Patent ID: 7670246

Claim:
A multi-speed automatic gearbox of a planetary design for a motor vehicle, the gearbox comprising: an input shaft (AN) and an output shaft (AB); first, second, third and fourth planetary gearsets (RS 1 , RS 2 , RS 3 , RS 4 ), the first planetary gearset (RS 1 ), the second planetary gearset (RS 2 ), the third planetary gearset (RS 3 ), and the fourth planetary gearset (RS 4 ) each have a carrier, a sun gear and a ring gear; at least first, second, third, fourth, fifth, sixth, seventh and eighth shafts ( 1 , 2 , 3 , 4 , 5 , 6 , 7 , 8 ); first, second, third, fourth and fifth shifting elements (A, B, C, D, E), whose selective engagement determines a variety 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; the carrier (ST 4 ) of the fourth planetary gearset (RS 4 ) is connected to the input shaft (AN) to form the first shaft ( 1 ); the ring gear (HO 2 ) of the second planetary gearset (RS 2 ) and the carrier (ST 3 ) of the third planetary gearset (RS 3 ) and the output shaft (AB) are connected to form the second shaft ( 2 ) the sun gear (SO 1 ) of the first planetary gearset (RS 1 ) is connected to the sun gear (SO 4 ) of the fourth planetary gearset (RS 4 ) to 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 ) is connected to the ring gear (HO 3 ) of the third planetary gearset (RS 3 ) to form the sixth shaft ( 6 ); the sun gear (SO 2 ) of the second planetary gearset (RS 2 ) is connected to the ring gear (HO 4 ) of the fourth planetary gearset (RS 4 ) to form the seventh shaft ( 7 ); the carrier (ST 2 ) of the second planetary gearset (RS 2 ) forms the eight shaft ( 8 ); the first shifting element (A) is arranged within the power flow between the third shaft ( 3 ) and a transmission housing (GG); the second shifting element (B) is arranged within the power flow between the fourth shaft ( 4 ) and the transmission housing (GG); the third shifting element (C) is arranged within the power flow between the first shaft ( 1 ) and the fifth shaft ( 5 ); the fourth shifting element (D) is arranged within the power flow between the fifth shaft ( 5 ) and the eighth shaft ( 8 ); and the fifth shifting element (E) is arranged within the power flow between the fifth shaft ( 5 ) and the seventh shaft ( 7 ).