A planetary gear train of an automatic transmission for a vehicle includes at least ten forward speeds and one reverse speed. The planetary gear train includes an input shaft, an output shaft, four planetary gear sets respectively having three rotational elements, and six control elements for selectively interconnecting the rotational elements and a transmission housing.

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 torque of the engine, a first planetary gear set, a second planetary gear set, a third planetary gear set, a fourth planetary gear set, a first shaft, a second shaft, a third shaft, a fourth shaft directly connected to the input shaft, a fifth shaft selectively connectable to the second shaft, a sixth shaft, a seventh shaft selectively connectable to the fourth shaft, and an eighth shaft selectively connectable to at least one of the second shaft and the seventh shaft, and directly connected to the output shaft.

Transmissions with at least three gearing-arrangements with similar first and second gearing-arrangements that produce a number of transmissions having an eleven forward-speed and two reverse-speed ratios, having ten forward-speed and three reverse-speed ratios, and having five forward-speed and one reverse-speed ratios by selective engagement of three shift-elements in various combinations. Some embodiments include four simple planetary-gearsets and six shift-elements of which two or three are brakes. Another embodiment includes a double-pinion planetary-gearset and six shift-elements of which three are brakes. Other embodiments include three simple planetary-gearsets and five shift-elements of which one or two are brakes.

A transmission for a vehicle may include a first planetary gear set, a second planetary gear set, a third, planetary gear set, and a fourth planetary gear set each including three rotary elements, and a plurality of friction members, in which the friction members are connected to at least one or more of the rotary elements of the planetary gear sets and control rotation of the rotary elements.

The present disclosure provides a planetary gear train of an automatic transmission for a vehicle having advantages of improving power delivery performance and fuel economy by achieving at least ten forward speed stages and one reverse speed stage. The planetary gear train may include: first, second, third, and fourth planetary gear sets disposed on the same axis; an input shaft; an output shaft; eight rotation shafts connected to at least one of rotation elements of the first, second, third, and fourth planetary gear sets; four clutches and two brakes that are control elements; and a transmission housing. Torque input from the input shaft is changed by cooperation of the first, second, third, and fourth planetary gear sets, and the changed torque is output through the output shaft.

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 of the engine, 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 third planetary gear set including seventh, eighth, and ninth rotation elements, a fourth planetary gear set including tenth, eleventh, and twelfth rotation elements, and seven friction elements disposed between at least one rotation element among the twelve rotation elements and another rotation element or the input shaft, or between at least one rotation element among the twelve rotation elements and a transmission housing.

A multi-stage transmission for a vehicle may include an input shaft; an output shaft; first to fourth planetary gear devices transmitting rotary force between the input and output shafts, each of them having three rotary elements, and at least six shifting elements connected to the rotary elements of the planetary gear devices; wherein a first rotary element of the first planetary gear device is variably connected to a first rotary element and a third rotary element of the second planetary gear device, a second rotary element is continuously connected to the input shaft and variably connected to the first rotary element of the second planetary gear device, and a third rotary element is installed to be fixable by any one of the shifting elements and continuously connected to a third rotary element of the third planetary gear device.

A transmission for a vehicle may include a first planetary gear set, a second planetary gear set, a third, planetary gear set, and a fourth planetary gear set each including three rotary elements, and a plurality of friction members, in which the friction members are connected to at least one or more of the rotary elements of the planetary gear sets and control rotation of the rotary elements.

The present disclosure provides a planetary gear train of an automatic transmission for a vehicle including an input shaft, an output shaft, four planetary gear sets respectively having three rotational elements, and six control elements for selectively interconnecting the rotational elements and a transmission housing.

A transmission (G) is provided having four planetary gear sets (P1, P2, P3, P4), several shafts (W1-W8) and a first, second, third, fourth and fifth shift element (B1, B2, K1, K2, K3), the selective meshing of which brings about different transmission ratio relationships between a transmission input shaft (GW1) and a transmission output shaft (GW2). The transmission (G) includes a sixth shift element (K4), through which the fifth shaft (W5) is connectable to the sun gear (So-P4) of the fourth planetary gear set (P4).