Patent ID: 7682282

Claim:
A multi-speed automatic transmission of a planetary design for a vehicle, the transmission comprising: an input shaft (AN) and an output shaft (AB); first, second, third, and fourth planetary gearsets (P 1 , P 2 , P 3 , P 4 ), and each of the first, the second, the third, and the fourth planetary gearsets (P 1 , P 2 , P 31 P 4 ) comprising a sun gear, a 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 ) and first, second, third, fourth and fifth shifting elements (A, B, C, D, F), whose selective engagement creates different gear ratios between the input shaft (AN) and the output shaft (AB) so that at least eight forward gears and one reverse gear can be implemented; wherein the carrier (ST 4 ) of the fourth planetary gearset (RS 4 ) is coupled to the input shaft (AN) and forms the first shaft ( 1 ); the carrier (ST 3 ) of the third planetary gearset (RS 3 ) is coupled to the output shaft (AB) and forms the second shaft ( 2 ); the sun gear (SO 1 ) of the first planetary gearset (RS 1 ) is coupled to the sun gear (S 04 ) of the fourth planetary gearset (RS 4 ) and forms the third shaft ( 3 ); the ring gear (HO 1 ) of the first planetary gearset (RS 1 ) forms the fourth shaft ( 4 ); the sun gear (SO 2 ) of the second planetary gearset (RS 2 ) is coupled to the sun gear (S 03 ) of the third planetary gearset (RS 3 ) and forms the fifth shaft ( 5 ); the carrier (ST 1 ) of the first planetary gearset (RS 1 ) is coupled to the ring gear (H 03 ) of the third planetary gearset (RS 3 ) and forms the sixth shaft ( 6 ); the carrier (ST 2 ) of the second planetary gearset (RS 2 ) is coupled to the ring gear (HO 4 ) of the fourth planetary gearset (RS 4 ) and forms the seventh shaft ( 7 ); the ring gear (H 02 ) of the second planetary gearset (RS 2 ) forms the eighth shaft ( 8 ); the first shifting element (A) is arranged 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, within a power flow, between the first shaft ( 1 ) and the fifth shaft ( 5 ); the fourth shifting element (D) is arranged, within the power flow, between one of the second shaft ( 2 ) and the eighth shaft ( 8 ) and the sixth shaft ( 6 ) and the eighth shaft ( 8 ); and the fifth shifting element (E) is arranged, within the power flow, between one of the fifth shaft ( 5 ) and the seventh shaft ( 7 ), the fifth shaft ( 5 ) and the eighth shaft ( 8 ) and the seventh shaft ( 7 ) and the eighth shaft ( 8 ).