Abstract: 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.

Abstract: 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.

Abstract: A planetary gear train may include an input shaft, an output shaft, first and second planetary gear sets each having three rotation elements, a first rotation shaft directly connected to one rotation element of the second planetary gear set and selectively connected to the input shaft, a second rotation shaft directly connected to one rotation element of the first planetary gear set and another rotation element of the second planetary gear set, and directly connected to the output shaft, a third rotation shaft directly connected to another rotation element of the first planetary gear set and the remaining rotation element of the second planetary gear set, and selectively connected to the input shaft and/or selectively connected to a transmission housing, and a fourth rotation shaft directly connected to the remaining rotation element of the first planetary gear set, and selectively connected to the input shaft through two paths and/or selectively connected to the transmission housing.

Abstract: A transmission for a vehicle includes first, second, third and fourth planetary gear set, and a plurality of friction members. Each planetary gear set includes three rotating elements. The friction elements selectively and operably connect the rotating elements of the planetary gear sets to control rotation of the rotating elements. The transmission improves fuel efficiency by increasing the number of gears and enhances driving stability of the vehicle using an operating point in a low RPM range of the engine.

Abstract: A multi-stage transmission for a vehicle may include an input shaft, an output shaft, first, second, third and fourth planetary gear devices disposed between the input shaft and the output shaft to transmit rotary force, each of the first, second, third and fourth planetary gear devices having three rotary elements, and at least six shifting elements connected to the rotary elements of the planetary gear devices.

Abstract: A multi-stage transmission for a vehicle may include an input shaft, an output shaft, first, second, third and fourth planetary gear devices disposed between the input shaft and the output shaft to transmit rotary force, each of the first, second, third and fourth planetary gear devices having three rotary elements, and at least six shifting elements connected to the rotary elements of the first, second, third and fourth planetary gear devices.

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 multi-stage transmission for vehicle may an input shaft, an output shafts, 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 first rotary element of the first planetary gear device is permanently connected to the input shaft, second rotary element is installed to be fixable by any one of the shifting elements, and third rotary element is permanently connected to second rotary element of the second planetary gear device.

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 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: An automotive multistage transmission may include an input shaft and an output shaft, 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 members and transmitting torque between the input shaft and the output shaft, and at least six shifting members connected to the rotary members of the planetary gear sets.

Abstract: A multi-step transmission for a vehicle may include an input shaft, an output shaft, first to fourth planetary gear devices disposed between the input shaft and the output shaft to transmit rotary force, each of the first to fourth planetary gear devices having three rotary elements, and at least six shifting elements connected to the rotary elements of the planetary gear devices.

Abstract: A multi-stage transmission for a vehicle includes an input shaft, an output shaft, first to fourth planetary gear devices each having three rotary elements and transmitting rotary forces between the input and output shafts, and at least six shifting elements connected to the rotary elements of the planetary gear devices. Of the first planetary gear device, the first rotary element is installed to be fixable by any one of the shifting elements and permanently connected to the second rotary element of the third planetary gear device and the third rotary element of the fourth planetary gear device, the second rotary element is variably connected to the third rotary element of the second planetary gear device and the third rotary element of the third planetary gear device, and the third rotary element is variably connected to the first and second rotary elements of the second planetary gear device.

Abstract: A multi-stages automatic transmission for vehicle may include first, second, third and fourth planetary gear sets each including first, second and third rotation elements, friction members including first, second, third and fourth clutches and first and second brakes, in which an input shaft may be connected to the first rotation element of the second planetary gear set and the third rotation element of the fourth planetary gear set, and an output shaft may be connected to the second rotation element of the fourth planetary gear set.

Abstract: A multi-stages automatic transmission for a vehicle may include first, second, third and fourth planetary gear sets, each including first, second and third rotation elements, respectively, and friction members including first, second, third and fourth clutches and first and second brakes.

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, 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 or the second rotational shaft, a sixth rotational shaft directly connected to the output shaft, a seventh rotational shaft selectively connected to the transmission housing, an eighth rotational shaft selectively connected to the fourth rotational shaft or the fifth rotational shaft, and six friction elements interposed between the rotational shafts, or between at least one rotational shaft and the transmission housing to connect selectively.

Abstract: A planetary gear train of an automatic transmission of a vehicle 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 planet carrier, and a first ring gear, a second planetary gear set including a second sun gear, a second planet carrier, and a second ring gear, a third planetary gear set including a third sun gear, a third planet carrier, and a third ring gear, a fourth planetary gear set including a fourth sun gear, a fourth planet carrier, and a fourth ring gear, a first rotation shaft, a second rotation shaft, a third rotation shaft, a fourth rotation shaft, a fifth rotation shaft, a sixth rotation shaft, a seventh rotation shaft, and an eighth 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 selectively connected to a transmission housing, a second rotation shaft, a third rotation shaft selectively connected to the transmission housing, a fourth rotation shaft, a fifth rotation shaft directly connected to the input shaft, a sixth rotation shaft selectively connected to the fourth rotation shaft or the fifth rotation shaft, a seventh rotation shaft selectively connected to the fourth rotation shaft, and an eighth rotation shaft directly connected to the output shaft, and selectively connected to the seventh rotation shaft.

Abstract: A multi-stage transmission for a vehicle may include an input shaft, an output shaft, a first to fourth planetary gear devices disposed between the input shaft and the output shaft to transmit rotary force, each of the first to fourth planetary gear devices 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 continuously connected to the input shaft, a second rotary element of the first planetary gear device is installed to be fixable by one shifting element of the at least six shifting elements, and a third rotary element of the first planetary gear device is continuously connected to a second rotary element of the second planetary gear device.

Abstract: A planetary gear train of an automatic transmission may include: an input shaft; an output gear; a first planetary gear set including first sun gear, first planet carrier, and first ring gear; a second planetary gear set including second sun gear, second planet carrier, and second ring gear; a third planetary gear set including third sun gear, third planet carrier, and third ring gear; a fourth planetary gear set including fourth sun gear, fourth planet carrier, and fourth ring gear; a first rotation shaft including the first sun gear; a second rotation shaft including the first planet carrier, the second ring gear, the third planet carrier, and the fourth ring gear; a third rotation shaft including the first and third ring gears; a fourth rotation shaft including the second sun gear and selectively connected to a transmission housing; a fifth rotation shaft including the second planet carrier, selectively connected to the first rotation shaft and to the third rotation shaft, and directly connected to the inp