Patent ID: 7597645

Claim:
A multi-speed automatic transmission of a planetary design for a motor vehicle, the transmission comprising: an input shaft ( 1 ) and an output shaft ( 2 ) are arranged in a housing (G); first, second and third planetary gear sets (P 1 , P 2 , P 3 ), and each of the first, the second and the third planetary gear sets (P 1 , P 2 , P 3 ) comprising a sun gear, a carrier, and a ring gear; at least, third, fourth, fifth, and sixth rotatable shafts ( 3 , 4 , 5 , 6 ) as well as at least six shifting elements ( 03 , 04 , 15 , 23 , 25 , 34 , 45 , 46 ), comprising first and second brakes ( 03 , 04 ) and first, second, third, fourth clutches ( 15 , 23 , 25 , 34 , 45 , 46 ), whose selective engagement creates different gear ratios between the input shaft ( 1 ) and the output shaft ( 2 ) so that at least seven forward gears and one reverse gear can be implemented; wherein the input shaft ( 1 ) is permanently connected to the ring gear of the first planetary set (P 1 ) and is detachably connected, via the first clutch ( 15 ), to the fifth shaft ( 5 ); the fifth shaft ( 5 )is permanently connected to the carrier of the third planetary set (P 3 ) and is detachably connected, via the third clutch ( 25 ), to the output shaft ( 2 ); the output shaft ( 2 ) is permanently connected to the ring gear of the second planetary set (P 2 ); the third shaft ( 3 ) is permanently connected to the ring gear of the third planetary set (P 3 ) and the carrier of the second planetary set (P 2 ) and is detachably coupled to the housing (G), via the first brake ( 03 ); the fourth shaft ( 4 ) is permanently connected to the sun gear of the second planetary set (P 2 ), and is detachably connected to the housing (G), via the second brake ( 04 ), and to the fourth shaft ( 6 ), via the sixth clutch ( 46 ); the sixth shaft ( 6 ) is permanently connected to the carrier of the first planetary set (P 1 ) and the sun gear of the third planetary set (P 3 ); and the sun gear of the first planetary set (P 1 ) is connected to the housing (G); and one of: the output shaft ( 2 ) is detachably connected, via the second clutch ( 23 ), to the third shaft ( 3 ), the second shaft ( 5 ) is detachably connected, via the fifth clutch ( 45 ), to the fourth shaft ( 4 ), and the third shaft ( 3 ) is detachably connected, via the second clutch ( 34 ), to the fourth shaft ( 4 ).