Patent ID: 8088033

Claim:
A multi-speed automatic transmission of planetary design for a motor vehicle, the transmission comprising: an input (An) and an output (Ab) which are arranged in a housing (G) of the transmission; first, second, third and fourth planetary gear sets (P 1 , P 2 . P 3 , P 4 ), each of the first, the second, the third and the fourth planetary gear sets (P 1 , P 2 , P 3 , P 4 ) comprises at least a sun gear, a planet carrier and a ring gear; at least first, second, third, fourth, fifth, sixth, seventh and eighth rotatable shafts ( 1 , 2 , 3 , 4 , 5 , 6 , 7 , 8 ); at least six shifting elements ( 03 , 04 , 05 , 48 , 67 , 78 ) comprising first, second and third brakes ( 03 , 04 , 05 ) and first, second and third clutches ( 48 , 67 , 78 ), and selective engagement of the at least six shifting elements ( 03 , 04 , 05 , 48 , 67 , 78 ) creates different gear ratios between the input (An) and the output (Ab) such that at least six forward gears and three reverse gears can be implemented; the first shaft ( 1 ) being integrally coupled to the input (An) and the planet carrier of the first planetary gear set (P 1 ); the second shaft ( 2 ) being integrally coupled to the output (Ab), the planet carrier of the third planetary gear set (P 3 ) and the planet carrier of the fourth planetary gear set (P 4 ); the third shaft ( 3 ) being integrally coupled to the ring gear of the second planetary gear set (P 2 ) and the sun gear of the first planetary gear set (P 1 ); the fourth shaft ( 4 ) being integrally coupled to the ring gear of the third planetary gear set (P 3 ) and the sun gear of the fourth planetary gear set (P 4 ); the fifth shaft ( 5 ) being integrally coupled to the ring gear of the fourth planetary gear set (P 4 ); the sixth shaft ( 6 ) being integrally coupled to the sun gear of the second planetary gear set (P 2 ) and the ring gear of the first planetary gear set (P 1 ); the seventh shaft ( 7 ) being integrally coupled to the sun gear of the third planetary gear set (P 3 ); the eighth shaft ( 8 ) being integrally coupled to the planet carrier of the second planetary gear set (P 2 ); the first brake ( 03 ) detachably coupling the third shaft ( 3 ) to the housing (G) of the transmission; the second brake ( 04 ) detachably coupling the fourth shaft ( 4 ) to the housing (G) of the transmission; the third brake ( 05 ) detachably coupling the fifth shaft ( 5 ) to the housing (G) of the transmission; the first clutch ( 48 ) detachably coupling the fourth shaft ( 4 ) to the eighth shaft ( 8 ); the second clutch ( 67 ) detachably coupling the sixth shaft ( 6 ) to the seventh shaft ( 7 ); and the third clutch ( 78 ) detachably coupling the seventh shaft ( 7 ) to the eighth shaft ( 8 ).