[001] DUAL CLUTCH TRANSMISSION [002] The present invention pertains to a dual clutch transmission according to the preamble of patent claim 1. [003] [004] Present-day automatic transmissions for a front-transverse arrangement in a motor vehicle comprise either an upstream converter and a downstream, power-shift planetary transmission or a duai clutch transmission. [005] The installation space for this drive train arrangement is so limited that the arrangement of the required elements has to be as compact as possible to produce the transmission ratios. This pertains in particular to the instaUation length of the transmission, since the installation space for a transverse Installation is very limited. Furthermore, the efficiency of the transmission is a very important criterion, whereas due to their configuration, dual clutch transmissions have an advantage over conventional planetary transmissions with regand to power losses due to both tooth friction and clutch plate slip. The reason for this is that in a dual clutch transmission, two gears must be engaged, whereas in a planetary transmission two gears must be engaged and in, addition, planetary transmission losses lessen the efficiency in comparison to a dual clutch transmission. Furthermore, a dual clutch transmission has lower slip losses than a planetary transmission, since in the case of a dual clutch transmission, one disengaging power-shift clutch is provided, in comparison to at least three disengaging power-shift dutches in the planetary transmission. [006] Planetary transmissions in a front-transverse design for passenger vehicles usually have a converter as start-up element and comprise at least two planetary gear sets and at least five power-shift elements, which usually are designed as clutch plates/brakes; as a oile, up to six forward gears and one reverse gear can be Implemented. In this case, the planetary transmission can be positioned either fully coaxialiy to the drive shaft, or as a quasi-group transmission (as a rule, 5-gear transmission) with a primary transmission amanged coaxialiy to the drive shaft and one rear-mounted gear set an^nged on a secondary shaft, [007] A transmission with a planetary design is disclosed In the document EP 0 434 525 B1, which comprises essentially a drive shaft and an output shaft that are arranged parallel to each other, a dual planetary gear set that ie arranged concentric to the output shaft, and five shift elements In the fonn of three clutches and two brakes, whose optional locking in pairs determines the different gear transmission ratios between the drive shaft and the output shaft. In this case, the transmission has a front-mounted gear set and two power paths, so that due to selective, paired engaging of the five shifting elements, six fonA^ard gears can be realized. [008] A design comprising a secondary shaft ts known, for example from JP 2005-23987. In this case, the two gear sets of the primary gear set are an-anged on two parallel shafts and are actuated jointly by means of two spur gear-drives or two chain drives. The Input tonque is applied to the two stated shafts by means of a transmission input shaft actively connected to the two stated shafts by means of a spur gear drive, and the torque is transmitted to the pertinent elements of the planetary gear sets by means of the shifting elements according to the shifting logic. [009] Furthermore, from the prior art a dual clutch transmission with a countershaft gearbox design is known, in which the dual clutch is used as a start¬up and shifting element; In this case, the countershaft gearbox can be positively shifted. [010] From document DE 10 2004 001 278 A1 a dual clutch transmission is known which has two input shafts, two clutches and at least one first and one second drive shaft, whereas the first input shaft can be actively connected to the first clutch and the second input shaft can be actively connected to fie second clutch, and the first drive shaft is positioned below, and the second drive shaft is positioned above, the input shafts^ or vice-versa, and the input shafts and drive shafts have mutually engaged toothed gears and at least two toothed gears form one gear stage. i [Oil] In this case at least one toothed gear of a gear stage is designed as an engaging and/or disengaging loose wheel and the other toothed gear is designed as a fixed wheel; furthermore, each drive shaft has one driven toothbd gear to transfer the torque to the axle drive, whereas to implement the reverse gear, an additional shaft is provided which is designed as a third drive shaft. ! [012] From the prior art dual-clutch transmissions are also known with an outlet- connected planetary transmission, however these are not suitable for & standard drive and also not for a front-transverse an^angement. [013] For example, document EP 1 4?? 441 .A2 discloses a family of multiple gear planetary transmissions with a dual clutch. A transmission df this kind comprises an Input shaft and an output shaft, a first, a second, a third and a fourth planetary gear set, whereas the planetary gear sets each have three elements, whereas a first shaft pennanently connects a first element iof the first planetary gear set to a first element of the second planetary gear set! a second shaft permanently connects a second element of the first planetary geiar set to a second element of the second planetary gear set, a third shaft p^nrianently connects one element of the first or second planetary gear set to a first element of the third planetary gear set and of the output shaft, and whereas a fburth shaft permanently connects a second element of the third planetary gear sfet to a first element of the fourth planetary gear set. Furthermore, a first clutch is Iconnected to the input shaft and a second clutch connects the input shaft to a third element of the third planetary gear set. [0141 The transmissions described In EP 1 422 441 A2 also comprise' a first and a second torque transmission mechanism, such that the torque transmission mechanisms optionally connect elements of the first and of the second planetary gear set to the first clutch. Furthermore, a third and a fourth torque transmission mechanism are provided, these torque transmission mechanisms optionally connect elements of the third planetary gear set to elements of the fourth planetary gear set; a fifth and a sixth torque transmission mechanism also connect operational elements of the first or second planetary gear set to a fixed-housing element whereas a seventh torque transmission mechanism detachabiy connects one element of the fourth planetary gear set to the fixed-housing element. Furthemiore, an eighth torque transmission mechanism is provided which optionally connects one element of the first or the second planetary gear set to the first dutch, or one element of the fourth planetary gear set to the fixed-housing element. [015] Additional dual clutch transmissions with downstream planetary gear transmissions are l>Ivided which connects one intermediate shaft to the output shaft Ab. [066] The an-angement shown in FIG. 3 differs from the an-angement according to FIG. 2 in that the spur gear stage S2 associated with the planetary transmission PG2 is an-anged in the direction of force flow in front of the planetary transmission PG2. jn this case, the planetary transmission PG2 is an^anged on a second axle parallel to the dnVe axle, which connects the output shaft Ab by means of the spur gear stage S3. [067] In the arrangement according to FIG. 4. the difference to the arrangement according to FIG. 2 consists in that the spur gear stage S1 associated with the planetary transmission PG1 is located in the direction of force flow in front of the planetary transmission PG1. In this case the planetary transmission PG1 is located on a second axle parallel to the drive axle which is connected to the output shaft Ab by means of the spur gear stage S3. [068] According to FIG. 5, the spur gear stages S1 and S2 associated with the planetary transmissions are positioned in the direction of force flow in front of the planetary transmissions. In this case, the planetary transmissions can be an^nged either on the same intermediate axle located parallel to the drive axle (see FIGS. 17, 18, 19, 20), or can be an-anged on two different, parallel intermediate axles, as explained based on FIGS. 21, 22, 23 and 24. In the case that two different intermediate axles are provided, as shown In FIG. 6, an additional spur gear stage S4 is required, in order to ensure the connection of the additional Intermediate axte to the output shaft. [069] Accordingly, the transmission according to the invention can have — in addition to the shafts connected in a rotationally fixed manner to the two clutches K1 and K2 — three or four shafts, namely the drive shaft An. the output shaft Ab. an intermediate shaft W1, and — depending on the an-angement of the planetary transmission — an additional Intermediate shaft W2. This is the subject matter of FIGS. 7 and 3, whereas FIG. 7 represents a three-shaft an^ngement and FIG. 8 a four-shaft an-angement [070] FIG, 9 schematlcaiiy illustrates a first embodiment of a transmission according to the invention. It comprises a dual clutch with the clutches K1 and K2 and two partial transmissions which are designed as positive shifting planetary transmissions PG1, PG2, At least one spur gear stage and/or spur gear transmission ratio SI and/or S2 is associated with each planetary transmission. [071] The two clutches K1, K2 of the double clutch each act on two coaxial transmission Input shafts AW1 and/or AW2, which each act on one planetary transmission PG1 and/or PG2; the shaft AW1 is designed as a solid shaft and is arranged coaxiaily to the shaft AW2 designed as a hollow shaft. In the design embodiment shown in FIG. 9, the spur gear stages S1 and/or S2 associated with the planetary transmissions PG1, PG2 are aranged in the direction offeree flow after the planetary transmissions (that is, they are connected to the output of the particular planetary transmission), whereas the spur gear stage S1, according to the figure, is an^nged axially, or, when viewed spatially, is arranged to the left of the pianelary transmission PG1, and the spur gear stage S2 is an-anged axiaily, or, when viewed spatially, is arranged to the right of the planetary transmission PG2. As is evident in the figure, due to the spur gear stages SI and S2, the torque is transfen-ed to an intermediate shaft W1 arranged parallel to the drive shaft An, said intennediate shaft is actively connected to the output shaft Ab by means of an additional spur gear stage S3. The output shaft Ab and/or the output wheel is connected preferably to a dlfi'erential Diff which ensures either the compensation of speed between the right and left driven wheel (pure front drive) or between the front- and rear axle (all-wheel drive). Optionally, the speed compensation can also be handled by clutches and/or by so-called hang-on systems. [072] The design embodiment illustrated in FIG. 10 differs from the design embodiment according to FIG. 9 in that the spur gear stage 32 associated with the planetary transmission PG2 is arranged axiaily, or, when viewed spatially, is arranged to the left of the planetary transmission PG2. According to the invention, the spur gear stages, when viewed in the direction of force flow, can be arranged after the planetary transmissions and when viewed axiaily or spatially, can be an-anged to the right of the particular planetary transmission PG1 and/or PG2. This arrangement is the subject matter of FIG. 11; in the embodiment shown in FIG. 12» the spur gear stage S1 associated with the planetary transmission PG1 is arranged a)dally, or, when viewed spatially, is an-anged to the right of the planetary transmission PG1, whereas the spur gear stage S2 associated with planetary transmission PG2 Is an^nged axiaily, or, v.'hen viewed spatially, is an'anged to the left of planetary transmission PG2. [073] Within the scope of additional design embodiments of the invention, the spur gear stage associated with one planetary transmission can be arranged in the direction of force flow in front of the planetary transmission (that is, the planetary transmission is connected to the spur gear stage on the drive side). In this case, this planetary transmission is positioned on the intermediate shaft W1. FIGS. 13.14,15 and 16 illustrate design embodiments in which the transmission PG2 is an^nged on the intermediate shaft S1; these design embodiments difter in the spatial arrangement of the spur gear stages SI, 32 relative to the planetary transmissions PG1, PG2. [074] Of course, instead of the planetary transmission PG2, the planetary transmission PG1 can be arranged on the intermediate shaft and the transmission PG2 can be arranged coaxial to the drive siiaft instead of the transmission PG1. [075] In the design embodtmer^t shown in FIG. 13 the spur gear stage S2 associated with the planetary transmission PG2 is arranged axialiy. and/or when viewed spatially, is arranged to the right of the planetary transmission PG2 (that is, after the planetary transmission), and the spur gear stage SI associated with the planetary transmission PG1 is aranged in the direction of force flux after the planetary transmission PG1 and when viewed a>;ialfy, is an-anged to the left of the transmission PG1. [076] The design embodiment shown in FIG. 14 differs from the design embodiment according to FIG. 13 in that Itie spur gear stage S2 associated with the planetary transmission PG2 is located axialiy, or, when viewed spatially, is an'anged to the left of the planetary transmission PG2, and the design embodiment shown in FIG. 15 differs from the design embodiment according to FIG. 13 in that the spur gear stage S1 associated with the planetary transmission PG1 is an^anged axialiy, or, when viewed spatially, is arranged to the right of the transmission PG1. [077] Furthermore, FIG, 16 shows a transmission In which the spur gear stage S2 associated with the planetary transmission PG2 is an^nged axialiy, or, when viewed spatially, is an*anged to the left of the planetary transmission PG2, and the spur gear stage S1 associated with the planetary transmission PG1 is an^nged axialiy, or, when viewed spatially, is arranged to the right of the planetary transmission PG1. [078] FIGS. 17, 18, 19 and 20 present design embodiments of the invented transmission in which the two planetary transmissions PG1, PG2 associated with the spur gear stages SI, S2 are arranged in the direction of force flow in front of the planetary transmissions PG1 and/or PG2 (that is, the planetary transmissions are connected on the drive side to the associated spur gear stage). In this case, the planetary drives PGl, PG2 are arranged on the same intermediate axle parallel to the drive axle. The illustrated design embodiments differ in spatial an-angement of the spur gear stages SI, S2 relative to the planetary transmissions PG1, PG2. [079] In the embodiment shown in FIG. 17, the spur gear stage S2 associated with the planetary transmission PG2 is an-anged axialiy, or, Virfien viewed spatially, is arranged to the right of the planetary transmission PG2, whereas the spur gear stage S1 associated with the planetary transmission PG1 is arranged axialiy, or, when viewed spatially, is arranged to the left of the planetary transmission PG1* The design embodiment illustrated in FIG. 18 differs from the embodiment shown in FIG. 17 in that the spur gear stage S2 associated with the planetary transmission PG2 Is arranged axialiy. or, when viewed spatially. Is arranged to the left of the planetary transmlsston PG2. Furthermore, FIG. 19 shows a transmission whose design differs from the transmission shown in FIG. 17 in that the spur gear stage S1 associated with the planetary transmission PG1 is arranged axiaily, or, when viewed spatially, is arranged to the right of the planetary transmission PG1. As an alternative to the arrangements shown in FiGS. 17, 18 and 19, the spur gear stage S2 associated with the planetary transmission PG2 can be an-anged axlally, or, when viewed spatially, can be an-anged to the left of the planetary transmission PG2. and the spur gear stage SI associated with the planetary transmission PGl can be arranged axially, or, when viewed spatially, can be arranged to the right of planetary transmission PGl - An an^ngement of this t(aiinple. [096] The first gear is obtained by engaging the clutch K1 and the shift element s1, second gear by engaging the clutch K2 and the shift element s2, third gear by engaging the ciutch K1 and the shift element s3, and fourth gear by engaging clutch K2 and the shift element s4. Furthermore, fifth gear by engaging clutch K1 and shift element s5, and sixth gear by engaging clutch K2 and shift element s6. As is evident from the shifting outline, the reverse gear fs engaged by engaging the clutch Kl and shift element srl. [097] Due to the design according to the invention, a very compact structural unit is created; due to the short design length, the transmissions disclosed herein are optimal for a front-transverse arrangement; planetary transmissions are characterized by a high specific power density in comparison to countershaft transmissions, and more transmission ratios are possible with fewer elements. Furthermore, a transmission according to the Invention is lighter in comparison with conventional dual clutch transmissions with a countershaft design. [098] Within the scope of additional design embodiments, multl-ctutch transmissions with more than two partial transmissions can be used, In which the partial transmissions are designed analogous to the described examples for planetaiy transmissions. [099] An additional advantage consists In that the selection of transmission ratio has a wider range than in conventional planetary transmissions, so that the transmission can be adapted to the requirements. Due to the additional spur gear stages, the degree of freedom in selection of the transmission ratio increases, so that the transmission ratio can be selected with a high degree of accuracy, or can be varied in a favorable manner. [100] Furthermore, a transmission according to the invention can be produced at low cost due to the potential for reuse of parts and has a higher efficiency in comparison to conventional planetary transmissions, since low-loss synchronizing elements are used. In addition, two direct gears can be provided per partial transmission (one direct gear can be implemented In a conventional planetary transmission). [101] Of course, any other design embodiment, in particular any spatial arrangement of the planetary gear sets and of the shift elements with respect to each other and also where technically feasible, tails under the scope of protection of the claims herein without affecting the operation of the transmission as said operation is stated in the claims, even tf these embodiments are not explicitly presented in the figures or in the description. List of Reference Symbols K1 clutch K2 clutch PG1 planetary transmission PG2 planetary transmission An drive shaft Ab output shaft AW1 solid shaft AW2 hollow shaft W1 intemnedlate shaft W2 intermediate shaft S1 spur gear set S2 spur gear set S3 spur gear set S4 spur gear set SR spur gear set Diff differential G housing 1 transmission ratio phi gear step s1 shift element S2 shift element S3 shift element s4 shift element s5 shift element S6 shift element srI shift element sr2 shift element Patent Claims 1. Dual clutch transmission for a front-transverse arrangement comprising a dual clutch and two partial transmissions, whereas each of the two clutches (K1, K2) of the dual clutch acts on one coaxial transmission Input shaft (AW1, AW2), which acts upon a partial transmission, characterized in that the partial transmissions are designed as planetary transmissions (PG1. PG2) that are to be shifted in a positive manner, and that the output is performed on the same side of the transmission as the input and axially parallel to the Input, in the same rotational direction, whereas the torque is transmitted to the output shaft (Ab) by means of at least one intemiediate shaft (W1, W2) that njns parallel to the transmission input shafts (AW1, AW1). 2. Dual clutch transmission for a front-transverse arrangement according to claim 1, characterized in that the planetary transmissions (PG1, PG2) consist of at least one planetary gear set having a conventional design. 3. Dual clutch transmission for a front-transverse an'angement according to claim 2, characterized in that the planetary gear sets are designed as planar plus- or minus-planetary gear sets or as multiple-stage planetary gear sets. 4. Dual clutch transmission for a front-transverse arrangement according to claim 1, 2 or 3, characterized In that the planetary transmissions (PG1, PG2) can be shifted by synchronizing elements or by claw clutches. 5. Dual clutch transmission for a front-transverse an-angement according to one of the preceding claims, characterized in that the individual gears in the partial transmissions (PGV PG2) are prepared and shifted by means of the change of the clutch in the dual clutch, whereas each planetary transmission (PG1, PG2) has at least one-half minus one, of the necessary fonward gears, whereas one planetary transmission (PG1, PG2) represents either the even-numbered or the uneven-numbered gears 6. Dual clutch transmission for a front-transverse arrangement according to one of the preceding claims, characterized in that the reverse gears can be engaged by closing of one shift element of a planetary transmission or by an additional spur gear set and a positive shifting element. 7. Dual clutch transmission for a front-transverse arrangiement according to one of the preceding claims, characterized in that the partial transmissions (PG1, PG2) have the same design, 8. Dual clutch transmission for a front-transverse arrangement according to one of the preceding claims, characterized in that at least one spur gear set (S1, S2) is associated with each planetary transmission (PG1, PG2), said spur gear set is located axialty, or, when viewed spatially, is located to the left or right in front of the particular gear(PG1,PG2). 9. Dual clutch transmission for a front-transverse arrangement according to claim 8, characterized in that the spur gear sets ($1, S2) are located on the drive shaft (AW1. AW2) after the planetary transmissions (PG1, PG2) in the direction of force flux. 10. Dual clutch transmission for a front-transverse arrangement according to claim 8, characterized in that the spur gear sets (S1, S2) are located in front of the two planetary transmissions (PG1, PG2) in the direction of force flux, and the planetary transmissions (PG1, PG2) are located either on the same intermediate shaft (W1) which Is parallel to the drive axle, or on two different, parallel intermediate shafts (W1, W2). 11. Dual clutch transmission for a front-transverse anrangement according to claim 9, characterized in that two additional spur gear sets (S3, S4) are provided in order to ensure the linkage of the additional intermediate shafts (W1, W2) to the output shaft (Ab). 12. Dual clutch transmission for a front-transverse an^ngement according to daim 10, characterized fn that the spur gear sets (-S3, S4) each consist of a drive pinion and a driven wheel. 13. Dual clutch transmission for a front-transvense arrangement according to claim 10, characterized in that for both spur gear sets (S3, S4) a single driven wheel is provided, upon which both driven pinions act, whereas the spur gear sets (S3, S4) can be used as two separate transmission ratios. 14. Dual clutch transmission for a front-transverse arrangement according to claim 8, characterized in that a spur gear set (S1, S2) is located in the direction of force flux, in front of the planetary drive (PG1. PG2) associated therewith, and a spur gear set (S1, 32) is located in the direction of force flux after the planetary drive (PG1. PG2) associated therewith, whereas the pianetary drive whose associated spur gear set is located in the direction of force flux in front of said planetary drive, is located on the intermediate shaft (W1) parallel to the drive axle. 15. Dual clutch transmission for a front-transverse an-angement according to claim 8 or 13, characterized in that in the case of a single intermediate shaft (W1), an additional spur gear set (S3) is provided which linl^s the Intermediate shaft (W1) to the output shaft (Ab), 16. Dual clutch transmission for a front-transverse an^ngement according to one of the preceding claims, characterized in that the dual clutch is designed as a dual clutch module or as an "independent" dual clutch comprising two dutches located at different positions in the transmission. 17. Dual clutch transmission for a front-transverse arrangement according to one of the preceding claims, characterized In that the power flow from the engine proceeds by means of an optional element for reduction of the rotary oscillation, by means of a hydraulic torque converter, or by means of a hydraulic clutch in the dual clutch, 18. Dual clutch transmission for a front-transverse an'angement acconding to one of the preceding claims, characterized in that the output wheel and/or the output wheels are linked to a differentia! (Diff). which ensures either the speed compensation between right and left driven wheel (for a pure front-drive) or ensures the speed compensation between front and rear axle (all-wheel drive).