Transmission for a vehicle's drivetrain

Abstract

Transmission (1) for a drive train of a vehicle (100), comprising • a first transmission input shaft (W1) arranged on a first axis of rotation (A1) for connecting an internal combustion engine (VM), • a second transmission input shaft (W2) arranged on a second axis of rotation (A2) for connecting a first electric machine (EM1), • a countershaft (W3) arranged on a third axis of rotation (A3) with a first gear (31), a second gear (32) and a third gear (33), wherein the first gear (31) on the third axis of rotation (A3) is in mesh with a first gear (11) on the first axis of rotation (A1) and forms a first spur gear stage (ST1), wherein the second gear (32) on the third axis of rotation (A3) is in mesh with a second gear (12) on the first axis of rotation (A1) and forms a second spur gear stage (ST2), wherein the third gear (33) on the third axis of rotation (A3) is in mesh with a third gear (13) on the first axis of rotation (A1) and forms a third spur gear stage (ST3), • at least one first planetary gear set (P1) arranged on the first axis of rotation (A1) and designed as a superimposed gear set with a first element (P11), a second element (P12) and a third element (P13), • a main output shaft (W4) which is arranged on the first axis of rotation (A1) and is non-rotatably connected to the third element (P13) of the first planetary gear set (P1), • a first switching element (A), a second switching element (B), a third switching element (C), a fourth switching element (D) and a fifth switching element (E), wherein the first switching element (A) in the closed state connects two of the three elements (P11, P12, P13) of the first planetary gear set (P1) in a rotationally fixed manner, wherein the second switching element (B) in the closed state connects the first and second gear (31, 32) on the third axis of rotation (A3) in a rotationally fixed manner, wherein the third switching element (C) in the closed state connects the first or third gear (31, 33) on the third axis of rotation (A3) to the countershaft (W3) in a rotationally fixed manner, wherein the fourth switching element (D) in the closed state effectively connects the second element (P12) of the first planetary gear set (P1), the second transmission input shaft (W2) and the countershaft (W3) to each other, wherein the fifth switching element (E) in the closed state connects the second gear (32) on the third axis of rotation (A3) to the countershaft (W3) in a rotationally fixed manner, wherein the first, second and third axes of rotation (A1, A2, A3) are arranged parallel to each other.

Description

[0001] The invention relates to a transmission for a vehicle drivetrain and a drivetrain comprising an internal combustion engine, at least one electric machine, and such a transmission. The transmission is thus designed as a hybrid transmission.

[0002] For example, German patent DE 10 2011 005 562 A1 discloses a transmission for a hybrid drive in a motor vehicle, comprising 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 disconnect clutch and to the output shaft via a first group of selectively switchable gear sets. The second input shaft can be connected to the rotor of an electric motor and to the first input shaft via a planetary gear set, and to the output shaft via a second group of selectively switchable gear sets. Both input shafts can be connected to each other via a switchable coupling device.The transmission is derived from a dual-clutch transmission with two coaxial input shafts, the first input shaft of which is centrally arranged, 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 in place of the gear set and its associated gear clutch that 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.

[0003] Furthermore, DE 10 2021 203 726 A1 discloses a hybrid transmission arrangement for a motor vehicle, comprising a first shaft for supplying internal combustion engine drive power, a second shaft connected to a first electric motor, a third shaft for outputting power, a fourth shaft offset axially from the third shaft, a fifth shaft connectable to the first shaft via a first coupling, and a first planetary gear set. The first planetary gear set has a first element, a second element, and a third element. The second shaft is connectable to the first shaft via a second coupling. The second shaft is connected to the first element. The fifth shaft is connected to the second element. The third shaft is connected to the third element.

[0004] Similarly, US 2017 / 0 282 700 A1, DE 10 2020 216 298 A1 and DE 10 2008 031 456 A1 reveal different transmissions for hybrid powertrains.

[0005] The object of the present invention is to provide an alternative transmission for a vehicle. In particular, the transmission should be compact and efficient, and should have multiple driving modes. This object is achieved by a transmission with the features of claim 1. Advantageous embodiments are the subject of the dependent claims, the following description, and the figures.

[0006] A transmission according to the invention for a drive train of a vehicle comprises • a first transmission input shaft arranged on a first axis of rotation for connecting an internal combustion engine, • a second gearbox input shaft arranged on a second axis of rotation for connecting a first electric machine, • a countershaft arranged on a third axis of rotation with a first gear, a second gear and a third gear, wherein the first gear on the third axis of rotation is in mesh with a first gear on the first axis of rotation and forms a first spur gear stage, wherein the second gear on the third axis of rotation is in mesh with a second gear on the first axis of rotation and forms a second spur gear stage, wherein the third gear on the third axis of rotation is in mesh with a third gear on the first axis of rotation and forms a third spur gear stage, • at least one first planetary gear set arranged on the first axis of rotation and designed as a superimposed gear set with a first element, a second element and a third element, • a main output shaft arranged on the first axis of rotation and non-rotatably connected to the third element of the first planetary gear set, • a first switching element, a second switching element, a third switching element, a fourth switching element and a fifth switching element, wherein the first switching element, in the closed state, connects two of the three elements of the first planetary gear set in a rotationally fixed manner to lock the planetary gear set, wherein the second switching element, in the closed state, connects the first and second gear on the third axis of rotation in a rotationally fixed manner to effectively connect the first and third spur gear stages to each other, wherein the third switching element, in the closed state, connects the first or third gear on the third axis of rotation to the countershaft in a rotationally fixed manner to effectively connect the first spur gear stage and the countershaft or the third spur gear stage and the countershaft to each other, wherein the fourth switching element, in the closed state, connects the second element of the first planetary gear set,the second transmission input shaft and the countershaft effectively connect to each other for driving purposes, wherein the fifth switching element, in the closed state, connects the second gear on the third axis of rotation to the countershaft in a rotationally fixed manner in order to effectively connect the second spur gear stage and the countershaft to each other for driving purposes, wherein the first, second and third axes of rotation are arranged parallel to each other.

[0007] A "drive-effective connection" or a "connection" of a shaft or device to another shaft or device means that these shafts or devices are either directly connected to each other or can be indirectly connected to each other via at least one further component, in particular via further shafts and gears.

[0008] For example, the crankshaft of the internal combustion engine is directly or via at least one other shaft effectively connected to the first transmission input shaft. For example, the crankshaft of the internal combustion engine is effectively connected to the first transmission input shaft via at least one other shaft, gears, and / or a traction element. For example, the rotor shaft of the first electric machine is directly or via at least one other shaft effectively connected to the second transmission input shaft. For example, the rotor shaft of the first electric machine is effectively connected to the second transmission input shaft via at least one other shaft, gears, and / or a traction element. The two transmission input shafts are axially parallel to each other. A transmission input shaft is understood to be a transmission element designed for connection to a respective drive machine.

[0009] The term "shaft" does not refer exclusively to, for example, a cylindrical, rotatably mounted gear element for transmitting torque, but rather also encompasses general connecting elements that join individual components or elements together, in particular connecting elements that non-rotatably join several elements. Two non-rotatably joined shafts can be formed in one piece.

[0010] The drive power generated by the internal combustion engine and the first electric machine is combined or superimposed in the superimposed transmission and transmitted, at least indirectly, to the wheels of a drive axle via the main output shaft. Preferably, the first element of the first planetary gear set is designed as a sun gear, the second element as a ring gear, and the third element as a planet carrier. The first planetary gear set comprises several planet gears rotatably mounted on the planet carrier and meshing with the sun gear and the ring gear. The superimposed transmission serves in particular as a summing transmission.

[0011] The first switching element, in its closed state, locks the first planetary gear set by connecting two of its three elements. When two shafts of the first planetary gear set are rotationally fixed together, the first planetary gear set is locked and thus in a closed loop. By locking the first planetary gear set, the gear ratio is independent of the number of teeth of the meshing elements i=1. Preferably, the sun gear and the ring gear are rotationally fixed together. Alternatively, the first switching element is used to rotationally fix the planet carrier and the sun gear, or the planet carrier and the ring gear.

[0012] A "switching element" is understood to be a switchable device that, in a closed state, connects two shafts in a rotationally fixed manner and, in an open state, decouples the two shafts from each other, allowing them to rotate relative to each other.

[0013] When the drive power from the combustion engine and the first electric motor is combined, the vehicle operates in hybrid mode, with two of the five shift elements closed. The transmission allows for several hybrid driving modes, specifically four gears. Furthermore, the electric motor can provide traction assistance during gear changes in hybrid mode. These gear changes can be output-assisted or electrodynamic. Starting can also be electrodynamic. Two electrodynamic driving modes are implemented via the first planetary gear set, requiring either the fourth or fifth shift element to be closed. Additionally, the first electric motor can be connected to the combustion engine independently of the output, provided only the third shift element is closed.The first electric machine and the combustion engine then rotate at a fixed ratio to each other. This allows the combustion engine to be started using the first electric machine, and also enables the first electric machine to operate as a generator, thus realizing the "Charge in Neutral" driving mode. During "Charge in Neutral" mode, the first electric machine can charge an electrical energy storage device or power the vehicle's electrical consumers. A consumer can also be another electric machine, for example, located on another vehicle axle, particularly as part of an electric rear axle.

[0014] Preferably, the transmission has exactly five positive-locking switching elements. A "positive-locking switching element" is defined as a switching element that has teeth and / or jaws for connecting two shafts, which interlock to create a rotationally fixed connection. The transmission of power from one coupling part of the switching element to the other coupling part of the switching element in a fully closed state occurs primarily through this positive locking. For example, all five switching elements are designed as jaw couplings. Positive-locking switching elements increase the compactness and efficiency of the transmission.

[0015] According to a preferred embodiment, the first gear is non-rotatably connected to the first element of the first planetary gear set on the first axis of rotation. According to a preferred embodiment, the second gear is non-rotatably connected to the second element of the first planetary gear set on the first axis of rotation. For example, the first gear is non-rotatably connected to the sun gear of the first planetary gear set on the first axis of rotation, and the second gear is non-rotatably connected to the ring gear of the first planetary gear set on the first axis of rotation.

[0016] According to a preferred embodiment, the third gear on the first axis of rotation is designed as a loose gear and can be non-rotatably connected to the second element of the first planetary gear set by means of the fourth switching element. Thus, the fourth switching element is then located on the first axis of rotation. Alternatively, the third gear on the first axis of rotation is non-rotatably connected to the second element of the first planetary gear set, wherein the third gear on the third axis of rotation is designed as a loose gear and is non-rotatably connected to the countershaft when the fourth switching element is closed. Thus, the fourth switching element is then located on the third axis of rotation.

[0017] Preferably, the first and fourth switching elements are arranged on the first axis of rotation, with the second, third, and fifth switching elements being arranged on the third axis of rotation. Alternatively, the first switching element is arranged on the first axis of rotation, with the second, third, fourth, and fifth switching elements being arranged on the third axis of rotation.

[0018] According to a preferred embodiment, the transmission has a differential arranged on the first axis of rotation, comprising a differential input shaft and two differential output shafts, wherein the differential input shaft is at least indirectly connected to the main output shaft. Drive power is transmitted to the differential via the main output shaft, with the drive power being distributed within the differential to the two side shafts and transmitted to a drive wheel of the vehicle operatively connected to the respective side shaft. Preferably, the first transmission input shaft and the main output shaft are designed as hollow shafts, with the second differential output shaft extending axially through the transmission, in particular through the first transmission input shaft and the main output shaft. This allows the transmission to be designed more compactly in the radial direction.The differential can be designed, for example, as a ball differential, bevel gear differential, spur gear differential, or planetary gear differential. The differential's side shafts are arranged together on a single output shaft of the vehicle. Preferably, this output shaft is the front-wheel drive axle of a passenger car. Therefore, the transmission is preferably installed in the vehicle in a front-transverse configuration.

[0019] According to a preferred embodiment, the transmission has a second planetary gear set arranged on the first axis of rotation, positioned in the power flow between the first planetary gear set and the differential. The second planetary gear set comprises a first element that is rotationally fixed to the main output shaft, a second element that is stationary on a rotationally fixed component, and a third element that is rotationally fixed to the differential input shaft. Preferably, the first element of the second planetary gear set is configured as a sun gear, the second element is configured as a ring gear, and the third element is configured as a planet carrier. The second planetary gear set is configured as a fixed transmission stage. The rotationally fixed component can be a housing, a part of a housing, or a component rotationally fixed to it.

[0020] According to a preferred embodiment, the second transmission input shaft has a fixed gear that meshes with an intermediate gear, the intermediate gear further meshing with one of the two gears that form the third spur gear stage. In other words, the intermediate gear meshes either with the fixed gear on the second axis of rotation and the third gear on the first axis of rotation, or with the fixed gear on the second axis of rotation and the third gear on the third axis of rotation, thereby directly connecting the first electric motor to the third spur gear stage. This allows at least one gear to be omitted. Reference is made to the first and second embodiments according to Fig. 2 and Fig. 4 referred.

[0021] Alternatively, the second transmission input shaft has a fixed gear that meshes with an intermediate gear, the intermediate gear further meshing with a fourth gear on the first axis of rotation, which is rotationally fixed to the third gear on the first axis of rotation. For this purpose, reference is made to the third embodiment according to Fig. 5 referred.

[0022] Alternatively, the second transmission input shaft has a fixed gear that meshes with an intermediate gear, the intermediate gear further meshing with a fourth gear on the third axis of rotation, which is non-rotatably connected to the countershaft. For this purpose, reference is made to the fourth embodiment according to Fig. 6 referred.

[0023] According to a preferred embodiment, the second and third switching elements are combined to form a double switching element. According to a preferred embodiment, the fourth and fifth switching elements are combined to form another double switching element. Alternatively, the third and fifth switching elements are combined to form a double switching element. Each double switching element can be switched by means of a single actuator.

[0024] According to a preferred embodiment, a damping device is arranged in the power flow upstream of the first transmission input shaft. For example, the damping device is arranged axially parallel to the first transmission input shaft. Alternatively, the damping device is arranged coaxially to the first transmission input shaft. The damping device is configured to connect the crankshaft of the internal combustion engine to the transmission, in particular to the first transmission input shaft. The damping device can comprise a torsional damper and / or a vibration damper and / or a slip clutch. The torsional damper can be designed as a dual-mass flywheel. The vibration damper can be designed as a speed-adaptive vibration damper.

[0025] According to a preferred embodiment, the transmission has a switching element designed as a disconnect clutch, which is configured to decouple the first transmission input shaft from the internal combustion engine. Two electric drive modes are implemented by means of the disconnect clutch, allowing the internal combustion engine to be decoupled for purely electric driving using the first electric motor. In particular, the disconnect clutch is arranged coaxially to the internal combustion engine. For example, the disconnect clutch is arranged parallel to the axis of the first transmission input shaft. Alternatively, the disconnect clutch is arranged coaxially to the first transmission input shaft. The disconnect clutch is located in the drivetrain between the internal combustion engine and the first transmission input shaft. Furthermore, the disconnect clutch can be arranged in the power flow from the internal combustion engine downstream of the damping device.The disconnect clutch can be designed as either a positive-locking or a friction-locking switching element. A positive-locking disconnect clutch is more compact and exhibits lower energy losses than a friction-locking one. An advantage of a friction-locking disconnect clutch is its ability to open even under load, for example, during emergency braking or in the event of an internal combustion engine malfunction. In particular, a friction-locking disconnect clutch can also close even when the two clutch components are rotating at different speeds, enabling, for example, a so-called "momentum start" of the internal combustion engine using the first electric motor. This process utilizes the inertial mass of the electric motor to start the internal combustion engine.

[0026] A drive train according to the invention comprises an internal combustion engine, a first electric machine, and a transmission according to the invention, wherein the internal combustion engine and the first electric machine are arranged parallel to each other. Preferably, the drive train includes a second electric machine for driving a further drive axle of the vehicle. The above definitions and descriptions of the technical effects, advantages, and advantageous embodiments of the transmission according to the invention also apply mutatis mutandis to the drive train according to the invention.

[0027] Advantageous embodiments of the invention, which are explained below, are illustrated in the drawings, where identical elements are designated with the same reference numeral. They show: Fig. 1 a highly abstracted schematic view of a vehicle with a drive train comprising a transmission according to the invention; Fig. 2 a highly abstracted schematic view of a drive train with a transmission according to a first embodiment according to the invention; Fig. 3 a switching matrix for the powertrain according to Fig. 2 Fig. 4 a highly abstracted schematic view of a transmission according to the invention in a second embodiment; Fig. 5 a highly abstracted schematic view of a transmission according to the invention in a third embodiment; Fig. 6 a highly abstracted schematic view of a transmission according to the invention in a fourth embodiment; Fig. 7 a highly abstracted schematic view of a transmission according to the invention in a fifth embodiment; Fig. 8 a highly abstracted schematic view of a transmission according to the invention in a sixth embodiment; and Fig. 9 a highly abstracted schematic view of a drive train with a transmission according to a seventh embodiment.

[0028] Fig. Figure 1 shows the vehicle 100 with a first drive axle 101 with two wheels R1, R2 and a second drive axle 102 with two wheels R3, R4. In this case, the first drive axle 101 is designed as the front axle of the vehicle 100 and is equipped with a transmission 1 designed as a hybrid transmission, which effectively connects an internal combustion engine VM and a first electric machine EM1 to the wheels R1, R2 of the first drive axle 101. A differential 2 is integrated into the transmission 1 for this purpose. The transmission 1 is arranged transversely to the longitudinal direction of the vehicle. The internal combustion engine VM and the first electric machine EM2 are arranged parallel to each other and to the transmission 1, in particular to the differential 2. A second electric machine EM2 is arranged on the second drive axle 102, i.e., the rear axle of the vehicle 100, for the electric drive of the rear axle.The second electric motor EM2 on the second drive axle 102 enables an all-wheel drive system. Specifically, the second electric motor EM2 is connected to the wheels R3 and R4 of the second drive axle 102 via a differential (not shown) on the second drive axle 102, thus providing effective drive. Alternatively, the drive on the second drive axle 102 of the vehicle 100 can be omitted, thereby saving costs, weight, and installation space.

[0029] Fig. Figure 2 schematically shows a transmission 1 according to a first embodiment of the invention. The transmission 1 comprises a first transmission input shaft W1 for connecting an internal combustion engine VM, wherein the first transmission input shaft W1 and the internal combustion engine VM are arranged on a first axis of rotation A1. Furthermore, a first switching element A, a fourth switching element D, and a switching element designed as a disconnect clutch K0 are arranged on the first axis of rotation A1, the disconnect clutch K0 being optional and thus omitted. The disconnect clutch K0 is configured to decouple the first transmission input shaft W1 from a crankshaft of the internal combustion engine VM in an open state and to connect the first transmission input shaft W1 to the crankshaft of the internal combustion engine VM in a drive-effective manner, in particular via a damping device not shown in detail, in a closed state.In this case, the disconnect coupling K0 is designed as a positive-locking switching element, but can alternatively be designed as a friction-locking switching element.

[0030] Furthermore, a first planetary gear set P1, designed as a superimposed gear set, is arranged on the first axis of rotation A1. This set comprises a first element P11, a second element P12, and a third element P13. The first element P11 of the first planetary gear set P1 is configured as a sun gear, the second element P12 is configured as a ring gear, and the third element P13 is configured as a planet carrier with multiple planet gears. The first input shaft W1 is non-rotatably connected to the first element P11 of the first planetary gear set P1. A main output shaft W4 is arranged on the first axis of rotation A1 and non-rotatably connected to the third element P13 of the first planetary gear set P1.

[0031] The gearbox 1 further comprises a second gearbox input shaft W2 for connecting a first electric machine EM1, wherein the second gearbox input shaft W2 and the first electric machine EM1 are arranged on a second axis of rotation A2. The second gearbox input shaft W2 is non-rotatably connected to a rotor shaft of the first electric machine EM1 and has a fixed gear F.

[0032] The transmission 1 further comprises a second, third, and fifth switching element B, C, E, and a countershaft W3, which are arranged on a third axis of rotation A3. In this case, all switching elements A, B, C, D, E are designed as positive-locking switching elements, but can alternatively be designed as friction-locking switching elements. The first, second, and third axes of rotation A1, A2, A3 are arranged parallel to each other.

[0033] Furthermore, a first gear 31, a second gear 32, and a third gear 33 are arranged on the third axis of rotation A3. The first gear 31 on the third axis of rotation A3 is designed as a loose gear on the countershaft W3 and meshes with a first gear 11 on the first axis of rotation A1, thereby forming a first spur gear stage ST1. The first gear 11 on the first axis of rotation A1 is rotationally fixed to the first transmission input shaft W1 and the first element E11 of the first planetary gear set P1.

[0034] The second gear 32 on the third axis of rotation A3 is designed as a loose gear on the countershaft W3 and meshes with a second gear 12 on the first axis of rotation A1, thus forming a second spur gear stage ST2. The second gear 12 on the first axis of rotation A1 is rotationally fixed to the second element E12 of the first planetary gear set P1.

[0035] The third gear 33 on the third axis of rotation A3 is designed as a fixed gear on the countershaft W3, thus rotationally fixed to the countershaft W3, and meshes with a third gear 13 on the first axis of rotation A1, thereby forming a third spur gear stage ST3. The third gear 13 on the first axis of rotation A1 is designed as a loose gear and meshes with an intermediate gear Z. Furthermore, the intermediate gear Z meshes with the fixed gear F on the second transmission input shaft W2. In other words, the first electric machine EM1 is connected to the third spur gear stage ST3 via the intermediate gear Z.

[0036] The first switching element A, when closed, connects two of the three elements P11, P12, P13 of the first planetary gear set P1 in a rotationally fixed manner, thus locking the planetary gear set P1 together. Specifically, when closed, the first switching element A connects the ring gear of the first planetary gear set P1 to the sun gear of the first planetary gear set P1, causing the first planetary gear set P1 to rotate as a unit and exhibiting a gear ratio of i=1. The second switching element B, when closed, connects the first and second gears 31, 32 on the third axis of rotation A3 in a rotationally fixed manner, so that the first and third spur gear stages ST1, ST2 are effectively connected to each other for drive purposes. The third switching element C, when closed, connects the first gear 31 on the third axis of rotation A3 in a rotationally fixed manner to the countershaft W3, so that the first spur gear stage ST1 and the countershaft W3 are effectively connected to each other for drive purposes.The fourth switching element D, when closed, connects the third gear 13 on the first axis of rotation A1 in a rotationally fixed manner to the second element P12 of the first planetary gear set P1 and the second gear 12 on the first axis of rotation A1. The fifth switching element E, when closed, connects the second gear 32 on the third axis of rotation A3 in a rotationally fixed manner to the countershaft W3, in order to transmit drive power via the second spur gear stage ST2 and the countershaft W3.

[0037] The second and third switching elements B and C are combined to form a double switching element DS and can be switched by means of a first common actuator (not shown in detail). The fourth and fifth switching elements D and E can be switched by means of a second common actuator (not shown in detail). Furthermore, the first switching element A and the disconnect coupling K0 can each be switched by means of an actuator (not shown in detail).

[0038] The advantages of the present transmission 1 are, in particular, its simple and compact design, which not only results in low component loads and low transmission losses due to the positive-locking switching elements A, B, C, D, E, K0, but also a good gear efficiency in the combustion engine and electric operation of the vehicle.

[0039] A powertrain according to Fig. 2 features several driving modes, which are selected in the shift matrix according to Fig. Figure 3 shows the switching matrix, with the columns listing the respective switching elements A, B, C, D, E, K0, and the rows listing the respective driving modes H1.1, H1.2, H1.3, H1.4, H2, H3.1, H3.2, H3.3, ZH, EDA1, EDA2, LiN, E1, E2 of the vehicle. A cross in a box of the switching matrix indicates a closed state for the respective switching element A, B, C, D, E, K0, while no entry indicates an open state for the respective switching element A, B, C, D, E, K0. The six switching elements A, B, C, D, E, K0 provide nine combustion engine gears or hybrid driving modes H1.1, H1.2, H1.3, H1.4, H2, H3.1, H3.2, H3.3, ZH, two purely electric motor gears or electric motor driving modes E1, E2, two electrodynamic starting modes EDA1, EDA2 and one driving mode charging in neutral LiN.

[0040] In a first hybrid driving mode H1.1, the disconnect clutch K0 and the second and fourth switching elements B and D are closed, while the first, third, and fifth switching elements A, C, and E are open. In another first hybrid driving mode H1.2, the disconnect clutch K0 and the second and fifth switching elements B and E are closed, while the first, third, and fourth switching elements A, C, and D are open. In another first hybrid driving mode H1.3, the disconnect clutch K0 and the second and third switching elements B and C are closed, while the first, fourth, and fifth switching elements A, D, and E are open. In yet another first hybrid driving mode H1.4, the disconnect clutch K0 and the third and fifth switching elements C and E are closed, while the first, second, and fourth switching elements A, B, and D are open.In a second hybrid driving mode H2, the disconnect clutch K0 and the third and fourth switching elements C and D are closed, while the first, second, and fifth switching elements A, B, and E are open. In a third hybrid driving mode H3.1, the disconnect clutch K0 and the first and fourth switching elements A and D are closed, while the second, third, and fifth switching elements B, C, and E are open. In a further third hybrid driving mode H3.2, the disconnect clutch K0 and the first and fifth switching elements A and E are closed, while the second, third, and fourth switching elements B, C, and D are open. In a further third hybrid driving mode H3.3, the disconnect clutch K0 and the first and third switching elements A and C are closed, while the second, fourth, and fifth switching elements B, D, and E are open.In a hybrid auxiliary driving mode ZH, the disconnect clutch K0 and the fourth and fifth switching elements D and E are closed, while the first, second, and third switching elements A, B, and C are open. In these nine hybrid driving modes H1.1, H1.2, H1.3, H1.4, H2, H3.1, H3.2, H3.3, and ZH, the combustion engine VM is always involved in propelling the vehicle, with the first electric machine EM1 able to provide additional support. In all nine hybrid driving modes H1.1, H1.2, H1.3, H1.4, H2, H3.1, H3.2, H3.3, and ZH, the disconnect clutch K0 is closed. The hybrid driving modes H1.1, H1.2, H1.3, H1.4, H2, H3.1, H3.2, H3.3, ZH form three main mechanical driving gears and the additional gear, driving mode ZH, which is designed to be shorter than the first gear, for the internal combustion engine VM.

[0041] The vehicle starts moving using the first electrodynamic driving mode EDA1. In this mode, the disconnect clutch K0 and the fourth switching element D are closed, while the first, second, third, and fifth switching elements A, B, C, and E are open. The internal combustion engine VM is then connected to the sun gear of the first planetary gear set P1, with the first electric machine EM1 supporting the torque of the internal combustion engine VM at the ring gear of the first planetary gear set P1. The planet carrier of the first planetary gear set P1 drives the main output shaft W4. From this electrodynamic driving mode EDA1, the internal combustion engine VM can enter the hybrid driving modes H1.1, H2, and H3.1 because the fourth switching element D is closed in these modes.In the second electrodynamic driving mode EDA2, the disconnect clutch K0 and the fifth shift element E are closed, while the first, second, third, and fourth shift elements A, B, C, and D are open. From this electrodynamic driving mode EDA2, the combustion engine VM can enter the hybrid driving modes H1.2, H1.4, and H3.2 because the fifth shift element E is closed in these driving modes. The electrodynamic driving modes EDA1 and EDA2 are used for both electrodynamic starting and load shifting. Load shifting is output-assisted by the first electric machine EM1. For example, a shift from first gear, particularly from driving mode H1.1, to second gear, particularly into driving mode H2, is electrodynamically assisted by the first electric machine EM1, with the fourth shift element D remaining closed.For example, a shift from second gear, in particular from driving mode H2, to third gear, in particular to driving mode H3.1, is electrodynamically assisted by the first electric machine EM1, while the fourth shift element D remains closed. The first electrodynamic driving mode EDA1 is thus used for starting and for load shifting from driving mode H1.1 to driving mode H2 and from driving mode H2 to driving mode H3.1.

[0042] The principle of load switching is illustrated by the example of switching from driving mode H1.1 to driving mode H2. In the initial state of driving mode H1.1, the disconnect clutch K0 and the second and fourth switching elements B and D are closed. The torques from the internal combustion engine VM and the first electric machine EM1 are adjusted such that, on the one hand, the desired output torque is provided, and on the other hand, the positive-locking second switching element B is de-loaded. As soon as the second switching element B is de-loaded, it is opened. Subsequently, the torques from the internal combustion engine VM and the first electric machine EM1 are adjusted such that, on the one hand, the desired output torque is provided, and on the other hand, the speed of the internal combustion engine VM decreases in order to synchronize the positive-locking third switching element C.As soon as the third switching element C is synchronized, it closes, at which point the hybrid driving mode H2 is activated. Downshifts occur analogously to upshifts, only in reverse sequence. Furthermore, overrun shifts are also possible, since the first electric motor EM1 can also provide braking support for torque at the planetary gear set.

[0043] In the first electric motor driving mode E1, the first and fifth switching elements A, E are closed, while the disconnect clutch K0 and the second, third, and fourth switching elements B, C, D are open. In the second electric motor driving mode E2, the first and fourth switching elements A, D are closed, while the disconnect clutch K0 and the second, third, and fifth switching elements B, C, E are open. In electric motor driving modes E1 and E2, the vehicle is driven exclusively by the first electric motor EM1, with the internal combustion engine VM decoupled from the main output shaft W4.

[0044] In the charging driving mode in neutral LiN, the disconnect clutch K0 and the third switching element C are closed, while the first, second, fourth, and fifth switching elements A, B, D, and E are open. The internal combustion engine VM and the first electric machine EM1 then rotate at a fixed ratio to each other. In this state, the internal combustion engine VM can be started with the first electric machine EM1, and the vehicle's electrical system can be powered by the first electric machine EM1, or the electrical energy storage device can be charged. A second electric machine EM2 on a second drive axle 102 can also be a load, as shown in Fig. Figure 1 shows that a transition from driving mode LiN to driving modes H1.3, H1.4, H2 and H3.3 is possible because the third switching element C is closed in these driving modes H1.3, H1.4, H2 and H3.3.

[0045] Furthermore, traction support can be provided by means of the second electric machine EM2 when switching operations are necessary in the transmission where the transmission output becomes unloaded. Such transitions occur, for example, when driving is initially purely electric, at least with the first electric machine EM1, and the combustion engine VM must be started using the first electric machine EM1 because it can no longer participate in the output. With the third switching element C closed, any change between the driving modes H1.3, H1.4, H2, and H3.3 is possible. The advantage of this is that the first electric machine EM1 can operate continuously as a generator, thereby supplying both the vehicle's electrical system and the second electric machine EM2 with electrical power.

[0046] Fig. Figure 4 shows a second embodiment of a transmission 1 according to the invention. The transmission 1 according to Fig. Figure 4 is shown for simplification only with the first electric machine EM1 and without the combustion engine and optional disconnect clutch, and essentially corresponds to gearbox 1 according to Fig. 2, the difference between these two embodiments being the connection of the first electric machine EM1. In this embodiment, the intermediate gear Z is meshed with the third gear 33, which is non-rotatably connected to the countershaft W3, on the third axis of rotation A3. This connects the first electric machine EM1 to the third spur gear stage ST3 via the second transmission input shaft W2 with the fixed gear F and the intermediate gear Z. Otherwise, the embodiment corresponds to the embodiment shown in Fig. 3 according to the exemplary embodiment Fig. 2, which is referenced.

[0047] Fig. Figure 5 shows a third embodiment of a transmission 1 according to the invention. The transmission 1 according to Fig. For the sake of simplicity, figure 5 is shown only with the first electric machine EM1 and without the combustion engine and optional disconnect clutch, and essentially corresponds to gearbox 1 according to Fig. 2, the difference between these two embodiments being the connection of the first electric machine EM1. In this embodiment, the intermediate gear Z is meshed with a fourth gear 14 on the first axis of rotation A1. The fourth gear 14 on the first axis of rotation A1 is non-rotatably connected to the third gear 13 on the first axis of rotation A1. Thus, the first electric machine EM1 is connected via the second transmission input shaft W2 to the fixed gear F and the intermediate gear Z to the fourth and third gears 14 and 13 on the first axis of rotation A1. Otherwise, the embodiment corresponds to the embodiment shown in the diagram. Fig. 5 according to the exemplary embodiment Fig. 2, which is referenced.

[0048] Fig. Figure 6 shows a fourth embodiment of a transmission 1 according to the invention. The transmission 1 according to Fig. Figure 6 is shown for simplification only with the first electric machine EM1 and without the combustion engine and optional disconnect clutch, and essentially corresponds to gearbox 1 according to Fig. 2, the difference between these two embodiments being the connection of the first electric machine EM1. In this embodiment, the intermediate gear Z is meshed with a fourth gear 34 on the third axis of rotation A3. The fourth gear 34 on the third axis of rotation A3 is non-rotatably connected to the countershaft W3 and thus also to the third gear 33 on the third axis of rotation A3. This connects the first electric machine EM1, via the second transmission input shaft W2 with the fixed gear F and the intermediate gear Z, to the fourth and third gears 34 and 33 on the third axis of rotation A1, which are non-rotatably connected to the countershaft W3. Otherwise, the embodiment corresponds to the embodiment shown in the above. Fig. 6 according to the exemplary embodiment Fig. 2, which is referenced.

[0049] Fig. Figure 7 shows a fifth embodiment of a transmission 1 according to the invention. The transmission 1 according to Fig. Figure 7 is shown for simplification only with the first electric machine EM1 and without the combustion engine and optional disconnect clutch, and essentially corresponds to gearbox 1 according to Fig. 6, the difference between these two embodiments being the connection of the third spur gear stage ST3 and the arrangement of the fourth switching element D. In the present embodiment, the third gear 13 on the first axis of rotation A1 is non-rotatably connected to the second element P12 of the first planetary gear set P1 and to the second gear 12 on the first axis of rotation A1, wherein the third gear 33 on the third axis of rotation A3 is designed as a loose gear and is rotatably mounted on the countershaft W3. The fourth switching element D is arranged on the third axis of rotation A3 and, in the closed state, non-rotatably connects the third gear 33 on the third axis of rotation A3 to the countershaft W3. Furthermore, the fourth and fifth switching elements D, E are combined to form a double switching element DS. Otherwise, the embodiment corresponds to the embodiment shown in the Fig. 7 according to the exemplary embodiment Fig. 6, which is referenced.

[0050] Fig. Figure 8 shows a sixth embodiment of a transmission 1 according to the invention. The transmission 1 according to Fig. Figure 8 is shown for simplification only with the first electric machine EM1 and without the combustion engine and optional disconnect clutch, and essentially corresponds to gearbox 1 according to Fig. 2, the difference between these two embodiments being the connection of the first and third spur gear stages ST1, ST3, and the arrangement of the third switching element C. In the present embodiment, the first gear 31 on the third axis of rotation A3 is rotationally fixed to the countershaft W3, with the third gear 33 on the third axis of rotation A3 being designed as a loose gear on the countershaft W3. In a closed state, the third switching element C connects the third gear 33 on the third axis of rotation A3 to the countershaft W3 and thus also to the first gear 31 on the third axis of rotation A3. Furthermore, the third and fifth switching elements C, E are combined to form a double switching element DS. Otherwise, the embodiment corresponds to the above. Fig. 8 according to the exemplary embodiment Fig. 2, which is referenced.

[0051] Fig. Figure 9 shows a drive train with a seventh embodiment of a transmission 1 according to the invention. The transmission 1 according to Fig. 9 essentially corresponds to gearbox 1 according to Fig. 2, the differences between these two embodiments being explained below. In the present case, the transmission 1 has a differential 2 arranged on the first axis of rotation A1 and a second planetary gear set P2, which is arranged in the power flow between the first planetary gear set P1 and the differential 2. The differential 2 comprises a differential input shaft 3 and two differential output shafts 4, 5. The first transmission input shaft W1 is designed as a hollow shaft, with the second differential output shaft 5 extending axially through the transmission input shaft W1 and the transmission 1.

[0052] The second planetary gear set P2 is designed as a constant-ratio stage and comprises a first element P21, which is rotationally fixed to the main output shaft W4 and thus to the planet carrier of the first planetary gear set P1; a second element P22, which is stationary on a housing G; and a third element P23, which is rotationally fixed to the differential input shaft 3. The first element P21 of the second planetary gear set P2 is designed as a sun gear, the second element P22 of the second planetary gear set P2 is designed as a ring gear, and the third element P23 of the second planetary gear set P2 is designed as a planet carrier with multiple planet gears.

[0053] The VM combustion engine is not like in Fig.2 is not shown on the first axis of rotation A1, but rather on a fourth axis of rotation A4 and is effectively connected to the first transmission input shaft W1, which is located on the first axis of rotation A1, via a traction drive 7. The traction drive 7 comprises a gear 8 non-rotatably connected to the first transmission input shaft W1, a gear 9 on the fourth axis of rotation, which can be effectively connected to the crankshaft of the internal combustion engine VM via the disconnect clutch K0 and the damping device, and a traction element 10 that engages the two gears 8 and 9 of the traction drive 7. Alternatively, the internal combustion engine VM can be effectively connected to the transmission input shaft W1 via a chain drive with several gears. The fourth axis of rotation A4 is arranged parallel to the first, second, and third axes of rotation A1, A2, and A3.The disconnect coupling K0 is arranged together with a damping device 6 on the fourth axis of rotation A4.

[0054] Furthermore, a gear can be arranged on the fourth axis of rotation A4, which is intended for connecting another electric machine, in particular a high-voltage starter-generator. For example, the high-voltage starter-generator is arranged parallel to the internal combustion engine VM and is effectively connected to the gear on the fourth axis of rotation A4 via a traction drive. Preferably, the internal combustion engine VM is started via the high-voltage starter-generator. The high-voltage starter-generator is also provided for supplying power to the vehicle's electrical system, and can also advantageously serve to support speed control of the internal combustion engine VM during coupling and gear changes. Alternatively, the high-voltage starter-generator can be omitted, making the transmission 1 more compact and cost-effective. Another alternative is that the high-voltage starter-generator can be arranged coaxially with the internal combustion engine VM. Reference sign 1 Powertrain 2 Differential 3 Differential input shaft 4 Differential output shaft 5 Differential output shaft 6 Damping device 7 Traction drive 8 Gear of the traction drive 9. Gear of the traction drive 10 traction elements of the traction element drive G Housing W1 first gearbox input shaft W2 second transmission input shaft W3 countershaft W4 main output shaft 100 vehicles 101 first drive axle 102 second drive axle R1 wheel R2 wheel R3 wheel R4 wheel VM internal combustion engine EM1 first electric machine EM2 second electric machine ST1 first spur gear stage 11 first gear on the first axis of rotation 31 first gear on the third axis of rotation ST2 second spur gear stage 12 second gear on the first axis of rotation 32 second gear on the third axis of rotation ST3 third spur gear stage 13 third gear on the first axis of rotation 33 third gear on the third axis of rotation F fixed wheel Z intermediate gear 14 fourth gear on the first axis of rotation 34 fourth gear on the third axis of rotation A first switching element B second switching element C third switching element The fourth switching element E fifth switching element K0 disconnect coupling DS double switching element A1 first axis of rotation A2 second axis of rotation A3 third axis of rotation A4 fourth axis of rotation P1 first planetary gear set P11 first element of the first planetary gear set P12 second element of the first planetary gear set P13 third element of the first planetary gear set P2 second planetary gear set P21 first element of the second planetary gear set P22 second element of the second planetary gear set P23 third element of the second planetary gear set

Claims

[1] Transmission (1) for a drive train of a vehicle (100), comprising • a first transmission input shaft (W1) arranged on a first rotational axis (A1) for connecting an internal combustion engine (VM), • a second transmission input shaft (W2) arranged on a second rotational axis (A2) for connecting a first electric machine (EM1), • a countershaft (W3) arranged on a third rotational axis (A3) with a first gear (31), a second gear (32) and a third gear (33), wherein the first gear (31) on the third rotational axis (A3) meshes with a first gear (11) on the first rotational axis (A1) and forms a first spur gear stage (ST1), wherein the second gear (32) on the third rotational axis (A3) meshes with a second gear (12) on the first rotational axis (A1) and forms a second spur gear stage (ST2), wherein the third gear (33) on the third rotational axis (A3) meshes with a third gear (13) on the first rotational axis (A1) and forms a third spur gear stage (ST3), • at least one first planetary gear set (P1) arranged on the first rotational axis (A1) and designed as a superposition gear with a first element (P11), a second element (P12) and a third element (P13), • a main output shaft (W4) arranged on the first rotational axis (A1) and connected in a rotationally fixed manner to the third element (P13) of the first planetary gear set (P1), • a first switching element (A), a second switching element (B), a third switching element (C), a fourth switching element (D) and a fifth switching element (E), wherein the first switching element (A) in the closed state connects two of the three elements (P11, P12, P13) of the first planetary gear set (P1) in a rotationally fixed manner, wherein the second switching element (B) in the closed state connects the first and second gears (31, 32) on the third rotation axis (A3) in a rotationally fixed manner, wherein the third switching element (C) in the closed state connects the first or third gear (31, 33) on the third rotation axis (A3) to the countershaft (W3) in a rotationally fixed manner, wherein the fourth shift element (D) in the closed state connects the second element (P12) of the first planetary gear set (P1), the second transmission input shaft (W2) and the countershaft (W3) to one another in a drivingly effective manner, wherein the fifth switching element (E) in the closed state connects the second gear (32) on the third rotation axis (A3) to the countershaft (W3) in a rotationally fixed manner, wherein the first, second and third axes of rotation (A1, A2, A3) are arranged axially parallel to one another. [2] Transmission (1) according to claim 1, wherein the first gear (11) is connected in a rotationally fixed manner to the first element (P11) of the first planetary gear set (P1) on the first rotation axis (A1). [3] Transmission (1) according to one of the preceding claims, wherein the second gear (12) is connected in a rotationally fixed manner on the first axis of rotation (A1) to the second element (P12) of the first planetary gear set (P1). [4] Transmission (1) according to one of the preceding claims, wherein the third gear (13) on the first rotational axis (A1) is designed as a loose wheel and can be connected in a rotationally fixed manner to the second element (E12) of the first planetary gear set (P1) by means of the fourth switching element (D). [5] Transmission (1) according to one of claims 1 to 3, wherein the third gear (13) on the first rotational axis (A1) is connected in a rotationally fixed manner to the second element (P12) of the first planetary gear set (P1), wherein the third gear (33) on the third rotational axis (A3) is designed as a loose wheel and is connected in a rotationally fixed manner to the countershaft (W3) in the closed state of the fourth shifting element (D). [6] Transmission (1) according to one of claims 1 to 4, wherein the first and fourth switching elements (A, D) are arranged on the first rotational axis (A1), wherein the second, third and fifth switching elements (B, C, E) are arranged on the third rotational axis (A3). [7] Transmission (1) according to one of claims 1 to 3 and 5, wherein the first switching element (A) is arranged on the first rotational axis (A1), wherein the second, third, fourth and fifth switching elements (B, C, D, E) are arranged on the third rotational axis (A3). [8] Transmission (1) according to one of the preceding claims, further comprising a differential (2) arranged on the first rotational axis (A1) with a differential input shaft (3) and two differential output shafts (4, 5), wherein the differential input shaft (3) is at least indirectly connected to the main output shaft (W4). [9] Transmission (1) according to claim 8, further comprising a second planetary gear set (P2) arranged on the first axis of rotation (A1) and arranged in the power flow between the first planetary gear set (P1) and the differential (2), wherein the second planetary gear set (P2) has a first element (P21) which is non-rotatably connected to the main output shaft (W4), a second element (P22) which is stationary, and a third element (P23) which is non-rotatably connected to the differential input shaft (3). [10] Transmission (1) according to one of the preceding claims, wherein the second transmission input shaft (W2) has a fixed gear (F) which meshes with an intermediate gear (Z), wherein the intermediate gear (Z) is further meshed with one of the two gears (13, 33) forming the third spur gear stage (ST3). [11] Transmission (1) according to one of claims 1 to 9, wherein the second transmission input shaft (W2) has a fixed gear (F) which is in meshing engagement with an intermediate gear (Z), wherein the intermediate gear (Z) is further in meshing engagement with a fourth gear (14) on the first rotational axis (A1), which is connected in a rotationally fixed manner to the third gear (13) on the first rotational axis (A1). [12] Transmission (1) according to one of claims 1 to 9, wherein the second transmission input shaft (W2) has a fixed gear (F1) which meshes with an intermediate gear (Z), wherein the intermediate gear (Z) is further meshed with a fourth gear (34) on the third rotational axis (A3) which is connected in a rotationally fixed manner to the countershaft (W3). [13] Transmission (1) according to one of the preceding claims, wherein the second and third switching elements (B, C) are combined to form a double switching element (DS). [14] Transmission (1) according to one of the preceding claims, further comprising a switching element designed as a separating clutch (K0) which is designed to decouple the first transmission input shaft (W1) from the internal combustion engine (VM). [15] Drive train comprising an internal combustion engine (VM), at least one first electric machine (EM1) and a transmission (1) according to one of claims 1 to 14, wherein the internal combustion engine (VM) and the first electric machine (EM1) are arranged axially parallel to one another.

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