Four-speed hybrid transmission

Abstract

Hybrid transmission (18) for a motor vehicle powertrain (12) of a motor vehicle (10), comprising: a first transmission input shaft (24) for connecting the hybrid transmission (18) to an internal combustion engine (16) of the motor vehicle; a second transmission input shaft (26) for connecting the hybrid transmission (18) with a first electric drive motor (14) of the motor vehicle; an output shaft (28) for connecting the hybrid transmission (18) with an output (34); a planetary gear set (RS) which is connected to the first transmission input shaft (24) and to the output shaft (28); Spur gear pairs (ST1, ST2, ST3) arranged in several gear set planes to form gear steps; and several gearshift devices with shifting elements (A, B, C, D, E, F) for engaging gear stages, wherein a first switching element (A) is designed to lock the planetary gear set (RS); a second switching element (B) is designed to connect the second transmission input shaft (26) to the output shaft (28) by means of a second spur gear pair (ST2) of the spur gear pairs (ST1, ST2, ST3) to form the gear stages; a third switching element (C) is designed to connect the planetary gear set (RS) to the second transmission input shaft (26) in a drive-effective manner; a fourth switching element (D) is designed to connect the first transmission input shaft (24) to the second transmission input shaft (26) in a drive-effective manner; a fifth switching element (E) is designed to connect the first transmission input shaft (24) to the output shaft (28) by means of a first spur gear pair (ST1) of the spur gear pairs (ST1, ST2, ST3) to form the gear stages; and a sixth switching element (F) is designed to connect the second transmission input shaft (26) to the output shaft (28) by means of a third spur gear pair (ST3) of the spur gear pairs (ST1, ST2, ST3) to form the gear stages, wherein the output shaft (28) is designed in a reduction gear construction; the second transmission input shaft (26) is effectively connected to one of the spur gear pairs (ST1, ST2, ST3) to form gear stages; the second transmission input shaft (26) can be connected to a ring gear or a sun gear of the planetary gear set (RS); and a switching element (A, B, C, D, E, F) for inserting an electric gear stage can be combined with another switching element to form a double switching element.

Description

[0001] The present invention relates to a hybrid transmission, a motor vehicle drive train with such a hybrid transmission, a motor vehicle with such a motor vehicle drive train and a method for operating such a motor vehicle drive train.

[0002] Vehicles are increasingly being equipped with hybrid drives, i.e. with at least two different drive sources. Hybrid drives can help reduce fuel consumption and pollutant emissions. Drivetrains with an internal combustion engine and one or more electric motors as parallel hybrids or mixed hybrids have largely become established. Such hybrid drives feature an essentially parallel arrangement of the internal combustion engine and the electric drive in the power flow. This allows both a superposition of the drive torques and control with purely internal combustion engine drive or purely electric motor drive. Since the drive torques of the electric drive and the internal combustion engine can be added together depending on the control, a comparatively smaller design of the internal combustion engine and / or its temporary shutdown is possible.This allows for a significant reduction in CO2 emissions without any significant loss of performance or comfort. The possibilities and advantages of an electric drive can thus be combined with the range, performance, and cost advantages of internal combustion engines.

[0003] A disadvantage of the aforementioned hybrid drives is their generally more complex design, as both drive sources typically transmit power to a single drive shaft via a single transmission. This makes such transmissions complex and costly to produce. Reducing the complexity of a hybrid transmission's design usually results in a loss of variability.

[0004] This disadvantage can be at least partially overcome by dedicated hybrid transmissions (DHTs), in which an electric motor is integrated into the transmission to provide the full range of functions. For example, the mechanical transmission part of the transmission can be simplified, for example by eliminating the reverse gear and using at least one electric motor instead.

[0005] Dedicated hybrid transmissions can be derived from familiar transmission concepts, such as dual-clutch transmissions, torque converter planetary transmissions, continuously variable transmissions (CVTs), or automated manual transmissions. The electric motor is preferably integrated into the transmission.

[0006] From the published patent application DE 10 2013 215 114 A1, a hybrid drive of a motor vehicle is known, which has an internal combustion engine with a drive shaft, an electric machine operable as a motor and as a generator with a rotor, an automated manual transmission designed in countershaft design with an input shaft and at least one output shaft, and a superposition transmission designed in planetary design with two input elements and one output element.In this hybrid drive, the superposition gear is arranged coaxially above a free end of the output shaft, and the first input element of the superposition gear is connected in a rotationally fixed manner to a hollow shaft arranged coaxially above the output shaft. The hollow shaft is connected in a rotationally fixed manner to an idler gear of the immediately axially adjacent spur gear stage of the manual transmission via a coupling switching element for coupling the combustion engine, and in a rotationally fixed manner to the second input element or the output element of the superposition gear via a bridging switching element for bridging the superposition gear. Furthermore, the second input element of the superposition gear is permanently drive-connected to the rotor of the electric motor, and the output element of the superposition gear is connected in a rotationally fixed manner to the output shaft.

[0007] DE 10 2018 217 849 A1 discloses a transmission for a motor vehicle with a planetary gear comprising the elements sun gear, ring gear, and carrier. The ring gear of the planetary gear forms an input side of the planetary gear, with which a first electric machine can be operatively connected. The carrier of the planetary gear forms an output side of the planetary gear, with which an output can be operatively connected. The transmission further comprises a first shifting element, via which the sun gear of the planetary gear can be connected fixedly to the housing, and a second shifting element, via which the planetary gear can be brought into block rotation, wherein the sun gear of the planetary gear can be connected to one of the other elements of the planetary gear.The transmission also includes a third shifting element, via which the sun gear of the planetary gear set can be connected to a drive shaft with which a second electric machine can be operatively connected. Furthermore, a separating clutch is provided, via which an internal combustion engine can be coupled to the drive shaft with which the second electric machine can be operatively connected. The third shifting element and the separating clutch can be controlled by a common actuator such that only one of them can be engaged at a time, but not both at the same time. However, the third shifting element and the separating clutch can both be disengaged simultaneously.

[0008] Furthermore, DE 10 2013 221 461 A1 discloses a hybrid drive of a motor vehicle comprising an internal combustion engine with a drive shaft, an electric motor operable as a motor and as a generator with a rotor, an automated manual transmission designed as a countershaft with an input shaft and at least one output shaft, and a planetary superposition gear with two input elements and one output element. The input shaft is connected to the drive shaft via a controllable separating clutch or directly and can be brought into driving connection with the output shaft via several selectively switchable spur gear stages. The superposition gear is arranged coaxially above a free end of the output shaft.The first input element is rotationally fixedly connected to a hollow shaft arranged coaxially above the output shaft, which can be rotationally fixedly connected to the idler gear of an immediately axially adjacent spur gear stage via a coupling switching element, which can be locked to the housing via a locking switching element, and which can be rotationally fixedly connected to the second input element or to the output element via a bridging switching element. The second input element of the superposition gear is permanently drive-connected to the rotor of the electric machine, in which case the output element of the superposition gear is rotationally fixedly connected to the output shaft. The input shaft of the manual transmission can be drive-connected to the second input element of the superposition gear via a coupling spur gear stage comprising a drive gear and an output gear and switchable by means of a second coupling switching element.

[0009] Furthermore, DE 10 2016 213 733 A1 shows a multi-stage transmission with an input shaft axis and an output shaft axis, which are arranged axially offset from one another. At least one first shaft is arranged coaxially to the input shaft axis as the input, and at least one second shaft is arranged coaxially to the output shaft axis as the output, with five further shafts being provided. A first spur gear stage, a second spur gear stage, a third spur gear stage, and a planetary gear set are provided. Furthermore, four shifting elements are provided, so that at least four forward gears and at least one reverse gear can be shifted. The first shaft can be connected to a first element and / or a third element of the planetary gear set via the first spur gear stage. The first shaft is connected to a second element of the planetary gear set via the third spur gear stage. Furthermore, the second shaft is connected to the third element of the planetary gear set.

[0010] Further generic hybrid transmissions are disclosed in DE 10 2020 202 652 A1, DE 10 2016 225 236 A1 and WO 2021 / 093 930 A1.

[0011] Against this background, a person skilled in the art is faced with the task of creating a compact hybrid transmission with a simple mechanical design. Furthermore, a drivetrain configuration should preferably be implemented in which the hybrid transmission is positioned coaxially to the output shafts and the combustion engine and / or the electric drive motor can be arranged axially parallel to it. In particular, a transmission is to be created that has up to four gear ratios and enables loading-to-neutral, electrodynamic starting (EDA), and electrodynamic shifting (EDS).

[0012] The above task is solved by a hybrid transmission for a motor vehicle drive train of a motor vehicle, with: a first transmission input shaft for operatively connecting the hybrid transmission to an internal combustion engine of the motor vehicle; a second transmission input shaft for operatively connecting the hybrid transmission to a first electric drive motor of the motor vehicle; an output shaft for operatively connecting the hybrid transmission to an output; a planetary gear set connected to the first transmission input shaft and to the output shaft; spur gear pairs arranged in several gear set levels to form gear steps; and several gearshift devices with switching elements for engaging gear steps, whereby the output shaft is of countershaft design; the second transmission input shaft is drivingly connected to one of the spur gear pairs to form gear steps; the second transmission input shaft is connectable to a ring gear or a sun gear of the planetary gear set; and a switching element for engaging an electric gear stage can be combined with another switching element to form a double switching element.

[0013] The above object is further achieved by a motor vehicle drive train for a motor vehicle, comprising: a hybrid transmission as previously defined; an internal combustion engine connectable to the first transmission input shaft; and a first electric drive motor which is drivingly connected to the second transmission input shaft.

[0014] The above object is also achieved by a method for operating a motor vehicle drive train as previously defined.

[0015] The above task is finally solved by a motor vehicle with: a motor vehicle powertrain as previously defined; and an energy storage device for storing energy to supply the first electric drive machine and / or a second electric drive machine.

[0016] Preferred embodiments of the invention are described in the dependent claims. It is understood that the features mentioned above and those to be explained below can be used not only in the respective combinations specified, but also in other combinations or on their own, without departing from the scope of the present invention. In particular, the motor vehicle drive train, the motor vehicle, and the method can be designed according to the embodiments described for the hybrid transmission in the dependent claims.

[0017] A compact hybrid transmission can be created in a technically simple manner by using a first transmission input shaft for operatively connecting the hybrid transmission to an internal combustion engine and a second transmission input shaft for operatively connecting the hybrid transmission to a first electric drive motor. An operative connection can be designed to be either switchable or non-switchable. A compact hybrid transmission can be created by using an output shaft for operatively connecting the hybrid transmission to an output, which is designed in a countershaft design. In particular, the output shaft can be regarded as a countershaft or as a partial countershaft. In particular, it is conceivable to design the output shaft as a hollow shaft and to arrange it around another countershaft. Consequently, a hybrid transmission can be created in which the countershaft also functions as an output shaft and is arranged axially parallel to the first and second transmission input shafts.A planetary gear set connected to the first transmission input shaft and the output shaft allows for the creation of a compact hybrid transmission with a wide range of functions. The fact that a shifting element for engaging an electric gear stage can be combined with another shifting element to form a double shifting element increases the compactness of the hybrid transmission. The shifting element is designed and configured for combination with another shifting element. In particular, a hybrid transmission can be created that enables load-to-neutral as well as electrodynamic starting and electrodynamic gear shifts. In particular, a hybrid transmission with a simple design and only three actuators can be created with a compact construction. The hybrid transmission features low component loads, low transmission losses, and good gearing efficiency, both in terms of the combustion engine and electrical system.The transmission enables power-assisted gearshifts. In particular, the first electric drive motor can be decoupled in two of the gear ratios, enabling highly efficient, purely combustion-engine operation. A transition from the charge-to-neutral state or from electrodynamic start-up can occur in all three mechanical gear ratios for the combustion engine.

[0018] In an advantageous embodiment, the second transmission input shaft can be connected to the first electric drive motor by means of a third spur gear pair of the spur gear pairs to form gear steps. Alternatively, the second transmission input shaft comprises a connecting gear and can be connected to the first electric drive motor by means of the connecting gear. By connecting the first electric drive motor by means of the third spur gear pair, a weight-optimized drive train can be created. In particular, fewer components are required to construct the drive train. A connecting gear can achieve greater flexibility for a pre-transmission of the first electric drive motor.

[0019] In a further advantageous embodiment, in a first spur gear pair for forming the gear steps, the arrangement of the idler gear is interchangeable with the arrangement of the fixed gear. This improves the variability of the hybrid transmission. In particular, the hybrid transmission can be better adapted to installation space requirements. Additionally or alternatively, the output shaft has a fixed gear of a second spur gear pair of the spur gear pairs for forming the gear steps. This enables efficient power transmission to the output shaft. In particular, power transmission can occur by switching only one or two switching elements. Furthermore, additionally or alternatively, a third spur gear pair of the spur gear pairs is drive-effectively connected to the second transmission input shaft for forming the gear steps. This allows drive power from the electric drive motor to be efficiently transmitted in the hybrid transmission.In particular, an electric gear stage can be set up by inserting a single switching element.

[0020] In a further advantageous embodiment, the hybrid transmission has a transmission input shaft that is drivingly connected to the first transmission input shaft and arranged axially parallel to the first transmission input shaft. Additionally or alternatively, the output shaft is drivingly connected to a differential of the output, wherein the differential comprises a differential shaft for transmitting drive power from the hybrid transmission to wheels of the motor vehicle, which differential shaft is arranged axially parallel to the output shaft and is designed to support the first electric drive motor. Preferably, the transmission input shaft is drivingly connected to the first transmission input shaft by means of a chain or a gear chain. The advantageous arrangement described above enables the combustion engine to be connected axially parallel to a transmission axle of the hybrid transmission.It goes without saying that an additional damper or damping element can be arranged on the transmission input shaft. By mounting the first electric drive motor on a transmission shaft, a highly efficient and space-saving mounting or arrangement of the first electric drive motor in the hybrid transmission can be achieved. The compactness of the hybrid transmission can be further improved.

[0021] In a further advantageous embodiment, a planetary gear carrier of the planetary gear set is connected to the output shaft by means of a second spur gear pair of the spur gear pairs to form the gear stages. Additionally, a sun gear of the planetary gear set is connected to the first transmission input shaft. Furthermore, a ring gear of the planetary gear set can be connected to the second transmission input shaft. This advantageous connection of the planetary gear set allows the first electric motor and the combustion engine to establish an electrodynamic superposition state with the planetary gear set, which can be further increased by means of the planetary gear carrier via the second spur gear pair. A highly variable hybrid transmission with an advantageously increased and integrated electrodynamic starting element can be created.

[0022] In a further advantageous embodiment, the hybrid transmission has an internal combustion engine clutch for releasably and driveably connecting the first transmission input shaft to the internal combustion engine, wherein the internal combustion engine clutch is preferably arranged on the transmission input shaft. It is understood that the internal combustion engine clutch can be designed as a dog-type shift element or as a friction shift element. An internal combustion engine clutch can decouple the internal combustion engine from the hybrid transmission, thus enabling a highly efficient, all-electric driving mode using the hybrid transmission. A friction clutch also enables a so-called momentum start of the internal combustion engine and can serve as a starting element for the internal combustion engine. An internal combustion engine clutch can increase the variability and efficiency of the hybrid transmission.Furthermore, an internal combustion engine clutch can be used in a hybrid transmission for functional safety reasons.

[0023] According to the invention, a first shifting element is designed to block the planetary gear set. According to the invention, a second shifting element is designed to drive-effectively connect the second transmission input shaft to the output shaft by means of a second spur gear pair of the spur gear pairs to form the gear stages. Furthermore, according to the invention, a third shifting element is designed to drive-effectively connect the planetary gear set, in particular a ring gear of the planetary gear set, to the second transmission input shaft. Furthermore, according to the invention, a fourth shifting element is designed to drive-effectively connect the first transmission input shaft to the second transmission input shaft. Furthermore, according to the invention, a fifth shifting element is designed to drive-effectively connect the first transmission input shaft to the output shaft by means of a first spur gear pair of the spur gear pairs to form the gear stages.Finally, according to the invention, a sixth shifting element is further configured to drive-connect the second transmission input shaft to the output shaft by means of a third spur gear pair of the spur gear pairs to form the gear ratios. This advantageous arrangement of the shifting elements allows the hybrid transmission to provide four hybrid gear ratios, with several variants, as well as a pure electric gear ratio and preferably another electric gear ratio with a shorter ratio. A variable and compact hybrid transmission can be created, enabling electrodynamic starting, electrodynamic shifting, and charging-to-neutral.

[0024] In a further advantageous embodiment, the output shaft is designed as a solid shaft and is at least partially surrounded by an intermediate shaft. Alternatively, the output shaft is designed as a hollow shaft and at least partially surrounds the intermediate shaft, which is drive-connected to a third spur gear pair of the spur gear pairs to form the gear stages. The output shaft can be drive-connected to the intermediate shaft or an idler gear of a second spur gear pair of the spur gear pairs to form the gear stages. This makes it possible to create a compact hybrid transmission with variable installation space.

[0025] In a further advantageous embodiment, the shifting elements are designed as positive-locking shifting elements. Additionally or alternatively, at least two of the shifting elements, preferably four shifting elements, particularly preferably six shifting elements, are designed as double shifting elements and can be actuated by a double-acting actuator. Positive-locking shifting elements enable a highly efficient and cost-effective hybrid transmission. The technical design and operation of the hybrid transmission can be further simplified by a double shifting element. In particular, a double shifting element can be switched using a single actuator.

[0026] In a further advantageous embodiment, the motor vehicle drive train preferably comprises a further electric machine that is drivingly connected to the first transmission input shaft. The first electric drive machine and / or preferably the further electric machine can be controlled as a starter generator for starting the internal combustion engine. Additionally or alternatively, the first electric drive machine and / or preferably the further electric machine can be controlled as a charging generator for charging an energy storage device. The further electric machine is preferably designed as a high-voltage starter generator. This makes it possible to create an efficient motor vehicle drive train. In particular, fuel consumption can be reduced.It is understood that an additional starter for the combustion engine can be dispensed with, since the first electric drive motor and / or preferably the further electric motor can tow the combustion engine.

[0027] In a further advantageous embodiment, an output of the hybrid transmission can be drive-connected to a first motor vehicle axle, wherein a second motor vehicle axle comprises an electric axle with a second electric drive motor. This makes it technically simple to create a hybrid drive train with all-wheel drive. Furthermore, the motor vehicle drive train can easily enable shifting without interruption in tractive force, since the electric axle can maintain tractive force during shifts in the hybrid transmission. Furthermore, a fail-safe drive train for a motor vehicle can be created, since a so-called serial driving mode can be set up in the event of a depleted energy storage device for the second electric drive motor.In serial driving mode, the electric drive motor is preferably operated by the internal combustion engine as a generator, and the energy thus generated is made available to the second electric drive motor. This allows for a highly variable motor vehicle drive train that can be driven and started electrically, especially when the energy storage device is empty.

[0028] Locking an element of a planetary gear set is understood in particular as blocking the element's rotation about its axis of rotation. Preferably, the element is connected in a rotationally fixed manner to a static component such as a frame and / or a transmission housing by means of a switching element. It is also conceivable to brake the element to a standstill.

[0029] Interlocking a planetary gear set involves connecting two gears and / or the planetary gear carrier and a gear of the planetary gear set in a drive-effective manner, so that they rotate together at the same speed around the same point, preferably the center of the planetary gear set. When interlocking two gears and / or a planetary gear carrier and a gear of the planetary gear set, the planetary gear set preferably acts like a shaft; in particular, no gear ratio is transmitted within the planetary gear set.

[0030] In this context, "drive-effectively connected" refers in particular to a non-switchable connection between two components intended for the permanent transmission of a rotational speed, torque, and / or drive power. The connection can be made either directly or via a fixed transmission ratio. The connection can be made, for example, via a fixed shaft, a gearing, in particular a spur gearing, and / or a belt drive, in particular a traction drive.

[0031] In this context, "drive-connectable," "can be connected to a drive," or "is designed for a drive-connected connection" refers, in particular, to a switchable connection between two components, which, in a closed state, is intended for the temporary transmission of a rotational speed, a torque, and / or a drive power. In an open state, the switchable connection preferably temporarily transmits essentially no rotational speed, no torque, and / or no drive power.

[0032] Stand-by charging or charging-in-neutral means, in particular, operating the electric drive motor as a generator, preferably when stationary with the combustion engine running, in order to fill an energy storage unit and / or to supply on-board electronics.

[0033] In this context, an actuator is, in particular, a component that converts an electrical signal into a mechanical movement. Actuators used with dual switching elements preferably perform movements in two opposite directions, switching one switching element of the dual switching element in the first direction and switching the other switching element in the second direction.

[0034] A gear change, particularly a serial shift, occurs in particular by disengaging a shifting element and / or a clutch and simultaneously engaging the shifting element and / or the clutch for the next higher or lower gear. The second shifting element and / or the second clutch thus gradually takes over the torque from the first shifting element and / or the first clutch until, at the end of the gear change, the entire torque is taken over by the second shifting element and / or the second clutch. With prior synchronization, a gear change can occur more quickly; positive-locking shifting elements can preferably be used.

[0035] An internal combustion engine can be any machine that can generate a rotary motion by burning a fuel such as gasoline, diesel, kerosene, ethanol, liquefied petroleum gas, LPG, etc. An internal combustion engine can be, for example, a gasoline engine, a diesel engine, a rotary engine, or a two-stroke engine.

[0036] In serial driving or crawling, an electric drive motor of a motor vehicle is powered by a combustion engine of the motor vehicle. The energy thus generated is then made available to another electric drive motor of the motor vehicle to provide drive power.

[0037] An electric vehicle axle, or simply an electric axle, is preferably a non-main drive axle of a motor vehicle, in which drive power can be transferred to the wheels of the motor vehicle by means of an electric drive motor. It is understood that the electric drive motor can also be connected via a transmission. Traction can be fully or partially maintained by means of an electric axle when a gear change occurs in the transmission for a main drive axle. Furthermore, all-wheel drive functionality can be implemented at least partially by means of an electric axle.

[0038] An electrodynamic starting element (EDA) ensures that the speed of the combustion engine and the electric drive motor is superimposed via one or more planetary gear sets, enabling a motor vehicle to start from a standstill with the combustion engine running, preferably without a friction clutch. The electric drive motor supports a torque. Preferably, the combustion engine can no longer be separated from the transmission by a starting clutch or the like. By using an EDA, the starter, generator, and starting clutch or hydrodynamic converter can be eliminated. In particular, an EDA is so compact that all components fit into the standard clutch housing without extending the transmission.The electrodynamic starting element can, for example, be firmly connected to an internal combustion engine, and in particular to a flywheel of an internal combustion engine, via a softly tuned torsional damper. This allows the electric drive motor and the internal combustion engine to be operated either simultaneously or alternatively. When the vehicle stops, the electric drive motor and the internal combustion engine can be switched off. Due to the good controllability of the electric drive motor, a very high starting quality is achieved, which can be equivalent to that of a drive with a torque converter clutch.

[0039] In an electrodynamic shift (EDS), as with EDA starting, the speed of the combustion engine and the electric drive motor is superimposed via one or more planetary gear sets. At the start of the shift, the torques of the electric drive motor and the combustion engine are adjusted so that the shift element to be disengaged is load-free. After this shift element is opened, the speed is adjusted while maintaining the tractive force, so that the shift element to be engaged becomes synchronous. After the shift element is closed, the load is distributed between the combustion engine and the electric drive motor as desired, depending on the hybrid operating strategy.The electrodynamic shifting system has the advantage that the shift element of the target gear to be engaged is synchronized through the interaction of the electric drive motor and the combustion engine, with the electric drive motor preferably being precisely controllable. A further advantage of the EDL shifting system is that high tractive effort can be achieved, since the torques of the combustion engine and the electric motor are combined in the hybrid transmission.

[0040] The invention is described and explained in more detail below using selected embodiments in conjunction with the accompanying drawings. They show: Fig. 1 a schematic plan view of a motor vehicle with a motor vehicle drive train according to the invention; Fig. 2 is a schematic diagram of an explanatory example of a hybrid transmission; Fig. 3 schematically shows the switching states of the hybrid transmission according to the Fig. 2; Fig. 4 a schematic representation of a variant of a hybrid transmission according to the invention; Fig. 5 is a schematic diagram showing an explanatory example of the hybrid transmission; Fig. 6 is a schematic diagram showing an explanatory example of the hybrid transmission; Fig. 7 is a schematic diagram showing an explanatory example of the hybrid transmission; Fig. 8 is a schematic diagram showing an explanatory example of the hybrid transmission; Fig. 9 is a schematic diagram showing an explanatory example of the hybrid transmission; Fig. 10 is a schematic diagram of an explanatory example of the hybrid transmission; and Fig. 11 is a schematic diagram of an explanatory example of the hybrid transmission.

[0041] In Fig. 1 schematically shows a motor vehicle 10 with a motor vehicle drive train 12. The motor vehicle drive train 12 has a first electric drive motor 14 and an internal combustion engine 16, which are connected to a front axle of the motor vehicle 10 by means of a hybrid transmission 18. In the example shown, the motor vehicle drive train 12 further comprises an optional electric axle with a second electric drive motor 20, which is connected to a rear axle of the motor vehicle 10. It is understood that a reverse connection can also be made, so that the hybrid transmission 18 is connected to the rear axle of the motor vehicle 10 and the front axle of the motor vehicle 10 comprises the electric axle.By means of the motor vehicle drive train 12, drive power of the first electric drive motor 14, the internal combustion engine 16, and / or the optional second electric drive motor 20 is supplied to the wheels of the motor vehicle 10. The motor vehicle 10 further comprises an energy storage device 22 for storing energy that serves to supply the first electric drive motor 14 and / or the second electric drive motor 20.

[0042] Fig. 2 shows an illustrative example of an exemplary hybrid transmission 18. The hybrid transmission 18 has a first transmission input shaft 24 and a second transmission input shaft 26, which are configured to transmit drive power from the prime movers 14, 16 into the hybrid transmission 18.

[0043] The hybrid transmission 18 further includes an output shaft 28 and a planetary gear set RS. The output shaft 28 is designed as a hollow shaft and is arranged on a first intermediate shaft 30 designed as a solid shaft. A total of three spur gear pairs, designated ST1 to ST3, are arranged in the hybrid transmission 18. The planetary gear set RS is connectable to the second transmission input shaft 26 by means of a further intermediate shaft 32.

[0044] The hybrid transmission 18 has a first shift element A, an optional second shift element B, as in Fig. 4, for example, and a third to sixth switching element C to F. The Fig. The hybrid transmission 18 shown in Figure 2 has a total of five switching elements A, C to F.

[0045] The first spur gear pair ST1 is formed by a loose gear arranged on the first intermediate shaft 30 and a fixed gear arranged on the first transmission input shaft 24, wherein the first spur gear pair ST1 can be switched to drive operation by engaging a fifth shift element E. Consequently, by engaging the fifth shift element E, drive power is transmitted from the first transmission input shaft 24 via the first spur gear pair ST1 to the output shaft 28.

[0046] The second spur gear pair ST2 is formed by a fixed gear arranged on the output shaft 28 and an idler gear arranged on the first transmission input shaft 24 and can be engaged in drive mode by engaging a first shifting element A. The idler gear of the second spur gear pair ST2 is also drive-connected to a planetary gear carrier of the planetary gear set.

[0047] The third spur gear pair ST3 is formed by a fixed gear arranged on the second transmission input shaft 26, which is in engagement with a fixed gear arranged on the first intermediate shaft 30, wherein the first intermediate shaft 30 can be connected in a drivingly effective manner to the output shaft 28 by engaging a sixth shift element F.

[0048] A ring gear of the planetary gear set RS is drive-connected to the further intermediate shaft 32. Furthermore, a sun gear of the planetary gear set RS is drive-connected to the first transmission input shaft 24.

[0049] By engaging the first shift element A, the RS planetary gear set can be locked. In the example shown, the first shift element A connects the planetary gear carrier of the RS planetary gear set to the sun gear of the RS planetary gear set in a drive-effective manner.

[0050] A third shift element C connects the second transmission input shaft 26 in a drive-effective manner with the further intermediate shaft 32 and consequently with the ring gear of the planetary gear set RS.

[0051] A fourth shift element D connects the first transmission input shaft 24 to the second transmission input shaft 26 in a drive-effective manner.

[0052] The third shift element C is combined with the fourth shift element D to form a double shift element and is arranged on the first transmission input shaft 24 or the second transmission input shaft 26. The fifth shift element E is combined with the sixth shift element F to form a double shift element. This double shift element is arranged on the output shaft 28 or the first intermediate shaft 30.

[0053] The first shifting element A is designed as a single shifting element and is arranged on the first transmission input shaft 24.

[0054] The output shaft 28 is designed to transmit drive power from the hybrid transmission 18 to an output 34 (not shown in detail). In the example shown, the first electric drive motor 14 is connected to the hybrid transmission 18 on a transmission side opposite the connection side of the combustion engine 16 (not shown).

[0055] The first shift element A, when closed, blocks the planetary gear set RS by connecting two of the three elements of the planetary gear set RS. The following three blocking variants are conceivable. The first shift element A could connect the sun gear and the planetary gear carrier of the planetary gear set RS, as shown in Fig. 2. Furthermore, the first shifting element A could connect the ring gear of the planetary gear set RS with the planetary gear carrier of the planetary gear set RS. Finally, the first shifting element A could also connect the sun gear with the ring gear of the planetary gear set RS.

[0056] Preferably, the drives, i.e. the combustion engine 16 and the first electric drive motor 14, are arranged axially parallel to the hybrid transmission 18. It is understood that the Fig. 2, a fixed transmission in the form of another planetary gear set or a spur gear stage can be connected downstream. Furthermore, it is understood that the Fig. 2 shown wheel set is usually followed by a differential.

[0057] In Fig. 3, a shift matrix 36 shows the hybrid gear stages H1 to H4, an electric gear stage E1, an electrodynamic superposition state EDA, and a charge-in-neutral state (LiN). The second to sixth columns show the shift states of the shift elements A, C, D, E, and F, where an "X" means that the respective shift element is closed, i.e., connects the associated transmission components to one another in a drive-effective manner. If no entry is present, it can be assumed that the corresponding shift element is open, i.e., not transmitting any drive power.

[0058] A first variant of the first hybrid gear stage H1.1 can be set up by engaging the third shift element C and the fifth shift element E.

[0059] A second variant of the first hybrid gear stage H1.2 can be set up by engaging the fourth shift element D and the fifth shift element E.

[0060] Engaging the fifth shift element E sets up a third variant of the first hybrid gear stage H1.3.

[0061] The second hybrid gear stage H2 can be set by engaging the third shift element C and the sixth shift element F.

[0062] A first variant of the third hybrid gear stage H3.1 can be set up by engaging the first shift element A and the sixth shift element F.

[0063] Engaging the first shift element A and the third shift element C sets up a second variant of the third hybrid gear stage H3.2.

[0064] A third variant of the third hybrid gear stage H3.3 can be set up by engaging the first shift element A and the fourth shift element D.

[0065] Engaging the first shift element A sets up a fourth variant of the third hybrid gear stage H3.4.

[0066] The fourth hybrid gear stage H4 can be set by engaging the fourth shift element D and the sixth shift element F.

[0067] The electric gear stage E1 can be set by engaging the sixth switching element F.

[0068] Inserting the third switching element C establishes an electrodynamic superposition state EDA.

[0069] The charge-in-neutral, LiN, state can be set by engaging the fourth switching element D.

[0070] For combustion engine or hybrid driving, three or four different hybrid gear ratios are available for the combustion engine 16. The first hybrid gear ratio H1 and the second hybrid gear ratio H2 have similar gear ratios. The second hybrid gear ratio H2 is required in particular to enable gear ratios with output-assisted shifting.

[0071] If only the sixth switching element F is closed, driving is possible purely electrically, since the first electric drive motor 14 is directly connected to the output 34.

[0072] If only the third shifting element C is closed, an EDA state, i.e. an electrodynamic superposition state, arises on the planetary gear set RS. The internal combustion engine 16 is then connected to the sun gear of the planetary gear set RS, with the first electric drive motor 14 supporting the torque of the internal combustion engine 16 on the ring gear of the planetary gear set. The planet gear carrier of the planetary gear set RS is connected to the output 34 via the second spur gear pair ST2. This enables what is known as EDA forward starting. From this EDA mode or shifting state, the first variant of the first hybrid gear stage H1.1, the second hybrid gear stage H2, and the second variant of the third hybrid gear stage H3.2 can be engaged for the internal combustion engine 16, because the third shifting element C is closed in each of these shifting states.

[0073] A shift from the second gear to the third gear can be performed with output support by the first electric drive motor 14, with the sixth shift element F remaining closed. The shift then takes place from the second hybrid gear H2 to the first variant of the third hybrid gear H3.1. Furthermore, a shift from the third gear to the fourth gear can also be performed with output support by the first electric drive motor 14, with the sixth shift element F remaining closed. In this case, the shift takes place from the first variant of the third hybrid gear H3.1 to the fourth hybrid gear H4.

[0074] An electromechanical (EMS) or an electrodynamic (EDS) powershift from the second hybrid gear stage H2 to the first variant of the third hybrid gear stage H3.1 in hybrid mode can, for example, be carried out as follows. In the starting point, i.e., the second hybrid gear stage H2, the third shifting element C and the sixth shifting element F are closed. A load reduction occurs on the third shifting element C and a simultaneous load buildup on the first electric drive motor 14. The third shifting element C is then opened. The speed of the internal combustion engine 16 is reduced so that the first shifting element A becomes synchronous. For this purpose, for example, the internal combustion engine 16 can drive another electric drive motor in a generator capacity, which is preferred, or the internal combustion engine 16 can go into overrun mode. The first shifting element A can then be engaged. The sixth shifting element F remains closed during the shift.

[0075] If only the fourth switching element D is closed, the first electric drive motor 14 can be connected to the internal combustion engine 16 independently of the output 34. The first electric drive motor 14 and the internal combustion engine 16 then rotate in a fixed relationship to one another. Thus, on the one hand, the internal combustion engine 16 can be started using the first electric drive motor 14. Furthermore, the first electric drive motor 14 can be operated by the internal combustion engine 16 as a generator and charge the electrical energy storage device 22 or supply electrical consumers.

[0076] A consumer may also use a second electric drive machine 20, as in Fig. 1, which, for example, drives the other vehicle axle. A transition from the charging-to-neutral state (LiN) is possible to the second variant of the first hybrid gear stage H1.2, to the third variant of the third hybrid gear stage H3.3, and to the fourth hybrid gear stage H4 because the fourth shift element D is closed in each of these shift states.

[0077] Is, as for example in Fig. 1, an electric rear axle is present, an all-wheel drive system can be created using this combination. For example, a DHT transmission, i.e., a Dedicated Hybrid Transmission, with the combustion engine 16 and the first electric drive motor 14, can be designed as a pure front-wheel drive, with additional rear-axle drive being provided by the separate second electric drive motor 20.

[0078] In this case, the electrodynamic superposition state EDA is a power-split E-CVT driving range for the internal combustion engine 16, which also allows battery-neutral operation. The term "CVT" refers specifically to a continuously variable transmission (CVT).

[0079] In the first gear and the third gear, the first electric drive motor 14 can be decoupled, particularly in the third variant of the first hybrid gear H1.3 and the fourth variant of the third hybrid gear H3.4, when only the first shifting element A or the fifth shifting element E is engaged. This is particularly advantageous because it avoids no-load losses when the first electric drive motor 14 is not needed. An example of such a mode is driving purely with the combustion engine.

[0080] If the motor vehicle 10 is driven exclusively by the electric axle or the second electric drive unit 20, a large part of the hybrid transmission 18 can be decoupled by opening the first shifting element A, the fifth shifting element E, and the sixth shifting element F, respectively. This leads to fewer drag losses in the transmission gear set.

[0081] Furthermore, traction assistance can be provided by the second electric drive motor 20. The second electric drive motor 20 can, for example, support the traction at the rear axle when shifts are necessary in the hybrid transmission 18, during which the output 34 of the hybrid transmission 18 becomes load-free. An example of such a transition is: when the vehicle is initially driven purely electrically by the first electric drive motor 14 and / or the second electric drive motor 20 and then the combustion engine 16 is to be started in neutral by the first electric drive motor 14.

[0082] In Fig. 4 shows a preferred embodiment of a hybrid transmission 18 according to the invention. In contrast to the Fig. 2, the hybrid transmission 18 comprises the Fig. 4, the second shifting element B, which is designed to drive-connect the second transmission input shaft to the second spur gear pair ST2. The second shifting element B is combined with the first shifting element A to form a double shifting element.

[0083] Consequently, the Fig. 4, the embodiment shown uses exclusively dual shift elements. By engaging the second shift element B, an additional, shorter-ratio, purely electric gear stage can be created. This newly created shorter-ratio electric gear stage is preferably required for reversing, since no corresponding EDA mode is available for reversing.

[0084] In Fig. 5 shows another illustrative example of the hybrid transmission 18. In contrast to the Fig. The embodiment shown in Figure 2 shows an alternative locking variant for the planetary gear set RS. Fig. In the example shown in Figure 5, the first shifting element A blocks the planetary gear set RS by connecting the ring gear of the planetary gear set RS to the planetary gear carrier of the planetary gear set RS. For this purpose, in contrast to the Fig. In the embodiment shown in Figure 2, the second spur gear pair ST2 has a further shaft which is guided radially outwardly around the planetary gear set RS so that it can be switched by means of the first switching element A.

[0085] In Fig. 6 shows another illustrative example of the hybrid transmission 18. In contrast to the Fig. In the embodiment shown in Figure 2, the output shaft 28 is designed as a solid shaft, with the first intermediate shaft 30 being designed as a hollow shaft and at least partially surrounding the output shaft 28. However, the connections to the shafts remain identical to the connections according to Fig. 2.

[0086] In Fig. 7 shows another illustrative example of the hybrid transmission 18. In contrast to the Fig. In the embodiment shown in Figure 2, the first electric drive machine 14 is drivingly connected to the fixed gear of the third spur gear pair ST3 arranged on the first intermediate shaft 30. The first electric drive machine 14 therefore has an output shaft on which a gear is arranged, which meshes with the fixed gear of the third spur gear pair ST3 arranged on the first intermediate shaft 30. In the embodiments shown so far, the gear arranged on the output shaft of the first electric drive machine 14 meshes with the fixed gear of the third spur gear pair ST3 arranged on the second transmission input shaft 26.

[0087] In Fig. 8 shows another illustrative example of the hybrid transmission 18. In contrast to the Fig. In the embodiment shown in Figure 2, the second transmission input shaft 26 has a connecting gear that meshes, via another gear, with the gear arranged on the output shaft of the first electric drive motor 14. This allows for greater flexibility with regard to the pre-ratio of the first electric drive motor 14 when introducing drive power into the hybrid transmission 18. Furthermore, this allows for design advantages with regard to the positioning of the first electric drive motor 14 in the engine compartment.

[0088] In Fig. 9 shows another illustrative example of the hybrid transmission 18. The hybrid transmission 18 according to the Fig. 9 essentially corresponds to the Fig. 7 shown hybrid transmission 18, wherein in Fig. 9, the output 34 is shown in more detail. The output 34 is formed by a fixed gear arranged on the output shaft 28 between the second spur gear pair ST2 and the third spur gear pair ST3. This fixed gear meshes with a fixed gear arranged on a differential and thus transmits drive power from the hybrid transmission 18 to the differential. The differential further has a differential shaft that penetrates a rotor shaft of the first electric drive motor 14. In other words, the first electric drive motor 14 is mounted on the differential shaft.

[0089] Furthermore, the hybrid transmission 18 has a transmission input shaft 38, which is arranged axially parallel to the first transmission input shaft 24 and is drivingly connected to the first transmission input shaft 24 via a traction mechanism transmission with a fixed gear arranged on an outer side of the transmission. The transmission input shaft 38 is connected to the combustion engine 16 via a torsional vibration damper or another element known in principle in the prior art for torsional vibration decoupling. Furthermore, a fixed gear for connecting a further electric machine 40 is arranged on the transmission input shaft 38. The further electric machine 40 is operatively connected to the transmission input shaft 38 via a traction mechanism transmission. Particularly preferably, the further electric machine 40 can be designed as a high-voltage starter generator.

[0090] It is understood that the connection of the transmission drive shaft 38 to both the first transmission input shaft 24 and the further electric machine 40 can alternatively also be designed as a gear chain.

[0091] In Fig. 10 shows another illustrative example of the hybrid transmission 18. In contrast to the Fig. In the embodiment shown in Figure 9, the transmission input shaft 38 comprises an internal combustion engine clutch K0. The internal combustion engine clutch K0 is designed to detachably drive-connect the transmission input shaft 38 to the internal combustion engine 16. The internal combustion engine clutch K0 is arranged between the torsional vibration decoupling element and the two connecting gears of the transmission input shaft 38, so that the additional electric machine 40 is always in drive connection with the first transmission input shaft 24.

[0092] In the Fig. In the example shown in Figure 10, the combustion engine clutch K0 is designed as a positive-locking switching element, for example as a claw clutch.

[0093] In Fig. 11 shows another illustrative example of the hybrid transmission 18. In contrast to the Fig. In the embodiment shown in Figure 10, the combustion engine clutch K0 is designed as a frictional switching element.

[0094] It is understood that the motor vehicle drive train 12 or the hybrid transmission 18 can also be operated without an internal combustion engine clutch K0. Nevertheless, an internal combustion engine clutch K0 can be useful for various reasons, such as functional safety. In particular, an internal combustion engine clutch K0 in the form of a friction-engaging switching element, as shown in Fig. 11, a tow start of the internal combustion engine 16. In particular, in an embodiment with an additional electric machine 40, an internal combustion engine clutch K0 is useful.

[0095] The invention has been comprehensively described and explained with reference to the drawings and the description. The description and explanation are to be understood as exemplary and not restrictive. The invention is not limited to the disclosed embodiments. Other embodiments or variations will become apparent to those skilled in the art upon use of the present invention and upon careful analysis of the drawings, the disclosure, and the following claims.

[0096] In the patent claims, the words "comprising" and "having" do not exclude the presence of further elements or steps. The undefined article "a" or "an" does not exclude the presence of a plurality. A single element or a single unit can perform the functions of several of the units recited in the patent claims. The mere mention of some measures in several different dependent patent claims should not be understood to mean that a combination of these measures cannot also be used advantageously. Reference symbols in the patent claims are not to be understood as limiting. A method for operating a motor vehicle drivetrain 12 can, for example, be implemented in the form of a computer program that is executed on a control unit for the motor vehicle drivetrain 12.

[0097] A computer program may be stored / distributed on a non-volatile storage medium, such as optical storage or a solid-state drive (SSD). A computer program may be distributed together with hardware and / or as part of hardware, such as via the Internet or via wired or wireless communication systems.

[0098] Fig. 2, Fig. 3, Fig. 5, Fig. 6, Fig. 7, Fig. 8, Fig. 9, Fig. 10 and Fig. 11 merely show illustrative examples (where previously "a variant" or "a further variant" was written), which do not belong to the invention as literally defined in the claims. Reference symbol 10 motor vehicle 12 Automotive powertrain 14 first electric drive machine 16 Combustion engine 18 hybrid transmissions 20 second electric drive motor 22 energy storage 24 first transmission input shaft 26 second transmission input shaft 28 Output shaft 30 first intermediate shaft 32 additional intermediate shafts 34 downforce 36 Switch matrix 38 Gearbox drive shaft 40 additional electric machines A to F switching elements K0 internal combustion engine clutch ST1 first spur gear pair ST2 second spur gear pair ST3 third spur gear pair

Claims

[1] Hybrid transmission (18) for a motor vehicle drive train (12) of a motor vehicle (10), comprising: a first transmission input shaft (24) for operatively connecting the hybrid transmission (18) to an internal combustion engine (16) of the motor vehicle; a second transmission input shaft (26) for operatively connecting the hybrid transmission (18) to a first electric drive motor (14) of the motor vehicle; an output shaft (28) for operatively connecting the hybrid transmission (18) to an output (34); a planetary gear set (RS) connected to the first transmission input shaft (24) and to the output shaft (28); spur gear pairs (ST1, ST2, ST3) arranged in several gear set levels to form gear steps; and several gearshift devices with shift elements (A, B, C, D, E, F) for engaging gear steps, wherein a first shifting element (A) is designed to block the planetary gear set (RS); a second shift element (B) is designed to drive-effectively connect the second transmission input shaft (26) to the output shaft (28) by means of a second spur gear pair (ST2) of the spur gear pairs (ST1, ST2, ST3) to form the gear stages; a third shift element (C) is designed to drive-effectively connect the planetary gear set (RS) to the second transmission input shaft (26); a fourth shift element (D) is designed to drive-effectively connect the first transmission input shaft (24) to the second transmission input shaft (26); a fifth shift element (E) is designed to drive-effectively connect the first transmission input shaft (24) to the output shaft (28) by means of a first spur gear pair (ST1) of the spur gear pairs (ST1, ST2, ST3) to form the gear stages; and a sixth shift element (F) is designed to drive-effectively connect the second transmission input shaft (26) to the output shaft (28) by means of a third spur gear pair (ST3) of the spur gear pairs (ST1, ST2, ST3) to form the gear stages, wherein the output shaft (28) is of countershaft design; the second transmission input shaft (26) is drivingly connected to one of the spur gear pairs (ST1, ST2, ST3) to form gear stages; the second transmission input shaft (26) is connectable to a ring gear or a sun gear of the planetary gear set (RS); and a switching element (A, B, C, D, E, F) for engaging an electric gear stage can be combined with another switching element to form a double switching element. [2] Hybrid transmission (18) according to claim 1, wherein the second transmission input shaft (26) is connectable to the first electric drive motor (14) by means of a third spur gear pair (ST3) of the spur gear pairs (ST1, ST2, ST3) to form gear stages; or the second transmission input shaft (26) comprises a connecting gear and can be connected to the first electric drive machine by means of the connecting gear. [3] Hybrid transmission (18) according to claim 1 or 2, wherein in a first spur gear pair (ST1, ST2, ST3) for forming the gear stages, an arrangement of the loose gear is interchangeable with the arrangement of the fixed gear; the output shaft (28) has a fixed gear of a second spur gear pair (ST2) of the spur gear pairs (ST1, ST2, ST3) for forming the gear stages; and / or a third spur gear pair (ST3) of the spur gear pairs (ST1, ST2, ST3) is drive-effectively connected to the second transmission input shaft (26) to form the gear stages. [4] Hybrid transmission (18) according to one of the preceding claims, wherein the hybrid transmission (18) has a transmission input shaft (38) which is drivingly connected to the first transmission input shaft (24) and is arranged axially parallel to the first transmission input shaft (24), and / or the output shaft (28) is drive-effectively connected to a differential of the output (34), wherein the differential comprises a differential shaft for transmitting drive power from the hybrid transmission (18) to wheels of the motor vehicle (10), which differential shaft is arranged axially parallel to the output shaft (28) and is designed to support the first electric drive machine (14). [5] Hybrid transmission (18) according to one of the preceding claims, wherein a planetary gear carrier of the planetary gear set (RS) is connected to the output shaft (28) by means of a second spur gear pair (ST2) of the spur gear pairs (ST1, ST2, ST3) to form the gear stages; a sun gear of the planetary gear set (RS) is connected to the first transmission input shaft (24); and a ring gear of the planetary gear set (RS) can be connected to the second transmission input shaft (26). [6] Hybrid transmission (18) according to one of the preceding claims, with an internal combustion engine clutch (K0) for releasably drivingly connecting the first transmission input shaft (24) to the internal combustion engine (16), wherein the internal combustion engine clutch (K0) is arranged on the transmission input shaft (38). [7] Hybrid transmission (18) according to one of the preceding claims, wherein the output shaft (28) is designed as a solid shaft and is surrounded at least in sections by a first intermediate shaft (30); or the output shaft (28) is designed as a hollow shaft and at least partially surrounds the intermediate shaft (30), which is drive-effectively connected to a third gear pair (ST3) of the spur gear pairs (ST1, ST2, ST3) to form the gear stages, wherein the output shaft (28) is drive-effectively connectable to the intermediate shaft (30) or to an idler gear of a second spur gear pair (ST2) of the spur gear pairs (ST1, ST2, ST3) to form the gear stages. [8] Hybrid transmission (18) according to one of the preceding claims, wherein the switching elements (A, B, C, D, E, F) are designed as positive-locking switching elements; and / or at least two of the switching elements (A, B, C, D, E, F) are designed as double switching elements and can be actuated by a double-acting actuator. [9] Motor vehicle drive train (12) for a motor vehicle (10), comprising: a hybrid transmission (18) according to one of the preceding claims; an internal combustion engine (16) connectable to the first transmission input shaft (24); and a first electric drive motor (14) which is drivingly connected to the second transmission input shaft (26). [10] Motor vehicle drive train (12) according to claim 9, wherein the motor vehicle drive train comprises a further electric machine (40) which is drivingly connected to the first transmission input shaft (24) and the first electric drive machine (14) and / or the further electric machine (40) can be controlled as a starter generator for starting the internal combustion engine (16); and / or can be controlled as a charging generator for charging an energy storage device (22). [11] Motor vehicle drive train (12) according to claim 9 or 10, wherein an output (34) of the hybrid transmission (18) is driveably connectable to a first motor vehicle axle and a second motor vehicle axle comprises an electric axle with a second electric drive machine (20). [12] Method for operating a motor vehicle drive train (12) according to one of claims 9 to 11. [13] Motor vehicle (10) comprising: a motor vehicle drive train (12) according to one of claims 9 to 11; and an energy storage device (22) for storing energy to supply the first electric drive machine (14) and / or the second electric drive machine (20).

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