DE102022204849A1 - Motor vehicle transmissions, especially hybrid or electric vehicle transmissions - Google Patents

Abstract

The invention relates to a motor vehicle transmission (6), comprising a drive shaft (9), an output shaft (10) and a first planetary gear set (P1), a second planetary gear set (P2) and a third planetary gear set (P3), the drive shaft (9) for a coupling with an electric machine (5) is provided. In addition, at least functionally, a first switching element (A), a second switching element (B), a third switching element (C) and a fourth switching element (D) are provided. The invention further relates to a drive unit (4), a drive axle (3) and a hybrid or electric vehicle.

Description

The invention relates to a motor vehicle transmission, in particular a hybrid or electric vehicle transmission, comprising a drive shaft, which is provided for a drive-effective connection to a drive machine, an output shaft and a first planetary gear set, a second planetary gear set and a third planetary gear set, each of which has a first element, each have a second element and a third element in the form of a sun gear, a planetary web and a ring gear, with at least functionally a first switching element, a second switching element, a third switching element and a fourth switching element being provided, and wherein the first element of the first planetary gear set is non-rotatably connected to the drive shaft and the second element of the third planetary gear set is non-rotatably connected to the output shaft. The invention further relates to a drive unit with an aforementioned motor vehicle transmission, a drive axle, a hybrid or electric vehicle and a method for operating a motor vehicle transmission.

In the case of hybrid and electric vehicles, a motor vehicle transmission is partly provided in a respective drive train between a respective electric machine and drive wheels of the respective motor vehicle in order to translate a drive movement of the electric machine, in particular into a slow one, to the drive wheels. In addition to single-speed gearboxes, commercial vehicles also use gearboxes in which two or more gears can be shifted.

From the WO 2015/082166 A1 shows a drive unit for an electric vehicle, this drive unit being composed of an electric machine and a motor vehicle transmission. In addition to three planetary gear sets, the motor vehicle transmission also includes several switching elements, through the selective actuation of which a drive shaft and an output shaft of the motor vehicle transmission can be coupled to shift different gears. The drive shaft is connected to a rotor of the electric machine in a rotationally fixed manner. The planetary gear sets are each composed of a first element, a second element and a third element, one of which is designed as a sun gear, one as a planetary web and one as a ring gear. One of the elements of the planetary gear sets is connected in a rotationally fixed manner to the drive shaft and thus also to the rotor of the electric machine, while another element is constantly connected in a rotationally fixed manner to the output shaft.

Based on the prior art described above, it is now the object of the present invention to create a motor vehicle transmission by means of which different gears and a parking lock function can be displayed with a compact design. In particular, this motor vehicle transmission should be suitable for use in a drive unit of a hybrid or electric vehicle.

This task is solved based on the preamble of claim 1 in conjunction with its characterizing features. The following dependent claims each reflect advantageous developments of the invention. A drive unit which has a motor vehicle transmission according to the invention is also the subject of claims 10 and 11. Furthermore, claims 12 and 13 relate to a drive axle with such a drive unit. In addition, claim 14 relates to a hybrid or electric vehicle. Finally, claims 15 and 16 each relate to a method for operating a motor vehicle transmission.

According to the invention, a motor vehicle transmission comprises a drive shaft, which is provided for a drive-effective connection to a drive machine, an output shaft and a first planetary gear set, a second planetary gear set and a third planetary gear set, each of which has a first element, a second element and a third Have elements in the form of a sun gear, a planetary web and a ring gear. Furthermore, at least functionally, a first switching element, a second switching element, a third switching element and a fourth switching element are provided. Furthermore, the first element of the first planetary gear set is non-rotatably connected to the drive shaft, while the second element of the third planetary gear set is non-rotatably connected to the output shaft.

For the purposes of the invention, a “shaft” is to be understood as meaning a rotatable component of the transmission, via which power flow can be guided between components, whereby an associated, at least functionally provided switching element may have to be actuated for this purpose. 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 only a radial connection is achieved.

For the purposes of the invention, “axial” means an orientation in the direction of a longitudinal central axis of the transmission, parallel to which axes of rotation of rotatable components of the transmission, in particular the shafts of the transmission and the elements elements of the planetary gear sets are arranged. “Radial” is then understood to mean an orientation in the diameter direction of a respective component of the transmission.

In the motor vehicle transmission according to the invention, the drive shaft is intended to establish a driving connection to a drive machine. For this purpose, the drive shaft is in particular equipped with a connection point at which a coupling of the drive shaft to the drive machine can be formed. This coupling between the drive machine and the drive shaft is such that, in the installed state of the motor vehicle transmission, a fixed speed ratio always prevails between a speed of the drive shaft of the motor vehicle transmission and a speed of the drive machine. In the context of the invention, at least one further transmission stage, such as a spur gear stage and/or a planetary stage, can be provided between the drive shaft and the drive machine, via which a pre-translation of a rotary movement of the drive machine onto the drive shaft can be represented. Particularly preferably, however, there is a rotationally fixed connection of the drive machine to the drive shaft of the motor vehicle transmission according to the invention, so that the drive machine and the drive shaft run at the same speed during operation.

The motor vehicle transmission is in particular a hybrid or electric vehicle transmission, which is intended to be connected to a drive machine in the form of an electric machine on the drive shaft. A rotor of this electric machine can, as described above, be coupled to the drive shaft of the transmission via at least one intermediate gear ratio. Particularly preferably, a rotor of the electric machine is connected to the drive shaft in a rotationally fixed manner when the motor vehicle transmission according to the invention is installed.

In the motor vehicle transmission according to the invention, the output shaft is intended in particular to produce an output-side coupling of the motor vehicle transmission to components which, in the installed state of the motor vehicle transmission, follow the motor vehicle transmission in the direction of power flow to the drive wheels of the respective motor vehicle.

In the motor vehicle transmission according to the invention, the drive shaft and the output shaft are arranged in particular coaxially with one another, with the planetary gear sets also preferably being placed coaxially with the drive shaft and the output shaft. This makes it possible to achieve a particularly compact design of the motor vehicle transmission in the radial direction.

The planetary gear sets are each composed of a first element, a second element and a third element, with the elements of the individual planetary gear set being formed by a sun gear, a planetary web and a ring gear. Particularly preferably, the individual planetary gear set is in the form of a minus planetary gear set, in which the respective planetary web guides at least one planetary gear in a rotatable manner, with the at least one planetary gear meshing with both the respective sun gear and the respective ring gear. If the respective planetary gear set is designed as a minus planetary gear set, the first element of the respective planetary gear set is then in particular the respective sun gear, the second element of the respective planetary gear set is the respective planetary web and the third element of the respective planetary gear set is the respective ring gear .

Alternatively, in principle one or more of the planetary gear sets could each be designed as a plus planetary gear set. In this case, at least one pair of planetary gears is rotatably mounted in the respective planetary web, of which a planetary gear is in mesh with the respective sun gear and a planetary gear is in mesh with the respective ring gear. In addition, the planetary gears of the at least one pair of planetary gears mesh with one another. In contrast to an embodiment as a minus planetary gear set, the first element of the respective planetary gear set is then preferably the sun gear, the second element of the respective planetary gear set is the ring gear and the third element of the respective planetary gear set is the planetary web. In comparison to a version as a negative planetary gear set, the stationary gear ratio of the respective planetary gear set must also be increased by one. As already described above, for the purposes of the invention, all planetary gear sets are preferably designed as negative planetary gear sets. More preferably, exactly three planetary gear sets are provided in the electric vehicle transmission according to the invention.

The motor vehicle transmission according to the invention has, at least functionally, a first switching element, a second switching element, a third switching element and a fourth switching element, different gears being able to be represented between the drive shaft and the output shaft, in particular by selective actuation of the first switching element, the second switching element and the third switching element . Particularly preferred In terms of function, exactly four switching elements are provided in the motor vehicle transmission according to the invention, with exactly three different gears being able to be switched between the drive shaft and the output shaft via these switching elements. In principle, within the scope of the invention, in addition to the first switching element, the second switching element, the third switching element and the fourth switching element, one or more further switching elements could be provided, at least functionally.

The fact that a respective switching element is provided “at least functionally” means in the sense of the invention that at least the respective function of the respective switching element is represented in the motor vehicle transmission according to the invention. The switching elements can actually be physically present as individual switching elements or their function is represented by another component, such as a switching device. A component that represents the function can then combine the function of two or more switching elements in one device.

The invention now includes the technical teaching that the third element of the third planetary gear set is fixed. Furthermore, the third element of the second planetary gear set is connected in a rotationally fixed manner to the second element of the third planetary gear set and the output shaft. The second element of the first planetary gear set and the first element of the second planetary gear set are connected to one another in a rotationally fixed manner, while the second element of the second planetary gear set and the first element of the third planetary gear set are connected to one another in a rotationally fixed manner. The first switching element is intended to fix the third element of the first planetary gear set, while the second switching element is intended to rotationally connect the third element of the first planetary gear set to the second element of the second planetary gear set and the first element of the third planetary gear set. Furthermore, the third switching element is intended to connect two of the elements of the first planetary gear set to one another in a rotationally fixed manner, whereas the fourth switching element is intended to connect two of the elements of the second planetary gear set to one another in a rotationally fixed manner.

Accordingly, in the electric vehicle transmission according to the invention, the first element of the first planetary gear set is constantly connected to the drive shaft in a rotationally fixed manner, as a result of which the drive shaft and the first element of the first planetary gear set always run at the same speed. Furthermore, the output shaft, the second element of the third planetary gear set and the third element of the second planetary gear set are permanently connected to one another in a rotationally fixed manner, as a result of which the second element of the third planetary gear set, the third element of the second planetary gear set and the output shaft always have the same speed. The third element of the third planetary gear set is constantly fixed, so that the third element of the third planetary gear set is constantly prevented from rotating. Furthermore, the second element of the first planetary gear set and the first element of the second planetary gear set are constantly connected to one another in a rotationally fixed manner and always rotate together, while the second element of the second planetary gear set and the first element of the third planetary gear set always have the same speed, in that the second element of the second planetary gear set and the first element of the third planetary gear set are permanently connected to one another in a rotationally fixed manner.

In the sense of the invention, the individual, permanently rotationally fixed connection is preferably implemented via an intermediate shaft, which can be in one or more parts. In addition, within the scope of the invention, a respective embodiment is also possible in which the respective shaft is designed in one piece with one or both components that are connected to it in a rotationally fixed manner, the latter being realized in particular when the components of the transmission that are permanently connected to one another are spatially close to one another are arranged.

Closing the first switching element, which is at least functionally provided, results in the third element of the first planetary gear set becoming fixed, so that it is subsequently prevented from rotating. If, on the other hand, the at least functionally provided second switching element is transferred to a closed state, the third element of the first planetary gear set is connected in a rotationally fixed manner to the second element of the second planetary gear set and the first element of the third planetary gear set, which allows the third element of the first planetary gear set to rotate together , the second element of the second planetary gear set and the first element of the third planetary gear set. When closed, the third switching element, which is provided at least functionally, ensures a rotationally fixed connection between two elements of the first planetary gear set, which results in the first planetary gear set becoming blocked and thus its block circulation. If the fourth switching element, which is at least functionally provided, is actuated, two of the elements of the second planetary gear set are connected to one another in a rotationally fixed manner. This results in the second planetary gear set becoming blocked and thus its block rotation.

The permanently fixed state of the third element of the third planetary gear set as well as the fixing of the third element of the first planetary gear set via the first switching element takes place in particular in that the respective element is connected in a rotationally fixed manner to a permanently fixed component or is connected to it in a rotationally fixed manner. The permanently fixed component is preferably a gear housing of the motor vehicle transmission, a part of the gear housing or a component connected to it in a rotationally fixed manner. The third element of the third planetary gear set can also be designed in one piece with the permanently fixed component.

In an actuated state of the third switching element, which is at least functionally present, two of the three elements of the first planetary gear set are connected to one another in a rotationally fixed manner, so that the first planetary gear set is blocked. Within the scope of the invention, in the actuated state of the at least functionally present third switching element, the first element and the second element of the first planetary gear set, the first element and the third element of the first planetary gear set or the second element and the third element of the first planetary gear set can be rotationally fixed be connected to each other.

If the fourth switching element, which is at least functionally present, is transferred to an actuated state, two of the three elements of the second planetary gear set are connected to one another in a rotationally fixed manner, as a result of which the second planetary gear set is blocked. Specifically, within the scope of the invention, in the actuated state of the at least functional fourth switching element, the first element and the second element of the second planetary gear set, the first element and the third element of the second planetary gear set or the second element and the third element of the second planetary gear set can be rotationally fixed be connected to each other.

The embodiment of a motor vehicle transmission according to the invention has the advantage that several different gears can be switched between the drive shaft and the output shaft via the switching elements, which means that in the installed state of the motor vehicle transmission, a translation of a drive movement of an upstream drive machine with different gear ratios is also possible. In particular, in combination of the motor vehicle transmission with a drive machine in the form of an electric machine, a drive unit suitable for use in an electric vehicle can thereby be created. This is possible due to the construction of the motor vehicle transmission according to the invention with a compact structure, so that a direct arrangement can also be carried out in the area of the electric vehicle in which the drive movement is to be generated, for example on a respective drive axle. Furthermore, a parking lock function can be implemented, during which the output shaft is fixed.

In the motor vehicle transmission according to the invention, a first gear is switched between the drive shaft and the output shaft by closing the first switching element, whereas a second gear between the drive shaft and the output shaft is represented by actuating the second switching element. Furthermore, a third gear is switched between the input shaft and the output shaft by closing the third shift element. This advantageously results in a suitable representation of gears of the motor vehicle transmission by appropriate power flow routing via the three planetary gear sets. Successive switching between gears can be achieved by switching between two switching elements. To change from the first gear to the second gear, the first switching element must be opened and the second switching element subsequently actuated, while to shift from the second gear to the third gear, the second switching element must be opened and the third switching element must be closed .

In the motor vehicle transmission according to the invention, the parking lock function is implemented in that the third switching element and the fourth switching element are actuated at the same time. As a result, both the first planetary gear set and the second planetary gear set are blocked, which prevents the output shaft from rotating. In this way, when installed, rotational movements of the drive wheels of a motor vehicle coupled to the output shaft and thus unwanted rolling of the motor vehicle can also be prevented.

The switching elements are preferably designed as positive switching elements, and they are particularly preferably designed as unsynchronized claw switching elements. A design of the switching elements as positive switching elements has the advantage that in an open state of the respective switching element, no or only small drag losses occur on this switching element. This allows the efficiency of the motor vehicle transmission to be improved. Alternatively, one or more of the switching elements can also be designed as positive switching elements in the form of locking synchronizations. Another alternative is to design individual or several switching elements as non-positive switching elements, whereby they can particularly preferably be present as multi-plate switching elements. In this way, the respective switching element can advantageously be actuated under load.

It is an embodiment of the invention that the third switching element, when actuated, connects the third element of the first planetary gear set to the second element of the first planetary gear set in a rotationally fixed manner. In this case, the blocking of the first planetary gear set in the actuated state of the third switching element, which is at least functionally present, is achieved in that the third element of the first planetary gear set is connected in a rotationally fixed manner to the second element of the first planetary gear set.

According to an alternative or supplementary embodiment of the invention, the at least functionally provided fourth switching element, when actuated, connects the first element of the second planetary gear set and the second element of the second planetary gear set to one another in a rotationally fixed manner. In this case, the locking of the second planetary gear set is brought about by a rotationally fixed connection of the first element of the second planetary gear set and the second element of the second planetary gear set via the fourth switching element.

In a further development of a combination of the aforementioned variants, the first switching element, the second switching element, the third switching element and the fourth switching element are formed by a switching device, the coupling element of which is positioned in a first switching position, in a second switching position, in a third switching position and in a fourth switching position can be. In the first switching position, the coupling element functionally represents an actuated state of the first switching element and fixes the third element of the first planetary gear set. In the second switching position, the coupling element functionally represents an actuated state of the second switching element and connects the third element of the first planetary gear set to the second element of the second planetary gear set and the first element of the third planetary gear set in a rotationally fixed manner. In addition, in the third switching position, the coupling element functionally represents an actuated state of the third switching element, in that the coupling element connects the third element of the first planetary gear set to the second element of the first planetary gear set in a rotationally fixed manner. Finally, the coupling element in the fourth switching position functionally represents both the actuated state of the third switching element and the actuated state of the fourth switching element, in that the coupling element in the fourth switching position connects both the third element of the first planetary gear set to the second element of the first planetary gear set in a rotationally fixed manner , as well as the first element of the second planetary gear set in a rotationally fixed connection with the second element of the second planetary gear set. Mapping the functions of the first switching element, the second switching element, the third switching element and the fourth switching element by a switching device has the advantage that the respective, rotationally fixed connections can be implemented in a compact manner and with a low number of components.

Particularly preferably, the coupling element can also be positioned in a neutral position between the first and the second switching position and between the second and the third switching position, with no coupling being carried out via the coupling element in the individual neutral position. In this respect, a first neutral position can be assumed by the coupling element between the first switching position and the second switching position and a second neutral position between the second switching position and the third switching position.

Particularly preferably, the coupling element of the switching device is designed in the manner of a sliding sleeve, which is guided on a guide toothing in a rotationally fixed and axially displaceable manner on a toothing, this toothing being in particular connected in a rotationally fixed manner to the third element of the first planetary gear set. In addition, such a coupling element is in particular equipped with at least one engagement toothing, with which the coupling element engages in the respective toothings in the respective switching positions. The toothings are each connected in a rotationally fixed manner to the component or components of the motor vehicle transmission, which are to be connected in a rotationally fixed manner to the third element of the first planetary gear set in the individual switching position via the coupling element. The coupling element particularly preferably has three engagement teeth.

According to one possible embodiment of the invention, the output shaft is coupled to a differential gear set. The differential gear set functions in particular as a transverse differential, with the differential gear set further preferably being designed in the manner of a bevel gear differential. The differential gear set preferably distributes a drive movement transmitted to the output shaft of the motor vehicle transmission to output shafts of a drive axle of the hybrid or electric vehicle. In particular, the output shaft is coupled to a differential carrier of the differential gear set, whereby this coupling can be carried out, in that the output shaft is connected to the differential carrier in a rotationally fixed manner or carries a spur gear which meshes with a drive ring wheel of the differential carrier. Furthermore, the differential gear set can also form a longitudinal differential, via which a drive power is distributed to several drive axles.

According to one embodiment of the invention, the planetary gear sets are arranged on a connection point of the drive shaft, which serves to couple the drive shaft to the drive machine, in a sequence of first planetary gear set, second planetary gear set and third planetary gear set. In this way, a suitable structure of the electric vehicle transmission according to the invention can be achieved. Within the scope of the invention, however, the planetary gear sets can also be arranged differently in the axial direction following the connection point of the drive shaft.

In a further development of the aforementioned embodiment, the at least functionally provided first switching element, the at least functionally provided second switching element, the at least functionally provided third switching element and the at least functionally provided fourth switching element are arranged axially between the first planetary gear set and the second planetary gear set. If the first switching element, the second switching element, the third switching element and the fourth switching element are formed by a common switching device, then this switching device is then preferably provided axially between the first planetary gear set and the second planetary gear set. In the latter case, there is a control actuator, via which the coupling element of the switching device, which functionally forms the first switching element, the second switching element, the third switching element and the fourth switching element, is moved into the first switching position, into the second switching position, into the third switching position and into the fourth switching position can be transferred, is also placed axially between the first planetary gear set and the second planetary gear set. This actuator is particularly preferably arranged radially on the outside of the first planetary gear set and the second planetary gear set and is connected to the coupling element via an intermediate shift linkage.

The invention also relates to a drive unit, which is preferably an electric axle drive unit and which, in addition to an electric machine, has a motor vehicle transmission according to one or more of the variants described above. A rotor of the electric machine is coupled to the drive shaft of the motor vehicle transmission, this coupling being present in particular as a rotationally fixed connection between the rotor of the electric machine and a connection point of the drive shaft. Alternatively, one or more intermediate transmission stages could also be provided between the drive shaft of the motor vehicle transmission and the rotor of the electric machine, which could be designed specifically as a spur gear stage or as a planetary stage. Within the scope of the invention, the electric machine can be operated, in particular, on the one hand as a generator and on the other hand as an electric motor.

Within the scope of the invention, it would also be conceivable that in the aforementioned drive unit the first planetary gear set of the motor vehicle transmission is arranged axially overlapping with and radially inwardly of the electric machine. In this way, a nested structure of the drive unit can be achieved, which results in an overall axially compact structure.

A drive system designed in accordance with one or more of the aforementioned variants is in particular part of a drive axle, which is intended for a hybrid or electric vehicle. The drive unit is preferably arranged in a plane with output shafts, each of which is assigned to at least one drive wheel and is coupled to the output shaft of the motor vehicle transmission. In this way, a compact design of a drive axle with the drive unit can advantageously be achieved, with the coupling between the output shaft of the motor vehicle transmission and the output shafts of the drive axle being carried out in particular via a differential gear set.

At least one such drive axle is provided within the scope of the invention in a hybrid or electric vehicle, which is in particular a commercial vehicle. The commercial vehicle can in particular be an at least partially electrically powered transporter or a light to medium-duty, at least partially electrically powered bus or truck.

The fact that two components of the motor vehicle transmission are “connected” or “coupled” or “are connected to one another” means, in the sense of the invention, 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 rather the corresponding components are underneath coupled to each other at a fixed speed ratio.

If, on the other hand, a switching element is at least functionally provided between two components, these components are not permanently coupled to one another, but rather a coupling is only carried out by actuating the at least functionally intermediate switching element. In this case, actuation of the switching element in the sense of the invention means that the switching element in question is transferred to a closed state and as a result the components directly coupled to it are adjusted in their rotational movements. If the switching element in question is designed as a positive switching element, the components that are directly connected to one another in a rotationally fixed manner will run at the same speed, while in the case of a non-positive switching element, speed differences can exist between the components even after the same has been actuated. In the context of the invention, this desired or unwanted state is nevertheless referred to as a rotationally fixed connection of the respective components via the switching element.

• 1 eine schematische Darstellung eines Elektrofahrzeugs entsprechend einer bevorzugten Ausführungsform der Erfindung;
• 2 eine schematische Ansicht einer Antriebsachse des Elektrofahrzeugs aus 1 mit einer Antriebseinheit entsprechend einer bevorzugten Ausführungsform der Erfindung, gezeigt in einem ersten Schaltzustand eines Kraftfahrzeuggetriebes der Antriebseinheit;
• 3 die Antriebsachse aus 2, gezeigt in einem zweiten Schaltzustand des Kraftfahrzeuggetriebes der Antriebseinheit;
• 4 die Antriebsachse aus 2, gezeigt in einem dritten Schaltzustand des Kraftfahrzeuggetriebes der Antriebseinheit;
• 5 die Antriebsachse aus 2, gezeigt in einem vierten Schaltzustand des Kraftfahrzeuggetriebes der Antriebseinheit; und
• 6 ein beispielhaftes Schaltschema des Kraftfahrzeuggetriebes der Antriebseinheit aus 2.

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

• 1 a schematic representation of an electric vehicle according to a preferred embodiment of the invention;
• 2 a schematic view of a drive axle of the electric vehicle 1 with a drive unit according to a preferred embodiment of the invention, shown in a first switching state of a motor vehicle transmission of the drive unit;
• 3 the drive axle 2 , shown in a second switching state of the motor vehicle transmission of the drive unit;
• 4 the drive axle 2 , shown in a third switching state of the motor vehicle transmission of the drive unit;
• 5 the drive axle 2 , shown in a fourth switching state of the motor vehicle transmission of the drive unit; and
• 6 an exemplary switching diagram of the motor vehicle transmission of the drive unit 2 .

1 shows a schematic view of an electric vehicle 1, which is in particular an electric commercial vehicle, such as a van. In addition to a steerable, non-driven vehicle axle 2, the electric vehicle 1 also has a drive axle 3, in which a drive unit 4 is provided as an electric axle drive unit. While the vehicle axle 2 is a front axle of the electric vehicle 1, the drive axle 3 is a rear axle of the electric vehicle 1. However, as an alternative or in addition to the drive axle 3, the vehicle axle 2 could also be designed as a driven axle.

In 2 the drive axle 3 and in particular the drive unit 4 are shown in more detail, the latter being implemented in accordance with a preferred embodiment of the invention. As can be seen here, the drive unit 4 is composed of an electric machine 5 and a motor vehicle transmission 6, which is implemented in accordance with a preferred embodiment of the invention. The electric machine 5 is formed in a manner known in principle to those skilled in the art by a stator 7 and a rotor 8, whereby the electric machine 5 can be operated as a generator on the one hand and as an electric motor on the other.

The motor vehicle transmission 6 has, in addition to a drive shaft 9 and an output shaft 10, three planetary gear sets P1, P2 and P3, each consisting of a first element E11 or E12 or E13, a second element E21 or E22 or E23 and each a third element E31 or E32 or E33. The respective first element E11 or E12 or E13 of the respective planetary gear set P1 or P2 or P3 is a respective sun gear, while the respective second element E21 or E22 or E23 of the respective planetary gear set P1 or P2 or P3 is designed as a respective planetary web. In addition, the respective third element E31 or E32 or E33 of the respective planetary gear set P1 or P2 or P3 is present as a respective ring gear of the respective planetary gear set P1 or P2 or P3.

In the respective planetary web of the respective planetary gear set P1 or P2 or P3, at least one planet gear is rotatably mounted, which meshes with both the respective sun gear and the respective ring gear of the respective planetary gear set P1 or P2 or P3. In this respect, the planetary gear sets P1, P2 and P3 are designed as negative planetary gear sets.

Within the scope of the invention, an embodiment of one or more of the planetary gear sets P1 to P3 as a plus planetary gear set is also possible, for which purpose, in comparison to the respective version as a minus planetary gear set, the respective second element E21 or E22 or E23 is provided by the respective ring gear and the respective third element E31 or E32 or E33 is to be formed by the respective planetary web. Furthermore, a stationary gear ratio must be increased by one when the respective planetary gear set is designed as a plus planetary gear set compared to a design as a minus planetary gear set. In a plus planetary set, at least one pair of planetary gears is rotatably mounted in the respective planetary web, of which a planetary gear meshes with the respective sun gear and a planetary gear meshes with the respective ring gear. In addition, the planetary gears of the at least one pair of planetary gears mesh with one another.

In the present case, the first element E11 of the first planetary gear set P1 is connected in a rotationally fixed manner to the drive shaft 9, which is also connected in a rotationally fixed manner to the rotor 8 of the electric machine 5. In this respect, the first element E11 of the first planetary gear set P1 and the rotor 8 are connected to one another in a rotationally fixed manner via the drive shaft 9, as a result of which the first element E11 and the rotor 8 always rotate at the same speed. Within the scope of the invention, the first element E11 of the first planetary gear set P1 can be designed in one piece with the drive shaft 9. The second element E21 of the first planetary gear set P1 is permanently connected in a rotationally fixed manner to the first element E12 of the second planetary gear set P2, so that these two elements E21 and E12 also constantly run at the same speed. Likewise, the second element E22 of the second planetary gear set P2 and the first element E13 of the third planetary gear set P3 are constantly connected to one another in a rotationally fixed manner, whereby the second element E22 of the second planetary gear set P2 and the first element E13 of the third planetary gear set P3 permanently rotate together. The respective rotation-proof connection is preferably made via an intermediate shaft.

As also in 2 As can be seen, the third element E33 of the third planetary gear set P3 is fixed to a permanently fixed component 11 and is therefore constantly prevented from rotating. Here, the component 11 is preferably a gear housing of the motor vehicle transmission 6, a part of such a gear housing or a component connected to it in a rotationally fixed manner. The third element E33 of the third planetary gear set P3 could be designed in one piece with the component 11 within the scope of the invention. The second element E23 of the third planetary gear set P3 and the third element E32 of the second planetary gear set P2, on the other hand, are connected in a rotationally fixed manner to one another and to the output shaft 10 of the motor vehicle transmission 6, whereby the second element E23 of the third planetary gear set P3 and the third element E32 of the second planetary gear set P2 are permanently rotate together with the output shaft 10. Here, the second element E23 of the third planetary gear set P3 and/or the third element E32 of the second planetary gear set P2 may also be formed in one piece with the output shaft 10.

In addition to the second element E23 of the third planetary gear set P3, the output shaft 10 is also permanently connected in a rotationally fixed manner to a differential carrier 12 of a differential gear set 13. This differential gear set 13 is designed in the manner of a bevel gear differential, in which a drive power introduced into the differential carrier 12 via the output shaft 10 is distributed to output shafts 14 and 15 of the drive axle 3 in a manner known in principle to those skilled in the art. A drive wheel 16 or 17 of the drive axle 3 is each drivingly connected to the output shafts 14 and 15.

In the motor vehicle transmission 6, a switching device 18 is also provided, via which different couplings can be implemented by positive locking. The switching device 18 is designed as an unsynchronized switching device, via which four switching elements A, B, C and D are mapped in terms of function, which in 2 are indicated. The switching device 18 has a coupling element 19, which is designed in the manner of a sliding sleeve and is guided in a rotationally fixed manner on a guide toothing 20 and axially displaceable on a toothing 21. The toothing 21 is connected in a rotationally fixed manner to the third element E31 of the first planetary gear set P1. In addition, the coupling element 19 is also equipped with a first engagement toothing 22, a second engagement toothing 23 and a third engagement toothing 24 and can be moved via an associated actuator 25 in four different switching positions and two neutral positions. The actuator 25 is preferably an electromechanical actuator.

In a first switching position, which in 2 is shown, engages the coupling element 19 of the switching device 18 with the engagement teeth 22 in a toothing 26, which is connected to the component 11 in a rotationally fixed manner. In terms of function, this represents an actuated state of the switching element A, in which the third element E31 of the first planetary gear set P1 is fixed to the rotationally fixed component 11 via the coupling element 19 and is therefore prevented from rotating.

From the first switching position, the coupling element 19 of the switching device 18 can be moved via the actuator 25 into a first neutral position, in which the tooth engagement between The engagement toothing 22 and the toothing 26 are canceled and in which the third element E31 of the first planetary gear set P1 is decoupled. From the first neutral position, with further axial movement, in addition to the transfer into the first switching position, the coupling element 19 can also be transferred into a second switching position, which is in 3 shown and in which a tooth engagement on the engagement toothing 23 in a toothing 27 is realized. This toothing 27 is connected in a rotationally fixed manner to the second element E22 of the second planetary gear set P2 and the first element E13 of the third planetary gear set P3. As a result of the tooth engagement, the third element E31 of the first planetary gear set P1 is connected in a rotationally fixed manner via the coupling element 19 to the second element E22 of the second planetary gear set P2 and the first element E13 of the third planetary gear set P3. In terms of function, this second switching position of the coupling element 19 corresponds to an actuated state of the switching element B.

From the second switching position, the coupling element 19 can be moved via the actuator 25 in one axial direction back to the first neutral position and alternatively in the other axial direction into a second neutral position, in which the third element E31 of the first planetary gear set P1 is also completely is decoupled.

The actuator 25 can, on the one hand, transfer the coupling element 19 from the second neutral position back into the second switching position and, on the other hand, into a third switching position by means of an opposite axial displacement. In this third switching position, which in 4 is shown, the coupling element 19 engages on its engagement teeth 24 in a toothing 28, which is permanently connected in a rotationally fixed manner to the second element E21 of the first planetary gear set P1 and the first element E12 of the second planetary gear set P2. This depicts the actuated state of the switching element C, in which the third element E31 of the first planetary gear set P1 is connected in a rotationally fixed manner to the second element E21 of the first planetary gear set P1 and the first element E12 of the second planetary gear set P2. Due to the rotation-proof connection between the second element E21 and the third element E31 of the first planetary gear set P1, this results in the first planetary gear set P1 becoming blocked and thus its block rotation.

From the third switching position, in addition to a backward movement of the coupling element 19 back in one axial direction and thus into the second neutral position, an axially opposite displacement of the coupling element 19 into a fourth switching position is possible, which is in 5 you can see.

In this fourth switching position, in addition to an actuated state of the switching element C, an actuated state of the switching element D is also shown, for which the coupling element 19, in addition to the engagement on the engagement toothing 24 in the toothing 28, also engages with its engagement toothing 23 in a toothing 29. The toothing 29, like the toothing 27, is here connected in a rotationally fixed manner to the second element E22 of the second planetary gear set P2. In this respect, the second element E22 and the first element E12 of the second planetary gear set P2 are also connected to one another in a rotationally fixed manner due to the meshing of the meshing teeth 23 in the teeth 29 due to the simultaneous meshing of the meshing teeth 24 in the teeth 28. This results in the second planetary gear set P2 becoming blocked.

Since the actuated state of the switching element C is also realized in the fourth switching position, the first planetary gear set P1 is blocked again in addition to the second planetary gear set P2. The simultaneous locking of the first planetary gear set P1 and the second planetary gear set P2 results in the output shaft 10 being blocked.

In the present case, the drive unit 4 is arranged parallel to the drive axle 3 and in a plane with the output shafts 14 and 15, with the drive unit 4 lying axially between the drive wheels 16 and 17. Here, the electric machine 5 is arranged axially adjacent to the drive wheel 17, with the first planetary gear set P1 of the motor vehicle transmission 6 being placed axially at the level of and radially on the inside of the stator 7 of the electric machine 5. Axially the first planetary gear set P1 is then followed by the second planetary gear set P2 and then by the planetary gear set P3 and the differential gear set 13, the latter being able to be accommodated together with the planetary gear sets P1 to P3 in a gear housing of the motor vehicle transmission 6.

The switching device 18 is placed axially between the first planetary gear set P1 and the second planetary gear set P2, the switching device 18 being specifically arranged axially between the second planetary gear set P2 and a radial connection of the toothing 26 to the component 11. The actuator 25 of the switching device 18 is also placed axially between the second planetary gear set P2 and this radial connection and radially surrounding the two planetary gear sets P1 and P2, whereby the Actuator 25 is coupled to the coupling element 19 via a switching linkage 30.

Furthermore shows 6 an exemplary switching diagram of the motor vehicle transmission 6 from the 2 until 5 . It can be seen that in the motor vehicle transmission 6, on the one hand, a first gear G1, a second gear G2 and a third gear G3 can be shifted, whereby in the table 6 is each marked with an X, which of the switching elements A, B, C and D formed by the switching device 18 is to be actuated. As described above, to display an actuated state of the respective switching element A or B or C or D, the coupling element 19 is moved into the associated switching position.

The first gear G1 results between the drive shaft 9 and the output shaft 10 by actuating the switching element A. In this case, in this case, the third element E31 of the first planetary gear set P1 is fixed to the component 11 via the coupling element 19, as in 2 is shown.

On the other hand, for switching the second gear G2, the switching element B has to be actuated in terms of function, so that the third element E31 of the first planetary gear set P1 is now connected in a rotationally fixed manner to the second element E22 of the second planetary gear set P2 and the first element E13 of the third planetary gear set P3 is. This condition is in 3 shown. In this respect, to shift from the first gear G1 to the second gear G2, the coupling element 19 of the switching device 18 must be moved from the first switching position (actuated state of the switching element A) via the first neutral position into the second switching position (actuated state of the switching element B).

In addition, the third gear G3 of the motor vehicle transmission 6 is switched by the fact that the switching element C is actuated in terms of function. Accordingly, in the switching device 18, the coupling element 19 must be moved into the switching position in which the engagement teeth 24 are in tooth engagement with the teeth 28, this being the case in 4 is shown. As a result, the third element E31 of the first planetary gear set P1 is connected in a rotationally fixed manner to the second element E21 of the first planetary gear set P1 and the first planetary gear set P1 is thus blocked. To shift from the second gear G2 to the third gear G3, the coupling element 19 of the switching element 18 must be transferred from the second switching position (actuated state of the switching element B) via the second neutral position into the third switching position (actuated state of the switching element C). When changing gears between gears G1 and G2 as well as G2 and G3, the required synchronous speeds on the coupling element 19 are set via the electric machine 5 by appropriate speed control.

Finally, a parking lock function of the motor vehicle transmission can be implemented, for which the switching element C and the switching element D have to be actuated at the same time. This will be done in the in 5 shown switching position of the coupling element 19 of the switching device 18 is realized. As a result, both the first planetary gear set P1 and the second planetary gear set P2 are blocked, whereby the output shaft 10 is prevented from rotating.

By means of the inventive design of a motor vehicle transmission, different gears and a parking lock function can be implemented in a compact manner.

Reference symbols

1

Electric vehicle

2

Vehicle axle

3

Drive axle

4

Drive unit

5

Electric machine

6

Motor vehicle transmission

7

stator

8th

rotor

9

drive shaft

10

output shaft

11

Component

12

Differential basket

13

Differential gear set

14

output shaft

15

output shaft

16

drive wheel

17

drive wheel

18

Switching device

19

Coupling element

20

Guide teeth

21

gearing

22

Mesh gearing

23

Mesh gearing

24

Mesh gearing

25

actuator

26

gearing

27

gearing

28

gearing

29

gearing

30

Shift linkage

P1

First planetary gear set

P2

Second planetary gear set

P3

Third planetary gear set

E11

First element first planetary gear set

E21

second element first planetary gear set

E31

third element first planetary gear set

E12

First element second planetary gear set

E22

second element second planetary gear set

E32

third element second planetary gear set

E13

First element third planetary gear set

E23

second element third planetary gear set

E33

third element third planetary gear set

A

Switching element

b

Switching element

C

Switching element

D

Switching element

G1

First course

G2

Second gear

G3

Third gear

P.S

Parking lock function

QUOTES INCLUDED IN THE DESCRIPTION

This list of documents listed by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• WO 2015/082166 A1 [0003]

Claims (16)

Motor vehicle transmission (6), in particular hybrid or electric vehicle transmission, comprising a drive shaft (9), which is provided for a drive-effective connection to a drive machine, an output shaft (10) and a first planetary gear set (P1), a second planetary gear set (P2) and a third planetary gear set (P3), each of which has a first element (E11, E12, E13), a second element (E21, E22, E23) and a third element (E31, E32, E33) in the form of a sun gear, each a planetary web and each have a ring gear, wherein at least functionally a first switching element (A), a second switching element (B), a third switching element (C) and a fourth switching element (D) are provided, and wherein the first element (E11) of the first planetary gear set (P1) is non-rotatably connected to the drive shaft (9) and the second element (E23) of the third planetary gear set (P3) is non-rotatably connected to the output shaft (10), characterized in that - the third element (E33) of the third planetary gear set (P3) is fixed, - that the third element (E32) of the second planetary gear set (P2) is connected in a rotationally fixed manner to the second element (E23) of the third planetary gear set (P3) and the output shaft (10), - that the second element (E21) of the first planetary gear set (P1) and the first element (E12) of the second planetary gear set (P2) are connected to one another in a rotationally fixed manner, - that the second element (E22) of the second planetary gear set (P2) and the first element (E13) of the third planetary gear set (P3) are connected to one another in a rotationally fixed manner, - that the first switching element (A) is intended to fix the third element (E31) of the first planetary gear set (P1), - that the second switching element (B) is intended to fix the third Element (E31) of the first planetary gear set (P1) to be connected in a rotationally fixed manner to the second element (E22) of the second planetary gear set (P2) and the first element (E13) of the third planetary gear set (P3), - that the third switching element (C) is provided for this purpose is to bring two of the elements (E11, E21, E31) of the first planetary gear set (P1) together in a rotationally fixed manner, - and that the fourth switching element (D) is intended to connect two of the elements (E12, E22, E32) of the second Planetary gear set (P2) to be connected to each other in a rotationally fixed manner. Motor vehicle transmission (6). Claim 1 , characterized in that the switching elements (A, B, C, D) are designed as positive switching elements, preferably as unsynchronized claw switching elements. Motor vehicle transmission (6). Claim 1 or 2 , characterized in that the at least functionally provided third switching element (C) connects the third element (E31) of the first planetary gear set (P1) in a rotationally fixed manner to the second element (E21) of the first planetary gear set (P1) when actuated. Motor vehicle transmission (6) according to one of the Claims 1 until 3 , characterized in that the at least functionally provided fourth switching element (D) connects the first element (E12) of the second planetary gear set (P2) and the second element (E22) of the second planetary gear set (P2) to one another in a rotationally fixed manner when actuated. Motor vehicle transmission (6) according to the Claims 2 , 3 and 4 , characterized in that the first switching element (A), the second switching element (B), the third switching element (C) and the fourth switching element (D) are formed by a switching device (18), the coupling element (19) of which is in a first switching position , can be positioned in a second switching position, in a third switching position and in a fourth switching position, - the coupling element (19) in the first switching position functionally representing an actuated state of the first switching element (A) and the third element (E31) of the first planetary gear set (P1), - the coupling element (19) in the second switching position functionally represents an actuated state of the second switching element (B) and the third element (E31) of the first planetary gear set (P1) is rotationally fixed with the second element (E22) of the second Planetary gear set (P2) and the first element (E13) of the third planetary gear set (P3), - the coupling element (19) in the third switching position functionally represents an actuated state of the third switching element (C) and the third element (E31) of the first planetary gear set (P1) in a rotationally fixed manner with the second element (E21) of the first planetary gear set (P1), - and wherein the coupling element (19) in the fourth switching position functionally represents both the actuated state of the third switching element (C) and that third element (E31) of the first planetary gear set (P1) non-rotatably connects to the second element (E21) of the first planetary gear set (P1), as well as the actuated state of the fourth switching element (D) and the first element (E12) of the second planetary gear set (P2) connects in a rotationally fixed manner to the second element (E22) of the second planetary gear set (P2). Motor vehicle transmission (6) according to one of the preceding claims, characterized in that the output shaft (10) has an on gear side of a differential gear set (13) is coupled. Motor vehicle transmission (6) according to one of the preceding claims, characterized in that the planetary gear sets (P1, P2, P3) are applied to a connection point of the drive shaft (9), which serves for the driving connection of the drive shaft (9) to the drive machine, in a first order Planetary gear set (P1), second planetary gear set (P2) and third planetary gear set (P3) are arranged. Motor vehicle transmission (6). Claim 7 , characterized in that the at least functionally provided first switching element (A), the at least functionally provided second switching element (B), the at least functionally provided third switching element (C) and the at least functionally provided fourth switching element (D) axially between the first planetary gear set (P1 ) and the second planetary gear set (P2) are arranged. Motor vehicle transmission (6). Claim 5 and after Claim 8 , characterized in that a positioning actuator (25), via which the coupling element (19) of the switching device (which functionally forms the first switching element (A), the second switching element (B), the third switching element (C) and the fourth switching element (D) 18) can be moved into the first switching position, into the second switching position, into the third switching position and into the fourth switching position, is placed axially between the first planetary gear set (P1) and the second planetary gear set (P2). Drive unit (4), in particular electric axle drive unit, for a hybrid or electric vehicle (1), comprising an electric machine (5) and a motor vehicle transmission (6) according to one or more of the Claims 1 until 9 , wherein a rotor (8) of the electric machine (5) is coupled to the drive shaft (9) of the motor vehicle transmission (6). Drive unit (4). Claim 10 , characterized in that the first planetary gear set (P1) of the motor vehicle transmission (6) is placed axially at the height and radially inside the electric machine (5). Drive axle (3) for a hybrid or electric vehicle (1), comprising a drive unit (4). Claim 10 or 11 . Drive axle (3). Claim 12 , characterized in that the drive unit (4) is arranged in a plane with output shafts (14, 15), each of which is assigned to at least one drive wheel (16, 17) and is coupled to the output shaft (10) of the motor vehicle transmission (6). Hybrid or electric vehicle (1), comprising at least one drive axle (3). Claim 12 or 13 . Method for operating a motor vehicle transmission (6) according to one or more of the Claims 1 until 9 , wherein a first gear (G1) between the drive shaft (9) and the output shaft (10) by closing the first switching element (A), a second gear (G2) between the drive shaft (9) and the output shaft (10) by actuating the second switching element (B), and a third gear (G3) is switched between the drive shaft (9) and the output shaft (10) by closing the third switching element (C). Method for operating a motor vehicle transmission (6) according to one or more of the Claims 1 until 9 , wherein a parking lock function (PS) is represented by the simultaneous actuation of the third switching element (C) and the fourth switching element (D).

Images