Motor vehicle transmission for an at least partially electrically powered motor vehicle

Abstract

The invention relates to a motor vehicle transmission (3) comprising a drive shaft (6), an output shaft (7), a stepped planetary gear set (P1), and a planetary gear set (P2). Furthermore, a first shifting element (A) and a second shifting element (B) are provided, at least functionally, in the motor vehicle transmission (3).

Description

The invention relates to a motor vehicle transmission for an at least partially electrically driven motor vehicle, comprising a drive shaft which is provided for a drive-effective connection to at least one drive machine, preferably at least one electric machine, an output shaft and a stepped planetary gearset which has a first element, a second element, a third element and a fourth element in the form of a sun gear, a planet carrier, a ring gear and a further sun gear or a further ring gear, wherein the planet carrier of the stepped planetary gearset rotatably supports at least one stepped planetary gearset which is in toothed engagement with the sun gear, the ring gear and the further sun gear or the further ring gear, wherein the fourth element of the stepped planetary gearset is connected to the drive shaft in a rotationally fixed manner, whereas the first element of the stepped planetary gearset is connected to the output shaft in a rotationally fixed manner, and wherein at least functionally a first switching element and a second switching element are provided. The invention furthermore relates to a drive unit for an at least partially electrically driven motor vehicle, an electrically driven motor vehicle drive axle for an at least partially electrically driven motor vehicle, a hybrid or electric vehicle and a method for operating a motor vehicle transmission.In motor vehicles designed as electric and hybrid vehicles, a motor vehicle transmission is partially provided in a respective drive train between at least one electric machine and drive wheels of the respective motor vehicle in order to be able to translate a drive movement of the at least one electric machine, in particular into deceleration with respect to the drive wheels. In addition to single-speed transmissions, motor vehicle transmissions are also used in some cases, in which two or more gears can be shifted.DE 11 2011 104 355 T5 discloses a drive train of an electric vehicle. In this drive train, an electric machine is connected in a rotationally fixed manner to a drive shaft of a downstream motor vehicle transmission which, in addition to a differential gearset, has a stepped planetary gearset. The stepped planetary gearset has a planetary carrier which rotatably supports at least one stepped planetary gear, the at least one stepped planetary gear meshing at a first toothing with a sun gear and a first ring gear and meshing at a second toothing with a second ring gear. While the sun gear is connected to the drive shaft in a rotationally fixed manner, the planet carrier is connected to an output shaft in a rotationally fixed manner, which is also connected to an input element of the differential gearset in a rotationally fixed manner. In this case, a coupling of the output shaft with two output shafts is produced via the differential gearset. Furthermore, a switching device is provided, by means of which the function of two switching elements is depicted, wherein the switching device fixes the first ring gear in a first switching state and fixes the second ring gear to a transmission housing in a second switching state.From the disclosed document DE 10 2021 208 564 B3, a transmission for a drive train of an at least partially electrically driven vehicle is known, comprising a stepped planetary gearset, a first gear shift element and a second gear shift element, wherein the stepped planetary gearset has a first sun gear, a first ring gear, a second ring gear and a plurality of stepped planetary gears rotatably mounted on a first planetary carrier. The first sun gear is configured to be operatively connected to an electric machine for driving purposes, wherein the first planet carrier is connected to a housing in a rotationally fixed manner, wherein the gear shift elements are configured to connect the first ring gear or the second ring gear to an output shaft of the transmission in a rotationally fixed manner in a closed state, and wherein one of the two gear shift elements is present in the closed state for the purpose of rotationally driving the output shaft. From document DE 10 2018 101 269 A1 a drive device for a motor vehicle is known, comprising an electric machine, which is operatively connected to a transmission device via a drive shaft, wherein the transmission device has at least one stepped planetary gear set, at least one planetary gear set and a differential gear set. In this case, the stepped planetary set has a plurality of stepped planetary gears, and the stepped planetary gears are rotatably arranged on a first planetary carrier. The first gear is in mesh with a first ring gear, the first ring gear being fixed stationary to a housing. The second gear is in mesh with at least a first sun gear. The input shaft is connected in a rotationally fixed manner to the first and second sun gears, and the second ring gear is connected or connectable to at least one output shaft of the stepped planetary gear set.Proceeding from the prior art described above, it is now the object of the present invention to provide a motor vehicle transmission which is suitable for the incorporation of a drive engine and here preferably an electric machine and by means of which high transmission ratios can be represented in this incorporation.This object is achieved on the basis of the preamble of claim 1 in conjunction with its characterizing features. The dependent claims which follow this represent advantageous further developments of the invention. A drive unit in which a motor vehicle transmission according to the invention is provided is furthermore the subject matter of claim 13 or 14. In addition, claim 15 relates to an electrically drivable motor vehicle drive axle for an at least partially electrically driven motor vehicle, while claim 16 relates to a hybrid or electric vehicle. Finally, claim 17 also relates to a method for operating a motor vehicle transmission according to the invention.According to the invention, a motor vehicle transmission comprises an input shaft, which is provided for a drive-effective connection to at least one drive machine, preferably at least one electric machine, an output shaft and a stepped planetary gearset, which has a first element, a second element, a third element and a fourth element in the form of a sun gear, a planetary carrier, a ring gear and a further ring gear. The planet carrier of the stepped planetary gearset rotatably supports at least one stepped planet gear which meshes with the sun gear, the ring gear and the further ring gear. In addition, the fourth element of the stepped planetary gearset is connected to the drive shaft in a rotationally fixed manner, whereas the first element of the stepped planetary gearset is connected to the output shaft in a rotationally fixed manner. In addition, a first switching element and a second switching element are provided at least functionally.A respective "shaft", such as the drive shaft and the output shaft of the motor vehicle transmission according to the invention, is to be understood in the sense of the invention as a rotatable component of the motor vehicle transmission, via which a power flow guidance between components can be carried out. The respective shaft can connect these components to one another axially or radially or also both axially and radially when guiding the force flow. Thus, the respective shaft can also be present as an intermediate piece, by means of which, for example, a purely radial connection is realized. Furthermore, depending on the profile and connection to the components, the respective shaft can be designed as a solid shaft, as a hollow shaft or partly as a solid shaft and partly as a hollow shaft. Alternatively or additionally, the respective shaft can be embodied in one or more parts.The motor vehicle transmission according to the invention has a drive shaft which, in the motor vehicle transmission according to the invention, is provided for the purpose of producing a drive-side coupling to at least one drive machine, wherein the drive shaft in this case preferably serves for the coupling to exactly one drive machine. For this purpose, the drive shaft is equipped, in particular, with a connection point at which a coupling of the drive shaft to the at least one drive machine can be formed. The connection of the at least one drive machine to the connection point of the drive shaft is carried out in particular permanently in the installed state of the motor vehicle transmission, preferably when the drive machine is designed as an electric machine. Alternatively, however, an intermediate starting element, such as a hydrodynamic torque converter, a starting clutch, etc., can also be provided, via which the drive shaft can be or is coupled at its connection point to the upstream drive machine. This is realized in particular when the drive engine is designed as an internal combustion engine.The coupling between the at least one drive machine and the drive shaft is preferably provided in such a way that in the installed state of the motor vehicle transmission and when the coupling is established between a rotational speed of the drive shaft of the motor vehicle transmission and a rotational speed of the drive machine, a fixed rotational speed ratio prevails at all times. Thus, within the scope of the invention, at least one further transmission stage, such as a spur gear stage and / or a planetary stage, can optionally be provided between the drive shaft and the drive machine, by means of which transmission stage a pretransmission of a rotational movement of the drive machine to the drive shaft can be provided. Preferably, however, the drive shaft serves for a rotationally fixed connection to the at least one drive machine.The motor vehicle transmission is in particular a hybrid or electric vehicle transmission which is provided to be connected at the drive shaft to a drive machine in the form of an electric machine. A rotor of the electric machine can be coupled to the drive shaft of the transmission via at least one intermediate transmission stage, as described above. Particularly preferably, however, a rotor of the electric machine is connected to the drive shaft in a rotationally fixed manner in the installed state of the motor vehicle transmission according to the invention.In the motor vehicle transmission according to the invention, the output shaft is provided in particular for the purpose of producing a coupling of the motor vehicle transmission on the output side to components which, in the installed state of the motor vehicle transmission, follow the motor vehicle transmission in the force flow direction to drive wheels of the respective motor vehicle. Accordingly, the motor vehicle transmission according to the invention is in particular a drive transmission, by means of which a coupling of the at least one drive machine connected to the drive shaft to drive wheels of the respective motor vehicle can be produced in order to translate a drive movement generated via the drive machine with different transmission ratios in each case to the drive wheels.The stepped planetary gearset of the motor vehicle transmission according to the invention is composed of a sun gear, a ring gear, a further sun gear or a further ring gear and a planet carrier, wherein at least one stepped planetary gear is rotatably mounted in the planet carrier. In the stepped planetary gearset, therefore, four elements are present, namely a sun gear, a ring gear, a planetary carrier as well as a further sun gear or a further ring gear. The at least one stepped planetary gear meshes here in each case with the sun gear, with the ring gear and also with the further sun gear or the further ring gear. For this purpose, the at least one stepped planetary gear is equipped in particular with two different axially adjacent tooth arrangements, wherein the tooth engagement with the one sun gear and the one ring gear is carried out on the one tooth arrangement, while the tooth engagement with the other sun gear or the other ring gear takes place on the other tooth arrangement. The tooth arrangements are preferably designed on different diameters of the stepped planetary gear with different numbers of teeth.Within the scope of the invention, these different gear sets can be provided on a stepped planetary gear configured in one piece, wherein the at least one stepped planetary gear is, however, preferably composed of two coaxial spur gears connected to one another in a rotationally fixed manner, of which one spur gear is provided on an outer circumference with the one gear set and meshes with the one sun gear and the one ring gear, while the other spur gear has the other gear set on an outer circumference and meshes with the other sun gear or the other ring gear.The invention now comprises the technical teaching that a planetary gear set is additionally provided, which has a first element, a second element and a third element in the form of a sun wheel, a ring gear and a planetary carrier. In this case, the second element of the planetary gear set is fixed, whereas the third element of the planetary gear set is connected to the output shaft in a rotationally fixed manner. Furthermore, the at least functionally provided first shift element, in an actuated state, connects the second element of the stepped planetary gearset in a rotationally fixed manner to the first element of the planetary gearset, whereas the at least functionally provided second shift element, in an actuated state, connects the third element of the stepped planetary gearset in a rotationally fixed manner to the first element of the planetary gearset.In the motor vehicle transmission according to the invention, the fourth element of the stepped planetary gearset is therefore permanently connected to the drive shaft in a rotationally fixed manner, so that the drive shaft and the fourth element of the stepped planetary gearset always rotate together. Furthermore, there is a rotationally fixed connection between the first element of the stepped planetary gearset and the output shaft, as a result of which the output shaft and the first element of the stepped planetary gearset also rotate permanently together. The output shaft is also continuously connected in a rotationally fixed manner to the third element of the planetary gear set, so that the first element of the stepped planetary gear set and the third element of the planetary gear set are also permanently connected in a rotationally fixed manner to one another. In addition, the second element of the planetary gear set is permanently fixed and thus permanently prevented from rotating.The motor vehicle transmission according to the invention has at least functionally a first shifting element and a second shifting element. An actuated state of the at least functionally provided, first shift element results in a rotationally fixed connection of the second element of the stepped planetary gearset and the first element of the planetary gearset, so that the second element of the stepped planetary gearset and the first element of the planetary gearset then rotate together. The first element of the planetary gear set can also be connected in a rotationally fixed manner to the third element of the stepped planetary gear set by bringing about the actuated state of the at least functionally provided, second shift element. As a result, the third element of the stepped planetary gear set and the first element of the planetary gear set then rotate together.Such a configuration of a motor vehicle transmission has the advantage that high transmission ratios can be realized by the engagements of the stepped planetary gear set and the planetary gear set and by selective actuation of the at least functionally provided shift elements, which ratios are each suitable in particular for the engagement of a drive machine in the form of an electric machine. Thus, by the rotationally fixed connections of the elements of the stepped planetary gearset and of the planetary gearset, when an actuated state of one of the at least functionally provided shift elements is represented, power branching is realized via the stepped planetary gearset and the planetary gearset when power flow is guided from the input shaft to the output shaft. This can also be realized in a compact installation space, so that overall a motor vehicle transmission of compact construction with high transmission ratios is realized.In this case, a first gear can be shifted between the drive shaft and the output shaft by representing an actuated state of the first shift element. In addition, a second gear is represented between the input shaft and the output shaft by realizing an actuated state of the second shift element.In the motor vehicle transmission according to the invention, the drive shaft and the output shaft are arranged in particular coaxially with respect to one another, wherein, further preferably, the stepped planetary gearset and the planetary gearset are also respectively placed coaxially with respect to the drive shaft and the output shaft. This allows a particularly compact construction of the motor vehicle transmission in the radial direction to be realized.In the context of the invention, "axially" means an orientation in the direction of a longitudinal central axis of the motor vehicle transmission, parallel to which axes of rotation of shafts of the motor vehicle transmission and of the elements of the stepped planetary gearset and of the planetary gearset are also oriented. The term "radial" is then to be understood as meaning an orientation in the diameter direction of a respective component of the transmission, in particular of a respective shaft or of a respective element of the stepped planetary gear set or of the planetary gear set.Very particularly preferably, in the motor vehicle transmission according to the invention, exactly two shift elements are provided for shifting different gears between the drive shaft and the output shaft at least from the functional point of view, wherein, however, further, at least functionally provided shift elements may optionally also be provided for shifting further gears within the scope of the invention. The fact that a respective shift element is provided "at least functionally" means, within the meaning of the invention, that at least the respective function of the respective shift element is depicted in the motor vehicle transmission according to the invention. In this case, the respective switching element can actually be physically present in detail as an individual switching element or the function of the respective switching element is depicted by another component, such as a switching device, for example. A component which forms the function can then combine the function of two switching elements in one device.A "rotationally fixed" connection of components of the transmission is to be understood in the sense of the invention as meaning that these components which are connected to one another in a rotationally fixed manner or are connected to one another in a rotationally fixed manner are rigidly connected to one another and therefore always have the same rotational speed. In this case, the components connected to one another in a rotationally fixed manner or connected to one another in a rotationally fixed manner can be present as separate components which are fastened to one another. Alternatively, components connected to one another in a rotationally fixed manner or connected to one another in a rotationally fixed manner can also be embodied in one piece and are thus present together as a component, wherein this is realized in particular when these components are arranged lying spatially close to one another.Within the scope of the invention, a fixed state of a component of the motor vehicle transmission is realized in particular by a rotationally fixed connection to a permanently fixed component, which can be a housing of the motor vehicle transmission, a part of the housing or a component permanently connected thereto in a rotationally fixed manner. In the present case, the second element of the planetary gear set is then permanently connected to the stationary component in a rotationally fixed manner, wherein here a one-piece design of the third element of the planetary gear set with the stationary component would also be conceivable.In the sense of the invention, a rotationally fixed connection between components of the motor vehicle transmission via an at least functionally provided shift element means that the components are not permanently coupled to one another, but a rotationally fixed connection is only carried out by illustrating an actuated state of the at least functionally provided, intermediate shift element. In this case, an actuated state of the at least functionally provided switching element in the sense of the invention means that the relevant switching element is transferred into a closed state and as a result the rotational movements of the components directly coupled thereto are equalized. If at least the function of a form-locking shift element is depicted, the components directly connected to one another in a rotationally fixed manner via this will run at the same speed, while in the case of a mapping of at least the function of a force-locking shift element, even after the representation of an actuated state, the same speed difference between the components can exist. This wanted or also unwanted state is nevertheless referred to within the scope of the invention as a rotationally fixed connection of the respective components via the at least functionally provided shifting element.The planetary gear set is composed of a first element, a second element and a third element, wherein of these elements an element is configured as a sun gear, an element as a planetary carrier and an element as a ring gear. The planetary gear set is preferably present here as a minus planetary gear set, in which the planetary carrier guides at least one planetary gear rotatably mounted, wherein the at least one planetary gear is in mesh with both the sun gear of the planetary gear set and the ring gear of the planetary gear set. In particular, a plurality of planetary gears are rotatably mounted in the planetary carrier. Alternatively, the planetary gear set could also be designed as a plus planetary gear set. In this case, at least one pair of planet wheels is rotatably mounted in the planet carrier of the planetary gear set, of which planet wheels a planet wheel meshes with the sun wheel of the planetary gear set and a planet wheel meshes with the ring wheel of the planetary gear set. In addition, the planetary gears of the at least one pair of planetary gears mesh with one another.According to an embodiment of the invention, the first element of the stepped planetary gearset is the planet carrier of the stepped planetary gearset, the second element of the stepped planetary gearset is the ring gear of the stepped planetary gearset, the third element of the stepped planetary gearset is another ring gear of the stepped planetary gearset, and the fourth element of the stepped planetary gearset is the sun gear of the stepped planetary gearset. In this case, the stepped planetary gearset therefore has, in addition to the planetary carrier, exactly one sun wheel and exactly two ring gears. The first element of the stepped planetary gearset is formed by the planetary carrier of the stepped planetary gearset, while the second element of the stepped planetary gearset is formed by one ring gear, the third element of the stepped planetary gearset by the other ring gear, and the fourth element of the stepped planetary gearset by the exactly one sun gear.In a development of this embodiment, the at least one stepped planet gear of the stepped planetary gearset meshes with the sun gear of the stepped planetary gearset and the further ring gear of the stepped planetary gearset on a first toothing each, the at least one stepped planet gear of the stepped planetary gearset also meshing with the ring gear of the stepped planetary gearset on a second toothing each.According to one possible embodiment of the invention, the output shaft is coupled to an input element of a differential gearset, which drive-effectively connects the output shaft to two output shafts. In an advantageous manner, a distribution of a drive torque produced at the output shaft to the two output shafts can thereby be carried out, wherein a rotational speed compensation between the output shafts can also be implemented via the differential gearset. The differential gearset functions in particular as a transverse differential and is preferably designed in the manner of a bevel gear differential. Via the transverse differential thus formed, a distribution of a drive movement transmitted to the output shaft of the motor vehicle transmission is preferably carried out to the output shafts, which are preferably assigned to a motor vehicle drive axle. The differential gearset can, however, also have the function of a longitudinal differential, via which a distribution of a drive power to a plurality of drive axles can be carried out. As an alternative to an embodiment as a bevel gear differential, the differential gearset can also be designed as a planetary gear differential, as a spur gear differential, etc. within the scope of the invention.The input element to which the output shaft is coupled is preferably a differential cage of the differential gearset. When the differential gearset is used as a transverse differential and the motor vehicle transmission is installed transversely to a direction of travel of the associated motor vehicle, the output shaft is then preferably connected to the input element in a rotationally fixed manner. This is also realized in particular when the differential gearset functions as a longitudinal differential and the motor vehicle transmission is oriented in the direction of travel of the motor vehicle. When the motor vehicle transmission is installed in the direction of travel and the differential gearset is used as a transverse differential, in contrast, in particular the output shaft is coupled to the input element via a bevel drive. Such a bevel gear is also preferably used when the differential gearset is provided as a longitudinal differential and the motor vehicle transmission is oriented transversely to the direction of travel.In the motor vehicle transmission according to the invention, the design option according to which the output shaft is coupled to an input element of a differential gearset is particularly preferred combined with the variant protruding above. The differential gearset is then located axially overlapping with and radially inward of the tooth meshing of the at least one stepped planetary gear of the stepped planetary gearset with the ring gear of the stepped planetary gearset. This allows an interleaved arrangement of the differential gearset with the stepped planetary gearset, wherein the differential gearset at least partially overlaps axially with the meshing of the at least one stepped planetary gearset with the ring gear. As a result, the axial structural length of the motor vehicle transmission can be further reduced. Alternatively or additionally, the differential gearset can also be arranged axially overlapping with and radially inside the planetary gearset, whereby a reduction in the axial overall length of the motor vehicle transmission is also possible.According to a variant of the invention, the first element of the planetary gear set is the sun gear of the planetary gear set, whereas the second element of the planetary gear set is the planet carrier of the planetary gear set when the planetary gear set is designed as a minus planetary gear set and the ring gear of the planetary gear set when the planetary gear set is designed as a plus planetary gear set, wherein the third element of the planetary gear set is the ring gear of the planetary gear set when the planetary gear set is designed as a minus planetary gear set and the planet carrier of the planetary gear set when the planetary gear set is designed as a plus planetary gear set.Alternatively, the third member of the planetary gear set is the sun gear of the planetary gear set. In addition, the second element of the planetary gear set is then the planet carrier of the planetary gear set when the planetary gear set is designed as a minus planetary gear set and the ring gear of the planetary gear set when the planetary gear set is designed as a plus planetary gear set, whereas the first element of the planetary gear set is the ring gear of the planetary gear set when the planetary gear set is designed as a minus planetary gear set and the planet carrier of the planetary gear set when the planetary gear set is designed as a plus planetary gear set.According to one embodiment of the invention, the first switching element and the second switching element are formed by a common switching device which has a coupling element. The coupling element can be positioned in a first shift position and in a second shift position, respectively, wherein the coupling element in the first shift position functionally depicts an actuated state of the first shift element and connects the second element of the stepped planetary gear set in a rotationally fixed manner to the first element of the planetary gear set. In the second shift position, the coupling element then functionally depicts an actuated state of the second shift element and brings the third element of the stepped planetary gearset into connection with the first element of the planetary gearset in a rotationally fixed manner. As a result, the function of the first shift element and of the second shift element can be reproduced by a shift device and thus in a compact manner. For the representation of the actuated states, as a result, furthermore only one common actuating actuator system is necessary, by means of which the coupling element can be positioned in the respectively different switching positions. The coupling element can preferably be positioned between the shift positions or in an intermediate neutral position in which neither an actuated state of the first shift element nor an actuated state of the second shift element is represented.The aforementioned shifting device is in particular designed such that the coupling element is guided in a rotationally fixed manner on a first toothing in the two shift positions and in the event of an axial displacement between the two shift positions, said toothing being connected in a rotationally fixed manner to the first element of the planetary gear set. In the first shift position, the coupling element then additionally includes a second toothing which is connected in a rotationally fixed manner to the second element of the stepped planetary gearset, wherein the coupling element includes, in the second shift position, a third toothing which is connected in a rotationally fixed manner to the third element of the stepped planetary gearset.The coupling element of the shifting device is present in particular as a sliding sleeve. The coupling element preferably has one or more clutch tooth arrangements, on which the axial, rotationally fixed guidance takes place on the first tooth arrangement and / or the respective embedding in the second and third tooth arrangements can be carried out. The tooth arrangements are preferably designed as claw tooth arrangements, so that the function of unsynchronized claw shift elements is depicted via the shifting device. Alternatively, however, the first shifting element and the second shifting element could also be present as individual shifting elements, wherein the shifting elements in this case are in particular designed as form-locking shifting elements and in this case particularly preferably as unsynchronized claw shifting elements. As a further alternative, however, individual shift elements could also be designed as locking synchronizations or as force-locking shift elements, in particular in the form of multi-disk shift elements.It is a further embodiment of the invention that a parking lock element is additionally provided, which in an actuated state fixes the output shaft directly or indirectly. In an advantageous manner, a parking lock function can thereby be realized in the motor vehicle transmission according to the invention by actuating the parking lock element. In this case, the output shaft is fixed when the parking lock function is activated, as a result of which rolling away of a motor vehicle having the motor vehicle transmission according to the invention can be reliably prevented.Within the scope of the invention, the parking lock element can connect the output shaft directly to a permanently fixed component in a rotationally fixed manner when actuated. Particularly preferably, however, the parking lock element is arranged in the power flow between two of the elements of the planetary gear set and, in an actuated state, connects these two elements of the planetary gear set to one another in a rotationally fixed manner. As a result, the parking lock element causes the planetary gear set to become locked when actuated, which also results in the output shaft being locked due to the permanently rotationally fixed connection of the output shaft to the third element of the planetary gear set and the permanently fixed state of the second element of the planetary gear set. It is advantageous here that in this arrangement the parking lock element can be dimensioned smaller, since due to the intermediate connection of the planetary gear set a lower torque is present than in the case of a direct connection to the output shaft. The parking lock element can be arranged in the power flow between the first element and the second element of the planetary gear set, the first element and the third element of the planetary gear set or the second element and the third element of the planetary gear set.The parking lock element is in particular a further shifting element which, however, is not provided for realizing a transmission ratio between the drive shaft and the output shaft, but rather serves for the direct or indirect fixing of the output shaft. The parking lock element is preferably present here as a form-locking shifting element and in this case in particular as a claw shifting element, wherein the parking lock element could, however, just as well be embodied as a force-locking shifting element.The parking lock element is placed in particular axially covering and radially surrounding the differential gearset. This allows an axially compact arrangement. In this case, the parking lock element is preferably located axially between the stepped planetary gearset and the planetary gearset.The invention also relates to a drive unit which, in addition to at least one electric machine, has a motor vehicle transmission according to one or more of the variants described above. In this case, a respective rotor of the at least one electric machine is coupled to the drive shaft of the motor vehicle transmission. In the context of the invention, the at least one electric machine can be operated in particular on the one hand as a generator and on the other hand as an electric motor. As a result, a drive unit can be created which is suitable for use in a motor vehicle in the form of an electric or hybrid vehicle. Particularly preferably, in the drive unit, exactly one electric machine is provided in addition to the motor vehicle transmission.The at least one electric machine is preferably each connected in a rotationally fixed manner to the drive shaft of the motor vehicle transmission, wherein the at least one electric machine is then arranged coaxially with respect to the drive shaft. As a result, the drive shaft and the respective rotor of the at least one electric machine run under the same rotational speed during operation. Alternatively, however, it is also conceivable that the respective rotor of the at least one electric machine is connected in a rotationally fixed manner to a respective intermediate shaft of the motor vehicle transmission, which intermediate shaft is coupled to the drive shaft via at least one transmission stage, so that the at least one electric machine is then optionally offset from the drive shaft. Depending on the design of the at least one transmission stage, however, a coaxial arrangement of the at least one electric machine with respect to the drive shaft is also possible.Preferably, the stepped planetary gear set of the motor vehicle transmission is placed axially between the at least one electric machine and the planetary gear set of the motor vehicle transmission. This allows a suitable construction of a drive unit.A drive unit designed according to one of the aforementioned variants is in particular part of an electrically drivable motor vehicle drive axle, which is provided for an electric or hybrid vehicle. The motor vehicle transmission preferably has a differential gearset which is coupled to the output shaft and couples the output shaft to output shafts. Each of the output shafts is assigned to a drive wheel of the motor vehicle drive axle.An aforementioned motor vehicle drive axle is provided in the context of the invention in the case of a hybrid or electric vehicle, which can be a passenger car or a commercial vehicle. A commercial vehicle can be present here as an at least partially electrically driven transporter or a light to medium-weight bus or truck.Advantageous embodiments of the invention, which are explained below, are illustrated in the drawings. It shows: FIGS. 1 to 6 each show a schematic representation of a drive unit according to one embodiment of the invention; FIG. 7 shows an exemplary shift pattern of a respective motor vehicle transmission of the respective drive unit from FIGS. 1 to 6 ; and FIG. 8 is a schematic view of an electric vehicle according to a preferred embodiment of the invention.FIG. 1 shows a schematic view of a drive unit 1, which is designed according to an embodiment of the invention. This drive unit 1 is composed of an electric machine 2 and a motor vehicle transmission 3, which is designed according to one possible embodiment of the invention. The electric machine 2 is formed in a manner known in principle to the person skilled in the art by a stator 4 and a rotor 5, wherein the electric machine 2 can be operated on the one hand as a generator and on the other hand as an electric motor.The motor vehicle transmission 3 has, in addition to an input shaft 6 and an output shaft 7, a stepped planetary gearset P 1 and a planetary gearset P 2. The stepped planetary gear set P 1 includes a first element E 11, a second element E 21, a third element E 31, and a fourth element E 41. While the first element E 11 of the stepped planetary gearset P 1 is present as a planetary carrier 8, the second element E 21 and the third element E 31 are each a ring gear 9 or 10, respectively.As can be seen in FIG. 1, at least one stepped planetary gear 12 is rotatably mounted in the planetary carrier 8 of the stepped planetary gear set P 1, which planetary gear has two axially adjacent tooth arrangements 13 and 14. While tooth meshings with the sun gear 11 and the ring gear 10 are produced on the toothing 13, the at least one stepped planetary gear 12 meshes with the ring gear 9 on the toothing 14.The planetary gear set P 2 has a first element E 12, a second element E 22 and a third element E 32, of which the first element E 12 of the planetary gear set P 2 is a sun gear 15 of the planetary gear set P 1, the second element E 22 of the planetary gear set P 2 is a planet carrier 16 of the planetary gear set P 2 and the third element E 32 of the planetary gear set P 2 is a ring gear 17 of the planetary gear set P 2. In the planetary carrier 16, at least one planetary gear 18 is rotatably mounted, which is in mesh with both the sun gear 15 and the ring gear 17. In this respect, the planetary gear set P 2 is designed as a minus planetary gear set in the present case.In the present case, the fourth element E 41 of the stepped planetary gearset P 1 is connected in a rotationally fixed manner to the drive shaft 6, which is additionally connected in a rotationally fixed manner to the rotor 5 of the electric machine 2. In this respect, the fourth element E 41 and thus the sun gear 11 of the stepped planetary gearset P 1 and the rotor 5 are also connected to one another in a rotationally fixed manner via the drive shaft 6, as a result of which the fourth element E 41 and the rotor 5 always rotate at the same rotational speed. Within the scope of the invention, the drive shaft 6 can be configured in one piece with the rotor 5 of the electric machine 2 and / or with the sun gear 11 of the stepped planetary gearset P 1 forming the fourth element E 41.The first element E 11 of the stepped planetary gearset P 1 is permanently connected in a rotationally fixed manner to the output shaft 7, which is additionally connected in a rotationally fixed manner to the third element E 32 of the planetary gearset P 2, so that the output shaft 7 runs continuously at the same rotational speed together with the planetary carrier 8 of the stepped planetary gearset P 1 forming the first element E 11 and with the ring gear 17 of the planetary gearset P 2 forming the third element E 32. The output shaft could be configured in one piece with the planetary carrier 8 and / or with the ring gear 17.In addition, the second element E 22 of the planetary gear set P 2 is permanently connected in a rotationally fixed manner to a permanently fixed component 19, which is preferably a transmission housing of the motor vehicle transmission 3, a part of such a transmission housing or a component connected thereto in a rotationally fixed manner. In this respect, the planet carrier 16 of the planetary gear set P 2 forming the second element E 22 is permanently fixed, wherein the second element E 22 could also be formed integrally with the permanently fixed component 19.In addition to the first element E 11 of the stepped planetary gearset P 1 and the third element E 32 of the planetary gearset P 2, the output shaft 7 is also permanently connected in a rotationally fixed manner to an input element 20 in the form of a differential carrier of a differential gearset 21. This differential gearset 21 is designed as a differential bevel gear, which, in a manner known in principle to the skilled person, distributes a drive torque introduced into the input element 20 via the output shaft 7 to two output shafts 22 and 23. In this case, the differential gearset 21 also permits rotational speed differences between the output shafts 22 and 23.The motor vehicle transmission 3 also has a shifting device 24, in which a coupling element 25 in the form of a sliding sleeve is provided. The coupling element 25 is guided in a rotationally fixed and axially displaceable manner on a toothing 26 which is connected in a rotationally fixed manner to the first element E 12 of the planetary gear set P 2. In this case, this rotationally fixed connection of the toothing 26 to the first element E 12 of the planetary gear set P 2 is produced via a shaft 27, which could be embodied in one piece with the sun wheel 15 forming the first element E 12 of the planetary gear set P 2. Axial displacements of the coupling element 25 on the toothing 26 can be carried out via an adjusting actuator-not shown in detail here-which is preferably designed as an electromechanical adjusting actuator.The coupling element 25 can be moved via the actuator between two different switching positions in which the coupling element 25 meshes with respective associated teeth 28 and 29. The toothing 28 is connected in a rotationally fixed manner to the second element E 21 of the stepped planetary gearset P 1, while the toothing 29 is connected in a rotationally fixed manner to the third element E 31 of the stepped planetary gearset P 1.The switching device 24 represents the function of two switching elements A and B, the respective actuated state of which the switching device 24 represents in each case one of its switching states. Thus, an actuated state of the shift element A is realized in a first shift position of the clutch element 25, in which the clutch element 25 engages in the toothing 28 and thus connects the second element E 21 of the stepped planetary gearset P 1 in the form of the ring gear 9 in a rotationally fixed manner to the shaft 27 and thus to the first element E 12 of the planetary gearset P 2. From the first shift position, the coupling element 25 can be moved via the actuator into a neutral position, which is shown in FIG. 1 and in which no coupling is carried out via the coupling element 25. In addition to a transfer of the coupling element 25 into the first switching position, the coupling element 25 can also be moved from the neutral position into a second switching position, in which a tooth engagement of the coupling element 25 into the toothing 29 takes place. As a result, the coupling element 25 connects the third element E 31 of the stepped planetary gearset P 1 to the shaft 27 in a rotationally fixed manner, which accordingly results in a rotationally fixed connection of the third element E 31 to the first element E 12 of the planetary gearset P 2 and corresponds to an actuated state of the shift element B.In the present case, the electric machine 2 is placed coaxially with the motor vehicle transmission 3, in which, in addition, the input shaft 6, the stepped planetary gearset P 1 and the planetary gearset P 2, the output shaft 7, the output shafts 22 and 23, the shaft 27 and the differential gearset 21 are arranged coaxially with one another. In this case, the stepped planetary gearset P 1 is arranged axially between the electric machine 2 and the planetary gearset P 2, the differential gearset 21 being arranged axially overlapping with the stepped planetary gearset P 1. Specifically, the differential gearset 21 is located axially overlapping with and radially inward of the tooth meshing of the stepped planetary gear 12 with the ring gear 9, thereby achieving a nested arrangement of the stepped planetary gearset P 1 and the differential gearset 21. The shifting device 24 is arranged radially surrounding the stepped planetary gearset P 1 and the planetary gearset P 2, wherein the shifting device 24 is placed here axially substantially overlapping with the stepped planetary gearset P 1 and the differential gearset 21.For the rotationally fixed connection to the third element E 32 of the planetary gear set P 2, the output shaft 7 is guided from the side of the planetary gear set P 2 axially facing the stepped planetary gear set P 1 radially on the inside to the planetary gear set P 2 on the axial side opposite thereto, wherein the output shaft 7 then extends radially on the outside for the rotationally fixed connection to the third element E 32 of the planetary gear set P 2. The shaft 27 is likewise led up from the side of the planetary gear set P 2 axially facing the stepped planetary gear set P 1 and radially surrounding the output shaft 7 and radially inside the planetary gear set P 2, wherein the shaft 27 is then guided axially onto the side of the planetary gear set P 2 axially facing away from the stepped planetary gear set P 1 and connected to the first element E 12 of the planetary gear set P 2 in a rotationally fixed manner. The connection of the second element E 22 of the planetary gear set P 2 in a rotationally fixed manner to the permanently fixed component 19 is carried out radially at the level of the planetary gear set P 2 and axially from the side facing the stepped planetary gear set P 1. While the output shafts 22 and 23 are designed as solid shafts, the drive shaft 6, the output shaft 7 and the shaft 27 are present as hollow shafts.Furthermore, FIG. 2 shows a schematic view of a drive unit 30 according to a further possible embodiment of the invention, wherein this possible embodiment corresponds to the greatest possible extent here to the preceding variant according to FIG. 1. In contrast to the drive unit 1 from FIG. 1, a motor vehicle transmission 31 of the drive unit 30 additionally has a parking lock element P, in the actuated state of which the output shaft 7 is indirectly fixed.The parking lock element P is arranged in the power flow between the output shaft 7 and the shaft 27 and, in an actuated state, connects the output shaft 7 and the shaft 27 to one another in a rotationally fixed manner, as a result of which, ultimately, in the planetary gear set P 2, the first element E 12 and the third element E 32 are also connected to one another in a rotationally fixed manner. This results in the planetary gear set P 2 being locked, so that the output shaft 7 is also locked due to the permanently fixed state of the second element E 22 of the planetary gear set P 2.The parking lock element P is designed here as a form-locking shifting element, wherein the parking lock element P is designed here specifically as a claw shifting element. The parking lock element is provided axially between the stepped planetary gearset P 1 and the planetary gearset P 2, wherein the parking lock element P is placed axially overlapping with and radially surrounding the differential gearset 21. Otherwise, the embodiment according to FIG. 2 corresponds to the variant according to FIG. 1, so that reference is made to the description thereof.FIG. 3 shows a schematic view of a drive unit 32 according to a further possible embodiment of the invention, wherein this drive unit 32 corresponds to the greatest possible extent to the preceding variant according to FIG. 2. In contrast to the drive unit 30 according to FIG. 2, in a motor vehicle transmission 33 of the drive unit 32, the parking lock element P is arranged in the force flow between the shaft 27 and the permanently fixed component 19. Accordingly, actuation of the parking lock element P results in the shaft 27 and thus also of the first element E 12 of the planetary gear set P 2 being fixed on the permanently fixed component 19, which results in the planetary gear set P 2 being locked and thus also in a corresponding fixing of the output shaft 7 connected to the third element E 32 of the planetary gear set P 2. Moreover, the design option according to FIG. 3 corresponds to the variant according to FIG. 2, so that reference is made to the one described for this purpose.Furthermore, FIG. 4 shows a schematic illustration of a drive unit 34, which is designed in accordance with a further embodiment of the invention and corresponds substantially to the variant according to FIG. 1. In contrast to the variant according to FIG. 1, the incorporation of the planetary gear set P 2 is carried out differently. Again, the output shaft 7 is guided axially to the planetary gear set P 2 from the side of the planetary gear set P 2 facing the stepped planetary gear set P 1 for the connection in a rotationally fixed manner to the third element E 32 of the planetary gear set P 2, wherein this guiding is realized radially on the outside of the planetary gear set P 2, however. In addition, the shaft 27 runs from the side of the planetary gear set P 2 axially facing the stepped planetary gear set P 1 radially on the outside to the planetary gear set P 2 on the side of the planetary gear set P 2 axially opposite thereto, wherein the shaft 27 is then guided radially on the inside on this side in order to establish the rotationally fixed connection to the first element E 12 of the planetary gear set P 2. Finally, the rotationally fixed connection of the second element E 22 of the planetary gear set P 2 to the permanently fixed component 19 is also produced axially on the side of the planetary gear set P 2 facing the stepped planetary gear set P 1, wherein, starting from the rotationally fixed connection to the second element E 22, firstly a course toward the radially inner side and subsequently an axial course to the side of the planetary gear set P 2 facing away from the stepped planetary gear set P 1 is realized, whereupon then the rotationally fixed connection to the permanently fixed component 19 is realized by a course toward the radially outer side. Otherwise, the embodiment according to FIG. 4 corresponds to the variant according to FIG. 1, so that reference is made to the description thereof.FIG. 5 shows a schematic view of a further drive unit 36 according to the invention, which corresponds here to the greatest extent to the drive unit 1 from FIG. 1. In contrast to the variant according to FIG. 1, however, in the planetary gear set P 2 of a motor vehicle transmission 37 of the drive unit 36, the first element E 12 is now formed by a ring gear 38 which is connected to the shaft 27 in a rotationally fixed manner.A planet carrier 40 guiding at least one planet gear 39 still forms the second element E 22 of the second planetary gear set P 2 and is permanently connected in a rotationally fixed manner to the permanently fixed component 19 in a manner analogous to the variant according to FIG. 1. The third element E 32 of the planetary gear set P 2 is now present as a sun gear 41 which is connected in a rotationally fixed manner to the output shaft 7 and also to the planet carrier 8 of the stepped planetary gear set P 1. The planetary gear set P 2 is still designed as a minus planetary gear set.For the incorporation of the planetary gear set P 2, the shaft 27 is axially extended from the radially outer side of the planetary gear set P 2 facing the stepped planetary gear set P 1 to the planetary gear set P 2, whereas the output shaft 7 likewise extends axially from the side facing the stepped planetary gear set P 1 radially inner to the planetary gear set P 2. The rotationally fixed connection to the permanently fixed component 19, on the other hand, is produced on the side of the planetary gear set P 2 facing away from the stepped planetary gear set P 1. Otherwise, the embodiment according to FIG. 5 corresponds to the variant according to FIG. 1, so that reference is made to the description thereof.Furthermore, FIG. 6 shows a schematic illustration of a drive unit 42 which is designed according to a further embodiment of the invention and corresponds substantially to the drive unit 36 according to FIG. 5. The drive unit 42 differs from the drive unit 36 in that in a motor vehicle transmission 43 of the drive unit 42 the planetary gear set P 2 is now placed axially overlapping with and radially surrounding the differential gear set 21. The rotationally fixed connection of the third element E 32 of the planetary gear set P 2 to the output shaft 7 is produced in that the third element E 32 of the planetary gear set P 2 is connected rotationally fixed to the input element 20 of the differential gear set 21. Otherwise, the embodiment according to FIG. 6 corresponds to the variant according to FIG. 5, so that reference is made to the description thereof.FIG. 7 is a table of an exemplary shift pattern of the motor vehicle transmissions 3, 31, 33, 35, 37 and 43 from FIGS. 1 to 6. As can be seen, a total of two gears G 1 and G 2 can be realized between the input shaft 6 and the output shaft 7, wherein an X is respectively labeled in the columns of the shift pattern, which actuated states of the shift elements A and B formed by the shift device 24 are to be represented in the individual gear. In each of the gears G 1 and G 2, an actuated state is to be represented in each case in one of the shift elements A and B.As can be seen in FIG. 7, a first gear G 1 is shifted between the input shaft 6 and the output shaft 7 by representing the actuated state of the shift element A in the shifting device 24. For shifting a second gear G 2, the actuated state of the shift element B is then to be realized in the shifting device 24. Synchronization of rotational speeds when engaging a respective gear can be at least assisted by a corresponding braking or acceleration of the drive shaft 6 via the electric machine 2, wherein this is carried out in the course of the illustration of the neutral position of the shifting device 24.Finally, FIG. 8 shows a schematic view of an electric vehicle 44, which can be, in particular, an electric utility vehicle, such as a transporter. In addition to a steerable, non-driven vehicle axle 45, the electric vehicle 44 also has a motor vehicle drive axle 46 with drive wheels 47 and 48. The drive wheel 47 is connected in a rotationally fixed manner to the output shaft 22 of the drive unit 49, while the drive wheel 48 is connected in a rotationally fixed manner to the output shaft 23 of the drive unit 49.While the vehicle axle 45 is a front axle of the electric vehicle 44, the motor vehicle drive axle 46 is a rear axle of the electric vehicle 44. however, as an alternative or in addition to the motor vehicle drive axle 46, the vehicle axle 45 could also be designed as a driven axle with an optionally analogous design of a drive unit.By means of the configuration according to the invention, a motor vehicle transmission of compact construction can be realized with suitable transmission ratios for the integration of an electric machine.Reference numerals denote reference numerals1 Drive unit 2 Electric machine 3 Motor vehicle transmission 4 Stator 5 Rotor 6 Drive shaft 7 Output shaft 8 Planet carrier 9 Ring gear 10 Ring gear 11 Sun gear 12 Stepped planet gear 13 Toothing 14 Toothing 15 Sun gear 16 Planet carrier 17 Ring gear 18 Planet gear 19 Fixed component 20 Input element 21 Differential gearset 22 Output shaft 23 Output shaft 24 Switching device 25 Coupling element 26 Toothing 27 Shaft 28 Toothing 29 Toothing 30 Drive unit 31 Motor vehicle transmission 32 Drive unit 33 Motor vehicle transmission 34 Drive unit 35 Motor vehicle transmission 36 Drive unit 37 Motor vehicle transmission 38 Ring gear 39 Planet gear 40 Planet carrier 41 Sun gear 42 Drive unit 43 Motor vehicle transmission 44 Electric vehicle 45 Vehicle axle 46 Motor vehicle drive axle 47 Drive gear 48 Drive gear 49 Drive unit P 1 Stepped planet gearset P 2 Planetary gearset E 11 First element Stepped planet gearset E 21 Second element Stepped planetary gearset E 31 Third element Stepped planetary gearset E 41 Fourth element Stepped planetary gearset E 12 First element Planetary gearset E 22 Second element Planetary gearset E 32 Third element Planetary gearset A Shift element B Shift element P Park lock element G 1 First gear G 2 Second gear

Claims

Motor vehicle transmission (3; 31; 33; 35; 37; 43) for an at least partially electrically driven motor vehicle, comprising a drive shaft (6) which is provided for a drive-effective connection to at least one drive machine, preferably at least one electric machine (2), an output shaft (7) and a stepped planetary gearset (P1) which has a first element (E11), a second element (E21), a third element (E31) and a fourth element (E41) in the form of a sun wheel (11), a planet carrier (8), a ring wheel (9) and a further ring wheel (10), wherein the first element (E11) of the stepped planetary gearset (P1) has the planet carrier (8) of the stepped planetary gearset (P1), the second element (E21) of the stepped planetary gearset (P1) is the ring gear (9) of the stepped planetary gearset (P1), the third element (E31) of the stepped planetary gearset (P1) is a further ring gear (10) of the stepped planetary gearset (P1), and the fourth element (E41) of the stepped planetary gearset (P1) is the sun gear (11) of the stepped planetary gearset (P1), the planet carrier (8) of the stepped planetary gearset (P1) rotatably supporting at least one stepped planetary gear (12) which meshes with the sun gear (11), the ring gear (9) and the further ring gear (10), the fourth element (E41) of the stepped planetary gearset (P1) being connected to the drive shaft (6) in a rotationally fixed manner, whereas the first element (E11) of the stepped planetary gearset (P1) is connected to the output shaft (7) in a rotationally fixed manner, and wherein at least functionally a first shifting element (A) and a second shifting element (B) are provided, characterized in that - a planetary gearset (P2) is also provided, which has a first element (E12), a second element (E22) and a third element (E32) in the form of a sun wheel (15; 41), a ring wheel (17; 38) and a planetary carrier (16; 40), - that the second element (E22) of the planetary gear set (P2) is fixed, - that the third element (E32) of the planetary gear set (P2) is connected in a rotationally fixed manner to the output shaft (7), - and that the at least functionally provided first shift element (A) in an actuated state connects the second element (E21) of the stepped planetary gear set (P1) in a rotationally fixed manner to the first element (E12) of the planetary gear set (P2), whereas the at least functionally provided second shift element (B) in an actuated state connects the third element (E31) of the stepped planetary gear set (P1) in a rotationally fixed manner to the first element (E12) of the planetary gear set (P2).Motor vehicle transmission (3; 31; 33; 35; 37; 43) according to Claim 1, characterized in that the at least one stepped planet wheel (12) of the stepped planetary gearset (P1) meshes on a respective first toothing (13) with the sun wheel (11) of the stepped planetary gearset (P1) and the further ring wheel (10) of the stepped planetary gearset (P1), wherein the at least one stepped planet wheel (12) of the stepped planetary gearset (P1) additionally meshes on a respective second toothing (14) with the ring wheel (9) of the stepped planetary gearset (P1).Motor vehicle transmission (3; 31; 33; 35; 37; 43) according to one of Claims 1 to 2, characterized in that the output shaft (7) is coupled to an input element (20) of a differential gearset (21) which operatively connects the output shaft (7) to two output shafts (22, 23).Motor vehicle transmission (3; 31; 33; 35; 37; 43) according to Claim 3 and according to Claim 2, characterized in that the differential gearset (21) is located axially overlapping with the ring gear (9) of the stepped planetary gearset (P1) and radially on the inside of the tooth mesh of the at least one stepped planet gear (12) of the stepped planetary gearset (P1) with the ring gear (9) of the stepped planetary gearset (P1).Motor vehicle transmission (43) according to Claim 3 or 4, characterized in that the differential gearset (21) is arranged axially covering and radially inside the planetary gearset (P2).Motor vehicle transmission (3; 31; 33; 35) according to one of the preceding claims, characterized in that the first element (E12) of the planetary gear set (P2) is the sun gear (15) of the planetary gear set (P2), whereas the second element (E22) of the planetary gear set (P2) is the planet carrier (16) of the planetary gear set (P2) when the planetary gear set (P2) is designed as a minus planetary set and the ring gear of the planetary gear set when the planetary gear set is designed as a plus planetary set, and wherein the third element (E32) of the planetary gear set (P2) is the ring gear (17) of the planetary gear set (P2) when the planetary gear set (P2) is designed as a minus planetary set and the planet carrier of the planetary gear set when the planetary gear set is designed as a plus planetary set.Motor vehicle transmission (37; 43) according to one of Claims 1 to 5, characterized in that the third element (E32) of the planetary gear set (P2) is the sun wheel (41) of the planetary gear set (P2), whereas the second element (E22) of the planetary gear set (P2) is the planet carrier (40) of the planetary gear set (P2) when the planetary gear set (P2) is designed as a minus planetary set and the ring wheel of the planetary gear set when the planetary gear set is designed as a plus planetary set, and wherein the first element (E12) of the planetary gear set (P2) is the ring wheel (38) of the planetary gear set (P2) when the planetary gear set (P2) is designed as a minus planetary set and the planet carrier of the planetary gear set when the planetary gear set is designed as a plus planetary set.Motor vehicle transmission (3; 31; 33; 35; 37; 43) according to one of the preceding claims, characterized in that the first shift element (A) and the second shift element (B) are formed by a common shift device (24) which has a coupling element (25), wherein the coupling element (25) can be positioned in each case in a first shift position and in a second shift position, wherein the coupling element (25), in the first shift position, functionally represents an actuated state of the first shift element (A) and connects the second element (E21) of the stepped planetary gearset (P1) to the first element (E12) of the planetary gearset (P2) in a rotationally fixed manner, and wherein the coupling element (25) in the second shift position functionally depicts an actuated state of the second shift element (B) and brings the third element (E31) of the stepped planetary gearset (P1) into connection with the first element (E12) of the planetary gearset (P2) in a rotationally fixed manner.Motor vehicle transmission (3; 31; 33; 35; 37; 43) according to Claim 8, characterized in that the coupling element (25) is guided in a rotationally fixed manner in the two shift positions and, in the event of an axial displacement between the two shift positions, on a first toothing (26) which is connected in a rotationally fixed manner to the first element (E12) of the planetary gear set (P2), wherein the coupling element (25), in the first shift position, additionally encloses a second toothing (28) which is connected in a rotationally fixed manner to the second element (E21) of the stepped planetary gear set (P1), and wherein the coupling element (26), in the second shift position, encloses a third toothing (29) which is connected in a rotationally fixed manner to the third element (E31) of the stepped planetary gear set (P1).Motor vehicle transmission (31; 33) according to one of the preceding claims, characterized in that a parking lock element (P) is additionally provided, which in an actuated state fixes the output shaft (7) directly or indirectly.Motor vehicle transmission (31; 33) according to Claim 10, characterized in that the parking lock element (P) is arranged in the power flow between two (E12, E32; E12, E22) of the elements (E21, E22, E32) of the planetary gear set (P2) and, in an actuated state, connects these two elements (E12, E32; E12, E22) of the planetary gear set (P2) to one another in a rotationally fixed manner.Motor vehicle transmission (31; 33) according to Claim 10 or 11 and according to one of Claims 3 to 5, characterized in that the parking lock element (P) is arranged axially covering and radially surrounding the differential gearset (21).Drive unit (1; 30; 32; 34; 36; 42; 49) for an at least partially electrically driven motor vehicle, comprising at least one electric machine (2) and a motor vehicle transmission (3; 31; 33; 35; 37; 43) according to one or more of claims 1 to 12, wherein a respective rotor (5) of the at least one electric machine (2) is coupled to the drive shaft (6) of the motor vehicle transmission (3; 31; 33; 35; 37; 43).Drive unit (1; 30; 32; 34; 36; 42; 49) according to claim 13, characterized in that the stepped planetary gearset (P1) of the motor vehicle transmission (3; 31; 33; 35; 37; 43) is placed axially between the at least one electric machine (2) and the planetary gearset (P2) of the motor vehicle transmission (3; 31; 33; 35; 37; 43).Electrically drivable motor vehicle drive axle (46) for an at least partially electrically driven motor vehicle, comprising a drive unit (1; 30; 32; 34; 36; 42; 49) according to claim 13 or 14.Hybrid or electric vehicle (44) comprising a drive unit (1; 30; 32; 34; 36; 42; 49) according to claim 13 or 14 or a motor vehicle drive axle (46) according to claim 15.Method for operating a motor vehicle transmission (3; 31; 33; 35; 37; 43) according to one or more of Claims 1 to 12, - wherein a first gear (G1) is shifted between the drive shaft (6) and the output shaft (7) by representing an actuated state of the first shift element (A), - and wherein a second gear (G2) is shifted between the drive shaft (6) and the output shaft (7) by representing an actuated state of the second shift element (B).

Images