WO2018072893A1 - Dual clutch transmission having a bridge shaft - Google Patents

Abstract

The invention relates to a dual clutch transmission, comprising two input shafts (10, 30), at least one first output shaft (50), and a bridge shaft (90). A torque can be transferred from one of the input shafts (10, 30) to the other input shaft (30, 10) by means of the bridge shaft (90). A gearwheel assembly associated with a reverse gear has a first fixed gear (31), an idler gear (111), and a second bridge free gear (93). The first fixed gear (31), which meshes with the idler gear (111), is free from the meshing engagement of other gears.

Description

 Double clutch transmission with bridge description

The invention relates to a dual-clutch transmission for a motor vehicle, wherein the dual-clutch transmission comprises a first and second input shaft and a first output shaft.

From DE 10 2011 056 517 A1, such a dual-clutch transmission is known. The input shafts are arranged coaxially with each other. A plurality of fixed gears and idler gears serve to transmit a torque introduced into the input shafts by a motor to the first output shaft. The first output shaft is rotatably connected to a first pinion, which can be connected to an output. The dual-clutch transmission has several gears, wherein at an engaged gear torque from an input shaft via a gear associated with the gear, comprising a fixed gear and at least one switchable idler gear, is transmitted to the first output shaft which delivers the torque to the output to the To accelerate motor vehicle, for example, or to keep it at a constant speed.

In addition, the double-clutch transmission of DE 10 2011 056 517 A1 has a coupling or bridge shaft, by means of which torque can be transmitted from one of the input shafts to the other input shaft. On the bridge shaft, which is at a distance from the first output shaft, there is a bridge fixed wheel, which is non-rotatably connected with the bridge shaft. le is connected. In addition, a first Brückenlosrad and a second Brückenlosrad are arranged on the bridge shaft, which can be rotatably connected to the bridge shaft. In a switched state of either the first bridgeless wheel or the second bridgeless wheel, the bridge shaft acts as a torque bridge between the first input shaft and the second input shaft. The first Brückenlosrad serves to provide a forward gear, while the second Brückenlosrad serves to provide a reverse gear.

On the first input shaft sits a first transfer wheel, which meshes with the bridge wheel. A second transfer wheel is disposed on the second input shaft which meshes not only with the first bridge idler wheel but also with a first idler gear on the first output shaft. The second Brückenlosrad meshes with an intermediate on an additional shaft, which meshes with a first fixed gear on the second input shaft. The first fixed gear meshes with another idler gear at the same time. By the intermediate gear on the additional shaft necessary for the reverse gear rotation reversal is realized. Also shows the DE 10 2011 056 517 A1 in another embodiment, the intermediate wheel for the required direction of rotation reversal as an already provided idler gear of another gear of the dual clutch transmission form. Thus, this idler gear on a dual function, namely said direction reversal for the reverse gear and the realization of a forward gear.

The dual-clutch transmission of DE 10 20 1 056 517 A1 is due to its relatively short axial Bauiänge for placement in a motor vehicle with front output transverse to the direction of travel. The space is in a motor vehicle with transversely mounted engine and gearbox not only severely limited in the axial direction, but may also be connected in the radial direction with very specific packaging requirements. On the other hand, the requirements for a motor vehicle with respect to ride comfort and efficiency are constantly increasing, which leads to transmissions with a larger number of gears and thus generally more space for the transmission. When designing the gearbox, it should also be noted that the gear ratios of the individual gears must be coordinated with one another for the purpose of driving comfort, which has an influence on the gear diameter and center distances. Also, the structure of the transmission should be as simple as possible and / or the number of required components as small as possible 7 064589

be to keep the production costs low. Thus, the design of a transmission or in particular its wheelset is a complex task, which is characterized by very different and sometimes conflicting requirements.

The invention is therefore based on the object to provide a dual-clutch transmission for a motor vehicle, in particular for a motor vehicle with front transverse drive, which fulfills the different requirements described above as well as possible.

The object underlying the invention is achieved with the feature combination according to claim 1. Preferred embodiments may be taken from the subclaims.

According to the invention, it is provided that the first fixed wheel, which meshes with the intermediate wheel, is free of a meshing engagement of further gear wheels. The first fixed wheel has only the function of establishing a connection between the second input shaft and the second bridge wheel with the interposition of the intermediate gear. This means that the idler gear is in sole engagement with the first fixed gear and no other gear is in the plane of the first fixed gear and is in meshing engagement therewith. The meshing engagement is understood here as a direct and direct engagement between two gears, without the need for other gears or components such as a chain are necessary. The first fixed wheel thus transmits only a torque for driving the motor vehicle when the reverse gear is engaged.

In a preferred embodiment, the idler gear is disposed on an auxiliary shaft that is spaced from the bridge shaft and the first output shaft. The intermediate wheel can also be a loose wheel, which is preferably arranged on the first output shaft. The idler or idler gear can be limited to the function of reverse rotation for the reverse gear, so except the first fixed gear and the second Brückenlosrad with no other gear in meshing engagement. 9

Since the first fixed wheel in the preferred. Embodiment only with the seated on the additional shaft intermediate wheel meshes, a diameter of the first fixed gear and a diameter of the second Brückenlosrads can be set comparatively freely. The gear ratio of the reverse gear depends, in addition to the ratio of the diameter of the second bridge fixed wheel to the diameter of the first fixed gear, also on the ratio of the diameter of the bridge fixed wheel to a diameter of the first transfer wheel. The latter ratio, however, also has an influence on the transmission ratio of the forward gear, which is provided by the first bridgeless wheel. Since the ratio of diameter second bridges los rad to diameter first fixed gear is relatively freely selectable, there is virtually no dependence on the ratio diameter bridge fixed to diameter first transfer wheel. Thus, the gear ratio of the realized over the first Brückenlosrad forward gear can be chosen relatively freely.

The provision of a separate auxiliary shaft, which serves only to rotatably support the necessary for the rotation reversal intermediate wheel, means a higher number of items compared to a solution in which the required direction of rotation over a sitting on the first output shaft and with the second Bridge wheel meshing idler gear of another gear is done. However, since the requirement of meshing engagement of the idler gear is not given, the position of the bridge shaft with respect to the first output shaft can be selected with more degrees of freedom. This is particularly helpful if there is very little space available near or in the area of the first output shaft.

If, for example, torque is introduced into the second input shaft by an engine of the motor vehicle, this torque can be transmitted to the first bridge wheel via the second transfer wheel, which is preferably configured as a fixed wheel and is non-rotatably mounted on the second input shaft. In this case, when the first Brückenlosrad is in a switched state, ie the Brückenlosrad is non-rotatably connected to the bridge shaft, the torque can be transmitted via the bridge shaft and the bridge fixed to the first transfer wheel, which is also designed as the second transfer preferably as a fixed wheel and rotatably on the first input shaft sits. From the first input shaft, the torque can then be transmitted to the first output shaft via further gear meshing. be led to accelerate the vehicle or to keep it at a constant speed.

When reverse gear is engaged, the torque curve is carried out by the dual clutch transmission of the invention from the second input shaft to the first fixed wheel, via the intermediate wheel to the second Brückenlosrad. When reverse gear is engaged, the second bridgeless wheel is rotatably connected to the bridge shaft, so that the torque is transmitted along the bridge shaft to the bridge fixed. By the meshing engagement with the first transfer wheel, the torque reaches the first input shaft. Via further gear meshes, the torque is then transmitted from the first input shaft to the first output shaft.

In one exemplary embodiment, a first forward gear is assigned a gearwheel assembly, which comprises the bridge fixedwheel, the first bridgewheel and the second transferwheel. When the first forward gear is engaged, therefore, the bridge shaft is used to transmit torque from the second input shaft to the first input shaft when the motor vehicle is driven. The first forward gear is the forward gear, with the transmission in the largest ratio is feasible. When the first forward gear is engaged, the first bridgeless wheel is non-rotatably connected to the bridge shaft.

The first forward gear associated with the composite gear may also include a loose wheel, which may also be part of a second forward gear associated gear group. This means that when inserted first forward gear and engaged second forward gear, a same idler gear each rotatably connected to the wheel carrying this lot is connected. This lot rad combs preferably with a trained as a fixed gear on the first input shaft. The difference between the first engaged forward gear and the second engaged forward gear is that at the first forward speed, the torque applied to the first input shaft is not directly removed from the engine but is directed to the first input shaft via the second input shaft and bridge shaft becomes. A third forward gear may be associated with a gear assembly comprising the first idler gear on the first output shaft and the second transfer wheel on the second input shaft. When engaged third forward gear, the first idler gear is rotatably connected to the first output shaft. Thus, the idler gear of the third forward gear and the first bridge idler gear mesh simultaneously with the second transfer wheel.

In one embodiment of the invention, the first transfer wheel is free from a meshing engagement of other gears. The bridge fixed wheel is thus the only gear which lies in the same plane with the first transfer wheel and is in direct contact with it.

The first input shaft may be formed as an inner shaft or core shaft, wherein the second input shaft may be a hollow shaft. Conversely, the second input shaft may be formed as an inner shaft and the first input shaft as a hollow shaft.

In one embodiment, a bridge Doppelgangschaltkupplung is provided on the bridge shaft through which in a first switching position a rotationally fixed connection between the bridge shaft and the first Brückenlosrad and in a second switching position, a rotationally fixed connection between the bridge shaft and the second Brückenlosrad be produced. The bridge double-gear shift clutch is arranged in the axial direction of the bridge shaft between the first Brückenlosrad and the second Brückenlosrad. In principle, it is also possible that two Einzelgangschaltkupplungen are provided on the bridge shaft to switch the first Brückenlosrad and the second Brückenlosrad. Preferably, the second switching position is in the direction of a clutch or motor side of the dual-clutch transmission.

The bridge fixed wheel and the second bridgeless wheel may constitute external gears on the bridge shaft. This means that the bridge shaft carries only further gears, such as the second bridge wheel, between the bridge fixed wheel and the second bridgeless wheel. In one embodiment, the bridge shaft carries exactly three gears, namely the bridgewheel and the two bridge wheels. In addition, no other gears are arranged on the bridge shaft through which torque can be transmitted.

Also, the Brückenfestrad and the first Brückenlosrad can represent external gears on the bridge shaft, in which case in a particular embodiment, the number of arranged on the bridge shaft gears is exactly three.

It may be provided a second output shaft on which a second rotationally fixed pinion is arranged. The second pinion is engaged with the output. For example, the output may have a ring gear, which is respectively in meshing engagement with the first pinion and the second pinion. Accordingly, the first pinion and the second pinion are in the plane of the ring gear. Through various gear combinations, the torque can be transmitted from one of the input shafts to the second output shaft.

A diameter of the second pinion of the second output shaft may be equal to or different from a diameter of the first pinion of the first output shaft. The diameter of the second pinion can be greater or smaller than the diameter of the first pinion. Preferably, the diameter of the first pinion is more than 15%, preferably between 20% and 30% smaller than the diameter of the second pinion.

In one embodiment, only fixed wheels are arranged on the first input shaft. It can also be arranged on the second input shaft only fixed wheels. All idler gears of the dual-clutch transmission can be arranged on the first output shaft, the second output shaft or the bridge shaft. In other words, thus the two input shafts are free of loose wheels.

On the first output shaft, a first double-speed clutch and a second double-speed clutch can be arranged. The second double-speed clutch can in a first shift position, the idler gear of the third forward gear rotatably connected to the first output shaft. The first double-speed clutch can in a second switching position a rotationally fixed connection between the first Produce output shaft and the idler gear, which is part of the gear assembly of the first forward gear and the second forward gear.

A third dual-speed clutch and a single-speed clutch may be disposed on the second output shaft. With the third Doppefgangschaltkupplung can be two idler gears on the second output shaft, which are preferably each associated with a forward gear, rotatably connect to the second output shaft. Another idler gear on the second output shaft, which is preferably associated with a further forward gear, can be connected in a rotationally fixed manner to the second output shaft via the single-gear clutch.

An axial distance between the first input shaft (or the second input shaft) and the second output shaft is greater than an axial distance between the first input shaft and the first output shaft in one embodiment. An axial distance between the bridge shaft and the first input shaft may each be smaller than the axial distances of the first input shaft to the two output shafts.

Reference to the embodiment shown in the drawings, the invention is explained in detail. Show in:

FIG. 1 shows a wheel set of a dual-clutch transmission according to the invention; Figure 2 is a side view of the dual clutch transmission according to the invention; Figure 3 is a section along the line A-A in Figure 2; and FIG. 4 shows a section along the line B-B in FIG. 2.

Figure 1 shows schematically a wheel of a dual clutch transmission, which cooperates in use with an engine M (for example, an internal combustion engine) of a motor vehicle. The dual clutch transmission has a first input shaft labeled 10 and a second input shaft 30. The first input shaft 10 and the second input shaft 30 are arranged coaxially with each other, wherein the first input shaft 10 as the inner shaft and the second output shaft 30 as a hollow shaft are formed. Via a clutch K1 can be the first input shaft 10 rotatably connected to the motor M of the motor vehicle. A second clutch K2 serves for the rotationally fixed connection of the motor M to the second input shaft 30.

Parallel to the input shafts 10, 30 extends a first output field 50, which carries a first pinion 51 at a motor-side end. The first pinion 51 is in the insert position of the dual-clutch transmission in engagement with a ring gear, not shown in Figure 1 of a differential. The DifferenziaJ or the differential downstream wheels drive shafts are parts of a drive of the motor vehicle.

In addition, the dual-clutch transmission has a second output shaft 70 which extends parallel to the input shafts 10, 30 and to the first output shaft 50. At a motor end, the second output shaft 70 has a second pinion 71. The ring gear is thus in meshing engagement with both the first pinion 51 and the second pinion 71.

Furthermore, a bridge shaft 90 is provided, which extends parallel to the remaining shafts 10 to 70. As will be explained later, the bridge shaft 90 serves to transmit torque from the second input shaft 30 to the first input shaft 10. The bridge shaft 90 has the function of a torque bridge between the input shafts 10, 30. On the bridge shaft 90, a bridge fixed wheel 91 is arranged on a side remote from the motor M end. In a central axial position sits on the bridge shaft 90, a first Brückenlosrad 92. At the opposite axial end of the bridge shaft 90, a second Brückenlosrad 93 is provided. The first Brückenlosrad 92 and the second Brückenlosrad 93 can be non-rotatably connected to the bridge shaft 90 via a bridge double-gearshift clutch 94. In a first switching position of the bridge double-gear shift clutch 94, the first bridge gear wheel 92 is connected to the bridge shaft 90. In a second switching position of the bridge double-gear clutch 94, the second bridge gear 93 is non-rotatably connected to the bridge shaft 90. In a neutral position of the bridge Doppelgangschaltkupplung neither the first Brückenlosrad 92 nor the second Brückenlosrad 93 is rotatably connected to the bridge shaft 90. Beyond the gears 91, 92, 93 and the bridge double-gear shift clutch 94, on the bridge shaft le 90 no further components provided by the torque can be absorbed, delivered or forwarded.

The first input shaft 10 carries a first transfer wheel 11 which is in meshing engagement with the bridge fixed gear 91. The meshing engagement is symbolized in FIG. 1 by the dotted line between transfer wheel 11 and bridgework 91. The first transfer wheel 11 is designed as a fixed wheel. Furthermore, there are four other fixed wheels 12, 13, 14 and 15 on the first input shaft 10. Also on the second input shafts 30 only fixed wheels are arranged. These are a first fixed wheel 31, a second transfer wheel 32 and two further fixed wheels 33 and 34. The second transfer wheel 32 is in meshing engagement with the first bridge wheel 92.

The first output shaft 50 carries a first idler gear 52 and three other idler gears 53, 54 and 55, which are each part of a gear group, which can be assigned to a forward gear of the dual clutch transmission. Put simply, the idler gears can be assigned corresponding forward gears. For example, the first idler gear 52 arranged on the first output shaft 50 is also identified by the number 3. The number 3 stands here for a third forward gear, which can be realized with the help of the idler gear 52. The idler gear 54, which can be assigned to a sixth forward gear (see FIG. 6), is arranged at an end of the first output shaft 50 facing away from a motor M. At the opposite end, ie at the end facing the motor M, there is the idler gear 55 for the seventh forward gear.

For the rotationally fixed connection of the loose wheels 54, 53, 52 and 55, a first double-gear shift clutch 56 and a third double-gear clutch 57 are provided. By operating the first Doppelgangschaitkupplung 56, which is located further away from the engine M in the axial direction than the second Doppelgangschaitkupplung 57 can be the sixth forward gear and a second forward gear (see idler gear 53) insert. The idler gear 53 must also, as will be explained in more detail below, also be connected in a rotationally fixed manner to the second output shaft 50 even if an engaged first forward gear and an engaged reverse gear. Accordingly, the idler gear 53 is also marked with the characters 1, 2 and R. The second double-gear Clutch 57 is located approximately in the same plane as the bridge double-gearshift clutch 94.

On the second output shaft 70 a plurality of idler gears are arranged, which can also be assigned to a forward gear of the dual-clutch transmission. For example, a idler gear 72 arranged at an end of the first output shaft 70 facing away from the motor M can be assigned a fourth forward gear. Other idler gears on the second output shaft 70 are denoted by 73 and 74. The idler gear 73 can be assigned to a forward gear eighth and further in the direction of engine M arranged idler gear 74 a fifth forward gear. Between the idler gear 74 and the second pinion 71, a parking P may be arranged.

For the rotationally fixed connection of the idler gear 72 and the idler gear 73 with the second output shaft 70, a third double-gear clutch 75 is provided. The third double-gear shift clutch 75 can assume a first shift position for the rotationally fixed connection of the idler gear 72 and a second shift position for the rotationally fixed connection of the idler gear 73. For the rotationally fixed connection of the idler gear 54 to the second output shaft 70 (fifth forward gear), a single-speed clutch 76 is provided.

The second Brückenlosrad 93, which is additionally marked with R, serves to realize the reverse gear of the dual-clutch transmission. The direction of rotation reversal required for the reverse gear is provided by an intermediate gear 111 which is arranged on a supplementary shaft 110. The auxiliary shaft 110 carries except the idler 111 no further gear or the like for torque transmission. The auxiliary shaft 110 extends parallel to the other shafts 10, 30, 50 and 70. A meshing engagement of the intermediate gear 111 with the first fixed gear 31 is again shown in FIG. 1 by a dotted line.

When reverse gear is engaged, the bridge Doppelgangschaltkupplung 94 is in the second Schaltsteliung, through which a rotationally fixed connection between the second Brückenlosrad 93 and the bridge shaft 90 is given. Starting from the engine M and with engaged reverse gear R and clutch K2 is the Torque transmission from the second input shaft 30 to the first fixed gear 31 and via the intermediate 111 to the second Brückenlosrad 93. The torque flux continues along the bridge shaft 90 to the bridge fixed 91, from which the torque via the first transfer wheel 11 to the first input shaft 10 and thus also on the immediately adjacent to the transfer wheel 11 arranged fixed gear 14 with the idler gear 53 passes. To transmit the torque to the first output shaft 50, the first double-gearshift clutch 56 must be in a second shift position (a shift sleeve of the dual-gearshift clutch 56 is displaced in the direction of engine M). Thus, via the first output shaft 50 and the second pinion 51 of the output can be driven. For the realization of the reverse gear thus two gearshift clutches must be switched simultaneously, namely the bridge Doppelgangschaltkupplung 94 and the first Doppelgangschaltkupplung 56 on the first output shaft 50. Since the first fixed wheel 31 has a smaller diameter than the first transfer wheel 11, the torque transmission from the second Input shaft 30 connected to the first input shaft 10, starting from the first fixed gear 31 with a certain transfer ratio.

The fixed gears on the first input shafts 10 are in meshing engagement with only one idler gear of the dual-clutch transmission. This also applies to the fixed wheel 33 on the second input shaft. The second transfer wheel 32 is the only fixed gear on the second input shafts 10, 30 which simultaneously meshes with two idler gears, namely the first idler gear 52 and the first idler gear 92. The first fixed gear 31 on the second input shaft 30 does not mesh with a loose wheel, but only with the intermediate gear 111, which, however, meshes with the second bridge gear 93.

When the first forward gear is engaged, the torque flux from the second input shaft 30 extends via the second transfer wheel 32 to the first bridge gear wheel 92. The first shift position of the bridge gear shift clutch 94 rotatably connects the bridge gear wheel 92 to the bridge shaft 90. As with the reverse gear R, the torque is then transmitted to the first output shaft 50 via the gears 91, 11, 14, 53.

When the second forward gear is engaged, the bridge double-gearshift clutch 94 is in the neutral position, so that the bridge shaft 90 is in the neutral position. output shaft 30 is decoupled. There is no torque transmission between the input shafts 10, 30 instead. The torque of the motor M passes with the clutch K1 to the fixed gear 14, from there it, as in the first forward gear and in reverse, via the switched idler gear 53 to the first output shaft 50 passes. Although the bridge shaft 90 rotates with the meshing engagement of the gears 11, 91, this is, as already explained above, decoupled from the second input shaft 30 when the second forward gear is engaged. The gradation between the transmission ratio of the first forward gear and the transmission ratio of the second transmission ratio can be adjusted by the ratio of the different diameters of the transfer wheels 11, 32.

A gear change from the first forward gear to the second forward gear is possible without interruption of traction. Since in the first forward gear, the torque of the motor M is transmitted through the clutch K2 and in the second gear through the clutch K1, a corresponding overlapping phase of the clutches K1 and K2 can be realized. This also applies to all higher forward gears of the transmission, all of which can be switched without interruption of traction (switching without interruption of traction always refers to adjacent forward gears, for example from 3 to 4, from 4 to 5 or from 8 to 7). The requirement of switching without interruption of traction also determines the count of the forward gears. Possibly, further forward gears can be realized, but due to the lack of load switching capability (shifting without traction interruption between gears with adjacent gear ratios) are not counted.

Figure 2 shows the spatial arrangement of the axes of the individual shafts 10 to 90. In addition, Figure 2 shows the above-mentioned ring gear, which is designated 130. Due to the fact that the reversal of the direction of rotation for the reverse gear is realized by providing an additional shaft 110 for the intermediate gear 111 instead of a loose wheel seated on the first output shaft 50, the spatial arrangement of the bridge shaft 90 can be chosen more freely.

Figure 3 shows a section along the line AA in Figure 2. The line AA is also composed of several straight sections. In FIG. 2, the line A - A in the second output shaft 70 begins with a vertical section which extends up to the axis of FIG second output shaft 70 leads. The next section connects the axis of the second output shaft 70 with the axis of the coaxial input shafts 10, 30. From there, the line AA continues to the axis of the first output shaft 50 and then to the axis of the ring gear 130. Accordingly, FIG. 3 does not show the bridge shaft 90 and the auxiliary shaft 0 with the gears disposed thereon.

Figure 4 shows a section along the line BB in Figure 2. The line BB is also composed of straight sections and starts in Figure 2 above the input shafts 10, 30. The line BB leads to the axis of the input shafts 10, 30, then to the axis The intersection in Figure 4 thus shows only the input shafts 10, 30 (this then twice) and the bridge shaft 90 and the auxiliary shaft 110th From Figure 4, the meshing engagement of the gears 11, 91 and the meshing engagement of the gears 31, 111 become clear, which are indicated in Figure 1 only by the dotted lines.

Reference numeral list first input shaft

 first transfer wheel

 fixed gear

 fixed gear

 fixed gear

 fixed gear

 second input shaft

 first fixed gear second transfer wheel

 fixed gear

 fixed gear

 first output shaft

 first pinion

 first idler gear

 Losrad

 Losrad

 Losrad

 first dual-speed clutch second dual-speed clutch second output shaft

 pinion

 Losrad

 Losrad

 Losrad

 third double-gear shift clutch

Single gear-shifting clutch

 bridge wave

 Brückenfestrad

 first bridge wheel

 second bridge wheel

Bridge double gearshift clutch additional shaft

idler

ring gear

Claims

claims 1. dual-clutch transmission for a motor vehicle,  - With a first input shaft (10) and a second input shaft (30) which are arranged coaxially to each other,  - having a first output shaft (50), wherein the first output shaft (50) is non-rotatably connected to a first pinion (51), wherein the first pinion (51) is engaged with an output,  - having a plurality of switchable gears, wherein a gear is associated with a gear, which comprises a fixed gear and at least one switchable idler gear to a torque of a drive from the first input shaft (10) or the second input shaft (30) to the first output shaft ( 50), - With a first output shaft (50) spaced bridge shaft (90) on which a Brückenfestrad (91), a first switchable Brückenlosrad (92) and a second switchable Brückenlosrad (93) sits, wherein in a switched state of the first Brückenlosrads (92 ) or the second bridgeless wheel (93), the bridge shaft (90) serves as a torque bridge between the first input shaft (10) and the second input shaft (30), and wherein the first bridgeless wheel (92) for providing a forward gear and the second Brückenlosrad ( 93) for providing a reverse gear, wherein on the first input shaft (10) a first transfer wheel (11) and on the second input shaft (30) a second transfer wheel (32) are provided, wherein the first transfer wheel (11) with the bridge fixed ( 91) is in meshing engagement and the second transfer wheel (32) with the first Brückenlosrad (92) and with a first, on the first output shaft (50) arranged idler gear (52) i m is meshing engagement, and wherein the second Brückenlosrad (93) meshes with an intermediate gear (111) which meshes with a first fixed gear (31) on the second Eingansgwelle (30), wherein the with the intermediate gear (111) meshing first fixed wheel ( 31) is free from a meshing engagement of other gears. Dual-clutch transmission according to claim 1, characterized in that a first forward gear is associated with a gear assembly comprising the Brückenfestrad (91), the first Brückenlosrad (92) and the second transfer wheel (32). Dual-clutch transmission according to claim 2, characterized in that the first forward gear associated gear assembly comprises a further idler gear (53) which is also a part of a second forward gear associated gear group. Dual-clutch transmission according to one of claims 1 to 3, characterized in that a third forward gear is associated with a gear assembly comprising a first idler gear (52) and the second transfer wheel (32) on the second input shaft (30). Dual-clutch transmission according to one of claims 1 to 4, characterized in that the first transfer wheel (11) is free from a meshing engagement of other gears. Dual-clutch transmission according to one of claims 1 to 5, characterized in that the first input shaft (0) as the inner shaft and the second input shaft (30) is designed as a hollow shaft. Double-clutch transmission according to one of claims 1 to 6, characterized in that a bridge double shift clutch (94) on the bridge shaft (90) is provided, through which in a first switching position, a rotationally fixed connection between the bridge shaft (90) and the first Brückenlosrad (92 ) And in a second switching position, a rotationally fixed connection between the bridge shaft (90) and the first Brückenlosrad (93) can be produced. Dual clutch transmission according to one of claims 1 to 7, characterized in that the bridge fixed wheel (91) and the second Brückenlosrad (93) constitute external gears on the bridge shaft (90). Dual-clutch transmission according to one of claims 1 to 8, characterized in that a second output shaft (70) is provided which is spaced from the first output shaft (50), the bridge shaft (90) and the auxiliary shaft (110) and rotationally fixed with a second pinion (70). 71) engaged with the output. Dual clutch transmission according to one of claims 1 to 9, characterized in that a diameter of the second pinion (71) of the second output shaft (70) is different from a diameter of the first pinion (51) of the first output shaft. Dual-clutch transmission according to one of claims 1 to 10, characterized in that the first input shaft (10) and the second input shaft (30) each carry only fixed wheels. Dual clutch transmission according to one of claims 1 to 11, characterized in that a first double-gear shift clutch (56) and a second double-gear shift clutch (57) on the first output shaft (50) are arranged. Dual-clutch transmission according to one of claims 9 to 12, characterized in that a third double-gearshift clutch (75) and a single-gearshift clutch (76) on the second Ausgangswelie (70) are arranged. Dual-clutch transmission according to one of claims 9 to 13, characterized in that an axial distance between the first input shaft (10) and the second output shaft (70) is greater than an axial distance between the first input shaft (10) and the first output shaft (50).