Abstract: A planetary gear train of automatic transmission may include input shaft, output gear, first to fourth planetary gear sets, first rotating shaft including first sun gear, second rotating shaft including first planet carrier, second ring gear, third planet carrier, and fourth ring gear, third rotating shaft including first ring gear and third ring gear, and selectively connected to transmission housing, fourth rotating shaft including second sun gear, and selectively connected to transmission housing, fifth rotating shaft including second planet carrier, and selectively connected with first rotating shaft and simultaneously and directly connected with input shaft, sixth rotating shaft including third sun gear, seventh rotating shaft including fourth sun gear, and selectively connected with sixth rotating shaft and simultaneously and selectively connected to transmission housing, eighth rotating shaft including fourth planet carrier, and selectively connected with sixth rotating shaft and simultaneously and dir

Abstract: A multi-stage transmission for a vehicle may include an input shaft and an output shaft, a first planetary gear device, a second planetary gear device, a third planetary gear device, and a fourth planetary gear device provided between the input shaft and the output shaft so as to transfer a torque and each including three rotating elements, and at least six shifting elements connected to the rotating elements of the first to fourth planetary gear devices.

Abstract: A planetary gear train of an automatic transmission for a vehicle may include an input shaft into which power of an engine is input, an output shaft that outputs the shifted power, a first planetary gear set, a second planetary gear set, a third planetary gear set, a fourth planetary gear set, a first rotational shaft selectively connected to a transmission housing, a second rotational shaft directly connected to the input shaft, a third rotational shaft, a fourth rotational shaft, a fifth rotational shaft selectively connected to the first rotational shaft and the second rotational shaft, a sixth rotational shaft directly connected to the output shaft, and selectively connected to the fourth rotational shaft, a seventh rotational shaft selectively connected to the transmission housing, an eighth rotational shaft selectively connected to the fifth rotational shaft, and six friction elements.

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, a second planetary gear set, a third planetary gear set including, a fourth planetary gear set, a first rotation shaft, a second rotation shaft selectively connected to a transmission housing, a third rotation shaft selectively connected to the transmission housing, a fourth rotation shaft selectively connected to the second shaft or the third shaft, a fifth rotation shaft directly connected to the input shaft, a sixth rotation shaft, a seventh rotation shaft selectively connected to the transmission housing, and an eighth rotation shaft selectively connected to the sixth rotation shaft, and directly connected to the output shaft.

Abstract: A transmission for vehicles may include a first planetary gear set, a second planetary gear set, a third planetary gear set, and a fourth planetary gear set each of the first, second and third planetary gear sets including three rotary elements; and a plurality of friction members, wherein the friction members are connected to at least one of the rotary elements of the planetary gear sets and control rotation of the rotary elements.

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, a second planetary gear set, a third planetary gear set, a fourth planetary gear set, a first rotation shaft, a second rotation shaft directly connected to the input shaft, a third rotation shaft, a fourth rotation shaft selectively connected to the first rotation shaft or the second rotation shaft, a fifth rotation shaft selectively connected to a transmission housing, a sixth rotation shaft selectively connected to the transmission housing, a seventh rotation shaft selectively connected to the first rotation shaft, and an eighth rotation shaft directly connected to the output shaft, and selectively connected to the first rotation shaft.

Abstract: A planetary gear train of an automatic transmission for a vehicle may include an input shaft receiving power of an engine, an output shaft outputting shifted power, a first planetary gear set, a second planetary gear set, a third planetary gear set, a fourth planetary gear set, a first rotational shaft selectively connected with a transmission housing, a second rotational shaft, a third rotational shaft selectively connected with the transmission housing, a fourth rotational shaft directly connected with the input shaft to be continuously operated as an input element, a fifth rotational shaft selectively connected with the second rotational shaft, a sixth rotational shaft selectively connected with the second rotational shaft, a seventh rotational shaft directly connected with the output shaft to be continuously operated as an output element, an eighth rotational shaft selectively connected with the input shaft and the sixth rotational shaft, and six frictional elements.

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 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 rotation shaft, a second rotation shaft, a third rotation shaft directly connected to the output shaft, a fourth rotation shaft selectively connected to the second rotation shaft and selectively connected to a transmission housing, a fifth rotation shaft, a sixth rotation shaft directly connected to the input shaft, and selectively connected to the second rotation shaft, a seventh rotation shaft including the third planet carrier, selectively connected to the first rotation shaft, and selectively connected to the transmission housing, and an eighth rotation shaft including the fourth ring gear and selectively connected to the second rotation shaft.

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 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 rotation shaft selectively connected to a transmission housing, a second rotation shaft, a third rotation shaft selectively connected to the transmission housing, a fourth rotation shaft directly connected to the input shaft, a fifth rotation shaft, a sixth rotation shaft selectively connected to the second and fourth rotation shafts, a seventh rotation shaft selectively connected the second rotation shaft, an eighth rotation shaft selectively connected to the seventh rotation shaft, and directly connected to the output shaft, and six friction elements disposed to selectively connect the rotation shafts and selectively connect the rotation shafts with the transmission housing.

Abstract: A planetary gear train of an automatic transmission for a vehicle may include an input shaft receiving power from an engine, an output shaft outputting the power changed in speed, a first planetary gear set, a second planetary gear, a third planetary gear set, a fourth planetary gear set, a first rotating shaft, a second rotating shaft, a third rotating shaft, a fourth rotating shaft selectively connected with the first rotating shaft and simultaneously selectively connected with a transmission housing, a fifth rotating shaft selectively connected with the first rotating shaft and simultaneously directly connected with the input shaft, a sixth rotating shaft selectively connected with the third rotating shaft and simultaneously selectively connected with the transmission housing, a seventh rotating shaft selectively connected with the first rotating shaft, an eighth rotating shaft directly connected with the output shaft, and six friction elements.

Abstract: A planetary gear train of an automatic transmission for a vehicle may include an input shaft receiving rotary power of an engine, an output shaft outputting the rotary power with rotary speed changed, a first planetary gear set, a second planetary gear set, a third planetary gear set, a fourth planetary gear set, a first rotating shaft operating continuously as an input element by being directly connected with the input shaft, a second rotating shaft selectively connected with a transmission housing, a third rotating shaft, a fourth rotating shaft selectively connected with the transmission housing, a fifth rotating shaft selectively connected with the second rotating shaft, a sixth rotating shaft operating continuously as an output element by being directly connected with the output shaft, a seventh rotating shaft, an eighth rotating shaft selectively connected with the first, the fourth, and the seventh rotating shafts, and six friction elements.

Abstract: A planetary gear train of an automatic transmission for vehicles may include an input shaft configured to receive power of an engine, an output shaft configured to output shifted power 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 rotating shaft selectively connected to a transmission housing, a second rotating shaft, a third rotating shaft selectively connected to the transmission housing, a fourth rotating shaft directly connected to the input shaft to be continuously operated as an input element, a fifth rotating shaft, a sixth rotating shaft, a seventh rotating shaft selectively connected to the input shaft simultaneously with being selectively connected to the fifth and sixth rotating shafts, an eighth rotating shaft directly connected to the output shaft simultaneously with being selectively connected to the sixth rotating shaft, and six friction elements.

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 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 rotation shaft directly connected to the input shaft, a second rotation shaft selectively connected to a transmission housing, a third rotation shaft, a fourth rotation shaft, a fifth rotation shaft directly connected to the transmission housing, a sixth rotation shaft, a seventh rotation shaft selectively connected to the fourth rotation shaft, and selectively connected to the transmission housing, an eighth rotation shaft selectively connected to the third rotation shaft, and directly connected to the output shaft, and a ninth rotation shaft selectively connected to the second rotation shaft.

Abstract: A planetary gear train of an automatic transmission for vehicles may include an input shaft receiving power of an engine, an output shaft outputting shifted power 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 rotational shaft, a second rotational shaft, a third rotational shaft, a fourth rotational shaft selectively connected to the first rotational shaft and selectively connected to a transmission housing simultaneously, a fifth rotational shaft selectively connected to the first rotational shaft and directly connected to the input shaft simultaneously, a sixth rotational selectively connected to the transmission housing, a seventh rotational shaft selectively connected to the first and third rotational shafts, an eighth rotational shaft directly connected to the output shaft, and six frictional elements.

Abstract: A planetary gear train of an automatic transmission for a vehicle may include an input shaft receiving power from an engine, an output shaft outputting power changed in speed, a first planetary gear set, a second planetary gear set, a third planetary gear set, a fourth planetary gear, a first rotating shaft selectively connected with a transmission housing, a second rotating shaft, a third rotating shaft selectively connected with the transmission housing, a fourth rotating shaft directly connected with the input shaft so as to be continuously operated as an input element, a fifth rotating shaft, a sixth rotating shaft selectively connected with the first, second, and fifth rotating shafts, a seventh rotating shaft, an eighth rotating shaft selectively connected with the seventh rotating shaft and simultaneously directly connected with the output shaft, and six friction elements.

Abstract: A planetary gear train for an automatic transmission of 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, a second planetary gear set, a third planetary gear set, a fourth planetary gear set, a first rotation shaft selectively connected to a transmission housing, a second rotation shaft, a third rotation shaft selectively connected to the transmission housing, a fourth rotation shaft, directly connected to the input shaft, a fifth rotation shaft including the second ring gear and the third and fourth sun gears, a sixth rotation shaft selectively connected to the second rotation shaft, a seventh rotation shaft selectively connected to the second and fourth rotation shafts, an eighth rotation shaft selectively connected to the sixth rotation shaft, and directly connected to the output shaft; and six friction elements.

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, a second planetary gear set, a third planetary gear set, a fourth planetary gear set, a first rotation shaft selectively connected to a transmission housing, a second rotation, a third rotation shaft, a fourth rotation shaft selectively connected to the third rotation shaft, a fifth rotation shaft directly connected to the input shaft, and selectively connected to the third rotation shaft, a sixth rotation shaft, a seventh rotation shaft selectively connected to the sixth rotation shaft or the transmission housing, and an eighth rotation shaft directly connected to the output shaft, and selectively connected to the sixth rotation shaft.

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, a second planetary gear set, a third planetary gear set, a fourth planetary gear set, a first rotation shaft, a second rotation shaft directly connected to the output shaft, a third rotation shaft selectively connected to a transmission housing, a fourth rotation shaft selectively connected to the first rotation shaft, a fifth rotation shaft selectively connected to the first rotation shaft, a sixth rotation shaft, a seventh rotation shaft directly connected to the input shaft, and an eighth rotation shaft selectively connected to the first rotation shaft, the sixth rotation shaft, or the transmission housing.

Abstract: The present disclosure is a multi-stage transmission for a vehicle that has at least ten forward shifting stages and one reverse shifting stage. The multi-stage transmission has a relatively small number of parts and a simple configuration such that an engine may be operated at desired operation, thereby providing an improvement in the fuel efficiency of the vehicle, and the engine may be operated more quietly, thereby improving the quietness of the vehicle.

Abstract: A planetary gear train of an automatic transmission for vehicles may include an input shaft receiving torque of an engine, an output shaft outputting changed torque, a first planetary gear set including a first sun gear, a first planetary carrier, and a first ring gear, a second planetary gear set including a second sun gear, a second planetary carrier, and a second ring gear, a third planetary gear set including a third sun gear, a third planetary carrier, and a third ring gear, a fourth planetary gear set including a fourth sun gear, a fourth planetary carrier, and a fourth ring gear, a first rotational shaft, a second rotational shaft, a third rotational shaft, a fourth rotational shaft, a fifth rotational shaft, a sixth rotational shaft, a seventh rotational shaft, an eighth rotational shaft, and six friction elements selectively connecting the rotational shafts and the transmission housing.