DE102020216253B4 - Transmission for a motor vehicle - Google Patents

Abstract

Transmission (10; 10') for a motor vehicle (1), comprising an electric machine (23), a first input shaft (14; 14'), a second input shaft (15), an output shaft (16) and a first planetary gear set (36 ), a second planetary gear set (37) and a third planetary gear set (38), the first input shaft (14; 14') being set up to connect the transmission (10; 10') to a prime mover (9) of the motor vehicle (1). connect, wherein the planetary gear sets (36, 37, 38) each comprise a plurality of elements (39 to 47), a first (K1), a second (K2), a third (K3), a fourth (K 4), a fifth (K5) and a sixth switching element (K6) are provided, and wherein a rotor (25) of the electric machine (23) is connected to the second input shaft (15), characterized in that the first element (39) of the first planetary gear set (36) is non-rotatably connected to the second element (44) of the third planetary gear set (38), - that the second element (42) of the ers th planetary gear set (36) is non-rotatably connected to the first element (40) of the second planetary gear set (37), - that the first input shaft (14; 14') is non-rotatably connected to the third element (47) of the third planetary gear set (38), - that the second input shaft (15) is non-rotatably connected to the third element (45) of the first planetary gear set (36), - that the third element (46) of the second planetary gear set (37) and the first element (41) of the third planetary gear set (38) are each permanently fixed, - that the first input shaft (14; 14') is non-rotatably connected to the second element via the first switching element (K1). (42) of the first planetary gear set (36) and the first element (40) of the second planetary gear set (37) and can be connected in a rotationally fixed manner to the second input shaft (15) by means of the second switching element (K2), - that the output shaft (16 ) via the third switching element (K3) non-rotatably with the first element (39) of the first planetary gear set (36) and the second element (44) of the third planetary gear set (38) can be connected by means of the fourth switching element (K4) non-rotatably with the second element (42) of the first planetary gear set (36) and can be connected to the first element (40) of the second planetary gear set (37) and can be connected in a torque-proof manner to the second element (43) of the second planetary gear set (37) via the fifth shifting element (K5). - and that via the sixth switching element (K6) two of the elements (39, 42, 45) of the first planetary gear set (36) can be connected to one another in a torque-proof manner.

Description

The invention relates to a transmission for a motor vehicle, comprising an electric machine, a first input shaft, a second input shaft, an output shaft, and a first planetary gear set, a second planetary gear set and a third planetary gear set, the first input shaft being set up to connect the transmission to a drive motor of the motor vehicle, the planetary gear sets each comprising a plurality of elements, a first, a second, a third, a fourth, a fifth and a sixth switching element being provided, and a rotor of the electric machine being connected to the second input shaft. Furthermore, the invention relates to a motor vehicle drive train, in which an aforementioned transmission is used, and a method for operating a transmission.

In hybrid vehicles, transmissions are known which, in addition to a wheel set, also have one or more electric machines. The transmission is usually designed with multiple gears, d. H. several different transmission ratios can be switched as gears between an input shaft and an output shaft by actuating corresponding switching elements, this preferably being carried out automatically. Depending on the arrangement of the shifting elements, these are either clutches or brakes. In this case, the transmission is used to suitably implement a tractive force available from a drive machine of the motor vehicle with regard to various criteria. The gears of the transmission are usually also used in conjunction with the at least one electric machine to represent purely electric driving. The at least one electric machine can often also be integrated in the transmission in different ways to represent different states.

the DE 10 2018 219 628 A1 discloses a transmission for a motor vehicle, comprising an electric machine, a first input shaft, a second input shaft, an output shaft, three planetary gear sets and at least six shifting elements. By selectively actuating the at least six shifting elements, different gears can be shifted and, in addition, different operating modes can be displayed in interaction with the electric machine.

From the DE 10 2012 212 257 A1 discloses a transmission for a hybrid vehicle which, in addition to a first input shaft and an output shaft, includes three planetary gear sets and an electric machine connected to a second input shaft. Furthermore, in one variant, several switching elements are provided, via which different power flows can be realized from the first input shaft to the output shaft, representing different gears, and different integrations of the electric machine can also be designed. In this case, purely electric driving can also be represented by the sole drive via the electric machine.

It is the object of the present invention to provide an alternative embodiment to the transmission for a motor vehicle known from the prior art, with which different states can be represented in a suitable manner with a compact structure.

This object is achieved based on the preamble of claim 1 in conjunction with its characterizing features. The dependent claims that follow each specify advantageous developments of the invention. A motor vehicle drive train is also the subject of claims 15 to 17. Furthermore, claims 18 and 19 each relate to a method for operating a transmission.

According to the invention, a transmission includes an electric machine, a first input shaft, a second input shaft, an output shaft and a first planetary gear set, a second planetary gear set and a third planetary gear set. The first input shaft is designed to connect the transmission to a drive motor of the motor vehicle. The planetary gear sets comprise a plurality of elements, with each of the planetary gear sets preferably being assigned a first element, a second element and a third element. In addition, a first, a second, a third, a fourth, a fifth and a sixth switching element are provided, through the selective actuation of which, in particular, different power flow guides can be displayed with the switching of different gears. Particularly preferably, exactly five different gears can be formed between the first input shaft and the output shaft from the transmission ratio. Furthermore, a rotor of the electric machine is connected to the second input shaft.

In the context of the invention, a “shaft” is to be understood as meaning a rotatable component of the transmission, via which a power flow can be guided between components, if necessary with simultaneous actuation of a corresponding shifting element. The respective shaft can connect components to one another axially or radially or both axially and radially. The respective shaft can also be present as an intermediate piece, via which a respective component is connected radially, for example. In addition, the respective wave be designed as a one-piece component or be in multiple parts, in that the respective shaft is composed of several shaft parts connected to one another in a torque-proof manner.

In the context of the invention, “axial” means an orientation in the direction of a longitudinal central axis of the transmission, parallel to which the axes of rotation of the planetary gear sets are arranged. “Radial” is then to be understood as meaning an orientation in the diameter direction of a respective rotatable component, in particular a respective shaft.

Within the scope of the invention, the first input shaft, the second input shaft and the output shaft are in particular placed coaxially with one another, with the three planetary gear sets also preferably being arranged coaxially with the input shafts and the output shaft. In particular, the first input shaft is essentially present as a solid shaft, to which the second input shaft and the output shaft are placed radially surrounding as hollow shafts. The second input shaft and the output shaft each overlap axially with a part of the radially inner, first input shaft. Other shafts that connect the individual components of the transmission and in particular the elements of the planetary gear sets to one another or establish a connection when the corresponding shifting element is actuated are preferably each designed as hollow shafts that are arranged radially surrounding the first input shaft.

A coupling with a differential gear arranged axially parallel to the input shafts of the gear is preferably established via the output shaft of the gear. For this purpose, the output shaft particularly preferably carries a spur gear of a first spur gear stage, via which the output shaft is permanently coupled to an intermediate shaft lying parallel to the axis. In addition to a spur gear of the first spur gear stage, a spur gear of a second spur gear stage is also non-rotatably arranged on this intermediate shaft, via which the intermediate shaft is coupled to the differential gear, in that the spur gear of the second spur gear stage arranged on the intermediate shaft meshes with external teeth of a differential carrier of the differential gear. The spur gear on the output shaft is preferably provided axially between the second planetary gear set and the third planetary gear set. This type of arrangement is particularly suitable for use in a motor vehicle with a drive train oriented transversely to the direction of travel of the motor vehicle.

Alternatively, an output via the output shaft of the transmission could in principle also take place at an axial end of the transmission, which is opposite to a connection point of the first input shaft at which a drive movement of the drive machine connected upstream of the transmission can be initiated. As a result, a drive via the first input shaft and an output via the output shaft are placed at opposite axial ends of the transmission. A transmission designed in this way is suitable for use in a motor vehicle with a drive train aligned in the direction of travel of the motor vehicle.

In the axial direction, the planetary gear sets follow, in particular, a connection point at which the first input shaft is or can be coupled to the upstream drive motor of the motor vehicle when the transmission is installed, in the order of first planetary gear set, second planetary gear set and finally third planetary gear set. As already explained above, an output takes place via the output shaft, preferably axially between the second planetary gear set and the third planetary gear set, the output taking place here in particular on a differential gear lying axially parallel.

The invention now includes the technical teaching that the first element of the first planetary gear set is non-rotatably connected to the second element of the third planetary gear set, the second element of the first planetary gear set being non-rotatably connected to the first element of the second planetary gear set. Furthermore, the first input shaft is non-rotatably connected to the third element of the third planetary gear set, while the second input shaft is non-rotatably connected to the third element of the first planetary gear set. In addition, both the third element of the second planetary gear set and the first element of the third planetary gear set are each permanently fixed. The first input shaft can be non-rotatably connected to the second element of the first planetary gear set and the first element of the second planetary gear set via the first switching element and can be non-rotatably connected to the second input shaft by means of the second switching element. Furthermore, the output shaft can be connected in a rotationally fixed manner to the first element of the first planetary gear set and the second element of the third planetary gear set via the third shifting element, connected in a rotationally fixed manner to the second element of the first planetary gear set and the first element of the second planetary gear set by means of the fourth shifting element and connected via the fifth switching element are rotatably connected to the second element of the second planetary gear set. Finally, two of the elements of the first planetary gear set can be connected to one another in a torque-proof manner via the sixth shifting element.

In other words, in the transmission according to the invention, the first element of the first planetary gear set and the second element of the third planetary gear set are permanently connected to one another in a torque-proof manner. Likewise, the second element of the first planetary gear set and the first element of the second planetary gear set are permanently connected to one another in a rotationally fixed manner, so that a rotary movement of the second element of the first planetary gear set always results in a corresponding rotary movement of the first element of the second planetary gear set and vice versa. Furthermore, the first input shaft and the third element of the third planetary gear set are permanently non-rotatably connected to one another, whereas there is a permanent non-rotatable connection between the second input shaft and the third element of the first planetary gear set. In addition, the third element of the second planetary gear set is permanently fixed and thus constantly prevented from rotating. Likewise, the first element of the third planetary gear set is also permanently stationary in that the first element of the third planetary gear set is constantly fixed.

Closing the first shifting element causes the first input shaft and thus also the third element of the third planetary gear set to rotate with the second element of the first planetary gear set and the first element of the second planetary gear set, while actuating the second shifting element creates a torque-proof connection between the first input shaft and with it also results in the third element of the third planetary gear set with the second input shaft. Through the latter, the first input shaft is accordingly also non-rotatably connected to the third element of the first planetary gear set. In the actuated state, the third switching element connects the output shaft in a rotationally fixed manner to the first element of the first planetary gear set and the second element of the third planetary gear set, whereas closing the fourth switching element creates a rotationally fixed connection between the output shaft and the second element of the first planetary gear set and the first element of the second Planetary gear set entails. By closing the fifth switching element, the second element of the second planetary gear set and the output shaft are also connected to one another in a torque-proof manner. Finally, the sixth shifting element, in its actuated state, ensures that the first planetary gearset is locked in that the sixth shifting element connects two of the elements of the first planetary gearset to one another in a rotationally fixed manner when it is actuated.

The switching elements are each in the form of clutches which, when actuated, connect the directly connected components of the transmission to one another in a torque-proof manner, with the speeds of the components to be coupled being synchronized in advance if necessary via the respective switching element.

A respective, permanently non-rotatable connection between components of the transmission has the consequence that rotary movements of these components take place with a fixed speed ratio or a standstill of one component inevitably also causes a standstill of the other component. A permanent non-rotatable connection is preferably realized according to the invention via one or more intermediate shafts, which can also be present as short intermediate pieces if the components are spatially close together. In concrete terms, the components that are permanently connected to one another in a rotationally fixed manner can each be present either as individual components that are rotationally fixedly connected to one another or in one piece. In the second-mentioned case, the respective components and the shaft that may be present are then formed by a common component, this being realized in particular when the respective components in the transmission are spatially close to one another.

In the case of components of the transmission which are connected to one another in a rotationally fixed manner only by actuation of a respective shifting element, a connection is also preferably implemented via one or more intermediate shafts.

The permanent fixing of a component of the transmission is realized in the sense of the invention in particular in that the respective component is permanently connected in a rotationally fixed manner to a rotationally fixed component of the transmission, which is preferably a permanently stationary component, preferably a housing of the transmission, a part of such a housing or a non-rotatably connected component.

The "connection" of the rotor of the electric machine to the second input shaft of the transmission is to be understood within the meaning of the invention as a connection such that there is a constant speed dependency between the rotor of the electric machine and the second input shaft.

Overall, a transmission according to the invention is characterized by a compact design, low component loads, good gearing efficiency and low losses.

According to one embodiment of the invention, the sixth shifting element, when actuated, connects the first element of the first planetary gear set and the second element of the first Planetary gear rotatably together. Accordingly, the blocking of the first planetary gear set is achieved in that the sixth switching element, when actuated, ensures a non-rotatable connection between the first element of the first planetary gear set and the second element of the first planetary gear set.

According to an alternative embodiment of the invention, the sixth shifting element in the actuated state connects the second element of the first planetary gear set and the third element of the first planetary gear set to one another in a torque-proof manner. This also causes the first planetary gearset to be locked when the sixth shifting element is actuated. In contrast to the previous variant, in this case the second element of the first planetary gearset and the third element of the first planetary gearset are connected to one another in a torque-proof manner via the sixth shifting element.

According to one embodiment of the invention, selectively closing the six shifting elements results in five gears, which differ in terms of the transmission ratio, between the first input shaft and the output shaft. A first gear can thus be achieved between the first input shaft and the output shaft by actuating the fifth and sixth shifting element, with the electric machine also being involved in the power flow in the first gear at the same time via the second input shaft.

Furthermore, a second gear results between the first input shaft and the output shaft by locking the first shifting element and the fifth shifting element, while a third gear between the first input shaft and the output shaft is shifted in a first variant by actuating the third shifting element and the fifth shifting element can. Alternatively, the third gear can also be activated in a second variant by engaging the third shifting element and the fourth shifting element, in a third variant by actuating the first shifting element and the third shifting element, in a fourth variant by engaging the second shifting element and the third shifting element, in a fifth variant by actuating the third switching element and the sixth switching element and in a sixth variant by closing the fourth switching element and the sixth switching element.

In addition, a fourth gear can be shifted between the first input shaft and the output shaft by actuating the second shifting element and the fourth shifting element, whereas a fifth gear results between the first input shaft and the output shaft by engaging the first shifting element and the fourth shifting element.

With a suitable choice of fixed gear ratios of the planetary gear sets, a range of ratios suitable for use in the area of a motor vehicle is thereby realized. Shifting between the gears can be realized in which only the state of two shifting elements is to be varied by opening one of the shifting elements involved in the previous gear and closing another shifting element to represent the following gear. This then also means that switching between gears can take place very quickly. In the third gear effective between the first input shaft and the output shaft, however, it is necessary to switch between variants in order to only have to change the state of two shifting elements in the course of a further upshift or downshift to the adjacent gear.

• So kann ein erster Gang zwischen der zweiten Eingangswelle und der Ausgangswelle für ein rein elektrisches Fahren genutzt werden, wobei sich dieser erste Gang durch Schließen des fünften Schaltelements und des sechsten Schaltelements ergibt. Dadurch ist die Elektromaschine über den verblockten, ersten Planetenradsatz und den zweiten Planetenradsatz mit der Ausgangswelle gekoppelt, wobei eine Schaltung und auch eine Übersetzung dieses ersten Ganges dabei denen des ersten, zwischen der ersten Eingangswelle und der Abtriebswelle wirksamen Ganges entspricht. Dabei kann in diesem rein elektrischen Gang bevorzugt der gesamte Geschwindigkeitsbereich abgedeckt werden.

Due to the connection of the electric machine to the second input shaft of the transmission, different states can also be easily implemented:

• A first gear between the second input shaft and the output shaft can thus be used for purely electric driving, with this first gear resulting from the engagement of the fifth shifting element and the sixth shifting element. As a result, the electric machine is coupled to the output shaft via the interlocked, first planetary gear set and the second planetary gear set, with a shift and also a translation of this first gear corresponding to those of the first gear effective between the first input shaft and the output shaft. The entire speed range can preferably be covered in this purely electric gear.

As a further state, charging operation of an electrical energy store can also be implemented by only the first switching element being closed of the first switching element, the second switching element, the third switching element, the fourth switching element, the fifth switching element and the sixth switching element. As a result, the first input shaft is coupled via the third planetary gear set to the first element of the first planetary gear set and, by closing the first switching element, is non-rotatably connected to the second element of the first planetary gear set, while the second input shaft and thus also the electric machine are connected to the third element ment of the first planetary gear set is connected. At the same time, there is no positive connection to the output shaft, so that the transmission is in a neutral position. The second input shaft rotates faster than the first input shaft. Apart from a charging operation, this also allows the upstream drive machine to be started via the electric machine.

Alternatively, charging or starting operation can also be implemented by only closing the second switching element of the first switching element, the second switching element, the third switching element, the fourth switching element, the fifth switching element and the sixth switching element. This results in a direct non-rotatable connection of the first input shaft to the second input shaft, so that the electric machine and a drive machine connected to the first input shaft are also coupled to one another. Again, no frictional connection to the output shaft is established. Due to the direct, non-rotatable connection between the two input shafts, the two input shafts rotate at the same speed.

As a further alternative, charging an electrical energy store or starting the upstream drive machine can also be implemented by only shifting the sixth shifting element of the first shifting element, the second shifting element, the third shifting element, the fourth shifting element, the fifth shifting element and the sixth shifting element into an actuated state is transferred. As a result, the first input shaft is coupled to the second input shaft via the third planetary gear set and the blocked first planetary gear set, with the second input shaft rotating more slowly than the first input shaft. In this case, a direct transition into the first gear effective between the first input shaft and the output shaft can also be carried out by additionally transferring the fifth shifting element to an actuated state.

Furthermore, when shifting between the individual gears, synchronization can be achieved in a targeted manner through the interaction of the electric motor and the upstream drive motor: when changing gears, it is possible to switch between the first gear, which is effective between the first input shaft and the output shaft, and the second gear, which is effective between the first input shaft and effective gear on the output shaft when the fifth shifting element is closed, on the one hand the required output torque of the output shaft is provided and on the other hand the sixth shifting element to be designed for the gear change is made load-free by adjusting the torques of the electric machine and the upstream drive machine accordingly. Once this has happened, the sixth and then no-load shifting element is opened, with the torques of the electric machine and the upstream drive machine then being set in such a way that, on the one hand, the required output torque is still provided at the output shaft, but, on the other hand, the speed of the first input shaft is maintained sinks. If synchronous speeds are then present at the first shifting element to be engaged, then this is closed. As a result, the second gear effective between the first input shaft and the output shaft is then engaged.

Analogously, this is also possible when shifting from the second gear effective between the first input shaft and the output shaft to the first variant of the third gear effective between the first input shaft and the output shaft, in that the fifth shifting element also remains closed here. Torques of the upstream drive machine and the electric machine are again set in such a way that the respectively required drive torque is provided at the output shaft and, moreover, the first shifting element to be designed is load-free. Once this has been achieved, the first switching element is opened and, as a result, the setting of the torques of the upstream drive machine and the electric machine is changed. This is done in such a way that on the one hand the required drive torque is provided and on the other hand there is a change in the speed of the first input shaft in the range of a synchronous speed of the third shift element that is now to be closed. If the third shifting element then has the same speed, it is actuated, whereby the first variant of the third gear is shifted.

For a further upshift, it is then necessary to switch between the first variant of the third gear and the second variant of the third gear, with an upshift then taking place from the second variant of the third gear into the fourth gear, which is effective between the first input shaft and the output shaft can. The fourth shifting element now remains closed in order to provide the required drive torque by setting the torques of the upstream drive motor and the electric machine on the one hand and to get the third shifting element to be designed for the upshift load-free on the other. When there is no load, the third switching element is then opened, with the torques of the upstream drive machine and the electric machine then being set in such a way that the required drive torque is still produced at the output shaft and a Drop in the speed of the first input shaft takes place. If synchronous speeds are then reached at the second shifting element to be engaged, the second shifting element is engaged, as a result of which the fourth gear effective between the first input shaft and the output shaft is engaged.

Finally, it is also possible to change from the fourth gear, effective between the first input shaft and the output shaft, to the fifth gear, effective between the first input shaft and the output shaft, with the fourth shifting element engaged, for which purpose the second shifting element, which is now to be opened, is free of load Adjustment of the moments of the upstream drive machine and the electric machine is caused. If the second switching element is load-free, it is opened and the torques of the upstream drive machine and the electric machine are then adjusted to achieve synchronous speeds on the first switching element that is now to be actuated. The output torque required in each case is always provided at the output shaft, with this being closed when synchronous speeds are reached at the first switching element, so that the fifth gear effective between the first input shaft and the output shaft is switched.

The above-described load shifts with the aid of the electric machine are preferably implemented when the shifting elements are each designed as positive-locking shifting elements and in this case in particular as unsynchronized claw shifting elements. Downshifts take place in the same way as the upshifts described above, only with the reverse process. Overrun shifts are also possible, in that the electric machine supports a corresponding braking torque on the first planetary gear set.

As a further state, a starting mode for forward travel when driven via the first input shaft and thus the upstream drive machine can also be implemented. For this purpose, in a first variant of the first switching element, the second switching element, the third switching element, the fourth switching element, the fifth switching element and the sixth switching element, only the fifth switching element is closed. As a result, the prime mover can be driven via the first input shaft by means of the third planetary gear set and via the first element of the first planetary gear set, with the electric machine being supported at the same time via the second input shaft on the third element of the first planetary gear set, while an output is generated via the second element of the first planetary gear set by means of the second planetary gear set takes place on the output shaft. From this state, the upstream drive machine can be shifted in the first gear effective between the first input shaft and the output shaft, in the second gear effective between the first input shaft and the output shaft and also in the first variant of the third gear, between the first input shaft and the Output shaft effective gear are operated, since the fifth switching element is also closed in each of these gears.

In addition, in a second variant, a starting mode for forward travel when driven via the first input shaft by means of the upstream drive machine can be implemented, for which purpose only that of the first shifting element, the second shifting element, the third shifting element, the fourth shifting element, the fifth shifting element and the sixth shifting element fourth switching element is to be closed. As a result, the upstream drive machine is connected to the first element of the first planetary gear set via the first input shaft and by means of the third planetary gear set and can drive via the first element, while the electric machine can carry out support on the third element of the first planetary gear set via the second input shaft. An output to the output shaft then takes place through a direct non-rotatable connection of the second element of the first planetary gear set to the output shaft. From this variant of a starting mode, the upstream drive machine can then be operated in the second or sixth variant of the third gear effective between the first input shaft and the output shaft, in the fourth gear effective between the first input shaft and the output shaft, or in the fifth gear, between the first input shaft and the output shaft effective gear are operated because the fourth switching element is also closed in each of these gears.

The variants described above for designing a starting mode can also be used within the scope of the invention for power-split operation, since in the respective state there is a superimposition of rotary movements of the upstream drive machine and the electric machine on the first planetary gear set, so that one Drive movement of the upstream drive machine can be combined in a suitable manner with a drive movement of the electric machine or braking via the electric machine. In this way, battery-neutral operation can also be implemented.

According to a further embodiment of the invention, the first input shaft can be coupled via a seventh switching element to a connection shaft, which is used to connect the transmission to the engine of the motor vehicle. Accordingly, the upstream drive machine can also be completely decoupled from the transmission via the seventh switching element, so that purely electric operation can be implemented without any problems. The connecting shaft is preferably coaxial with the first input shaft and is more preferably permanently coupled via a transmission step to an axis-parallel drive shaft which is permanently connected to the upstream drive machine—possibly via an intermediate torsional vibration damper. The transmission stage is in particular designed as a traction mechanism and in this case more preferably as a chain drive, with the transmission stage alternatively being able to be designed as a spur gear drive.

As an alternative to this, however, it is also conceivable for the first input shaft to be permanently coupled to an intermediate shaft lying parallel to the axis, which can be connected in a rotationally fixed manner to the connection shaft via the seventh shifting element. The connecting shaft is then in particular coaxial with the intermediate shaft and is connected to the upstream drive machine when the transmission is installed—possibly via an intermediate torsional vibration damper. The coupling between the first input shaft and the intermediate shaft is preferably implemented here via a traction drive, which is in particular a chain drive. Alternatively, an embodiment as a spur gear drive would also be conceivable here.

The seventh shifting element is preferably designed as a non-positive shifting element and more preferably as a multi-plate shifting element, with a design as a friction clutch also being possible as an alternative.

According to an embodiment of the invention, the rotor of the electric machine is rigidly connected to the second input shaft. As an alternative to this, one possible embodiment of the invention is for the rotor to be connected to the second input shaft via at least one transmission step. In both variants mentioned above, the electric machine can be arranged coaxially to the planetary gear sets, wherein in the case of the second variant, an axially offset arrangement of the electric machine to the planetary gear sets is also conceivable. In the coaxial arrangement, the rotor of the electric machine can either be rigid, i.e. directly non-rotatable, connected to the second input shaft or coupled to it via one or more intermediate transmission stages, with the latter enabling a more favorable design of the electric machine with higher speeds and lower torque . The at least one transmission stage can be designed as a spur gear stage and/or as a planetary stage. In the case of a coaxial arrangement of the electric machine, the first planetary gear set is also preferably arranged axially at the level of the electric machine and radially on the inside of it, so that the overall axial length of the transmission can be shortened.

If, on the other hand, the electric machine is provided with an offset axis in relation to the planetary gear sets, then a coupling takes place via one or more intermediate transmission stages and/or a traction drive. The one or more transmission stages can also be implemented individually either as a spur gear stage or as a planetary stage. A traction drive can be either a belt drive or a chain drive.

In a further development of the invention, one or more switching elements are each implemented as a positive-locking switching element. In this case, the respective shifting element is preferably designed either as a claw shifting element or as a blocking synchronization. Positive shifting elements have the advantage over non-positive shifting elements that lower drag losses occur in the open state, so that better efficiency of the transmission can be achieved. In particular, in the transmission according to the invention, the first shifting element, the second shifting element, the third shifting element, the fourth shifting element, the fifth shifting element and also the sixth shifting element are implemented as positive-locking shifting elements, so that the lowest possible drag losses can be achieved. In principle, however, one of these shifting elements or several of these shifting elements could also be designed as non-positive shifting elements, for example as lamellar shifting elements.

The planetary gear sets can, insofar as it allows the elements to be connected, each be present as a minus planetary gear set within the scope of the invention, with the first element of the respective planetary gear set being a sun gear, the second element of the respective planetary gear set being a planet carrier and the third element of the respective planetary gear set is a ring gear. In this case, at least one, but preferably several planetary gears are rotatably mounted in the planet carrier, each of which meshes with the sun gear and the surrounding ring gear.

Alternatively, one or more planetary gearsets could be present as a plus planetary gearset, provided the connection of the respective elements allows it, with the first element of the respective planetary gearset being a sun gear and the second element of the respective planetary gearset being a ring gear and the third element of the respective planetary gear set is a planetary carrier. In a plus planetary gear set, the elements sun gear, ring gear and planetary carrier are also present, with the latter guiding at least one pair of planetary gears in a rotatable manner, in which one planetary gear meshes with the internal sun gear and the other planetary gear meshes with the surrounding ring gear, as well as the planetary gears comb with each other.

Where it is possible to connect the individual elements, a minus planetary gearset can be converted into a plus planetary gearset, in which case the ring gear and planetary carrier connection must be swapped over compared to the negative planetary gearset design, and a gear ratio increased by one. Conversely, a plus planetary gear set could also be replaced by a minus planetary gear set, provided that the connection of the transmission elements allows this. In this case, in comparison to the plus planetary gear set, the ring gear and planet carrier connection would also have to be swapped with one another, and a gear ratio would have to be reduced by one. In the context of the invention, however, the three planetary gear sets are preferably each designed as a minus planetary gear set.

According to a further embodiment of the invention, the first switching element and the second switching element are combined to form a switching device, to which an actuating element is assigned. The first switching element on the one hand and the second switching element on the other hand can be actuated via the actuating element from a neutral position. This has the advantage that the number of actuating elements and thus also the production costs can be reduced by combining them.

As an alternative or in addition to the aforementioned variant, the fourth switching element and the fifth switching element are combined to form a switching device, to which an actuating element is assigned. This actuating element can be used to actuate the fourth shifting element on the one hand and the fifth shifting element on the other hand from a neutral position. As a result, the production costs can be reduced by combining the two switching elements into one switching device, in that one actuating device can be used for both switching elements.

As an alternative or in addition to the two aforementioned variants, the third switching element and the sixth switching element are combined to form a switching device, to which an actuating element is assigned. This actuating element can be used to actuate the third shifting element on the one hand and the sixth shifting element on the other hand from a neutral position. This also makes it possible to reduce the production costs, since the two switching elements can thus be actuated via a common actuating device.

However, all three of the aforementioned shifting devices are particularly preferably implemented, so that the six shifting elements of the transmission can be actuated via three actuating elements. As a result, a particularly low production cost can be achieved.

Within the scope of the invention, the transmission can be preceded by a starting element, for example a hydrodynamic torque converter or a friction clutch. This starting element can then also be part of the transmission and is used to design a starting process by enabling a slip speed between the engine, which is designed in particular as an internal combustion engine, and the first input shaft of the transmission. In this case, one of the shifting elements of the transmission or the seventh shifting element that may be present can also be designed as such a starting element, in that it is present as a friction shifting element. In addition, a freewheel to the transmission housing or to another shaft can in principle be arranged on each shaft of the transmission.

The transmission according to the invention is in particular part of a motor vehicle drive train for a hybrid or electric vehicle and is then arranged between a drive motor of the motor vehicle designed as an internal combustion engine or as an electric machine and other components of the drive train following in the direction of power flow to the drive wheels of the motor vehicle. In this case, the first input shaft of the transmission is either permanently coupled in a rotationally fixed manner to a crankshaft of the internal combustion engine or the rotor shaft of the electric machine, or can be connected to it via an intermediate starting element or the seventh shifting element that may be provided, with a torsional vibration damper between an internal combustion engine and the transmission can be provided. On the output side, the transmission within the motor vehicle drive train is then preferably provided with a differential gear coupled to a drive axle of the motor vehicle, although here there can also be a connection to a longitudinal differential, via which distribution to a plurality of driven axles of the motor vehicle takes place. The differential gear or the longitudinal differential can be arranged with the gear in a common housing. A torsional vibration damper that may be present can also be integrated into this housing.

According to one embodiment of the invention, a further drive axle of the hybrid vehicle can be driven via a further electric machine in the motor vehicle drive train. In this case, the drive train of the motor vehicle is designed in such a way that one drive axle, preferably a front axle of the motor vehicle, can be driven via the drive engine by means of the intermediate transmission according to the invention, while a further drive axle, preferably a rear axle, can be driven independently of this via a further electric machine is drivable. In this case, this additional electric machine is coupled in particular to a differential gear of the drive axle, in which case an additional gear can be provided between the additional electric machine and the differential gear.

For the purposes of the invention, the fact that two components of the transmission are “connected” or “coupled” or “are connected to one another” means a permanent coupling of these components so that they cannot rotate independently of one another. In this respect, no switching element is provided between these components, which can be elements of the planetary gear sets and/or shafts and/or a non-rotatable component of the transmission, but the corresponding components are coupled to one another with a constant speed dependency.

If, on the other hand, a switching element is provided between two components, these components are not permanently coupled to one another, but coupling is only effected by actuating the switching element lying between them. An actuation of the switching element in the sense of the invention means that the relevant switching element is transferred to a closed state and as a result the components directly connected to it are adjusted to one another in terms of their rotational movements, if necessary. If the shifting element in question is designed as a positive shifting element, the components connected directly to one another in a rotationally fixed manner will run at the same speed, while in the case of a non-positive shifting element, there may be speed differences between the components even after it has been actuated. Within the scope of the invention, this desired or also undesired state is nevertheless referred to as a non-rotatable connection of the respective components via the switching element.

The invention is not limited to the specified combination of features of the main claim or the claims dependent thereon. In addition, there are possibilities of combining individual features with one another, even if they emerge from the claims, the following description of preferred embodiments of the invention or directly from the drawings. Reference of the claims to the drawings by the use of reference signs is not intended to limit the scope of the claims.

• 1 eine schematische Ansicht eines Kraftfahrzeugs mit einem Kraftfahrzeugantriebsstrang entsprechend einer bevorzugten Ausführungsform der Erfindung;
• 2 eine schematische Ansicht eines Teils des Kraftfahrzeugantriebsstranges aus 1 im Bereich eines Getriebes, welches entsprechend einer ersten Ausführungsform der Erfindung gestaltet ist;
• 3 eine schematische Darstellung eines Getriebes gemäß einer zweiten Ausgestaltungsmöglichkeit der Erfindung,
• 4 ein beispielhaftes Schaltschema der Getriebe aus den 2 und 3; und
• 5 eine tabellarische Darstellung unterschiedlicher Zustände des Kraftfahrzeugantriebsstranges aus 1 mit einem Getriebe nach 2 oder 3.

Advantageous embodiments of the invention, which are explained below, are shown in the drawings. It shows:

• 1 a schematic view of a motor vehicle with a motor vehicle drive train according to a preferred embodiment of the invention;
• 2 Figure 12 is a schematic view of a portion of the automotive powertrain 1 in the field of a transmission designed according to a first embodiment of the invention;
• 3 a schematic representation of a transmission according to a second embodiment of the invention,
• 4 an exemplary shift pattern of the transmission from the 2 and 3 ; and
• 5 a tabular representation of different states of the motor vehicle drive train 1 with a gearbox after 2 or 3 .

1 shows a schematic view of a motor vehicle 1, which is a hybrid vehicle. The motor vehicle 1 has a first drive axle 2 and a second drive axle 3, of which the first drive axle 2 is a steerable, drivable front axle of the motor vehicle 1, while the second drive axle 3 is designed as a non-steerable, drivable rear axle . The two drive axles 2 and 3 are each part of a motor vehicle drive train 4 of the motor vehicle 1, it being possible for drive wheels 5 and 6 of the first drive axle 2 and drive wheels 7 and 8 of the second drive axle 3 to be driven independently within the motor vehicle drive train 4.

The drive wheels 5 and 6 of the first drive axle 2 can be driven by a drive machine 9 in the form of an internal combustion engine via an intermediate gearbox 10, whereas on the second drive axle 3 it is possible to drive the drive wheels 7 and 8 via an electric machine 11 by means of an intermediate gearbox 12 is. The interposed gear 12 is preferably a differential gear, via which a drive power of the electric machine 11 can be distributed to the two drive wheels 7 and 8 of the second drive axle 3 .

Out of 2 1 is a schematic representation of part of the motor vehicle drive train 4 1 in the area of the transmission 10, the latter being designed in accordance with a first embodiment of the invention. The transmission 10 includes a connection shaft 13, a first input shaft 14, a second input shaft 15 and an output shaft 16, which are arranged coaxially to one another. The connecting shaft 13 and the first input shaft 14 are each designed as solid shafts and can be connected to one another in a torque-proof manner via an intermediate shifting element K0, which is present as a non-positive shifting element in the form of a multi-plate clutch. In contrast, the second input shaft 15 and the output shaft 16 are each designed as hollow shafts, which are each placed radially surrounding the first input shaft 14 and each axially overlap with a partial section of the first input shaft 14 .

The connecting shaft 13 is coupled at one axial end of the transmission 10 via an intermediate transmission stage 17 to an axis-parallel drive shaft 18 which is coupled within the motor vehicle drive train 4 via an intermediate torsional vibration damper 19 to the upstream drive motor 9 . In the present case, the drive shaft 18 and the torsional vibration damper 19 can also be integrated into a transmission housing of the transmission 10 . In the present case, the transmission stage 17 is designed as a traction mechanism, this traction mechanism being a chain drive 20 . A first chain wheel 21 is arranged on the connection shaft 13 in a rotationally fixed manner, which is coupled to a second chain wheel 22 via a drive chain, this second chain wheel 22 being placed in a rotationally fixed manner on the drive shaft 18 .

As in 2 can be seen, the transmission 10 also includes an electric machine 23 which is composed of a stator 24 and a rotor 25 . The stator 24 of the electric machine 23 is permanently fixed to a non-rotatable component 26 of the transmission 10, this non-rotatable component 26 preferably being the transmission housing of the transmission 10, a part of this transmission housing or a non-rotatable connected component. The electric machine 23 is arranged coaxially to the second input shaft 15, the rotor 25 of the electric machine 23 being connected in a rotationally fixed manner to the second input shaft 15 by a rigid connection being formed between the rotor 25 and the second input shaft 15. The electric machine 23 can be operated on the one hand as a generator and on the other hand as an electric motor.

The output shaft 16 is coupled via a spur gear stage 27 to an axis-parallel intermediate shaft 28 , the spur gear stage 27 being composed of a spur gear 29 and a spur gear 30 . The spur gear 29 is arranged in a rotationally fixed manner on the output shaft 16 and is permanently in meshing engagement with the spur gear 30 which is placed in a rotationally fixed manner on the intermediate shaft 28 . The intermediate shaft 28 also carries a spur gear 31 of a spur gear stage 32, with which the intermediate shaft 28 is coupled to a differential carrier 33 of a differential gear 34 lying parallel to the axis. The differential carrier 33 is connected in a rotationally fixed manner to a spur gear 35 of the spur gear stage 32 , the spur gear 35 being permanently in mesh with the spur gear 31 placed on the intermediate shaft 28 . Via the differential gear 34, a drive power within the motor vehicle drive train 4 in 1 are distributed to the two drive wheels 5 and 6 of the drive axle 2. The two spur gear stages 27 and 32, the intermediate shaft 28 and also the differential gear 34 are preferably also part of the gear 10 and are integrated into the gear housing of the gear 10. In this respect, the differential carrier 33 of the differential gear 34 forms an output side of the gear 10.

The transmission 10 also includes three planetary gear sets 36, 37 and 38, each of the planetary gear sets 36, 37 and 38 having a first element 39 or 40 or 41, a second element 42 or 43 or 44 and a third element 45 or 46 or 47. The respective first element 39 or 40 or 41 is formed by a respective sun gear of the respective planetary gear set 36 or 37 or 38, while the respective second element 42 or 43 or 44 of the respective planetary gear set 36 or 37 or 38 is present as a planet carrier and the respective third element 45 or 46 or 47 of the respective planetary gear set 36 or 37 or 38 is present as a ring gear.

In the present case, the first planetary gear set 36, the second planetary gear set 37 and the third planetary gear set 38 are each a negative planet Netensatz before, the respective planetary carrier leads rotatably mounted at least one planetary gear, which is in mesh with both the respective radially inner sun gear, as well as the respective radially surrounding ring gear. However, a plurality of planet gears are particularly preferably provided in the first planetary gear set 36, in the second planetary gear set 37 and also in the third planetary gear set 38.

If the connection permits, one or more of the planetary gear sets 36, 37 and 38 could each also be designed as a positive planetary gear set, in which case the respective second element 42 or 43 or 44 then the respective ring gear and the respective third element 45 or 46 or 47 formed by the respective planet carrier and also a respective gear ratio must be increased by one. In a plus planetary gear set, the planetary carrier then guides at least one pair of planetary gears in a rotatably mounted manner, of whose planetary gears a planetary gear meshes with the radially inner sun gear and a planetary gear meshes with the radially surrounding ring gear, and the planetary gears mesh with one another.

As in 2 As can be seen, in addition to the shifting element K0, the transmission 10 also includes six further shifting elements K1, K2, K3, K4, K5 and K6, which are each designed as positive-locking shifting elements and are preferably present as unsynchronized dog-type shifting elements. In addition, the switching elements K1, K2, K3, K4, K5 and K6 are each designed as clutches.

In the present case, the first element 39 of the first planetary gear set 36 is connected in a rotationally fixed manner to the second element 44 of the third planetary gear set 38 via a shaft 48, while the second element 42 of the first planetary gear set 36 is permanently rotationally fixed via a shaft 49 to the first element 40 of the second planetary gear set and 30 is connected. Furthermore, the third element 45 of the first planetary gear set 36 is permanently connected to the second input shaft 15 in a torque-proof manner, whereas the first input shaft 14 is permanently connected in a torque-proof manner to the third element 47 of the third planetary gear set 38 . In addition, both the third element 46 of the second planetary gear set 37 and the first element 41 of the third planetary gear set 38 are each constantly fixed to the non-rotatable component 26 of the transmission 10 .

As also in 2 As can be seen, the first input shaft 14 can be connected in a rotationally fixed manner to the shaft 49 via the shifting element K1, thus also to the second element 42 of the first planetary gearset 36 and the first element 40 of the second planetary gearset 37. In addition, the first input shaft 14 can be non-rotatably connected to the second input shaft 15 by means of the shifting element K2, which subsequently also results in a non-rotatable connection between the third element 45 of the first planetary gear set 36 and the third element 47 of the third planetary gear set 38 . Closing the shifting element K3 results in a non-rotatable connection of the output shaft 16 with the shaft 48 and thus also with the first element 39 of the first planetary gearset 36 and the second element 44 of the third planetary gearset 38. If the shifting element K4 is brought into a closed state, then the output shaft 14 is non-rotatably connected to the shaft 49 so that the output shaft 14 is subsequently non-rotatably connected to the second member 42 of the first planetary gear set 36 and the first member 40 of the second planetary gear set 37 .

By closing the shifting element K5, the second element 43 of the second planetary gear set 37 is non-rotatably connected to the output shaft 16, in that the shifting element K5 produces a non-rotatable connection between the output shaft 16 and a shaft 50, which is constantly non-rotatably connected to the second element 43 of the second planetary gear set 37 connected is. Finally, the shifting element K6 causes a non-rotatable connection between the shaft 48 and the shaft 49 in the closed state, which thus also results in a non-rotatable connection of the first element 39 of the first planetary gear set 36 and the second element 42 of the first planetary gear set 36 . The latter means blocking of the first planetary gear set 36.

In the present case, the shafts 48, 49 and 50 are also placed coaxially with the first input shaft 14, the second input shaft and the output shaft 16, with the shafts 48, 49 and 50 being designed as hollow shafts, each radially surrounding the first input shaft 14 are arranged and each overlap axially with a part of the first input shaft 14 .

The planetary gear sets 36, 37 and 38 are also coaxial with the input shafts 14 and 15 and the output shaft 16, being arranged axially following the shifting element K0 in the order of the first planetary gear set 36, the second planetary gear set 37 and the third planetary gear set 38. The electric machine 23 is arranged axially at the level of the first planetary gear set 36 , the first planetary gear set 36 being provided radially on the inside of the electric machine 23 .

How also from 2 As can be seen, the shifting element K1 and the shifting element K2 are arranged axially between the first planetary gear set 36 and the shifting element K0, with the shifting element K2 being placed axially between the first planetary gear set 36 and the shifting element K1. The shifting element K1 and the shifting element K2 are located axially directly next to each other and radially at the same height and are combined to form a shifting device 51, in that a common actuating element is assigned to the shifting element K1 and the shifting element K2, via which, on the one hand, the shifting element K1 and on the other hand the switching element K2 can be actuated.

The shifting element K4 and the shifting element K5 are provided axially between the spur gear stage 27 and the second planetary gear set 37, with the shifting element K4 being placed axially between the spur gear 29 of the spur gear stage 27 and the shifting element K5. The shifting element K4 and the shifting element K5 are placed axially directly next to each other and radially at the same height and have a common actuating element, via which the shifting element K4 on the one hand and the shifting element K5 on the other hand can be actuated from a neutral position. In this respect, the switching element K4 and the switching element K5 are combined to form a switching device 52 .

Likewise, the switching element K3 and the switching element K6 are combined to form a switching device 53 by being arranged axially directly next to one another and radially at the same height. In the case of the switching device 53, both the switching element K3 and the switching element K6 can be transferred from a neutral position into an actuated state via a common actuating element. The shifting element K3 and the shifting element K6 are provided axially between the second planetary gearset 37 and the third planetary gearset 38, with the shifting elements K3 and K6 being located axially between the third planetary gearset 38 and the spur gear 29 of the spur gear stage 27. The switching element K3 is here arranged axially adjacent to the spur gear 29 which is placed on the output shaft 16 in a rotationally fixed manner.

The third element 46 of the second planetary gear set 37 is connected to the non-rotatable component 26 essentially axially at the level of the second planetary gear set 37, while the first element 41 of the third planetary gear set 38 is connected axially between the third planetary gear set 38 and the shifting device 53 with the non-rotatable component 26 is connected. The consequence of this is that the second element 44 of the third planetary gear set 38 is connected to the shaft 48 and the third element 47 of the third planetary gear set 38 is connected to the first input shaft 14 axially from an axial end of the transmission 10 in a torque-proof manner , which is opposite to the axial end of the transmission 10 at which the coupling of the connecting shaft 13 via the transmission step 17 is formed. A radial section of shaft 48, via which the connection to second element 44 is established, is provided axially between third planetary gear set 38 and a radial section of first input shaft 14, via which the rotationally fixed connection of first input shaft 14 to the third element 47 is formed.

Furthermore goes out 3 a schematic view of part of a transmission 10 'according to a second embodiment of the invention, which is also in the motor vehicle drive train 4 in 1 can be applied. This configuration possibility largely corresponds to the previous variant 2 , with the difference that a connection of the elements 41, 44 and 47 of the third planetary gear set 38 has been made differently. The first element 41 is connected to the non-rotatable component 26 from an axial end of the transmission 10', while a shaft 48', via which the first element 39 of the first planetary gear set 36 and the second element 44 of the third planetary gear set 38 are non-rotatably connected to one another are, for the non-rotatable connection to the second element 44 is guided axially between the switching device 53 and the third planetary gear set 38 radially outward. In this case, the shaft 48 ′, encompassing the third planetary gear set 38 , is then brought up to the second element 44 from the axial end of the transmission 10 ′. For a non-rotatable connection of the third element 47 of the third planetary gear set 38 with a first input shaft 14', the first input shaft 14' is guided radially outwards axially between the third planetary gear set 38 and the section of the shaft 48' that is guided radially outwards, with the non-rotatable connection to the third element 47 is made. Otherwise, the design option corresponds to 3 according to the variant 2 , so that reference is made to what has been described here.

In 4 FIG. 12 is an example shift pattern for the transmissions 10 and 10' of FIGS 2 and 3 tabulated. As can be seen, a total of five gears with different transmission ratios can be realized between the first input shaft 14 or 14' and the output shaft 16, with an X in the columns of the shift pattern identifying which of the shifting elements K1, K2 , K3, K4, K5 and K6 in which of the aisles is closed.

As in 4 As can be seen, a first gear V1 is shifted between the first input shaft 14 or 14' and the output shaft 16 by actuating the shifting elements K5 and K6. Furthermore, a second gear V2 results between the first input shaft 14 or 14′ and the output shaft 16 by closing the shifting elements K1 and K5. A third gear can be shown between the first input shaft 14 or 14' in a first variant V3.1 by actuating the shifting elements K3 and K5, this third gear also being obtained in a second variant V3.2 by closing the shifting elements K3 and K4, in a third variant V3.3 by actuating the switching elements K1 and K3, in a fourth variant V3.4 by closing the switching elements K2 and K3, in a fifth variant V3.5 by actuating the switching elements K3 and K6 and in a sixth Variant V3.6 results from closing the switching elements K4 and K6.

In addition, there is a fourth gear V4 between the first input shaft 14 or 14' and the output shaft 16 by actuating the shifting elements K2 and K4, while a fifth gear V5 between the first input shaft 14 or 14' and the output shaft 16 by closing the Switching elements K1 and K4 is shown. The gears V1 to V5 can be connected to the output shaft due to the coupling of the first input shaft 14 or 14', which in turn can be connected via the shifting element KO to the connecting shaft 13 and accordingly via the transmission stage 17 and the drive shaft 18 to the upstream drive machine 9 16 are each used for a drive via the upstream drive machine 9.

Furthermore, there is another gear E1 between the second input shaft 15 and the output shaft 16, which is shifted by closing the shifting elements K5 and K6. By coupling the second input shaft 15 to the output shaft 16 in gear E1, the electric machine 23 can be integrated accordingly, so that the drive axle 2 can be driven via the electric machine 23 in gear E1. From the representation, this gear E1 corresponds to the gear V1 between the first input shaft 14 or 14′ and the output shaft 16, so that when the upstream drive machine 9 is integrated in the gear V1, the electric machine 23 is also always integrated by additionally closing the shifting element K0 .

In 5 are different states I to XVI of the motor vehicle drive train 4 from 1 when using the transmission 10 off 2 or the transmission 10' 3 tabulated. A total of sixteen different states I to XVI can be represented. The columns then indicate which of the gears is shifted with regard to the electric machine 23 and the drive machine 9, with 0 meaning that there is no or no independent connection of the electric machine 23 or the drive machine 9 to the output shaft 16 and thus also to the differential gear 34 of the drive axle 2 is produced.

In a first state I, charging or starting operation can be implemented in that of the switching elements K1 to K6 only the switching element K1 is closed and the switching element K0 is actuated. As a result, the first input shaft 14 or 14' and thus also the drive machine 9 are coupled via the third planetary gear set 38 to the first element 39 of the first planetary gear set 36 and, by closing the first shifting element K1, non-rotatably to the second element 42 of the first planetary gear set 36 connected, while the second input shaft 15 and thus also the electric machine 23 rotatably connected to the third element 45 of the first planetary gear set 36 is connected. At the same time, there is no positive connection to the output shaft 16, so that the transmission 10 or 10' is in a neutral position. In the first state I, the second input shaft 15 rotates faster than the first input shaft 14 or 14'. When the electric machine 23 is operated as a generator, an electrical energy store can be charged, while when the electric machine 23 is operated as an electric motor, the drive machine 9 can be started via the electric machine 23 .

In a second state II, an energy store can also be charged when the electric machine 23 is operated as a generator and the upstream drive machine 9 can be started when the electric machine 23 is operated by an electric motor, for which purpose only the switching element K2 has to be closed and the switching element K0 has to be actuated. Because this results in a direct non-rotatable connection of the first input shaft 14 or 14' to the second input shaft 15, so that the electric machine 23 and the drive machine 9 connected to the first input shaft 14 or 14' via the shifting element KO are also coupled to one another . Again, no frictional connection to the output shaft 15 is established. Due to the direct, non-rotatable connection of the two input shafts 14 or 14' and 15, the two input shafts 14 or 14' and 15 rotate at the same speed.

Furthermore, in a third state III, charging or starting operation can be implemented by Switching element K0 is closed and switching element K6 is actuated. As a result, the first input shaft 14 or 14' and thus also the drive machine 9 connected via the shifting element K0 are coupled to the second input shaft 15 via the third planetary gear set 38 and the locked, first planetary gear set 36, with the second input shaft 15 rotating more slowly than the first input shaft 14 or 14'. In this state III, a direct transition to gear V1 can also be carried out by additionally switching the shifting element K5 to an actuated state. When the electric machine 23 is operated as a generator, an energy store can be charged, while when it is operated as an electric motor, the drive machine 9 connected via the switching element K0 can be started.

When the electric machine 23 is operating as a generator, states I to III can also be used to generate electricity, which is used to drive the drive axle 3 in the motor vehicle drive train 4 by means of the electric machine 12 .

Furthermore, in a fourth state IV, the drive axle 2 of the motor vehicle drive train 4 can be driven purely electrically, for which purpose the switching elements K5 and K6 are to be closed while the switching element K0 is open, so that the drive motor 9 is decoupled. As a result, the gear E1 is shifted between the second input shaft 15 and the output shaft 16 in the transmission 10 or 10′ and the electric machine 23 is thus integrated, so that the drive axle 2 can be driven in its electric motor operation.

Furthermore, in a state V, a starting mode for forward travel when driven by the upstream drive machine 9 can be implemented, for which purpose only the switching element K5 has to be actuated in addition to the switching element K0. As a result, the prime mover 9 drives the first element 39 of the first planetary gear set 36 via the first input shaft 14 or 14' by means of the third planetary gear set 38, while the electric machine 23 is supported via the second input shaft 15 on the third element 45 of the first planetary gear set 36 and an output can take place on the output shaft 16 via the second element 42 of the first planetary gear set 36 by means of the second planetary gear set 37 . From this state, the upstream drive machine 9 can be started in the gear V1, in the gear V2 and in the gear V3.1, since the shifting element K5 is also closed in each of these gears.

In a state VI, a starting mode for forward travel when driven by the engine 9 can also be displayed in the motor vehicle drive train 4, for which purpose only the switching element K4 has to be closed in addition to the switching element K0. As a result, the upstream drive machine 9 is connected via the first input shaft 14 or 14' and by means of the third planetary gear set 38 to the first element 39 of the first planetary gear set 36 and can drive via the first element 39, while the electric machine 23 via the second input shaft 15 Supporting the third element 45 of the first planetary gear set 36 can make. An output on the output shaft 16 then takes place through a direct non-rotatable connection of the second element 42 of the first planetary gear set 36 to the output shaft 16. From this state VI, the upstream drive machine 9 can be in the gear V3.2, the gear V3.6, the gear V4 or the gear V5 are operated because the switching element K4 is also closed in each of these gears.

States V and VI can also be used for power-split operation, since in the respective state V or VI there is a superimposition of rotational movements of the upstream drive machine 9 and the electric machine 23 on the first planetary gear set 36, so that a drive movement of the upstream drive machine 9 can be superimposed in a suitable manner with a drive movement of the electric machine 23. In this way, battery-neutral operation can also be implemented.

In the states VII to XVI, the drive axle 2 is then driven via the upstream drive machine 9, with one of the gears V1, V2, V3.1, V3.2, V3.3, V3.4, V3.5 , V3.6, V4 or V5 switched, like this too 4 has been described, and additionally the switching element K0 is closed. In this case, a forward drive of the motor vehicle 1 takes place. Thus, in state VII in gear V1, in state VIII in gear V2, in state IX in gear V3. 1, in the state X in the gear V3.2, in the state XI in the gear V3.3, in the state XII in the gear V3.4, in the state XIII in the gear V3.5, in the state XIV in gear V3.6, in state XV in gear V4 and in state XVI in gear V5. As a special feature, in state VII, a drive can also take place at the same time via the electric machine 23, which is also integrated, since the gear V1 corresponds to the gear E1 in terms of the shifting logic.

• So kann beim Wechsel von Zustand VII in Zustand VIII und damit auch zwischen dem Gang V1 und dem Gang V2 einerseits das geforderte Abtriebsmoment an der Ausgangswelle 16 bereitgestellt und andererseits das für den Gangwechsel auszulegende Schaltelement K6 lastfrei gemacht werden, indem Momente der Elektromaschine 23 und der vorgeschalteten Antriebsmaschine 9 entsprechend eingestellt werden. Ist dies geschehen, so wird das Schaltelement K6 geöffnet, wobei darauf folgend die Momente der Elektromaschine 23 und der vorgeschalteten Antriebsmaschine 9 so eingestellt werden, dass zwar einerseits nach wie vor das jeweils geforderte Abtriebsmoment an der Ausgangswelle 16 bereitgestellt wird, andererseits aber die Drehzahl der ersten Eingangswelle 14 bzw. 14' absinkt. Liegen dann synchrone Drehzahlen am zu betätigenden Schaltelement K1 vor, so wird dieses geschlossen.

Although the switching elements K1, K2, K3, K4, K5 and K6 are each designed as form-fitting switching elements, one on top of the other the following switching between the states VII to XVI take place under load:

• Thus, when changing from state VII to state VIII and thus also between gear V1 and gear V2, on the one hand the required output torque can be provided at the output shaft 16 and on the other hand the shifting element K6 to be designed for the gear change can be made load-free by torques from the electric machine 23 and the upstream drive machine 9 are set accordingly. Once this has happened, the switching element K6 is opened, with the torques of the electric machine 23 and the upstream drive machine 9 then being set in such a way that, on the one hand, the required output torque is still provided at the output shaft 16, but on the other hand the speed of the first input shaft 14 or 14' drops. If synchronous speeds are then present at the switching element K1 to be actuated, then this is closed.

As a result, gear V2 is then engaged and the transition to state VIII is thus completed.

In an analogous manner, this is also possible when shifting from gear V2 to gear V3.1 and thus when changing between state VIII and state IX, in that the shifting element K5 also remains closed here. Torques of the upstream drive machine 9 and the electric machine 23 are again set in such a way that a required drive torque is provided at the output shaft and the shifting element K1 to be designed is also load-free. If this is achieved, the first switching element K1 is opened and as a result a setting of the torques of the upstream drive machine 9 and the electric machine 23 is changed. This is done in such a way that on the one hand the required drive torque is provided and on the other hand there is a change in the speed of the first input shaft 14 or 14′ in the range of a synchronous speed of the shifting element K3 that is now to be engaged. If there is then an equal speed at the shifting element K3, then this is actuated, as a result of which the gear V3.1 is shifted and the transition to state IX is thus completed.

In order to be able to shift up further under load, before a transition to state XV, one has to switch from state IX and thus gear V3.1 to state X and thus gear V3.2. An upshift to gear V4 can then take place from gear V3.2, with the shifting element K4 now remaining closed in order to provide the required drive torque on the one hand and the required drive torque on the other hand by adjusting the torques of the upstream drive machine 9 and the electric machine 23 to get the upshift to be interpreted switching element K3 load-free. When there is no load, the shifting element K3 is then opened, with the torques of the upstream drive machine 9 and the electric machine 23 then being adjusted in such a way that the required drive torque is still produced at the output shaft 16 and the speed of the first input shaft 14 or 14 decreases ' takes place. If synchronous speeds are then reached at the shifting element K2 to be engaged, the second shifting element K2 is engaged, as a result of which the gear V4 is engaged.

Finally, for a change from state XV to state XVI and thus from gear V4 to gear V5, first a load-free condition is brought about on the shifting element K2 to be opened for this purpose by adjusting the torques of the upstream drive machine 9 and the electric machine 23 . If the switching element K2 is load-free, it is opened and the torques of the upstream drive machine 9 and the electric machine 23 are then adjusted to achieve synchronous speeds on the switching element K1 to be actuated below. The output torque required in each case is always provided, with this being closed when synchronous speeds are reached at the shifting element K1, so that the gear V5 is shifted and the state XVI is reached.

Analogously to the above-described upshifts between the gears V1 to V5, downshifts can also be implemented by reversing the sequences accordingly. In this case, overrun shifts are also possible in that the electric machine 23 in each case supports a corresponding torque on the first planetary gear set 36 in a braking manner.

By means of the configurations according to the invention, a transmission with a compact design and a high level of efficiency can be implemented.

Reference List

1

motor vehicle

2

drive axle

3

drive axle

4

automotive powertrain

5

drive wheel

6

drive wheel

7

drive wheel

8th

drive wheel

9

prime mover

10

transmission

10'

transmission

11

electric machine

12

transmission

13

connecting shaft

14

first input wave

14'

first input wave

15

second input shaft

16

output shaft

17

translation stage

18

drive shaft

19

torsional vibration damper

20

chain drive

21

Sprocket

22

Sprocket

23

electric machine

24

stator

25

rotor

26

non-rotatable component

27

spur gear stage

28

intermediate shaft

29

spur gear

30

spur gear

31

spur gear

32

spur gear stage

33

differential cage

34

differential gear

35

spur gear

36

First planetary gear set

37

Second planetary gear set

38

Third planetary gear set

39

first element first planetary gear set

40

first element second planetary gear set

41

first element third planetary gear set

42

second element first planetary gear set

43

second element second planetary gear set

44

second element third planetary gear set

45

third element first planetary gear set

46

third element second planetary gear set

47

third element third planetary gear set

48

Wave

48'

Wave

49

Wave

50

Wave

51

switching device

52

switching device

53

switching device

K0

switching element

K1

switching element

K2

switching element

K3

switching element

K4

switching element

K5

switching element

K6

switching element

I to XVI

conditions

Claims (19)

Transmission (10; 10') for a motor vehicle (1), comprising an electric machine (23), a first input shaft (14; 14'), a second input shaft (15), an output shaft (16) and a first planetary gear set (36 ), a second planetary gear set (37) and a third planetary gear set (38), the first input shaft (14; 14') being set up to connect the transmission (10; 10') to a prime mover (9) of the motor vehicle (1). connect, wherein the planetary gear sets (36, 37, 38) each comprise a plurality of elements (39 to 47), a first (K1), a second (K2), a third (K3), a fourth (K 4), a fifth (K5) and a sixth switching element (K6) are provided, and wherein a rotor (25) of the electric machine (23) is connected to the second input shaft (15), characterized in that - that the first element (39) of the first planetary gear set (36) is non-rotatably connected to the second element (44) of the third planetary gear set (38), - that the second element (42) of the first planetary gear set (36) is connected in a rotationally fixed manner to the first element (40) of the second planetary gear set (37), - that the first input shaft (14; 14') is non-rotatably connected to the third element (47) of the third planetary gear set (38), - that the second input shaft (15) is non-rotatably connected to the third element (45) of the first planetary gear set (36) is connected, - that the third element (46) of the second planetary gear set (37) and the first element (41) of the third planetary gear set (38) are each permanently fixed, - that the first input shaft (14; 14') via the first switching element (K1) can be connected in a rotationally fixed manner to the second element (42) of the first planetary gear set (36) and the first element (40) of the second planetary gear set (37) and can be connected in a rotationally fixed manner to the second input shaft (15) by means of the second switching element (K2). - that the output shaft (16) can be connected in a torque-proof manner to the first element (39) of the first planetary gearset (36) and the second element (44) of the third planetary gearset (38) via the third shifting element (K3), by means of the fourth shifting element ts (K4) can be connected in a rotationally fixed manner to the second element (42) of the first planetary gear set (36) and to the first element (40) of the second planetary gear set (37), and via the fifth switching element (K5) in a rotationally fixed manner to the second element (43 ) of the second planetary gear set (37) can be connected, - and that two of the elements (39, 42, 45) of the first planetary gear set (36) can be connected to one another in a torque-proof manner via the sixth shifting element (K6). Gear (10; 10 ') after claim 1 , characterized in that the sixth switching element (K6) in the actuated state, the first element (39) of the first planetary gear set (36) and the second element (42) of the first planetary gear set (36) non-rotatably together. Gear (10; 10 ') after claim 1 , characterized in that the sixth switching element (K6) in the actuated state, the second element (42) of the first planetary gear set (36) and the third element (45) of the first planetary gear set (36) non-rotatably together. Transmission (10; 10 ') according to one of Claims 1 until 3 , characterized in that - a first gear (V1) between the first input shaft (14; 14') and the output shaft (16) by actuating the fifth (K5) and the sixth shifting element (K6), - a second gear (V2 ) between the first input shaft (14; 14') and the output shaft (16) by closing the first (K1) and fifth shifting element (K5), - a third gear between the first input shaft (14; 14') and the output shaft ( 16) in a first variant (V3.1) by actuating the third (K3) and the fifth switching element (K5), in a second variant (V3.2) by closing the third (K3) and the fourth switching element (K4), in a third variant (V3.3) by actuating the first (K1) and the third switching element (K3), in a fourth variant (V3.4) by closing the second (K2) and the third switching element (K3), in one fifth variant (V3.5) by actuating the third (K3) and the sixth switching element (K6) and in a sixth variant e (V3.6) by closing the fourth (K4) and the sixth shift element (K6), - a fourth gear (V4) between the first input shaft (14; 14') and the output shaft (16) by actuating the second (K2) and the fourth shifting element (K4), - and a fifth gear (V5) between the first input shaft (14; 14') and the output shaft (16) by closing of the first (K1) and the fourth switching element (K4). Transmission (10; 10') according to one of the preceding claims, characterized in that a first gear (E1) between the second input shaft (15) and the output shaft (16) by engaging the fifth (K5) and sixth shifting element (K6 ) results. Transmission (10; 10') according to one of the preceding claims, characterized in that the first input shaft (14; 14') can be coupled via a seventh shifting element (K0) to a connecting shaft (13) which is used to connect the transmission (10; 10') with the engine (9) of the motor vehicle (1). Transmission (10; 10') according to one of the preceding claims, characterized in that the rotor (25) of the electric machine (23) is rigidly connected to the second input shaft (15) or is connected to the second input shaft via at least one transmission stage. Transmission (10; 10') according to one of the preceding claims, characterized in that the electric machine (23) is arranged coaxially to the first planetary gear set (36), the first planetary gear set (36) being located axially at the level of and radially on the inside of the electric machine (23 ) is placed. Transmission (10; 10') according to one of the preceding claims, characterized in that one or more of the shifting elements (K1, K2, K3, K4, K5, K6) are each implemented as a positive-locking shifting element, in particular as a claw shifting element. Transmission (10; 10') according to one of the preceding claims, characterized in that that the respective planetary gear set (36, 37, 38) is present as a negative planetary gear set, with the respective first element (39, 40, 41) of the respective planetary gear set (36, 37, 38) being a respective sun gear, with the respective second element (42, 43, 44) of the respective planetary gear set (36, 37, 38) around a respective planet carrier and in the respective third element (45, 46, 47) of the respective planetary gear set (36, 37, 38) around a respective ring gear acts. Transmission (10; 10') according to one of the preceding claims, characterized in that the respective planetary gear set (36, 37, 38) is present as a positive planetary set, the respective first element (39, 40, 41) of the respective planetary gear set (36, 37, 38) around a respective sun gear, with the respective second element (42, 43, 44) of the respective planetary gear set (36, 37, 38) around a respective ring gear and with the respective third element (45, 46, 47) of the respective planetary gear set (36, 37, 38) is a respective planet carrier. Transmission (10; 10') according to one of the preceding claims, characterized in that the first shifting element (K1) and the second shifting element (K2) are combined to form a shifting device (51), which is assigned an actuating element, with the actuating element being a neutral position out on the one hand the first switching element (K1) and on the other hand the second switching element (K2) can be actuated. Transmission (10; 10') according to one of the preceding claims, characterized in that the fourth shifting element (K4) and the fifth shifting element (K5) are combined to form a shifting device (52), which is assigned an actuating element, with the actuating element being a neutral position out on the one hand the fourth switching element (K4) and on the other hand the fifth switching element (K5) can be actuated. Transmission (10; 10') according to one of the preceding claims, characterized in that the third shifting element (K3) and the sixth shifting element (K6) are combined to form a shifting device (53), which is assigned an actuating element, with the actuating element being a neutral position out on the one hand the third switching element (K3) and on the other hand the sixth switching element (K6) can be actuated. Motor vehicle drive train (4) for a hybrid or electric vehicle, comprising a transmission (10; 10 ') according to one or more of Claims 1 until 14 . Motor vehicle drive train (4) after claim 15 , characterized in that the transmission (10; 10') is provided between a prime mover (9) and a drive axle (2) of the hybrid vehicle. Motor vehicle drive train (4) after Claim 16 , characterized in that a further drive axle (3) of the hybrid vehicle can be driven via a further electric machine (11). Method for operating a transmission (10; 10 ') according to one of Claims 1 until 14 , characterized in that to represent a charging operation or a starting operation of the first switching element (K1), the second switching element (K2), the third switching element (K3), the fourth switching element (K4), the fifth switching element (K5) and the sixth Switching element (K6) only the first switching element (K1) or the second switching element (K2) or the sixth switching element (K6) is closed. Method for operating a transmission (10; 10 ') according to one of Claims 1 until 14 , characterized in that to represent a starting mode for forward travel when driven via the first input shaft (14; 14') by the first shifting element (K1), the second shifting element (K2), the third shifting element (K3), the fourth shifting element (K4 ), the fifth switching element (K5) and the sixth switching element (K6), only the fifth switching element (K5) or only the fourth switching element (K4) is closed.

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