WO2023208545A1

WO2023208545A1 - Gearbox mechanism and drivetrain for a vehicle

Info

Publication number: WO2023208545A1
Application number: PCT/EP2023/058844
Authority: WO
Inventors: Thomas Martin; Michael Wechs; Fabian Kutter
Original assignee: Zf Friedrichshafen Ag
Priority date: 2022-04-29
Filing date: 2023-04-04
Publication date: 2023-11-02
Also published as: DE102022204227A1

Abstract

The invention relates to a gearbox mechanism (3) for a drivetrain (2) of an at least partly electrically driven vehicle (1), the gearbox mechanism comprising a stepped planetary gearset (4), a first gearshift element (A), a second gearshift element (B) and a third gearshift element (C), wherein the stepped planetary gearset (4) has a first sun gear (7a), a second sun gear (7b), a first ring gear (8a), a second ring gear (8b) and a plurality of stepped planetary gears (10) which are rotatably mounted on a first planetary carrier (9), wherein the first ring gear (8a) is connected to a housing (13) for conjoint rotation, wherein the second ring gear (8b) is connected to an output shaft (12) of the gearbox mechanism (3) for conjoint rotation, wherein the first gearshift element (A) is designed, in a closed state, to connect the first sun gear (7a) to a rotor (19) of an electric machine (11) for conjoint rotation, wherein the second gearshift element (B) is designed, in a closed state, to connect the second sun gear (7b) to the rotor (19) of the electric machine (11) for conjoint rotation, wherein the third gearshift element (C) is designed, in a closed state, to connect the planetary carrier (9) to the rotor (19) of the electric machine (11) for conjoint rotation, and wherein one of the three gearshift elements (A-C) is in the closed state in order to rotationally drive the output shaft (12). The invention also relates to a drivetrain (2) comprising such a gearbox mechanism (3).

Description

Transmission and drive train for a vehicle

The invention relates to a transmission for a drive train of an at least partially electrically driven vehicle. The invention further relates to a drive train comprising such a transmission.

From the publication WO 2014/139744 A1 a drive train for a vehicle is known, with at least one electric drive, which can be coupled via a drive shaft with at least a first gear ratio and a second gear ratio. At least one switching device is provided for switching the gear ratio stages, wherein the switching device for carrying out power shifts comprises at least one positive switching element and at least one frictional switching element. Each of the transmission stages can be switched with the positive switching element, with at least one of the transmission stages being switchable both with the positive switching element and with the frictional switching element.

The object of the present invention is to propose a 3-speed transmission and an alternative drive train with a 3-speed transmission, each of which achieves a high conversion and at the same time increased spread. This object is achieved according to a first aspect of the invention with a transmission according to claim 1. The object is further achieved according to a second aspect of the invention with a drive train according to claim 6. Advantageous refinements result from the dependent claims.

According to a first aspect of the invention, a transmission for a drive train of an at least partially electrically driven vehicle comprises a stepped planetary gear set, a first gear shift element, a second gear shift element and a third gear shift element, the stepped planetary gear set having a first sun gear, a second sun gear, a first ring gear, a second Ring gear and a plurality of stepped planetary gears rotatably mounted on a first planet carrier, the first ring gear being connected in a rotationally fixed manner to a housing, the second ring gear being connected in a rotationally fixed manner with an output shaft of the transmission, wherein the first gear shift element is designed to rotate the first sun gear with a rotor of an electric machine in a closed state, wherein the second gear shift element is configured to rotate the second sun gear to the rotor of the electric machine in a closed state, wherein the third gearshift element is designed to rotate the first planet carrier with the rotor of the electric machine in a closed state, and one of the three gearshift elements is in the closed state for rotationally driving the output shaft. By means of such a transmission, a 3-speed drive of the vehicle is possible in a simple manner, with the transmission advantageously enabling a comparatively high conversion of greater than 1 and at the same time a comparatively high spread of greater than 3. Another advantage of such a design of the transmission is the high degree of efficiency that can be achieved.

The term “spread”, also known as the ratio spread, is understood to mean the adjustment range as the ratio of the maximum to the minimum ratio. The transmission spread indicates the ratio between the largest and smallest gear ratio. The term “high conversion” means an increased translation level of the entire system. In other words, the drive has a comparatively high gear ratio in all gears or gear stages.

An “active connection” or “drive-effective connection” is understood to be a connection between two torque-carrying parts that allows torque or power to be transmitted between these parts. In particular, both parts are mounted so that they can rotate accordingly. Connections that have a driving effect include those that do not have a gear ratio or intermediate components, as well as those that have a gear ratio or intermediate components. For example, further shafts and/or gears can be arranged to have a driving effect between two shafts or two gears. Such a connection can also be a rotation-proof connection.

To form one of the three gears, either the first sun gear or the second sun gear or the first planet carrier is placed over the respective one Gear shifting element connected to an electrical machine, in particular to the rotor or a rotor shaft of the electrical machine. The electric machine is part of a drive train according to the invention, which will be discussed below. The rotor shaft of the electrical machine serves as the output shaft of the electrical machine when the electrical machine is in rotor operation. The first sun gear, the second sun gear or the first planet carrier are connected in a rotationally fixed manner to input shafts of the stepped planetary gear set or to respective input shafts during rotor operation of the electric machine. During rotor operation of the electric machine, for example, electrical energy is fed into the electric machine from an energy storage device, in particular a battery or the like, which results in a rotation of the rotor relative to a stator of the electric machine to generate drive power, the drive power depending on the switching position of the respective gear shifting element is provided for the rotational drive of the first or second sun gear or the first planet carrier. In generator operation, however, electrical energy is generated with the electrical machine. The output shaft of the transmission functions as an input shaft in generator operation of the electric machine, whereas the first sun gear, the second sun gear or the first planet carrier via the respective activated or coupled gearshift element are to be understood as output shafts of the transmission, with a drive power of the vehicle via the transmission and the respective gear shifting element is guided into the electrical machine, so that electrical energy is generated with the electrical machine, which can be fed into the energy storage for storage. In generator operation, the power is introduced into the electric machine, for example from one or more rotating wheels of the vehicle via the transmission and the respective gearshift element.

The term “at least indirectly” means that two components are connected to one another via at least one further component that is arranged between the two components or are directly and therefore directly connected to one another. Therefore, further components can be arranged between shafts or gears, which are operatively connected to the shaft or gear. A “shaft”, be it an input shaft, an output shaft, an output shaft, an intermediate shaft or the like, is to be understood as a rotatable component of the transmission, via which the associated components of the transmission are rotatably connected to one another. The respective shaft can connect the components to one another axially or radially or both axially and radially. A shaft does not only mean, for example, a cylindrical, rotatably mounted machine element for transmitting torque, but rather it also includes general connecting elements that connect individual components or elements to one another, in particular connecting elements that rotate several elements together.

The first sun gear is in mesh with a first gear of the respective stepped planetary gear of the stepped planetary gear set. The respective stepped planetary gear has a second gear arranged coaxially and rotated relative to the first gear, which meshes with the second sun gear. The two gears of the respective stepped planetary gear have different diameters and numbers of teeth. In particular, the first gear has a larger diameter than the second gear. Gears that mesh with one another or mesh with one another transmit speed and torque via their interlocking teeth. Providing a stepped planetary gear set has the advantage that the first planet carrier does not need to be connected to other components of the transmission, thereby providing a cost-optimized transmission. In addition, regardless of whether the first, second or third gear shifting element is closed and the other gear shifting elements are open at the same time, the stepped planetary gear set has comparatively good mechanical parameters, i.e. speeds and torque, with a high conversion rate, while at the same time being highly efficient.

The first sun gear, the second sun gear and the first planet carrier are arranged, for example, coaxially and relatively rotatable to one another, with preferably one of the sun gears being passed axially at least partially through the other sun gear, and with the two sun gears being passed axially through the first planet carrier. Alternatively, the first planet carrier can be radial be guided within the two sun wheels. Therefore, at least one of the sun gears, preferably both sun gears depending on the design of the drive train, is connected to a respective hollow shaft. The first planet carrier can be connected to a hollow shaft or a solid shaft. The respective sun gear can have an associated input shaft designed as a hollow shaft, which is operatively connected to the first or second gear shifting element. The first planet carrier can also have an associated input shaft, which is operatively connected to the third gear shifting element.

While the first ring gear supports the drive torque on the housing, the second ring gear, depending on the switching position or state of the gear shifting elements, transmits a drive power with a respective gear ratio at least indirectly to the output shaft, which in turn is connected to at least one output shaft, preferably two output shafts, of the drive train of the vehicle. The output shaft or the output shafts is or are arranged coaxially to an output axis. Thus, at least one wheel of the vehicle is at least indirectly driven in rotation by the drive power generated by the electric machine and at least converted by the transmission via the output shaft and the output shaft or the output shafts. The respective wheel is operatively connected to the respective output shaft.

A gearshift element is to be understood as meaning a connecting part, by means of which at least one torque-transmitting part can be connected in a drive-effective manner to another torque-transmitting part or to a stationary or housing-fixed part. The respective gearshift element can be switched between at least one open and a closed state, wherein the gearshift element in the open state cannot transmit a torque or a speed between two parts interacting with the gearshift element, and wherein the gearshift element in the closed state transmits a torque and a speed between the can be transmitted to two parts interacting with the gearshift element. If there is a driving connection between two gear elements, torques and forces, and depending on the design of the gear elements possibly a speed, are transmitted from one gear element to the other gear element. When the first gear shift element is in the closed state or is switched to the closed state and the second and third gear shift elements are open, drive power is transmitted from the transmission input to the transmission output, or vice versa, in a first gear or a first gear stage, with a first gear ratio or a first gear ratio. The first sun gear or the input shaft, which is non-rotatably connected to the first sun gear, is thereby non-rotatably connected to the rotor of the electric machine, whereby the drive power is introduced into the transmission via the first sun gear. In the closed state of the first gear shift element, the second and third gear shift elements are in the open state in order to transmit the drive power with the first gear ratio to the output shaft via the second ring gear of the transmission. For example, a first gear ratio realized in first gear is greater than 1, with the first gear ratio being different from the second and third gear ratios described below in order to realize a 3-speed drive.

When the second gearshift element is in the closed state or is switched to the closed state and the first and third gearshift elements are open, drive power is transmitted from the transmission input to the transmission output, or vice versa, in a second gear or a second gear stage, with a second gear ratio or a second gear ratio. The second sun gear or the input shaft, which is non-rotatably connected to the second sun gear, is thereby non-rotatably connected to the rotor of the electric machine, whereby the drive power is introduced into the transmission via the second sun gear. In the closed state of the second gear shift element, the first and third gear shift elements are in the open state in order to transmit the drive power with the second gear ratio to the output shaft via the second ring gear of the transmission. For example, a second gear ratio realized in second gear is also greater than 1, with the second gear ratio being different from the first and the third gear ratio described below in order to realize the 3-speed drive. When the third gearshift element is in the closed state or is switched to the closed state and the first and second gearshift elements are open, drive power is transmitted from the transmission input to the transmission output, or vice versa, in a third gear or a third gear stage, with a third gear ratio or a third gear ratio. The first planet carrier or the input shaft connected in a rotationally fixed manner to the first planet carrier is thereby connected in a rotationally fixed manner to the rotor of the electric machine, whereby the drive power is introduced into the transmission via the first planet carrier. In the closed state of the third gear shift element, the first and second gear shift elements are in the open state in order to transmit the drive power with the third gear ratio to the output shaft via the second ring gear of the transmission. For example, a third gear ratio realized in third gear is also greater than 1, with the third gear ratio being different from the first and second gear ratios in order to realize the 3-speed drive. Therefore, to effectively drive the vehicle, either the first gear shift element, the second gear shift element or the third gear shift element is closed.

If all three gear shifting elements are open, no drive power is introduced into the transmission and therefore no drive power is transmitted to the output shaft of the transmission. The transmission is therefore in neutral. In contrast, if at least two or all three gear shifting elements are closed, rotation of the output shaft is blocked. In this respect, in order to implement a parking lock function, at least two of the gearshift elements can be in a closed state at the same time.

The first gear shift element and/or the second gear shift element and/or the third gear shift element is preferably designed as a non-positive shift element. In particular, the non-positive switching element can be designed as a friction switching element, in particular as a multi-disc clutch or cone clutch, in order to produce a non-positive connection between the rotor of the electric machine and the first sun gear or the second sun gear or the first planet carrier, depending on the switching position of the gear shifting elements. A A non-positive switching element is one that introduces a normal force onto two parts or surfaces of transmission elements that are to be connected to one another, with mutual displacement of the parts or surfaces being prevented as long as a counterforce essentially caused by static friction is not exceeded. This creates a frictional connection for transmitting torque between the transmission elements to be connected.

Advantageously, with the transmission according to the invention according to the first aspect of the invention, a power shift between the gears is possible, i.e. switching between a first, second and third gear, without the drive power on the output or on the output shaft being interrupted, in particular during a switching process. For this purpose, it is advantageous not necessary to provide separate power-shifting elements, but rather the transmission can be equipped with structurally simpler non-positive gear-shifting elements. For a traction load shift or a thrust load shift, it is necessary that at least one of the gear shift elements is designed as a non-positive gear shift element or as a friction shift element. In contrast, for a traction and thrust load shift using the gear shift elements, it is necessary that all gear shift elements are each designed as a non-positive gear shift element. In contrast, at least one of the other gear shifting elements can not be designed as a non-positive shifting element, but rather as a positive gear shifting element or claw shifting element. Thus, one gear shift element, preferably two gear shift elements, and preferably all gear shift elements can each be designed as a frictional shift element and carry out a power shift. A gear shift element that implements a power shift is a shift element that allows two gear elements to be connected to one another while a drive power, in particular a torque, is applied to one gear element, so that after closing the drive power is transmitted to the other gear element. It is not necessary to synchronize the speeds of the transmission elements involved before closing a powershift element.

Alternatively or additionally, the first gear shift element and/or the second gear shift element and/or the third gear shift element is a form-fitting one Switching element formed. A positive switching element can be designed, for example, as a claw switching element in order to produce a positive connection between the rotor of the electric machine and the first sun gear or the second sun gear, depending on the switching position of the gear shifting elements. A positive switching element is one in which two parts of the transmission interlock and form a positive connection for transmitting torque between two transmission elements. A positive switching element is more cost-effective and, above all, optimized in terms of efficiency compared to a non-positive switching element. In this sense, the respective gear shifting element is either a positive shifting element or a non-positive shifting element.

According to one embodiment of the invention, two of the three gear shifting elements are combined to form a double shifting element. This means that, depending on the embodiment, the first and second gearshift elements, the second and third gearshift elements or the first and third gearshift elements are arranged axially directly next to one another, with the respective two gearshift elements being combined to form a structural unit. This is particularly advantageous if both switching elements of the combined switching elements are designed as claw switching elements to realize a positive connection between the rotor of the electric machine and the first sun gear or the second sun gear or the first planet carrier. In this case, power shifting between the gears is not possible, but with such an arrangement and design of the gear shifting elements, axial installation space of the transmission can be saved. The design of the gear shift elements as claw shift elements also simplifies the implementation of the parking lock function, i.e. when the two gear shift elements combined to form a double shift element are transferred or are in the closed state.

A double switching element is generally understood to mean an arrangement of two switching elements that can be actuated alternatively by means of a single actuating device. Furthermore, a double switching element can have a neutral position in which none of the two switching elements of the double switching element is closed. The double switching element consequently has a first position in which a first switching element is closed, a second position in which a second switching element is closed, and a third position in which neither the first switching element nor the second switching element is closed, i.e. a neutral position. The double switching element has in particular a single switching fork and a single actuator for switching the two switching elements. This saves installation space, weight and transmission components.

According to a further embodiment, all gear shift elements are combined to form a triple shift element. This means that all gear shifting elements are arranged axially directly next to one another and combined to form a structural unit. This is particularly advantageous if all switching elements of the combined switching elements are designed as claw switching elements to realize a positive connection between the rotor of the electric machine and the first sun gear or the second sun gear or the first planet carrier. In this case, power shifting between the gears is not possible, but with such an arrangement and design of the gear shifting elements, axial installation space of the transmission can be saved. The design of the gear shift elements as claw shift elements also simplifies the implementation of the parking lock function, i.e. when the gear shift elements are or are in the closed state. Another advantage is that all switching elements can be controlled by a common actuator. In addition, such a design is advantageous when sequential switching between the individual gear stages is required, i.e. when switching from the first to the third gear stage, or vice versa, is not necessary.

A triple switching element is therefore to be understood as an arrangement of three switching elements that can be actuated alternatively or sequentially by means of a single actuating device. Furthermore, the triple switching element can have a neutral position in which none of the three switching elements is closed. The double switching element consequently has a first position in which a first switching element is closed, a second position in which a second switching element is closed, a third position in which a third switching element is closed, and a fourth Position in which neither the first switching element nor the second switching element nor the third switching element is closed, i.e. a neutral position.

According to a second aspect of the invention, a drive train for an at least partially electrically driven vehicle comprises a transmission according to the first aspect of the invention, as well as an electric machine, the rotor of which is connected in a rotationally fixed manner to an input shaft of the transmission. The input shaft is operatively connected to the three gearshift elements and, depending on the switching position of the gearshift elements, is connected in a rotationally fixed manner to the first sun gear, the second sun gear and/or the first planet carrier. Such a drive train is designed to be compact with the transmission according to the invention and achieves a comparatively high conversion of greater than 1 and at the same time a comparatively high spread of greater than 3.

The output shaft of the transmission preferably forms the input of a transmission gear downstream of the stepped planetary gear set. The transmission gear increases the transmission ratio of the drive. Due to the downstream arrangement of the transmission gear, the components of the stepped planetary gear set can be made comparatively small and compact.

The transmission gear can in principle be of any design. According to one exemplary embodiment, the transmission gear is designed as a spur gear stage. The spur gear stage can be designed in one, two or more stages. In a two-stage or multi-stage variant, one or more intermediate shafts can be provided, on which spur gears or stepped gears are also arranged. By means of a spur gear stage, in addition to a gear ratio change, an axis parallelism of the drive axle to an output axle can also be achieved, whereby the drive train can be flexibly adapted to the existing conditions of the vehicle.

Alternatively, the transmission gear is designed as a planetary gear with at least one first planetary gear set. A “planetary gear set” is a unit with a sun gear, a ring gear and several of a planet carrier planet gears guided on a circular path around the sun gear, whereby the planet gears mesh with the ring gear and the sun gear.

The first planetary gear set is advantageously designed as a minus planetary gear set, with an overall gear ratio being increased by means of the respective planetary gear set of the planetary gear depending on the respective selected gear on the transmission. By means of the planetary gear arranged in the power flow after the gear, a total gear ratio between 6 and 13.5 can preferably be achieved.

A negative planetary gear set is made up of the elements sun gear, planet carrier and ring gear, with the planet carrier having at least one, but preferably several, planet gears rotatably mounted, each of which meshes or meshes with both the sun gear and the surrounding ring gear. It is also conceivable that the planetary gear is designed as a plus planetary gear set.

A plus planetary set differs from the minus planetary set in that the plus planetary set has first and second or inner and outer planet gears, which are rotatably mounted on the planet carrier. The toothing of the first or inner planet gears meshes with the toothing of the sun gear on the one hand and with the toothing of the second or outer planet gears on the other hand. The teeth of the outer planet gears also mesh with the teeth of the ring gear. This means that when the planet carrier is stationary, the ring gear and the sun gear rotate in the same direction.

When one or more of the P I an etenrad sets are designed as a plus planetary gear set, the connection of the planet carrier and ring gear is swapped and the amount of the stationary gear ratio is increased by 1. This is also possible in reverse if a minus planetary gear set is to be provided instead of a plus planetary gear set.

The planetary gear is connected to the output shaft of the gear in a driving manner, with one of the gear set elements of the first planetary gear set correspondingly forming the input of the planetary gear. A second gear set element of the first planetary gear set forms the output of the planetary gear and a third Gear set elements of the first planetary gear set are supported fixed to the housing. However, the wheelset elements can be connected in any way. According to one exemplary embodiment, the first planetary gear set of the planetary gear has a third sun gear which is non-rotatably connected to the output shaft of the gear, a third ring gear fixed to the housing and a plurality of planetary gears which are rotatably mounted on a third planet carrier. The third sun gear of the transmission gear is therefore connected in a rotationally fixed manner to the second ring gear of the gear. In this case, the transmission gear is preferably arranged coaxially with the stepped planetary gear set of the transmission.

Preferably, the drive train further comprises a differential, which effectively connects the output shaft of the transmission to two output shafts arranged coaxially to an output axle. The differential can be arranged coaxially or parallel to the electric machine. According to one embodiment, the differential is directly, i.e. without intermediate gear ratios or the like, operatively connected to the output shaft of the transmission. In an alternative embodiment, said transmission gear is arranged in the power flow between the output shaft of the transmission or the stepped planetary gear set and the differential. In this sense, a transmission gear is arranged between the output shaft of the transmission and the differential.

According to one embodiment, the differential is designed as a bevel gear differential. Other alternative designs of the differential are also conceivable, for example as a spur gear differential or planetary differential. The drive power coming from the transmission with a first, second or third gear ratio is transmitted from the output shaft of the transmission at least indirectly via the differential to the two output shafts, the differential distributing the drive power, i.e. a speed and a torque, to the output shafts. So that the output shafts are coaxial on the output axle, the differential is also arranged on the output axle and therefore coaxial to the stepped planetary gear set. A differential designed as a bevel gear differential has two wheel-side output elements, in particular a first output gear and a second output gear. The two driven wheels each mesh with a compensating element. The compensation elements are in mounted in a differential carrier so that it can rotate around its own axis. The respective output gear is connected to the respective output shaft in a rotationally fixed manner. The differential is driven via the differential carrier.

Preferably, a differential carrier of the differential is connected in a rotationally fixed manner to the third planet carrier of the first planetary gear set of the transmission gear. It is also conceivable that the output shaft of the transmission is designed to be hollow for the axial passage of one of the two output shafts of the differential. In other words, the respective output shaft can be arranged radially within the first and/or second sun gear of the transmission, wherein one of the two output shafts of the differential can be arranged radially within the output shaft of the transmission.

Alternatively, the differential is designed as an integral differential, having a second planetary gear set and a third planetary gear set operatively connected thereto, each planetary gear set being connected in a driving manner to a respective output shaft, with a first output torque being at least indirectly transferable to the first output shaft by means of the second planetary gear set, and wherein a support torque of the second planetary gear set in the third planetary gear set is convertible in such a way that a second output torque corresponding to the first output torque can be transferred to the second output shaft.

An integral differential is to be understood as meaning a differential with two planetary gear sets, with the second planetary gear set being connected in a driving manner to the output shaft of the transmission or the stepped planetary gear set. The output shaft of the transmission therefore forms the input shaft of the differential or is connected to it in a rotationally fixed manner. The second planetary gear set is connected to the first output shaft for driving purposes. The third planetary gear set is connected to the second output shaft in a driving manner. Furthermore, the third planetary gear set is at least indirectly supported on a stationary housing of the transmission or on the chassis of the motor vehicle, i.e. connected to it in a rotationally fixed manner. By means of the integral differential, the input torque of the input shaft of the differential can be changed and can be divided or transferred to the two output shafts in a defined ratio. Preferably, 50% of the input torque, i.e. half, is transferred to the output shafts. The differential therefore has no component to which the sum of the two output torques is applied. In addition, with identical output speeds of the output shafts, the differential has no teeth rotating in the block or without any rolling movement. In other words, regardless of the output speeds of the output shafts, there is always a relative movement of the components of the respective planetary gear set that mesh with one another. Using the differential, the function of generating the overall translation as well as the differential function are represented. In other words, the integral differential realizes an increase in torque and a division of drive power. Furthermore, there is a weight saving.

Preferably, the integral differential and the output shafts are arranged to be arranged coaxially with the drive axle of the vehicle. The output axle, on which the integral differential and the output shafts lie, thus runs coaxially to the drive axle, in particular coaxially to the axis of rotation of the rotor of the electric machine, coaxially to the input shaft of the transmission and/or coaxially to the output shaft of the transmission.

A first gear set element of the second planetary gear set is connected in a rotationally fixed manner to the output shaft of the transmission, a second gear set element of the second planetary gear set being connected in a rotationally fixed manner with the first output shaft, and a third gear set element of the second planetary gear set being at least indirectly connected in a rotationally fixed manner to a first gear set element of the third Planetary gear set is connected. A second gear set element of the third planetary gear set is connected in a rotationally fixed manner to a stationary component, in particular the stationary housing of the transmission or the chassis of the motor vehicle, with a third gear set element of the third planetary gear set being connected in a rotationally fixed manner to the second output shaft. Preferably, the respective first gear set element of the second or third planetary gear set is to be understood as a sun gear, wherein the respective second gear set element of the second or third planetary gear set is to be understood as a planet carrier, and wherein the respective third gear set element of the second or third planetary gear set is to be understood as a ring gear is.

Preferably, at least the transmission and/or the differential is at least partially or completely arranged spatially within the rotor of the electric machine. By arranging the gearbox and/or the differential radially within the rotor, axial installation space of the drive train can be saved. The drive train is therefore designed to be axially short. For example, the transmission is arranged completely spatially within the rotor of the electric machine. For example, the differential is arranged completely spatially within the rotor of the electrical machine. For example, at least one of the gearshift elements, preferably a plurality of gearshift elements, is arranged within the rotor.

The drive train according to the invention and the transmission according to the invention can be used in purely electrically driven vehicles as well as in hybrid-driven vehicles, which can be driven partly electrically and, if necessary, partly by means of a separate internal combustion engine. Depending on the design and number of driven axles, the vehicle can also include two or more such drive trains or transmissions, whereby one axle, several axles or all axles of the vehicle can be equipped with the respective drive train according to the invention and can therefore be designed to be drivable. Such a vehicle therefore means motor vehicles, in particular cars, commercial vehicles or trucks.

It is understood that features of the solutions described above or in the claims and/or figures can also be combined if necessary in order to be able to implement the advantages and effects mentioned here cumulatively. The invention is described below with reference to figures which show various embodiments of the invention, with the same or similar elements being provided with the same reference numerals. In detail shows:

1 shows a vehicle comprising a drive train according to the invention with a transmission according to the invention according to a first embodiment;

Fig. 2 is a schematic representation of the transmission according to the invention according to Fig. 1;

3 shows a schematic representation of a switching matrix relating to switching states for driving with a transmission according to the invention according to FIG. 2;

4 shows a schematic representation of the transmission according to the invention according to a second embodiment;

5 shows a schematic representation of the transmission according to the invention according to a third embodiment;

6 shows a schematic representation of the transmission according to the invention according to a fourth embodiment;

7 shows a schematic representation of the transmission according to the invention according to a fifth embodiment;

8 shows a schematic representation of the drive train according to the invention with the transmission according to the invention according to FIGS. 1 and 2;

9 shows a schematic representation of the drive train according to the invention with the transmission according to the invention according to a sixth embodiment; 10 shows a schematic representation of the drive train according to the invention with the transmission according to the invention according to a seventh embodiment;

11 shows a schematic representation of the drive train according to the invention with the transmission according to the invention according to an eighth embodiment;

12 shows a schematic representation of the drive train according to the invention with the transmission according to the invention according to a ninth embodiment; and

Fig. 13 is a schematic representation of the drive train according to the invention with the transmission according to the invention according to a tenth embodiment.

1 shows an electrically driven vehicle 1 with a drive train 2 according to the invention according to a first embodiment. The drive train 2 includes an electric machine 11 that generates drive power and introduces it into a transmission 3. The transmission 3 is shown in FIGS. 2 and 8, with an associated switching matrix being shown in FIG. 3. In this case, the transmission 3 transmits the drive power to a coaxially arranged differential 16, which in turn distributes the drive power to a first output shaft 18a and a second output shaft 18b, each of which is connected to a wheel 28 of the vehicle 1 for driving purposes. The differential 16 and the output shafts 18a, 18b lie on an output axle 17, with the output axle 17 here again being arranged coaxially with the drive axle 33, on which the transmission 3 and the electric machine 11 are arranged.

The vehicle 1 can further comprise an energy storage device - not shown here - which supplies the electrical machine 11 with electrical energy and which is supplied with electrical energy by the electrical machine 11 with reverse power flow, i.e. in a generator mode. The energy storage can for example, a battery or the like. In addition, the electrical machine 11 is connected to power electronics - also not shown here.

In Fig. 2, the basic variant of the invention, the transmission 3 from Fig. 1 is shown very schematically. The transmission 3 according to FIG. 2 is rotated in the drive train 2 according to FIG connectable. By means of the electric machine 11, drive power is introduced into the transmission 3 via one of the gearshift elements A, B, C. 2 shows an example of an output shaft 41 of the electric machine 11, which is rotatably connected to the rotor 19 and is operatively connected to the gearshift elements A, B, C. The connection of the rotor 19 to the transmission 3 is symbolized by the vertical arrow on the output shaft 41.

The transmission 3 comprises a stepped planetary gear set 4 with a first ring gear 8a fixed to the housing, a second ring gear 8b, a first sun gear 7a which is connected in a rotationally fixed manner to a first input shaft 29a, a second sun gear 7b which is arranged coaxially and axially adjacent thereto and is connected in a rotationally fixed manner to a second input shaft 29b, which is passed axially through the first sun gear 7a. A first planet carrier 9 is also connected in a rotationally fixed manner to a third input shaft 29c. A plurality of rotatably mounted stepped planetary gears 10 are arranged on the first planet carrier 9. The first gearshift element A is designed to connect the first sun gear 7a or the first input shaft 29a to the rotor 19 of the electric machine 11 in a rotationally fixed manner in a closed state, the second gearshift element B being configured to connect the second sun gear in a closed state 7b or the second input shaft 29b to be connected in a rotationally fixed manner to the rotor 19 of the electric machine 11, and the third gear shifting element C is designed to connect the first planet carrier 9 or the third input shaft 29c to the rotor 19 of the electric machine in a closed state 11 to be connected in a rotationally fixed manner. To drive the output shaft 12 of the transmission 3 in rotation, one of the gearshift elements A, B, C is in the closed state, while the other two gearshift elements A, B, C are open. The drive therefore takes place via one of the two sun gears 7a, 7b or via the first planet carrier 9. The first sun gear 7a is in mesh with a first gear 31a of the respective stepped planetary gear 10 and the second sun gear 7b is in mesh with a second gear 31b of the respective stepped planetary gear 10 in mesh. The two gears 31a, 31b of the respective stepped planetary gear 10 are connected to one another in a rotationally fixed manner. The output takes place via the second ring gear 8b, which meshes with the second gear 31b of the respective stepped planetary gear 10. The first gear 31a also meshes with the first ring gear 8a fixed to a housing 13. The two gears 31a, 31b have different diameters and numbers of teeth, so that, depending on which gear 31a, 31b the drive power is transmitted or which gearshift element A, B, C is closed or open, three different translations are applied to the output of the transmission 3 are transferable. In the present case, the first gear 31a of the respective stepped planetary gear 10 has a smaller diameter than the second gear 31b of the respective stepped planetary gear 10.

When the first gearshift element A is in a closed state or is switched to the closed state and the second and third gearshift elements B, C are in an open state, the first sun gear 7a and the first input shaft 29a are connected to the rotor 19 or respectively the output shaft 41 of the electric machine 11 is connected in a rotationally fixed manner, so that drive power is directed via the first sun gear 7a to the stepped planetary gears 10 and from there via the second ring gear 8b to the output shaft 12 of the transmission 3. When the second gearshift element B is in a closed state or is switched to the closed state and the first and third gearshift elements A, C are in an open state, the second sun gear 7b and the second input shaft 29b are connected to the rotor 19 and respectively the output shaft 41 of the electric machine 11 is connected in a rotationally fixed manner, so that drive power is conducted via the second sun gear 7b to the stepped planetary gears 10 and from there via the second ring gear 8b to the output shaft 12 of the transmission 3. When the third gear shift element C is in a closed state or is switched to the closed state and the first and second If the gear shifting element A, B is in an open state, the first planet carrier 9 or the third input shaft 29c is connected in a rotationally fixed manner to the rotor 19 or to the output shaft 41 of the electric machine 11, so that drive power is transmitted via the first planet carrier 9 to the stepped planetary gears 10 and from there is directed via the second ring gear 8b to the output shaft 12 of the transmission 3. In an open state of the respective gear shift element A, B, C, no torque is transmitted via the respective gear shift element A, B, C, whereas in a closed state of the respective gear shift element A, B, C, a torque is transmitted via the respective gear shift element A, B, C is transmitted. If at least two of the gearshift elements A, B, C are closed, a parking lock function can be implemented.

3 shows a switching matrix for a first gear stage E1, a second gear stage E2 and a third gear stage E3 of the transmission 3. The respective gearshift element A, B, C is closed if “x” is entered and is open if there is no entry. Electric forward travel of the vehicle 1 with three different gear ratios is achieved via the respective gear levels E1, E2, E3. When the first gear shift element A is closed and the second and third gear shift elements B, C are open, the first gear stage E1 is engaged, and thus a first gear ratio is achieved. When the second gear shift element B is closed and the first and third gear shift elements A, C are open, the second gear stage E2 is engaged, and thus a second gear ratio is achieved. When the third gear shift element C is closed and the first and second gear shift elements A, B are open, the third gear stage E3 is engaged, and thus a third gear ratio is achieved. This switching matrix applies to all illustrated embodiments of the invention.

Depending on the design of the gearshift elements A, B, C, a pull and/or push power shift can be implemented. In such a case, the respective gear shifting element A, B, C is designed as a power shifting element, in the present case as a frictionally acting shifting element.

According to Fig. 2 in conjunction with Fig. 8 and in Fig. 6, all gear shifting elements A, B, C are each as positive shifting elements, here as claw shifting elements. formed and, in the closed state, connect the output shaft 41 via the respective input shaft 29a, 29b, 29c with the first sun gear 7a, the second sun gear 7b or the first planet carrier 9. The parts to be connected to one another are ideally synchronized before the positive connection is made. The gear shifting elements A and C are here combined to form a double shifting element 42. The output shaft 41 of the electric machine 11 is therefore arranged axially between the second gear shift element B and the double shift element 42. It is also conceivable to combine the first and second gear shift elements A, B or the second and third gear shift elements B, C to form a double shift element 42. The gear shifting elements A, B, C can be shifted arbitrarily. For example, two separate actuators - not shown here - can be provided, with a first actuator actuating the gear shift element B, which is separate here, and a second actuator actuating the double shift element 42. Alternatively, the gear shift elements A, B, C can be actuated by a shift drum with two, or alternatively three, shift forks. The shift can be done sequentially or individually, so that a shift from the first to the third gear E1, E3, or vice versa, can also take place.

In a second embodiment variant of the transmission 3 according to FIG. 4, the gearshift elements A and B are combined to form a double gearshift element 42, while the third gearshift element C is a separate gearshift element. The output shaft 41 of the electric machine 11 is therefore arranged axially between the third gear shift element C and the double shift element 42. For the rest, please refer to the previous statements.

In a third embodiment variant of the transmission 3 according to FIG. 5, all three gear shift elements A, B, C are combined to form a triple shift element 43, the gear shift elements A, B, C here starting from the output shaft 41 of the electric machine 11 in the axial order: second Gear shift element B, first gear shift element A and third gear shift element C are arranged. The gear shifting elements A, B, C are arranged axially between the output shaft 41 and the stepped planetary gear set 4. The gearshift elements A, B, C are switched sequentially and can be controlled with a common actuator.

In a fourth embodiment variant of the transmission 3 according to FIG. 6, the three gear shift elements A, B, C are also combined to form a triple shift element 43, the difference from the previous embodiment being that the axial order starts from the output shaft 41 of the electric machine 11 here third gearshift element C, second gearshift element B and first gearshift element A. Another difference is that the third input shaft 29c, which is non-rotatably connected to the first planet carrier 9, is designed here as a central shaft within the two sun gears 7a, 7b. The triple switching element 43 can thereby be made axially shorter and more compact. For the rest, please refer to the previous statements.

In a fifth embodiment variant of the transmission 3 according to FIG. 7, the three gear shifting elements A, B, C are designed as non-positive shifting elements or power shifting elements. In the present case, the gear shifting elements A, B, C are multi-plate clutches. This means that synchronization of the rotational speeds of the parts is not necessary. In other words, the gearshift elements A, B, C each implement a pull-load shift between the individual gear stages E1 - E3. The load during shifts between the gear stages E1 - E3 can be supported by one of the gear shift elements A, B, C, while the second of the gear shift elements A, B, C is closed and the third of the gear shift elements A, B, C is opened, or vice versa. This avoids a load drop on the output during switching operations. All gears can be shifted under load. For reasons of space or cost, only individual gear shifting elements can be designed as non-positive shifting elements in order to only carry out specific gear sequences in a load-shifting manner, taking into account the desired pulling or pushing behavior.

8 shows a part of the drive train 2 according to the invention, comprising the transmission 3 according to the invention according to FIG , so that the first Output shaft 18a can be passed axially through the transmission 3 starting from the differential 16, with the second output shaft 18b extending in the opposite direction starting from the differential 16. The exemplary embodiment shown here is a coaxial arrangement of the drive train 2, with the drive axle 33 being arranged coaxially to the output axle 17.

9 to 14 show different embodiment variants of the drive train 2, which was supplemented by the electric machine 11, which can be operatively connected to the transmission 3 via the associated output shaft 41 and to which reference has already been made in FIG. It is made clear that the electric machine 11 is arranged coaxially to the transmission 3 or to the drive axle 33, with the gear shifting elements A, B, C as part of the transmission 3 being accommodated radially within the rotor 19 in order to save axial installation space of the drive train 2.

Fig. 9 shows a sixth exemplary embodiment. In the present case, the transmission 3 is connected in a driving manner via the output shaft 12 to a transmission gear 24, which increases an overall transmission ratio and transmits the drive power to a differential 16 downstream in the power flow, here arranged parallel to the drive axle 33. In this exemplary embodiment, the differential 16 and the output shafts 18a, 18b are arranged on the output axle 17, which is therefore arranged axially parallel to the drive axle 33. The arrangement of the gear shifting elements A, B, C is analogous to Fig. 8 and Fig. 2.

In the present case, the transmission gear 24 is a single-stage spur gear stage 6, consisting of a first gear 39a which is non-rotatably connected to the output shaft 12 and a second gear 39b which is operatively connected to the differential 16. The transmission stage 24 realizes the generation of the overall transmission of the drive train 2 by appropriately designing the gear diameter and number of teeth. By arranging the drive train components axially parallel, axial installation space of the drive train 2 is saved, in particular by the fact that the electric machine 11 together with the transmission 3 and the differential 16 are at least partially arranged next to each other. This also allows the Electric machine 11 can be made slimmer, which in turn has a positive effect on the center distance between the drive and output axles 33, 17.

8 to 12 is designed as a bevel gear differential 5 and connects the gear 3 via the planetary gear 14 to the two output shafts 18a, 18b arranged coaxially to an output axis 17, with the first output shaft 18a moving to the left starting from the differential 16 and the second output shaft 18b are aligned coaxially and oppositely to the right. The bevel gear differential 5 known from the prior art has two wheel-side output elements, which are designed as a first output gear 16b and a second output gear 16c. The driven wheels 16b, 16c each mesh with a compensating element 16d, 16e. The compensating elements 16d, 16e are mounted in a differential carrier 16a so that they can rotate about their own axis. The first output gear 16b is connected to the first output shaft 18a and the second output gear 16c is connected in a rotationally fixed manner to the second output shaft 18b.

8, the differential carrier 16a of the differential 16 is directly connected to the output shaft 12 of the transmission 3 in a rotationally fixed manner. The drive power from the transmission 3 is therefore transmitted directly to the differential 16, in contrast to the other exemplary embodiments. 9 and 10, the differential carrier 16a of the differential 16 is connected to the second gear 39b of the transmission gear 24 in a rotationally fixed manner. 11 and 12, the differential carrier 16a of the differential 16 is connected in a rotationally fixed manner via a first intermediate shaft 32 to a gear set element of the transmission gear 24 designed as a planetary gear 14. Reference will be made to this in more detail in the following comments on FIGS. 11 and 12.

In the examples according to FIGS. 8 and 11 to 13, the differential 16, the output shafts 18a, 18b and, if applicable, the transmission gear 24 are arranged on the drive axle 33. The output axle 17 is thus arranged in relation to the drive axle 33. Only in the examples according to FIGS. 9 and 10 are the output axle 17 and the drive axle 33 aligned axially parallel. The difference between the seventh exemplary embodiment according to FIG . The third gear 39c meshes with the first gear 39a arranged coaxially to the drive axle 33 and the fourth gear 39d meshes with the second gear 39b arranged coaxially to the output axle 17. The two-stage spur gear stage 6 enables a higher range of output ratios to be achieved.

The eighth exemplary embodiment according to FIG. 11 is based on the exemplary embodiment according to FIG. 8, which is why reference is made to the corresponding comments on FIG. 8. The drive train 2 is supplemented by a transmission gear 24 designed as a planetary gear 14, which, together with the differential 16, is arranged coaxially to the gear 3 and to the electric machine 1 1. The output axle 17 is therefore arranged coaxially with the drive axle 33. In the present case, the planetary gear 14 includes a first planetary gear set 15, and two or more planetary gear sets can also be provided. The first planetary gear set 15 is designed as a minus planetary gear set and comprises a third sun gear 20 which is connected in a rotationally fixed manner to the output shaft 12 of the transmission 3, a stationary third ring gear 21 which is connected in a rotationally fixed manner to the housing 13, and a plurality of planetary gears which are rotatably mounted on a second planet carrier 22 23. The third sun gear 20 is connected to the second ring gear 8b of the transmission 3 via the output shaft 12 of the transmission 3 in a drive-effective or rotationally fixed manner, so that the planetary gear 14 is consequently operatively connected to the output shaft 12 on the drive side. The output of the planetary gear 14 takes place via the second planet carrier 22, which is connected to a differential 16 for driving purposes. The second planet carrier 22 is connected to the differential carrier 16a in a rotationally fixed manner via the intermediate shaft 32. Using such a combination of gear 3 and planetary gear 14, for example, total gear ratios between 6 and 13.5 can be achieved. In the present case, the first output shaft 18a is guided axially through the transmission gear 24, the gear 3 and the electric machine 11. The planetary gear 14 is arranged axially between the electric machine 11 and the gear 3 on the one hand and the differential 16 on the other. It is conceivable to use the differential 16 together with the transmission 3 to be arranged spatially within the rotor 19 of the electrical machine 11 in order to save additional axial space.

Fig. 12 differs from Fig. 11 only in the connection of the gear 3 and the differential 16 to the planetary gear 14. In the present case, the third ring gear 21 is connected in a rotationally fixed manner to the output shaft 12 of the gear 3, whereas the third sun gear 20 is arranged fixed to the housing. The output of the planetary gear 14 also takes place here via the second planet carrier 22, which is connected to the differential carrier 16 of the differential 16 via an intermediate shaft 32 guided radially within the third sun gear 20.

13 is also based on the embodiment according to FIG. 8, with the difference that instead of a differential 16 designed as a bevel gear differential, a differential 16 designed as an integral differential 25 is provided, which lies on the output axle 17, which is coaxial with the Drive axle 33 is arranged. The integral differential 25 comprises a second and third planetary gear set 26, 27, the two planetary gear sets 26, 27 being arranged either axially next to one another or radially one above the other, depending on the requirements of the integral differential 25, in particular the translation of the integral differential 25 to be realized. In the present case, the planetary gear sets 26, 27 are arranged radially one above the other or radially nested, whereby axial installation space of the drive train 2 is saved. In other words, the planetary gear sets 26, 27 lie in a common plane perpendicular to the output shafts 18a, 18b or to the output axle 17.

By means of the second planetary gear set 26, a first output torque can be transferred to the first output shaft 18a, which is guided axially through the transmission 3 and the electric machine 11. A supporting torque of the second planetary gear set 26 acting opposite to the first output torque is transferred to the third planetary gear set 27 and is convertible in the third planetary gear set 27 in such a way that a second output torque corresponding to the first output torque can be transferred to the second output shaft 18b. The integral differential 25 is therefore designed as a planetary gear. The integral differential 25 is effectively connected to the transmission 3 via its input shaft, which is also the output shaft 12 of the transmission 3. The output on the integral differential 25 takes place via the two output shafts 18a, 18b. In other words, drive power is divided between two output shafts 18a, 18b by means of the integral differential 25. The second output shaft 18b extends in the opposite direction with respect to the first output shaft 18a. By only arranging the integral differential 25, which increases the torque coming from the transmission 3, at the end of the drive train 2, the components arranged in front of it in the power flow can be made comparatively small and slim, which makes the production of the drive train 2 more cost-effective and reduces the overall weight of the same can be reduced.

The output shaft 12 of the transmission 3 is connected in a rotationally fixed manner to a fourth sun gear 34a of the second planetary gear set 26. The second ring gear 8b of the transmission 3 is thus connected in a rotationally fixed manner to the fourth sun gear 34a. The power transmission from the second planetary gear set 26 to the third planetary gear set 27 takes place via a coupling shaft 35, which is connected, on the one hand, in a rotationally fixed manner to a fourth ring gear 36a of the second planetary gear set 26 and, on the other hand, in a rotationally fixed manner with a fifth sun gear 34b of the third planetary gear set 27. The coupling shaft 35, the fourth ring gear 36a and the fifth sun gear 34b are therefore connected to one another in one piece. The coupling shaft 35 with the fourth ring gear 36a and the fifth sun gear 34b can also be designed as a ring gear, which has external teeth in addition to internal teeth. A plurality of second planet gears 37a are arranged spatially between the fourth sun gear 34a and the fourth ring gear 36a, which in the present case are rotatably arranged on a rotatably mounted third planet carrier 38a. Furthermore, on the same radially extending plane and radially outside the second planetary gear set 26, a plurality of third planetary gears 37b are arranged spatially between the fifth sun gear 34b and a fifth ring gear 36b of the third planetary gear set 27, which in the present case are rotatable on a fourth planetary carrier 38b fixed to the housing are arranged. The first output on the first output shaft 18a takes place via the third planet carrier 38a of the second planetary gear set 26, which is connected to it in a rotationally fixed manner The second output on the second output shaft 18b takes place via the fifth ring gear 36b of the third planetary gear set 27, which is non-rotatably connected to it.

Reference symbol Vehicle Drive train Transmission Stepped planetary gear set Bevel gear differential Spur gear stage a First sun gear b Second sun gear a First ring gear b Second ring gear First planet carrier 0 Stepped planetary gears 1 Electric machine 2 Output shaft of the transmission 3 Housing 4 Planetary gear 5 First planetary gear set 6 Differential 6a Differential cage 6b First output gear of the differential 6c Second output gear of the Differentials 6d Compensating element of the differential 6e Compensating element of the differential 7 Output axle 8a First output shaft 8b Second output shaft 9 Rotor of the electric machine 0 Third sun gear 1 Third ring gear 2 Second planet carrier 3 First planet gear 24 transmission gears

25 Integral Differential

26 Second planetary gear set

27 Third planetary gear set

28 wheel of the vehicle

29a First input wave

29b Second input wave

29c Third input shaft

30 stator of the electrical machine

31 a First gear of the stepped planetary gear

31 b Second gear of the stepped planetary gear

32 First intermediate wave

33 drive axle

34a Fourth sun gear of the integral differential

34b Fifth sun gear of the integral differential

35 coupling shaft of the integral differential

36a Fourth ring gear of the integral differential

36b Fifth ring gear of the integral differential

37a Second planetary gear of the integral differential

37b Third planetary gear of the integral differential

38a Third planet carrier of the integral differential

38b Fourth planet carrier of the integral differential

39a First gear of the transmission gear

39b Second gear of the transmission gear

39c Third gear of the transmission gear

39d Fourth gear of the transmission gear

40 Second intermediate wave

41 Electric machine output shaft

42 double switching element

43 triple switching element

A First gear shift element

B Second gear shift element

C Third gear shift element E1 First gear or first gear stage

E2 Second gear or second gear stage

E3 Third gear or third gear stage

Claims

Patent claims

1 . Transmission (3) for a drive train (2) of an at least partially electrically driven vehicle (1), comprising a stepped planetary gear set (4), a first gearshift element (A), a second gearshift element (B) and a third gearshift element (C), wherein the Stepped planetary gear set (4) has a first sun gear (7a), a second sun gear (7b), a first ring gear (8a), a second ring gear (8b) and a plurality of stepped planetary gears (10) rotatably mounted on a first planet carrier (9), this The first ring gear (8a) is connected in a rotationally fixed manner to a housing (13), the second ring gear (8b) being connected in a rotationally fixed manner to an output shaft (12) of the transmission (3), the first gear shifting element (A) being designed to be in one to connect the first sun gear (7a) to a rotor (19) of an electric machine (11) in a rotationally fixed manner in the closed state, the second gearshift element (B) being designed to connect the second sun gear (7b) to the rotor (19) in a closed state ) of the electric machine (11) to be connected in a rotationally fixed manner, wherein the third gear shifting element (C) is designed to connect the first planet carrier (9) to the rotor (19) of the electric machine (11) in a rotationally fixed manner in a closed state, and where for rotary drive of the output shaft (12) one of the three gear shifting elements (A - C) is in the closed state.

2. Transmission (3) according to claim 1, wherein one of the gear shifting elements (A - C) is designed as a positive shifting element.

3. Transmission (3) according to claim 1 or 2, wherein one of the gear shifting elements (A - C) is designed as a non-positive shifting element.

4. Transmission (3) according to one of the preceding claims, wherein two of the three gear shift elements (A - C) are combined to form a double shift element (42).

5. Transmission (3) according to one of claims 1 to 4, wherein the gear shift elements (A - C) are combined to form a triple shift element (43).

6. Drive train (2) for an at least partially electrically driven vehicle (1), comprising a transmission (3) according to one of the preceding claims and an electric machine (11), the rotor (19) of which is connected to an input shaft (29) of the transmission ( 3) turned connected.

7. Drive train (2) according to claim 6, wherein the output shaft (12) of the transmission (3) forms the input of a step-planet gear set (4) downstream of the transmission gear (24).

8. Drive train (2) according to claim 7, wherein the transmission gear (24) is designed as a planetary gear (14) with at least a first planetary gear set (15).

9. Drive train (2) according to claim 7, wherein the transmission gear (24) is designed as a spur gear stage (6).

10. Drive train (2) according to one of claims 6 to 9, further comprising a differential (16), which drives the output shaft (12) of the transmission (3) with two output shafts (18a, 18b) arranged coaxially to an output axis (17). connects.

11. Drive train (2) according to claim 10, wherein the differential (16) is designed as a bevel gear differential (5).

12. Transmission (3) according to claim 11, wherein the differential (16) is designed as an integral differential (25), having a second planetary gear set (26) and a third planetary gear set (27) operatively connected thereto, each planetary gear set (26, 27) is connected in a drive-effective manner to a respective output shaft (18a, 18b), with a first output torque being at least indirectly transferable to the first output shaft (18a) by means of the second planetary gear set (26), wherein a supporting torque of the second planetary gear set (26) in the third Planetary gear set (27) is convertible in such a way that a second output torque corresponding to the first output torque can be transferred to the second output shaft (18b).

13. Drive train (2) according to claim 12, wherein the integral differential (25) and the output shafts (18a, 18b) are designed to be arranged coaxially to a drive axle (33) of the vehicle (1).

14. Drive train (2) according to one of claims 6 to 13, wherein the transmission (3) and / or the differential (16) is at least partially spatially arranged within the rotor (19) of the electric machine (11).