Three-speed electric transmission

Abstract

The present invention relates to a transmission (16) for a motor vehicle drive train (12) of a motor vehicle (10), comprising: a transmission input shaft (22) for operatively connecting the transmission (16) to a drive engine (14) of the motor vehicle (10); spur gear pairs (ST1 a / ST1b, ST2a / ST2b) arranged in a plurality of gear set planes for forming gear stages; a planetary gear set (RS1) comprising a ring gear (34), a planet gear carrier, and a sun gear for forming the gear stages; a gearshift device with a shifting element (SE) for engaging the gear stages; a first intermediate shaft (24) which is drivingly connected to a first gear pair (ST1 a / ST1b, ST2a / ST2b) and a first planetary gear set element; a second intermediate shaft (26) which is drive-effectively connected to a second gear pair (ST1 a / ST1b, ST2a / ST2b) and is drive-effectively connectable to a second planetary gear set element;and an output shaft (38) with an output (32) that is drivingly connected to a third planetary gear set element; wherein the gear stages can be set by locking the second planetary gear set element or by coupling the second planetary gear set element to the first intermediate shaft (24) or the second intermediate shaft (26). The present invention further relates to a motor vehicle drive train with such a transmission, a method for operating a motor vehicle drive train, and a motor vehicle.

Description

[0001] The present invention relates to a transmission, in particular an electric transmission, a motor vehicle drive train, a method for operating a motor vehicle drive train and a motor vehicle.

[0002] Spur gears have the advantage of a relatively simple design, as they use few moving parts and the externally toothed spur gears are comparatively easy to manufacture. A disadvantage is the small gear ratio that can be achieved in a single stage. In addition, a spur gear is larger and therefore heavier than, for example, a planetary gear with the same transmission power. To achieve large gear ratios with a pair of spur gears, the circumference of at least one gear is kept small, while the circumference of the second gear is kept large. The contact ratio, i.e. the number of meshing teeth, becomes smaller the smaller at least one of the meshing gears is. It is therefore important to ensure that the individual teeth always mesh.

[0003] Vehicles are increasingly being equipped with purely electric drives, i.e. with an electric prime mover as the power source. Electric drives can contribute to reducing pollutant emissions because the electrical energy can be generated in a way that is at least partially CO2-neutral. Drivetrains with an electric prime mover and a simple one- or two-speed gearbox have largely become the norm. Very high speed ranges can be covered, for example, when electric prime movers are used, electric prime movers are known to reach up to 15,000 or 20,000 revolutions per minute. The gearboxes are subjected to enormous stresses in this case. However, due to the high speed range, gearboxes with just a few gears are usually sufficient to cover the speed range of an electric vehicle, especially an electric passenger car.On the one hand, it is known to use powerful, heavy, and large electric motors as prime movers capable of generating high torque. It is also known to use smaller, high-speed electric motors that are reduced by a gearbox or a simple input gear. This allows for the creation of a weight-efficient automotive drivetrain.

[0004] One advantage of all-electric drives is that the high speed range requires only a few gear ratios in a transmission, allowing for comparatively simple transmissions. This leads to a loss of driving comfort, as high speeds are generally perceived as unpleasant. Furthermore, shifting comfort is reduced with simple transmissions. For cost and weight reasons, non-powershift transmissions are therefore usually used, resulting in a loss of drive power during gear changes in such a simple transmission.

[0005] Against this backdrop, a specialist faces the task of creating a cost-effective transmission, preferably for an electric drive. In particular, the goal is to achieve high efficiency and comfort while maintaining technically simple assembly.

[0006] The above task is solved by a transmission for a motor vehicle drive train of a motor vehicle, with: a transmission input shaft for operatively connecting the transmission to a drive engine of the motor vehicle; spur gear pairs arranged in several gear set levels to form gear stages; a planetary gear set comprising a ring gear, a planetary gear carrier and a sun gear, for forming the gear stages; a gearshift device with a switching element for engaging the gears; and a first intermediate shaft drivingly connected to a first spur gear pair and a first planetary gear set element; a second intermediate shaft which is drive-connected to a second spur gear pair and is drive-connectable to a second planetary gear set element; and an output shaft with an output, which is drivingly connected to a third planetary gear set element, wherein the gear stages can be set by fixing the second planetary gear set element or by coupling the second planetary gear set element to the first or second intermediate shaft.

[0007] The above object is further achieved by a motor vehicle drive train for a motor vehicle, comprising: a gearbox as previously defined; and a drive machine that is drivingly connected to the transmission input shaft.

[0008] Furthermore, the problem is solved by a method for operating a motor vehicle drive train as previously defined.

[0009] The above object is finally achieved by a motor vehicle having a motor vehicle drive train as previously defined and an energy storage device for storing energy to supply the electric drive machine.

[0010] Preferred embodiments of the invention are described in the dependent claims. It is understood that the features mentioned above and those to be explained below can be used not only in the respective combinations specified, but also in other combinations or alone, without departing from the scope of the present invention. In particular, the motor vehicle drive train, the motor vehicle, and the method can be designed according to the embodiments described for the transmission in the dependent claims.

[0011] A transmission input shaft can be used to create a compact, efficient transmission. In particular, the transmission input shaft is designed to be connected directly to a rotor shaft of a preferably electric drive motor. Spur gear pairs arranged in multiple gear set levels in combination with a planetary gear set can create a compact transmission with an advantageous gear ratio spread. Intermediate shafts that are connected to the spur gear pairs and can be connected to planetary gear set elements by means of preferably exactly a single gear shift device can create a compact transmission with a wide range of functions. In particular, a transmission can be created by means of which exactly three gear stages can be set. By appropriately selecting the individual gear ratios, a uniform gear ratio can be achieved by means of the transmission.The transmission described can be used both as a central drive and as an axle drive. Preferably, the transmission has a single output shaft, a single shift element, two spur gear pairs, and a single planetary gear set.

[0012] In a preferred embodiment, the transmission input shaft comprises exclusively fixed gears. Particularly preferably, the complete transmission comprises exclusively fixed gears. This allows for the creation of a simple, cost-effective, and compact transmission. In particular, the transmission input shaft can be manufactured efficiently and cost-effectively. The transmission can be assembled in just a few steps and with minimal effort.

[0013] In a further advantageous embodiment, the first planetary gear set element is the sun gear of the planetary gear set. Additionally or alternatively, the second planetary gear set element is the ring gear of the planetary gear set. Further additionally or alternatively, the third planetary gear set element is the planetary gear carrier. This allows the planetary gear set to be advantageously integrated into the transmission. In particular, such an integration enables an advantageous transmission of the drive power through the interaction of the spur gear pairs with the planetary gear set.

[0014] In a further advantageous embodiment, the second intermediate shaft is designed as a hollow shaft and surrounds the first intermediate shaft at least in sections. The advantageous design of the second intermediate shaft and the advantageous arrangement increase the compactness of the transmission. The available installation space can be optimally utilized.

[0015] Further preferably, the transmission input shaft is a rotor shaft of the drive motor. Alternatively, the transmission input shaft is connected to the rotor shaft of the drive motor by means of a further spur gear pair, a gear chain, or a traction drive. Further alternatively, a gear of a spur gear pair for setting the gear stages engages with a gear arranged on the rotor shaft of the drive motor in order to drive-connect the transmission input shaft to the drive motor. The above-mentioned alternative embodiments allow different geometries for the transmission to be realized while maintaining essentially the same mode of operation. Consequently, a transmission individually adapted to the available installation space can be created in a technically simple manner.

[0016] In a particularly preferred embodiment, the transmission has precisely one shifting element, which preferably comprises a shift sleeve and an actuator, as well as three linear positions. This allows a technically simple sequential shifting sequence to be established with the shifting element. In particular, control and actuation of the shifting element are simplified, since shifting preferably only needs to be performed in a linear direction to establish different gear ratios with the transmission.

[0017] Further preferably, the transmission comprises exactly two spur gear pairs and exactly one planetary gear set for establishing preferably exactly three gear stages. This allows for the creation of an advantageously compact transmission with sufficient gear ratio spread and sufficient driving comfort for a preferably electric drive motor.

[0018] In a particularly preferred embodiment, the spur gear pairs are arranged upstream of the planetary gear set in the direction of power flow. The power direction runs from the drive engine to the driven wheels. This advantageous arrangement allows the drive power to be initially pre-ratioed using one spur gear pair or both spur gear pairs of the preferably exactly two spur gear pairs to set the gear stages and then subsequently re-ratioed in combination with the planetary gear set. In addition, the radial compactness of the transmission can be increased because the spur gear stages preferably have a greater radial extent than the planetary gear set, so that the entire radial extent of the transmission can be defined by the spur gear pairs and the planetary gear set can preferably be arranged radially inside and axially offset from the spur gear pairs in the transmission.

[0019] In a further advantageous embodiment, an output shaft is drive-effectively connected to a sun gear of a first differential planetary gear set. In addition, a planet gear carrier of the first differential planetary gear set is drive-effectively connected to a first wheel shaft in order to transmit drive power to a first wheel of the motor vehicle. Furthermore, a ring gear of the first differential planetary gear set is drive-effectively connected to a sun gear of a second differential planetary gear set. A planet gear carrier of the second differential planetary gear set is fixed. In addition, a ring gear of the second differential planetary gear set is drive-effectively connected to a second wheel shaft in order to transmit drive power to a second wheel of the motor vehicle. Particularly preferably, at least one wheel shaft runs at least partially within the first intermediate shaft designed as a hollow shaft.This advantageous formation of a differential using two differential planetary gear sets allows for radial compactness of the drivetrain, since the two differential planetary gear sets are preferably arranged coaxially with the planetary gear set of the transmission. Furthermore, when forming such a differential, an additional gear ratio can be established with the differential.

[0020] In a further advantageous embodiment, the shifting element is designed to lock the first planetary gear set element in a first shift position, to drive-connect the second planetary gear set element to the transmission input shaft by means of a second spur gear pair in a second shift position, and to block the planetary gear set in a third shift position in order to drive-connect the output shaft to the first spur gear pair. This advantageous embodiment of the shifting element and the associated shift positions allows a gear stage, and in particular a main gear, to be set up with low transmission losses, since a blocked planetary gear set acts like a shaft and therefore causes little or no transmission losses.

[0021] In a particularly preferred embodiment of the motor vehicle drive train, the drive motor is designed as an electric drive motor. Electric drive motors offer the advantage that they can cover a wide speed range and provide high torque even at low speeds. Electric drive motors typically require only a few gear ratios to function as a drive for a motor vehicle. An electric drive motor can therefore advantageously be used with a transmission, as defined above, to create a compact and powerful motor vehicle drive train.

[0022] In a further advantageous embodiment, an output of the transmission can be drive-effectively connected to a motor vehicle axle, preferably as the main drive of the motor vehicle, wherein a further motor vehicle axle particularly preferably comprises an electric axle with a further drive motor. Alternatively, an output of the transmission can be connected to a motor vehicle axle, preferably to form an electric axle. This makes it possible to create a multifunctional motor vehicle drive train. On the one hand, the motor vehicle drive train is suitable as a standalone main drive that can be combined with an electric axle if required. On the other hand, a motor vehicle drive train itself can function as an electric axle and be combined with another main drive.

[0023] Locking an element of a planetary gear set is understood in particular as blocking the element's rotation about its axis of rotation. Preferably, the element is connected in a rotationally fixed manner to a static component such as a frame and / or a transmission housing by means of a switching element. It is also conceivable to brake the element to a standstill.

[0024] Interlocking a planetary gear set involves connecting two gears and / or the planetary gear carrier and a gear of the planetary gear set in a drive-effective manner, so that they rotate together at the same speed around the same point, preferably the center of the planetary gear set. When interlocking two gears and / or a planetary gear carrier and a gear of the planetary gear set, the planetary gear set preferably acts like a shaft; in particular, no gear ratio is transmitted within the planetary gear set.

[0025] In this context, "drive-effectively connected" refers in particular to a non-switchable connection between two components, which is intended for the permanent transmission of a rotational speed, torque, and / or drive power. The connection can be established either directly or via a fixed transmission ratio. The connection can be established, for example, via a fixed shaft, a gearing, in particular a spur gear, and / or a belt drive, in particular a traction drive.

[0026] In this context, "drive-connectable," "can be connected to a drive," or "is designed for a drive-connected connection" refers, in particular, to a switchable connection between two components, which, in a closed state, is intended for the temporary transmission of a rotational speed, a torque, and / or a drive power. In an open state, the switchable connection preferably temporarily transmits essentially no rotational speed, no torque, and / or no drive power.

[0027] In this context, an actuator is, in particular, a component that converts an electrical signal into a mechanical movement. Actuators used with dual switching elements preferably perform movements in two opposite directions, switching one switching element of the dual switching element in the first direction and switching the other switching element in the second direction.

[0028] A gear change occurs, in particular, by disengaging a shifting element and / or a clutch from one shifting point and simultaneously engaging one or the shifting element and / or the clutch with respect to a shifting point for the next higher or lower gear. In the second shift position, the torque from the first shift position is preferably transferred gradually until, at the end of the gear change, the entire torque is transferred to the second shift position. With prior synchronization, a gear change can occur more quickly; positive-locking shift elements can preferably be used.

[0029] An electric vehicle axle, or simply an electric axle, is preferably a non-main drive axle of a motor vehicle, in which drive power can be transferred to the wheels of the motor vehicle by means of an electric drive motor. It is understood that the electric drive motor can also be connected via a transmission. Traction can be fully or partially maintained by means of an electric axle when a gear change occurs in the transmission for a main drive axle. Furthermore, all-wheel drive functionality can be implemented at least partially by means of an electric axle.

[0030] The invention is described and explained in more detail below using selected embodiments in conjunction with the accompanying drawings. They show: Fig. 1 a schematic plan view of a motor vehicle with a motor vehicle drive train according to the invention; Fig. 2 a schematic representation of the transmission according to the invention; Fig. 3 a schematic overview of the switching states of a transmission according to the invention; Fig. 4 a schematic representation of another embodiment of a transmission according to the invention; Fig. 5 a schematic representation of another embodiment of a transmission according to the invention; Fig. 6 a schematic representation of another embodiment of a transmission according to the invention; and Fig. 7a to 7c schematic representations of switching positions.

[0031] In Fig. 1 schematically shows a motor vehicle with a motor vehicle drive train 12. The motor vehicle drive train 12 has an electric drive motor 14 and a transmission 16. In the example shown, the transmission 16 and the electric drive motor 14 are connected to a front axle of the motor vehicle 10 and form a main drive of the motor vehicle 10. Another purely electric drive is operatively connected to the rear axle of the motor vehicle 10 to form an electric axle 18. It is understood that a reverse connection can also be made, so that the electric axle is connected to the front axle of the motor vehicle 10 and the rear axle of the motor vehicle 10 comprises the motor vehicle drive train 12. By means of the motor vehicle drive train 12, drive power of the electric drive motor 14 is supplied to the wheels of the motor vehicle 10.The motor vehicle 10 further comprises an energy storage device 20 for storing energy that serves to supply the electric drive motor 14.

[0032] In Fig. Figure 2 schematically shows a first embodiment of a motor vehicle drive train 12 with a transmission 16. The transmission 16 has a transmission input shaft 22 that is drivingly connected to an electric drive motor 14. In the example shown, the transmission input shaft 22 forms a rotor shaft of the electric drive motor 14.

[0033] The transmission 16 further comprises a first intermediate shaft 24 and a second intermediate shaft 26. The second intermediate shaft 26 is designed as a hollow shaft and surrounds the first intermediate shaft 24 at least in sections.

[0034] The transmission input shaft 22 is drivingly connected to the first intermediate shaft 24 by means of a first spur gear pair comprising two spur gears ST1a, ST1b.

[0035] The second intermediate shaft 26 is drivingly connected to the transmission input shaft 22 by means of a second spur gear pair comprising two spur gears ST2a and ST2b. In the example shown, the transmission 16 has exactly two spur gear pairs.

[0036] The first intermediate shaft 24 is also connected to a sun gear of a planetary gear set RS1.

[0037] A ring gear 34 of the planetary gear set RS1 is drive-connected to a shifting element SE by means of another shaft 30. The ring gear 34 always remains drive-connected to the shifting element SE, regardless of the shift position of the shifting element SE.

[0038] The switching element SE can assume various switching positions and control switching points designated A to C. In addition, the switching element SE can preferably also assume a neutral position.

[0039] In a first shift position, the shift element SE controls the first shift point A and connects a locking shaft 28 to the ring gear 34 of the planetary gear set RS1 in a drive-effective manner. The planetary gear set RS1 is therefore locked and establishes a transmission ratio for the drive power. The electric drive motor 14 provides drive power via the first spur gear pair and the first intermediate shaft 24. The sun gear of the planetary gear set RS1 drives the planetary gear set RS1, with the planetary gear set RS1 driving a planetary gear 36 and ultimately a planetary gear carrier via the locked ring gear 34. This planetary gear carrier then provides drive power to an output shaft 38 and ultimately to an output 32 of the transmission 16.

[0040] In a second shift position, the shift element SE controls the second shift point B and drive-connects the second intermediate shaft 26 to the ring gear 34 of the planetary gear set RS1. The planetary gear set RS1 functions as a mixed transmission, with the sun gear of the planetary gear set RS1 being driven as previously described, and the ring gear 34 being driven by the electric drive motor 14 via the second spur gear pair comprising the spur gears ST2a and ST2b.

[0041] In a third shift position, the shift element SE controls the third shift point C and locks the planetary gear set RS1, in which the sun gear is connected to the ring gear 34 in a drive-effective manner. Consequently, the gear ratio up to the output 32 is determined by the first spur gear pair comprising the spur gears ST1a and ST1b.

[0042] In Fig. Figure 3 shows a schematic overview 40 of the individual gear ratios and shift states. An "X" here means that the shift element SE controls the corresponding shift point, i.e., connects the ring gear 34 of the planetary gear set, as described above, to the individual components of the transmission 16. If no entry is present, this shift point is not drive-connected to the ring gear 34 of the planetary gear set RS1 by the first shift element SE.

[0043] To set a first gear, the first shift point A is activated by means of the shift element SE. A second gear is set by activating the second shift point B. A third gear is set by activating the third shift point C.

[0044] A particular advantage here is that the RS1 planetary gear set is locked by controlling shift point C, thus causing little or no transmission losses. This allows the highest gear to be operated efficiently.

[0045] In Fig. 4 the gearbox is according to the Fig. 2 with a differential formed by two differential planetary gear sets RS2, RS3. The remaining transmission components are identical to those in Fig. 2 and will not be explained again.

[0046] A planet carrier of planetary gear set RS1 is drive-connected to a ring gear of the first differential planetary gear set RS2. A planet carrier of the first differential planetary gear set RS2 is drive-connected to an unspecified wheel shaft of the motor vehicle. A ring gear of the first differential planetary gear set RS2 is drive-connected to a sun gear of the second differential planetary gear set RS3. A planet carrier of the second differential planetary gear set RS3 is fixed. A ring gear of the second differential planetary gear set RS3 is drive-connected to a second wheel shaft of the motor vehicle.

[0047] This allows a differential to be formed by means of the two differential planetary gear sets RS2, RS3, by means of which a subsequent transmission of the drive power is possible.

[0048] In Fig. 5 shows a further variant of a transmission 16 according to the invention in a motor vehicle drive train 12. In contrast to the Fig. In the embodiment shown in Figure 2, the electric drive motor 14 is drivingly connected to the transmission input shaft 22 by means of a further spur gear pair (not further designated) consisting of two fixed gears.

[0049] In addition, a differential of the output 32 is in contrast to the one in Fig. 4, the transmission 16 is no longer formed by two differential planetary gear sets, but instead comprises a bevel gear differential. The remaining elements in the transmission 16 are essentially identical to the previously described embodiments and will not be explained again.

[0050] In Fig. 6 shows a further embodiment of a transmission 16 according to the invention in a motor vehicle drive train 12. In contrast to the Fig. 5, the transmission 16 does not comprise an additional spur gear pair for connecting the electric drive motor 14. The electric drive motor 14 is drivingly connected to the gear ST1a of the first spur gear pair arranged on the transmission input shaft 22 by means of a connecting gear arranged on the rotor shaft of the electric drive motor 14.

[0051] In the Fig. 7a to 7c correspond to overview 40 according to the Fig. 3 shows the individual switching positions of the switching element SE for setting the gear steps in detail. The design of the transmission 16, based on which these settings are shown, corresponds to the transmission 16 according to Fig. 2.

[0052] In Fig. Figure 7a shows a first switching position of the switching element SE, which serves to establish the first gear. The switching element SE is located on the left in the figure and controls switching point A. The switching element SE connects the locking shaft 28, which is connected in a rotationally fixed manner, for example, to a housing of the transmission 16, with the ring gear 34 of the planetary gear set RS1.

[0053] In Fig. 7b shows a switching position which is used to set the second gear. In this case, the switching element SE is in the Fig. 7a, the gear is shifted slightly to the left and controls the switching point B, so that the second intermediate shaft 26 is connected in a drive-effective manner to the ring gear 34 of the planetary gear set RS1.

[0054] Consequently, the planetary gear set RS1 is supplied with drive power on the one hand by means of the first intermediate shaft 24 and the first spur gear pair comprising the gears ST1a, ST1b and by means of the second intermediate shaft 26 via the second spur gear pair comprising the gears ST2a and ST2b, translates this drive power and finally supplies this translated drive power to the planet gear carrier, the output shaft 38 and the output 32.

[0055] Fig.Figure 7c shows a shift position of the shift element SE, which serves to establish the third gear. Here, the shift element SE is shifted toward the planetary gear set RS1 and locks it. It thus controls shift point C. The lock is established by connecting the first intermediate shaft 24, i.e., the sun gear, to the ring gear 34 of the planetary gear set RS1 in a drive-effective manner. Consequently, the gear ratio established toward the output 32 is established by the first spur gear pair comprising the gears ST1a, ST1b.

[0056] The invention has been comprehensively described and explained with reference to the drawings and the description. The description and explanation are to be understood as exemplary and not restrictive. The invention is not limited to the disclosed embodiments. Other embodiments or variations will become apparent to those skilled in the art upon use of the present invention and upon careful analysis of the drawings, the disclosure, and the following claims.

[0057] In the patent claims, the words "comprising" and "having" do not exclude the presence of further elements or steps. The undefined article "a" or "an" does not exclude the presence of a plurality. A single element or a single unit can perform the functions of several of the units recited in the patent claims. The mere mention of some measures in several different dependent patent claims should not be understood to mean that a combination of these measures cannot also be used advantageously. Reference symbols in the patent claims are not to be understood as limiting. A method for operating a motor vehicle drivetrain 12 can, for example, be implemented in the form of a computer program that is executed on a control unit for the motor vehicle drivetrain 12.A computer program may be stored / distributed on a non-volatile storage medium, such as optical storage or a solid-state drive (SSD). A computer program may be distributed together with hardware and / or as part of hardware, such as via the Internet or via wired or wireless communication systems. Reference symbol 10 motor vehicle 12 Automotive powertrain 14 Drive machine 16 gearboxes 18 electric axles 20 energy storage units 22 Gearbox input shaft 24 first intermediate shaft 26 second intermediate shaft 28 Locking shaft 30 more waves 32 downforce 34 ring gear 36 Planetary gear 38 Output shaft 40 Overview RS1 planetary gear set RS2 first differential planetary gear set RS3 second differential planetary gear set A - C switching points SE switching element ST1a gear ST1b gear ST2a gear ST2b gear

Claims

[1] Transmission (16) for a motor vehicle drive train (12) of a motor vehicle (10), comprising: a transmission input shaft (22) for operatively connecting the transmission (16) to a drive engine (14) of the motor vehicle (10); spur gear pairs (ST1a / ST1b, ST2a / ST2b) arranged in several gear set levels to form gear steps; a planetary gear set (RS1) comprising a ring gear (34), a planetary gear carrier and a sun gear, for forming the gear stages; a gearshift device with a shift element (SE) for engaging the gears; a first intermediate shaft (24) which is drivingly connected to a first gear pair (ST1 a / ST1b, ST2a / ST2b) and a first planetary gear set element; a second intermediate shaft (26) which is drivingly connected to a second gear pair (ST1 a / ST1b, ST2a / ST2b) and is drivingly connectable to a second planetary gear set element; and an output shaft (38) with an output (32) which is drivingly connected to a third planetary gear set element; wherein the gear stages can be set by fixing the second planetary gear set element or by coupling the second planetary gear set element to the first intermediate shaft (24) or the second intermediate shaft (26). [2] Transmission (16) according to claim 1, wherein the transmission input shaft (22) has exclusively fixed gears. [3] Transmission (16) according to one of the preceding claims, wherein the first planetary gear set element is the sun gear of the planetary gear set (RS1); the second planetary gear set element is the ring gear (34) of the planetary gear set (RS1); and / or the third planetary gear set element is the planet gear carrier of the planetary gear set (RS1). [4] Transmission (16) according to one of the preceding claims, wherein the second intermediate shaft (26) is designed as a hollow shaft and surrounds the first intermediate shaft (24) at least in sections. [5] Transmission (16) according to one of the preceding claims, wherein the transmission input shaft (22) is a rotor shaft of the drive machine (14); the transmission input shaft (22) is connected to a rotor shaft of the drive machine (14) by means of a further spur gear pair, a gear chain or a traction mechanism; or a gearwheel (ST1a, ST2a) of a gearwheel pair (ST1a / ST1b, ST2a / ST2b) for setting the gear stages meshes with a gearwheel arranged on a rotor shaft of the drive motor (14) in order to drive-effectively connect the transmission input shaft (22) to the drive motor (14). [6] Transmission (16) according to one of the preceding claims, wherein the transmission (16) has exactly one switching element (SE), which preferably comprises a shift sleeve and an actuator as well as three linear positions. [7] Transmission (16) according to one of the preceding claims, wherein the transmission (16) comprises exactly two gear pairs (ST1 a / ST1b, ST2a / ST2b) and a planetary gear set (RS1) for establishing preferably exactly three gear stages. [8] Transmission (16) according to the preceding claim, wherein in the power flow direction the gear pairs (ST1a / ST1b, ST2a / ST2b) are arranged in front of the planetary gear set (RS1). [9] Transmission (16) according to one of the preceding claims, wherein the output shaft (38) is drivingly connected to a sun gear of a first differential planetary gear set (RS2); a planetary gear carrier of the first differential planetary gear set (RS2) is drivingly connected to a first wheel shaft in order to transmit drive power to a first wheel of the motor vehicle (10); a ring gear of the first differential planetary gear set (RS2) is drive-connected to a sun gear of a second differential planetary gear set (RS3); a planetary gear carrier of the second differential planetary gear set (RS3) is fixed; and a ring gear of the second differential planetary gear set (RS3) is drivingly connected to a second wheel shaft in order to transmit drive power to a second wheel of the motor vehicle (10). [10] Transmission (16) according to one of the preceding claims, wherein the switching element (SE) is designed to to fix the first planetary gear set element in a first switching position; in a second switching position, to drive-connect the second planetary gear set element to the transmission input shaft (22) by means of a second gear pair (ST1 a / ST1b, ST2a / ST2b); in a third switching position, to block the planetary gear set (RS) in order to connect the output shaft to the first gear pair (ST1 a / ST1b, ST2a / ST2b) in a drive-effective manner. [11] Motor vehicle drive train (12) for a motor vehicle (10), comprising: a transmission (16) according to one of the preceding claims; and a drive motor (14) which is drivingly connected to the transmission input shaft (22). [12] Motor vehicle drive train (12) according to claim 11, wherein the drive machine (14) is designed as an electric drive machine. [13] Motor vehicle drive train (12) according to claim 11 or 12, wherein an output (32) of the transmission (16) is driveably connectable to a motor vehicle axle, preferably as the main drive of the motor vehicle (10), and a further motor vehicle axle particularly preferably comprises an electric axle (18) with a further drive motor; or an output (32) of the transmission (16) is driveably connectable to a motor vehicle axle to form an electric axle (18). [14] Method for operating a motor vehicle drive train (12) according to one of claims 11 to 13. [15] Motor vehicle (10) with: a motor vehicle drive train (12) according to one of claims 12 to 13; and an energy storage device (20) for storing energy to supply the electric drive machine (14).

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