric machine and a second transmission housing for receiving the second transmission arrangement, wherein the second oil sump is formed in and / or on the second transmission housing, which can also further increase the uniformity of the housing components, since necessary component variants are reduced to the transmission housings.

[0040] According to a further preferred embodiment of the

[0041] According to the subject matter of the invention, it can be provided that the first electrical machine has a first control unit for supplying current to the first electrical machine and the second electrical machine has a second control unit for supplying current to the second electrical machine, wherein the first control unit and the second control unit are essentially identical in construction, which can also contribute to an increased uniformity of the drive system.

[0042] Finally, the invention can also be advantageously implemented such that the first axle drive train comprises two first electric machines arranged coaxially to one another, axially directly adjacent to one another, each in an axial flux configuration, and / or the second axle drive train comprises two second electric machines arranged coaxially to one another, axially directly adjacent to one another, each in an axial flux configuration. The advantage resulting from this is, in particular, that an axially very compact axle drive train can be provided, via which the two vehicle wheels of a vehicle axle can be driven by an associated electric machine, each improving the driving dynamics and stability of the drive system.

[0043] The invention will be explained in more detail below with reference to figures without limiting the general inventive concept.

[0044] It shows:

[0045] Figure 1 shows a drive system of a motor vehicle with two axle drive trains in a schematic block diagram,

[0046] Figure 2 shows the drive system known from Figure 2 with a perspective view of the two axle drive trains,

[0047] Figure 3 shows the first axle drive train in a schematic cross-sectional view,

[0048] Figure 4 shows the second axle drive train in a schematic cross-sectional view. Figure 1 shows a drive system 1 for a motor vehicle 2, comprising a first axle drive train 4, which drives a first vehicle axle 3 and is accommodated in a first drive train housing 13, with a first electric machine 5 and a first transmission arrangement 7 forming a first structural unit 6 with the first electric machine 5.

[0049] The drive system 1 further comprises a second axle drive train 9, which drives a second vehicle axle 8 and is accommodated in a second drive train housing 14, with a second electric machine 10 and a second transmission arrangement 12 which forms a second structural unit 11 with the second electric machine 10.

[0050] The first electric machine 5 and the second electric machine 10 as well as the first gear arrangement 7 and the second gear arrangement 12 are essentially of identical construction.

[0051] In the embodiment shown in Figure 1, the first axle drive train 4 has two first electric motors 5 arranged coaxially to one another, axially directly adjacent to one another, each in an axial flux configuration. Similarly, the second axle drive train 9 also has two second electric motors 10 arranged coaxially to one another, axially directly adjacent to one another, each in an axial flux configuration. As a result, each vehicle wheel of the motor vehicle 2 can be driven by an electric motor 5, 10.

[0052] Due to the different installation space situation on the two vehicle axles 3, 8, the first axle drive train 4 and the second axle drive train 9 are arranged in the drive system 1 rotated by an angle of 10-90° to each other with respect to the rotation axes of the respective electric machines 5, 10, which can be seen particularly clearly in Figure 2.

[0053] The first drive train housing 13 defines a first oil sump 16 storing a first oil 15, while the second drive train housing 14 provides a second oil sump 18 storing a second oil 17, wherein the receiving volume of the first oil sump 16 corresponds to between 0.75 and 1.25 of the receiving volume of the second oil sump 18. The oils 16, 17 and their fill levels are indicated by a dotted line in Figures 3-4. A first oil drain opening 36 and a second oil drain opening 35 are provided on the bottom side of the oil sumps 16, 18 in the direction of gravity.

[0054] From Figures 3-4 it can also be seen that a first oil pump 33 is arranged in the first oil sump 16, which pumps the first oil 15 from the first oil sump 16 to the first electrical machine 5 and to the first transmission arrangement 7. And a second oil pump 19 is arranged in the second oil sump 18, which pumps the second oil 17 from the second oil sump 18 to the second electrical machine 10 and to the second transmission arrangement 12.

[0055] The first drive train housing 13 defines a first gear chamber 20 for accommodating the first gear assembly 7, from which the first oil 15 can be conveyed into the first oil sump 16 via a first oil outlet opening 21, as shown in Figure 3. Similarly, Figure 4 shows that the second drive train housing 14 defines a second gear chamber 22 for accommodating the second gear assembly 12, from which the second oil 17 can be conveyed into the second oil sump 18 via a second oil outlet opening 23.

[0056] The first gear arrangement 7 further comprises a first gearwheel 34 which is rotatable axially parallel to the rotational axis of the first electric machine 5 and through which the first oil 15 located in the first gear chamber 20 can be conveyed from the first gear chamber 20 through the first oil outlet opening 21 into the first oil sump 16. The second gear arrangement 12 also comprises a second gearwheel 24 which is rotatable axially parallel to the rotational axis of the second electric machine 10 and through which the second oil 17 located in the second gear chamber 22 can be conveyed from the second gear chamber 22 through the second oil outlet opening 23 into the second oil sump 18.

[0057] The first gear 34 further has a first rotational axis, which is arranged above the first oil outlet opening 21 in the direction of gravity. The second gear 24 also has a second rotational axis, which is arranged above the second oil outlet opening 23 in the direction of gravity, which can again be clearly seen from the combined view of Figures 3-4.

[0058] Figure 3 further shows that the first gear 34 is partially enclosed in the circumferential direction by a channel-like, annular-section-shaped first housing section 25 of the first drive train housing 13, while, as shown in Figure 4, the second gear 24 is also partially enclosed in the circumferential direction by a channel-like, annular-section-shaped second housing section 26 of the second drive train housing 14.

[0059] It is therefore also clearly evident from the exemplary embodiments in Figures 3-4 how the installation space separation between the oil sumps 16, 18 and the gear chambers 20, 22 can be designed.

[0060] Figure 3 also shows that the first drive train housing 13 comprises a first motor housing 27 for accommodating the first electric machine 5 and a first transmission housing 28 for accommodating the first transmission arrangement 7, wherein the first oil sump 16 is formed in and / or on the first transmission housing 28. The second drive train housing 14 analogously has a second motor housing 29 for accommodating the second electric machine 10 and a second transmission housing 30 for accommodating the second transmission arrangement 12, wherein the second oil sump 18 is formed in and / or on the second transmission housing 30, as can be seen from Figure 4.

[0061] It is also evident from Figure 3 that the first electrical machine 5 has a first control unit 31 for supplying current to the first electrical machine 5 and the second electrical machine 10 - as shown in Figure 4 - has a second control unit 32 for supplying current to the second electrical machine 10, wherein the first control unit 31 and the second control unit 32 are substantially identical in construction.

[0062] The terms radial, axial, tangential and circumferential direction used in this application always refer to the axis of rotation of the corresponding electrical machine. The terms left, right, top, bottom, above and below are used here only to clarify which areas of the figures are currently being described in the text. The later embodiment of the invention can also be arranged differently. Furthermore, the invention is not limited to the embodiments shown in the figures. The above description is therefore not to be regarded as restrictive, but as explanatory. The following patent claims are to be understood in such a way that a named feature is present in at least one embodiment of the invention. This does not exclude the presence of further features.If the patent claims and the above description define 'first' and 'second' features, this designation serves to distinguish between two similar features without establishing a ranking.

[0063] List of reference symbols

[0064] 1 drive system

[0065] 2 motor vehicles

[0066] 3 first vehicle axle

[0067] 4 first axle drive train

[0068] 5 first electric machine

[0069] 6 Unit

[0070] 7 first gear arrangement

[0071] 8 second vehicle axle

[0072] 9 second axle drive train

[0073] 10 second electric machine

[0074] 11 Unit

[0075] 12 second gear arrangement

[0076] 13 first drive train housing

[0077] 14 second drive train housing

[0078] 15 first oil

[0079] 16 first oil sump

[0080] 17 second oil

[0081] 18 second oil sump

[0082] 19 second oil pump

[0083] 20 first gear compartment

[0084] 21 first oil outlet opening

[0085] 22 second gear compartment

[0086] 23 second oil outlet opening

[0087] 24 second gear

[0088] 25 first housing section

[0089] 26 second housing section

[0090] 27 first engine housing

[0091] 28 first gearbox housing

[0092] 29 second engine housing

[0093] 30 second gearbox housing

[0094] 31 first control unit

[0095] 32 second control unit first oil pump first gear second oil drain opening first oil drain opening

Claims

Claims Drive system (1) for a motor vehicle (2) comprising a first axle drive train (4) driving a first vehicle axle (3) and housed in a first drive train housing (13), comprising a first electric machine (5) and a first transmission arrangement (7) forming a first structural unit (6) with the first electric machine (5), and a second axle drive train (9) driving a second vehicle axle (8) and housed in a second drive train housing (14), comprising a second electric machine (10) and a second transmission arrangement (12) forming a second structural unit (11) with the second electric machine (10), wherein the first electric machine (5) and the second electric machine (10) as well as the first transmission arrangement (7) and the second transmission arrangement (12) are essentially identical in construction, characterized in thatthat the first axle drive train (4) and the second axle drive train (9) are arranged in the drive system (1) rotated by an angle of 10-90° relative to each other with respect to the axes of rotation of the respective electric machines (5, 10), and the first drive train housing (13) defines a first oil sump (16) containing a first oil (15), and the second drivetrain housing (14) defines a second oil sump (18) containing a second oil (17), wherein the receiving volume of the first oil sump (16) is between 0.75-1.25 of the receiving volume of the second oil sump (18).

2. Drive system (1) according to claim 1, characterized in that a first oil pump (33) is arranged in the first oil sump (16), which pumps the first oil (15) from the first oil sump (16) to the first electric machine (5) and / or to the first gear arrangement (7) and / or a second oil pump (19) is arranged in the second oil sump (18), which pumps the second oil (17) from the second oil sump (18) to the second electric machine (10) and / or to the second gear arrangement (12).

3. Drive system (1) according to one of the preceding claims, characterized in that the first drivetrain housing (13) defines a first gear chamber (20) for receiving the first gear assembly (7), from which the first oil (15) can be conveyed into the first oil sump (16) via a first oil outlet opening (21) and / or the second drivetrain housing (14) defines a second gear chamber (22) for receiving the second gear assembly (12), from which the second oil (17) can be conveyed into the second oil sump (18) via a second oil outlet opening (23).

4. Drive system (1) according to claim 3, characterized in that the first gear arrangement (7) has a first gear (34) rotatable parallel to the axis of rotation of the first electric machine (5), through which the first oil (15) located in the first gear chamber (20) can be conveyed from the first gear chamber (20) through the first oil outlet opening (21) into the first oil sump (16) and / or the second gear arrangement (12) has a second gear (24) rotatable parallel to the axis of rotation of the second electric machine (10), through which the second oil (17) located in the second gear chamber (22) can be conveyed from the second gear chamber (22) through the second oil outlet opening (23) into the second oil sump (18).Drive system (1) according to claim 3 or 4, characterized in that the first gear (34) has a first axis of rotation which is arranged in the direction of gravity above the first oil outlet opening (21) and / or the second gear (24) has a second axis of rotation which is arranged in the direction of gravity above the second oil outlet opening (23). Drive system (1) according to any one of the preceding claims, characterized in that the first gear (34) is circumferentially encompassed by a channel-like, annular segment-shaped first housing section (25) of the first drive train housing (13) and / or the second gear (24) is circumferentially encompassed by a channel-like, annular segment-shaped second housing section (26) of the second drive train housing (14). Drive system (1) according to one of the preceding claims, characterized in that the first drivetrain housing (13) is formed in multiple parts and / or the second drivetrain housing (14) is formed in multiple parts. Drive system (1) according to one of the preceding claims, characterized in that the first drivetrain housing (13) comprises a first motor housing (27) for receiving the first electric machine (5) and a first gearbox housing (28) for receiving the first gearbox assembly (7), wherein the first oil sump (16) is formed in and / or on the first gearbox housing (28) and / or the second drivetrain housing (14) comprises a second motor housing (29) for receiving the second electric machine (10) and a second gearbox housing (30) for receiving the second gearbox assembly (12), wherein the second oil sump (18) is formed in and / or on the second gearbox housing (30).Drive system (1) according to one of the preceding claims, characterized in that the first electric machine (5) has a first control unit (31) for supplying current to the first electric machine (5) and the second electric machine (10) has a second control unit (32) for supplying current to the second electric machine (10), wherein the first control unit (31) and the second control unit (32) are essentially identical in construction. Drive system (1) according to one of the preceding claims, characterized in that. the first axle drive train (4) comprises two first electrical machines (5) arranged coaxially to each other, axially directly adjacent to each other, each in an axial flux configuration and / or the second axle drive train (9) comprises two second electrical machines (10) arranged coaxially to each other, axially directly adjacent to each other, each in an axial flux configuration.

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