Patent ID: 8702554

Claim:
A multi-ratio transmission of planetary design for a motor vehicle, the multi-ratio transmission comprising: a drive input shaft ( 1 ) and a drive output shaft ( 2 ); first, second, third and fourth planetary gearsets (P 1 , P 2 , P 3 , P 4 ) arranged in a housing (G) of the transmission, each of the first planetary gearset (P 1 ), the second planetary gearset (P 2 ), the third planetary gearset (P 3 ) and the fourth planetary gearset (P 4 ) comprising a sun gear, a planet carrier and a ring gear; third, fourth, fifth, sixth, seventh and eighth shafts ( 3 , 4 , 5 , 6 , 7 , 8 ); at least six shifting elements comprising first, second and third brakes ( 04 , 03 , 05 ) and first, second and third clutches ( 14 , 17 , 78 ) and selective engagement the first brake ( 04 ), the second brake ( 03 ), the third brake ( 05 ), the first clutch ( 14 ), the second clutch ( 17 ) and the third clutch ( 78 ) results in various gear ratios between the drive input shaft ( 1 ) and the drive output shaft ( 2 ) such that first, second, third, fourth, fifth, sixth, seventh, eighth and ninth forward gears and one reverse gear can be implemented; the drive input shaft ( 1 ) is coupled to the sun gear of the first planetary gearset (P 1 ) and is connectable, via the first clutch ( 14 ), to the fourth shaft ( 4 ) and is connectable, via the second clutch ( 17 ), to the seventh shaft ( 7 ); the drive output shaft ( 2 ) is coupled to the planet carrier of the fourth planetary gearset (P 4 ); the third shaft ( 3 ) is coupled to the planet carrier of the first planetary gearset (P 1 ) and to the ring gear of the second planetary gearset (P 2 ) and is connectable, via the second brake ( 03 ), to the housing (G) of the transmission; the fourth shaft ( 4 ) is coupled to the planet carrier of the second planetary gearset (P 2 ) and to the ring gear of the third planetary gearset (P 3 ) and is connectable, via the first brake ( 04 ), to the housing (G) of the transmission; the fifth shaft ( 5 ) is coupled to the ring gear of the first planetary gearset (P 1 ) and is connectable, via the third brake ( 05 ), to the housing (G) of the transmission; the sixth shaft ( 6 ) is coupled to the planet carrier of the third planetary gearset (P 3 ) and to the ring gear of the fourth planetary gearset (P 4 ); the seventh shaft ( 7 ) is coupled to the sun gear of the fourth planetary gearset (P 4 ) and is connectable, via the third clutch ( 78 ), to the eighth shaft ( 8 ); and the eighth shaft ( 8 ) is coupled to the sun gear of the third planetary gearset (P 3 ) and to the sun gear of the second planetary gearset (P 2 ).