Hybrid powertrain in mixed construction

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) with an internal combustion engine (16) of the motor vehicle (10); a second transmission input shaft (26) for connecting the hybrid transmission (18) with a first electric drive motor (14) of the motor vehicle (10); a first intermediate wave (30); a second intermediate shaft (32) which is connected to the first transmission input shaft (24) in a drive-effective manner; an output shaft (28) for connecting the hybrid transmission (18) with an output (38); a first planetary gear set (RS1) which is connected to the second transmission input shaft (26), the first intermediate shaft (30) and the output shaft (28); a countershaft (34); Spur gear pairs (ST1, ST2, ST3, ST4, ST5) arranged in several wheelset levels; and several gearshift devices with shifting elements (A, B, C, D, E, F) for engaging gear stages, wherein a gear of a first spur gear pair (ST1) and a gear of a third spur gear pair (ST3) are connected to each other in a driving manner; the second intermediate shaft (32) and another gear of the third spur gear pair (ST3) are connected to each other for driving purposes; the second intermediate shaft (32) and another gear of the third spur gear pair (ST3); the second transmission input shaft (26), the first intermediate shaft (30), the second intermediate shaft (32) and the output shaft (28) are arranged coaxially to each other; the first transmission input shaft (24), the second transmission input shaft (26), the first intermediate shaft (30), the second intermediate shaft (32) and the output shaft (28) are designed as hollow shafts; and the second transmission input shaft (26), the first intermediate shaft (30) and the second intermediate shaft (32) surround the output shaft (28) at least partially.

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 becomes part of the transmission.

[0006] The published patent application DE 10 2011 005 562 A1 relates to a manual transmission of a hybrid drive for a motor vehicle with two input shafts and a common output shaft. The first input shaft can be connected to the drive shaft of an internal combustion engine via a controllable separating clutch and can be brought into drive connection with the output shaft via a first group of selectively switchable gear sets. The second input shaft is in drive connection with the rotor of an electric machine operable as a motor and as a generator, as well as with the first input shaft, via a superposition gear designed as a planetary gear, and can be brought into drive connection with the output shaft via a second group of selectively switchable gear sets. Both input shafts can be brought into drive connection with one another via a switchable coupling device.For cost-effective production, it is provided that the manual transmission is derived from a dual-clutch transmission with two coaxial input shafts, the first input shaft of which is arranged centrally, the second input shaft of which is designed as a hollow shaft and is arranged coaxially above the first input shaft and the coupling device of which comprises a gear stage and / or a switchable clutch, which are provided instead of the gear set and its associated gear clutch which is assigned to the first input shaft in the underlying dual-clutch transmission and is arranged axially adjacent to the transmission-side end of the second input shaft.

[0007] The published patent application DE 10 2013 105 731 A1 relates to a power transmission device comprising: an electric auxiliary drive unit; a torque conversion device comprising a planetary gear having a first rotational element connected to the electric auxiliary drive unit, a second rotational element connected to an internal combustion engine, and a third rotational element operated as an output element; an input device comprising: a first input shaft selectively connected to the second rotational element by means of a clutch and provided with at least one input gear fixedly arranged thereon;and a second input shaft arranged on the same axis as the first input shaft without rotationally interfering with the first input shaft, directly connected to the third rotating element, selectively connected to the second rotating element by another clutch, and provided with at least one input gear fixedly mounted thereon; and a gear output device that converts torque from the input device and outputs the converted torque.

[0008] The published patent application DE 10 2018 116 613 A1 relates to a superposition transmission comprising: - a transmission input and a transmission output, between which - at least two parallel transmission branches are arranged, which - each have different gear ratios or can be switched to different gear ratios via switching elements, and which - each can be alternatively connected to the transmission output. The superposition transmission is characterized in that a controllable or adjustable speed / torque converter is arranged in each of the transmission branches or in operative connection with each of the transmission branches, which is capable of continuously operating at an intermediate speed between the gear ratios in order to enable a continuously adjustable speed between the transmission input and the transmission output.

[0009] US Pat. No. 5,713,425 A relates to a hybrid powertrain for a motor vehicle, comprising an internal combustion engine and transmission assembly providing a first selectably switchable, geared torque flow path to vehicle drive wheels, and an electric motor-generator unit defining a second, geared torque flow path disposed between the output of the first transmission torque flow path and the drive wheels. Through the use of a suitable control system, including the necessary control algorithms, the electric motor-generator unit can be operated to deliver torque to the drive wheels while the torque flow in the first torque flow path is interrupted during the occurrence of a gear change in the transmission assembly and upon clutch disengagement.This interactive control of two power sources can improve both vehicle drivability and engine exhaust emissions. Furthermore, the electric motor-generator unit in the second torque flow path can be used to instantly launch the vehicle electrically upon operator request.

[0010] The published patent application EP 3 261 233 A1 relates to a drive train for a vehicle with at least a first drive axle, with a drive engine and a multi-speed transmission kinematically connected to the drive engine via an input shaft and via at least one output shaft to the first drive axle, wherein the multi-speed transmission comprises the following: a first drive shaft and a second drive shaft, wherein each of the two concentric drive shafts has at least one drive gear; at least one output shaft, which is kinematically connected to the first drive axle, with a plurality of gears on the output shaft that mesh with the driving gears on the drive shafts, wherein the gears can be engaged with the shafts by means of couplings in order to establish a power flow from the drive shafts to the output shaft with different gear ratios; a first electric machine with a first rotor;a planetary gear set having a first connecting member connected to the first drive shaft and the input shaft, a second connecting member connected to the second drive shaft, and a third connecting member kinematically connected to the rotor of the first electric machine; a controllable lock-up clutch; and at least one second electric machine.

[0011] The published patent application DE 10 2017 221 775 A1 discloses a hybrid drive train for a vehicle having at least one internal combustion engine with a VM drive shaft, in particular a crankshaft, and at least one first electric machine with a first EM drive shaft, wherein the internal combustion engine and the first electric machine are designed to transmit a torque to at least one drive axle, and further having a transmission having a transmission input shaft and a transmission output shaft which is operatively connected to a first drive axle drivable by the internal combustion engine, wherein the transmission input shaft of the transmission is connected at least to the VM drive shaft of the internal combustion engine in order to transmit a torque from the internal combustion engine to the transmission input shaft and further to the first drive axle, wherein the transmission input shaft and the VM drive shaft of the internal combustion engine are arranged parallel to one another.

[0012] Against this background, a specialist faces the task of creating a hybrid transmission with a simple mechanical design. Specifically, a three- or four-speed hybrid transmission is to be created that enables electrodynamic starting, electrodynamic shifting, electromotive shifting, and charging to neutral. Furthermore, a drivetrain configuration should preferably be implemented in which the hybrid transmission is positioned coaxially to the output shafts and the combustion engine can be arranged axially parallel to it.

[0013] This 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; a first intermediate shaft; a second intermediate shaft which is drivingly connected to the first transmission input shaft; an output shaft for operatively connecting the hybrid transmission to an output; a first planetary gear set connected to the second transmission input shaft, the first intermediate shaft and the output shaft; a countershaft; spur gear pairs arranged in several gear set levels; and several gearshift devices with switching elements for engaging gear steps, whereby a gear of a first spur gear pair and a gear of a third spur gear pair are drivingly connected to one another; the second intermediate shaft and another gear of the third spur gear pair are drivingly connected to each other; the second intermediate shaft can be connected to the output shaft in a drive-effective manner; the second intermediate shaft is driveably connectable to the output shaft, the second transmission input shaft, the first intermediate shaft, the second intermediate shaft and the output shaft are arranged coaxially to one another; the first transmission input shaft, the second transmission input shaft, the first intermediate shaft, the second intermediate shaft and the output shaft are designed as hollow shafts; and the second transmission input shaft, the first intermediate shaft and the second intermediate shaft surround the output shaft at least in sections.

[0014] 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.

[0015] The above object is also achieved by a method for operating a motor vehicle drive train as previously defined.

[0016] 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 the second electric drive machine.

[0017] 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.

[0018] 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. In particular, a hybrid transmission can be created that is arranged around one of the vehicle shafts on the front axle, with the internal combustion engine and the first electric drive motor arranged axially parallel thereto. A first planetary gear set connected to the first transmission input shaft, a first intermediate shaft, and an output shaft makes it technically simple to create an EDA mode that enables electrodynamic starting and electrodynamic gear shifting. Furthermore, at least one ECVT mode can be configured.By drivingly connecting a gear of the first spur gear pair and a gear of the third spur gear pair, a compact hybrid transmission with few shift elements can be created. A second intermediate shaft, which is drivingly connected to another gear of the third spur gear pair, further increases the compactness and functionality of the hybrid transmission. In particular, this allows for a technically simple pre-transmission of the drive power of the electric drive motor. Due to the rotationally fixed connection of the gears of two spur gear pairs, these two connected spur gear pairs can be used to set gear ratios without having to engage a shift element to connect the two spur gear pairs. The compactness of the transmission is further improved.By connecting the second intermediate shaft to the output shaft, a direct gear decoupled from the first electric drive motor can be established.

[0019] In a preferred embodiment, a differential of the output comprises a differential shaft, which is designed as a solid shaft and is at least partially surrounded by the transmission shafts, in particular the output shaft. The axial length of the differential shaft is greater than the axial length of the output shaft. The differential shaft completely penetrates the output shaft. This allows the hybrid transmission to be advantageously arranged around the differential shaft, creating a compact drivetrain.

[0020] In a further advantageous embodiment, the hybrid transmission comprises a second planetary gear set, which is drive-connected to the output shaft and an output differential. Preferably, a ring gear is fixed in the second planetary gear set, a planetary gear carrier is drive-connected to the output differential, and a sun gear is drive-connected to the output shaft. A second planetary gear set allows for a technically simple output ratio of the power transmitted from the hybrid transmission to the differential shaft. In particular, an output ratio in the form of a second planetary gear set enables an advantageous, compact arrangement of the gear set around the differential shaft to form the output ratio. The functional scope of the hybrid transmission can be increased without significantly increasing the installation space required for the hybrid transmission.

[0021] In a further advantageous embodiment, only fixed gears are arranged on the countershaft. Alternatively, an idler gear of a second spur gear pair is arranged on the countershaft, with the gear of the first spur gear pair and the gear of the third spur gear pair being drive-connected to one another via the countershaft. This advantageous arrangement of the gears on the countershaft allows all gears arranged on the countershaft to be connected to one another in a rotationally fixed manner and to the output drive by engaging a single shift element.

[0022] In a further advantageous embodiment, the first spur gear pair and the third spur gear pair are connected to each other by a hollow shaft and arranged on the countershaft. Preferably, the countershaft is drivingly connected to the output shaft and the output, particularly preferably to a differential of the output, by means of a fourth spur gear pair and a fifth spur gear pair. In particular, in this embodiment, the hybrid transmission can be designed without a second spur gear pair, but with a fourth and fifth spur gear pair. This allows for the creation of an axially more compact hybrid transmission.

[0023] In a further advantageous embodiment, a planet gear carrier of the first planetary gear set is connected to the output shaft, wherein the sun gear of the first planetary gear set is connected to the second transmission input shaft and the ring gear of the first planetary gear set is connected to the first intermediate shaft. Alternatively, the planet gear carrier of the first planetary gear set is connected to the output shaft, wherein the ring gear of the first planetary gear set is connected to the second transmission input shaft and the sun gear of the first planetary gear set is connected to the first intermediate shaft. By connecting the sun gear to the second transmission input shaft and the ring gear to the first intermediate shaft, preferably only a small support torque needs to be applied by the first electric drive machine during electrodynamic starting and electrodynamic gear shifts.Furthermore, the first electric drive motor can operate as a generator for a longer period during electrodynamic starting, since generator operation can be maintained for longer as the driving speed increases. By connecting the ring gear to the second transmission input shaft and the sun gear to the first intermediate shaft, the first electric drive motor can operate at a low compensating speed during electrodynamic starting or electrodynamic gear shifting.

[0024] According to the invention, the second transmission input shaft, the first intermediate shaft, the second intermediate shaft, and the output shaft are arranged coaxially to one another. In addition, the first transmission input shaft, the second transmission input shaft, the first intermediate shaft, the second intermediate shaft, and the output shaft are designed as hollow shafts. Furthermore, the second transmission input shaft, the first intermediate shaft, and the second intermediate shaft surround the output shaft at least in sections. By designing the aforementioned shafts as hollow shafts and the coaxial arrangement, the compactness of the hybrid transmission can be further improved. In particular, the advantageous coaxial arrangement and the design of the shafts as hollow shafts enable the hybrid transmission to be arranged around the differential shaft, wherein the hybrid transmission and the differential shaft are arranged coaxially.

[0025] In a further advantageous embodiment, the first transmission input shaft comprises an internal combustion engine clutch for releasably and driveably connecting the first transmission input shaft to the internal combustion engine. It is understood that the internal combustion engine clutch can be designed as a dog-type shift element or a friction shift element. An internal combustion engine clutch allows the internal combustion engine to be completely decoupled from the hybrid transmission, thus enabling a highly efficient, purely 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.

[0026] In a further advantageous embodiment, a first shifting element is designed to drive-connect the first spur gear pair to the first intermediate shaft. Additionally or alternatively, a second shifting element is designed to drive-connect all gears arranged on the countershaft to the output. Further additionally or alternatively, a third shifting element is designed to drive-connect the second intermediate shaft to the first intermediate shaft. Additionally or alternatively, a fourth shifting element is designed to drive-connect the second intermediate shaft to the output shaft. Additionally or alternatively, a fifth shifting element is designed to drive-connect the first spur gear pair to the second transmission input shaft. Finally, further additionally or alternatively, a sixth shifting element is designed to block the first planetary gear set.This advantageous arrangement of the shifting elements allows the hybrid transmission to provide three hybrid gear ratios with multiple variants, one purely electric gear ratio, two electrodynamic and, in particular, continuously variable driving ranges, and at least one charge-to-neutral mode. A variable and compact hybrid transmission can be created that enables electrodynamic starting, electrodynamic gear shifts, and electromotive gear shifts. The aforementioned shifting operations allow a load to be maintained when a different gear ratio needs to be engaged for the combustion engine.

[0027] 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 all shifting elements, are designed as double-locking 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-locking element. In particular, a double-locking element can be switched using a single actuator.

[0028] In a further advantageous embodiment, the motor vehicle drive train preferably comprises a further electric machine which 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 internal combustion engine can be dispensed with since the first electric drive machine can tow the internal combustion engine.

[0029] 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 the serial driving mode, the electric drive motor is preferably operated as a generator by the internal combustion engine, and the energy thus generated is made available to the second electric drive motor. Preferably, the first electric drive motor and / or the additional electric machine can be controlled as a generator to supply the second electric drive motor in order to establish a serial driving mode. This makes it possible to create a highly variable motor vehicle drive train in which driving and, in particular, starting can be carried out electrically, even when the energy storage device is empty.

[0030] 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.

[0031] 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.

[0032] 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 gear, and / or a belt drive, in particular a traction drive.

[0033] 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.

[0034] 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.

[0035] 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.

[0036] A gear change 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.

[0037] 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.

[0038] 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.

[0039] 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.

[0040] 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.

[0041] 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.

[0042] In a so-called electromotive or output-assisted shift, tractive force is maintained preferably via an electric drive motor, which is connected to the output, in particular via a gear stage of the hybrid transmission. This allows some of the gear stages and shift elements of the hybrid transmission to be load-free, so that a shift element for a target gear stage can be engaged without loss of tractive force. 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. Consequently, an electric drive motor with a fixed gear ratio is connected to the output and supports the tractive force solely through an electric motor, while the combustion engine performs a load-free shift in the background, as in an automated manual transmission.

[0043] 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 a schematic representation of the hybrid transmission according to the invention; Fig. 3 schematically shows the switching states of the hybrid transmission according to the Fig. 2; Fig. 4 shows a further variant of a hybrid transmission according to the invention; Fig. 5 schematically shows the switching states of the hybrid transmission according to the Fig. 4; Fig. 6 shows a further variant of a hybrid transmission according to the invention; Fig. 7 schematically shows the switching states of the hybrid transmission according to the Fig. 6; Fig. 8 shows a further variant of a hybrid transmission according to the invention; Fig. 9 shows a further variant of a hybrid transmission according to the invention; Fig. 10 shows a further variant of a hybrid transmission according to the invention; Fig. 11 shows a further variant of a hybrid transmission according to the invention; Fig. 12 shows a further variant of a hybrid transmission according to the invention; Fig. 13 shows a further variant of a hybrid transmission according to the invention; and Fig. 14 shows a further variant of a hybrid transmission according to the invention.

[0044] 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.

[0045] Fig. 2 shows a variant of a hybrid transmission 18 according to the invention. The hybrid transmission 18 has a first transmission input shaft 24 and a second transmission input shaft 26, which are designed to transmit drive power of the drive machines into the hybrid transmission 18.

[0046] The hybrid transmission 18 further comprises an output shaft 28, a first intermediate shaft 30 and a second intermediate shaft 32. The aforementioned transmission shafts 24, 26, 28, 30, 32 are designed as hollow shafts. The hybrid transmission 18 also comprises a countershaft 34, a first planetary gear set RS1 and a second planetary gear set RS2. A total of three gear-forming spur gear pairs are arranged in the hybrid transmission 18, which are designated ST1 to ST3. For a better overview, the individual transmission shafts are additionally designated W0 to W7, and in Fig. 13 and Fig. 14 additionally with W8, numbered consecutively.

[0047] The hybrid transmission has six shift elements A to F.

[0048] The first transmission input shaft 24 has a torsional vibration damper and is drivingly connected to a crankshaft 36 of the internal combustion engine 16 (not shown) via the torsional vibration damper. The second transmission input shaft 26 is drivingly connected to the first electric drive motor 14 via a fixed gear and a chain.

[0049] The first transmission input shaft 24 is drive-connected, preferably by means of a chain, to a fixed gear arranged on the second intermediate shaft 32.

[0050] A sun gear of the first planetary gear set RS1 is drive-connected to the second transmission input shaft 26. A planet gear carrier of the first planetary gear set RS1 is drive-connected to the output shaft 28. A ring gear of the first planetary gear set RS1 is drive-connected to the first intermediate shaft 30. The connection of the second transmission input shaft 26 to the sun gear runs radially outward around the first planetary gear set RS1.

[0051] A ring gear of the second planetary gear set RS2 is fixed, i.e., connected to a component fixed to the housing, so that the ring gear of the second planetary gear set RS2 cannot rotate. A planetary gear carrier of the second planetary gear set RS2 is drive-connected to a differential of an output 38. A sun gear of the second planetary gear set RS2 is drive-connected to the output shaft 28.

[0052] A first spur gear pair ST1 has a fixed gear that is driveably connected to the countershaft 34 and arranged thereon. An idler gear of the first spur gear pair ST1 can be driveably connected to the first intermediate shaft 30 by engaging a first shift element A. By engaging a fifth shift element E, the idler gear of the first spur gear pair ST1 can be driveably connected to the second transmission input shaft 26.

[0053] In the example shown, the second spur gear pair ST2 comprises a fixed gear arranged on the countershaft 34 and a loose gear which can be connected to the output shaft 28 in a driving manner by engaging a second shift element B.

[0054] The third spur gear pair ST3 also includes a fixed gear arranged on the countershaft 34 and another fixed gear arranged on the second intermediate shaft 32. Also arranged on the second intermediate shaft 32 is a fixed gear that is drivingly connected to a fixed gear arranged on the first transmission input shaft 24, for example, via a chain or a gear chain.

[0055] By engaging a third switching element C, the second intermediate shaft 32 can be connected to the first intermediate shaft 30 in a driving manner.

[0056] By engaging a fourth shift element D, the second intermediate shaft 32 can be connected in a driving manner to the output shaft 28 and consequently to the planetary gear carrier of the first planetary gear set RS1.

[0057] By engaging a sixth shift element F, the first planetary gear set RS1 can be locked by drivingly connecting the sun gear of the first planetary gear set RS1 to the ring gear of the first planetary gear set RS1. It is understood that other locking variants are also conceivable in which two planetary gear set elements of the first planetary gear set RS1 are drivingly connected to one another. For example, the planetary gear carrier can be connected to the sun gear, or the planetary gear carrier can be connected to the ring gear of the first planetary gear set RS1.

[0058] The shift elements A to F are preferably designed as unsynchronized shift elements, for example, claw shift elements. Furthermore, the first shift element A and the third shift element C, the fourth shift element D and the second shift element B, as well as the sixth shift element F and the fifth shift element E are each combined to form a double shift element.

[0059] The hybrid transmission 18 or the motor vehicle drive train 12 comprises two planetary gear sets RS1, RS2, three spur gear pairs ST1, ST2, ST3, six shift elements A to F, three or four mechanical forward gear stages, which can preferably be used for the internal combustion engine 16 and / or the first electric drive motor 14, a purely electric forward gear stage and two EDA modes, as well as a first electric drive motor 14.

[0060] A particular advantage of the transmission structure of the disclosed hybrid transmission 18 is its simple technical design with only three spur gear pairs ST1 to ST3 and two planetary gear sets RS1, RS2. Furthermore, preferably only three actuators are required to control the hybrid transmission 18. The hybrid transmission 18 has a compact design, low component load, and low transmission losses. Furthermore, good gearing efficiency is achieved both in terms of the internal combustion engine and electrical transmission, as well as a good gear ratio range. Electrodynamic shifts, electromotive shifts, electrodynamic starting, and loading-into-neutral are possible. Furthermore, the arrangement of the transmission components allows the shift elements to be advantageously accessed with appropriate actuators.

[0061] It is understood that the differential of the output 38 can be designed as a ball differential or spur gear differential.

[0062] Furthermore, the hybrid transmission 18 can provide an axially parallel connection of the combustion engine 16 and the first electric drive motor 14, wherein the axially parallel connection can be provided via a chain or one or more spur gears.

[0063] In the Fig. 3 schematically shows the switching states of the hybrid transmission 18 according to the Fig. 2 in a switching matrix 40.

[0064] The first column of the shift matrix shows the hybrid gears H1 to H3, an electric gear E, two electrodynamic superposition states ECVT1, ECVT2, the charge-to-neutral state, and an additional hybrid gear ZH. The second to seventh columns show the shift states of shift elements A to F, where an "X" indicates that the respective shift element is closed, i.e., connecting the associated transmission components to each other 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.

[0065] The shift matrix 40 preferably describes the shift states for electrodynamic shifting; this is illustrated by an EDL positioned in front of the gear steps. If only the second shift element B or the fourth shift element D is engaged, the first electric drive motor 14 is decoupled.

[0066] The first hybrid gear stage H1 can be set by engaging the first shift element A and the fifth shift element E.

[0067] A first variant of the second hybrid gear stage H2.1 can be set up by closing the first switching element A and the second switching element B.

[0068] Closing the second switching element B and the fifth switching element E establishes a second variant of the second hybrid gear stage H2.2.

[0069] By closing the second switching element B and the third switching element C, a third variant of the second hybrid gear stage H2.3 can be set up.

[0070] A first variant of the third hybrid gear stage H3.1 can be set up by closing the third switching element C and the fourth switching element D.

[0071] Closing the fourth switching element D and the fifth switching element E sets up a second variant of the third hybrid gear stage H3.2.

[0072] A third variant of the third hybrid gear stage H3.3 can be set up by closing the fourth switching element D and the sixth switching element F.

[0073] An electric gear stage E can be set up by closing the sixth switching element F.

[0074] A first electrodynamic superposition state ECVT1 can be established by closing the first switching element A.

[0075] Closing the third switching element C establishes a second electrodynamic superposition state ECVT2.

[0076] The charge-in-neutral LiN state can be set by closing the fifth switching element E.

[0077] An additional hybrid gear stage can be established by closing the third switching element C and the fifth switching element E.

[0078] In Fig. 4 shows a further variant of a hybrid transmission 18 according to the invention. In contrast to the Fig. 2, the hybrid transmission 18 comprises the Fig. 4, a further electric machine 42, which can be designed in particular as a high-voltage starter generator. The further electric machine 42 is drivingly connected to the first transmission input shaft 24, for example via two meshing gears, a chain, or a gear chain. Furthermore, the hybrid transmission 18 according to Fig. 4 the hybrid transmission 18 according to the Fig. 2.

[0079] In Fig. 5 are the switching states of the hybrid transmission 18 according to the Fig. 4 in a switching matrix 44. The representation of the switching matrix 44 essentially corresponds to the representation of the switching matrix 40 according to the Fig. 3. In an embodiment with an additional electric motor 42, gear shifting is preferably performed by an electric motor. This is indicated in the shift matrix by an EMS placed in front of the respective hybrid gear. The additional electric motor 42 can support the synchronization of the internal combustion engine 16. It is understood that electrodynamic gear shifting is also possible as an alternative. If only the second shifting element B or the fourth shifting element D is engaged, the first electric drive motor 14 is decoupled.

[0080] A first hybrid gear stage H1 can be established by closing the first switching element A and the sixth switching element F.

[0081] Closing the first switching element A and the second switching element B establishes a first variant of the second hybrid gear stage H2.1.

[0082] Closing the second switching element B and the sixth switching element F can establish a second variant of the second hybrid gear stage H2.2.

[0083] A third variant of the second hybrid gear stage H2.3 can be set up by closing the second switching element B and the third switching element C.

[0084] By closing the third switching element C and the fourth switching element D, a first variant of the third hybrid gear stage H3.1 can be set up.

[0085] Closing the third switching element C and the sixth switching element F establishes a second variant of the third hybrid gear stage H3.2.

[0086] A third variant of the third hybrid gear stage H3.3 can be set up by closing the fourth switching element D and the sixth switching element F.

[0087] An electric gear stage E can be set up by closing the sixth switching element F.

[0088] A first electrodynamic superposition state ECVT1 can be established by closing the first switching element A.

[0089] Closing the third switching element C establishes a second electrodynamic superposition state ECVT2.

[0090] By closing the fifth switching element E, a charge-in-neutral LiN state can be established.

[0091] In other words, the electric gear stage, the two electrodynamic superposition states and the charge-in-neutral state are switched on analogously to the Fig. 3 shown switching matrix 40.

[0092] In Fig. 6 shows a further variant of a hybrid transmission 18 according to the invention. In contrast to the Fig. 4, the hybrid transmission 18 comprises the Fig. 6 an internal combustion engine clutch K0. In the example shown, the internal combustion engine clutch K0 is designed as a positive-locking switching element and can separate the first transmission input shaft 24 from the crankshaft 36 or connect the two to each other in a drivingly effective manner.

[0093] It is understood that the hybrid transmission 18 can, in principle, also be operated without an internal combustion engine clutch K0. However, for functional safety reasons, it may be advantageous to provide an internal combustion engine clutch K0.

[0094] In the example shown, the internal combustion engine clutch K0 separates the crankshaft 36 from the first transmission input shaft 24, whereby the connection between the further electric machine 42 and the first transmission input shaft 24 remains.

[0095] In Fig. 7, in a switching matrix 46 analogous to the switching matrices 44 and 40, the switching states of the hybrid transmission 18 are shown according to the Fig. 6. The shift matrix 46 is analogous to the shift matrix 44, with the shift states of the internal combustion engine clutch K0 also being included. The internal combustion engine clutch K0 is preferably engaged in every shift state, except for the shift state for the electric gear stage. In this state, the internal combustion engine clutch K0 can be open or closed. This is indicated in the shift matrix 46 by an "X" in parentheses.

[0096] For combustion engine or hybrid driving, three mechanical main gears are available for the combustion engine 16. The hybrid auxiliary gear stage ZH is a power-split gear. This means that the first planetary gear set RS1 functions as a summation gear. This is not the case in the first hybrid gear stage H1, the second hybrid gear stage H2, and the third hybrid gear stage H3.

[0097] The first hybrid gear stage H1 is established via the third spur gear pair and the first spur gear pair, with the first planetary gear set RS1 being interlocked. The second hybrid gear stage H2 is generated via the third spur gear pair ST3 and the second spur gear pair ST2. The third hybrid gear stage H3 runs directly from the second intermediate shaft 32 via the interlocked first planetary gear set RS1 to the output 38. Consequently, the third hybrid gear stage H3 is designed as a direct gear stage.

[0098] Electric driving is possible using the first electric drive motor 14. In the electric gear stage E, the sixth shift element F is engaged. Consequently, the first planetary gear set RS1 is locked. The first electric drive motor 14 thus delivers drive power to the output 38 via its own pre-transmission ratio and the transmission ratio via the second planetary gear set RS2. This allows for an electric vehicle drive for starting and driving both forwards and backwards.

[0099] If only the first shifting element A is closed, an EDA state arises, i.e. an electrodynamic superposition state ECVT1 on the first planetary gear set RS1. The internal combustion engine 16 is then connected to the ring gear of the first planetary gear set RS1 via the first spur gear pair ST1 and the third spur gear pair ST3, with the first electric drive motor 14 supporting the torque of the internal combustion engine 16 on the sun gear of the first planetary gear set RS1 and the planet gear carrier of the first planetary gear set RS1 being connected to the output 38 via an output gear set. This enables EDA forward starting. From the first electrical superposition state ECVT1, the first hybrid gear stage H1 and the first variant of the second hybrid gear stage H2.1 can be engaged for the internal combustion engine 16 both electromotively and electrodynamically, because the first shifting element A is closed in each of these shifting states.

[0100] A further electrodynamic superposition state ECVT2 is created by closing the third shift element C. The combustion engine 16 is then directly connected to the ring gear of the first planetary gear set RS1, with the first electric drive machine 14 supporting the torque of the combustion engine 16 on the sun gear of the first planetary gear set RS1 and the planet gear carrier of the first planetary gear set RS1 being connected to the output 38 via the output gear set. This enables a further EDA state forward. From the second electrodynamic superposition state ECVT2, the third variant of the second hybrid gear stage H2.3, the first variant of the third hybrid gear stage H3.1 and the additional hybrid gear stage ZH can be electrodynamically generated for the combustion engine 16, or the third variant of the second hybrid gear stage H2.3, the first variant of the third hybrid gear stage H3.1 and the second variant of the third hybrid gear stage H3.2 can be switched electromotively because the third switching element C is closed in each of these switching states.

[0101] An electrodynamic powershift from the first gear to the second gear can be carried out electrodynamically by the first electric drive motor 14, wherein the first shifting element A remains closed. In this case, a change is made electrodynamically from the first hybrid gear H1 to the first variant of the second hybrid gear H2.1. A shift from the second to the third gear can also be carried out electrodynamically by the first electric drive motor 14, wherein the third shifting element C remains closed. In this case, a change is made from the third variant of the second hybrid gear H2.3 to the first variant of the third hybrid gear H3.1. Optionally, a shift from the second gear to the additional hybrid gear can be carried out electrodynamically by the first electric drive motor 14, wherein the third shifting element C remains closed. In this case, a change is made from the third variant of the second hybrid gear H2.3 switched to the additional hybrid gear stage ZH.

[0102] Consequently, the first electrodynamic superposition state ECVT1 is preferentially used for starting and for electrodynamic powershifts from the first hybrid gear stage H1 to the first variant of the second hybrid gear stage H2.1. The second electrodynamic superposition state ECVT2 is consequently used for electrodynamic powershifts from the third variant of the second hybrid gear stage H2.3 to the first variant of the third hybrid gear stage H3.1 and optionally for electrodynamic shifts from the third variant of the second hybrid gear stage H2.3 to the additional hybrid gear stage ZH.

[0103] In the second gear, an electrodynamic preselective shift from the first variant of the second hybrid gear stage H2.1 to the third variant of the second hybrid gear stage H2.3 takes place for further shifting. The second variant of the second hybrid gear stage H2.2 is preferably used as the driving gear, particularly in electrodynamic shifting, since in this shifting state, a preferred speed level for the first electric drive motor 14 and a preferred high efficiency for the first electric drive motor 14 can be achieved.

[0104] An electrodynamic shift from the first hybrid gear stage H1 to the first variant of the second hybrid gear stage H2.1 can, for example, take place as follows. In the initial state, i.e. in the first hybrid gear stage H1, the first shift element A and the fifth shift element E are closed. The torques of the internal combustion engine 16 and the first electric drive motor 14 are adjusted such that, on the one hand, the desired output torque is provided and, on the other hand, the fifth claw shift element E to be disengaged is de-loaded. The fifth shift element E is then opened. The torques of the internal combustion engine 16 and the first electric drive motor 14 are adjusted such that, on the one hand, the desired output torque is provided and, on the other hand, a speed of the internal combustion engine 16 drops. If the second shift element B to be engaged is synchronous, it can be closed. This creates the first variant of the second hybrid gear stage H2.1 for the combustion engine 16 is switched mechanically, i.e. the first switching element A and the second switching element B are closed.

[0105] Downshifts occur analogously to upshifts, only in reverse order. It goes without saying that overrun shifts are also possible, since the first electric drive motor 14 can also provide braking support for torque on the first planetary gear set RS1.

[0106] The electrodynamic superposition states ECVT1, ECVT2 are power-split E-CVT driving ranges for the combustion engine 16, in which battery-neutral operation is also possible.

[0107] If only the fifth switching element E is closed, the first electric drive motor 14 can be connected to the internal combustion engine 16 independently of the output 38. The first electric drive motor 14 and the internal combustion engine 16 then rotate in a fixed relationship to one another. This makes it possible, on the one hand, to start the internal combustion engine 16 by means of 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, in particular in the charge-in-neutral LiN state, and charge the electrical energy storage device 22 or supply other electrical consumers. It is understood that a consumer can also be a second electric drive motor 20, which is arranged, for example, on the other vehicle axle and drives it in the form of an electric rear axle. Such a drive train is shown schematically in the Fig. 1 shown.

[0108] A transition from the charge-to-neutral LiN state is electrodynamically possible into the first hybrid gear H1, electrodynamically into the second variant of the second hybrid gear H2.2, electrodynamically into the second variant of the third hybrid gear H3.2, and electrodynamically into the additional hybrid gear ZH, since the fifth switching element is closed in each of these switching states. This allows the energy storage device 22 to be charged with high power when needed. In particular, with significantly higher power than is possible with the additional electric machine 42, which is designed in particular as a high-voltage starter generator. Especially at low temperatures, a high torque is required to start the internal combustion engine 16. The first electric drive motor 14 can be used for cold starting the internal combustion engine 16.Preferably, the first electric drive machine 14 can generate a significantly higher starting torque than the additional electric machine 42 designed as a high-voltage starter generator. The advantage here is that the additional electric machine 42 can be dimensioned smaller, since the additional electric machine 42 does not have to be designed for special cases, such as particularly low temperatures.

[0109] With the disclosed motor vehicle drive train 12, serial driving is possible, wherein the hybrid transmission 18 is switched to the charging-to-neutral LiN switching state, i.e., the fifth switching element E is closed. In this case, the first electric drive motor 14 can be operated as a generator and thus generate drive power for the second electric drive motor 20.

[0110] With a second purely electrically driven axle, as in Fig. 1, an all-wheel drive system can be created. For example, the hybrid transmission 18 with the internal combustion engine 16 and the first electric drive motor 14 can be arranged as a pure front-wheel drive in the motor vehicle 10, with additional rear-axle drive being provided by the separate second electric drive motor 20.

[0111] The second electric drive motor 20 can support the tractive force when shifts are necessary in the hybrid transmission 18, during which the output 38 of the hybrid transmission 18 becomes load-free. Examples of such transitions are: when the vehicle initially drives purely electrically using 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 using the first electric drive motor 14. This condition is particularly relevant for variants without an additional electric motor 42.

[0112] Another example is so-called serial shifting. When the fifth shift element E is closed, any desired electrodynamic shift occurs between the first hybrid gear stage H1, the second variant of the second hybrid gear stage H2.2, the second variant of the third hybrid gear stage H3.2, and the additional hybrid gear stage. The advantage of this is that the first electric drive motor 14 can operate continuously as a generator and thus supply both the on-board electrical system and the second electric drive motor 20 with electrical power.

[0113] In the case of electromotive load shifts, the tractive force is supported during shifts for the internal combustion engine 16. The first electric drive motor 14 can maintain the tractive force via its drive gear, i.e. electric gear stage E, in which the sixth shift element F is closed, when a change occurs in the first shift element A, second shift element B, third shift element C and / or fourth shift element D.

[0114] For example, an electromotive load shift from the first hybrid gear stage to the second variant of the second hybrid gear stage H2.2 in the hybrid transmission can take place as follows. It goes without saying that this sequence also applies to variants without an internal combustion engine clutch K0. In the first hybrid gear stage H1, the internal combustion engine clutch K0 is closed, if present. In addition, the first shifting element A and the sixth shifting element F are closed. A load reduction takes place on the first shifting element A and a simultaneous load build-up on the first electric drive machine 14. The load reduction can take place when the internal combustion engine 16 and the further electric machine 42 reduce the torque or when the further electric machine 42 compensates for the torque of the internal combustion engine 16 in a generator manner, so that the sum of the torques of the internal combustion engine 16 and the further electric machine 42 is essentially zero.The first switching element A is opened. The speed of the internal combustion engine 16 and the additional electric machine 42 is reduced, so that the second switching element D becomes synchronous. For this purpose, the additional electric machine 42 can, for example, operate as a generator, which is preferred. Alternatively, the internal combustion engine 16 can enter overrun mode. The second switching element B can then be engaged.

[0115] The following functions can be covered by the additional electric machine 42, preferably a high-voltage starter generator. It goes without saying that these functions also apply to variants with and without the internal combustion engine clutch K0. The internal combustion engine 16 can be started from purely electric drive. A supply to the on-board electrical system can be ensured. Serial crawling and driving both forwards and backwards can be enabled. The speed control of the internal combustion engine 16 can be supported during coupling and gear changes. The internal combustion engine 16 can be coupled by electric motor into the first hybrid gear H1, the second variant of the second hybrid gear H2.2, the second variant of the third hybrid gear H3.2 and the third variant of the third hybrid gear H3.3 when the first electric drive machine 14 is traveling in the electric gear E.The additional electric machine 42 can assist in relieving the load on the first shifting element A, the second shifting element B, the third shifting element C, and the fourth shifting element D by operating as a generator. The energy thus generated can be used by the first electric drive motor 14 to assist traction.

[0116] In Fig. 8 shows a further variant of a hybrid transmission 18 according to the invention. In contrast to the Fig. 2, the connection to the first planetary gear set RS1 changes, whereby the connections per se for the planetary gear set elements of the first planetary gear set RS1, i.e. for the sun gear, the planetary gear carrier and the ring gear, remain identical. In the embodiment shown, the first electric drive motor 14 is connected to the sun gear of the first planetary gear set RS1 via a pot. In other words, the second transmission input shaft 26 runs radially outward past the first planetary gear set RS1. The output shaft 28 is directly connected to the planetary gear carrier or web. Consequently, the ring gear of the first planetary gear set RS1 is driven from the side facing away from the output 38 and not, as in Fig. 2, connected from the side facing the output 38.

[0117] In Fig. 9 shows a further variant of a hybrid transmission 18 according to the invention. In contrast to the Fig. In the embodiment shown in Figure 8, the connections to the first planetary gear set RS1 change. In the embodiment shown, the ring gear of the first planetary gear set RS1 is drivingly connected to the second transmission input shaft 26, and the sun gear of the first planetary gear set RS1 is drivingly connected to the first intermediate shaft 30. The output shaft 28 is connected to the planetary gear carrier. Consequently, the first electric drive motor 14 is connected to the ring gear, and the gears of the internal combustion engine 16 are connected to the sun gear. As a result, the first electric drive motor 14 on the ring gear of the first planetary gear set RS1 can be operated at a lower compensating speed during electrodynamic starting or electrodynamic gear shifting. The disadvantage here is that the first electric drive motor 14 is operated with a higher support torque.Furthermore, the first electric drive machine 14 can be operated as a generator for a shorter period during electrodynamic starting, since the generator operation is abandoned earlier with increasing driving speed than when the first electric drive machine 14 is connected to the sun gear of the first planetary gear set RS1.

[0118] In Fig. 10 shows a further variant of a hybrid transmission 18 according to the invention. In contrast to the Fig. In the embodiment shown in Figure 6, the internal combustion engine clutch K0 is designed as a friction-engaging switching element. This allows, in particular, a so-called drag or momentum start of the internal combustion engine 16 to occur, in which the internal combustion engine clutch K0 is operated in a slipping manner and can thus crank the internal combustion engine 16.

[0119] In Fig. 11 shows a further variant of a hybrid transmission 18 according to the invention. In contrast to the Fig. In the embodiment shown in Figure 2, the second spur gear pair ST2 comprises a fixed gear that is drivingly connected to the output shaft 28 and arranged thereon. Furthermore, the second spur gear pair ST2 comprises an idler gear that is arranged on the countershaft 34. As a result, the second shifting element B is arranged on the countershaft 34. Consequently, the double shifting element comprising the fourth shifting element D and the second shifting element B can be designed with a distributed shift fork, since the fourth shifting element D is arranged on the output shaft 28. However, the second shifting element B and the fourth shifting element D can still be controlled by a single actuator.

[0120] The second shift element B can be nested with the connection plane of the first transmission input shaft 24 to the second intermediate shaft 32. This allows the axial length of the overall system, i.e., the hybrid transmission 18 or the motor vehicle drive train 12, to be reduced.

[0121] In Fig. 12 shows a further variant of a hybrid transmission 18 according to the invention. In contrast to the Fig. In the embodiment shown in Figure 2, the first electric drive motor 14 is designed as a coaxial motor rather than an axially parallel drive motor and is arranged coaxially with the output shaft 28 and the differential shaft. In the example shown, the second transmission input shaft 26 comprises an output shaft of the first electric drive motor 14.

[0122] Within the first electric drive machine 14 or a rotor of the first electric drive machine 14, the first planetary gear set RS1, the second planetary gear set RS2, the differential of the output 38 and / or the double shifting element comprising the sixth shifting element F and the fifth shifting element E can be radially nested at least in sections. This means that the first electric drive machine 14 surrounds the aforementioned transmission components at least in sections radially and axially. It is understood that an embodiment with an internal combustion engine clutch K0 and a further electric drive machine 42, as well as the various disclosed idler gear variants, can each also be combined with a coaxially arranged first electric drive machine 14.

[0123] In Fig. 13 shows a further variant of a hybrid transmission 18 according to the invention. In contrast to the Fig. 2, the hybrid transmission 18 is according to the Fig. 13 without a second spur gear pair ST2. Furthermore, the hybrid transmission 18 according to the Fig. 13 a fourth spur gear pair ST4 and a fifth spur gear pair ST5, wherein the output shaft 28 is drive-effectively connected to the countershaft 34 by means of the fourth spur gear pair ST4, and the countershaft 34 is drive-effectively connected to a differential of the output 38 by means of the fifth spur gear pair ST5. Furthermore, a hollow shaft is arranged on the countershaft 34, which comprises a fixed gear of each of the first spur gear pair ST1 and the third spur gear pair ST3. This hollow shaft can be drive-effectively connected to the countershaft 34 by engaging the second shifting element B. Consequently, as already described above, the double shifting element comprising the fourth shifting element D and the second shifting element B is designed with a distributed shift fork. In the example shown, the fourth spur gear pair ST4 is arranged in a gear set plane between the first planetary gear set RS1 and a connection plane of the first electric drive motor 14.Furthermore, the hybrid transmission 18 according to the . Fig. 13 does not have a second planetary gear set RS2, since the connection to the output 38 is made by means of the countershaft 34 and the fourth spur gear pair ST4 and the fifth spur gear pair ST5.

[0124] In Fig. 14 shows a further variant of a hybrid transmission 18 according to the invention. In contrast to the Fig. In the embodiment shown in Figure 13, the fourth spur gear pair ST4 is arranged at a first end of the transmission, with the output 38 being arranged at the other end of the transmission. The connections and arrangements of the remaining transmission components correspond to the embodiment according to Fig. 13.

[0125] 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.

[0126] 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.A computer program can be stored / distributed on a non-volatile storage medium, for example, on an optical storage device or on a solid-state drive (SSD). A computer program can be distributed together with hardware and / or as part of hardware, for example, via the Internet or via wired or wireless communication systems. Reference signs in the claims are not to be understood as limiting. 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 units 24 first transmission input shaft 26 second transmission input shaft 28 Output shaft 30 first intermediate shaft 32 second intermediate shaft 34 Countershaft 36 Crankshaft 38 downforce 40 switching matrix 42 additional electric machines 44 Switch matrix 46 Switch matrix AF switching elements K0 internal combustion engine clutch RS1 first planetary gear set RS2 second planetary gear set ST1-ST5 spur gear pairs W0-W8 additional designation for gear shafts

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 (10); a second transmission input shaft (26) for operatively connecting the hybrid transmission (18) to a first electric drive motor (14) of the motor vehicle (10); a first intermediate shaft (30); a second intermediate shaft (32) which is drivingly connected to the first transmission input shaft (24); an output shaft (28) for operatively connecting the hybrid transmission (18) to an output (38); a first planetary gear set (RS1) connected to the second transmission input shaft (26), the first intermediate shaft (30) and the output shaft (28); a countershaft (34); spur gear pairs (ST1, ST2, ST3, ST4, ST5) arranged in several gear set levels; and several gearshift devices with shift elements (A, B, C, D, E, F) for engaging gear steps, wherein a gear of a first spur gear pair (ST1) and a gear of a third spur gear pair (ST3) are drivingly connected to one another; the second intermediate shaft (32) and another gear of the third spur gear pair (ST3) are drivingly connected to one another; the second intermediate shaft (32) and another gear of the third spur gear pair (ST3); the second transmission input shaft (26), the first intermediate shaft (30), the second intermediate shaft (32) and the output shaft (28) are arranged coaxially to one another; the first transmission input shaft (24), the second transmission input shaft (26), the first intermediate shaft (30), the second intermediate shaft (32) and the output shaft (28) are designed as hollow shafts; and the second transmission input shaft (26), the first intermediate shaft (30) and the second intermediate shaft (32) surround the output shaft (28) at least in sections. [2] Hybrid transmission (18) according to claim 1, wherein a differential of the output (38) comprises a differential shaft which is designed as a solid shaft and is surrounded at least in sections by the output shaft (28); and an axial length of the differential shaft is greater than an axial length of the output shaft (28) and the differential shaft completely penetrates the output shaft (28). [3] Hybrid transmission (18) according to one of the preceding claims, wherein the hybrid transmission comprises a second planetary gear set (RS2) which is drivingly connected to the output shaft (28) and a differential of the output (38). [4] Hybrid transmission (18) according to one of the preceding claims, wherein exclusively fixed gears are arranged on the countershaft (34); or a loose gear of a second spur gear pair (ST2) is arranged on the countershaft (34), and the gear of the first spur gear pair (ST1) and the gear of the third spur gear pair (ST3) are drivingly connected to one another by means of the countershaft (34). [5] Hybrid transmission (18) according to one of claims 1 or 2, wherein the first spur gear pair (ST1) and the third spur gear pair (ST3) are connected to one another by means of a hollow shaft and are arranged on the countershaft (34). [6] Hybrid transmission (18) according to one of the preceding claims, wherein a planetary gear carrier of the first planetary gear set (RS1) is connected to the output shaft (28); the sun gear of the first planetary gear set (RS1) is connected to the second transmission input shaft (26) and the ring gear of the first planetary gear set (RS1) is connected to the first intermediate shaft (30); or the ring gear of the first planetary gear set (RS1) is connected to the second transmission input shaft (26) and the sun gear of the first planetary gear set (RS1) is connected to the first intermediate shaft (30). [7] Hybrid transmission (18) according to one of the preceding claims, wherein the first transmission input shaft (24) comprises an internal combustion engine clutch (K0) for releasably drivingly connecting the first transmission input shaft (24) to the internal combustion engine (16). [8] Hybrid transmission (18) according to one of the preceding claims, wherein a first switching element (A) is designed to drive-effectively connect the first spur gear pair (ST1) to the first intermediate shaft (30); a second switching element (B) is designed to drive-effectively connect all gearwheels arranged on the countershaft (34) to the output (38); a third switching element (C) is designed to drive-connect the second intermediate shaft (32) to the first intermediate shaft (30); a fourth switching element (D) is designed to drive-effectively connect the second intermediate shaft (32) to the output shaft (28); a fifth shift element (E) is designed to drive-connect the first spur gear pair to the second transmission input shaft (26); and / or a sixth shift element (F) is designed to block the first planetary gear set (RS1). [9] 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 are designed as double switching elements and can be actuated by a double-acting actuator. [10] 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). [11] Motor vehicle drive train (12) according to claim 10, wherein the first electric drive machine (14) 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). [12] Motor vehicle drive train (12) according to claim 10 or 11, wherein an output (38) 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). [13] Method for operating a motor vehicle drive train (12) according to one of claims 10 to 12. [14] Method according to the preceding claim, wherein switching is carried out electrodynamically. [15] Motor vehicle (10) with: a motor vehicle drive train (12) according to one of claims 10 to 12; 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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