Abstract: A planetary gear train is provided. The gear train includes input and output shafts and first to fourth planetary gear sets that respectively have first to third, fourth to sixth, seventh to ninth, and tenth to twelfth elements. A first shaft is connected with the first and fourth elements and selectively connected with the input shaft, a second shaft is connected with the sixth element and selectively connected with the input shaft, a third shaft is connected with the eighth element and the output shaft, a fourth shaft is connected with the second, fifth, and ninth elements, and a fifth shaft is connected with the third and eleventh elements. A plurality of shafts are each selectively connected to the transmission housing and connected to an element of the third and fourth planetary gear sets that is not connected with any of the first to seventh shafts.

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 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.

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 of an automatic transmission for a vehicle is disclosed. A planetary gear train of claim of an automatic transmission for a vehicle, includes an input shaft for receiving an external torque; an output shaft for outputting a shifted 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; a fourth planetary gear set having tenth, eleventh, and twelfth rotational elements; a first shaft fixedly connected with the second rotational element, the sixth rotational element, the seventh rotational element, and the input shaft; a second shaft fixedly connected with the eleventh rotational element, and the output shaft; and a third shaft fixedly connected with the first rotational element and the tenth rotational element.

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 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 fifth and eleventh elements, a fifth shaft connected to the eighth and tenth 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.

Abstract: A power transmission apparatus includes: a planetary gear set configured to output a reduced speed or a same speed as a rotation speed of an engine; a first input shaft selectively connected to an engine output shaft through a first clutch; a second input shaft disposed on the outer circumference of the first input shaft and selectively connected to the engine output shaft through a second clutch; a third input shaft disposed in parallel with the first input shaft; an output shaft disposed in parallel with the first input shaft; an idle shaft disposed in parallel with the first input shaft; and a fixed transmission for selectively shifting torque input according to gear ratios of four speed gear trains.

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 first, sixth, and seventh elements, and selectively connected to the input shaft, a second shaft connected to the ninth element and selectively connected to the input shaft, a third shaft connected to the eleventh element and the output shaft, a fourth shaft connected to the third and fourth elements, a fifth shaft connected to the fifth, eighth, and twelfth 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 fourth planetary gear sets which is not interconnected.

Abstract: A power transmission apparatus for a vehicle is disclosed. The power transmission apparatus includes three concentric input shafts, a transmitting shaft disposed on the peripheral circumference of a first one of the three input shafts without rotation interference, and a central shaft disposed in parallel with the first input shaft. The power transmission apparatus further includes a fixed transmission selectively shifting an input torque depending on the respective gear ratios of three change gear trains disposed between second and third input shafts, the transmitting shaft, and the central shaft. The power transmission apparatus further includes a composite transmission including one 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 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 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 planetary gear train may include: an input shaft an output shaft; first to fourth planetary gear sets including first to twelfth rotation elements; a first shaft fixedly connected to the second rotation element and the input shaft; a second shaft fixedly connected to the ninth and tenth rotation elements, and selectively connectable to the input shaft; a third shaft fixedly connected to the eleventh rotation element and the output shaft; a fourth shaft fixedly connected to the third rotation element; a fifth shaft fixedly connected to the fifth rotation element, the eighth rotation element, and the twelfth rotation element; a sixth shaft fixedly connected to the seventh rotation element; and a plurality of shafts formed by combinations of remaining rotation elements of the first and second planetary gear sets that are not connected to the first to sixth shafts, and selectively and respectively connected to a transmission housing.

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

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, first to third planetary gear sets respectively having first to third, fourth to sixth, and seventh to ninth elements, a first shaft connected to the second element and the input shaft, a second shaft connected to the sixth and eighth elements and the output shaft, a third shaft connected to the third and seventh elements, a fourth shaft connected to the fourth element, 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.

Abstract: A planetary gear train includes 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 with the fifth rotational element and the input shaft, a second shaft connected with the ninth and tenth elements, and selectively connected with the input shaft, a third shaft connected with the eleventh element and the output shaft, a fourth shaft connected with the second and twelfth elements, a fifth shaft connected with the sixth elements, a sixth shaft connected with the seventh element, a seventh shaft connected with the eighth element, 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 that is not interconnected.

Abstract: A multi-stage transmission for vehicles includes an input shaft for receiving power from an engine, an output shaft for outputting the power, a first planetary gear device, a second planetary gear device, a third planetary gear device, and a fourth planetary gear device. Each of the planetary gear devices has three rotary elements, a first rotary shaft connected to the input shaft, a second rotary shaft, a third rotary shaft, a fourth rotary shaft, a fifth rotary shaft, a sixth rotary shaft, a seventh rotary shaft, and an eighth rotary shaft connected to the third rotary element of the third planetary gear device, to the second rotary element of the fourth planetary gear device, and 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 first, sixth, and seventh elements, and selectively connected to the input shaft, a second shaft connected to the ninth element and selectively connected to the input shaft, a third shaft connected to the eleventh element and the output shaft, a fourth shaft connected to the third and fourth elements, a fifth shaft connected to the fifth, eighth, and twelfth 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 fourth planetary gear sets which is not interconnected.

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 with the ninth element and selectively connected with the input shaft, a second shaft connected with the twelfth element and selectively connected with the input shaft, a third shaft connected with the eighth and tenth elements and the output shaft, a fourth shaft connected with the first, fifth, and eleventh elements, a fifth shaft connected with the third, sixth, and seventh elements, and a plurality of additional shafts each selectively connecting a corresponding element to a transmission housing, the corresponding element being an element of the first or second planetary gear sets that is not interconnected.

Abstract: A multi-stage transmission for a vehicle, 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 provided to transfer a torque between the input shaft and the output shaft and each including three rotation elements; and seven shifting elements connected to the rotation elements of the planetary gear sets.