Patent ID: 7621840

Claim:
A multi-speed automatic transmission of a planetary design for a motor vehicle, the transmission comprising: an input shaft (AN); an output shaft (AB); first, second, third and fourth planetary gearset (RS 1 , R 52 , R 53 , R 54 ); at least first, second, third, fourth, fifth, sixth, seventh and eighth rotatable shafts ( 1 , 2 , 3 , 4 , 5 , 6 , 7 , 8 ); and first, second, third, fourth and fifth shifting elements (A, B, C, D, E) whose selective engagement generates a plurality of reduction ratios between the input shaft (AN) and the output shaft (AB) such that eight forward gears and at least one reverse gear can be implemented; a sun gear (SO 1 ) of the first planetary gearset (RS 1 ) and a sun gear (SO 4 ) of the fourth planetary gearset (R 54 ) are connected with one another and form the third shaft ( 3 ); a ring gear (HO 1 ) of the first planetary gearset (RS 1 ) forms the fourth shaft ( 4 ); a carrier (ST 1 ) of the first planetary gearset (RS 1 ) and a ring gear (HO 3 ) of the third planetary gearset (RS 3 ) are connected with one another and form the sixth shaft ( 6 ); a carrier (ST 2 ) of the second planetary gearset (RS 2 ) forms the eighth shaft ( 8 ); a ring gear (HO 4 ) of the fourth planetary gearset (RS 4 ) and the input shaft (AN) are connected with one another and form the first shaft ( 1 ); a ring gear (HO 2 ) of the second planetary gearset (RS 2 ) and a carrier (ST 3 ) of the third planetary gearset (RS 3 ) and the output shaft (AB) are connected with one another and form the second shaft ( 2 ); a sun gear (SO 3 ) of the third planetary gearset (RS 3 ) forms the fifth shaft ( 5 ); a sun gear (SO 2 ) of the second planetary gearset (RS 2 ) and a carrier (ST 4 ) of the fourth planetary gearset (RS 4 ) are connected with one another and form the seventh shaft ( 7 ); the first shifting element (A) is located between the third shaft ( 3 ) and a housing (GG) of the transmission; the second shifting element (B) is arranged between the fourth shaft ( 4 ) and the housing (GG) of the transmission; the third shifting element (C) is arranged, in a direction of power flow, between the first shaft ( 1 ) and the fifth shaft ( 5 ); the fourth shifting element (D) is arranged, in a direction of power flow, between the sixth shaft ( 6 ) and the eighth shaft ( 8 ); and the fifth shifting element (E) is arranged, in a direction of power flow, between the fifth shaft ( 5 ) and the seventh shaft ( 7 ).