Abstract: A planetary gear train may include: an input shaft; an output shaft; 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; four clutches, each selectively connecting at least one of the first to twelfth rotation elements to another rotation element or the input shaft; and two brakes, each selectively connectable at least one of the first to twelfth rotation elements to a transmission housing.

Abstract: A planetary gear train of an automatic transmission for a vehicle may include: an input shaft; an output shaft disposed in parallel with the input shaft; 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 first shaft fixedly connected to the first rotation element and selectively connected to the input shaft and a transmission housing; a second shaft fixedly connected to the second rotation element; a third shaft fixedly connected to the third rotation element; a fourth shaft selectively connected to the input shaft; a fifth shaft fixedly connected to the fourth rotation element and fixedly connected to the output shaft; a sixth shaft fixedly connected to the fifth rotation element; and a seventh shaft fixedly connected to the sixth rotation element, selectively connected to the fifth shaft.

Abstract: A planetary gear train includes an input shaft, an output gear, first to third planetary gear sets respectively having first to third, fourth to sixth, and seventh to ninth rotation elements, a first shaft fixedly connected to the second rotation element and the input shaft, a second shaft fixedly connected to the sixth and eighth rotation elements and the output gear, a third shaft fixedly connected to the first rotation element and a transmission housing, a fourth shaft fixedly connected to the third rotation element, a fifth shaft fixedly connected to the fourth and seventh rotation elements, a sixth shaft fixedly connected to the fifth rotation element, and a seventh shaft fixedly connected to the ninth rotation element.

Abstract: A power transmission apparatus includes: a first input shaft always receiving an input torque from an engine; second and third input shafts coaxially disposed and selectively connected with the first input shaft; a torque mediating shaft selectively connected with the first input shaft or a transmission housing; first and second intermediate shafts and an output shaft respectively disposed in parallel with the first input shaft; a first preliminary shifting section receiving a torque through a first input gear set, selectively shifting the received torque, and outputting the shifted torque; a second preliminary shifting section including a second shifting gear set which outputs a torque from the first input shaft and stops ;and a compound shifting section forming an output torque by the input torque and the first and second shifted torques.

Abstract: A power transmission apparatus includes a first input shaft receiving an input torque, second and third input shafts coaxially disposed and selectively connected with the first input shaft, first and second torque mediating shafts coaxially disposed with the first input shaft, first and second intermediate shafts and an output shaft disposed in parallel with the first input shaft, a first shifting section receiving a torque from the third input shaft and outputting a plurality of first shifted torques, a second shifting section including a first planetary gear set selectively connected with the first input shaft and outputting a plurality of second shifted torques, and a compound shifting section forming an output torque by the input torque and the first and second shifted torques.

Abstract: A power transmission apparatus for a vehicle includes: an engine output shaft; a first transmission outputting torque shifted to two shift stages to a central output shaft; and a second transmission outputting torque shifted to multiple shift stages. The second transmission includes: a first input shaft disposed on the same shaft line as that of the central output shaft; a second input shaft disposed on an outer circumference of the first input shaft a third input shaft disposed in parallel with the first and second input shafts; an idle shaft disposed in parallel with the first and second input shafts and spaced apart from the first and second input shafts; and an output shaft disposed in parallel with the first and third input shafts and the idle shaft between the first and third input shafts and the idle shaft.

Abstract: A planetary gear train may include input and output shafts a compound planetary gear set having first, second, third and fourth rotation elements by combination of first and second planetary gear sets; a third planetary gear set having fifth, sixth, and seventh rotation elements; a fourth planetary gear set having eighth, ninth, and tenth rotation elements, the first rotation element selectively connectable to the fifth rotation element and the tenth rotation element, respectively, the second rotation element and the tenth rotation element selectively connectable to the transmission housing, the third rotation element fixedly connected to the sixth rotation element, and fixedly connected to the input shaft, the fourth rotation element selectively connectable to the seventh shaft, the fifth rotation element fixedly connected to the eighth shaft, the seventh rotation element selectively connectable to the ninth shaft, the ninth rotation element fixedly connected to the output shaft.

Abstract: A planetary gear train may include input and output shafts, first to fourth planetary gear sets respectively having first to third, fourth to sixth, seventh to ninth, and tenth to twelfth elements, a first shaft connected to the second element and selectively connectable to the input shaft, a second shaft connected to the fourth element, selectively connectable to the input shaft and a transmission housing, a third shaft connected to the fifth and ninth element, selectively connectable to the input shaft and the transmission housing, a fourth shaft connected to the third and eleventh elements and the output shaft, a fifth shaft connected to the first, sixth, eighth, and tenth elements, a sixth shaft connected to the seventh element, and a seventh shaft connected to the twelfth element and selectively connectable to the transmission housing.

Abstract: A multi-stage transmission for a vehicle includes: a first planetary gear set and a second planetary gear set each including three rotating elements; a compound planetary gear set including four rotating elements; and eight rotation shafts connected to the rotating elements of the planetary gear sets.

Abstract: A power transmission apparatus includes: a first input shaft; a second input shaft coaxially disposed with the first input shaft and selectively connected with the first input shaft; a third input shaft coaxially disposed with the second input shaft and selectively connected with the first input shaft; a first output shaft in parallel with the first input shaft; a second output shaft arranged in series to and selectively connected with the first output shaft; a first shift-stage shifting section outputting two shifted torques from the third input shaft to the first output shaft; a second shift-stage shifting section outputting one shifted torque and one reverse torque from the second input shaft to the first output shaft; and a compound shifting section outputting a shifted output torque from a received torque selectively from the first input shaft or the first output shaft.

Abstract: A planetary gear train apparatus of an automatic transmission may include input and output shafts, first to fourth planetary gear sets respectively having first to third, fourth to sixth, seventh to ninth, and tenth to twelfth elements, a first shaft fixed with the third element, and selectively connectable to the input shaft, a second shaft fixed with the fourth element, and selectively connectable to the input shaft, a third shaft fixed with the eleventh element and the output shaft, a fourth shaft fixed with the first, sixth, and ninth elements, a fifth shaft fixed with the seventh and twelfth elements, and shafts, each of which is selectively connectable to a housing and fixed to an element of the first to fourth gear sets which is not fixed with of the first to fifth shafts.

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 torque; a direction changer disposed on an input shaft side and transmitting the torque of the engine to the input shaft with or without change of rotation direction, or disposed on an output shaft side and outputting the torque of the output shaft with or without change of rotation direction; a first planetary gear set including first, second and third rotation elements; a compound planetary gear set including fourth, fifth, sixth, and seventh rotation elements by combining second and third planetary gear sets; a fourth planetary gear set including eighth, ninth, and tenth rotation elements.

Abstract: A planetary gear train of an automatic transmission includes an input shaft for receiving an engine torque; an output shaft for outputting a torque; a first planetary gear set having first, second, and third rotational elements; a second planetary gear set having fourth, fifth, and sixth rotational elements; a third planetary gear set having seventh, eighth, and ninth rotational elements; and a fourth planetary gear set having tenth, eleventh, and twelfth rotational elements. The gear train further includes a first shaft and a second shaft each selectively connected with the input shaft; a third shaft fixedly connected with the output shaft; a fourth shaft fixedly connected with the first, sixth and eighth elements; a fifth shaft fixedly connected with the ninth and tenth elements; and a plurality of shafts, each selectively connected to the transmission housing and fixedly connected to one of the rotational elements of the planetary gear sets.

Abstract: A planetary gear train may include input and output shafts, first to fourth planetary gear sets respectively having first to third, fourth to sixth, seventh to ninth, and tenth to twelfth elements, a first shaft connected to the fifth and eighth elements, and selectively connectable to the input shaft, a second shaft connected to the tenth element, and selectively connectable to the input shaft, a third shaft connected to the ninth element the output shaft, a fourth shaft connected to the third and twelfth elements, a fifth shaft connected to the seventh and eleventh elements, and a plurality of shafts each selectively connecting a corresponding element to a transmission housing, the corresponding element being an element of the first and second planetary gear sets which is not interconnected.

Abstract: A planetary gear train of an automatic transmission for a vehicle may include an input shaft for receiving an engine torque, an output shaft for outputting a shifted torque, a first planetary gear set, a second planetary gear set, a third planetary gear set, a fourth planetary gear set, six control elements, a first connecting member directly connected with a transmission housing, a second connecting member selectively connectable with the transmission housing, a third connecting member selectively connectable with the input shaft, a fourth connecting member directly connected with the input shaft, a fifth connecting member selectively connectable with the transmission housing, a sixth connecting member selectively connectable with the input shaft, and selectively connectable with the transmission housing, a seventh connecting member directly connected with the output shaft, and an eighth connecting member selectively connectable with the input shaft.

Abstract: A planetary gear train may include first to third gear sets having three elements, respectively, the first and second gear sets mounted on input shaft, the third gear set mounted on output shaft, first shaft fixed to the first element and selectively connectable to the input shaft and housing, second shaft fixed to the second and sixth elements and selectively connectable to the input shaft and the housing, third shaft fixed to the third and fifth elements, fourth shaft fixed to the fourth element and selectively connectable to the housing, fifth shaft fixed to the seventh element and engaged with the third shaft, sixth shaft fixed to the eighth element and selectively connectable to the input shaft, seventh shaft fixed to the ninth element and the output shaft and selectively connectable to the fifth shaft, and two transfer gears each engaged between corresponding pair of shafts.

Abstract: A multi-stage transmission for a vehicle is provided. The multi-stage transmission includes an input shaft, an output shaft, and first, second, third, fourth and fifth planetary gear devices that are disposed between the input shaft and the output shaft to transmit rotary force. Each of the first, second, third, fourth and fifth planetary gear devices have three rotary elements, and six shifting elements that are connected to the rotary elements of the first, second, third, fourth and fifth planetary gear devices.

Abstract: A power transmission apparatus for a vehicle includes a first input shaft selectively connected with an engine output shaft through a first clutch; a second input shaft selectively connected to the engine output shaft through a second clutch; a third input shaft selectively connected to the engine output shaft through a third clutch; a power transmission shaft disposed about the external circumference of the second input shaft; first and second center shafts selectively connected with each other through a fourth clutch; an idle shaft disposed in parallel with the first input shaft; a fixed transmission for selectively shifting torque input to various shafts and outputting the torque through the second center shaft and the power transmission shaft; a composite transmission configured to complementarily composite shift and output input torque; and an output shaft outputting the torque transmitted from the composite transmission to a final reduction gear.

Abstract: A power transmission apparatus for a vehicle is disclosed. The power transmission apparatus includes three concentric input shafts, input shaft fixedly connected to an engine output shaft, a transmitting shaft disposed on the outer circumference of the first input shaft without rotation interference, a central shaft parallel to a first one of the input shafts and spaced apart from the first input shaft by a predetermined interval, a fixed transmission selectively shifting an input torque depending on the respective gear ratios of four change gear trains disposed between first and second input shafts, the transmitting shaft, and the central shaft and each having drive gears and driven gears externally connected to each other and outputting the shifted torque through the central shaft and the transmitting shaft, and composite transmission including a planetary gear set having a sun gear fixedly connected to one side of the transmitting shaft.

Abstract: A planetary gear train may include input and output shafts, first to fourth planetary gear sets respectively having first to third, fourth to sixth, seventh to tenth, and eleventh to thirteenth elements, a first shaft connected to the second element and the input shaft, a second shaft connected to the twelfth element and the output shaft, a third shaft connected to the first and seventh elements, a fourth shaft connected to the eighth element, a fifth shaft connected to the ninth and eleventh element, a sixth shaft connected to the fifth and thirteenth elements, and a plurality of shafts each selectively connecting a corresponding element to a transmission housing, the corresponding element being an element of the first, second and third planetary gear sets which is not interconnected.