Patent ID: 7789792

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 ), 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 ) comprise 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 ) and first, second, third, fourth and fifth shifting elements (A, B, C, D, E), whose selective engagement defines different gear 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; wherein the planet carrier (ST 4 ) of the fourth planetary gear set (RS 4 ) and the input shaft (AN) are coupled and form the first shaft ( 1 ); the planet carrier (ST 3 ) of the third planetary gear set (RS 3 ) and the output shaft (AB) are coupled and form the second shaft ( 2 ); the sun gear (SO 1 ) of the first planetary gear set (RS 1 ) and the sun gear (SO 4 ) of the fourth planetary gear set (RS 4 ) are coupled and form the third shaft ( 3 ) of the transmission; the ring gear (HO 1 ) of the first planetary gear set (RS 1 ) forms the fourth shaft ( 4 ); the ring gear (HO 2 ) of the second planetary gear set (RS 2 ) and the sun gear (SO 3 ) of the third planetary gear set (RS 3 ) are coupled and form the fifth shaft ( 5 ); the planet carrier (ST 1 ) of the first planetary gear set (RS 1 ) and the ring gear (HO 3 ) of the third planetary gear set (RS 3 ) are coupled and form the sixth shaft ( 6 ); the sun gear (SO 1 ) of the second planetary gear set (RS 2 ) and the ring gear (HO 4 ) of the fourth planetary gear set (RS 4 ) are coupled and form the seventh shaft ( 7 ); the planet carrier (ST 2 ) of the second planetary gear set (RS 2 ) forms the eighth shaft ( 8 ); 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 located between the fourth shaft ( 4 ) and the housing (GG) of the transmission; the third shifting element (C) is located in a power flow between the fifth shaft ( 5 ) and the first shaft ( 1 ); the fourth shifting element (D) is located in the power flow between one of the eighth shaft ( 8 ) and the second shaft ( 2 ) and the eighth shaft ( 8 ) and the sixth shaft ( 6 ); and the fifth shifting element (E) is located in the power flow between one of the seventh shaft ( 7 ) and the fifth shaft ( 5 ), the seventh shaft ( 7 ) and the eighth shaft ( 8 ) and the fifth shaft ( 5 ) and the eighth shaft ( 8 ).