WO2014166541A1 - Gearbox and method for operating the gearbox - Google Patents

Abstract

The invention relates to a gearbox for motor vehicles, which gearbox can be shifted between a plurality of gear steps, comprising four degrees of freedom, wherein one of the degrees of freedom is a first input (10), one of the degrees of freedom is a second input (20), one of the degrees of freedom is an output (40), and one of the degrees of freedom is an intermediate degree of freedom (30), at least two shiftable connections (I1, I2), usable for forward gears, between the first input (10) and the intermediate degree of freedom (30), at least two shiftable connections (X1, X2), usable for forward gears, between the intermediate degree of freedom (30) and the output (40), at least two shiftable connections (II, VI), usable for forward gears, between the second input (20) and the output (40), and at least one shiftable connection (II1, R), usable for a forward gear, between the second input (20) and the intermediate degree of freedom (30).

Description

 GEARBOX AND METHOD FOR OPERATING THE GEARBOX

description

The invention relates to a transmission for motor vehicles, which is switchable between a plurality of gear shift stages, with two inputs and one output. The two inputs can either be drive-connected with a drive motor, such as an internal combustion engine.

Such a transmission is disclosed for example in DE 100 15 336 A1. The dual-clutch transmission described therein comprises two input shafts which are each connectable to a drive motor with a friction clutch. Each of the input shafts is connectable via two pairs of gears optionally with an output shaft. Depending on which of the two friction clutches is closed, thus the drive torque is transmitted from the drive motor via the first input shaft to the output shaft or via the second input shaft to the output shaft. Thus, a total of four gear ratios of the transmission could be realized. In order to increase the number of gear shift stages, an intermediate shaft is provided, which is drivingly connected to one of the input shafts via a pair of gears with two fixed wheels. The intermediate shaft is also selectively connectable via one of two gear pairs with the other input shaft. Thus, at least at a certain engaged gear shift stage, the powertrain can be formed from the first input shaft, the intermediate shaft, the second input shaft and the output shaft. Alternatively, the powertrain may be formed of the second input shaft, the intermediate shaft, the first input shaft and the output shaft. Thus theoretically twelve gear shift stages can be realized.

Dual-clutch transmissions have become an alternative to the conventional automatic transmissions with torque converter on the basis of their fuel consumption advantage Market established. One reason for the fuel consumption advantage of the dual-clutch transmission is that for start-up no torque converter, but dry or wet-running clutches are used. However, the torque converter as a starting element has two major advantages over clutches. It provides a high start-up performance through its boost in engine torque and is extremely thermally robust, which also endures long periods of creep or multiple starts on the mountain with a trailer. In contrast, especially the particularly efficient dual-clutch transmission with dry clutches are much more sensitive, which can lead to emergency shutdown of the transmission under unfavorable operating conditions.

One way to solve the problems mentioned and to achieve even with dual-clutch transmissions equal to the conventional automatic transmissions starting power and robustness, is the enlargement of the transmission spread by the introduction of extremely short Anfahrübersetzungen. With greatly increased transmission spread, however, additional gears are required, otherwise either the gear jumps are too large or no long runs consuming low consumption can be implemented. In conventional concepts for dual-clutch transmissions own gear connection or a separate gear pair is generally required for each gear, which is why the mechanical complexity increases with increasing number of gears and thus space requirements due to a high construction space requires s leads. With conventional dual-clutch transmissions, seven forward gears are usually realized today.

In order to realize a favorable switching sequence with a high number of usable gearshift stages, without appreciably increasing the installation space of the gearbox, DE 10 201 1050 083 A1 proposes a gearbox which has two inputs and one output, wherein between the two inputs a usable for forward gears, switchable connection is arranged and between the two inputs and the output in each case three usable for forward gears, switchable connections are arranged. This transmission allows by its arrangement, in particular by the connection between the two inputs and the three connections between the two inputs and the output, a maximum number of gears with low mechanical complexity.

The two inputs and the output form three degrees of freedom of the gearbox, one degree of freedom of which covers all parts of a gearset, e.g. Shafts and gears, which are drivingly connected to each other without the operation of switching elements. The three degrees of freedom can be coupled with each other via switchable connections. In the present case, a total of at least seven connections for forward gears are provided, so that only four shift forks are required for switching, even if there is still a connection for a reverse gear. Here, as usual, a shift fork switch two connections. Due to the connection between the two inputs, the three direct connections for forward gears between the first input and the output can be used in total for six forward gear shift stages of the transmission. The three connections can be used to drive the output directly from the first input. Further, it is possible to drive the output through the second input by the second input via the connection between the two inputs drives the first input and the first input then via one of the three connections the output. The same applies to the three direct connections for forward gears between the second input and the output, which can be used to realize a direct drive between the second input and the output and an indirect output from the first input via the second input to the output , Thus theoretically a total of twelve forward gears can be realized with four shift forks.

For switching between two gear shift stages, in particular between two successive gear shift stages, on the one hand a conventional sequence as provided for conventional dual-clutch transmissions is used, wherein the shift of an outgoing gear shift stage, in which the drive via one of the two inputs, to a higher or lower follower gear shift stage, where the drive is via the other of the two inputs, "Overshooting" is accomplished by continuously closing a clutch to drive the sequential gear shift stage while continuously opening a clutch to drive the outgoing gear shift stage This "crossfade" from one gear to the other occurs without interruption of traction.

On the other hand, a so-called support circuit must be provided to realize the high number of gears. Here, in the shift from an outgoing gear shift stage to a subsequent gear shift stage, wherein both in the outgoing gear shift stage and in the subsequent gear shift the drive via the same of the two inputs, initially in a support gear shift stage switched ("blended"), in During the drive via the other of the two inputs, the follower gear shift stage is engaged and then switched to the subsequent gear shift stage in which the drive takes place via the same input, which is also used to drive the outgoing The term "engage" the sequential gear shift stage means that those connections are required that are required for driving via the subsequent gear shift stage. The term "switching" means that a clutch is closed to also direct the power path over the already inserted connections.

Object of the present invention is to provide a dual-clutch transmission of the type mentioned above, which realizes the highest possible number of gears in a small space, with no or only a small number of support circuits in the gearshift sequence are required.

The object is achieved by a transmission for motor vehicles which is switchable between a plurality of gear shift stages and has four degrees of freedom, wherein one of the degrees of freedom is a first input, one of the degrees of freedom is a second input, one of the degrees of freedom is an output and one of the degrees of freedom is an intermediate degree , Between the first input and the intermediate degree of freedom, at least two switchable connections that can be used for forward gears are provided. Between the Zwischenfreiheitsgrad and the output at least two usable for forward gears, switchable connections are provided. Between the second input and the output are at least two usable for forward gears, switchable connections provided and between the second input and the intermediate degree of freedom at least one usable for a forward gear, switchable connection is provided. In contrast to the transmissions described in the prior art, the transmission according to the invention has a total of four degrees of freedom, wherein one degree of freedom comprises all components of a gear set, z. As shafts and gears that are drivingly connected to each other without the operation of switching elements and thus rotate together. In this case, an intermediate degree of freedom is provided, the components of which are not drive-connected to one of the inputs or to the output without actuation or closing of a switching element. Here, the two inputs with the intermediate degree of freedom are either drive-connected. At least two direct connections are provided between the second input and the output. This arrangement of links and degrees of freedom allows three gear ratios to be provided in the low-speed to high-speed gearshift sequence following a direct gearshift stage between the second input and the output, always shifting from one input to the other in the gearshift sequence becomes. The term "direct" gear shift stage refers to gear shift stages in which the power path is routed directly from one of the inputs, in this case the second input, via a connection to the output and no further degree of freedom is interposed. where the power path leads over at least three degrees of freedom. In the transmission according to the invention thus a gear shift sequence with nine or more gear shift stages (gears) is possible in which no support circuit is required, ie in which can be blended in principle between two successive courses of an input to the other input. A reverse gear can be realized that between the second input and the intermediate degree of freedom a switchable to realize the reverse gear connection is provided.

Preferably, both inputs are each via a coupling, in particular a Friction clutch, with a prime mover, such as an internal combustion engine, connectable.

The transmission is preferably controlled in such a way that, in the sequence of all successive forward gear shift stages used, the drive takes place alternately via one of the inputs. This avoids that so-called support circuits must be used.

It is preferably provided that the transmission is controlled in such a way that, in at least one group of at least three successive gear shift stages, the power path is always guided via one of the connections of the intermediate degree of freedom to the output.

It can be provided that at least two such groups of at least three successive gear shift stages are provided, between which a gear shift stage is provided, in which the power path is led from the second input via one of the connections between the second input and the output to the output.

Preferred embodiments will be explained in more detail below with reference to the drawings. Herein shows

1 shows a schematic representation of the degrees of freedom of a transmission according to the invention,

FIG. 2 shows a diagram of the switching sequence of the transmission according to FIG. 1,

FIG. 3 shows a schematic representation of a first embodiment of a transmission according to the invention,

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

FIG. 5 shows a schematic representation of a third embodiment of an inventive to the transmission according to the invention,

FIG. 6 shows a schematic illustration of a fourth embodiment of a transmission according to the invention,

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

8 shows a schematic representation of a sixth embodiment of a transmission according to the invention, and the torque curve in the case of a cross-fading switching operation.

1 shows a schematic representation of the transmission according to the invention with four degrees of freedom, namely a first degree of freedom as first input 10, a second degree of freedom as second input 20, a third degree of freedom as intermediate degree of freedom 30 and a fourth degree of freedom as output 40. Each degree of freedom comprises all parts, such as shafts and gears, which are drivingly connected together without the operation or the closing of switching elements and can rotate together or rotate. The individual degrees of freedom 10, 20, 30, 40 can be drive-connected to one another via connections, the connections being switchable. A compound may include switching elements and one or more gears here. Between the first input 10 and the intermediate degree of freedom 30, two connections 11, 12 are provided, which can be selectively switched to drive-connect the first input 10 to the intermediate degree of freedom 30. Furthermore, the connections 11, 12 are switchable such that the first input 10 and the intermediate degree of freedom 30 are not drive-connected to one another, ie no power can be conducted from the first input 10 to the intermediate degree of freedom 30. Between the intermediate degree of freedom 30 and the output 40, two connections X1, X2 are also provided, which are selectively switchable in order to drive-connect the intermediate degree of freedom 30 to the output 40 or which can be switched such that the intermediate degree of freedom 30 is not connected to the output 40. is connected to the drive. Between the second input 20 and the output 40, two switchable connections II, VI are also provided, which can be selectively switched to drive-connect the second input 20 to the output 40 or which can be switched such that the second input 20 and the output 40 are not drive-connected. Between the second input 20 and the intermediate degree of freedom 30 further two switchable connections 111, R are provided which are selectively switchable to drive connect the second input 20 to the intermediate degree of freedom 30 or switched such that the second input 20 does not interfere with the intermediate degree of freedom 30 is drive-connected. The connection R also causes a reversal of direction to ensure a reverse gear. All other connections 11, 12, 111, X1, X2, II, VI serve to realize forward gears, provided that the connection R is not arranged in the power path. Preferably, the connections are switched such that each pair of connections between two degrees of freedom 10, 20, 30, 40 is switchable by means of a common shift fork. Thus, a total of four shift forks are required.

The first input 10 is also connectable via a first clutch C1 with a drive motor, not shown here. The second input 20 is connectable via a second clutch C2 with the same drive motor.

Figure 2 shows a schematic of the switching sequences for different gear shift stages (gears). For each gear shift stage is indicated, via which clutch C1, C2 is driven. For this purpose, the respective line indicates via which connection the power path runs.

In the first gear (gear shift stage 1), therefore, the first clutch C1 is used for driving, the power path via the first connection 11 between the first input 10 and the intermediate degree of freedom 30, the first connection 111 between the intermediate degree of freedom 30 and the second input 20 and first connection II between the second input 20 and the output 40 extends.

When switching to second gear (gear shift level 2) can be dazzled directly become the second clutch C2. There, the power path from the second input 20 via the first connection II between the second input 20 and the output 40 to the output 40. In the third gear (gear shift stage 3) is blended again to the first clutch C1, the power path from the first input 10 via the first connection 11 between the first input 10 and the intermediate degree of freedom 30 to the intermediate degree of freedom 30 and from there via the first connection X1 between the intermediate degree of freedom 30 and the output 40 to the output 40 extends.

The fourth gear (gear shift stage 4) is superimposed to the second clutch C2, wherein the power path from the second input 20 via the first connection 111 between the intermediate degree of freedom 30 and the second input 20 to the intermediate degree of freedom 30 and from there via the connection between the intermediate degree of freedom X1 30 and the output 40 leads to the output 40.

After fading to the first clutch C1 to achieve the fifth gear (gear shift stage 5), the power path from the first input 10 via the second connection 12 between the first input 10 and the intermediate degree of freedom 30 to the intermediate degree of freedom 30 and from there via the first connection X1 between the intermediate degree of freedom 30 and the output 40 to the output 40 passed.

From fifth gear is in the sixth gear (gear shift stage 6) blended to the second clutch C2, the power path from the second input 20 via the second connection VI between the second input 20 and the output 40 to the output 40 leads.

In the seventh gear (gear shift stage 7) is blended to the first clutch C1, the power path from the second input 20 via the first connection 11 between the first input 10 and the intermediate degree of freedom 30 to the intermediate degree of freedom 30 and from there via the second connection between the intermediate degree of freedom X 30th and the output 40 to the output 40.

From seventh gear to eighth gear (gear shift stage 8) to the second gearshift clutch C2, wherein the power path from the second input 20 via the first connection 111 between the intermediate degree of freedom 30 and the second input 20 to the intermediate degree of freedom 30 and from there via the second connection X2 between the intermediate degree of freedom 30 and the output 40 to the output 40.

In the ninth gear (gear shift stage 9) is blended to the first clutch C1, wherein the power path from the second input 20 via the second connection 12 between the first input 10 and the intermediate degree of freedom 30 to the intermediate degree of freedom 30 and from there via the second connection between the intermediate degree of freedom X2 30 and the output 40 to the output 40 runs.

A reverse gear (gear shift stage R) can be achieved that via the first clutch C1, the power path from the first input 10 via the first connection 11 between the first input 10 and the intermediate degree of freedom 30 to the intermediate degree of freedom 30 and from there via the second connection R between the Intermediate degree of freedom 30 and the second input 20 to the second input 20 and further via the first connection II between the second input 20 and the output 40 to the output 40 extends. Of course, further combinations are possible for the realization of further reverse gears, as long as the second connection R is connected between the intermediate degree of freedom 30 and the second input 20.

FIG. 3 shows a first embodiment of a wheel arrangement of a transmission according to the invention. The first input 10 comprises a first input shaft 1 1, which is drive-connected via a first clutch C1 with a drive motor, not shown, usually an internal combustion engine of a motor vehicle. The first clutch C1 is designed as a friction clutch, wherein to simplify the present schematic illustration, the first clutch C1 is shown only with a first coupling element, which is part of the first input 10.

The intermediate degree of freedom 30 comprises an intermediate shaft 31, which is arranged rotatable parallel to the first input shaft 1 1. On the intermediate shaft 31 is a first Fixed wheel 32 and a second fixed wheel 33 is arranged. The two fixed wheels 32, 33 are fixedly connected to the intermediate shaft 31 and run with this. The first fixed gear 32 meshes with a first idler gear 34 which is rotatably mounted on the first input shaft 1 1. The second fixed gear 33 meshes with a second idler gear 35, which is likewise rotatably arranged on the first input shaft 1 1. Via a first switching arrangement A, which is part of the first input 10, the first idler gear 34 and the second idler gear 35 can optionally be connected in a rotationally fixed manner to the first input shaft 1 1. In a middle position of the first switching arrangement A, neither of the two idler gears 34, 35 is non-rotatably connected to the first input shaft 1 1. The first idler gear 34 and the second idler gear 35 can thus rotate relative to the first input shaft 1 1. The first idler gear 34 and the first switching arrangement A are part of the first connection 11 between the first input 10 and the intermediate degree of freedom 30. The second idler gear 35 and the switching arrangement A are part of the second connection 12 between the first input 10 and the intermediate degree of freedom 30. Das The first idler gear 34 meshes with a third idler gear 36. The second idler gear 35 meshes with a fourth idler gear 37. The third idler gear 36 and the fourth idler gear 37 are arranged parallel to the first input shaft 1 1 and parallel to the intermediate shaft 31 rotatable. The intermediate shaft 31, the fixed wheels 32, 33 and the loose wheels 34, 35, 36, 37 are part of the intermediate degree of freedom 30.

The output 40 comprises an output shaft 41 on which an output gear 42 is arranged, which is connectable to a drive arrangement for driving wheels of a motor vehicle, in particular with a differential gear. The third idler gear 36 and the fourth idler gear 37 of the intermediate degree of freedom 30 are rotatably arranged on the output shaft 41. Via a third switching arrangement C, the output shaft 41 can optionally be connected in a rotationally fixed manner to the third idler gear 36 or the fourth idler gear 37. In an intermediate position of the third shift arrangement C, neither of the two idler gears 36, 37 is drive-connected to the output shaft 41, so that the third idler gear 36 and the fourth idler gear 37 are freely rotatable on the output shaft 41. The third idler gear 36 and the third shifting arrangement C are thus part of the first connection X1 between the intermediate degree of freedom 30 and the output 40. The fourth idler gear 37 and the third shifting arrangement C form part of the second connection X2 between the intermediate degree of freedom 30 and the output 40th

The second input 20 includes a second input shaft 21, which is connectable via a second clutch C2 with the drive motor, not shown here. To simplify the illustration, only one switching element of the second clutch C2 is shown, wherein the second clutch C2 is designed as a friction clutch. The illustrated switching element of the second clutch C2 is also part of the second input 20. On the second input shaft 21, a first fixed gear 22 and a second fixed gear 23 are fixed and rotate with the second input shaft 21st The first fixed gear 22 meshes with a first idler gear 24, which is rotatably mounted on the output shaft 41. The second fixed gear 23 meshes with a second idler gear 25, which is also rotatably mounted on the output shaft 41. About a fourth switching arrangement D, the output shaft 41 can optionally be rotatably connected to the first idler gear 24 or the second idler gear 25. In an intermediate position of the fourth shift arrangement D, neither of the two idler gears 24, 25 is drive-connected to the output shaft 41, so that the first idler gear 24 and the second idler gear 25 are freely rotatable on the output shaft 41. The first idler gear 24 and the fourth shifting arrangement D are part of the first connection II between the second input 20 and the output 40. The second idler gear 25 and the fourth shifting arrangement D are part of the second connection VI between the second input 20 and the output 40.

The second fixed gear 23 further meshes with a third idler gear 26 which is rotatably mounted on the intermediate shaft 31. The first fixed gear 22 meshes with the first idler gear 24 with a fourth idler gear 27, which is also rotatably mounted on the intermediate shaft 31. Via a second switching arrangement B, the intermediate shaft 31 can be selectively connected to the third idler gear 26 or the fourth idler gear 27 rotatably. In an intermediate position of the second shift arrangement B, neither the third idler gear 26 nor the fourth idler gear 27 is rotatably connected to the intermediate shaft 31, so that the third idler gear 26 and the fourth idler gear 27 can rotate freely on the intermediate shaft 31. The third loose wheel 26 and the second shift arrangement B are part of the first connection 111 between the second input 20 and the intermediate degree of freedom 30. The fourth idler gear 27 and the second shift gear B Arrangement B are part of the second connection R between the second input 20 and the intermediate degree of freedom 30.

The second input shaft 21, the fixed wheels 22, 23, and the idler gears 24, 25, 26, 27 are part of the second input 20th

By switching the individual switching arrangements A, B, C, D, the various gear shift stages according to FIG. 2 can be represented. Figure 4 shows a second embodiment of a gear set of a transmission according to the invention, wherein matching components are provided with the same reference numerals.

The elements of the first input 10 of the second embodiment are identical to the elements of the first input of the first embodiment. The first input 10 comprises a first input shaft 1 1, which is drive-connected via a first clutch C1 with a drive motor, not shown, usually an internal combustion engine of a motor vehicle. The first clutch C1 is designed as a friction clutch, wherein to simplify the present schematic Dar- position, the first clutch C1 is shown only with a first coupling element, which is part of the first input 10.

The elements of the intermediate degree of freedom 30 differ in their arrangement to each other. As in the first embodiment, the first idler gear 34 and the second idler gear 35 are rotatably supported on the first input shaft 1 1 and mesh with the third idler gear 36 and the fourth idler gear 37, which are rotatably mounted on the output shaft 41. In contrast to Figure 3 but not the first idler gear 34 and the second idler gear 35 mesh with the two fixed wheels 32, 33 of the intermediate shaft 31, but the third idler gear 36 and the fourth idler gear 37. About the first switching arrangement A, the first idler gear 34 and the second idler gear 35 selectively connected to the first input shaft 1 1 rotatably. In a middle position of the first switching arrangement A, neither of the two idler gears 34, 35 is non-rotatably connected to the first input shaft 1 1. The first idler gear 34 and the second idler gear 35 can thus rotate relative to the first input shaft 1 1. The first te idler gear 34 and the first switching arrangement A are part of the first connection 11 between the first input 10 and the intermediate degree of freedom 30. The second idler gear 35 and the switching arrangement A are part of the second connection 12 between the first input 10 and the intermediate degree of freedom 30. The intermediate shaft 31, the fixed wheels 32, 33 and the idler gears 34, 35, 36, 37 are part of the intermediate degree of freedom 30th

The output 40 comprises an output shaft 41 on which an output gear 42 is arranged, which is connectable to a drive arrangement for driving wheels of a motor vehicle, in particular with a differential gear. The third idler gear 36 and the fourth idler gear 37 of the intermediate degree of freedom 30 are rotatably arranged on the output shaft 41. Via a third switching arrangement C, the output shaft 41 can optionally be connected in a rotationally fixed manner to the third idler gear 36 or the fourth idler gear 37. In an intermediate position of the third shift arrangement C, neither of the two idler gears 36, 37 is drive-connected to the output shaft 41, so that the third idler gear 36 and the fourth idler gear 37 are freely rotatable on the output shaft 41. The third idler gear 36 and the third shifting arrangement C are thus part of the first connection X1 between the intermediate degree of freedom 30 and the output 40. The fourth idler gear 37 and the third shifting arrangement C form part of the second connection X2 between the intermediate degree of freedom 30 and the output 40.

The elements of the second input 20 are identical to the elements of the second input according to the first embodiment. However, the fixed gears 22, 23 do not mesh with all the loose wheels 24, 25, 26, 27 of the second drive 20. The first fixed gear 22 meshes with the first idler gear 24 on the output shaft 21 and the fourth idler gear 27 on the intermediate shaft 31st The second fixed gear 23 meshes with the second idler gear 25 on the output shaft 41st About a fourth switching arrangement D, the output shaft 41 can optionally be rotatably connected to the first idler gear 24 or the second idler gear 25. In an intermediate position of the fourth shift arrangement D, neither of the two idler gears 24, 25 is drive-connected to the output shaft 41, so that the first idler gear 24 and the second idler gear 25 are freely rotatable on the output shaft 41. The first idler gear 24 and the fourth shifting arrangement D are part of the first connection II between the second input 20 and the output 40. The second idler gear 25 and the fourth switching arrangement D are part of the second connection VI between the second input 20 and the output 40. The second idler gear 25 further meshes with a third idler gear 26 which is rotatably mounted on the intermediate shaft 31 , The first idler gear 24 meshes with the first fixed gear 22 with a fourth idler gear 27, which is also rotatably mounted on the intermediate shaft 31. Via a second switching arrangement B, the intermediate shaft 31 can be selectively connected to the third idler gear 26 or the fourth idler gear 27 rotatably. In an intermediate position of the second shift arrangement B, neither the third idler gear 26 nor the fourth idler gear 27 is rotatably connected to the intermediate shaft 31, so that the third idler gear 26 and the fourth idler gear 27 can rotate freely on the intermediate shaft 31. The third idler gear 26 and the second switching arrangement B are part of the first connection 111 between the second input 20 and the intermediate degree of freedom 30. The fourth idler gear 27 and the second switching arrangement B are part of the second connection R between the second input 20 and the intermediate degree of freedom 30.

The second input shaft 21, the fixed wheels 22, 23, and the idler gears 24, 25, 26, 27 are part of the second input 20th

The first embodiment and the second embodiment illustrate wheelset layouts for transversely mounted gear assemblies. The following embodiments, on the other hand, illustrate gear set layouts for longitudinally mounted gear assemblies. Corresponding components and elements are provided below with the same reference numerals used to the first embodiment and the second embodiment were.

The first input 10 of the third embodiment according to FIG. 5 comprises a first input shaft 1 1, which can be drive-connected via a first clutch C1 to a drive motor (not shown), as a rule an internal combustion engine of a motor vehicle. The first clutch C1 is designed as a friction clutch, wherein for simplification of the present schematic illustration, the first clutch C1 is shown only with a first coupling element, which Be is part of the first input 10. The first fixed gear 12 meshes with a first idler gear 14, the second fixed gear 13 meshes with a second idler gear 15, wherein the two idler gears 14, 15 parallel to the first input shaft. 1 1 are rotatably arranged. The first input shaft 1 1, the fixed wheels 12, 13 and the idler gears 14, 15 are elements of the first input 10th

The intermediate degree of freedom 30 comprises an intermediate shaft 31 about which the two loose wheels 14, 15 of the first input 10 are rotatably arranged. The intermediate shaft 31 carries a first fixed wheel 32. Coaxially with the intermediate shaft 31, a first idler gear 34 is rotatably arranged. The first idler gear 32 meshes with a second idler gear 35. The first idler gear 34 meshes with a third idler gear 36. Here, the second idler gear 35 and the third idler gear 36 are rotatably connected to each other and are arranged together in rotation parallel to the intermediate shaft 31. The intermediate shaft 31, the first fixed gear 32 and the loose wheels 34, 35, 36 are part of the intermediate degree of freedom 30th

The second input 20 includes a second input shaft 21, which is arranged coaxially with the first input shaft 1 1 and which is connectable via a second clutch C2 with the drive motor, not shown here. To simplify the illustration, only one switching element of the second clutch C2 is shown, wherein the second clutch C2 is designed as a friction clutch. The illustrated switching element of the second clutch C2 is also part of the second input 20. On the second input shaft 21 are four fixed wheels, lend a first fixed wheel 22, a second fixed gear 23, a third fixed gear 28 and a fourth fixed gear 29. The first fixed 22 meshes with a first idler gear 24, which is arranged coaxially with the intermediate shaft 31 of the intermediate degree of freedom 30 rotatably. The second fixed gear 23 meshes with a second idler gear 25 which is also rotatably arranged coaxially with the intermediate shaft 31 of the intermediate degree of freedom 30. The third fixed gear 28 meshes with a third idler gear 26, which is also arranged coaxially rotatable with the intermediate shaft 31 of the intermediate degree of freedom. The fourth fixed gear 29 meshes via a not shown here wheel with a fourth idler gear 27, which is also arranged coaxially to the intermediate shaft 31 of the intermediate degree of freedom 30 rotatably. The second input shaft 21, the fixed wheels 22, 23, 28, 29th as well as the loose wheels 24, 25, 26, 27 are elements of the second input 20th

Coaxially to the intermediate shaft 31 of the intermediate degree of freedom 30, an output shaft 41 is rotatably mounted, which is rotatably connected to an output gear 42, which is connectable to a drive assembly for driving wheels of a motor vehicle, in particular with a differential gear.

By way of a shift arrangement A, either the first idler gear 14 or the second idler gear 15 of the first input 10 can be non-rotatably connected to the intermediate shaft 31 or switched such that neither of the idler gears 14, 15 is connected to the intermediate shaft 31. The switching arrangement A and the first idler gear 14 are part of the first connection 11 between the first input 10 and the intermediate degree of freedom 30. The second idler gear 15 and the switching arrangement A are part of the second connection 12 between the first input 10 and the intermediate degree of freedom 30th

By way of a second shift arrangement B, optionally the third idler gear 26 or the fourth idler gear 27 of the second input 20 can be connected to the intermediate shaft 31 of the intermediate degree of freedom 30. Furthermore, the second switching arrangement B is switchable such that neither the third idler gear 26 nor the fourth idler gear 27 is drive-connected to the intermediate shaft 31. The third idler gear 26 and the second switching arrangement B are part of the first connection 111 between the second input 20 and the intermediate degree of freedom 30. The fourth idler gear 27 and the second switching arrangement B are part of the second connection R between the second input 20 and the intermediate degree of freedom 30.

By way of a third shift arrangement C, optionally the first fixed wheel 32, and thus the intermediate shaft 31, the intermediate degree of freedom 30 or the first idler gear 34 of the intermediate degree of freedom 30, can be connected in a rotationally fixed manner to the output shaft 41. In an intermediate position of the third shift arrangement C, neither the first fixed wheel 32 nor the first idler gear 34 is connected to the output shaft 41. The first fixed gear 32 and the third shifting arrangement C are part of the first connection X1 between the intermediate degree of freedom 30 and the output 40. The first idler gear 34 and the third shifting arrangement C are part of the second connection X2 between the Intermediate degree of freedom 30 and the output 40.

Via a fourth shift arrangement D, either the first idler gear 24 or the second idler gear 25 of the second input 20 can be connected to the output shaft 41. In an intermediate position, neither the first idler gear 24 nor the second idler gear 25 is connected to the output shaft 41. The first idler gear 24 and the fourth shifting arrangement D are elements of the first connection II between the second input 20 and the output 40. The second idler gear 25 and the fourth switching arrangement D are elements of the second connection VI between the second input 20 and the output 40.

The first input 10 of the fourth embodiment according to FIG. 6 comprises a first input shaft 1 1, which can be drive-connected via a first clutch C1 to a drive motor (not shown), as a rule an internal combustion engine of a motor vehicle. The first clutch C1 is designed as a friction clutch, wherein to simplify the present schematic illustration, the first clutch C1 is shown only with a first coupling element, which is part of the first input 10. The first fixed gear 12 meshes with a first idler gear 14, the second fixed gear 13 meshes with a second idler gear 15, wherein the two idler gears 14, 15 parallel to the first input shaft 1 1 are rotatably arranged. The first input shaft 1 1, the fixed wheels 12, 13 and the idler gears 14, 15 are elements of the first input 10. The intermediate degree of freedom 30 comprises an intermediate shaft 31 about which the two loose wheels 14, 15 of the first input 10 are rotatably arranged. The intermediate shaft 31 carries a first fixed gear 32. Coaxially to the intermediate shaft 31, a first idler gear 34 is rotatably arranged. The first idler gear 32 meshes with a second idler gear 35. The first idler gear 34 meshes with a third idler gear 36. Here, the second idler gear 35 and the third idler gear 36 are connected to each other in a rotationally fixed manner and are rotatably arranged together parallel to the intermediate shaft 31. On the intermediate shaft 31, a second fixed wheel 33 is further provided that meshes via a not-shown wheel with a fourth idler gear 37 that is coaxial with the idler gears 35, 36 rotatably arranged. The intermediate shaft 31, the fixed wheels 32, 33 and the idler gears 34, 35, 36, 37 are part of the intermediate degree of freedom 30.

The second input 20 includes a second input shaft 21, which is arranged coaxially with the first input shaft 1 1 and which is connectable via a second clutch C2 with the drive motor, not shown here. To simplify the illustration, only one switching element of the second clutch C2 is shown, wherein the second clutch C2 is designed as a friction clutch. The illustrated switching element of the second clutch C2 is also part of the second input 20. On the second input shaft 21 are seated two fixed gears, namely a first fixed wheel 22 and a second fixed gear 23. The first fixed gear 22 meshes with a first idler gear 24 which coaxially to the intermediate shaft 31 of the intermediate degree of freedom 30 is rotatably arranged. The second fixed gear 23 meshes with a second idler gear 25 which is also rotatably arranged coaxially with the intermediate shaft 31 of the intermediate degree of freedom 30. The second input shaft 21, the fixed wheels 22, 23 and the loose wheels 24, 25 are elements of the second input 20.

Coaxial with the shaft 21 of the intermediate degree of freedom 30, an output shaft 41 is rotatably mounted, which is non-rotatably connected to an output gear 42, which is connectable to a drive arrangement for driving wheels of a motor vehicle, in particular with a differential gear.

By way of a shift arrangement A, either the first idler gear 14 or the second idler gear 15 of the first input 10 can be non-rotatably connected to the intermediate shaft 31 or switched such that neither of the idler gears 14, 15 is connected to the intermediate shaft 31. The switching arrangement A and the first idler gear 14 are part of the first connection 11 between the first input 10 and the intermediate degree of freedom 30. The second idler gear 15 and the switching arrangement A are part of the second connection 12 between the first input 10 and the intermediate degree of freedom 30th

Via a second switching arrangement B, the second idler gear 35 of the intermediate degree of freedom 30 or the fourth idler gear 37 of the intermediate degree of freedom 30 can optionally be connected to the second input shaft 21. Further, the second switching arrangement B is switchable such that neither the second idler gear 35 nor the fourth idler gear 37 of the Intermediate degree of freedom 30 is drivingly connected to the second input shaft 21. The second idler gear 35 of the intermediate degree of freedom 30 and the second switching arrangement B are part of the first connection 111 between the second input 20 and the intermediate degree of freedom 30. The fourth idler gear 37 of the intermediate degree of freedom 30 and the second switching arrangement B are part of the second connection R between the second input 20 and the intermediate degree of freedom 30.

By way of a third shift arrangement C, optionally the first fixed wheel 32, and thus the intermediate shaft 31, the intermediate degree of freedom 30 or the first idler gear 34 of the intermediate degree of freedom 30, can be connected in a rotationally fixed manner to the output shaft 41. In an intermediate position of the third shift arrangement C, neither the first fixed wheel 32 nor the first idler gear 34 is connected to the output shaft 41. The first idler gear 34 and the third shifting arrangement C are part of the first connection X1 between the intermediate degree of freedom 30 and the output 40. The first fixed gear 32 and the third shifting arrangement C form part of the second connection X2 between the intermediate degree of freedom 30 and the output 40.

Via a fourth shift arrangement D, either the first idler gear 24 or the second idler gear 25 of the second input 20 can be connected to the output shaft 41. In an intermediate position, neither the first idler gear 24 nor the second idler gear 25 is connected to the output shaft 41. The first idler gear 24 of the second input 20 and the fourth shifting arrangement D are elements of the first connection II between the second input 20 and the output 40. The second idler gear 25 of the second input 20 and the fourth switching arrangement D are elements of the second connection VI between the second input 20 and the output 40th

The first input 10 of the fifth embodiment according to FIG. 7 comprises a first input shaft 1 1, which can be drive-connected via a first clutch C1 to a drive motor (not shown), as a rule an internal combustion engine of a motor vehicle. The first clutch C1 is designed as a friction clutch, wherein to simplify the present schematic illustration, the first clutch C1 is shown only with a first coupling element, which is part of the first input 10. The intermediate degree of freedom 30 comprises a first intermediate shaft 31, which carries three fixed wheels, namely a first fixed gear 32, a fourth fixed gear 38 and a fifth fixed gear 39. Coaxially to the first intermediate shaft 31, a second intermediate shaft 31 'is rotatably mounted, which carries two fixed wheels, namely a second fixed wheel 33 and a third fixed wheel 34 '. The fourth fixed gear 38 meshes with a fifth idler gear 38 'which is rotatably disposed about the first input shaft 1 1. The fifth fixed gear 39 meshes with a sixth idler gear 39 ', which is also rotatably disposed about the first input shaft 1 1. The first fixed gear 32 meshes with a second idler gear 35 and the third fixed gear 34 'with a third idler gear 36. Here, the second idler gear 35 and the third idler gear 36 are rotatably connected to each other and are rotatable together in parallel to the intermediate shafts 31, 31' arranged. The second fixed gear 33 on the second intermediate shaft 31 'is drivingly connected via a not-shown wheel with a fourth idler gear 37, which is arranged coaxially to the idler gears 35, 36 rotatably.

The intermediate shafts 31, 31 ', the fixed wheels 32, 33, 34', 38, 39 and the loose wheels 35, 36, 37, 38 ', 39' are part of the intermediate degree of freedom 30th

The second input 20 includes a second input shaft 21, which is arranged coaxially with the first input shaft 1 1 and which is connectable via a second clutch C2 with the drive motor, not shown here. To simplify the illustration, only one switching element of the second clutch C2 is shown, wherein the second clutch C2 is designed as a friction clutch. The illustrated switching element of the second clutch C2 is also part of the second input 20. On the second input shaft 21 sitting two fixed wheels, namely a first fixed gear 22 and a second fixed gear 23. The first fixed gear 22 meshes with a first idler gear 24, which coaxial with the Between shafts 31, 31 'of the intermediate degree of freedom 30 is rotatably arranged. The second fixed gear 23 meshes with a second idler gear 25, which is also arranged coaxially to the intermediate shafts 31, 31 'of the intermediate degree of freedom 30 rotatably. The second input shaft 21, the fixed wheels 22, 23 and the idler gears 24, 25 are elements of the second input 20th

Coaxial to the intermediate shafts 31, 31 'of the intermediate degree of freedom 30 is a output shaft 41 rotatably mounted, which is rotatably connected to an output gear 42, which is connectable to a drive arrangement for driving wheels of a motor vehicle, in particular with a differential gear. Via a switching arrangement A can optionally the fifth idler gear 38 'or the sixth idler gear 39' of the intermediate degree of freedom 30 rotatably connected to the first input shaft 1 1 or switched so that none of the two idler gears 38 ', 39' with the first input shaft 1 1 connected is. The switching arrangement A and the fifth idler gear 38 'are part of the first connection 11 between the first input 10 and the intermediate degree of freedom 30. The sixth idler gear 39' and the switching arrangement A are part of the second connection 12 between the first input 10 and the intermediate degree of freedom 30th

The third idler gear 36 of the intermediate degree of freedom 30 or the fourth idler gear 37 of the intermediate degree of freedom 30 can optionally be connected to the second input shaft 21 via a second shift arrangement B. Further, the second switching arrangement B is switchable such that neither the third idler gear 36 nor the fourth idler gear 37 of the intermediate degree of freedom 30 is drive-connected to the second input shaft 21. The third idler gear 36 of the intermediate degree of freedom 30 and the second switching arrangement B are part of the first connection 111 between the second input 20 and the intermediate degree of freedom 30. The fourth idler gear 37 of the intermediate degree of freedom 30 and the second switching arrangement B are part of the second connection R between the second input 20 and the intermediate degree of freedom 30. About a third switching arrangement C are optionally the first fixed gear 32, and thus the first intermediate shaft 31, the intermediate degree of freedom 30 or the third fixed gear 34 ', and thus the second intermediate shaft 31', the intermediate degree of freedom 30 with the output shaft 41st rotatably connected. In an intermediate position of the third shift arrangement C, neither the first fixed wheel 32 nor the third fixed wheel 34 'is connected to the output shaft 41. The first fixed gear 32 and the third shifting arrangement C form part of the first connection X1 between the intermediate degree of freedom 30 and the output 40. The third fixed gear 34 'and the third shifting arrangement C form part of the second connection X2 between the intermediate degree of freedom 30 and the output 40. Via a fourth shift arrangement D, either the first idler gear 24 or the second idler gear 25 of the second input 20 can be connected to the output shaft 41. In an intermediate position, neither the first idler gear 24 nor the second idler gear 25 is connected to the output shaft 41. The first idler gear 24 of the second input 20 and the fourth shifting arrangement D are elements of the first connection II between the second input 20 and the output 40. The second idler gear 25 of the second input 20 and the fourth switching arrangement D are elements of the second connection VI between the second input 20 and the output 40th

The first input 10 of the sixth embodiment according to FIG. 8 comprises a first input shaft 11, which can be drive-connected via a first clutch C1 to a drive motor (not shown), as a rule an internal combustion engine of a motor vehicle. The first clutch C1 is designed as a friction clutch, wherein to simplify the present schematic illustration, the first clutch C1 is shown only with a first coupling element, which is part of the first input 10.

The intermediate degree of freedom 30 comprises an intermediate shaft 31, which carries four fixed wheels, namely a second fixed gear 33, a third fixed gear 34 ', a fourth fixed gear 38 and a fifth fixed gear 39. Coaxially to the intermediate shaft 31, a first idler gear 34 is rotatably mounted. The fourth fixed gear 38 meshes with a fifth idler gear 38 'which is rotatably disposed about the first input shaft 1 1. The fifth fixed gear 39 meshes with a sixth idler gear 39 ', which is arranged rotatably about the first input shaft 1 1. The first idler gear 34 meshes with a second idler gear 35 and the third fixed gear 34 'with a third idler gear 36. Here, the second idler gear 35 and the third idler gear 36 are rotatably connected to each other and are arranged together in rotation parallel to the intermediate shaft 31. The second fixed gear 33 is drivingly connected to the intermediate shaft 31 via a wheel, not shown, with a fourth idler gear 37, which is arranged to be rotatable coaxially with the idler gears 35, 36.

The intermediate shaft 31, the fixed wheels 33, 34 ', 38, 39 and the loose wheels 34, 35, 36, 37, 38', 39 'are part of the intermediate degree of freedom 30th The second input 20 includes a second input shaft 21, which is arranged coaxially with the first input shaft 1 1 and which is connectable via a second clutch C2 with the drive motor, not shown here. To simplify the illustration, only one switching element of the second clutch C2 is shown, wherein the second clutch C2 is designed as a friction clutch. The illustrated switching element of the second clutch C2 is also part of the second input 20. On the second input shaft 21 sitting two fixed wheels, namely a first fixed gear 22 and a second fixed gear 23. The first fixed gear 22 meshes with a first idler gear 24, which coaxial with the intermediate shaft 31 of the intermediate degree of freedom 30 is rotatably arranged. The second fixed gear 23 meshes with a second idler gear 25 which is also rotatably arranged coaxially with the intermediate shaft 31 of the intermediate degree of freedom 30. The second input shaft 21, the fixed gears 22, 23 and the idler gears 24, 25 are elements of the second input 20. Coaxial with the intermediate shafts 31 of the intermediate degree of freedom 30, an output shaft 41 is rotatably mounted, which is rotatably connected to an output gear 42, which with a drive assembly for driving wheels of a motor vehicle is connectable, in particular with a differential gear. Via a switching arrangement A can optionally the fifth idler gear 38 'or the sixth idler gear 39' of the intermediate degree of freedom 30 rotatably connected to the first input shaft 1 1 or switched so that none of the two idler gears 38 ', 39' with the first input shaft 1 1 connected is. The switching arrangement A and the fifth idler gear 38 'of the intermediate degree of freedom 30 are part of the first connection 11 between the first input 10 and the intermediate degree of freedom 30. The sixth idler gear 39' of the intermediate degree of freedom 30 and the switching arrangement A are part of the second connection 12 between the first input 10 and the intermediate degree of freedom 30. Via a second switching arrangement B is optionally the third idler gear 36 of the intermediate degree of freedom 30 or the fourth idler gear 37 of the intermediate degree of freedom 30 with the second input shaft 21 connectable. Further, the second switching arrangement B is switchable such that neither the third idler gear 36 nor the fourth idler gear 37 of the intermediate degree of freedom 30 is drive-connected to the second input shaft 21. The third idler gear 36 of the intermediate degree of freedom 30 and the second switching arrangement B are part of the first connection 111 between the second input 20 and the intermediate degree of freedom 30. The fourth idler gear 37 of the intermediate degree of freedom 30 and the second switching arrangement B are part of the second connection R between see the second Input 20 and the intermediate degree of freedom 30.

Via a third switching arrangement C, either the first idler gear 34 of the intermediate degree of freedom 30 or the third fixed gear 34 'of the intermediate degree of freedom 30 can be connected in a rotationally fixed manner to the output shaft 41. In an intermediate position of the third shift arrangement C, neither the first idler gear 34 nor the third fixed gear 34 'is connected to the output shaft 41. The first idler gear 34 of the intermediate degree of freedom 30 and the third shifting arrangement C form part of the first connection X1 between the intermediate degree of freedom 30 and the output 40. The third fixed wheel 34 'of the intermediate degree of freedom 30 and the third shifting arrangement C form part of the second connection X2 between the intermediate degree of freedom 30 and the output 40.

Via a fourth shift arrangement D, either the first idler gear 24 or the second idler gear 25 of the second input 20 can be connected to the output shaft 41. In an intermediate position, neither the first idler gear 24 nor the second idler gear 25 is connected to the output shaft 41. The first idler gear 24 of the second input 20 and the fourth shifting arrangement D are elements of the first connection II between the second input 20 and the output 40. The second idler gear 25 of the second input 20 and the fourth switching arrangement D are elements of the second connection VI between the second input 20 and the output 40th

In Figure 9, the torque curve of the two clutches C1, C2 is shown simplified over time. During the shift from the first gear shift stage to the second gear shift stage, a "crossfade" from the first shift clutch C1 to the second shift clutch C2 takes place, as is the case with conventional dual clutch transmissions, ie during the continuous opening of the first clutch C1 of the first input clutch the second clutch C2 of the second input is closed continuously, so that there is no interruption in the traction during the shifting process. the second gear shift stage is pre-set, so that it can be "blended over" without an interruption in traction. As the torque on the first shift clutch C1 reduces, the torque on the second shift clutch C2 increases.

LIST OF REFERENCE NUMBERS

A first switching arrangement

B second switching arrangement

C third switching arrangement

D fourth switching arrangement

11 first connection

12 second compound 111 first compound X1 first compound X2 second compound II first compound VI second compound R second compound

10 first entrance

 1 1 first input shaft

12 first fixed wheel

 13 second fixed wheel

14 first idler gear

 15 second idler gear

 20 second input

21 second input shaft

22 first fixed wheel

 23 second fixed wheel

24 first idler gear

 25 second idler gear

 26 third idler gear

27 fourth idler gear third fixed wheel fourth fixed wheel

Intermediate degree of freedom, 31 'intermediate shaft

 first fixed gear second fixed gear first idler gear

'third fixed wheel

 second idler gear third idler gear fourth idler gear fourth fixed gear 'fifth idler gear

 fifth fixed gear 'sixth idler gear

 output

output shaft

output gear

Claims

Transmission claims 1 . Transmission for motor vehicles, which is switchable between a plurality of gear shift stages comprising  four degrees of freedom, wherein one of the degrees of freedom is a first input (10), one of the degrees of freedom is a second input (20), one of the degrees of freedom is an output (40) and one of the degrees of freedom is an intermediate degree of freedom (30), at least two selectable for forward gears, switchable Connections (11, 12) between the first input (10) and the intermediate degree of freedom (30), at least two forward gears, switchable connections (X1, X2) between the intermediate degree of freedom (30) and the output (40), at least two for forward speeds usable, switchable connections (II, VI) between the second input (20) and the output (40), and  at least one switchable connection (111, R) which can be used for a forward gear, between the second input (20) and the intermediate degree of freedom (30). 2. Transmission according to claim 1, characterized in that between the second input (20) and the intermediate degree of freedom (30) is provided for realizing a reverse connection switchable connection (R). 3. Transmission according to one of the preceding claims, characterized in that the two inputs (10, 20) in each case via a clutch (C1, C2) are connectable to a prime mover. 4. A method for operating a transmission according to one of the preceding claims, characterized in that the transmission is controlled such that in the sequence of all used successive forward gear shift stages, the drive is alternately via one of the inputs (10, 20). 5. The method according to claim 4, characterized in that the transmission is controlled such that at least one group at least three successive gear shift stages of the power path always via one of the compounds (X1, X2) between the intermediate degree of freedom (30) and the output (40 ) to be led. 6. The method according to claim 5, characterized in that at least two groups of at least three successive gear shift stages are provided according to claim 5, between which a gear shift stage is provided, wherein the power path from the second input (20) via one of the compounds (II, VI) between the second input (20) and the output (40) to the output (40) is guided.