Patent ID: 8444525

Claim:
A multi-stage transmission of a planetary design for a motor vehicle, the multi-stage transmission comprising: an input drive shaft ( 1 ) and an output shaft ( 2 ); first, second, third and fourth planetary gear sets (P 1 , P 2 , P 3 , P 4 ) being disposed within a housing (G) of the transmission, each of the first, the second, the third and the fourth planetary gear sets (P 1 , P 2 , P 3 , P 4 ) comprising a sun gear, a ring gear and a carrier; third, fourth, fifth, sixth, seventh and eighth rotatable shafts ( 3 , 4 , 5 , 6 , 7 , 8 , 8 ′) and at least six shift elements ( 03 , 04 , 05 , 13 , 18 , 36 , 78 ) comprising first, second and third brakes ( 04 , 03 , 05 ) and first, second and third clutches ( 13 , 18 , 78 , 36 ) whose selective engagement produces different transmission ratios between the drive shaft ( 1 ) and the output shaft ( 2 ), such that nine forward gears and one reverse gear being realizable; the sun gear of the first planetary gear set (P 1 ) being connected to the fourth shaft ( 4 ) which is connectable, via the first brake ( 04 ), to the housing (G) of the transmission; the carrier of the first planetary gear set (P 1 ) being connected to the third shaft ( 3 ) which is one of (a) connectable to the housing (G) of the transmission via the second brake ( 03 ), (b) connectable to the drive shaft ( 1 ), via the first clutch ( 13 ), and (c) connectable to the sixth shaft ( 6 ) via the second clutch ( 36 ); the sixth shaft ( 6 ) being connected to the ring gear of the second planetary gear set (P 2 ) and to the sun gear of the fourth planetary gear set (P 4 ); the drive shaft ( 1 ) being connected to the sun gear of the second planetary gear set (P 2 ) and is operatively connected to the carrier of the third planetary gear set (P 3 ); the seventh shaft ( 7 ) being connected to the ring gear of the first planetary gear set (P 1 ) and to the carrier of the second planetary gear set (P 2 ) and is operatively connected to the sun gear of the third planetary gear set (P 3 ); the ring gear of the fourth planetary gear set (P 4 ) being connected to the fifth shaft ( 5 ) which is connectable, via the third brake ( 05 ), to the housing (G) of the transmission; and the output shaft ( 2 ) being connected to the ring gear of the third planetary gear set (P 3 ) and to the carrier of the fourth planetary gear set (P 4 ).