Abstract: A six-speed powertrain of an automatic transmission is formed by combining three simple planetary gear sets, and an output element is realized as a single element without combination with a clutch. Therefore, because a torque load of a respective clutch is reduced, durability may be enhanced and a length of the transmission may be minimized.

Abstract: Six forward speeds and one reverse speed may be realized with minimized length and weight of the transmission by employing two single pinion planetary gear sets and a double pinion planetary gear set. One planetary gear of the double pinion planetary gear set is interconnected with an adjacent second planetary gear of the second single pinion planetary gear set by a common planet carrier such that they may rotate independently, and at the same time, at least two ring gears are integrated so as to enhance strength in the axial direction.

Abstract: A six-speed powertrain of an automatic transmission includes a first single pinion planetary gear set having a first sun gear, two first planet carriers, a first planetary gear, and a first ring gear. A second single pinion planetary gear set has a second sun gear, a second planetary gear, and a second ring gear. A double pinion planetary gear set 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.

Abstract: A variable compound planetary gearset forms five operational elements by having its single and double pinion planetary gearsets be interconnected by a shared planet carrier. The variable compound planetary gearset forms six forward speeds and one reverse speeds by receiving input torque through two input routes fixedly or variably connected to a simple planetary gearset and one input route variably connected to an input shaft.

Abstract: A multiple speed automatic transmission having eight forward speeds and one reverse speed is realized by combining two simple planetary gear sets and one compound planetary gear set by five clutches and two brakes. Power is delivered efficiently and fuel consumption is enhanced due to the increased number of speeds of the automatic transmission. Step ratios of the eight forward speeds can harmonized so as to gradually decrease from the lower gear to the higher gear, thus shift-feel is be enhanced. Additionally, hill climbing ability in the reverse speed is also enhanced by increasing the speed ratio of the reverse speed.

Abstract: A six-speed powertrain includes a simple planetary gearset having three operational elements and a compound planetary gearset having four operational elements. Regarding the four operational elements of the compound planetary gearset, two of them are variably connected to an input shaft where one of the two is variable connected to a transmission case, another one always acts as an output element, and the other one variably receives torque from the simple planetary gearset at a reduce speed.

Abstract: A six-speed powertrain of an automatic transmission includes a first single pinion planetary gear set having a first sun gear, two first planet carriers, a first planetary gear, and a first ring gear. A second single pinion planetary gear set has a second sun gear, a second planetary gear, and a second ring gear. A double pinion planetary gear set 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.

Abstract: A six-speed powertrain includes a simple planetary gearset having three operational elements and a compound planetary gearset having four operational elements. Regarding the four operational elements of the compound planetary gearset, two of them are variably connected to an input shaft where one of the two is variable connected to a transmission case, another one always acts as an output element, and the other one variably receives torque from the simple planetary gearset at a reduce speed.

Abstract: A six-speed powertrain of an automatic transmission includes a first single pinion planetary gear set having a first sun gear, two a first planet carriers carrier, a first planetary gear, and a first ring gear. A second single pinion planetary gear set has a second sun gear, a second planetary gear, and a second ring gear. A double pinion planetary gear set 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.