Abstract: A planetary gear train of an automatic transmission for a vehicle, may include an input shaft receiving power; an output shaft outputting power; a first planetary gear set having first, second, and third rotation elements; a second planetary gear set having fourth, fifth, and sixth rotation elements; a third planetary gear set having seventh, eighth, and ninth rotation elements; a fourth planetary gear set having tenth, eleventh, and twelfth rotation elements; a fifth planetary gear set having thirteenth, fourteenth, and fifteenth rotation elements; and first to ninth shafts connecting the rotation elements of the first planetary gear set to the fifth planetary gear set.

Abstract: A planetary gear train of an automatic transmission for a vehicle may include an input shaft receiving torque of an engine, an output shaft outputting changed torque, a first planetary gear set including first, second, and third rotation elements, a second planetary gear set including fourth, fifth, and sixth rotation elements, a compound planetary gear set formed by combining third and fourth planetary gear sets and including seventh, eighth, ninth, and tenth rotation elements, a fifth planetary gear set including eleventh, twelfth, and thirteenth rotation elements, and six friction elements disposed between at least one rotation element among thirteen rotation elements and another rotation element or the input shaft, or between at least one rotation element among the thirteen rotation elements and a transmission housing.

Abstract: An control system and method for an automatic transmission are disclosed which are adapted to shift or actuate the gears of the transmission without engine vacuum assistance. A control valve is provided which is variably positionable in response to a pressure signal from a governor to select control positions controlling the flow of hydraulic fluid to the gear shift elements of the transmission. The control valve is biased at a first select control position and is movable in response to the pressure signal from the governor to a second select control position for providing hydraulic fluid to the gear shift elements at a pressure effective for actuating the elements at a preselect vehicle speed. An adjustable position delimiter maintains the control valve at the second preselect control position.

Abstract: A power transmission for driving a vehicle wherein a high-low speed changer is disposed between an engine and a primary speed change mechanism. The speed changer comprises a planetary gear mechanism provided between an input shaft and an output shaft, a speed increasing clutch for causing the gear mechanism to effect a speed increase, and a direct coupling clutch for coupling the input shaft to the output shaft via the gear mechanism without speed change. Since the torque transmitted to the speed change mechanism is small, the transmission can be compact in its entirety.