Twin clutch transmission with coaxial drive and output

1. A twin clutch transmission ( 10 ) comprising:

a transmission input shaft ( 11 ) and a transmission output shaft ( 12 ) that are arranged coaxially with respect to one another;

two countershafts ( 16 , 33 ), further comprising a first countershaft ( 33 ) and a second countershaft ( 16 ), said two countershafts being arranged offset in parallel with respect to one another, and to the transmission input shaft ( 11 ) and to the transmission output shaft ( 12 );

a direct gear;

a plurality of forward gears, wherein

even-numbered forward gears of said plurality of forward gears are assigned to the first countershaft ( 33 );

odd-numbered forward gears of said plurality of forward gears are assigned to the second countershaft ( 16 ); and

the transmission input shaft is coupled to the second countershaft via two gearwheels in a first gearwheel stage, the second countershaft is coupled to the transmission output shaft via two gearwheels in a second gearwheel stage, and each of said plurality of forward gears taking place via at least two gearwheel stages;

a plurality of shift sleeves, comprising a first shift sleeve ( 24 ), a second shift sleeve ( 38 ), a third shift sleeve ( 32 ), and a fourth shift sleeve ( 28 ), wherein

said first shift sleeve is assigned to two forward gears, is arranged coaxially on the transmission output shaft ( 12 ), and is offset axially with respect to said second shift sleeve ( 38 ) assigned to the direct gear and to a further forward gear;

said third shift sleeve and fourth shift sleeve( 32 , 28 ) are arranged in a shift sleeve plane and are offset axially with respect to said first shift sleeve and said second shift sleeve; and

each of said third shift sleeve and said fourth shift sleeve is assigned to one of said two countershafts.

2. The twin clutch transmission as claimed in claim 1 , wherein a reversal of direction of rotation in a reversing mode is implemented by means of an additional intermediate wheel.

3. The twin clutch transmission as claimed in claim 1 , wherein a reversal of direction of rotation in a reversing mode is implemented by means of an additional intermediate shaft ( 41 ).

4. The twin clutch transmission as claimed in claim 1 , wherein a reversal of direction of rotation in a reversing mode is implemented solely by means of gearwheels which are arranged coaxially with respect to the input and the output shaft or to the two countershafts.

5. The twin clutch transmission as claimed in claim 1 , wherein a number s of the shift sleeves mounted in the twin clutch transmission is calculated from the number n of forward gears, for an odd number n from:

s

=

n

+

1

2

,

and, for an even number n, from:

s

=

n

+

2

2

.

6. The twin clutch transmissions as claimed in claim 1 , wherein the two countershafts ( 16 , 33 ) and the input shaft ( 11 ) dispose at least approximately in one plane.

7. The twin clutch transmission as claimed in claim 1 , wherein the two countershafts ( 16 , 33 ) and the input shaft ( 11 ) are arranged in triangular form.

8. The twin clutch transmission as claimed in claim 1 , wherein at least one gearwheel positions in different gear stages in the torque path.

9. The twin clutch transmission as claimed in claim 1 , wherein the twin clutch transmission ( 10 ) is installed in a motor vehicle having an engine arranged longitudinally in the direction of travel and has

n sequentially power-shiftable forward gears,

two intermediate shafts ( 14 , 15 ) which are arranged coaxially with respect to one another and one of which is designed as a hollow shaft ( 14 ) and

two friction clutches (K 1 , K 2 ) arranged concentrically with respect to the intermediate shafts ( 14 , 15 ),

all the forward gears being actuated in each case by the selection of a single shift sleeve assigned to the respective forward gear, and one of these forward gears being designed as the direct gear.

10. The twin clutch transmission as claimed in claim 9 , wherein the direct gear is designed as forward gear n, n−1 or −2.

11. The twin clutch transmission as claimed in claim 1 , wherein a first forward gear (Gl) and a reverse gear (R 1 ) are arranged in such a way that, for alternately shifting back and forth between the first forward gear and this reverse gear (“rocking cycle”), only an alternate actuation of input-side clutches (K 1 and K 2 ), without the actuation of the shift sleeve, is required.

12. The twin clutch transmission as claimed in claim 11 , wherein this said reverse gear for alternately shifting back and forth with the first forward gear is a first reverse gear (R 1 ).