Patent ID: 8016708

Claim:
A multi-speed automatic transmission of a planetary design for a motor vehicle, the transmission comprising: an input shaft (AN) and an output shaft (AB); first, second, third and fourth planetary gear sets (RS 1 , RS 2 , RS 3 , RS 4 ), and each of the first planetary gear set (RS 1 ), the second planetary gear set (RS 2 ), the third planetary gear set (RS 3 ) and the fourth planetary gear set (RS 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 ), first, second, third, fourth and fifth gearshifting elements (A, B, C, D, E) whose selective engagement creates different gear ratios between the input shaft (AN) and the output shaft (AB) so that eight forward gears and at least one reverse gear can be implemented; wherein the first gearshifting element (A) is located in a force flow path between the third shaft ( 3 ) and a housing (GG) of the transmission; the second gearshifting element (B) is located in a force flow path between the fourth shaft ( 4 ) and the housing (GG) of the transmission; the third gearshifting element (C) is located in a force flow path between the first shaft ( 1 ) and the fifth shaft ( 5 ); the fourth gearshifting element (D) is located in a force flow path between the second shaft ( 2 ) and the eighth shaft ( 8 ); the fifth gearshifting element (E) is located in a force flow path between the fifth shaft ( 5 ) and the seventh shaft ( 7 ); the carrier (ST 4 ) of the fourth planetary gearset (RS 4 ) and the input shaft (AN) are coupled to one another and form the first shaft ( 1 ); the carrier (ST 3 ) of the third planetary gearset (RS 3 ) and the output shaft (AB) are coupled to one another and form the second shaft ( 2 ); the sun gear (SO 1 ) of the first planetary gearset (RS 1 ) and the sun gear (SO 4 ) of the fourth planetary gearset (RS 4 ) are coupled to one another and form 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 3 ) of the third planetary gearset (RS 3 ) forms the fifth shaft ( 5 ); the carrier (ST 1 ) of the first planetary gearset (RS 1 ) and the carrier (ST 2 ) of the second planetary gearset (RS 2 ) and the ring gear (HO 3 ) of the third planetary gearset (RS 3 ) are coupled to one another and form the sixth shaft ( 6 ), the sun gear (SO 2 ) of the second planetary gearset (RS 2 ) and the ring gear (HO 4 ) of the fourth planetary gearset (RS 4 ) are coupled to one another and form the seventh shaft ( 7 ); and the ring gear (HO 2 ) of the second planetary gearset (RS 2 ) forms the eighth shaft ( 8 ).