Patent ID: 7294088

Claim:
A six-speed powertrain of an automatic transmission comprising first, second, and third planetary gear sets, an input shaft, and a transmission case, wherein: the first planetary gear set is a first single pinion planetary gear set, the second planetary gear set is a second single pinion planetary gear set, and the third planetary gear set is a double pinion planetary gear set; the first single pinion planetary gear set has a first sun gear, two first planet carriers, a first planetary gear, and a first ring gear; the second single pinion planetary gear set has a second sun gear, a second planetary gear, and a second ring gear; the double pinion planetary gear set is disposed adjacent to the second single pinion planetary gear set and has a third sun gear, a pair of third planetary gears, and a third ring gear; one planetary gear of the pair of third planetary gears and the second planetary gear are commonly connected by a common planet carrier such that the second and third planetary gears may independently rotate; the third ring gear and the first ring gear are fixedly connected such that they are integrally formed; the second ring gear and one first planet carrier are fixedly connected; and a torque of the input shaft is always transmitted to the second sun gear or the third sun gear.