ELECTRIC DRIVE SYSTEM FOR A MOTOR VEHICLE, IN PARTICULAR FOR A MOTOR VEHICLE

Description

[0001] The invention relates to an electric drive system for a motor vehicle, in particular for a motor car, according to the preamble of claim 1.

[0002] German patent DE 10 2018 009 582 A1 discloses an electric axle drive for a motor vehicle, comprising at least one electric motor, a differential driven by the electric motor, and a first housing part that at least partially surrounds the differential gear. A second housing part, separate from the first, which at least partially surrounds the electric motor, is also disclosed. CN 205 468 311 U discloses a dump truck with an electric drivetrain. WO 2020 / 114827 A1 discloses an electric axle drive for a commercial vehicle. CN 106 382 349 A discloses a dual-motor transmission.

[0003] The object of the present invention is to create an electric drive system for a motor vehicle in such a way that a particularly compact design can be achieved.

[0004] This problem is solved by an electric drive system for a motor vehicle with the features of claim 1. Advantageous embodiments with expedient further developments of the invention are specified in the remaining claims.

[0005] The invention relates to an electric drive system for a motor vehicle, in particular for a car. This means that the motor vehicle, preferably designed as a car, and most preferably as a commercial vehicle, in its fully manufactured state has the electric drive system and can be driven by means of the electric drive system, in particular purely electrically.

[0006] In particular, the motor vehicle, in its fully manufactured state, has at least or exactly two axles arranged one behind the other in the longitudinal direction of the vehicle. Each axle has at least or exactly two wheels, also referred to as vehicle wheels, which are arranged, in particular, on opposite sides of the motor vehicle in the transverse direction. For example, the electric drive system is assigned to one of the axles, so that the wheels of the axle to which the electric drive system is assigned can be driven by means of the electric drive system. When the wheels are mentioned below, unless otherwise specified, this refers to the wheels of the axle to which the electric drive system is assigned that can be driven by means of the electric drive system.The wheels are the ground contact elements of the motor vehicle, which is supported or supported downwards by these ground contact elements against the ground in the vertical direction. When the motor vehicle is driven along the ground while supported downwards by its wheels, the wheels roll along the ground. To drive the motor vehicle along the ground, for example, the wheels, and thus the motor vehicle itself, are driven by the electric drive system. The electric drive system is therefore an electric drive device for, in particular, purely electric propulsion of the wheels and thus of the motor vehicle.

[0007] Where ordinal numbers, such as "first," "second," and so on, are used in this disclosure, they do not necessarily indicate an order, especially unless otherwise stated. Unless otherwise stated, ordinal numbers do not necessarily imply that multiple elements must be provided. In other words, the mention of a first element does not necessarily mean that a second element is or must be provided. Rather, ordinal numbers are used in this disclosure to conceptually distinguish, and thus to address, identical concepts to which they refer unambiguously and without contradiction.

[0008] The electric drive system comprises a first electric machine, which has a first rotor. For example, the first electric machine has a first stator, by means of which the first rotor can be driven and thus rotated about an axis of rotation of the first rotor relative to the first stator, also referred to as the first axis of rotation of the machine. The first electric machine can provide torque via the first rotor, in particular for driving the vehicle and especially for driving the wheels. The electric drive system also comprises a differential gear, also simply referred to as a differential, which has a differential gear designed, for example, as a ring gear or spur gear. The differential gear is a gear that has teeth, in particular external teeth.The torques available or provided by the first machine are transmitted to the differential gear via the differential gear, thereby enabling the differential gear to be driven. In particular, this allows the differential gear to rotate about its axis of rotation, also referred to as the differential gear axis, especially relative to the stator. It is particularly possible that the differential gear is assigned to the same axle as the electric drive system. Thus, for example, the wheels of one axle can be driven by the electric machine, especially by its rotor, via the differential gear.As is well known from the prior art, the differential gear is configured, for example, to transmit or distribute the respective torque provided by the first electric machine via the first rotor to the wheels. Furthermore, as is generally known, the differential gear is preferably configured to allow different wheel speeds, for example, when the vehicle is cornering, particularly while the wheels are driven or can be driven by the first electric machine, especially by the first rotor, via the differential gear. In particular, the differential gear allows, for example, the outer wheel to rotate at a higher speed than the inner wheel.

[0009] The electric drive system also includes a gearbox in addition to the differential gear. This gearbox is positioned within the torque flow between the first rotor and the differential gear, specifically between the first rotor and the differential gear. This torque flow is transmitted from the first rotor to the differential gear and then, via the differential gear, into the differential gear. This means that the gearbox is located within the torque flow, downstream of the first rotor and upstream of the differential gear. The gearbox has a first input shaft, also referred to as the first gearbox input shaft, and an output shaft, also referred to as the gearbox output shaft. The gearbox output shaft is parallel to and offset from the first input shaft.This means in particular that the first input shaft is rotatable about a first input shaft axis of rotation, in particular offset from the stator, and the transmission output shaft is rotatable about an axis of rotation of the output shaft, also referred to as the output shaft axis of rotation, in particular relative to the stator, wherein the first input shaft axis of rotation and the output shaft axis of rotation are parallel to each other and spaced apart from each other.

[0010] The transmission also has two gears arranged coaxially to the first input shaft and preferably also coaxially to each other, namely a first gear and a second gear. The transmission also has two gears arranged coaxially to the output shaft and thus also coaxially to each other, namely a third gear and a fourth gear. For example, the third gear meshes with the first gear. Alternatively or additionally, the fourth gear meshes with the second gear. Thus, for example, the third gear can be driven by the first gear. Alternatively or additionally, the fourth gear can be driven by the second gear. For example, the first gear and / or the second gear can be driven by the first input shaft. For this purpose, for example, the first gear and / or the second gear can be connected to the first input shaft in a torque-transmitting manner, in particular in a rotationally fixed manner.Furthermore, it is conceivable that the first gear and / or the second gear are arranged on the first input shaft. It is also conceivable that the output shaft can be driven by the third gear and / or the fourth gear. The third gear and / or the fourth gear can be arranged on the output shaft. In particular, it is conceivable that the third gear and / or the fourth gear can be connected to the output shaft in a rotationally fixed manner.

[0011] The electric drive system also comprises a one-piece drive housing in which the first electric machine and the gearbox are each at least partially, and in particular at least predominantly, and thus to more than half or completely, enclosed. It is specifically provided that the first rotor, the differential gear, the first input shaft, the output shaft, and the gears are rotatable relative to the drive housing. In particular, it may be provided that the first stator is non-rotatably connected to the drive housing, and thus fixed to the drive housing in a rotationally fixed manner.The characteristic that the drive housing is formed in one piece can be understood to mean, in particular, that the drive housing is not composed and constructed from separately formed and connected housing parts, but rather that the drive housing is preferably formed from a single piece, and thus as a monoblock. In other words, the drive housing is an integral body, that is, an integral and therefore manufactured or formed body in one piece. It is particularly conceivable that the drive housing is manufactured by casting and / or forming.

[0012] The electric drive system also includes an axle housing, which is provided in addition to the drive housing and preferably designed separately from it. This axle housing can be designed as a single piece or in multiple parts. The feature that the axle housing can be designed in multiple parts means, in particular, that the axle housing can be constructed or assembled from several separately designed and interconnected housing elements. The differential gear is housed in the axle housing, in particular such that the differential gear and the differential gear's axis of rotation are rotatable relative to the axle housing. Specifically, it is conceivable that the first rotor, the differential gear, the first input shaft, the output shaft, and the gears are rotatable relative to the axle housing.

[0013] The axis of rotation of the first rotor, i.e., the machine axis of rotation, the axis of rotation of the output shaft, i.e., the output shaft axis of rotation, and the axis of rotation of the differential gear, i.e., the differential gear axis of rotation, are arranged parallel and offset from one another. The machine axis of rotation, the output shaft axis of rotation, and the differential gear axis of rotation are collectively referred to as the first axes of rotation. Thus, it is intended that the first axes of rotation run parallel to each other and are spaced apart.

[0014] The drive housing and the axle housing are directly connected to each other by means of a first flange connection. This means, in particular, that the drive housing and the axle housing are not connected to each other via a separate housing element formed separately from both the drive housing and the axle housing, but rather that the drive housing and the axle housing are directly connected to each other by means of the first flange connection. A first flange plane of the first flange connection is arranged parallel to the axis of rotation of the differential gear. For example, the drive housing has at least one first flange, and the drive housing has, for example, at least one second flange.The first flange and the second flange are also referred to as connecting flanges and are flanges of the first flange connection, wherein the drive housing and the axle housing are directly connected to each other via the first flange and the second flange, for example, such that the first flange and the second flange are connected to each other, particularly directly. It can be provided, in particular, that the first flange and the second flange are bolted together, particularly directly, and thereby connected to each other. In particular, the first flange and the second flange are connected to each other in the first flange plane, particularly such that the first flange and the second flange are supported against each other in the first flange plane, particularly directly.Thus, for example, the first flange plane is a first separation plane in which the first flange and the second flange are supported against each other, in particular directly, and / or connected to each other.

[0015] In order to achieve a particularly compact design and to keep the number of sealing surfaces particularly low and / or to integrate advantageous planar sealing surfaces, it is provided according to the invention that the first rotor and the, in particular all, gears of the transmission are arranged completely within the drive housing.

[0016] The term "within the drive housing" means that the element does not protrude through an outer enclosing surface of the drive housing, the outer enclosing surface being formed by an outer surface of a wall of the drive housing and - where the drive housing has openings or flanges - by flange surfaces or opening surfaces.

[0017] The drive housing and the axle housing are collectively referred to as the housing. Furthermore, according to the invention, a first cover and a second cover are provided, preferably being designed separately from each other. It is also preferably the case that the first cover and the second cover are designed separately from the housing. The first cover and the drive housing are directly connected to each other by means of a second flange connection, whereby the preceding and following descriptions of the first flange connection can also be applied to the second flange connection and vice versa.The second cover and the drive housing are directly connected to each other by means of a third flange connection, whereby the preceding and following descriptions of the first and second flange connections can also be applied to the third flange connection and vice versa. Thus, for example, the cover has a third flange, and the drive housing has at least a fourth flange, wherein the third and fourth flanges are flanges of the second flange connection. The third and fourth flanges are directly connected to each other, in particular by being bolted together, for example.The second cover, for example, has a fifth flange, and the drive housing, for example, has at least a sixth flange, wherein the fifth and sixth flanges are flanges of the third flange connection. The fifth and sixth flanges are, for example, directly connected to each other, in particular by being bolted directly to each other and thereby connected.

[0018] Furthermore, according to the invention, a second flange plane of the second flange connection and a third flange plane of a third flange connection are arranged perpendicular to the axis of rotation of the differential gear, i.e., to the differential gear's axis of rotation. As already explained for the first flange connection, it is conceivable that the third and fourth flanges in the second flange plane are connected to each other, particularly directly, and / or supported against each other. Accordingly, it is conceivable that the fifth and sixth flanges of the third flange plane are connected to each other, particularly directly, and / or supported against each other. For example, the second and third flange planes run parallel to each other, with the second and third flange planes being spaced apart from each other. Furthermore, for example, the second and third flange planes run perpendicular to the first flange plane.The invention allows for a particularly low number of parts and thus a significant reduction in the cost, weight, and installation space required for the electric drive system. Furthermore, the number of sealing surfaces can be minimized, thereby keeping sealing effort and costs advantageously low. In particular, at least one of the housings can be designed as a slide-in housing, especially such that, for example, the first electric motor and / or the gearbox can be inserted into the drive housing, particularly through a respective through-opening, wherein, for example, a first through-opening is closed by the first cover and a second through-opening is closed by the second cover.Alternatively or additionally, the differential gear can, for example, be inserted into the axle housing, also known as the axle bridge, particularly via a third through-opening, which is closed, for example, by connecting the housings together. Thus, it is conceivable that the first and second through-openings are through-openings of the drive housing, with, for example, the through-openings of the drive housing being arranged on opposite sides of the drive housing, particularly when viewed along the machine's axis of rotation.

[0019] In particular, the invention enables a simple and space-saving combination of the first electric machine and a gear set in the form of the gearbox, including the differential gear, which is designed, for example, as an axle drive or also referred to as an axle drive. It is conceivable that the drive housing and the associated covers, as well as the first electric machine and the gearbox, form a single unit, a single assembly, or a composite, whereby the unit or composite can be easily connected, in particular bolted, to the axle bridge, i.e., to the axle housing. Furthermore, it is conceivable to flange on the first electric machine as a so-called independent solution.

[0020] In order to provide a particularly advantageous drive system for the motor vehicle in a space-saving manner, the invention provides that the electric drive system includes a second electric machine with a second rotor arranged within the drive housing, from which the differential gear can be driven via the transmission. In particular, the rotor is rotatable about an axis of rotation of the second rotor, also referred to as the second machine axis of rotation, relative to the drive housing. For example, the second electric machine comprises a second stator by means of which the second rotor can be driven and is thereby rotatable about the second machine axis of rotation relative to the second stator and relative to the drive housing. It is particularly conceivable that the machine axes of rotation run parallel to each other and are spaced apart from one another.

[0021] In order to achieve a particularly compact design of the electric drive system, one embodiment of the invention provides that the transmission has a countershaft arranged parallel to and offset from the first input shaft and parallel to and offset from the output shaft. This means, in particular, that the countershaft is rotatable about an axis of rotation of the countershaft, also referred to as the countershaft axis of rotation, relative to the housings, wherein the countershaft axis of rotation runs parallel to the first input shaft axis of rotation and parallel to the output shaft axis of rotation, and is spaced apart from the first input shaft axis of rotation and from the output shaft axis of rotation.A switchable spur gear pair is provided, comprising the first gear and a first countershaft gear arranged coaxially with the countershaft, wherein the countershaft gear is provided in addition to the gears of the transmission, i.e., in addition to the first, second, third, and fourth gears. Furthermore, a second switchable spur gear pair is provided, comprising the second gear and a second countershaft gear arranged coaxially with the countershaft, wherein the second countershaft gear is provided in addition to the first countershaft gear and in addition to the first, second, third, and fourth gears of the transmission. It is specifically provided that the first gear is in mesh with the first countershaft gear, and preferably the second gear is in mesh with the second countershaft gear.The first gear and the first countershaft gear are collectively referred to as the first spur gear pair, and the second gear and the second countershaft gear are collectively referred to as the second spur gear pair. The characteristic that the respective spur gear pair is switchable can be understood, in particular, as follows: At least or exactly one of the respective spur gear pairs is, for example, designed as a loose gear rotatably mounted on the first input shaft or on the countershaft. It is particularly conceivable that the first gear and the second gear are designed as loose gears rotatably mounted on the first input shaft. Furthermore, it is conceivable that the countershaft gears are permanently, and in particular permanently, fixedly connected to the countershaft.

[0022] The characteristic that two elements, such as the respective countershaft gear and the countershaft, are connected to each other in a rotationally fixed manner means that the elements are arranged coaxially to each other and, when connected to each other in a rotationally fixed manner, rotate at the same angular velocity, especially when the elements are driven.

[0023] The characteristic that two elements, such as the respective countershaft gear and the countershaft, are permanently and rotationally fixed to one another, means in particular that no switching element is provided which can be switched between a connected state that fixes the elements to one another and a release state in which the connecting element allows relative rotation between the elements, especially around the common axis of rotation. Rather, the elements are permanently, that is, always, rotationally fixed to one another. In other words, a rotationally fixed connection between two elements means that these two elements are arranged coaxially to each other and are connected in such a way that they rotate, or are rotated, at the same angular velocity, especially when they are driven.

[0024] With regard to the respective switchable spur gear pair, the feature that the respective spur gear pair is switchable means in particular that a switching device is provided which is preferably switchable between at least one first coupling state, at least one second coupling state and, for example, at least one decoupling state.In the first coupling state, one of the loose gears is non-rotatably connected to the first input shaft or to the countershaft by means of the switching device, in particular while the other loose gear is rotatable relative to the first input shaft or relative to the countershaft, in particular about the first input shaft axis of rotation or about the countershaft axis of rotation, thus allowing a relative rotation between the other loose gear and the first input shaft or countershaft, in particular about the first input shaft axis of rotation or about the countershaft axis of rotation.In the second coupling state, the other loose gear is non-rotatably connected to the first input shaft or the countershaft by means of the switching device, in particular while one loose gear is rotatable about the first input shaft's axis of rotation or the countershaft's axis of rotation relative to the first input shaft or the countershaft. The decoupling state can, for example, be omitted.

[0025] In the preferably, but optionally, provided decoupling state of the switching device, both the one loose gear and the other loose gear can be rotated, in particular about the first input shaft axis of rotation and the countershaft axis of rotation, respectively, relative to the first input shaft and the countershaft. Thus, it is preferably provided that the switching device, in the decoupling state, allows both a relative rotation, in particular about the first input shaft axis of rotation and the countershaft axis of rotation, between one loose gear and the first input shaft and the countershaft, respectively, and a relative rotation, in particular about the first input shaft axis of rotation and the countershaft axis of rotation, between the other loose gear and the first input shaft and the countershaft, respectively.This allows, for example, advantageous switching capabilities and thus advantageous drivability of the drive system to be achieved in a particularly space-saving manner.

[0026] Another embodiment is characterized in that the axis of rotation of the countershaft, i.e., the countershaft axis of rotation, the axis of rotation of the output shaft, i.e., the output shaft axis of rotation, and the axis of rotation of the differential gear, i.e., the differential gear axis of rotation, are all arranged or run, at least substantially, in a first common plane. This allows the installation space required for the electric drive system to be kept to a particularly small level.

[0027] To achieve a particularly compact and thus space-saving design of the electric drive system, a further embodiment of the invention provides that the transmission comprises a first sub-transmission, comprising the first spur gear pair and the second spur gear pair, and a second sub-transmission. The second sub-transmission is arranged in the torque flow and is downstream of the first sub-transmission. This means that the second sub-transmission is arranged downstream of the first sub-transmission and, in particular, upstream of the differential gear, especially the differential wheel, in the torque flow. Thus, for example, the differential wheel, and therefore the differential gear, can be driven by the first sub-transmission via the second sub-transmission, wherein, for example, the second sub-transmission can be driven by the first rotor via the first sub-transmission, and wherein the first sub-transmission can be driven by the first rotor.The second sub-transmission comprises the output shaft and a planetary gear set arranged coaxially to the output shaft, which is provided in addition to the gears and the countershaft gears. It is particularly preferred that the countershaft gears are also arranged in the drive housing. Furthermore, it is preferably that the first sub-transmission and the second sub-transmission are arranged in the drive housing. Most preferably, the planetary gear set is also arranged in the drive housing.

[0028] To minimize the installation space required for the electric drive system, a further embodiment of the invention provides that the planetary gear set is arranged axially overlapping the first rotor. This means, in particular, that the planetary gear set is at least partially overlapped or covered by a longitudinal region of the first rotor extending in the axial direction of the first rotor, i.e., at least a longitudinal region of the planetary gear set extending radially outwards, particularly in the axial direction of the planetary gear set.Furthermore, this allows for a high degree of ease of assembly, in particular by the fact that, for example, the first electric machine and the planetary gear set are mounted from a first side of the drive housing and the rest of the gearbox from a second side of the drive housing opposite the first side, in particular by moving into the drive housing and thus arranging them in the drive housing.

[0029] To minimize the installation space required for the electric drive system, a further embodiment of the invention provides that the first partial gearbox comprises a second input shaft arranged coaxially with the second rotor. In particular, the second input shaft is rotatable about an axis of rotation of the second input shaft, also referred to as the second input shaft axis of rotation, relative to the drive housing. Specifically, the first input shaft can be driven by the first rotor and is thereby rotatable about the first input shaft axis of rotation relative to the drive housing. For example, the first rotor is, in particular, permanently and rotationally fixed to the first input shaft, or can be connected to it. Alternatively or additionally, for example, the second rotor is, in particular, permanently and rotationally fixed to the second input shaft, or can be connected to it.In particular, the second input shaft can be driven by the second rotor and thereby rotated into the second input shaft axis of rotation relative to the drive housing.

[0030] Preferably, a third switchable spur gear pair is provided, comprising a fifth gear arranged coaxially to the second input shaft and the first countershaft gear. More preferably, a fourth switchable spur gear pair is provided, comprising a sixth gear arranged coaxially to the second input shaft and the second countershaft gear. The preceding and following descriptions for the first spur gear pair or second spur gear pair can readily be applied to the third spur gear pair and the fourth spur gear pair. In particular, the fifth gear meshes with the first countershaft gear. Alternatively or additionally, the sixth gear meshes with the second countershaft gear. The preceding and following descriptions for the first gear and the second gear can, in particular, be applied to the fifth gear and the sixth gear, and vice versa.Preferably, the fifth gear and the sixth gear, as well as the second input shaft, are also arranged in the drive housing.

[0031] In order to keep the installation space requirement particularly low, a further embodiment of the invention provides that the axis of rotation of the first rotor, i.e. the first machine axis of rotation, and the axis of rotation of the second rotor, i.e. the second machine axis of rotation, are arranged or run in a second common plane.

[0032] In order to achieve a particularly small building space requirement, it has proven especially advantageous if the second level is arranged or runs at least essentially perpendicular to the first level.

[0033] In a further, particularly advantageous embodiment of the invention, the electric drive system has a first oil chamber designed for cooling and lubricating the first rotor. Furthermore, it is preferably provided that the electric drive system has a second oil chamber, separate from the first, designed for cooling and lubricating the transmission and the differential. The term "each oil chamber" refers in particular to one that can be supplied with oil acting as a lubricant and / or coolant, in particular such that the oil can be introduced into the respective oil chamber, and in particular such that an oil mist and / or an oil sump forms in the respective oil chamber.Components located within the respective oil chamber, for example, splash in the oil sump and / or are at least partially surrounded by the oil mist, thus being supplied with the oil absorbed in the respective oil chamber and subsequently lubricated and / or cooled by the oil. This allows for a particularly space-saving and precisely tailored cooling and lubrication system.

[0034] In order to achieve particularly advantageous lubrication and cooling in a space-saving and cost-effective manner, a further embodiment of the invention provides that the electric drive system includes a mechanical oil pump, driven by or via the gearbox, in particular mechanically, for supplying the second oil chamber with oil, wherein the mechanical oil pump is arranged on a side of the first cover facing away from the gearbox. This means that the oil can be pumped by means of the oil pump in such a way that the oil can be supplied to the second oil chamber, in particular introduced into the first oil chamber.

[0035] It has proven particularly advantageous if the mechanical oil pump comprises a pump housing and an impeller arranged within the pump housing, which is advantageously arranged coaxially to the output shaft and particularly advantageously connected to a shaft of the second sub-transmission. Thus, for example, the impeller can be mechanically driven by the output shaft or by another shaft of the second sub-transmission arranged coaxially to it, and is therefore rotatable about the output shaft's axis of rotation relative to the housings. Preferably, the pump housing is designed separately from the covers and separately from the housings and is connected at least indirectly, and in particular directly, to one of the housings.

[0036] To minimize the installation space required for the electric drive system, a further embodiment of the invention provides for a first oil cooler to be arranged inside the pump housing for cooling the oil. This allows for particularly small external dimensions of the electric drive system, while simultaneously providing advantageous oil cooling.

[0037] Finally, it has proven particularly advantageous for the electric drive system to include a cooling module for supplying oil to the first oil chamber. This cooling module comprises an electric pump by which the oil can be supplied to, and thus pumped into, the first oil chamber. The electric pump is electrically driven. This means, in particular, that the electric pump has a second impeller and an electric motor by which the second impeller is driven, thereby pumping the oil to, and especially into, the first oil chamber. Furthermore, the cooling module preferably includes a second oil cooler by which the oil, especially that pumped by the electric pump, can be cooled. The cooling module is arranged on the side of the axle housing facing away from the transmission, thus minimizing the required installation space.

[0038] Also disclosed is a motor vehicle, preferably designed as a motor car, in particular as a commercial vehicle, which has an electric drive system according to the invention and can therefore be driven electrically, in particular purely, by means of the electric drive system. Advantages and advantageous embodiments of the electric drive system are to be regarded as advantages and advantageous embodiments of the motor vehicle and vice versa.

[0039] Preferably, it is provided that at least one or more oil channels through which the oil can flow run are located within the first cover and within the drive housing, in order to guide and, in particular, distribute the oil supplied by means of the mechanical oil pump, especially also and most particularly into the second oil chamber.

[0040] It is also conceivable that at least one or more conduit elements, for example designed as oil hoses and through which the oil pumped by the electric oil pump can flow, lead from the cooling module to at least the first rotor, and in particular to the rotors, in order to supply at least the first rotor, and in particular the rotors, with the oil pumped by the electric oil pump. In particular, it is conceivable that the conduit element(s) lead from the cooling module to the starter winding heads of the respective stator, in order to supply the starter winding heads with the oil pumped by the electric oil pump. The respective conduit element is thus used to supply the oil to the respective rotor and to the stator winding heads of the respective stator.Furthermore, it is conceivable that at least one or more additional conduit elements are provided, which are designed, for example, as oil hoses and used as return lines to, for example, drain the oil from the rotors and the stator winding heads, in particular back to the cooling module. It is also possible that conduits, designed as hoses or referred to as hoses, in particular water hoses, or at least one conduit, in particular, lead from the cooling module to the stator or stators, wherein the conduits are, for example, permeable to a coolant, in particular water, and preferably liquid, through which the respective stator can be supplied with the coolant and thereby cooled. This allows for a particularly advantageous stator cooling system.

[0041] The first oil cooler, located in the pump housing of the mechanical oil pump, is a separate oil cooler for the mechanical oil pump. This allows the oil pumped by the mechanical pump, and especially the oil pumped towards the second oil chamber, to be cooled by the first oil cooler. In other words, the oil pumped by the mechanical pump can flow through the first oil cooler, particularly on its way from the mechanical oil pump to the second oil chamber, so that the oil pumped by the mechanical oil pump is cooled by the first oil cooler on its way from the mechanical oil pump to the second oil chamber.

[0042] Within the scope of this disclosure, elements arranged entirely within the drive housing are understood to mean that these elements do not partially project from the drive housing through flange planes defined by the flange halves of the drive housing, but are arranged entirely within a space of the drive housing bounded by the housing walls and flange planes. Preferably, the third switchable spur gear pair and the fourth switchable spur gear pair, as well as the planetary gear set, are also arranged entirely within the drive housing. In particular, the flange halves mentioned above are to be understood as the flanges mentioned previously, such that the respective flange is attached to or forms part of the respective flange halves.

[0043] Further advantages, features, and details of the invention will become apparent from the following description of a preferred embodiment with reference to the drawing. The features and combinations of features mentioned above in the description, as well as the features and combinations of features mentioned below in the figure description and / or shown in the figures alone, can be used not only in the combinations specified, but also in other combinations or individually, without departing from the scope of the invention, as defined in claim 1.

[0044] The drawing shows in: Fig. 1 a schematic representation of an electric drive system for a motor vehicle; Fig. 2 a schematic side view of the drive system; and Fig. 3 another schematic representation of the electric drive system.

[0045] In the figures, identical or functionally equivalent elements are provided with the same reference numerals.

[0046] Fig. 1 Figure 1 shows a schematic representation of an electric drive system 10 for a motor vehicle. This means that the motor vehicle, preferably designed as a car, in particular as a commercial vehicle, has the electric drive system 10 in its fully manufactured state and can be driven, in particular purely electrically, by means of the electric drive system 10. Fig. 1 It is evident that the drive system 10 is part of an axle 12 of the motor vehicle, also referred to as a vehicle axle. The axle 12 has at least or exactly two wheels 14, also referred to as vehicle wheels, which are arranged on opposite sides of the motor vehicle in the transverse direction. The transverse direction of the vehicle, which is also referred to as the y-direction, is in Fig. 1 illustrated by a double arrow 16. The wheels 14, and thus the motor vehicle 1, can be driven by means of the electric drive system 10, in particular purely electrically, and thereby, as for example in Fig. 1 as illustrated by arrow 18, rotatable, in particular relative to a motor vehicle structure not shown in detail in the figures.

[0047] The electric drive system 10 comprises a first electric machine 20, which has a first stator 22 and a first rotor 24. Furthermore, in the embodiment shown in the figures, the drive system 10 comprises a second electric machine 26 with a second stator 28 and a second rotor 30. For the sake of clarity, and because the electric machines 20 and 26 are very similar or even identical with regard to their functions, particularly concerning the propulsion of the motor vehicle, the following are shown in the figures: Fig. 1 The electric machines 20 and 26 are not shown separately, but are shown congruently. The first rotor 24 can be driven by means of the first stator 22 and is rotatable about a first machine axis of rotation 32 relative to a housing 34 of the drive system 10. The second rotor 30 can be driven by means of the second stator 28 and is rotatable about a second machine axis of rotation 36 relative to the housing 34. For the sake of clarity and simplicity, in Fig. 1 The machine axes of rotation 32 and 36 are shown to be congruent, that is, they appear to coincide. In reality, however, the electric machines 20 and 26 are separate components, so that the electric machine 26 is provided in addition to the electric machine 20, and vice versa. The rotors 24 and 30 are arranged parallel and offset from each other, so that the machine axes of rotation 32 and 36 do not actually coincide, but are spaced apart and run parallel to each other. The respective machine axis of rotation 32 or 36 is also referred to as the respective axis of rotation of the respective rotor 24 or 30. The respective electric machine 20 or 26 can provide torque via its respective rotor 24 or 30 for driving the wheels 14, and thus the motor vehicle, particularly in a purely electric manner.

[0048] The drive system 10 further comprises a differential gear 38, also referred to simply as the differential, which is associated with the axle 12 and the two electric machines 20 and 26. In the embodiment shown in the figures, the differential gear 38 is designed as a bevel gear differential. The differential gear 38 is part of the axle 12. The differential gear 38 has a differential gear 40, for example, designed as an input spur gear, through which the torques supplied by the electric machines 20, 26 via their rotors 24, 30 can be introduced into the differential gear 38, thereby driving the differential gear 38.In other words, the electric machines 20 and 26 can drive the differential gear 40 and thus the differential transmission 38 via their rotors 24 and 30, in particular by means of the aforementioned torques, thereby allowing the differential gear 40 and the differential transmission 38 as a whole to rotate about a differential gear axis 42 relative to the housing assembly 34. The differential gear axis 42 is also referred to as the axis of rotation of the differential gear 40.

[0049] Advantageously, the differential gear axis 42 is arranged parallel to and spaced apart from the machine axes of rotation 32 and 36. It is evident that the torques provided by the electric machines 20 and 26 via their rotors 24 and 30 can be transmitted to the wheels 14 via the differential gear 38 and, in particular, distributed or divided, so that the wheels 14 can be driven by the differential gear 38 and, via the differential gear 38, by the rotors 24 and 30. The differential gear 38 has a differential carrier 41, which is permanently and rotationally fixed to the differential gear 40 and is thus rotatable with the differential gear 40 about the differential gear axis 42 relative to the housing 34. The differential gear 38 has output gears 44 and 46 designed as bevel gears.A first output gear 44 of the output gears 44, 46 is, in particular permanently, rotationally fixed to a first side shaft 48, so that, with respect to the plane of the image, . Fig. 1 The left of the wheels 14 can be driven via the side shaft 48 by the first output gear 44. A second output gear 46 of the output gears 44, 46 is, in particular permanently, rotationally fixed to a second side shaft 50, so that, with respect to the plane of the image, Fig. 1 The right-hand side of the gears 14 can be driven via the side shaft 50 by the second output gear 46. The output gears 44 and 46 mesh with, for example, bevel gears 52 and 54 of the differential 38. The differential gears 52 and 54 are rotatably mounted on the differential housing 41 and can rotate with the differential housing 41 and the differential gear 40 about the differential gear axis of rotation 42 relative to the housing 34. Thus, the output gears 44 and 46, and with them the side shafts 48 and 50, can be driven by the differential gears 52 and 54, and via these by the differential housing 41 and differential gear 40.

[0050] In the embodiment shown in the figures, the differential gear 38 advantageously has a differential lock 56, by means of which the differential gear 38 can be locked, in particular completely, so that the compensating gears 52 and 54 and the output gears 44 and 46 rotate together with the differential basket 41 and the differential gear 40 as a block.

[0051] The electric drive system 10 further comprises a gearbox 58 in addition to the differential gearbox 38. This gearbox 58 is arranged in the torque flow between the rotors 24 and 30 and the differential gearbox 40 with respect to the torque flow emanating from the respective electric machine 20 or 26. The torques from the respective rotors 24 and 30 can be transmitted to the differential gearbox 38 and, in turn, to the differential gear 40, and introduced into the differential gearbox 38 via the differential gear 40. This means that the gearbox 58 is arranged in the torque flow downstream of the rotors 24 and 30 and upstream of the differential gear 40.

[0052] The gearbox 58 has a first input shaft 60, which in this case can be driven by the first rotor 24 and is therefore rotatable about a first input shaft axis of rotation 62 relative to the housing assembly 34. In the case of the Fig. 1 In the illustrated embodiment, the first input shaft rotation axis 62 coincides with the first machine rotation axis 32, since the first input shaft 60 is arranged coaxially with the first rotor 24. It is particularly intended that the first input shaft 60 is permanently and rotationally fixed to the first rotor 24.

[0053] Since at the in Fig. 1 In the illustrated embodiment, where the second electric machine 26 is also provided, the gearbox 58 also has a second input shaft 64, which is rotatable about a second input shaft axis of rotation 66 relative to the housing assembly 34. Due to the simplified representation of Fig. 1 The input shaft rotation axes 62 and 66 are shown to coincide. In fact, however, and in the Fig. 2 As can be seen in the side view shown, the input shaft axes of rotation 62 and 66 are parallel to each other and spaced apart. Preferably, the input shaft axis of rotation 66 coincides with the second machine axis of rotation 36, and preferably the second input shaft 64 is arranged coaxially with the second rotor 30. In particular, the second input shaft 64 is permanently and non-rotatably connected to the second rotor 30. The second input shaft 64 is driven by the second rotor 30 and is therefore rotatable about the second input shaft axis of rotation 66 relative to the housing assembly 34.

[0054] The gearbox 58 also has an output shaft 68 arranged parallel and offset from the input shafts 60 and 64, which is rotatable about an output shaft axis 70 relative to the housing assembly 34. Thus, the output shaft axis 70 runs parallel to the machine axes of rotation 32 and 36 and parallel to the input shaft axes of rotation 62 and 66, with the output shaft axis 70 being spaced apart from the machine axes of rotation 32 and 36 and from the input shaft axes of rotation 62 and 66.

[0055] The transmission 58 comprises two gears 72 and 74 arranged coaxially with the first input shaft 60, gear 72 also being referred to as the first gear and gear 74 as the second gear. The transmission 58 also includes gears 76 and 78 arranged coaxially with the output shaft 68, gear 76 also being referred to as the third gear and gear 78 as the fourth gear. In the Fig. 1 In the illustrated embodiment, the transmission 58 also has a fifth gear 80 and a sixth gear 82. The gears 80 and 82 are arranged coaxially with the second input shaft 64.

[0056] The electric drive system 10 further comprises a one-piece drive housing 84, which is also referred to as an axle-mounted housing. The electric motors 20 and 26 and the gearbox 58 are each at least partially, and in particular at least predominantly, enclosed in the drive housing 84, and thus each at least more than halfway or completely.

[0057] Furthermore, the drive system 10 comprises an axle housing 86, also referred to as an axle bridge, which is preferably designed separately from the drive housing 84 and connected to the drive housing 84. The differential gear 38 is, in particular completely, housed in the axle housing 86. The first machine axis of rotation 32, also referred to as the axis of rotation of the first rotor 24, the second machine axis of rotation 36, also referred to as the axis of rotation of the second rotor 30, the output shaft axis of rotation 70, also referred to as the axis of rotation of the output shaft 68, and the differential gear axis of rotation 42, also referred to as the axis of rotation of the differential gear 40, are arranged parallel and offset from one another; thus, they run parallel to each other and are spaced apart from one another.

[0058] Furthermore, it is provided that the drive housing 84 and the axle housing 86 are directly connected to each other by means of a first flange connection 88. The first flange connection 88 comprises exactly one first flange 90 of the drive housing 84 and exactly one second flange 92 of the axle housing 86, wherein the flanges 90 and 92 are directly connected to each other, in particular directly bolted together, in a first flange plane F1 of the first flange connection 88. It can be seen that the first flange plane F1 of the first flange connection 88 runs parallel to the differential gear axis of rotation 42 and is spaced apart from the differential gear axis of rotation 42.Furthermore, it is preferably provided that the first flange plane F1 runs parallel to the machine rotation axes 32 and 36, parallel to the input shaft rotation axes 62 and 66 and parallel to the output shaft rotation axis 70 and is spaced apart from the machine rotation axes 32 and 36, from the input shaft rotation axes 62 and 66 and from the output shaft rotation axis 70.

[0059] In order to achieve a particularly compact design of the electric drive system 10, it is further provided that the first rotor 24, the second rotor 30 and, in particular, all gears 72, 74, 76, 78, 80 and 82 of the gearbox 58 are arranged completely within the drive housing 84.

[0060] The electric drive system comprises a first cover 94 and a second cover 96. The drive housing 84 and the axle housing 86 are also referred to as housings or housing parts, wherein the drive housing 84 and the axle housing 86 are components, and thus housings, of the housing assembly 34. The covers 94 and 96, which are also components of the housing assembly 34, are designed separately from each other and separately from the housings, that is, separately from the drive housing 84 and separately from the axle housing 86.It can be seen that the first cover 94 is arranged on a first side S1 of the drive housing 84, and the second cover 96 is arranged on a second side S2 of the drive housing 84, with sides S1 and S2 being opposite each other or pointing away from each other in the axial direction of the gearbox 58 and thus along the respective input shaft rotation axes 62 and 66 and along the output shaft rotation axis 70. The cover 94 completely closes a first through-opening of the drive housing 84 located on side S1. Additionally, the second cover 96 completely closes a second through-opening of the drive housing 84 located on the second side S2.

[0061] The first cover 94 and the drive housing 84 are directly connected to each other by means of a second flange connection 98. The second flange connection 98 comprises exactly a third flange 100 of the cover 94 and exactly a fourth flange 102 of the drive housing 84, wherein the flanges 100 and 102 are directly connected to each other, in particular directly bolted together, in a second flange plane F2 of the second flange connection 98. The second cover 96 and the drive housing 84 are directly connected to each other by means of a third flange connection 104. The third flange connection 104 comprises exactly a fifth flange 106 of the second cover 96 and exactly a sixth flange 108 of the drive housing 84, wherein the flanges 106 and 108 are directly connected to each other, in particular directly bolted together, in a third flange plane F3 of the third flange connection 104.

[0062] Out of Fig. 1 It can be seen that the second flange plane F2 of the second flange connection 98 and the third flange plane F3 of the third flange connection 104 run perpendicular to the differential wheel rotation axis 42.

[0063] Furthermore, the second flange plane F2 of the second flange connection 98 and the third flange plane F3 of the third flange connection 104 are arranged parallel to each other and spaced apart from each other.

[0064] The transmission 58 has a countershaft 110, which is rotatable about a countershaft axis 112 relative to the housing assembly 34. It can be seen that the countershaft axis 112 runs parallel to the machine axes 32 and 63, parallel to the input shaft axes 62 and 66, parallel to the output shaft axis 70, and parallel to the differential gear axis 42, and is spaced apart from the machine axes 32 and 36, the input shaft axes 62 and 66, the output shaft axis 70, and the differential gear axis 42. A first switchable spur gear pair 117 is provided, comprising the first gear 72 and a first countershaft gear 114 arranged coaxially with the countershaft 110.

[0065] At the in Fig. 1 In the illustrated embodiment, the first countershaft gear 114 is permanently and rotationally fixed to the countershaft 110. Furthermore, the countershaft gear 114 meshes with the first gear 72. In other words, the gear 72 is in engagement with the first countershaft gear 114.

[0066] Furthermore, a second switchable spur gear pair 118 is provided, comprising the second gear 74 and a second countershaft gear 116. The second countershaft gear 116 is arranged coaxially with the countershaft 110 and thus coaxially with the first countershaft gear 114. In the Fig. 1 In the illustrated embodiment, the second countershaft gear 116 is permanently and rotationally fixed to the countershaft 110. Furthermore, the second gear 74 is in mesh with the second countershaft gear 116.

[0067] At the in Fig. 1 In the illustrated embodiment, a third switchable spur gear pair 120 is provided, comprising the fifth gear 80 and the first intermediate gear 114. The fifth gear 80 is in mesh with the intermediate gear 114, preferably not in mesh with the first gear 72. Furthermore, a fourth switchable spur gear pair 122 is provided, comprising the sixth gear 82 and the second intermediate gear 116. The sixth gear 82 is in mesh with the second intermediate gear 116, preferably not in mesh with the second gear 74.

[0068] At the in Fig. 1 In the illustrated embodiment, gears 72, 74, 80, and 82 are designed as switchable loose gears. Alternatively, as is known to those skilled in the art, the intermediate gears 114 and 116 could also be designed as switchable loose gears. It is known to those skilled in the art that in a switchable spur gear pair where two gears mesh with each other, at least one of the two meshing gears must be designed as a switchable loose gear, with the other of these two gears normally being designed as a fixed gear.

[0069] At the in Fig. 1 In the illustrated embodiment, the gears 72 and 74 are arranged coaxially and rotatably on the first input shaft 60, and the gears 80 and 82 are arranged coaxially and rotatably on the second input shaft 64.

[0070] The gears 72 and 74, designed as loose gears, are associated with a first switching device 124, which is switchable between at least one first coupling state, at least one second coupling state, and at least one first decoupling state. In the first coupling state, the first gear 72 is rotationally fixed to the input shaft 60 by means of the switching device 124, while the second gear 74 is rotatable about the input shaft's axis of rotation 62 relative to the input shaft 60. In the second coupling state, the gear 74 is rotationally fixed to the input shaft 60 by means of the switching device 124, while the gear 72 is rotatable about the input shaft's axis of rotation 62 relative to the input shaft 60. In the first decoupling state, both gears 72 and 74 are rotatable about the input shaft's axis of rotation 62 relative to the input shaft 60.The first switching device 124 is thus designed in the exemplary embodiment as a combined switching device for both gears 72 and 74. Alternatively, and in a manner also known per se, each of the two gears 72 and 74 could have its own switching device.

[0071] The gears 80 and 82, designed as loose gears, are associated with a second switching device 126, which can be switched between a third coupling state, a fourth coupling state, and a second decoupling state. In the third coupling state, the fifth gear 80 is rotationally fixed to the input shaft 64 by means of the switching device 126, while the sixth gear 82 is rotatable about the input shaft's axis of rotation 62 relative to the input shaft 64. In the fourth coupling state, the fifth gear 82 is rotationally fixed to the input shaft 64 by means of the switching device 126, while the sixth gear 80 is rotatable about the input shaft's axis of rotation 66 relative to the input shaft 64. In the second decoupling state, both gears 80 and 82 are rotatable about the input shaft's axis of rotation 66 relative to the input shaft 64.In particular, for example, the respective switching device 124, 126 comprises a respective switching sleeve which is displaceable in particular along the respective input shaft rotation axis 62, 66 relative to the respective input shaft 60, 64, in particular between respective coupling positions that effect the respective coupling states and a respective decoupling position that effect the respective decoupling state.

[0072] Furthermore, it is preferably provided that the countershaft axis of rotation 112, also referred to as the axis of rotation of the countershaft 110, the output shaft axis of rotation 70 and the differential gear axis of rotation 42 are arranged in a first common plane.

[0073] The transmission 58 has a first sub-transmission 128, which comprises at least the first switchable spur gear pair 117 and the second switchable spur gear pair 118. In the exemplary embodiment of the Fig. 1 The first sub-transmission 128 also includes the third switchable spur gear pair 120 and the fourth switchable spur gear pair 122.

[0074] It can be seen that the countershaft 110 and the countershaft gears 114 and 116 are also arranged, in particular completely, in the drive housing 84.

[0075] The gearbox 58 exhibits the following characteristics in the Fig. 1 The illustrated embodiment also includes a second sub-transmission 130, which is arranged in the torque flow and is downstream of the first sub-transmission 128 with respect to the torque flow. This means that the sub-transmissions 128 and 130 are arranged in the torque flow, with the sub-transmission 130 being located downstream of the sub-transmission 128 and upstream of the differential gear 40.

[0076] The second sub-transmission 130 comprises the output shaft 68 and, particularly advantageously, a planetary gear set 132 arranged coaxially to the output shaft 68.

[0077] The planetary gear set 132 advantageously comprises exactly one sun gear 134, which is arranged coaxially with the output shaft 68. The sun gear 134 is permanently and rotationally fixed to a sun shaft 135, or can be connected to such a sun shaft. The planetary gear set 132 also comprises exactly one ring gear 136 and exactly one planet carrier 138, also referred to as a web, wherein the ring gear 136 is a second gear element and the planet carrier 138 is a third gear element of the planetary gear set 132. The gear elements of the planetary gear set 132 are arranged coaxially with each other and, particularly when they are not rotationally fixed to the housing assembly 34, are rotatable about a planetary gear set axis of rotation 140 relative to the housing assembly 34. Furthermore, particularly when the gear elements are not rotationally fixed to each other, the gear elements are rotatable about the planetary gear set axis of rotation 140 relative to each other.Since the transmission elements are arranged coaxially to each other and coaxially to the output shaft 68, the planetary gear set rotation axis 140 coincides with the output shaft rotation axis 70.

[0078] At the in Fig. 1 In the illustrated embodiment, the planet carrier 138 is permanently and rotationally fixed to the output shaft 68. The output shaft 68 is a hollow shaft through which the sun shaft 135 passes. Advantageously, the ring gear 136 is designed as a second hollow shaft, or, in particular, is permanently and rotationally fixed to a second hollow shaft, with the sun shaft 135 also advantageously passing through the second hollow shaft.

[0079] A third switching device 142 is preferably associated with the planetary gear set 132. The planetary gear set 132 can be switched by means of the third switching device 142, so that two different gear ratios can be achieved using the planetary gear set. Two switching states can preferably be realized by means of the third switching device: firstly, a rotationally fixed connection of two elements of the planetary gear set 132, which is referred to as a locking of the planetary gear set 132; secondly, a rotationally fixed connection of one element of the planetary gear set to the housing device 34.

[0080] In the exemplary embodiment of the Fig. 1 The third switching device 142 is switchable between at least a fifth coupling state, at least a sixth coupling state, and at least a third decoupling state. In the fifth coupling state, the ring gear 136 is connected to the housing assembly 34, particularly the drive housing 84, in a rotationally fixed manner by means of the third switching device 142, in particular via the second hollow shaft, while the sun gear 134 and the planet carrier 138 are rotatable about the planet gear set axis of rotation 140 relative to each other and relative to the housing assembly 34 and relative to the ring gear 136. Thus, in the fifth coupling state, the switching device 142 is or functions as a brake or a brake switching element, since in the fifth coupling state the ring gear 136 is connected to the housing assembly 34 in a rotationally fixed manner.

[0081] In the sixth coupling state, the sun gear 134 is rotationally fixed to the ring gear 136 by means of the third switching device 142, in particular via the sun shaft 135, so that in the sixth coupling state the planetary gear set 132, i.e. the gear elements of the planetary gear set 132, are locked together by means of the switching device 142. Thus, in the sixth coupling state, the switching device 142 is or functions as a locking switching element by means of which the gear elements of the planetary gear set 132 are locked together, so that, in particular when the planetary gear set 132 is driven, especially via the sun gear 134, the gear elements rotate together and thus as a block, and therefore rotate together about the planetary gear set axis of rotation 140 relative to the housing device 134.

[0082] In the third decoupling state, however, the third switching device 142 prevents the ring gear 136 from being rotationally fixed to either the housing assembly 34 or the sun gear 134. Therefore, in this third decoupling state, the third switching device 142 allows relative rotation between the gear elements of the planetary gear set 132, particularly in pairs, about the planetary gear set axis of rotation 140. It can be seen that the planetary gear set 132 also includes planet gears 144, which are rotatably mounted on the bridge. Each planet gear 144 is in mesh with the ring gear 136 and the sun gear 134.

[0083] At the in Fig. 1 In the illustrated embodiment, the third gear 76 is connected, in particular permanently, to the sun shaft 135 in a rotationally fixed manner, or can be connected to it. Furthermore, it is provided that the fourth gear 87 is connected, in particular permanently, to the output shaft 68 in a rotationally fixed manner, or can be connected to it. The third gear 76 meshes with an output gear 146 of the transmission 58, wherein the output gear 146, which is also simply referred to as the output gear, is connected, in particular permanently, to the countershaft 110 in a rotationally fixed manner, or can be connected to it.

[0084] It is evident that the sun shaft 135 is at least partially enclosed in the drive housing 84. The gears 76 and 78, as well as the output gear 146, are also enclosed, in particular completely, in the drive housing 84. The planetary gear set 132, and thus its transmission elements, are also enclosed, in particular completely, in the drive housing 84. Furthermore, it is evident that the countershaft 110 can be driven by the respective gear 72, 74, 80, 82 via the respective countershaft gear 114, 116, wherein the respective gear 72, 74, 80, 82 can be driven, in particular via the switching device 124, 126, by the input shaft 60, 64 and thus by the rotor 24, 30.

[0085] The output gear 146 is driven by the countershaft 110, and the third gear 76 is driven by the output gear 146, with the sun gear 135 being driven by the third gear 76. Thus, the respective torque provided by the respective electric machine 20, 26 via its rotor 24, 30 can be transmitted via the gear 76 to the sun gear 135 and via this to the sun gear 134, thereby driving the sun gear 135 and thus the sun gear 134, and thus allowing it to rotate about the planetary gear set axis 140 relative to the housing 34.

[0086] The third gear 76 is thus an input gear of the second sub-gearbox 130. The respective torque provided by the respective electric machine 20, 26 can be introduced into the second sub-gearbox 130 via this input gear.

[0087] The fourth gear 78 is an output gear of the second sub-gearbox 130. Via this output gear, the respective torque provided by the respective electric machine 20, 26 can be routed out of the sub-gearbox 130 and, in particular, transferred to the differential gear 40 and thus introduced via the differential gear 40 into the differential gear 38, whereby the differential gear 40 or the differential gear 38 can be driven and thus rotatable about the differential gear axis 42 relative to the housing assembly 34.

[0088] To minimize the required installation space, the planetary gear set 132 is arranged axially overlapping at least the first rotor 24 and preferably also the second rotor 30. Furthermore, it is preferably provided that the first machine axis of rotation 32, also referred to as the axis of rotation of the first rotor 24, and the second machine axis of rotation 36, also referred to as the axis of rotation of the second rotor 30, are arranged in a common, second plane. It is preferably provided that the first plane and the second plane are perpendicular to each other. Preferably, a gear ratio, also referred to as i, is applied from the differential gear 40 to the respective side shafts 48 and 50, such that the differential gear 40 and side shafts 48 and 50 preferably rotate at the same speed, particularly when the differential lock 56 is engaged.

[0089] The first sub-gearbox 128 also includes the countershaft 110, the countershaft gears 114 and 116, and the output gear 146, which is thus also referred to as an output gear of the first sub-gearbox 128. The respective torque provided by the respective electric machine 20, 26 is therefore routed out of the first sub-gearbox 128 via the output gear 146 and transmitted to the gear 76 and from there into the second sub-gearbox 130.

[0090] In Fig. 2 The aforementioned first common level is identifiable and labelled E1. Furthermore, it is evident from Fig. 2 The second common level is recognizable and labelled E2.

[0091] Out of Fig. 3 It is evident that the electric drive system 10 has a first oil chamber 148, which is designed for cooling and lubricating the rotors 24 and 30. The electric drive system 10 also includes a second oil chamber 150, separate from the first oil chamber 148, which is designed for cooling and lubricating the gearbox 58 and the differential gear 38. This means, in particular, that the oil chambers 148 and 150 can each be supplied with a lubricant and coolant in the form of oil, specifically such that the oil can be introduced into the respective oil chamber 148, 150. Preferably, a first oil supply system is provided for the first oil chamber 148, and a second oil supply system, separate from the first oil supply system, is provided for the second oil chamber 150.

[0092] Alternatively, though not shown here, the oil supplying the respective oil chambers 148 and 150 can be routed through or via these chambers to the rotors 24 and 30, and to the gearbox 58 and the differential 38, respectively. This would supply, lubricate, and cool the rotors 24 and 30, gearbox 58, and differential 38. In this alternative configuration, both oil chambers 148 and 150 are supplied by the same oil supply system.

[0093] In the exemplary embodiment of the Fig. 3 The electric drive system 10 has a mechanical oil pump 152, which can be driven by the gearbox 58, in particular mechanically, and by means of which the second oil chamber 150 can be supplied with oil. This means that by driving the mechanical oil pump 152, the oil can be pumped or, in addition, and in particular, pumped into and / or through the second oil chamber 150. The oil pump 152 has a Fig. 3 The pump impeller 154 is shown schematically and is rotatable about a pump impeller axis 156 relative to the housing assembly 34. The pump impeller 154 is mechanically driven by the gearbox 58 and is thus rotatable about the pump impeller axis 156 relative to the housing assembly 34, thereby pumping the oil and supplying the second oil chamber 150 with the oil pumped by the pump impeller 154. This means that the oil is pumped by means of the pump impeller 154 by driving the pump impeller 154. The mechanical oil pump 152 has a pump housing 158, which can be a component of the housing assembly 34. Advantageously, the pump housing 158 is designed separately from the drive housing 84, separately from the shaft housing 86, and also separately from the covers 94 and 96. For example, the pump housing 158 is connected, in particular directly, to the drive housing 84.The pump impeller 154 is mounted in the pump housing 158, in particular in a rotatable manner.

[0094] In the embodiment shown in the figures, the pump impeller 154 is permanently and rotationally fixed to the sun shaft 135. Thus, the pump impeller 154 is arranged coaxially with the output shaft 68 or the sun shaft 135, so that the pump impeller axis of rotation 156 coincides with the output shaft axis of rotation 70 and the planetary gear set axis of rotation 140.

[0095] Furthermore, it is from Figuren 1 and 3It is evident that the mechanical oil pump 152, and thus the pump housing 158 and preferably also the impeller 154, is arranged on side S1, specifically on a side S3 of the first cover 94 facing away from the gearbox 58. Therefore, the cover 94 is preferably arranged, viewed in one direction of the impeller's axis of rotation 156, between the pump housing 158 and the drive housing 84, and preferably also between the impeller 154 and the drive housing 84. It is therefore particularly conceivable that, for example, the pump housing 158 is connected to the cover 94, especially directly, by means of a fourth flange connection and / or in a fourth flange plane, which, for example, runs perpendicular to the impeller's axis of rotation 156.Furthermore, it is preferably provided that a separate oil cooler, not shown in the figures, is arranged in the pump housing 158 of the mechanical oil pump 152, by means of which the oil conveyed by means of the pump wheel 154 and thus by means of the mechanical oil pump 152 can be cooled, in particular on its way from the pump wheel 154 or the oil pump 152 to the second oil chamber 150.

[0096] Furthermore, the electric drive system 10 includes a cooling module 160 in addition to the mechanical oil pump 152. This cooling module is arranged on a side S4 of the axle housing 86 facing away from the transmission 58, with side S4 pointing away from sides S1, S2, and S3. In particular, it is conceivable that the cooling module 160 is designed separately from the housing assembly 134 and separately from the covers 94 and 96. For example, the cooling module 160 is connected, particularly directly, to the axle housing 86. Preferably, the cooling module 160 includes an electric pump (not shown in the figures), which is also referred to as an electric oil pump. The electric pump can deliver oil to, and in particular into, the first oil chamber 148. In other words, the electric oil pump can deliver oil, thereby supplying the first oil chamber 148 with the oil delivered by the electric oil pump.In other words, the electric pump, and thus the cooling module 160, is designed to supply the first oil chamber 148 with oil. The cooling module 160 includes a second oil cooler, provided in addition to the first oil cooler, by means of which the oil pumped by the electric oil pump can be cooled, particularly on its way to the first oil chamber 148. Preferably, the first oil chamber 148 and the second oil chamber 150 are completely separated from each other in such a way that no exchange of oil can take place between the two oil chambers 148 and 150. Preferably, different types of oil are used in the two oil chambers 148 and 150. Reference symbol list

[0097] 10 Electric drive system 12 Axle 14 Wheel 16 Double arrow 18 Arrow 20 First electric machine 22 First stator 24 First rotor 26 Second electric machine 28 Second stator 30 Second rotor 32 First machine axis of rotation 34 Housing assembly 36 Second machine axis of rotation 38 Differential gear 40 Differential gear 41 Differential carrier 42 Differential gear axis of rotation 44 Output gear 46 Output gear 48 Side shaft 50 Side shaft 52 Differential gear 54 Differential gear 56 Differential lock 58 Gearbox 60 First input shaft 62 First input shaft axis of rotation 64 Second input shaft 66 Second input shaft axis of rotation 68 Output shaft 70 Output shaft axis of rotation 72 First gear 74 Second gear 76 third gear 78 fourth gear 80 fifth gear 82 sixth gear 84 drive housing 86 axle housing 88 first flange connection 90 first flange 92 second flange 94 first cover 96 second cover 98 second flange connection 100 third flange 102 fourth flange 104 third flange connection 106 fifth flange 108 sixthFlange 110 Countershaft 112 Countershaft pivot axis 114 Countershaft gear 116 Countershaft gear 117 First spur gear pair 118 Second spur gear pair 120 Third spur gear pair 122 Fourth spur gear pair 124 Shifting device 126 Shifting device 128 First sub-gearbox 130 Second sub-gearbox 132 Planetary gear set 134 Sun gear 135 Sun shaft 136 Ring gear 138 Planetary carrier 140 Planetary gear set pivot axis 142 Shifting element 144 Planetary gear 146 Output gear 148 First oil chamber 150 Second oil chamber 152 Mechanical oil pump 154 ​​Pump impeller 156 Pump impeller pivot axis 158 Pump housing 160 Cooling module E1 First level E2 Second level F1 first flange level F2 second flange level F3 third flange level S1 first side S2 second side S3 third side S4 fourth side

Claims

1. An electric drive system (10) for a motor vehicle, comprising: - a first electric machine (20) having a first rotor (24) via which torque from the first electric machine (20) can be delivered, - a differential gear (38) having a differential gear wheel (40) via which torque can be introduced into the differential gear (38), - a transmission (58) provided in addition to the differential gear, which, with respect to a torque flow originating from the first electric machine (20) via which torque from the first rotor (24) can be transmitted to the differential gear wheel (40) and introduced into the differential gear (38) via the differential gear wheel (40), is disposed in the torque flow between the first rotor (24) and the differential gear wheel (40), and comprising a first input shaft (60), an output shaft (68) disposed parallel to and axially offset from the first input shaft (60), and at least two gear wheels (72, 74), namely a first gear wheel (72) and a second gear wheel (74) disposed coaxially to the first input shaft (60), and two gear wheels (76, 78), namely a third gear wheel (76) and a fourth gear wheel (78) disposed coaxially to the output shaft (68), - a drive housing in which the first electric machine (20) and the transmission (58) are each at least partially accommodated, - an axle housing (86) in which the differential gear (38) is accommodated, wherein: ∘ a rotation axis (32) of the first rotor (24), a rotation axis (70) of the output shaft (68), and a rotation axis (42) of the differential gear wheel (40) are disposed parallel to and axially offset from one another, ∘ the drive housing (84) and the axle housing (86) are directly connected to each other by means of a first flange connection (88), ∘ a first flange plane (F1) of the first flange connection (88) is disposed parallel to the rotation axis (42) of the differential gear wheel (40), wherein: - the gear wheels (72, 74, 76, 78) of the transmission (58) are disposed entirely within the drive housing (84), - a first cover (94) and a second cover (96) are provided, - the first cover (94) and the drive housing (84) are directly connected to each other by means of a second flange connection (98), - the second cover (96) and the drive housing (84) are directly connected to each other by means of a third flange connection (104), - a second flange plane (F2) of the second flange connection (98) and the third flange plane (F3) of the third flange connection (104) are disposed perpendicular to the rotation axis (42) of the differential gear wheel (40), characterised in that: - the drive housing is configured as one piece, - the first rotor (24) is entirely disposed within the drive housing (84), and - a second electric machine (26) having a second rotor (30) disposed within the drive housing (84) is provided, from which the differential gear wheel (40) can be driven via the transmission (58).

2. The electric drive system (10) according to claim 1, characterised in that the transmission (58) comprises a layshaft (110) disposed parallel to and axially offset from the first input shaft (60) as well as parallel to and axially offset from the output shaft (68), wherein a first shiftable spur wheel pairing (117) including the first gear wheel (72) as well as a first layshaft wheel (114) disposed coaxially to the layshaft (110) is provided, and wherein a second shiftable spur wheel pairing (118) including the second gear wheel (74) as well as a second layshaft wheel (116) disposed coaxially to the layshaft is provided.

3. The electric drive system (10) according to claim 2, characterised in that a rotation (112) of the layshaft (110), the rotation axis (70) of the output shaft (68), and the rotation axis (42) of the differential gear wheel (40) are disposed in a first common plane (E1).

4. The electric drive system (10) according to claim 2 or 3, characterised in that the transmission (58) comprises a first sub-transmission (128) including the first spur wheel pairing (117) and the second spur wheel pairing (118), and a second sub-transmission (130) disposed in the torque flow and downstream from the first sub-transmission (128) with respect to the torque flow, and which includes the output shaft (68) and a planetary wheel set (132) disposed coaxially to the output shaft (68).

5. The electric drive system (10) according to claim 4, characterised in that the planetary wheel set (132) is disposed axially overlapping the first rotor (24).

6. The electric drive system (10) according to claim 4 or 5, characterised in that: - the first sub-transmission (128) includes a second input shaft (64) disposed coaxially to the second rotor (30), - a third shiftable spur wheel pairing (120) including a fifth gear wheel (80) disposed coaxially to the second input shaft (64), and including the first layshaft wheel (114) is provided, and - a fourth shiftable spur wheel pairing (122) including a sixth gear wheel (82) disposed coaxially to the second input shaft (64), and including the second layshaft wheel (116) is provided.

7. The electric drive system (10) according to claim 6, characterised in that the rotation axis (32) of the first rotor (24) and a rotation axis (36) of the second rotor (30) are disposed in a second common plane (E2).

8. The electric drive system (10) according to claim 7 and claim 3, characterised in that the second common plane (E2) is disposed perpendicular to the first common plane (E1).

9. The electric drive system (10) according to one of the preceding claims, characterised by a first oil chamber (148) configured for cooling and lubricating the first rotor (24), and a second oil chamber (150) configured separately from the first oil chamber (148) and configured for cooling and lubricating the transmission (58) and the differential gear (38).

10. The electric drive system (10) according to claim 9, characterised by a mechanical oil pump (152) driveable by the transmission (58) and disposed on a side (S3) of the first cover (94) facing away from the transmission, for supplying oil to the second oil chamber (150).

11. The electric drive system (10) according to claims 10 and 4, characterised in that the mechanical oil pump (152) comprises a pump housing (158) and a pump wheel (154), which is disposed within the pump housing (158) and disposed coaxially to the output shaft (68) and non-rotationally connected to a shaft of the planetary wheel set (132).

12. The electric drive system (10) according to claim 11, characterised in that a first oil cooler for cooling the oil is disposed within the pump housing (158).

13. The electric drive system (10) according to one of claims 9 to 12, characterised by a cooling module (160) for providing oil to the first oil chamber (148), comprising an electric pump and a second oil cooler, and which is disposed on a side (S4) of the axle housing (86) facing away from the transmission (48).