Patent ID: 8197376

Claim:
A multi-stage transmission of a planetary design for an automatic transmission for a motor vehicle comprising a drive shaft ( 1 ), an output shaft ( 2 ), and four planetary gear sets (P 1 , P 2 , P 3 , P 4 ) being arranged in a housing (G), the multi-stage transmission having a total of eight rotatable shafts ( 1 , 2 , 3 , 4 , 5 , 6 , 7 , 8 ) as well as at least six shift elements ( 03 , 04 , 05 , 13 , 28 , 37 ) comprising first, second and third brakes ( 03 , 04 , 05 ) and first, second and third clutches ( 13 , 28 , 37 ) whose selective engagement produces different transmission ratios, between the drive shaft ( 1 ) and the output shaft ( 2 ), for implementing nine forward gears and one reverse gear, wherein the sun gear of the first planetary gear set (P 1 ) is connected to the fourth shaft ( 4 ) which can be coupled to a transmission housing (G) by the first brake ( 04 ), the carrier of the first planetary gear set (P 1 ) is connected to the third shaft ( 3 ) which can be coupled to a transmission housing (G) via the second brake ( 03 ), the carrier of the first planetary gear set (P 1 ) is detachably connectable to the drive shaft ( 1 ) via the first clutch ( 13 ), and the carrier of the first planetary gear set (P 1 ) is detachably connectable to the seventh shaft ( 7 ), via a second clutch ( 37 ); the seventh shaft ( 7 ) is permanently connected to the ring gear of the second planetary gear set (P 2 ) and is connected to the sun gear of the fourth planetary gear set (P 4 ); the drive shaft ( 1 ) is permanently connected to the sun gear of the second planetary gear set (P 2 ) and to the carrier of the third planetary gear set (P 3 ); the sixth shaft ( 6 ) is permanently connected to the ring gear of the first planetary gear set (P 1 ), the carrier of the second planetary gear set (P 2 ) and the sun gear of the third planetary gear set (P 3 ), the ring gear of the fourth planetary gear set (P 4 ) is connected to the fifth shaft ( 5 ) which can be coupled to the transmission housing (G) via a third brake ( 05 ), and the output shaft ( 2 ) is detachably connectable to the eighth shaft ( 8 ), via a third clutch, which is connected to the ring gear of the third planetary gear set (P 3 ), and the output shaft ( 2 ) is permanently connected to the carrier of the fourth planetary gear set (P 4 ).