Compact hybrid powertrain

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 (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 third transmission input shaft (28) for connecting the hybrid transmission (18) with a second electric drive motor (20) of the motor vehicle (10); a planetary gear set (RS) which is connected to the first transmission input shaft (24) and the third transmission input shaft (28) and can be connected to the second transmission input shaft (26); a first intermediate shaft (30) which is effectively connected to an output (34) of the hybrid transmission (18); spur gear pairs (ST1, ST2, ST3, ST4, ST5) arranged in several gear set levels to form gear stages; and several gearshift devices with switching elements (A, B, C, D, E, F, G) for engaging the gear stages; wherein at least one purely electric electrodynamic superposition state (eECVT1) for purely electric starting and / or for purely electric load switching can be set up by means of the planetary gear set (RS); and wherein the first transmission input shaft (24), the second transmission input shaft (26) and the third transmission input shaft (28) are arranged coaxially to each other; the first transmission input shaft (24) is designed as a solid shaft; the second transmission input shaft (26) and the third transmission input shaft (28) are designed as hollow shafts; the third transmission input shaft (28) surrounds the first transmission input shaft (24) at least partially; and / or the second transmission input shaft (26) surrounds the third transmission input shaft (28) at least partially.

Description

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

[0002] Vehicles are increasingly being equipped with hybrid drives, meaning they have at least two different drive sources. Hybrid drives can contribute to reducing fuel consumption and pollutant emissions. Powertrains with an internal combustion engine and one or more electric motors, configured as parallel hybrids or mixed hybrids, have largely become the standard. In such hybrid drives, the internal combustion engine and the electric motor are arranged in a largely parallel power flow. This allows for both a superposition of the drive torques and control via either the internal combustion engine or the electric motor. Since the drive torques of the electric motor and the internal combustion engine can add up depending on the control configuration, a comparatively smaller internal combustion engine and / or its temporary deactivation are possible.This allows for a significant reduction in CO2 emissions without any noticeable 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] One disadvantage of the aforementioned hybrid drives is their generally more complex design, as both drive sources preferably transmit power to a single drive shaft via a single transmission. This makes such transmissions typically complex and expensive to produce. Reducing the complexity of a hybrid transmission's design usually comes at the cost of reduced versatility.

[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 part of the transmission can be simplified, such as by eliminating the reverse gear, and at least one electric motor is used 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 then becomes part of the transmission.

[0006] The patent application DE 10 2013 215 114 A1 relates to a hybrid drive for a motor vehicle, comprising an internal combustion engine with a drive shaft, an electric machine with a rotor that can be operated as a motor and as a generator, an automated transmission designed in a reduction gear with an input shaft and at least one output shaft, and a planetary gear unit with two input elements and one output element.In this hybrid drive, the superimposed transmission is arranged coaxially over a free end of the output shaft, and the first input element of the superimposed transmission is connected in a rotationally fixed manner to a hollow shaft arranged coaxially over the output shaft, which can be connected in a rotationally fixed manner to a loose gear of the immediately axially adjacent spur gear stage of the 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 superimposed transmission via a bridging switching element for bypassing the superimposed transmission, the second input element of the superimposed transmission is permanently in drive connection with the rotor of the electric machine, and the output element of the superimposed transmission is connected in a rotationally fixed manner to the output shaft.

[0007] Another hybrid drive is known from the pre-published patent application DE 10 2021 205 940 A1.

[0008] Against this background, the task for an expert is to create a hybrid transmission with a compact design. In particular, a hybrid transmission should be created that enables electrodynamic starting and electrodynamic shifting.

[0009] The above problem is solved by a hybrid transmission for a motor vehicle powertrain, comprising: a first transmission input shaft for connecting the hybrid transmission to an internal combustion engine of the motor vehicle; a second transmission input shaft for connecting the hybrid transmission to a first electric drive motor of the motor vehicle; a third transmission input shaft for connecting the hybrid transmission to a second electric drive motor of the motor vehicle; a planetary gear set that is connected to the first transmission input shaft and the third transmission input shaft and can be connected to the second transmission input shaft; a first intermediate shaft which is effectively connected to an output of the hybrid transmission; Spur gear pairs arranged in several gear set planes to form gear stages; and several gearshift devices with switching elements for engaging the gear stages; wherein by means of the planetary gear set, at least one purely electrical electrodynamic superposition state can be established for purely electric starting and / or for purely electric load switching; and wherein the first transmission input shaft, the second transmission input shaft and the third transmission input shaft are arranged coaxially to each other; the first transmission input shaft is designed as a solid shaft; the second transmission input shaft and the third transmission input shaft are designed as hollow shafts; the third transmission input shaft surrounds the first transmission input shaft at least partially; and / or the second transmission input shaft surrounds the third transmission input shaft at least partially.

[0010] The above task is further solved by a motor vehicle powertrain for a motor vehicle, comprising: a hybrid transmission as previously defined; an internal combustion engine that can be connected to the first transmission input shaft; a first electric drive motor which is effectively connected to the second transmission input shaft; and a second electric drive motor, which is effectively connected to the third gearbox input shaft.

[0011] Furthermore, the above problem is solved by a method for operating a motor vehicle powertrain as defined above.

[0012] Finally, the above task is solved by a motor vehicle equipped with: a motor vehicle powertrain as previously defined; and an energy storage device for storing energy to supply the first electric drive motor and / or the second electric drive motor.

[0013] 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 combinations specified, but also in other combinations or individually, without departing from the scope of the present invention. In particular, the motor vehicle powertrain, the motor vehicle, and the method can be implemented according to the embodiments described for the hybrid transmission in the dependent claims.

[0014] A compact hybrid transmission can be easily created by using a first input shaft to connect the hybrid transmission to an internal combustion engine and a second input shaft to connect the hybrid transmission to an electric drive motor. The connection can be either switchable or non-switchable. A planetary gear set, connected to the first and third input shafts and also connectable to the second input shaft, allows for at least two electrodynamic superposition states as well as a purely electric electrodynamic superposition state. This enables a compact hybrid transmission capable of charging-to-neutral, electrodynamic starting, and electrodynamic shifting. A purely electric electrodynamic superposition state allows for purely electric starting.Furthermore, purely electric load switching is possible. A hybrid transmission with increased driving comfort during purely electric driving can be created. In particular, the hybrid transmission can provide at least two mechanical forward gears for the combustion engine and two electric gears for the first electric drive motor. A planetary gear set enables an axially and / or radially compact hybrid transmission with a high degree of functionality. Preferably, the combustion gears and the electric gears for the first electric drive motor can be configured by engaging only one switching element each.

[0015] In an advantageous embodiment, the third transmission input shaft is designed without switching elements. This allows the drive power of the second electric drive motor to be introduced into the hybrid transmission with high efficiency. Furthermore, the advantageous arrangement of the switching elements improves their accessibility.

[0016] In a further advantageous embodiment, the hybrid transmission comprises a second countershaft that is effectively connected to the output of the hybrid transmission. The use of two countershafts further improves the axial compactness of the hybrid transmission. In particular, it is possible to establish so-called double gear planes by means of two countershafts, in which a fixed gear on a transmission input shaft meshes with a loose gear on the first countershaft and a loose gear on the second countershaft.

[0017] In a further advantageous embodiment, the first, second, and / or third transmission input shafts feature a double gear plane. This allows at least two selectable gear ratios to be achieved using three gears. A compact, space-efficient, and weight-optimized hybrid transmission can thus be created.

[0018] According to the invention, the first, second, and third transmission input shafts are arranged coaxially with each other. This further improves the compactness of the hybrid transmission. Furthermore, the shafts can be advantageously supported. According to the invention, the first transmission input shaft is designed as a solid shaft. This allows for a cost-effective and robust first transmission input shaft. According to the invention, the second and third transmission input shafts are designed as hollow shafts. This allows the transmission shafts to be advantageously arranged around each other, at least partially. The compactness of the hybrid transmission can be increased. According to the invention, the third transmission input shaft surrounds the first transmission input shaft, at least partially. This further increases the compactness of the hybrid transmission.Finally, the second transmission input shaft also surrounds the third transmission input shaft, at least partially, either additionally or alternatively. This further increases the compactness of the hybrid transmission. In particular, the axial compactness of the hybrid transmission can be increased by the coaxial arrangement of the transmission input shafts and their at least partial surround.

[0019] In a further advantageous embodiment, the hybrid transmission comprises exactly four or exactly five gear-forming spur gear pairs and a planetary gear set for forming the gear stages. By using exactly four or exactly five spur gear pairs with a planetary gear set, a compact hybrid transmission with few gear meshes can be created. This allows for a compact transmission with a high range of functions and, in particular, high efficiency.

[0020] In a further advantageous embodiment, the hybrid transmission features an internal combustion engine clutch for the detachable, drive-effective connection of the first transmission input shaft to the internal combustion engine, the clutch preferably being arranged on the first transmission input shaft. It is understood that the internal combustion engine clutch can be designed as a dog clutch or a friction clutch. An internal combustion engine clutch allows the internal combustion engine to be decoupled from the hybrid transmission, thus enabling a highly efficient, purely electric driving mode via 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 increases the variability and efficiency of the hybrid transmission.Furthermore, for functional safety reasons, an internal combustion engine clutch can be used in a hybrid transmission.

[0021] In a further advantageous embodiment, the first transmission input shaft is effectively connected to a planet carrier of the planetary gear set. Additionally or alternatively, the second transmission input shaft is effectively connected to a ring gear of the planetary gear set. Finally, additionally or alternatively, the third transmission input shaft is effectively connected to a sun gear of the planetary gear set. This allows for an advantageous transmission of the drive power from the first electric drive motor via the planetary gear set. Furthermore, the aforementioned connections advantageously establish at least two electrodynamic superposition states and one purely electrical electrodynamic superposition state.In particular, the connection enables a first electrodynamic superposition state for low speeds and a second electrodynamic superposition state for higher speeds. It is understood that further electrodynamic superposition states can be established.

[0022] In a further advantageous embodiment, a first switching element is configured to effectively connect the second transmission input shaft to the countershaft by means of a first pair of spur gears. Additionally or alternatively, a second switching element is configured to effectively connect the second transmission input shaft to the countershaft by means of a second pair of spur gears. Furthermore, additionally or alternatively, a third switching element is preferably configured to effectively connect the first or third transmission input shaft to the countershaft by means of a third pair of spur gears. Additionally or alternatively, a fourth switching element is configured to effectively connect the first or third transmission input shaft to the countershaft by means of a fourth pair of spur gears.Furthermore, a fifth switching element is provided to connect the first transmission input shaft to the countershaft via the third spur gear pair or a fifth spur gear pair. A sixth switching element is provided to lock the planetary gear set. Finally, a seventh switching element is provided to connect the first transmission input shaft to the second transmission input shaft. It is understood that a connection to the countershaft includes a connection to the first countershaft or the second countershaft if two countershafts are present in the transmission. If the transmission includes only one countershaft, the connection to that countershaft is meant.This advantageous arrangement of the switching elements allows the hybrid transmission to operate in up to four electrodynamic superposition states and one purely electric electrodynamic superposition state. Furthermore, at least two mechanical gear stages can be configured for each of the drive motors. It is understood that locking a planetary gear set is achieved by connecting any two of the three elements of the planetary gear set to provide drive power. In particular, a sun gear can be connected to a planet carrier, a sun gear to a ring gear, or a planet carrier to a ring gear.

[0023] In a further advantageous embodiment, the switching elements are designed as positive-locking switching elements. Additionally or alternatively, at least two of the switching elements, preferably all switching elements, are designed as double switching elements and can be actuated by a double-acting actuator. Positive-locking switching elements enable a highly efficient and cost-effective hybrid transmission. The technical design and operation of the hybrid transmission can be further simplified by using a double switching element. In particular, a double switching element can be switched by means of a single actuator.

[0024] In an advantageous embodiment, the second electric drive motor is designed as a high-voltage starter-generator and is preferably arranged parallel to the axis of the third transmission input shaft. By using a second electric drive motor designed as a high-voltage starter-generator, the installation space required and the weight of the drive train can be further reduced. Parallel mounting of the second electric drive motor enables an axially compact drive train.

[0025] In a further advantageous embodiment, the first electric drive motor is designed as a coaxial motor. Additionally, the planetary gear set and / or a double switching element comprising two switching elements for engaging the gear stages are arranged axially and / or radially, at least partially, within the first electric drive motor. This further improves the axial compactness of the drive train. In particular, a space-efficient drive train can be created. Specifically, a coaxial motor allows the first electric drive motor to be directly connected to the second transmission input shaft, thus eliminating the need for additional connecting elements such as gears or a traction drive. This results in a highly efficient and weight-optimized drive train.

[0026] 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 to a static component, such as a frame and / or a gearbox housing, in a rotationally fixed manner by means of a locking element. It is also conceivable to brake the element until it comes to a standstill.

[0027] A planetary gear set is locked together by connecting two gears and / or the planet carrier and a gear of the planetary gear set in a way that provides a driving force, so that they rotate together at the same speed around the same point, preferably the center of the planetary gear set. When two gears and / or a planet carrier and a gear of the planetary gear set are locked together, the planetary gear set preferably acts like a shaft; in particular, no gear ratio is achieved within the planetary gear set.

[0028] In this context, "drive-effective connection" refers specifically to a non-switchable connection between two components, designed for the permanent transmission of rotational speed, torque, and / or drive power. This connection can be direct or via a fixed gear ratio. Examples of such connections include a fixed shaft, a gear, particularly a spur gear, and / or a drive element, especially a traction drive.

[0029] In this context, the terms "connectable for drive purposes," "can be connected for drive purposes," or "is designed for drive-effective connection" are understood to refer specifically to a switchable connection between two components which, in a closed state, is intended for the temporary transmission of rotational speed, torque, and / or drive power. In an open state, the switchable connection preferably transmits essentially no rotational speed, torque, and / or drive power, at least temporarily.

[0030] Stationary charging or charging-in-neutral refers in particular to operating the electric drive motor as a generator, preferably when stationary with the combustion engine running, in order to charge an energy storage device and / or to power on-board electronics.

[0031] In this context, an actuator is in particular a component that converts an electrical signal into a mechanical movement. Preferably, actuators used with dual switching elements perform movements in two opposite directions, in order to switch one switching element of the dual switching element in the first direction and to switch the other switching element in the second direction.

[0032] A gear change is achieved, in particular, by disengaging a shift element and / or clutch and simultaneously engaging the shift element and / or clutch for the next higher or lower gear. The second shift element and / or clutch thus gradually takes over the torque from the first shift element and / or clutch until, at the end of the gear change, the entire torque is being handled by the second shift element and / or clutch. With prior synchronization, a gear change can be performed more quickly; preferably, positive-locking shift elements can be used for this purpose.

[0033] An internal combustion engine can be any machine that can generate rotary motion by burning a fuel such as gasoline, diesel, kerosene, ethanol, liquefied petroleum gas (LPG), or autogas. Examples of internal combustion engines include gasoline engines, diesel engines, Wankel engines, and two-stroke engines.

[0034] In serial driving or creep mode, an electric motor of a vehicle is driven as a generator by an internal combustion engine of the same vehicle. The energy generated in this way is then supplied to another electric motor of the vehicle to provide propulsion power.

[0035] An electrodynamic starting element (EDA) uses one or more planetary gear sets to superimpose the speeds of the combustion engine and the electric drive motor, enabling a vehicle to start from a standstill with the combustion engine running, preferably without a friction clutch. The electric drive motor provides torque support. Preferably, the combustion engine can no longer be disconnected from the transmission by a starting clutch or similar device. Using an EDA preferably eliminates the need for a starter, generator, and starting clutch or hydrodynamic torque converter. In particular, an EDA is designed to be so compact that all components fit within the standard clutch housing without extending the transmission.The electrodynamic starting element can be rigidly connected to an internal combustion engine, and in particular to the flywheel of an internal combustion engine, via a softly tuned torsional damper. This allows the electric drive and the internal combustion engine to be operated either simultaneously or alternatively. When the vehicle comes to a stop, both the electric drive and the internal combustion engine can be switched off. Due to the precise controllability of the electric drive, a very high level of starting performance is achieved, comparable to that of a drive with a torque converter.

[0036] In a so-called electrodynamic shift (EDS), as with EDA starting, the speeds of the combustion engine and the electric drive motor are 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 engaged is unloaded. After this shift element opens, the speed is adjusted while maintaining the tractive force, so that the shift element to be engaged becomes synchronous. After the shift element closes, the load distribution between the combustion engine and the electric drive motor occurs as desired, depending on the hybrid operating strategy.The electrodynamic shifting method has the advantage that the shift element to be selected for the target gear is synchronized by 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 EDS shifting method is that high tractive force can be achieved, since the torques of the combustion engine and the electric motor combine in the hybrid transmission.

[0037] The invention is described and explained in more detail below with reference to some selected embodiments in conjunction with the accompanying drawings. These show: Fig. 1 a schematic top 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. Schematic representation of the switching states of the hybrid transmission according to Fig. 2; Fig. 4 another variant of a hybrid transmission according to the invention; Fig. 5 a schematically simplified representation of a hybrid transmission; Fig. 6 schematically the switching states of the hybrid transmission according to Fig. 4; Fig. 7 another variant of a hybrid transmission according to the invention; Fig. 8 another variant of a hybrid transmission according to the invention; Fig. 9 a schematically simplified representation of a hybrid transmission; Fig. 10 schematically the switching states of the hybrid transmissions according to the Fig. 7 and Fig. 8; and Fig. 11 another variant of a hybrid transmission according to the invention.

[0038] In Fig. Figure 1 schematically shows a motor vehicle 10 with a motor vehicle powertrain 12. The motor vehicle powertrain 12 comprises 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 powertrain 12 also includes a second electric drive motor 20, which is connected to the hybrid transmission 18 of the motor vehicle 10. It is understood that the hybrid transmission 18 can also be connected to the rear axle of the motor vehicle 10. The motor vehicle powertrain 12 supplies drive power from the first electric drive motor 14, the internal combustion engine 16, and / or the optional second electric drive motor 20 to the wheels of the motor vehicle 10.The motor vehicle 10 also has an energy storage device 22 to store energy for supplying the first electric drive motor 14 and / or the second electric drive motor 20.

[0039] Fig. Figure 2 shows a schematic representation of a hybrid transmission 18 according to the invention. The hybrid transmission 18 has a first transmission input shaft 24, a second transmission input shaft 26 and a third transmission input shaft 28, which are designed to transmit drive power from the drive machines 14, 16, 20 into the hybrid transmission 18.

[0040] Furthermore, the hybrid transmission 18 includes a planetary gear set RS and five spur gear pairs, designated ST1 to ST5.

[0041] Furthermore, the hybrid transmission 18 comprises a first countershaft 30 and a second countershaft 32, each of which is connected to an output 34 of the hybrid transmission 18 via an output gear.

[0042] The first spur gear pair ST1 comprises a loose gear arranged on the first countershaft 30, which meshes with a fixed gear arranged on the second transmission input shaft 26. This fixed gear arranged on the second transmission input shaft 26 is also part of the second spur gear pair ST2, which comprises a loose gear arranged on the second countershaft 32, which meshes with the fixed gear arranged on the second transmission input shaft 26. The first spur gear pair ST1 and the second spur gear pair ST2 thus form a double gear plane.

[0043] The third spur gear pair ST3 comprises a loose gear arranged on the first countershaft 30, which meshes with a fixed gear arranged on the first transmission input shaft 24. The fixed gear arranged on the first transmission input shaft 24 is also part of the fourth spur gear pair ST4 and meshes with a loose gear arranged on the second countershaft 32.

[0044] The fifth spur gear pair ST5 comprises a loose gear arranged on the first transmission input shaft 24, which meshes with a fixed gear arranged on the second countershaft 32. The fifth spur gear pair ST5 is preferably used to establish the purely electrical electrodynamic superposition state.

[0045] The second electric drive motor 20 is effectively connected via a traction gear to a fixed gear arranged on the third transmission input shaft 28. The second electric drive motor 20 is arranged axially parallel to the hybrid transmission 18.

[0046] The first electric drive machine 14 is designed as a coaxial machine, wherein the planetary gear set RS and a double switching element are arranged at least sectionally radially and / or axially within the first electric drive machine 14.

[0047] A ring gear of the planetary gear set RS can be connected to the second transmission input shaft 26 or the first transmission input shaft 24 to provide a drive.

[0048] A planet carrier of the planet gear set RS is effectively connected to the first transmission input shaft 24.

[0049] A sun gear of the planetary gear set RS is effectively connected to the third transmission input shaft 28.

[0050] In the embodiment shown, the first transmission input shaft 24, the first countershaft 30 and the second countershaft 32 are designed as solid shafts.

[0051] The second transmission input shaft 26 and the third transmission input shaft 28 are designed as hollow shafts, wherein the third transmission input shaft 28 surrounds the first transmission input shaft 24 at least partially, and the second transmission input shaft 26 surrounds the planet gear set RS and the third transmission input shaft 28 at least partially.

[0052] The hybrid transmission has seven switching elements A to G and one combustion engine clutch K0.

[0053] The combustion engine coupling K0 is designed to detachably connect the first transmission input shaft 24 to the combustion engine 16 in a drive-effective manner.

[0054] A first switching element A is designed to switch the first spur gear pair ST1 in a drive-effective manner, i.e. to establish a drive-effective connection between the second transmission input shaft 26 and the first countershaft 30.

[0055] A second switching element B is designed to switch the second spur gear pair ST2 in a drive-effective manner, i.e. to establish a drive-effective connection between the second transmission input shaft 26 and the second countershaft 32.

[0056] A third switching element C is designed to switch the third spur gear pair ST3 in a drive-effective manner, i.e. to establish a drive-effective connection between the first transmission input shaft 24 and the first countershaft 30.

[0057] A fourth switching element D engages the fourth spur gear pair ST4, thereby establishing a drive-effective connection between the first transmission input shaft 24 and the second countershaft 32.

[0058] A fifth switching element E is designed to connect the first transmission input shaft 24 to the second countershaft 32 in a drive-effective manner.

[0059] A sixth switching element F is designed to connect the ring gear of the planetary gear set RS to the first transmission input shaft 24 in a drive-effective manner. Consequently, the sixth switching element F locks the planetary gear set by effectively connecting the planet carrier and the ring gear.

[0060] A seventh switching element G is designed to connect the second transmission input shaft 26 to a ring gear of the planetary gear set RS in a drive-effective manner.

[0061] It goes without saying that other blocking variants are also conceivable, in which two of the three planetary gear set elements of the RS planetary gear set are effectively connected to each other for drive purposes.

[0062] In the illustrated embodiment, the switching elements A to F and the combustion engine clutch K0 are designed as positive-locking switching elements, for example, claw switching elements. Furthermore, the first switching element A and the second switching element B are combined to form a double switching element with only one actuator. The third switching element C and the fourth switching element D are combined to form a double switching element. The seventh switching element G and the sixth switching element F are combined to form a double switching element. The fifth switching element E and the combustion engine clutch K0 are also combined to form a double switching element. In this embodiment, the second electric drive motor 20 can preferably be designed as a high-voltage starter-generator.

[0063] In Fig. Figure 36 shows, in the first column of a switching matrix, the combustion gear stages V1, V2, the state charging-in-neutral, the electric gear stages for the second electric drive motor 20 E2.1, E2.2, the electric gear stages for the first electric drive motor 14 E1.1, E1.2, two electrodynamic superposition states ECVT1, ECVT2, and a purely electric, electrodynamic superposition state eECVT1. Columns 2 through 9 show the switching states of the combustion engine clutch K0 and the switching elements A through G, where an "X" indicates that the respective switching element or combustion engine clutch K0 is closed, thus effectively connecting the associated transmission components. If no entry is present, it can be assumed that the corresponding switching element or combustion engine clutch K0 is open, i.e., transmitting no drive power.

[0064] The first combustion stage V1 can be set up by engaging the combustion engine clutch K0 and the third switching element C.

[0065] Engaging the combustion engine clutch K0 and the fourth switching element D sets up the second combustion stage V2.

[0066] A state of loading-in-neutral LIN can be established by engaging the combustion engine clutch K0 and the sixth switching element F.

[0067] A first electrical gear stage for the second electric drive motor 20 E2.1 can be set up by inserting the third switching element C and the sixth switching element F.

[0068] Inserting the fourth switching element D and the sixth switching element F sets up a second electrical gear stage for the second electric drive motor 20 E2.2.

[0069] The first electric drive stage for the first electric drive motor 14 E1.1 can be set up by inserting the first switching element A.

[0070] Inserting the second switching element B sets up the second electrical gear stage for the first electric drive motor 14 E1.2.

[0071] The first electrodynamic superposition state ECVT1 can be established by closing the combustion engine clutch K0, the first switching element A and the seventh switching element G.

[0072] The second electrodynamic superposition state ECVT2 can be established by closing the combustion engine clutch K0, the second switching element B and the seventh switching element G.

[0073] The purely electrical electrodynamic superposition state eECVT1 can be set up by closing the fifth switching element E and the seventh switching element G.

[0074] If only the first switching element A is closed and the first electric drive motor 14 is connected to the ring gear of the planetary gear set RS via the seventh switching element G, a so-called EDA mode is activated. This is designated ECVT1 in the switching matrix 36. In this switching state, the planetary gear set serves as a superimposed transmission. The combustion engine 16 is connected to the planet carrier of the planetary gear set RS. In this switching state, starting and driving are possible even with an empty electrical energy storage device 22.

[0075] If only the second switching element B is closed and the first electric drive motor 14 is connected to the ring gear of the planetary gear set via the seventh switching element G, a second driving range ECVT2 is engaged. This driving range is preferably intended for higher speeds.

[0076] With the combustion engine clutch K0 open, the second electric drive motor 20 can be used for purely electric operation. In this mode, the second electric drive motor 20 provides power instead of the combustion engine 16. In this purely electric electrodynamic superposition state eECVT1, it is also possible to support the purely electric switching operation for the first electric drive motor 14 from the electric gear stage E1.1 to the electric gear stage E1.2 by having the second electric drive motor 20 support the torque at the sun gear of the planetary gear set RS during the switching operation. This is known as a purely electric EDS, or electrodynamic switching operation.

[0077] For driving with the combustion engine, the combustion engine forward gear stages V1 and V2 are available. These two gear stages can be switched independently of the first electric drive motor 14.

[0078] The second electric drive motor 20 can perform, among other functions, the following: It enables the combustion engine 16 to be started from purely electric drive. It ensures an on-board power supply in the charging-in-neutral state. In particular, serial creeping and driving in both forward and reverse are possible. It can support the speed control of the combustion engine 16 during coupling and gear changes. Electrodynamic shifting is possible between the gear stages for the first electric drive motor 14 and / or the second electric drive motor 20. Specifically, the second electric drive motor 20 can be used in addition to the first electric drive motor 14 for purely electric driving, with the second electric drive motor 20 driving the first transmission input shaft 24 instead of the combustion engine 16.

[0079] In combustion engine mode, the first electric drive motor 14 can be decoupled when the combustion engine 16 is operating in one of the combustion gear stages V1 or V2. For this purpose, the first switching element A or the second switching element B is opened. This enables efficient, purely combustion engine-based driving, as no drag losses occur at the first electric drive motor 14.

[0080] It is understood that a friction clutch can also be used instead of a dog clutch K0 for the combustion engine. A particular advantage is that a friction clutch can also be opened under load, such as during emergency braking or a malfunction of the combustion engine 16. Furthermore, a friction clutch K0 for the combustion engine can also be closed under a speed differential, so that a so-called momentum start of the combustion engine 16 using the second electric drive 20 is possible. For this purpose, the sixth switching element F must be closed, whereby the combustion engine 16 is started by the second electric drive 20 using its inertial mass.

[0081] In Fig. Figure 4 shows another variant of a hybrid transmission 18 according to the invention. In contrast to the one in Fig. In the embodiment shown in Figure 2, the third spur gear pair ST3 and the fourth spur gear pair ST4 are assigned to the third transmission input shaft 28. Furthermore, the third transmission input shaft 28 does not have a connecting gear for connecting the second electric drive motor 20, since the second electric drive motor 20 is connected to the third transmission input shaft 28 by means of the fixed gear of the third spur gear pair ST3 or the fourth spur gear pair ST4. In order to enable the dual use of the third spur gear pair ST3 and the fourth spur gear pair ST4 for connecting the second electric drive motor 20, the gear ratios that can be set with these spur gear pairs are, in contrast to the one shown in Figure 2, different from those shown in Figure 2. Fig. 2 shown embodiment is bound to the sun gear of the planetary gear set RS.

[0082] Consequently, the combustion engine gear stages V1, V2 can be reached by locking the planetary gear set RS, i.e. by engaging the sixth shift element F.

[0083] These changes result in 18 volts with the hybrid transmission according to the Fig. 4 Two further electrodynamic superposition states ECVT3, ECVT4 can be set up, in which the second electric drive machine 20 can be connected to the output 34 with a longer gear ratio.

[0084] In Fig. 5 is the hybrid transmission according to the Fig. Figure 4 is shown in a simplified representation in the manner of a circuit diagram. The individual connections to the individual shafts, which can be established by the switching elements A to G and the combustion engine coupling K0, are shown in the manner of an electrical switch.

[0085] The RS planetary gear set is represented as a circle. The ring gear, the planet carrier, and the sun gear are also represented as circles with the letters "H", "P", and "S".

[0086] Furthermore, the gear ratios that can be set using additional pairs of spur gears are represented as simple quadrilaterals.

[0087] The combustion engine 16 can therefore be effectively connected to a planetary gear carrier of the planetary gear set RS by means of the combustion engine coupling K0.

[0088] The first electric drive motor 14 can be effectively connected to a ring gear of the planetary gear set RS by inserting the seventh switching element G. The planetary gear set RS can be locked in place by inserting the sixth switching element F, whereby the ring gear of the planetary gear set RS is effectively connected to the planet carrier of the planetary gear set RS.

[0089] The first electric drive machine 14 can be connected to the first intermediate shaft 30 by inserting the first switching element A and can be effectively connected to the output 34 via a first output transmission.

[0090] By inserting a second switching element B, the first electric drive motor 14 can be connected to the second countershaft 32 by means of a second transmission and further connected to the output 34 via a second output transmission.

[0091] The sun gear of the planetary gear set RS can be connected to the first countershaft 30 via a third transmission by inserting the third switching element C, i.e. by means of the third spur gear pair ST3, and further connected to the output 34 via the output transmission of the first countershaft 30.

[0092] By inserting a fourth switching element D, the sun gear of the planetary gear set RS can be connected to the second countershaft 32 via a fourth transmission, i.e. by means of the fourth spur gear pair ST4, and further via the output transmission of the second countershaft 32 to the output 34.

[0093] The second electric drive motor 20 can be effectively connected to the third transmission input shaft 28 or the sun gear of the planetary gear set RS by means of a pre-transmission, whereby by inserting the fifth switching element E a planet carrier of the planetary gear set RS can be effectively connected to the second countershaft 32 via an EDS transmission, i.e. by means of the fifth spur gear pair ST5, and further via the output transmission of the second countershaft 32 to the output 34.

[0094] In Fig. 6 are analogous to the switching matrix 36 according to the Fig. 3 in a switching matrix 38 the switching states of the hybrid transmissions according to the Fig. 4 and Fig. 5 shown.

[0095] To engage a first combustion stage V1 for the combustion engine 16, the combustion engine clutch K0, the third switching element C and the sixth switching element F must be closed.

[0096] The second combustion stage V2 can be set up by closing the combustion engine clutch K0, the fourth switching element D and the sixth switching element F.

[0097] The state of loading-in-neutral LIN can be set up by closing the combustion engine clutch K0 and the sixth switching element F.

[0098] The first electric drive stage for the second electric drive motor 20 E2.1 can be set up by closing the third switching element C.

[0099] Closing the fourth switching element D sets up a second electrical stage for the second electric drive motor 20 E2.2.

[0100] The electrical stages for the first electric drive motor 14, as well as the first electrodynamic superposition state ECVT1, the second electrodynamic superposition state ECVT2, and the purely electric electrodynamic superposition state eECVT1, switch on analogously to the one described in Fig. The circuit diagram shown in section 3 is included only for the sake of completeness.

[0101] A third electrodynamic superposition state ECVT3 can be established by engaging the combustion engine clutch K0, the third switching element C and the seventh switching element G.

[0102] Engaging the combustion engine clutch K0 and closing the fourth switching element D and the seventh switching element G establishes a fourth electrodynamic superposition state ECVT4.

[0103] In Fig. Figure 7 shows another variant of a hybrid transmission 18 according to the invention. In contrast to the one in Fig. In the embodiment shown in section 2, the hybrid transmission 18 comprises the following: Fig. 7 only four spur gear pairs ST1, ST2, ST4 and ST5, wherein a drive-effective connection between the first transmission input shaft 24 and the first countershaft 30 can be established by means of the fifth spur gear pair ST5. This drive-effective connection is established by closing the fifth switching element E. In contrast to the one in Fig. In the embodiment shown in Figure 2, the fifth spur gear pair ST5 is arranged with the fourth spur gear pair ST4 in a double gear set plane; consequently, these two spur gear pairs share a common fixed gear on the first transmission input shaft 24. It is understood that with the omission of the third spur gear pair ST3, the third switching element C is also no longer present in the hybrid transmission. However, the remaining connections are identical to those shown in Figure 2. Fig. 2 embodiment shown.

[0104] In Fig. Figure 8 shows another variant of a hybrid transmission 18 according to the invention. In contrast to the one in Fig. In the embodiment shown in Figure 7, the first spur gear pair ST1 and the second spur gear pair ST2 are no longer arranged in a double gear plane. Consequently, the second transmission input shaft 26 has two fixed gears, one of which meshes with a loose gear arranged on the first countershaft 30 and forms the first spur gear pair ST1. The other fixed gear on the second transmission input shaft 26 meshes with a loose gear arranged on the second countershaft 32 and forms the second spur gear pair ST1. The hybrid transmissions 18 according to the Fig. 7 and Fig. 8 switch on simultaneously.

[0105] In Fig. 9 are the hybrid transmissions according to the Fig. 7 and Fig. 8 schematically simplified analogous to Fig. 5 shown.

[0106] The combustion engine 16 can be effectively connected to a planetary gear carrier of the planetary gear set RS by engaging the combustion engine coupling K0.

[0107] A ring gear of the planetary gear set RS can be effectively connected to the first electric drive shaft 14 by inserting the seventh switching element G.

[0108] Inserting the sixth switching element F locks the planetary gear set RS by effectively connecting the ring gear to the planetary gear carrier.

[0109] The sun gear of the planetary gear set RS is effectively connected to the second electric drive motor 20.

[0110] The first countershaft 30 is connected to the output 34 via a first output reduction and can be effectively connected to the first electric drive motor 14 via a first reduction by inserting the first switching element A and to the planet carrier of the planet gear set RS via the EDS reduction by inserting a fifth switching element E.

[0111] The second countershaft 32 is connected to the output 34 via a second output ratio and can be connected to the first electric drive motor 14 via the second ratio by inserting a second switching element B and to the planet carrier of the planet gear set RS via the fourth ratio by inserting a fourth switching element D.

[0112] The first, second, and fourth gear ratios are each provided by the first, second, and fourth spur gear pairs ST1, ST2, and ST4, respectively. Fig. 10 are in a switching matrix 40 analogous to the switching matrices 38 and 36 of the Fig. 3 and Fig. 6 the switching states of the hybrid transmissions according to the Fig. 7, Fig. 8 and Fig. 9 shown.

[0113] The first electric drive stage for the second electric drive motor 20 E2.1 can be set up by inserting the fifth switching element E and the sixth switching element F.

[0114] Inserting the fourth switching element D and the sixth switching element F sets up a second electrical gear stage for the second electric drive motor 20 E2.2.

[0115] The remaining switching states switch analogously to the one in Fig. The switching matrix 36 shown in the 3 are included only for the sake of completeness.

[0116] In Fig. Figure 11 shows another variant of a hybrid transmission 18 according to the invention. In contrast to the one in Fig. In the embodiment shown in section 8, the hybrid transmission 18 comprises the following: Fig.11 a single countershaft 30. Consequently, the spur gear pairs ST1, ST2, ST4, and ST5 are arranged between the first two transmission input shafts 24, 26 and the countershaft 30. This embodiment can be particularly advantageous for reasons of installation space. Reducing the number of countershafts to a single countershaft 30 has no effect on functionality. In this embodiment, the double shift elements are located on the same axis, so that, unlike the embodiments shown previously, a distributed shift fork for the shift elements is no longer required. Not shown, but conceivable, is also an axis-parallel connection of the first electric drive motor 14, which in this variant can create additional installation space flexibility.

[0117] 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 examples and not as limiting. The invention is not limited to the disclosed embodiments. Other embodiments or variations will become apparent to a person skilled in the art when using the present invention and upon a detailed analysis of the drawings, the disclosure, and the subsequent claims.

[0118] In the claims, the words "comprise" and "with" do not preclude the presence of further elements or steps. The undefined article "a" or "an" does not preclude the presence of multiple elements. A single element or unit can perform the functions of several of the units mentioned in the claims. The mere mention of some measures in several different dependent claims is not to be understood as precluding the advantageous use of a combination of these measures. For example, a method for operating a motor vehicle powertrain 12 can be implemented in the form of a computer program executed on a control unit for the motor vehicle powertrain 12. A computer program can be stored / distributed on a non-volatile data carrier, such as an optical storage medium or 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 punctuation in the patent claims is not to be understood as limiting. REFERENCE MARK LIST: 10 motor vehicle 12 Automotive Powertrain 14 first electric drive motor 16 Internal combustion engine 18 hybrid transmissions 20 second electric drive motor 22 Energy storage 24 first gearbox input shaft 26 second gearbox input shaft 28 third gearbox input shaft 30 first countershaft 32 second countershaft 34 Drive 36 switching matrix 38 switching matrix 40 switching matrix AG Switching Elements K0 combustion engine clutch RS planetary gear set ST1-ST5 spur gear pairs

Claims

[1] 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 (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 third transmission input shaft (28) for connecting the hybrid transmission (18) with a second electric drive motor (20) of the motor vehicle (10); a planetary gear set (RS) which is connected to the first transmission input shaft (24) and the third transmission input shaft (28) and can be connected to the second transmission input shaft (26); a first intermediate shaft (30) which is effectively connected to an output (34) of the hybrid transmission (18); spur gear pairs (ST1, ST2, ST3, ST4, ST5) arranged in several gear set levels to form gear stages; and several gearshift devices with switching elements (A, B, C, D, E, F, G) for engaging the gear stages; wherein at least one purely electric electrodynamic superposition state (eECVT1) for purely electric starting and / or for purely electric load switching can be set up by means of the planetary gear set (RS); and wherein the first transmission input shaft (24), the second transmission input shaft (26) and the third transmission input shaft (28) are arranged coaxially to each other; the first transmission input shaft (24) is designed as a solid shaft; the second transmission input shaft (26) and the third transmission input shaft (28) are designed as hollow shafts; the third transmission input shaft (28) surrounds the first transmission input shaft (24) at least partially; and / or the second transmission input shaft (26) surrounds the third transmission input shaft (28) at least partially. [2] Hybrid transmission (18) according to claim 1, wherein the third transmission input shaft (28) is designed without shift elements. [3] Hybrid transmission (18) according to one of the preceding claims, wherein the hybrid transmission (18) comprises a second intermediate shaft (32) which is effectively connected to the output (34) of the hybrid transmission (18). [4] Hybrid transmission (18) according to one of the preceding claims, wherein the first transmission input shaft (24), the second transmission input shaft (26) and / or the third transmission input shaft (28) has a double gear plane. [5] Hybrid transmission (18) according to one of the preceding claims, wherein the hybrid transmission (18) comprises exactly four or exactly five gear-forming spur gear pairs (ST1, ST2, ST3, ST4, ST5) and a planetary gear set (RS) for forming the gear stages. [6] Hybrid transmission (18) according to one of the preceding claims, wherein the first transmission input shaft (24) comprises an internal combustion engine coupling (K0) for releasably connecting the first transmission input shaft (24) to the internal combustion engine (16) in a drive-effective manner. [7] Hybrid transmission (18) according to one of the preceding claims, wherein the first transmission input shaft (24) is effectively connected to a planet carrier of the planet gear set (RS); the second transmission input shaft (26) is effectively connected to a ring gear of the planet gear set (RS); and / or the third transmission input shaft (28) is effectively connected to a sun gear of the planet gear set (RS). [8] Hybrid transmission (18) according to one of the preceding claims, wherein a first switching element (A) is configured to connect the second transmission input shaft (26) to the countershaft (30, 32) by means of a first spur gear pair (ST1) in a drive-effective manner; a second switching element (B) is designed to connect the second transmission input shaft (26) to the countershaft (30, 32) by means of a second spur gear pair (ST2) in a drive-effective manner; preferably a third switching element (C) is designed to connect the first transmission input shaft (24) or the third transmission input shaft (28) to the countershaft (30, 32) by means of a third spur gear pair (ST3) in a drive-effective manner; a fourth switching element (D) is designed to connect the first transmission input shaft (24) or the third transmission input shaft (28) to the countershaft (30, 32) by means of a fourth spur gear pair (ST4) in a drive-effective manner; and / or a fifth switching element (E) is configured to connect the first transmission input shaft (24) to the countershaft (30, 32) by means of the third spur gear pair (ST3) or a fifth spur gear pair (ST5) in a drive-effective manner; a sixth switching element (F) is configured to lock the planetary gear set (RS); and / or a seventh switching element (G) is designed to connect the first transmission input shaft (24) to the second transmission input shaft (26) in a drive-effective manner. [9] Hybrid transmission (18) according to one of the preceding claims, wherein the switching elements (A, B, C, D, E) are designed as positive-locking switching elements (A, B, C, D, E); and / or at least two of the switching elements (A, B, C, D, E), preferably all switching elements (A, B, C, D, E), are designed as double switching elements and can be actuated by a double-acting actuator. [10] Motor vehicle powertrain (12) for a motor vehicle (10), comprising: a hybrid transmission (18) according to one of the preceding claims; an internal combustion engine (16) which is connectable to the first transmission input shaft (24); a first electric drive motor (14) which is effectively connected to the second transmission input shaft (26) for driving purposes; and a second electric drive motor (20) which is effectively connected to the third transmission input shaft (28). [11] Motor vehicle powertrain (12) according to claim 10, wherein the second electric drive motor (20) is designed as a high-voltage starter-generator and is preferably arranged parallel to the axis of the third transmission input shaft (28). [12] Motor vehicle powertrain (12) according to claim 10 or 11, wherein the first electric drive machine (14) is designed as a coaxial machine; and the planetary gear set (RS) and / or a double switching element comprising two switching elements of the switching elements (A, B, C, D, E, F, G) for engaging the gear stages is arranged at least sectionally axially and / or radially within the first electric drive machine (14). [13] Method for operating a motor vehicle powertrain (12) according to any one of claims 10 to 12. [14] Motor vehicle (10) comprising a motor vehicle powertrain (12) according to any one of claims 10 to 12; and an energy storage device (22) for storing energy to supply the first electric drive motor (14) and / or the second electric drive motor (20).

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