Abstract: A power transmission apparatus for a vehicle may include a first input shaft, a second input shaft, a third input shaft, an intermediate shaft disposed parallel to the first, second, and third input shafts, a transfer gear fixedly disposed on the intermediate shaft and outputting torque thereof, an first shifting member changing torque of an engine into first and second preliminarily shifted torques, and outputting the first and second preliminarily shifted torques, an second shifting member changing the torque of the engine into third and fourth preliminarily shifted torques, and outputting the third and fourth preliminarily shifted torques, and a third shifting member changing the torque of the engine transmitted from the first input shaft and the first preliminarily shifted torque to the fourth preliminarily shifted torque selectively transmitted from the first shifting member or the second shifting member into eight forward speed stages and one reverse speed stage.

Abstract: A hydraulic control system applicable to a power train of a seven-speed automatic transmission for a vehicle having six friction members. Enhanced overall performance is achieved by minimization of shift shock and an enhancement of fuel consumption as a consequence of achieving precise and effective control.

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 hydraulic control system applicable to a power train of a seven-speed automatic transmission for a vehicle having six friction members. Enhanced overall performance is achieved by minimization of shift shock and an enhancement of fuel consumption as a consequence of achieving precise and effective control.

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 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 hydraulic pressure regulating device for variable line pressure control is provided which comprises a valve housing, a sleeve, an adjustment screw assembly, a spring, and a valve spool. The valve housing defines a chamber therein. The sleeve is disposed in the chamber and is provided with a spring-receiving hole in one side thereof, and a projection portion is formed on an outer circumference of the sleeve to contact an inner surface of the valve housing. The adjustment screw assembly is configured to be able to adjust a position of the sleeve, and the sleeve is supported by the adjust screw assembly. One end of the spring is inserted into the spring-receiving hole such that the spring is supported by the sleeve. The valve spool is disposed in the chamber to be driven by a hydraulic pressure supplied into the chamber, and it is elastically supported by the spring.

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.