Gearbox for a motor vehicle, motor vehicle drive train having a gearbox, and method for operating a gearbox

Abstract

The present invention relates to a transmission (4), comprising a motor (30), a first input shaft (10), a second input shaft (11), and a countershaft (12). A first spur gear stage (20) is provided, having a fixed gear (23) mounted on the first input shaft (10) and a movable gear (24) meshing with it. The movable gear is rotatably supported on the countershaft (12) and can be fixed to the countershaft (12) by a first switching element (S2). A second spur gear stage (19) is also provided, having a fixed gear (26) mounted on the second input shaft (11) and a movable gear (25) meshing with it. The movable gear is rotatably supported on the countershaft (12) and can be fixed to the countershaft (12) by a second switching element (S4). Furthermore, the movable gear (24) of the first spur gear stage (20) and the movable gear (25) of the second spur gear stage (19) are non-rotatably connected to each other by a third switching element (S3). In addition, a planetary group (31) is provided, the second element (35) of which is non-rotatably connected to the second input shaft (11) and the third element (36) of which is coupled to the rotor (32) of the motor (30). The first element (34) of the planetary group (31) can be fixed by operating the fourth switching element (B) and the two elements (34, 35, 36) of the planetary group (31) can be non-rotatably connected to each other by closing the fifth switching element (K).

Description

Technical Field

[0001] This invention relates to a transmission for a motor vehicle, the transmission comprising a motor, a first input shaft, a second input shaft, and a countershaft permanently connected to an output side. The countershaft includes a first spur gear stage having a fixed gear mounted on the first input shaft and a movable gear meshing with the fixed gear. The movable gear is rotatably supported on the countershaft and can be fixed to the countershaft by a first switching element. A second spur gear stage is also provided, having a fixed gear mounted on a second input shaft and a movable gear meshing with the fixed gear. The movable gear is rotatably supported on the countershaft and can be fixed to the countershaft by a second switching element. The movable gears of the first and second spur gear stages are non-rotatably connected to each other by a third switching element. Furthermore, this invention relates to a motor vehicle drivetrain having the aforementioned transmission and a method for operating the transmission. Background Technology

[0002] Multi-speed transmissions are known in motor vehicles, in which multiple different gear ratios can be switched as gears by operating corresponding switching elements, preferably automatically. The transmission is used to suitably supply traction to the driving mechanism of the motor vehicle according to different standards. In transmissions used in hybrid vehicles, the aforementioned transmission is often combined with one or more electric motors, which can be connected in different ways within the transmission to achieve different operating modes, such as pure electric driving.

[0003] A transmission is known from DE 10 2013 211 591 A1, which has a first input shaft and a second input shaft coaxial with each other. Each input shaft can be non-rotatably connected to a shaft coaxial with the input shaft and non-rotatably connected to the rotor of a motor by operating a corresponding switching element. Furthermore, two countershafts are provided, their axes parallel to each other and also parallel to the axis of the input shaft. The transmission includes multiple spur gear stages, each consisting of a fixed gear and a movable gear meshing with the corresponding fixed gear. The fixed gears of each spur gear stage are non-rotatably mounted on one of the input shafts, while the corresponding movable gears are rotatably supported on one of the countershafts and fixed thereby by a corresponding switching element. Furthermore, two movable gears rotatably supported side-by-side axially on a countershaft can be non-rotatably connected to each other by a switching element. Summary of the Invention

[0004] Based on the prior art described above, the present invention aims to provide a transmission in which a higher number of gears can be switched in a compact structure, and a motor is connected in a suitable manner.

[0005] This task is solved by a transmission, a motor vehicle drivetrain, and a method for operating the transmission.

[0006] According to the present invention, the transmission includes a motor, a first input shaft, a second input shaft, and a countershaft permanently connected to the output side. A first spur gear stage is provided, having a fixed gear mounted on the first input shaft and a movable gear meshing with the fixed gear. The movable gear is rotatably supported on the countershaft and can be fixed to the countershaft by a first switching element. A second spur gear stage is also provided, having a fixed gear mounted on the second input shaft and a movable gear meshing with the fixed gear. The movable gear is rotatably supported on the countershaft and can be fixed to the countershaft by a second switching element. Here, the movable gears of the first and second spur gear stages are non-rotatably connected to each other by a third switching element.

[0007] In the context of this invention, "shaft" should be understood as a rotatable component of a transmission through which force flow can be transmitted between components when necessary, with simultaneous operation of corresponding switching elements. The corresponding shaft can connect components to each other axially or radially, or both. Therefore, the corresponding shaft can also be an intermediate component, through which the corresponding components are connected, for example, radially.

[0008] In this invention, "axial" refers to the orientation along the longitudinal central axis of the transmission, with the axis of rotation of the transmission shaft oriented parallel to this longitudinal central axis. "Radial" should be understood as the orientation along the diameter of the corresponding component of the transmission, particularly the corresponding shaft.

[0009] The transmission according to the invention has a first input shaft and a second input shaft, which are preferably coaxial with each other. In particular, each input shaft is assigned to a sub-transmission of the transmission, through which force flow can be transmitted from its respective input shaft to a countershaft and thus to an output side permanently coupled thereto. The countershaft is arranged parallel to the axes of the two input shafts and can be coupled to the first input shaft via a first spur gear stage by operating a first switching element and to the second input shaft via a second spur gear stage by operating a second switching element. Within the scope of the invention, one or more additional, parallel-axis countershafts may be provided in addition to the aforementioned countershaft if necessary. However, it is particularly preferred that the transmission according to the invention has exactly one countershaft.

[0010] The first spur gear stage consists of a fixed gear and a movable gear meshing with the fixed gear. The fixed gear is non-rotatably mounted on the first input shaft, while the movable gear of the first spur gear stage is rotatably supported on a countershaft and can be fixed to the countershaft by closing a first switching element. This results in the first input shaft and the countershaft being coupled to each other through the first spur gear stage. The second spur gear stage also consists of a fixed gear and a movable gear meshing with the fixed gear. The fixed gear is non-rotatably mounted on the second input shaft, while the movable gear of the second spur gear stage is rotatably supported on a countershaft and can be fixed to the countershaft by operating a second switching element. Therefore, closing the second switching element results in the coupling of the second input shaft and the countershaft through the second spur gear stage.

[0011] Besides their respective fixation on the countershaft, the moving gears of the first and second spur gear stages can also be non-rotatably connected to each other, thereby coupling the input shafts together via the two spur gear stages. Correspondingly, a sub-transmission having the other input shaft can be accessed from a sub-transmission having one input shaft.

[0012] In the transmission according to the invention, the countershaft is permanently coupled to the output side. Preferably, a differential coupling is also established here via the output side of the transmission, positioned parallel to the axis of the input shaft of the transmission. Here, the output side is preferably located axially in or near the connection point where the transmission according to the invention is connected to or can be connected to an upstream drive machine in the installed state. However, in principle, the output side can also be located in the region between the axial ends of the transmission. This arrangement is particularly suitable for use in motor vehicles having a transmission system oriented transversely to the direction of travel of the vehicle.

[0013] Alternatively, the output side of the transmission can, in principle, be located at the axial end of the transmission opposite to the aforementioned connection point. Here, the drive end and output end of the transmission are specifically located at opposite axial ends of the transmission. A transmission designed in this way is suitable for use in motor vehicles having a drivetrain oriented along the direction of travel of the vehicle.

[0014] The present invention now includes the following technical teachings: a planetary gear system is provided, having a first element, a second element, and a third element in the form of a sun gear, a planet carrier, and a ring gear, wherein the second element is non-rotatably connected to a second input shaft and the third element is coupled to the rotor of a motor. Furthermore, the first element of the planetary gear system can be fixed by operating a fourth switching element, and the two elements of the planetary gear system can be non-rotatably connected to each other by closing a fifth switching element. In other words, in the transmission according to the invention, in addition to the first and second spur gear stages, a planetary gear system is provided, having a sun gear, a planet carrier, and a ring gear as elements. One of these elements is non-rotatably connected to the second input shaft, while the other element is connected to the rotor of a motor. Furthermore, two switching elements are assigned to the planetary gear system, one of which, when operated, causes the remaining elements of the planetary gear system to be fixed, thereby preventing subsequent rotational movement of those elements. The other switching element connects the two elements of the planetary gear system in the closed state, resulting in interlocking of the planetary gear system.

[0015] This design of the transmission has the following advantages: the motor can be coupled to the second input shaft via the planetary gear system, thus allowing the motor to obtain the achievable gear ratios of the sub-transmission allocated to the second input shaft. Therefore, the motor can directly utilize these gear ratios of the sub-transmission by engaging the force flow between the second input shaft and the countershaft. Furthermore, since the moving gears of the first and second spur gear stages can be interconnected via a third switching element, and thus the two input shafts are also coupled, it is possible that force flow transmission can also be achieved via the sub-transmission allocated to the first input shaft when the motor is engaged. By using the planetary gear system and its different switching states—i.e., the fixation of the first element on one hand and the interlocking of the planetary gear system on the other—the number of gears available to the motor can be increased by additionally changing the achievable gear ratios between the second input shaft and the output side via the downstream planetary gear system, thus doubling the number of gear ratios available to the motor. In summary, this allows for suitable motor engagement with a higher number of achievable gears. This can be achieved with low manufacturing costs and a compact structure.

[0016] Although the motor can utilize multiple different gears in DE 10 2013 211 591 A1, this requires a large number of spur gear stages and switching elements, which correspondingly increases manufacturing costs and space requirements.

[0017] The arrangement of the electric motor makes the transmission according to the invention suitable for use in hybrid or electric vehicles. Here, the rotor of the motor can be coupled to the second input shaft via an intermediate planetary segment. Within the scope of the invention, the motor preferably operates as a generator on one hand and as an electric motor on the other. The “coupling” of the motor rotor to the third element of the planetary segment should be understood in the sense of the invention as a connection between them, resulting in a constant speed dependence between the motor rotor and the third element of the planetary segment. It is particularly preferred that the transmission here has exactly one electric motor.

[0018] The first, second, third, and fifth switching elements are currently clutches, which, when operated, respectively connect the directly attached components of the transmission to each other in a non-rotatable manner. In the case of the first switching element, this results in a non-rotatable connection between the moving gear of the first spur gear stage and the countershaft. The second switching element, when operated, causes a non-rotatable connection between the moving gear of the second spur gear stage and the countershaft. Conversely, the third switching element, when operated, ensures a non-rotatable connection between the moving gears of the first and second spur gear stages. The fifth switching element connects two planetary-level elements to each other in a non-rotatable manner; this could be the first and second planetary-level elements, or the first and third elements, or the second and third elements.

[0019] Conversely, the fourth switching element is implemented as a brake, which, when operated, ensures the fixation of the component directly connected to it—in this case, the planetary-level first element. Fixation is specifically achieved by connecting the component to a non-rotatable structural element, preferably the transmission housing, a portion thereof, or a component to which it is non-rotatable.

[0020] In a planetary gear set, the first element is preferably a sun gear, the second element is a planet carrier when the planetary gear set is a negative planetary gear set and a ring gear when the planetary gear set is a positive planetary gear set, and the third element is a ring gear when the planetary gear set is a negative planetary gear set and a planet carrier when the planetary gear set is a positive planetary gear set.

[0021] In a negative planetary gear set, the planet carrier supports at least one, but preferably multiple, planetary gears, which mesh with both the sun gear and the ring gear. According to the invention, in this planetary embodiment, the first element is constituted by the ring gear, the second element by the planet carrier, and the third element by the ring gear.

[0022] Conversely, if the planet carrier is a positive planetary gear set, in which the planet carrier rotatably supports and guides at least one pair of planetary gears, one of which meshes with a sun gear and another with a ring gear, and the planetary gears mesh with each other, then the first element is again composed of a sun gear. However, unlike a negative planetary gear set, the second element is a ring gear and the third element is the planet carrier. Furthermore, compared to a negative planetary gear set, the fixed gear ratio of the planetary gear set will increase by 1.

[0023] Furthermore, according to one embodiment of the invention, a third spur gear stage having a fixed gear and a movable gear, and a sixth switching element are also provided. When operated, the sixth switching element fixes the movable gear of the third spur gear stage, thereby coupling the first input shaft and the countershaft together. In addition to the first spur gear stage, within the scope of this embodiment, it is therefore possible that the first input shaft and the countershaft are directly coupled through the third spur gear stage, for which the movable gear of the third spur gear stage would be fixed by operating the sixth switching element. In the third spur gear stage, the fixed gear can be non-rotatably mounted on the first input shaft, while the movable gear of the third spur gear stage is rotatably supported on the countershaft. Alternatively, the fixed gear of the third spur gear stage is mounted on the countershaft, while the movable gear meshing with it is rotatably mounted on the first input shaft.

[0024] In the transmission according to the invention, it is particularly preferred that the direct coupling between the first input shaft and the countershaft can only be achieved through the first and third spur gear stages, while the direct coupling between the second input shaft and the countershaft can only be achieved through the second spur gear stage. Therefore, in this case, exactly three spur gear stages are provided between the input shaft and the countershaft.

[0025] In an extended embodiment of the foregoing implementation, a first gear is formed between the first input shaft and the output side by closing the sixth switching element and transmitting force via the third spur gear stage. A second gear is then engaged between the first input shaft and the output side by operating the first switching element, with force transmission occurring via the first spur gear stage.

[0026] A third gear is formed between the second input shaft and the output side by closing the third and sixth switching elements, through force flow transmission via the second, first, and third spur gear stages. This third gear, operating between the second input shaft and the output side, is therefore designed as a detour gear, in which force flow is transmitted from the second input shaft via the second and first spur gear stages to the first input shaft and from there via the third spur gear stage to the countershaft. Furthermore, in the first variant, a fourth gear is formed between the second input shaft and the output side by operating the second switching element, and in the second variant, the fourth gear is engaged between the second input shaft and the output side by closing the first and third switching elements. In both cases, force flow transmission occurs via the second spur gear stage, and in the second variant, the movable gear of the second spur gear stage is indirectly fixed to the countershaft via the movable gear of the first spur gear stage.

[0027] Since the motor can be coupled to the second input shaft via a planetary gear, the motor can utilize the gears that operate between the second input shaft and the output side. As described above, by fixing the first element of the planetary gear and by interlocking the planetary gear, the number of gears that can be effectively utilized by the motor is doubled. Pure electric driving can be achieved here, and the vehicle can be driven forward or backward depending on the introduced direction of rotation. In generator-type operation, the motor can also be used for braking (regenerative braking) of the vehicle when one of the gears is engaged.

[0028] According to one design possibility of the invention, a first input shaft and a second input shaft are coaxially arranged with a drive shaft configured to connect the transmission to the drive mechanism of the motor vehicle. This drive shaft is non-rotatably connected to the first input shaft via a first switching clutch and non-rotatably connected to the second input shaft via a second switching clutch. Therefore, in this design possibility, both input shafts and thus the two sub-transmissions of the transmission can also be connected to the drive shaft, through which a connection to the upstream drive mechanism of the motor vehicle is established or can be established in the transmission's installed state. In this regard, gears that can be engaged between a single input shaft and the output side can also be used for drive via the upstream drive mechanism by additionally closing the corresponding switching clutch and the resulting non-rotatable connection between the drive shaft and the corresponding input shaft.

[0029] The corresponding switching clutch can be implemented as a force-locking switching clutch, and a single switching clutch is preferably a friction clutch operating in wet or dry conditions. However, alternatively, a plate-type switching element can also be considered. Furthermore, the corresponding switching clutch can also be a form-locking switching clutch, which is particularly implemented here as a lock-up synchronizing device or an asynchronous claw clutch.

[0030] Particularly preferred is that, when driving the motor vehicle via the upstream drive mechanism, the drive shaft alternately switches between gears that can be realized between the first input shaft and the output side, and between the second input shaft and the output side, respectively, so that during continuous gear shifting, the drive shaft alternately engages with the first input shaft and the second input shaft via their respective switching clutches. Since the motor may be coupled to the second input shaft via a planetary coupling, the motor can support traction in each gear that can be formed between the output side and the second input shaft during continuous gear shifting. This allows the upstream drive mechanism to shift gears without load.

[0031] Furthermore, the transmission according to the invention can operate in charging or starting mode, so as to charge the electrical energy storage device by the motor in the first case in generator-type operation of the motor, and to start the upstream drive machine, which is in particular implemented as an internal combustion engine, in the second case. In a variant of the invention, a second switching clutch and a fourth or fifth switching element are operated for this purpose. Thus, the second input shaft is non-rotatably connected to the drive shaft on which the connection to the upstream drive machine is established in the installed state. Furthermore, the motor is coupled to the second input shaft via a planetary gear, which is done at a gear ratio through the planetary gear when the fourth switching element is operated. Therefore, at a suitable gear ratio through the planetary gear, a higher rotational speed of the motor rotor can be advantageously achieved in charging mode. Conversely, when the fifth switching element is operated, the motor rotor and the second input shaft are directly coupled to each other via an interlocked planetary gear.

[0032] Alternatively, starting or charging operation can be achieved by closing the first switching clutch, as well as the third and fourth switching elements. This is because in this case, coupling between the input shafts is established by closing the third switching element, thus indirectly coupling the motor to the drive shaft and also to the upstream drive machine via the first input shaft. Similar to the above description, charging in generator-type operation or starting in motor-type operation of the motor can also be achieved here. By operating the fourth switching element in parallel with the third switching element, which is done via a planetary gear ratio, a higher rotor speed relative to the upstream drive machine can be advantageously achieved, especially during charging operation. Alternatively, the closing of the first switching clutch can also be combined with the operation of the third and fifth switching elements, thus coupling the motor rotor to the second input shaft via an interlocked planetary gear ratio.

[0033] In an extended embodiment of the invention, a braking device coupled to the drive shaft is also provided. This advantageously supports speed synchronization during gear shifting, particularly when the one or more switching elements to be engaged exist as asynchronous form-locking switching elements. This is because the braking device coupled to the drive shaft can support the upstream drive machine when the speeds are matched. Thus, during upshifting, the upstream drive machine can be braked to a lower speed level, while during downshifting, the braking device is operated just before reaching the desired synchronization speed, in order to obtain a smaller speed gradient before operating the corresponding switching element. Furthermore, during downshifting, the upstream drive machine must be accelerated to a correspondingly higher speed level. A force-locking brake and especially a friction brake are particularly preferred here, but within the scope of the invention, it is also contemplated that the braking device be implemented as an additional motor. In this case, in addition to braking, the braking device can also support the acceleration of the upstream drive machine by operating the additional motor as an electric motor.

[0034] In a variation of the invention, the braking device is offset from the drive shaft axis and coupled to the drive shaft via a transmission stage. This has the advantage of enabling a modular structure for the transmission, in which different embodiments of the braking device can be connected. Within the scope of the invention, the transmission stage can be a spur gear stage or a traction drive mechanism, the latter being particularly a chain drive mechanism. Alternatively, the braking device is coaxially arranged with the drive shaft and connected to the drive shaft in a non-rotatable manner.

[0035] According to one embodiment of the invention, the motor is coaxially arranged with the second input shaft, and the rotor is non-rotatably connected to the third element of the planetary stage. A compact structure can be achieved through the coaxial arrangement of the motor with the second input shaft and therefore also with the planetary stage. Particularly preferred is that the planetary stage is axially positioned at the height of the motor and radially positioned inside the motor. Thus, the motor and the planetary stage are nested within each other. However, alternatively, within the scope of the invention, it is also conceivable that the rotor of the motor is coupled to the third element of the planetary stage via at least one intermediate transmission stage. The at least one transmission stage can be either a planetary stage or a spur gear stage. Furthermore, as an alternative, the motor can, in principle, be offset from the axis of the second input shaft and also from the axis of the planetary stage, in which case the coupling of the motor's rotor to the third element of the planetary stage is accomplished via at least one intermediate transmission stage.

[0036] In an extended embodiment of the invention, the single switching element is a form-locking switching element, particularly a claw-type switching element. Alternatively, the form-locking switching element can also be a locking synchronization device. Form-locking switching elements have the advantage of having only low drag torque in the open state and correspondingly high efficiency. Alternatively, the single switching element can also be a force-locking switching element, such as a plate-type switching element, which can advantageously switch to the operated state even under load. Particularly preferred are the first, second, third, and, if necessary, sixth switching elements, each implemented as asynchronous claw-type switching elements. The fourth and fifth switching elements are preferably force-locking switching elements, and particularly plate-type switching elements, within the scope of the invention. However, alternatively, within the scope of the invention, it is also conceivable that the fourth switching element be implemented as a form-locking switching element, and particularly as an asynchronous claw-type switching element, while the fifth switching element is a force-locking switching element.

[0037] It is particularly preferred that the second and third switching elements, when implemented as form-locking switching elements, are combined into a switching device with an operating mechanism. Here, by operating the device from the neutral position, both the second and third switching elements can be switched to their respective operated states. Furthermore, if a third spur gear stage and therefore a sixth switching element are also present, then, instead of or supplementing the above-described scheme, the first and sixth switching elements are also combined into a switching device, whose operating mechanism, by operating the device from the neutral position, can switch both the first and sixth switching elements to their respective operated states.

[0038] According to one design possibility of the invention, the countershaft is coupled to the output side via a spur gear stage. This allows the drive motion transmitted to the countershaft to be further transmitted to the output side of the transmission. However, alternatively, within the scope of the invention, it is also conceivable that the output side is constructed at one axial end of the countershaft, so that the countershaft almost constitutes the output shaft of the transmission. Furthermore, when the countershaft is coupled to the output side via a spur gear stage, the spur gear on the output side can be located on the output shaft or can be constructed as a drive crown gear of the differential parallel to its axis.

[0039] In the extended design possibilities described above, one spur gear in the spur gear stage coupling the countershaft and the output side is also a fixed gear in one of the spur gear stages coupling the countershaft and one of the input shafts. Thus, the drive motion transmitted to the countershaft can be transmitted through the additional spur gear stage, requiring only one additional spur gear. This maintains low manufacturing costs.

[0040] A starting element, such as a torque converter or friction clutch, can be connected upstream of the transmission. This starting element can also be an integral part of the transmission and used to initiate the starting process by enabling a slip speed between the drive machine, implemented as an internal combustion engine, and the drive shaft of the transmission. Here, one of the transmission's switching elements or switching clutches can also be configured as such a starting element, specifically a friction switching element. However, a drive shaft configuration for direct connection to the upstream drive machine is particularly preferred, i.e., in the absence of an intermediate starting element. Furthermore, in principle, a freewheel mechanism for the transmission housing or other shafts can be provided on each shaft of the transmission.

[0041] The transmission according to the invention is particularly used as part of the powertrain of a motor vehicle, specifically a hybrid or electric vehicle, and is disposed between the drive mechanism of the motor vehicle, which is constructed of an internal combustion engine or an electric motor, and other subsequent components of the powertrain in the direction of force flow to the drive wheels of the motor vehicle. The drive shaft of the transmission is permanently and non-rotatably coupled to the crankshaft of the internal combustion engine, or can be connected to the crankshaft via an intermediate disengagement clutch or starting element. A torsional damper can also be disposed between the internal combustion engine and the transmission. In the case where the drive mechanism is an electric motor, a direct, non-rotatably coupled connection between the drive shaft and the rotor of the electric motor can also be achieved. On the output side, the transmission is preferably coupled to the differential of the drive axle of the motor vehicle within the powertrain, but it can also be connected to a longitudinal differential, through which the distribution to the multiple driven axles of the motor vehicle is achieved. The differential or longitudinal differential can be disposed in a common housing with the transmission. The torsional damper can also be integrated into this housing.

[0042] In the sense of this invention, the phrase "connected," "coupled," or "interconnected" to mean that the two structural elements of the transmission are permanently coupled, so that they cannot rotate independently of each other. In this respect, no switching element is provided between these structural elements—which may be planetary-level elements and / or spur gears of the spur gear stage and / or shafts and / or non-rotatable structural elements of the transmission—but rather the corresponding structural elements are rigidly coupled to each other.

[0043] Conversely, if a switching element is provided between two structural elements of the transmission, these structural elements are not permanently coupled to each other without relative rotation, but rather connected without relative rotation by operating the intermediate switching element. In the context of this invention, "operating the switching element" means switching the relevant switching element to a closed state and thus keeping the rotational motion of the structural elements directly connected to it consistent. When the relevant switching element is designed as a form-locking switching element, the structural elements directly connected to each other without relative rotation operate at the same speed, while in the case of a force-locking switching element, a speed difference may exist between the structural elements after operating the same switching element. However, this desired or undesirable state is also referred to within the scope of this invention as a non-relative rotational connection of the corresponding structural elements via the switching element.

[0044] This invention is not limited to the combination of features of the given independent claim or its dependent claims. Furthermore, the various features may also be combined with each other, provided that they are disclosed by the claims, the following description of preferred embodiments of the invention, or directly by means of the drawings. The use of reference numerals to the drawings in the claims should not limit the scope of the claims. Attached Figure Description

[0045] The following advantageous embodiments of the invention are illustrated in the accompanying drawings. The drawings are as follows:

[0046] Figure 1 A schematic diagram of a motor vehicle transmission system is shown;

[0047] Figures 2 to 10 Show respectively Figure 1 A partial schematic diagram of a motor vehicle transmission system, wherein each motor vehicle transmission system has a transmission corresponding to one embodiment of the present invention;

[0048] Figure 11 Show Figures 2 to 10 An exemplary shift diagram of the transmission; and

[0049] Figure 12 Show in tabular form the data based on Figures 2 to 10 One of the different operating modes of a motor vehicle's transmission system is the gearbox. Detailed Implementation

[0050] Figure 1A schematic diagram of the powertrain 1 of a hybrid vehicle is shown. In the powertrain 1, the internal combustion engine 2 is connected to the transmission 4 via a torsional damper 3 located in the middle. Downstream of the transmission 4, on the output side, a differential 5 is connected, through which drive power is distributed to the drive wheels 6 and 7 of the vehicle's drive axle. The transmission 4 and the torsional damper 3 are combined in a common transmission housing 8 of the transmission 4, and the differential 5 may also be integrated into this transmission housing. Furthermore, as shown from... Figure 1 It can be seen that the internal combustion engine 2, torsional damper 3, transmission 4, and differential 5 are oriented laterally to the direction of travel of the motor vehicle.

[0051] Depend on Figure 2 Learned Figure 1 This is a partial schematic diagram of a motor vehicle transmission system 1 in the region of a transmission 4, constructed according to a first embodiment of the invention. The transmission 4 includes a drive shaft 9, a first input shaft 10, and a second input shaft 11, which are coaxially arranged with each other. The drive shaft 9 is non-rotatably connected to a torsional damper 3 and is implemented as a solid shaft, extending substantially along the entire axial structural length of the transmission 4. The first input shaft 10 and the second input shaft 11 exist as hollow shafts, each overlapping a segment of the drive shaft 9 axially and arranged radially around the drive shaft.

[0052] The drive shaft 9 can be non-rotatably connected to each of the input shafts 10 and 11 via a switching clutch K1 or K2 located in the middle. When switching clutch K1 is closed, it non-rotatably connects the drive shaft 9 to the first input shaft 10, while the closed state of switching clutch K2 results in a non-rotatable connection between the drive shaft 9 and the second input shaft 11. Switching clutches K1 and K2 are respectively implemented as form-locking switching clutches and, in particular, exist as asynchronous claw clutches.

[0053] In addition to drive shaft 9 and input shafts 10 and 11 Figure 2 The transmission 4 also has a countershaft 12 and an output shaft 13, which are implemented as solid shafts and are offset from the drive shaft 9 and the input shafts 10 and 11, and also from each other. Here, the output shaft 13 forms the output side 14 of the transmission 4, where a coupling with the subsequent differential 5 is also established within the vehicle drivetrain 1.

[0054] The secondary shaft 12 and the output shaft 13 are permanently coupled by a spur gear stage 15 consisting of a spur gear 16 and a spur gear 17. The spur gear 16 is mounted on the secondary shaft 12 and meshes with the spur gear 17, which is mounted on the output shaft 13.

[0055] The transmission 4 also includes multiple spur gear stages 18, 19, and 20. The first input shaft 10 is coupled to a countershaft 12 parallel to the axis via the spur gear stages 18 and 20, respectively, while the second input shaft 11 is coupled to the countershaft 12 via the spur gear stage 19. In this respect, the spur gear stages 18 and 20 are part of one sub-transmission of the transmission 4, to which the first input shaft 10 is assigned. The spur gear stage 19 is part of another sub-transmission of the transmission 4, to which the second input shaft 11 is assigned.

[0056] The spur gear stage 18 consists of a fixed gear 21 and a movable gear 22, which mesh with each other. The fixed gear 21 is fixed on the first input shaft 10 in a non-rotatable manner. The movable gear 22 is rotatably supported on the countershaft 12 and can be fixed on the countershaft 12 by a switching element S1, so that the spur gear stage 18 thus couples the first input shaft 10 and the countershaft 12 together.

[0057] A spur gear stage 20 is also disposed between the first input shaft 10 and the countershaft 12 and consists of a fixed gear 23 and a movable gear 24. The fixed gear 23 and the movable gear 24 are permanently meshed with each other. The fixed gear 23 is fixedly mounted on the first input shaft 10 without relative rotation, while the movable gear 24 is rotatably supported on the countershaft 12 and can be fixed to the countershaft 12 by means of a switching element S2. This fixing thus results in the coupling of the first input shaft 10 and the countershaft 12 through the spur gear stage 20.

[0058] Furthermore, the movable gear 24 of the spur gear stage 20 can also be non-rotatably connected to the axially adjacent movable gear 25, which is part of the spur gear stage 19, via the switching element S3. Here, the movable gear 25 of the spur gear stage 19 is also rotatably supported on the countershaft 12 and permanently meshes with the fixed gear 26 of the spur gear stage 19, which is non-rotatably mounted on the second input shaft 11. The closure of the switching element S3, based on the resulting non-rotatable connection of the movable gears 24 and 25, results in the coupling of the two input shafts 10 and 11 via the spur gear stages 19 and 20. Alternatively, the second input shaft 11 can also be coupled to the countershaft 12 via the spur gear stage 19, in which the movable gear 25 is fixed to the countershaft 12 via the switching element S4.

[0059] In the current case, switching elements S1 to S4 are respectively implemented as form-locking switching elements, and each individual switching element S1, S2, S3, or S4 is an asynchronous claw clutch. Furthermore, switching elements S1 and S2 are combined into a switching device 27, whose operating mechanism, starting from the neutral position, can switch both switching elements S1 and S2 to their respective operated states. Similarly, switching elements S3 and S4 are combined into a switching device 28, whose operating mechanism, starting from the neutral position, can switch both switching elements S3 and S4 to their respective operated states. Finally, the two switching clutches K1 and K2 also jointly form a switching device 29 with a common operating mechanism, which, starting from the neutral position, can move both the first switching clutch K1 and the second switching clutch K2 to their respective closed states.

[0060] The transmission 4 also includes a motor 30 and planetary gears 31. The motor 30 includes a rotor 32 and a stator 33, with the stator permanently fixed to the transmission housing 8 of the transmission 4. The motor 30 can function as both a generator and an electric motor. The planetary gears 31 include a first element 34, a second element 35, and a third element 36, where the first element 34 is a sun gear 37, the second element 35 is a planet carrier 38, and the third element 36 is a ring gear 39.

[0061] Planetary gear set 31 is currently implemented as a negative planetary gear set, in which a planet carrier 38 rotatably supports and guides a plurality of planetary gears 40, which mesh not only with the sun gear 37 but also with the ring gear 39. However, within the scope of the invention, planetary gear set 31 can also be implemented in principle as a positive planetary gear set, wherein the planet carrier rotatably supports and guides at least one pair of planetary gears, one of which meshes with the sun gear and one with the ring gear; furthermore, the planetary gears of the at least one pair mesh with each other. Compared to implementing it as a positive planetary gear set, the connections of the ring gear and the planet carrier should be interchanged, and the fixed transmission ratio of the planetary gear set will increase by 1.

[0062] In planetary gear 31, the second element 35 is non-rotatably connected to the second input shaft 11, while the third element 36 of planetary gear 31 is continuously non-rotatably connected to the rotor 32 of the motor 30. Furthermore, two switching elements K and B are assigned to planetary gear 31, wherein switching element K, when operated, ensures the non-rotatable connection between the first element 34 of planetary gear 31 and the rotor 32, and therefore also with the third element 36 of planetary gear 31, which correspondingly results in the interlocking of planetary gear 31. Conversely, switching element B, in the closed state, causes the first element 34 of planetary gear 31 to be fixed on the transmission housing 8, thus preventing subsequent rotational movement of the first element 34.

[0063] In this case, switching elements B and K are respectively implemented as force-locking switching elements, and these two switching elements B and K exist here specifically as plate-type switching elements. Switching element B is constructed as a brake, while switching element K is a clutch.

[0064] The motor 30 and the planetary group 31 are coaxially arranged with each other and also with the drive shaft 9 and the two input shafts 10 and 11. Here, the planetary group 31, together with the switching element K, is arranged axially at the height of the motor 30 and radially inside the motor.

[0065] In addition, a braking device 41 is provided, which is constructed as a friction brake and is permanently coupled to the drive shaft 9. This coupling is achieved here through a transmission stage 42, which exists as a traction transmission mechanism in the form of a chain drive mechanism and has sprockets 43 and 44. Sprocket 43 is non-rotatably connected to the braking device 41, while sprocket 44 is non-rotatably mounted on the drive shaft 9.

[0066] Following the connection between the drive shaft 9 and the torsional damper 3 along the axial direction, first are the spur gear stage 15 and the transmission stage 42, which are substantially in the same plane. Then, along the axial direction, spur gear stage 18, spur gear stage 20, spur gear stage 19, and finally the motor 30 and planetary gear stage 31 are arranged. A switching device 27 is axially positioned between spur gear stages 18 and 20 and coaxially with the countershaft 12. Furthermore, switching devices 28 and 29 are axially positioned between spur gear stages 20 and 19, respectively. Switching device 28 is coaxially with the countershaft 12, and switching device 29 is coaxially with the drive shaft 9 and the input shafts 10 and 11. Finally, a switching element B is axially positioned on the side of the motor 30 opposite to the torsional damper 3.

[0067] Figure 3 Show Figure 1 A partial schematic diagram of a motor vehicle transmission system 1, which in this case has a transmission 4' corresponding to the second design possibility of the present invention. Based on this... Figure 3The design possibilities are basically corresponding to the Figure 2 The only difference in this variant is that the braking device 41 is no longer offset from the axis of the drive shaft 9, but is coaxial with the drive shaft 9 and directly and non-rotatably connected to it. In this variant, the braking device 41 is axially positioned in the region between the motor 30 and the planetary gear 31, and is connected to the drive shaft 9 at the end opposite to the connection point with the torsional damper 3. Furthermore, according to... Figure 3 The implementation method corresponds in other respects to that based on Figure 2 For variations of this scheme, please refer to the relevant notes.

[0068] Depend on Figure 4 Show Figure 1 A partial schematic diagram of a motor vehicle transmission system 1, which has a transmission 4'' constructed according to a third embodiment of the present invention. This embodiment largely corresponds to the one according to... Figure 2 The variant differs in that the switching elements B and K are now axially positioned on one side of planetary gear 31 facing the connection between the drive shaft 9 and the torsional damper 3. Thus, both switching elements B and K can also be reached axially from this side, while the motor 30 is located at the axial end of the gearbox 4''. In other respects, according to... Figure 4 The implementation method is corresponding to that based on Figure 2 For variations of this scheme, please refer to the relevant notes.

[0069] also, Figure 5 Show Figure 1 A partial schematic diagram of a motor vehicle transmission system 1, which in this case has a transmission 4''' corresponding to the fourth design possibility of the present invention. This design possibility also substantially corresponds to the one according to the present invention. Figure 2 A variant of the scheme differs in that, when the switching element K is operated, it now connects the second element 35 of planetary group 31 to the rotor 32 of motor 30 in a non-rotational manner, and therefore also to the third element 36 of planetary group 31. This correspondingly causes interlocking of planetary group 31. In other respects, according to Figure 5 The design possibilities correspond to the Figure 2 For variations of this scheme, please refer to the relevant notes.

[0070] also, Figure 6 Show Figure 1 A partial schematic diagram of a motor vehicle transmission system 1, in which a transmission 4 according to a fifth embodiment of the present invention is disposed. IV In this embodiment, the implementation largely corresponds to the one based on Figure 2 The variant scheme, and based on Figure 2The implementation differs; in the closed state, the switching element K now connects the first element 34 and the second element 35 of planetary group 31 to each other in a non-rotatable manner. This again results in the interlocking of planetary group 31. In other aspects, according to Figure 6 The implementation method is corresponding to that based on Figure 2 For variations of this scheme, please refer to the relevant notes.

[0071] Figure 7 Show Figure 1 A partial schematic diagram of a motor vehicle transmission system 1, which has a transmission 4 constructed according to the sixth design possibility of the present invention. V Transmission 4 V This basically corresponds to Figure 2 The transmission 4 differs in that the switching element B is now implemented as a form-locking switching element. Here, the switching element B is preferably an asynchronous pawl brake, which, in the operated state, secures the first element 34 of planetary 31 to the transmission housing 8. In other respects, according to... Figure 7 The design possibilities correspond to the Figure 2 For variations of this scheme, please refer to the relevant notes.

[0072] also, Figure 8 Show Figure 1 A partial schematic diagram of a motor vehicle transmission system 1, which includes a transmission 4 according to a seventh embodiment of the present invention. VI This implementation largely corresponds to the foregoing. Figure 7 In a variant, the switching elements B and K are now axially positioned on the side of planetary gear 31 facing the connection between the drive shaft 9 and the torsional damper 3. This allows axial access to the switching elements B and K from this side. Conversely, the motor 30 is now located in the gearbox 4. VI On the axial end. In other respects, according to Figure 8 The implementation method is corresponding to that based on Figure 7 For variations of this scheme, please refer to the relevant notes.

[0073] Figure 9 Show Figure 1 A partial schematic diagram of a motor vehicle transmission system 1, which in this case has a transmission 4 according to the eighth design possibility of the present invention. VII The design possibilities also largely correspond to those based on... Figure 7 A variant differs in that, when the switching element K is operated, it now connects the second element 35 of planetary group 31 to the rotor 32 of motor 30 in a non-rotational manner, and therefore also to the third element 36 of planetary group 31. This causes interlocking of planetary group 31. In other respects, according to Figure 9The design possibilities correspond to the Figure 7 For variations of this scheme, please refer to the relevant notes.

[0074] at last, Figure 10 Show Figure 1 A partial schematic diagram of a motor vehicle transmission system 1, which includes a transmission 4 according to a ninth embodiment of the present invention. VIII This implementation method also largely corresponds to... Figure 7 A variant of the scheme differs in that, in the closed state, the switching element K now connects the first element 34 and the second element 35 of planetary group 31 to each other in a non-rotatable manner. This, in turn, results in the interlocking of planetary group 31. In other respects, according to... Figure 10 The implementation method is corresponding to that based on Figure 7 For variations of this scheme, please refer to the relevant notes.

[0075] exist Figure 11 The table shows the information used for Figures 2 to 10 The transmission 4 to 4 VIII An exemplary shift diagram is provided. As shown, four different gears G1 to G4.2 can be engaged. In the columns of the shift diagram, X indicates which of the switching elements S1 to S4 is closed.

[0076] like Figure 11 As can be seen, gear G1 is engaged by closing the switching element S1, which functions between the first input shaft 10 and the output side 14. In gear G1, force is transmitted from the first input shaft 10 via the spur gear stage 18 to the countershaft 12, and then from the countershaft via the spur gear stage to the output side 14. Furthermore, gear G2 can be achieved between the first input shaft 10 and the output side 14 by closing the switching element S2, whereby force is transmitted from the first input shaft 10 via the spur gear stage 20 to the countershaft 12. Then, from the countershaft 12, it is further transmitted to the output side 14 via the spur gear stage 15.

[0077] Gear G3 can be engaged between the second input shaft 11 and the output side 14 via operating switching elements S1 and S3. Thus, power flow originates from the second input shaft 11, is transmitted via spur gear stages 19 and 20 to the first input shaft 10, and then from the first input shaft, is coupled to the countershaft 12 via spur gear stage 18. The countershaft 12 is then coupled to the output side 14 via spur gear stage 15. Therefore, gear G3 is implemented as a detour gear, in which power flow transmission occurs through the coupling of the two sub-transmissions caused by the coupling of the two input shafts 10 and 11.

[0078] Furthermore, in the first variation G4.1, a gear position operating between the second input shaft 11 and the output side 14 can be achieved by operating the switching element S4, which causes the second input shaft 11 and the countershaft 12 to be coupled via the spur gear stage 19. Similar to the previous gear position, further force flow to the output side 14 is transmitted via the spur gear stage 15. Alternatively, this gear position can also be achieved in the second variation G4.2 by operating the switching elements S2 and S3, whereby the coupling between the second input shaft 11 and the output side 14 is also via the spur gear stage 19. However, in this case, the movable gear 25 of the spur gear stage 19 is indirectly fixed to the countershaft 12 via the movable gear 24 of the spur gear stage 20.

[0079] Figures 2 to 10 The transmission 4 to 4 VIII Different operating modes I to XV can be implemented in the vehicle's transmission system 1. Figure 12 The diagram is presented in tabular form. In operating mode I, charging or starting functions can be achieved by closing the switching clutch K2 and operating the switching element K. This is because, in the closed state of the switching clutch K2, the second input shaft 11 is non-rotatably connected to the drive shaft 9 and is therefore also coupled to the internal combustion engine 2 via the intermediate torsional damper 3. The second input shaft 11 is also non-rotatably connected to the rotor 32 of the motor 30 via a planetary segment 31 interlocked by the operation of the switching element K. However, there is no force lock with the output side 14 at this time. In generator-type operation of the motor 32, the electrical energy storage device (not shown further here) can be charged when the motor 30 is driven by the internal combustion engine 2. In motor-electric operation of the motor 30, the internal combustion engine 2 can be started via the motor 30.

[0080] Charging or starting functions can also be achieved in operating mode II. Unlike operating mode I, in this mode, in addition to switching clutch K2, switching element B should also be operated. Therefore, the second input shaft 11 is not non-rotatably connected to the rotor 32 of the motor 30, but is coupled to the rotor 32 through the planetary gear ratio via the switching element B. Thus, by appropriately selecting the fixed transmission ratio of the planetary gear 31, a higher rotor 32 speed than that of the second input shaft 11 can be advantageously achieved.

[0081] Similarly, charging or starting functions can be achieved in operating mode III, in which case the switching clutch K1 and switching elements S3 and K should be closed. Therefore, the second input shaft 11 is coupled to the first input shaft 10 via spur gear stages 20 and 19 based on the operation of switching element S3. This first input shaft is non-rotatably connected to the drive shaft 9 via the switching clutch K1. Furthermore, by simultaneously closing switching element K, the second input shaft 11 is non-rotatably connected to the rotor 32 of the motor 30 via interlocked planetary gear stage 31. Thus, the motor 30 is also coupled to the internal combustion engine 2, thereby enabling charging in generator-type operation of the motor 30 and starting of the internal combustion engine 2 in electric motor-type operation of the motor 32, similar to operating modes I and II.

[0082] The difference between operating mode IV and operating mode III is that switching element B is operated instead of switching element K. Therefore, the rotor 32 of motor 30 is not non-rotatably connected to the second input shaft 11, but is coupled to the second input shaft 11 via planetary gear 31 based on the first element 34, which is fixed in this case. By appropriately selecting the fixed transmission ratio of planetary gear 31, a higher rotor speed than that of the second input shaft 11 and therefore also compared to the drive shaft 9 can be achieved.

[0083] In operating modes V to IX, pure driving via the internal combustion engine 2 can be achieved by respectively activating (as per the information provided). Figure 10 The gears G1 through G4.2 are described, and the corresponding input shaft 10 or 11 is connected to the drive shaft 9 in a non-rotatable manner by closing the corresponding switching clutch K1 or K2. Therefore, gear G3 is engaged in operating mode V, gear G1 in operating mode VI, gear G4.1 in operating mode VII, gear G4.2 in operating mode VIII, and gear G2 in operating mode IX.

[0084] During gear shifting, switching element B or switching element K can be operated separately to support traction via motor 30 during the corresponding gear shift. Synchronization of the participating switching elements is achieved through speed regulation on the internal combustion engine, assisted by braking device 41. The latter can brake the internal combustion engine to a lower speed level during upshifting, and operate the braking device just before reaching the corresponding synchronization speed during downshifting, thus achieving a smaller speed gradient before operating the corresponding switching element. The internal combustion engine 2 must then be automatically accelerated to a higher speed level.

[0085] Conversely, in operating modes X to XV, pure electric driving is achieved via motor 30, which operates as an electric motor and engages one of gears G3, G4.1, or G4.2 respectively. The number of gear ratios available to motor 30 can be correspondingly doubled by operating switching element K on one side and switching element B on the other side in a single gear G3, G4.1, or G4.2. When both switching elements B and K are force-locking switching elements, switching between the gear ratios of a single gear G3, G4.1, or G4.2 can be performed under load. Conversely, if switching element B is implemented as a form-locking switching element (as in...), Figures 7 to 10 In the case of the variant scheme, only traction upshifts and traction downshifts between the gear ratios of a single gear G3, G4.1, or G4.2 can be used as load shifts.

[0086] according to Figures 2 to 10 The modified scheme can, in principle, be changed as follows: the drive shaft 9 extends axially only to the region where the switching clutches K1 and K2 are located, and the second input shaft 11 is implemented as a solid shaft located at its end. This saves the hollow shaft plane in the planetary region 31, reducing manufacturing costs. However, it is advantageous in principle, as according to... Figures 2 to 10 As achieved in the variant, drive shaft 9 extends axially along the entire axial structural length of the transmission and is supported there.

[0087] By means of embodiments of the invention, a compact transmission with low manufacturing cost and a motor connected in a suitable manner can be realized.

[0088] List of reference numerals

[0089] 1. Motor vehicle transmission system

[0090] 2 Internal Combustion Engines

[0091] 3 Torsional vibration dampers

[0092] 4-speed transmission

[0093] 4' transmission

[0094] 4'' transmission

[0095] 4''' transmission

[0096] 4 IV transmission

[0097] 4 V transmission

[0098] 4 VI transmission

[0099] 4 VIItransmission

[0100] 4 VIII transmission

[0101] 5 differentials

[0102] 6 drive wheels

[0103] 7 drive wheels

[0104] 8. Transmission housing

[0105] 9 drive shafts

[0106] 9' drive shaft

[0107] 10 First Input Axis

[0108] 11 Second Input Axis

[0109] 12 sub-shafts

[0110] 13 output shafts

[0111] 14 Output Side

[0112] 15 spur gear stage

[0113] 16 spur gears

[0114] 17 spur gears

[0115] 18 spur gear stage

[0116] 19 spur gear stage

[0117] 20 spur gear stage

[0118] 21 Fixed Gear

[0119] 22 Movable Gear

[0120] 23 Fixed Gear

[0121] 24 Movable Gears

[0122] 25 movable gears

[0123] 26 fixed gears

[0124] 27 Switching device

[0125] 28 Switching Device

[0126] 29 Switching device

[0127] 30 motors

[0128] 31 star levels

[0129] 32 rotors

[0130] 33 stator

[0131] 34 First Component

[0132] 35 Second Component

[0133] 36 Third Component

[0134] 37 Sun Wheel

[0135] 38 planetary frames

[0136] 39 gear ring

[0137] 40 planetary gears

[0138] 41 Braking device

[0139] 42 transmission stages

[0140] 43 sprocket

[0141] 44 sprocket

[0142] S1 switching element

[0143] S2 switching element

[0144] S3 switching element

[0145] S4 switching element

[0146] B switching element

[0147] K switching element

[0148] K1 clutch switching

[0149] K2 clutch switching

[0150] G1 to G4.2 gears

[0151] I to XV operating mode

Claims

1. A transmission for a motor vehicle, the transmission comprising a motor (30), a first input shaft (10), a second input shaft (11), and a countershaft (12), the countershaft (12) being permanently connected to an output side (14), and having a first spur gear stage (20) having a fixed gear (23) disposed on the first input shaft (10) and a movable gear meshing with the fixed gear, the movable gear being rotatably supported on the countershaft (12) and being fixed on the countershaft (12) by a first switching element (S2). It also includes a second spur gear stage (19), which has a fixed gear (26) mounted on a second input shaft (11) and a movable gear meshing with the fixed gear. The movable gear of the second spur gear stage is rotatably supported on a countershaft (12) and can be fixed on the countershaft (12) by a second switching element (S4). The movable gear of the first spur gear stage (20) and the movable gear of the second spur gear stage (19) can be non-rotatably connected to each other by a third switching element (S3). A planetary series (33) is provided, comprising a first element (34), a second element (35), and a third element (36) in the form of a sun gear (37), a planet carrier (38), and a ring gear (39). The second element (35) is non-rotatably connected to the second input shaft (11), and the third element (36) is coupled to the rotor (32) of the motor (30). The first element (34) of the planetary series (31) can be fixed by operating the fourth switching element (B), and two elements (34, 35, 36) of the planetary series (31) can be non-rotatably connected to each other by closing the fifth switching element (K). The planetary series (31) and the fifth switching element (K) move together along... The first input shaft (10) and the second input shaft (11) are axially positioned at the height of the motor (30) and radially positioned inside the motor. The first input shaft (10) and the second input shaft (11) are coaxially positioned with the drive shaft (9). The drive shaft is configured to connect the transmission to the drive mechanism of the motor vehicle. The drive shaft (9) can be non-rotatably connected to the first input shaft (10) via a first switching clutch (K1) and non-rotatably connected to the second input shaft (11) via a second switching clutch (K2). The first input shaft (10) and the second input shaft (11) exist as hollow shafts. The first input shaft and the second input shaft overlap a section of the drive shaft (9) axially and are respectively arranged radially around the drive shaft.

2. The transmission according to claim 1, characterized in that, It is also provided with a third spur gear stage (18) having a fixed gear (21) and a movable gear (22) and a sixth switching element (S1), which, when operated, fixes the movable gear (22) of the third spur gear stage (18) and thereby couples the first input shaft (10) and the secondary shaft (12) together.

3. The transmission according to claim 2, characterized in that, - By closing the sixth switching element (S1), a first gear (G1) is formed between the first input shaft (10) and the output side (14) under the force flow transmission via the third spur gear stage (18). - By operating the first switching element (S2), a second gear (G2) is formed between the first input shaft (10) and the output side (14) under the force flow transmission via the first spur gear stage (20). - By closing the third switching element (S3) and the sixth switching element (S1), a third gear (G3) is formed between the second input shaft (11) and the output side (14) under the force flow transmission via the second spur gear stage (19), the first spur gear stage (20) and the third spur gear stage (18), and a third gear position (G3) is formed. - In the first variant (G4.1), the fourth gear is formed between the second input shaft (11) and the output side (14) by operating the second switching element (S4) and by closing the first switching element (S2) and the third switching element (S3) respectively under the force flow transmission via the second spur gear stage (19).

4. The transmission according to any one of claims 1 to 3, characterized in that, It is also equipped with a braking device (41) which is coupled to the drive shaft (9).

5. The transmission according to claim 4, characterized in that, The braking device (41) is offset from the axis of the drive shaft (9) and is coupled to the drive shaft via a transmission stage (42).

6. The transmission according to claim 4, characterized in that, The braking device (41) is coaxially arranged with the drive shaft (9) and is non-rotatably connected to the drive shaft.

7. The transmission according to any one of claims 1 to 3, characterized in that, The motor (30) is coaxially arranged with the second input shaft (11), and the rotor (32) is connected to the third element (36) of the planetary level (31) in a non-rotatable manner.

8. The transmission according to any one of claims 1 to 3, characterized in that, Each switching element is implemented as a form-locked switching element.

9. The transmission according to any one of claims 1 to 3, characterized in that, The secondary shaft (12) is coupled to the output side (14) via a spur gear stage (15).

10. A motor vehicle transmission system (1), characterized in that, The motor vehicle drivetrain includes a transmission according to any one of claims 1 to 9.

11. The motor vehicle transmission system (1) according to claim 10, characterized in that, The motor vehicle transmission system is a motor vehicle transmission system used in hybrid vehicles or electric vehicles.

12. A method for operating a transmission according to any one of claims 1 to 9, characterized in that, To enable charging operation or starting operation, close the second switching clutch (K2) and operate the fourth switching element (B) or the fifth switching element (K).

13. A method for operating a transmission according to any one of claims 1 to 9, characterized in that, To enable charging operation or starting operation, close the first switching clutch (K1) and operate the third switching element (S3) and the fourth switching element (B) or operate the third switching element (S3) and the fifth switching element (K).

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