Patent ID: 8870704

Claim:
An automatic multistage transmission of a planetary design for a motor vehicle, the multistage transmission comprising: a basic transmission ( 7 ) and a reduction stage ( 8 ) that is located downstream of the basic transmission ( 7 ), and both the basic transmission ( 7 ) and the reduction stage ( 8 ) being located in a common housing (G); the basic transmission ( 7 ) comprising: a drive shaft ( 1 ), an output shaft ( 2 ) and third, fourth, fifth and sixth rotatable shafts ( 3 , 4 , 5 , 6 ); first, second and third planetary gear sets (P 1 , P 2 , P 3 ) which are located within the housing (G), each of the first planetary gear set (P 1 ), the second planetary gear set (P 2 ) and the third planetary gear set (P 3 ) comprising a sun gear, a ring gear and a carrier; five shift elements (A, B, D, E, F) comprising first, second and third brakes (D, E, F) and first and second clutches (A, B) and selective engagement thereof resulting in first, second, third, fourth, fifth, sixth and seventh forward gear transmission ratios, from highest to lowest transmission ratio respectively, between the drive shaft ( 1 ) and the output shaft ( 2 ); the drive shaft ( 1 ) being continuously connected to the sun gear of the first planetary gear set (P 1 ) and being connectable, via the first clutch (A), to the sixth shaft ( 6 ) and, via the second clutch (B), to the fifth shaft ( 5 ); the output shaft ( 2 ) being continuously connected to the carrier of the third planetary gear set (P 3 ); the third shaft ( 3 ) being continuously connected to the ring gear of the first planetary gear set (P 1 ) and being connectable, via the first brake (D), to the housing (G); the fourth shaft ( 4 ) being continuously connected to the carrier of the first planetary gear set (P 1 ) and the ring gear of the second planetary gear set (P 2 ), and being connectable, via the second brake (E), to the housing (G); the fifth shaft ( 5 ) being continuously connected to the carrier of the second planetary gear set (P 2 ) and the ring gear of the third planetary gear set (P 3 ), and being connectable, via the third brake (F), to the housing (G); and the sixth shaft ( 6 ) being continuously connected to the sun gear of the second planetary gear set (P 2 ) and to the sun gear of the third planetary gear set (P 3 ); the reduction stage ( 8 ) comprising: a fourth planetary gear set (P 4 ) designed as a minus planetary gear set (P 4 ) having a sun gear, a ring gear and a carrier; the carrier of the fourth planetary gear set (P 4 ) being continuously connected to the output shaft ( 2 ); the ring gear of the fourth planetary gear set (P 4 ) being connectable, via a fourth brake (H), to the housing (G), the fourth brake (H) being designed as a form-locking shift element, the fourth brake being engaged in the first transmission ratio, and the sun gear of the fourth planetary gear set (P 4 ) being continuously connected to the sixth shaft ( 6 ).