DE102020214534B4 - Compact automotive transmission - Google Patents

Abstract

Transmission (18) for a motor vehicle drive train (12) of a motor vehicle (10), having: a transmission input shaft (34) which is designed to be drivingly connected to an internal combustion engine (16) of the motor vehicle; a first transmission input shaft (22) for a first partial transmission;a second transmission input shaft (24) for a second partial transmission;a first countershaft (26) with a first output for the first partial transmission and/or the second partial transmission;a second countershaft (28) with a second output for the first Sub-transmission and/or the second sub-transmission;Loose wheels and fixed wheels arranged in several wheel set planes for forming gear stages (V1, V2, V3, V4, V5, V6, V7; V8, R1, R2); andseveral gear shifting devices with shifting elements (W, R, A, B, C, D, E) for engaging the gear stages, with a gear-forming gear wheel arranged on the second transmission input shaft meshing with a gear-forming gear wheel on the first countershaft and with a gear-forming gear wheel on the second countershaft ;a top gear (V8) is designed as a direct gear; anda connecting switching element (W) of the switching elements is designed for drivingly connecting the first partial transmission and the second partial transmission in order to set up four winding gear steps.

Description

The present invention relates to a transmission, a motor vehicle drive train with such a transmission and a motor vehicle with such a motor vehicle drive train.

Power-shift transmissions are mostly designed as dual-clutch transmissions. The dual-clutch transmissions known in the prior art have two transmission input shafts and two drive shafts or countershafts, with a plurality of gear wheels being arranged in a meshing manner between the transmission input shafts and the countershafts. In particular, some of the gears are designed as idler gears and other gears as fixed gears, with a respective gear stage, for example the first, second, third gear stage, etc., being formed by two meshing gears. This structure allows a first and second sub-transmission to be formed, with one sub-transmission being able to transmit drive power by means of a clutch assigned to the sub-transmission, while the other sub-transmission is preferably load-free. As a result, a gear can be engaged in the other sub-transmission. By appropriately engaging and disengaging the two individual clutches or the double clutch, one sub-transmission can be shifted load-free, while the other sub-transmission transmits drive power using the engaged gear. It can be switched under load. There is no loss of traction. A disadvantage of such dual clutch transmissions is the large amount of space required.

Double clutch transmissions are also known, in which the gears that mesh with one another are arranged in such a way that at least two so-called “double gear planes” are formed within the double clutch transmission. A double gear plane is formed in particular by a gear wheel arranged on a transmission input shaft, which meshes in particular with one gear wheel of each of the two countershafts, ie with two gear wheels at the same time. Although the space requirement can be reduced as a result, dual clutch transmissions of this type nevertheless have an increased space requirement, in particular because of the two countershafts.

In addition, vehicles are equipped with hybrid drives, ie with at least two different drive sources. Hybrid drives can help reduce fuel consumption and pollutant emissions. Drive trains with an internal combustion engine and one or more electric motors as parallel hybrids or as mixed hybrids have largely become established. Such hybrid drives have a substantially parallel arrangement of the internal combustion engine and the electric drive in the power flow. Here, both a superimposition of the drive torques and control with a purely internal combustion engine drive or purely electric motor drive are made possible. Since the drive torques of the electric drive and the internal combustion engine can add up depending on the activation, a comparatively smaller design of the internal combustion engine and/or its temporary shutdown is possible. In this way, a significant reduction in CO ₂ emissions can be achieved without significant losses in performance or comfort. The possibilities and advantages of an electric drive can thus be combined with the range, performance and cost advantages of internal combustion engines.

From the pamphlet DE 10 2016 210 713 A1 a transmission for a motor vehicle is known, with a transmission shaft, a first shaft, a first idler wheel assigned to the first shaft, a first other idler wheel assigned to the first shaft, a second shaft, a second idler wheel assigned to the second shaft and one assigned to the second shaft second other loose wheel. The transmission shaft can be operatively connected to the first shaft and/or the second shaft. The transmission includes a transmission output shaft, which is operatively connected to the first and second shafts, and a first switching element, by means of which the first loose wheel can be connected in a rotationally fixed manner to the first other loose wheel. When the first switching element is in a closed state, either a first forward gear for forward driving or a sixth forward gear for forward driving can be implemented.

From the pamphlet DE 10 2015 205 307 A1 a double clutch transmission with two clutches is known, the input sides of which are connected to a drive shaft and the output sides of which are connected to one of two coaxially arranged transmission input shafts. Furthermore, at least two countershafts are provided, on which loose wheels are rotatably mounted. The double-clutch transmission comprises fixed gears which are arranged in a rotationally fixed manner on the two transmission input shafts and which mesh with the idler gears, and an output gear wheel which is provided on the two countershafts and which is coupled to a toothing of an output shaft, the output shaft not being arranged coaxially with the input shaft. In addition, several shifting elements are provided, so that at least six power-shiftable forward gears and at least one reverse gear can be shifted. In this case, only three double-acting shifting elements are provided, with each double-acting shifting element being assigned two idler gears of the countershaft, with one of the shifting elements in a first shift direction connects a loose wheel to the associated countershaft and connects the two associated loose wheels to one another in a second direction of action, and two switching elements each connect the associated loose wheels to the associated countershafts in a torque-proof manner.

The disclosure document DE 10 2009 002 354 A1 relates to a dual clutch transmission with two clutches, the input sides of which are connected to an output shaft and the output sides of which are connected to one of two transmission input shafts arranged coaxially with one another. At least two countershafts are provided, on which gear wheels designed as idler gears are rotatably mounted, gear gear wheels designed as fixed wheels being arranged in a rotationally fixed manner and designed as fixed wheels being provided on the two transmission input shafts. At least several power-shiftable forward gears and at least one reverse gear can be shifted. According to the disclosure, a maximum of five wheel planes are provided, so that at least one winding gear that can be shifted under load can be shifted via at least one shifting element.

The disclosure document DE 10 2013 211 591 A1 relates to an arrangement of a transmission and an electric machine for a hybrid drive of a motor vehicle. The transmission is designed as a multi-stage manual transmission with two sub-transmissions. The sub-transmissions each have a separate input shaft and a common output shaft. Both input shafts can be coupled to the common output shaft via interlocking shifting elements of the sub-transmission. A first switchable clutch is assigned to a first input shaft of a first sub-transmission in such a way that the internal combustion engine can be coupled to the first input shaft of the first sub-transmission via the first switchable clutch. A second switchable clutch is assigned to a second input shaft of a second sub-transmission in such a way that the electric machine can be coupled to the second input shaft of the second sub-transmission via the second switchable clutch. The electrical machine can be coupled to the internal combustion engine via a third switchable clutch and to the first input shaft of the first partial transmission via a fourth switchable clutch.

The disclosure document DE 10 2016 202 914 A1 relates to a double clutch transmission for motor vehicles with a first input shaft and a second input shaft, and two clutches, via which the first input shaft and the second input shaft can be selectively coupled to the drive motor. The dual clutch transmission also includes two intermediate shafts arranged parallel to the transmission input shafts, gear wheel pairs of fixed wheels and idler wheels, of which a first gear wheel is arranged on one of the input shafts and a second gear wheel is arranged on one of the intermediate shafts. Furthermore, the dual clutch transmission comprises coupling devices, via which the idler gears can be selectively connected to the respective intermediate shafts, and a driven gear wheel arranged on each of the two intermediate shafts, with the driven gear wheels of both intermediate shafts meshing with the differential and being non-rotatably connected to the respective intermediate shaft alternately by means of one of the coupling devices are.

The disclosure document JP 2016-53 412 A relates to a double-clutch transmission with a first and second transmission input shaft, which are arranged coaxially with one another, and two countershafts designed as hollow shafts, which can be brought into driving connection with one of the transmission input shafts via meshing gear wheel pairs. Furthermore, the dual-clutch transmission comprises two countershafts designed as solid shafts, which can be connected to the countershafts designed as hollow shafts in a drivingly effective manner by means of clutches.

Against this background, a person skilled in the art is faced with the task of creating a compact transmission with a wide range of functions. In particular, all gears should be shiftable under load and the transmission should be advantageously combinable with an electric drive motor.

• einer Getriebeantriebswelle, die dazu ausgebildet ist, antriebswirksam mit einer Verbrennungsmaschine des Kraftfahrzeugs verbunden zu werden;
• einer ersten Getriebeeingangswelle für ein erstes Teilgetriebe;
• einer zweiten Getriebeeingangswelle für ein zweites Teilgetriebe;
• einer ersten Vorgelegewelle mit einem ersten Abtrieb für das erste Teilgetriebe und/oder das zweite Teilgetriebe;
• einer zweiten Vorgelegewelle mit einem zweiten Abtrieb für das erste Teilgetriebe und/oder das zweite Teilgetriebe;
• in mehreren Radsatzebenen angeordneten Losrädern und Festrädern zum Bilden von Gangstufen, und
• mehreren Gangschaltvorrichtungen mit Schaltelementen zum Einlegen der Gangstufen, wobei
• ein an der zweiten Getriebeeingangswelle angeordnetes gangbildendes Zahnrad mit einem gangbildenden Zahnrad auf der ersten Vorgelegewelle und mit einem gangbildenden Zahnrad auf der zweiten Vorgelegewelle kämmt;
• eine höchste Vorwärtsgangstufe als Direktgangstufe ausgebildet ist; und
• ein Verbindungsschaltelement der Schaltelemente zum antriebswirksamen Verbinden des ersten Teilgetriebes und des zweiten Teilgetriebes ausgebildet ist, um vier Windungsgangstufen einzurichten.

This object is achieved by a transmission for a motor vehicle drive train of a motor vehicle, with:

• a transmission input shaft configured to be drivingly connected to an internal combustion engine of the motor vehicle;
• a first transmission input shaft for a first partial transmission;
• a second transmission input shaft for a second partial transmission;
• a first countershaft with a first output for the first partial transmission and/or the second partial transmission;
• a second countershaft with a second output for the first partial transmission and/or the second partial transmission;
• loose wheels and fixed wheels arranged in several wheelset planes to form gear steps, and
• multiple gear shifting devices with switching elements for engaging the gears, wherein
• a gear-forming gear arranged on the second transmission input shaft meshes with a gear-forming gear on the first countershaft and with a gear-forming gear on the second countershaft;
• a highest forward gear is designed as a direct gear; and
• a connecting switching element of the switching elements is designed for drivingly connecting the first sub-transmission and the second sub-transmission in order to set up four winding gears.

• einem Getriebe wie zuvor definiert; und
• einer Verbrennungsmaschine, die mit der Getriebeantriebswelle antriebswirksam verbindbar ist.

The above object is also achieved by a motor vehicle drive train for a motor vehicle, with:

• a gearbox as previously defined; and
• an internal combustion engine, which is drivingly connected to the transmission input shaft.

• einem Kraftfahrzeug-Antriebsstrang wie zuvor definiert; und
• einem Energiespeicher zum Speichern von Energie zum Versorgen der elektrischen Antriebsmaschine.

The above object is also achieved by a motor vehicle with:

• an automotive powertrain as previously defined; and
• an energy store for storing energy for supplying the electric drive machine.

Preferred developments of the invention are described in the dependent claims. It goes without saying that the features mentioned above and those still to be explained below can be used not only in the combination specified in each case, but also in other combinations or on their own, without departing from the scope of the present invention. In particular, the motor vehicle drive train and the motor vehicle can be designed in accordance with the configurations described for the transmission in the dependent claims.

With a first and second transmission input shaft for a first and second partial transmission, a compact variable transmission can be created, which in particular has a large number of gears, which can preferably be shifted under load. An axial compactness of the transmission can be further improved by a first and second countershaft. Furthermore, a gear that forms gears on the second transmission input shaft and meshes with a gear that forms gears on the first countershaft and with a gear that forms gears on the second countershaft can create a highly variable and axially short, i.e. compact, transmission. By designing the highest forward gear as a direct gear, it is possible to drive in this forward gear with little loss, ie efficiently. Consequently, with the transmission provided, efficient high-speed running can be established in the highest forward gear.

The variability and functionality of the transmission can be increased by a connecting shifting element of the shifting elements for drivingly connecting the first partial transmission and the second partial transmission. Winding gear steps can be set up by a connecting shifting element for connecting the first sub-transmission to the second sub-transmission. As a result, for example, a spread of the transmission can be increased. It is also possible to set up a finer gradation of the translation series. It goes without saying that the winding gear stages can also preferably be shifted under load.

In a further advantageous embodiment, the shifting elements are designed as synchronized fluid shifting elements. Additionally or alternatively, at least two of the switching elements are designed as a double switching element and can be actuated by a double-acting actuator. Using positive shifting elements results in a highly efficient transmission. Synchronized shifting elements allow the shifting elements to be engaged preferably without prior synchronization of the transmission. Consequently, it is possible to shift comparatively quickly with synchronized shifting elements. A double shift element makes it possible to construct the transmission with fewer components, since only one actuator has to be used to actuate a double shift element. Since fewer actuators have to be controlled, control of the transmission is simplified.

In a further advantageous embodiment, the second transmission input shaft is designed as a hollow shaft and surrounds the first transmission input shaft at least in sections. In addition, the first transmission input shaft and the second transmission input shaft are arranged axially parallel to the first countershaft and the second countershaft. The first countershaft and the second countershaft define a countershaft plane. In addition, the first transmission input shaft and the second transmission input shaft are arranged radially between the first and second countershafts in a plan view of the countershaft plane. Such an arrangement can further improve the compactness of the transmission. In particular, the installation space available for the transmission can be better utilized. It is understood that the first transmission input shaft and the second transmission input shaft with the first Countershaft and the second countershaft form a triangle in an axial plan view.

In a further advantageous embodiment, the transmission input shaft, the first transmission input shaft and/or the second transmission input shaft are designed to be connected to an electric drive machine in a drivingly effective manner.

Additionally or alternatively, the transmission input shaft is designed to be connected to a dual clutch device, the dual clutch device comprising a first clutch to detachably drive-connect the transmission input shaft to the first transmission input shaft, and a second clutch to detachably connect the transmission input shaft to the second transmission input shaft to connect drivingly. In this way, it can be achieved in particular that all gears for the internal combustion engine and preferably also for the electric drive machine can be shifted under load, since the electric drive machine is preferably arranged in front of the double clutch device in the power flow direction. Furthermore, an external starter for the internal combustion engine can be dispensed with. The transmission can be technically easily converted to a hybrid transmission. It goes without saying that the electric drive machine can be connected to the transmission both as a coaxial machine and parallel to the axis.

In a further advantageous embodiment, an internal combustion engine clutch is provided for the detachable connection of the internal combustion engine to the transmission input shaft. This eliminates the need for the internal combustion engine to be dragged along unnecessarily, particularly if the vehicle is to be driven purely electrically. A transmission with an internal combustion engine clutch can be operated highly efficiently purely electrically. The internal combustion engine clutch can be designed with a friction fit and/or with a form fit. In the case of an internal combustion engine clutch designed in a form-fitting manner, the transmission can be synchronized by means of the electric drive engine when the internal combustion engine is coupled. In the case of a frictionally designed internal combustion engine clutch, the internal combustion engine can be coupled without prior synchronization. Furthermore, a so-called momentum start of the internal combustion engine is possible.

In a further advantageous embodiment, the loose wheels and fixed wheels form six pairs of gears for forming gear steps, which are arranged in four wheel set planes. In addition, the first sub-transmission has three gear pairs, of which two gear pairs can be drivingly connected to the first countershaft and one gear pair can be drivingly connected to the second countershaft. The second partial transmission has three further pairs of gearwheels, of which two pairs of gearwheels can be connected to the second countershaft in a drivingly effective manner and one pair of gearwheels can be connected in a drivingly effective manner to the first countershaft. In addition, the idler gears and fixed gears are designed to form eight power-shiftable forward gears and two reverse gears. In this way, with a compact design of the transmission, a low component load and low transmission losses and good gearing efficiency can be achieved. In particular, a good range of gear ratios can be achieved with four wheelset levels. At least three double switching elements are preferably possible with such an arrangement. Forming eight power-shiftable forward gears leads to increased driving comfort with a transmission of this type. In particular, an advantageous wide spread of the transmission can be achieved. Furthermore, a reverse gear can be set up by a reverse gear which meshes with a gear-forming pair of gears. For example, an idler gear arranged on the second countershaft can mesh with the reverse gear to form the third gear in order to achieve a reversal of the direction of rotation.

In a further advantageous embodiment, the transmission can be connected to an internal combustion engine at a transmission input. In addition, the first output and the second output are arranged on the same side of the transmission as the transmission input. In this way, a transmission can be created that is radially compact, particularly on a side opposite the connection side of the dual clutch device. A transmission of this type is particularly suitable for front transverse or rear transverse installation with a lateral output.

In a further advantageous embodiment, starting from a connection side of the internal combustion engine, a first pair of gearwheels is arranged in a first wheelset plane and can be shifted in a drive-effective manner by inserting a fifth shifting element. A second pair of gears and a third pair of gears are arranged in a second wheel set plane, the second pair of gears being switchable in a drive-effective manner by inserting a third shifting element and the third pair of gears by inserting a first shifting element. In addition, a fourth pair of gears and a fifth pair of gears are arranged in a third wheel set plane, the fourth pair of gears being driveably switchable by engaging a second shifting element and the fifth pair of gears by engaging a reverse gear shifting element. Furthermore, there is a sixth pair of gears in a fourth wheel set level arranged and effective drive switchable by inserting a fourth switching element. With such an arrangement of the gear pairs in the wheel set levels, a connection between the loose wheels of the second wheel set level and the third wheel set level can advantageously be set up by means of the connecting switching element, so that at least three forward gears can be designed as winding gears. An advantageous range of gear ratios for all forward gears can be achieved. In other words, this can result in a small step-up or step-down between the second and third wheel set level by connecting the first and second partial transmission, so that the ratios that can be set using the direct gears can be pre-translated in such a way that preferably adjacent gears can be created as winding gears.

In a further advantageous embodiment, a first forward gear can be set up by closing the connecting shifting element and a first shifting element. A second forward gear can be set up by closing the first shifting element. In addition, a third forward gear can be set up by closing a second shifting element. A fourth forward gear can be set up by closing a third shifting element. Furthermore, a fifth forward gear can be set up by closing a fourth shifting element. A sixth forward gear can be set up by closing the connecting switching element and the fourth switching element. A seventh forward gear can be set up by closing the connecting switching element and a fifth switching element. Furthermore, an eighth forward gear can be set up by closing the fifth shifting element. A first reverse gear stage can be set up by engaging a reverse gear shifting element. In addition, a second reverse gear can be set up by engaging the connecting shifting element and the reverse gear shifting element. Of the gears, a first forward gear, a sixth forward gear and a seventh forward gear are designed as winding gears. In addition, one of the reverse gears is designed as a winding gear. As a result, a functionality of the transmission can be expanded without increasing the space required for the transmission. In particular, the gears that are used less frequently during operation are designed as winding gears, so that a high degree of variability and a sufficiently high level of efficiency can be achieved with a high compactness of the transmission.

In a further advantageous embodiment, the motor vehicle drive train has a previously defined transmission, in which the transmission drive shaft is designed to be drivingly connected to an electric drive machine and an electric drive machine that can be drivingly connected to the transmission drive shaft. As a result, a hybrid transmission can be created in a technically simple manner.

In a further advantageous embodiment, the electric drive machine can be controlled as a starter generator for starting the internal combustion engine. In addition or as an alternative, the electric drive machine can be controlled as a charging generator for charging an energy store. The motor vehicle drive train can be operated in a highly efficient manner by controlling the electric drive machine as a starter generator and/or as a charging generator. Fuel consumption can be reduced. In addition, an additional starter for the internal combustion engine can be dispensed with. A cost-efficient hybrid drive train can be created which, in particular, has a large range of functions.

In a further advantageous embodiment, the electric drive machine is arranged axially parallel to the transmission input shaft and is connected to the transmission input shaft in a drivingly effective manner by means of a traction mechanism and/or a wheel set. Alternatively, the electric drive machine is designed as a coaxial machine and the dual clutch device and/or the internal combustion engine clutch is arranged at least in sections radially and/or axially inside the electric drive machine. By arranging the electric drive machine parallel to the axis, the installation space for the dual clutch device and the internal combustion engine clutch is not determined by the electric drive machine. The gear can be made shorter axially. Furthermore, more design freedom can be created for arranging the internal combustion engine clutch and the double clutch device. By designing the electric drive machine as a coaxial machine, a radially compact transmission can be created, since the internal combustion engine clutch and/or the double clutch device can preferably be arranged radially and/or axially inside the electric drive machine. It is particularly advantageous that a traction mechanism and/or a gear chain, ie further components, can be dispensed with. The transmission can be designed to be weight-optimized.

To shift a so-called winding gear, two partial transmissions are preferably coupled to one another. For example, a switching element can be provided which has a non-rotatable Connection between two idler gears of a countershaft allows without connecting the idler gears themselves to the countershaft.

In the present case, an actuator is in particular a component that converts an electrical signal into a mechanical movement. Preferably, actuators used with double switching elements perform movements in two opposite directions in order to switch one switching element of the double switching element in the first direction and to switch the other switching element in the second direction.

A gear step change takes place in particular by disengaging a shifting element and/or a clutch and simultaneously engaging the shifting element and/or the clutch for the next higher or lower gear step. The second shifting element and/or the second clutch thus gradually takes over the torque from the first shifting element and/or the first clutch until, at the end of the gear stage change, the entire torque is taken over by the second shifting element and/or the second clutch. With prior synchronization, a gear change can take place more quickly, and positive-locking shifting elements can preferably be used in this case.

An internal combustion engine can be, in particular, any machine that can generate a rotary movement by burning a drive medium, such as gasoline, diesel, kerosene, ethanol, liquid gas, LPG, etc. An internal combustion engine can be, for example, an Otto engine, a diesel engine, a Wankel engine or a two-stroke engine.

• 1 eine schematische Darstellung eines Systems gemäß einem Aspekt der vorliegenden Erfindung;
• 2 eine Variante eines erfindungsgemäßen Getriebes;
• 3 eine weitere Variante eines erfindungsgemäßen Getriebes;
• 4 eine Schaltmatrix der Getriebe gemäß der 2 und 3;
• 5 eine weitere Variante eines erfindungsgemäßen Getriebes;
• 6 eine weitere Variante eines erfindungsgemäßen Getriebes;
• 7 eine weitere Variante eines erfindungsgemäßen Getriebes;
• 8 eine Schaltmatrix der Getriebe gemäß der 6 und 7;
• 9 eine weitere Variante eines erfindungsgemäßen Getriebes; und
• 10 eine weitere Variante eines erfindungsgemäßen Getriebes.

The invention is described and explained in more detail below using a few selected exemplary embodiments in connection with the accompanying drawings. Show it:

• 1 a schematic representation of a system according to an aspect of the present invention;
• 2 a variant of a transmission according to the invention;
• 3 another variant of a transmission according to the invention;
• 4 a switching matrix of the transmission according to the 2 and 3 ;
• 5 another variant of a transmission according to the invention;
• 6 another variant of a transmission according to the invention;
• 7 another variant of a transmission according to the invention;
• 8th a switching matrix of the transmission according to the 6 and 7 ;
• 9 another variant of a transmission according to the invention; and
• 10 another variant of a transmission according to the invention.

In 1 a motor vehicle 10 with a motor vehicle drive train 12 is shown schematically. The motor vehicle drive train 12 has an optional electric drive motor 14 and an internal combustion engine 16 which are connected to a front axle of the motor vehicle 10 by means of a transmission 18 . It goes without saying that a connection to a rear axle of motor vehicle 10 is also possible. Drive power from internal combustion engine 16 and/or optional electric drive machine 14 is supplied to the wheels of motor vehicle 10 by means of motor vehicle drive train 12 .

The motor vehicle 10 also has an energy store 20 to store energy that is used to supply the optional electric drive machine 14 . It goes without saying that a motor vehicle drive train 12 without an electric drive machine 14 can also be created in the present case. In the case of a purely internal combustion engine motor vehicle drive train 12 , the energy store 20 is preferably a fuel tank and/or a motor vehicle battery, in particular a starter battery, in order to start the internal combustion engine 16 .

2 shows a first variant of a transmission 18 according to the invention. The transmission 18 comprises a first transmission input shaft 22 and a second transmission input shaft 24. The first transmission input shaft 22 is designed as a solid shaft. The second transmission input shaft 24 is designed as a hollow shaft and surrounds the first transmission input shaft 22 at least in sections.

The transmission 18 also includes a first countershaft 26 and a second countershaft 28. A first output pinion Ab1 is arranged on the first countershaft 26, which is designed as a fixed wheel and meshes with a fixed wheel arranged on a differential of an output 30. A second output pinion Ab2 is arranged on the second countershaft 28 and also meshes with the fixed wheel arranged on the differential or is connected in a drivingly effective manner to the differential of the output 30 .

A fixed wheel is arranged on the second transmission input shaft 24 and meshes with a loose wheel to form the seventh and eighth forward gear. The loose wheel to form the seventh and ah The tenth forward gear stage is arranged on the second countershaft 28 and can be connected to it in a drivingly effective manner by engaging a fifth shifting element E. A further fixed wheel is arranged on the second transmission input shaft 24 and is in engagement with a loose wheel of the first and second forward gear and in engagement with the loose wheel of the fourth forward gear.

The loose wheel of the first and second forward gear stage is arranged on the first countershaft 26 and can be connected to the first countershaft 26 in a drivingly effective manner by engaging a first shifting element A.

The loose wheel of the fourth forward gear stage is arranged on the second countershaft 28 and can be drivingly connected to the second countershaft 28 by engaging a third shifting element C.

A fixed wheel is arranged on the first transmission input shaft 22 and meshes with a loose wheel of the third forward gear. The loose wheel of the third forward gear stage is arranged on the second countershaft 28 and can be connected to the second countershaft 28 in a drivingly effective manner by engaging a second shifting element B. The fixed wheel is also drivingly connected to a loose wheel of a first and second reverse gear. The loose wheel of the first and second reverse gear stage is arranged on the first countershaft 26 and can be connected to the first countershaft 26 in a drivingly effective manner by engaging a reverse gear shift element R. It goes without saying that when the fixed gear and the idler gear of the reverse gear are connected, a reversal of the direction of rotation is set up, for example by an additional gear wheel, in order to enable reversing by means of the transmission 18 .

A loose wheel is arranged on the first transmission input shaft 22 and meshes with a fixed wheel of the fifth and sixth forward gear. The fixed wheel of the fifth and sixth forward gear is arranged on the first countershaft 26 . The loose wheel for setting up the fifth and sixth forward gear stage can be connected to the first transmission input shaft 22 in a drive-effective manner by engaging a fourth shifting element D.

On the second countershaft 28 there is also a connecting switching element Wan which can drive the idler gears of the third forward gear and the fourth forward gear together without establishing a driving connection to the second countershaft 28 .

The fifth switching element E is combined with the third switching element C to form a double switching element. The connection switching element W is combined with the second switching element B to form a double switching element. The fourth switching element D is designed as a single switching element. The first switching element A is combined with the reverse gear switching element R to form a double switching element.

A parking lock gear is arranged on the first countershaft 26 between the first output pinion Ab1 and the idler gear of the first and second forward gear, which is shown in dashed lines and is labeled P.

The first transmission input shaft 22 and the second transmission input shaft 24 are arranged on a transmission axis A1. The first countershaft 26 is arranged on a transmission axis A2. The second countershaft 28 is arranged on a transmission axis A3. The output 30 and in particular a differential of the output 30 is arranged on a transmission axis A4.

Furthermore, the gears that can be set by means of the gears are labeled on the gears for better understanding, the gears that can be set by means of the gears or pairs of gears being labeled only radially on the outside for reasons of clarity.

In addition, the gear pairs are numbered with Z1 to Z6. The first pair of gears Z1 is arranged in the first wheel set plane as seen from a connection side of the internal combustion engine 16 (not shown) and is designed to set up the seventh and eighth forward gears V7, V8.

The second pair of gears Z2 and the third pair of gears Z3 are arranged in the second wheel set plane, as seen from a connection side of the internal combustion engine 16 (not shown). The second pair of gears Z2 is designed to set up the fourth forward gear V4. The third pair of gears Z3 is designed to set up the first and second forward gears V1, V2.

The fourth pair of gears Z4 and the fifth pair of gears Z5 are arranged in the third wheel set plane as seen from a connection side of the internal combustion engine 16 (not shown). The fourth gear pair Z4 is designed to set up the third forward gear V3. The fifth pair of gears Z5 is designed to set up the first and second reverse gears R1, R2, wherein the fifth pair of gears Z5 comprises two gears that are attached to the countershafts 26, 28 arranged in order to set up a reversal of the direction of rotation.

The sixth pair of gears Z6 is arranged in the fourth wheel set plane, viewed from a connection side of the internal combustion engine 16 (not shown), and is designed to set up the fifth and sixth forward gears V5, V6.

In 3 a further variant of a transmission 18 according to the invention is shown. In contrast to the in 2 shown embodiment of a transmission 18, the fifth shifting element E is arranged on the second transmission input shaft 24. It goes without saying that the pair of gears Z1 for forming the seventh and eighth forward gear is therefore reversed. The fixed wheel for forming the seventh and eighth forward gear is arranged on the second countershaft 28 and the loose wheel for the seventh and eighth forward gear is arranged on the second transmission input shaft 24 and can be connected to the second transmission input shaft 24 in a drive-effective manner by means of the fifth shifting element E. It goes without saying that the same reference symbols refer to the same features and are not explained again.

In 4 is a switching matrix 32 of the transmission 18 according to FIG 2 and 3 shown. The switching states of the transmission 18 can be described in the switching matrix 32 . For this purpose, the forward gears V1 to V8 and R1 and R2 are named in the first column. The shifting states of the connecting shifting element W, the reverse shifting element R and the first to fifth shifting elements A to E are shown in the second to eighth columns, with an "X" meaning that the respective shifting element is closed, i.e. drivingly connects the transmission components assigned to the shifting element with one another . It goes without saying that if there is no “X” in the switching matrix 32, the clutch or the corresponding switching element is to be regarded as open, ie not transmitting any drive power.

To set up the first reverse gear stage R1, the reverse gear shifting element R must be closed.

Closing the connecting switching element W and the first switching element A establishes the first forward gear stage V1.

The third forward gear V3 can be set up by closing the second switching element B.

Closing the fourth switching element D establishes the fifth forward gear stage V5.

The seventh forward gear stage can be set up by closing the connecting switching element W and the fifth switching element E.

The gear steps described above can be set up by means of the first transmission input shaft 22 . The first forward gear V1 and the seventh forward gear V7 are designed as winding gears, the other gears described so far are designed as direct gears. The gears that now follow can be set up by means of the second transmission input shaft 24 .

The second reverse gear stage R2 is designed as a winding gear stage and can be set up by engaging the connecting switching element W and the reverse gear switching element R.

The second forward gear is designed as a direct gear and is set up by engaging the first shift element A.

The fourth forward gear is also a direct gear and can be set up by engaging the third shift element C.

The sixth forward gear is designed as a winding gear and can therefore be set up by engaging the shifting element W and additionally engaging the fourth shifting element D.

The eighth forward gear is designed as a direct gear and can be set up by engaging the fifth shifting element E.

In 5 a further variant of a transmission 18 according to the invention is shown. In contrast to the in 2 variant shown, the fourth shifting element D is arranged on the first countershaft 26 . Consequently, the gear pair Z6 for setting up the fifth and sixth forward gear is reversed, i.e. the fixed gear of the fifth and sixth forward gear is arranged on the first transmission input shaft 22 and the idler gear of the fifth and sixth forward gear is arranged on the first countershaft 26. By means of the fourth shifting element D, the loose wheel of the fifth and sixth forward gear can be connected to the first countershaft 26 in a drivingly effective manner. It is understood that the switching states of the transmission 18 according to the 5 through the switching matrix 32 of 4 can be described.

In 6 a further variant of a transmission 18 according to the invention is shown. In contrast to the in 2 embodiment shown, the transmission 18 of 6 a transmission input shaft 34, which is preferably designed to, with the combustion dimensions, not shown appear 16 to be connected. Furthermore, the transmission 18 according to the 6 a dual clutch device 36 comprising a first clutch K1 and a second clutch K2. By closing the first clutch K1, the transmission drive shaft 34 can be connected to the first transmission input shaft 22 in a drivingly effective manner. Closing the second clutch K2 drivingly connects the second transmission input shaft 24 to the transmission input shaft 34.

In 7 a further variant of a transmission 18 according to the invention is shown. In contrast to the in 3 shown variant, the gear 18 of 7 a double clutch device 36, comprising a first clutch K1 and a second clutch K2. The double clutch device 36 is drivingly connected to the transmission input shaft 34 and can, as already mentioned 6 described, the first transmission input shaft 22 and the second transmission input shaft 24 by closing the corresponding clutches K1, K2 drivingly connect to the transmission input shaft 34.

In 8th is a switching matrix 38 of the transmission 18 according to the 6 and 7 shown. In contrast to the in 4 The switching matrix 32 shown includes the switching states of the first clutch K1 and the second clutch K2. Furthermore, the gear steps are shown in ascending order. The forward gears V1 to V8 as well as the two reverse gears R1 and R2 shift in the same way as in FIG 4 switching states shown. The first clutch K1 is also to be closed for the odd forward gears and the first reverse gear R1. For the even forward gears and the second reverse gear R2, the second clutch K2 must also be closed.

In 9 a further variant of a transmission 18 according to the invention is shown. In contrast to the in 6 shown embodiment of a transmission 18 is arranged on the transmission input shaft 34, an internal combustion engine clutch K0. Furthermore, an electric drive machine 14 is connected to the transmission 18 after the internal combustion engine clutch K0 in the power flow direction. The electric drive machine 14 is designed as a coaxial machine, so that the internal combustion engine clutch K0 and the double clutch device 36 are arranged radially and axially inside the electric drive machine 14 at least in sections. An internal combustion engine 16 arranged on the transmission input shaft 34 can be decoupled from the transmission 18 by the internal combustion engine clutch K0. As a result, the transmission 18 can be operated purely electrically by the electric drive machine 14 . The forward gears V1 to V8 and the reverse gears can consequently be used as pure electric gears.

In 10 a further variant of a transmission 18 according to the invention is shown. In the 10 The illustrated embodiment of a transmission 18 essentially corresponds to that in 9 illustrated embodiment, the internal combustion engine clutch K0 and the electric drive motor 14 being connected to the transmission here as well.

In contrast to the in 9 In the embodiment shown, the electric drive machine 14 is designed as an axis-parallel electric drive machine and is connected to the gearbox 18 by means of a traction drive, a gear chain or another connection method known in principle from the prior art. Consequently, the transmission 18 corresponds to 10 functional to the in 9 gear shown. The electric drive machine 14 is arranged on a transmission axis A5.

An arrangement of the electric drive machine 14 according to the 9 and 10 corresponds to a so-called P1 or P2 arrangement. For a P1 arrangement, the internal combustion engine clutch K0 would be dispensed with. In this respect, the figures show a P2 arrangement, that is to say with an internal combustion engine clutch K0. The internal combustion engine clutch K0 allows an internal combustion engine 16 arranged on the transmission drive shaft 34 in front of the internal combustion engine clutch K0 in the direction of power flow to be decoupled from the transmission 18 when driving purely electrically. Consequently, in the decoupled state, all gears of the transmission 18 can be used purely electrically. The internal combustion engine clutch K0 can optionally be designed as a frictional and/or positive clutch.

The invention has been comprehensively described and explained with reference to the drawings and the description. The description and explanation are intended to be exemplary and not limiting. The invention is not limited to the disclosed embodiments. Other embodiments or variations will become apparent to those skilled in the art upon use of the present invention upon a study of the drawings, the disclosure, and the claims that follow.

In the claims, the words "comprising" and "having" do not exclude the presence of other elements or steps. The undefined article "a" or "an" does not exclude the presence of a plural. A single ele ment or a single unit can perform the functions of several of the units specified in the claims. The mere naming of some measures in several different dependent patent claims should not be understood to mean that a combination of these measures cannot also be used to advantage. Reference signs in the claims are not to be understood as restrictive.

Reference List

10

motor vehicle

12

automotive powertrain

14

electric drive machine

16

combustion engine

18

transmission

20

energy storage

22

first transmission input shaft

24

second transmission input shaft

26

first countershaft

28

second countershaft

30

downforce

32

switching matrix

34

transmission drive shaft

36

dual clutch device

38

switching matrix

A1 to A5

gear axles

A to F

switching elements

W

connection switching element

R

reverse gear shift element

K0

internal combustion engine clutch

K1

first clutch

K2

second clutch

Ab1

first output gear

Starting at 2

second output gear

Z1 to Z6

gear pairs

Claims (14)

Transmission (18) for a motor vehicle drive train (12) of a motor vehicle (10), with: a transmission input shaft (34) adapted to be drivingly connected to an internal combustion engine (16) of the motor vehicle; a first transmission input shaft (22) for a first partial transmission; a second transmission input shaft (24) for a second partial transmission; a first countershaft (26) with a first output for the first partial transmission and/or the second partial transmission; a second countershaft (28) with a second output for the first partial transmission and/or the second partial transmission; loose wheels and fixed wheels arranged in several wheelset planes to form gear steps (V1, V2, V3, V4, V5, V6, V7; V8, R1, R2); and several gear shifting devices with switching elements (W, R, A, B, C, D, E) for engaging the gear stages, wherein a gear-forming gear arranged on the second transmission input shaft meshes with a gear-forming gear on the first countershaft and with a gear-forming gear on the second countershaft; a top gear (V8) is designed as a direct gear; and a connecting switching element (W) of the switching elements is designed for drivingly connecting the first partial transmission and the second partial transmission in order to set up four winding gears. Transmission (18) according to any one of the preceding claims, wherein the switching elements (W, R, A, B, C, D, E) are designed as synchronized positive-locking switching elements; and or at least two of the switching elements are designed as a double switching element and can be actuated by a double-acting actuator. Transmission (18) according to any one of the preceding claims, wherein the second transmission input shaft (24) is designed as a hollow shaft and at least partially surrounds the first transmission input shaft (22); the first transmission input shaft and the second transmission input shaft are arranged axially parallel to the first countershaft (26) and the second countershaft (28); the first countershaft and the second countershaft define a countershaft plane; and the first transmission input shaft and the second transmission input shaft are arranged radially between the first and second countershafts in a plan view of the countershaft plane. Transmission (18) according to any one of the preceding claims, wherein the transmission input shaft (34), the first transmission input shaft (22) and / or the second transmission input shaft (24) are designed to be drivingly connected to an electric drive machine (14); and or the transmission input shaft is designed to be connected to a dual clutch device (36), wherein the dual clutch device comprises a first clutch (K1) to detachably drivingly connect the transmission input shaft to the first transmission input shaft, and a second clutch (K2) to the Transmission input shaft to be detachably connected to the second transmission input shaft in a drivingly effective manner. Transmission (18) according to one of the preceding claims, with an internal combustion engine clutch (K0) for detachably connecting the internal combustion engine (16) to the transmission input shaft (34). Transmission (18) according to any one of the preceding claims, wherein the loose wheels and fixed wheels to form gears (V1, V2, V3, V4, V5, V6, V7; V8, R1, R2) form six pairs of gears (Z1, Z2, Z3, Z4, Z5, Z6), which are divided into four wheel set levels are arranged; the first partial transmission has three gear pairs, of which two gear pairs can be drivingly connected to the first countershaft (26) and one gear pair can be drivingly connected to the second countershaft (28); the second sub-transmission has three further pairs of gears, of which two pairs of gears can be drivingly connected to the second countershaft and one pair of gears can be drivingly connected to the first countershaft; and the loose wheels and fixed wheels are designed to form eight power-shiftable forward gears and two reverse gears. Transmission (18) according to any one of the preceding claims, wherein the transmission can be connected to an internal combustion engine (16) at a transmission input; and the first output and the second output are arranged on the same transmission side as the transmission input. Transmission (18) according to any one of the preceding claims, starting from a connection side of the internal combustion engine (16). a first pair of gear wheels (Z1) is arranged in a first wheel set plane and can be shifted in a drive-effective manner by engaging a fifth shifting element (E); a second pair of gears (Z2) and a third pair of gears (Z3) are arranged in a second wheel set plane, wherein the second pair of gears can be switched in a drive-effective manner by engaging a third shifting element (C) and the third pair of gears by engaging a first shifting element (A); a fourth pair of gears (Z4) and a fifth pair of gears (Z5) are arranged in a third wheel set plane, wherein the fourth pair of gears can be switched in a drive-effective manner by engaging a second shifting element (B) and the fifth pair of gears by engaging a reverse gear shifting element (R); and a sixth pair of gears is arranged in a fourth wheel set plane and can be switched to act as a drive by inserting a fourth shifting element (D). Transmission (18) according to any one of the preceding claims, wherein a first forward gear stage (V1) can be set up by closing the connecting switching element (W) and a first switching element (A); a second forward gear stage (V2) can be set up by closing the first switching element (A); a third forward gear stage (V3) can be set up by closing a second switching element (B); a fourth forward gear stage (V4) can be set up by closing a third switching element (C); a fifth forward gear stage (V5) can be set up by closing a fourth switching element (D); a sixth forward gear stage (V6) can be set up by closing the connecting switching element (W) and the fourth switching element (D); a seventh forward gear stage (V7) can be set up by closing the connecting switching element (W) and a fifth switching element (E); an eighth forward gear stage (V8) can be set up by closing the fifth switching element; a first reverse gear stage (R1) can be set up by closing a reverse gear switching element (R); and a second reverse gear stage (R2) can be set up by closing the connecting switching element (W) and the reverse gear switching element (R). Motor vehicle drive train (12) for a motor vehicle (10), with: a transmission (18) according to any one of the preceding claims; and an internal combustion engine (16) which can be actively connected to the transmission drive shaft (34). Motor vehicle drive train (12) after claim 10 , with a gear (18) after claim 4 ; and an electric drive machine (14) which can be drivingly connected to the transmission input shaft (34). Motor vehicle drive train (12) after claim 11 , wherein the electric drive machine (14) can be controlled as a starter generator for starting the internal combustion engine (16); and/or can be controlled as a charging generator for charging an energy store (20). Motor vehicle drive train (12) according to one of Claims 11 or 12 , wherein the electric drive machine (14) is arranged axially parallel to the transmission input shaft (34) and is drivingly connected to the transmission input shaft by means of a traction mechanism and/or a wheel set; or the electric drive machine (14) is designed as a coaxial machine and the dual clutch device (36) and/or the internal combustion engine clutch (K0) is arranged at least in sections radially and/or axially inside the electric drive machine. Motor vehicle (10) comprising: a motor vehicle powertrain (12) according to any one of Claims 11 until 13 ; and an energy store (20) for storing energy for supplying the electric drive machine (14).

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