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: Disclosed is a transmission for a vehicle that can improve fuel efficiency by implementing multiple steps of shifting and improve vehicle driving comfort by using operating points in a low RPM range of an engine. According to the transmission, since three single planetary gear sets and one compound planetary gear set are combined or five single planetary gear sets are compound and the rotary elements of the planetary gear sets and friction members are selectively connected and disconnected, their rotational speeds and directions are changed when shifting is performed. Therefore, a vehicle can be driven with the gear ratios of ten or more steps of forward shifting and one step of reverse shifting.

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 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. The four speed gear trains are disposed by externally connecting drive gears and driven gears to the first, second, and third input shafts, the output shaft, and the idle 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 an output torque, a first planetary gear set including first, second, and third rotational elements, a second planetary gear set including fourth, fifth, and sixth rotational elements, a third planetary gear set including seventh, eighth, and ninth rotational elements, and a fourth planetary gear set including tenth, eleventh, and twelfth rotational elements.

Abstract: A planetary gear train of an automatic transmission may include: an input shaft receiving torque of an engine; an output shaft transmitting torque to an output gear; 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; a fourth planetary gear set including eighth, ninth, and tenth rotation elements; a first shaft fixedly connected to the ninth rotation element and the input shaft; a second shaft fixedly connected to the second and sixth rotation elements and fixedly connected to the output shaft; a third shaft fixedly connected to the first and tenth rotation elements; a fourth shaft fixedly connected to the fourth rotation element; a fifth shaft fixedly connected to the fifth rotation element; a sixth shaft fixedly connected to the seventh rotation element; and a plurality of shafts selectively connected to a transmission housing.

Abstract: A multi-stage transmission is disclosed. The multi-stage transmission includes: two simple planetary gear sets, each including three rotary elements; one compound planetary gear set including four rotary elements; and six shifting elements. Since ten forward shifting stages and one reverse shifting stage can be accomplished with a relatively small number of parts, a simple construction and a low weight, the multi-stage transmission provides a further improved speed ratio for the driving conditions of the vehicle, thereby improving the fuel efficiency of the vehicle.

Abstract: A planetary gear train of an automatic transmission for a vehicle provides at least ten forward speeds and one reverse speed by combination of: first to fourth planetary gear sets respectively having first to third rotational elements, fourth to sixth rotational elements, seventh to ninth rotational elements, or tenth to twelfth rotational elements; first to ninth shafts; and multiple control elements including four clutches and three brakes. In particular, each of the tenth, eleventh, twelfth rotational elements is fixedly connected with a different shaft selected from the first, sixth, seventh and ninth shafts, and one clutch is fixedly connected with the ninth shaft.

Abstract: Ten or more forward speeds and two or more reverse speed are achieved by a planetary gear train of an automatic transmission that includes three planetary gear sets mounted on an input shaft, an output shaft disposed in parallel with the input shaft and having an output gear. The transmission further includes six shafts respectively interconnecting corresponding elements among the input shaft and rotational elements of the three planetary gear sets, a first transfer gear selectively delivering torque between one of the six shafts and the output shaft; and a second transfer gear selectively delivering torque between the output shaft and one rotational element of the third planetary gear set.

Abstract: A planetary gear train of an automatic transmission for a vehicle improves power delivery and fuel efficiency by applying six control elements to four planetary gear sets to achieve forward nine speed stages and one reverse speed stage. The planetary gear train includes: an input shaft; an output shaft; first to fourth first planetary gear sets each having three rotational element: four clutches and two brakes as the six control elements; and first to ninth shafts. In particular, the first shaft connects a first rotational element and the input shaft; the second shaft is connected with a second rotational element and selectively connected with the first shaft; the third shaft connects third and fifth rotational elements; the fourth shaft is connected with a fourth rotational element and fixed to a transmission housing; and the fourth shaft is connected with the fourth rotational element and fixed to the transmission housing.

Abstract: A power transmission apparatus for a vehicle is disclosed. The power transmission apparatus includes a first input shaft selectively connected to an engine output shaft through a first clutch, a second input shaft configured as a hollow shaft that is disposed on the outer circumference of the first output shaft without rotational interference and selectively connected to the engine output shaft through a second clutch, a third input shaft configured as a hollow shaft that is disposed on the outer circumference of the second output shaft without rotational interference and selectively connected to the engine output shaft through a third clutch. The transmission apparatus further comprises an output shaft placed parallel to the first, second, and third input shafts at a certain distance.

Abstract: A power transmission apparatus for a vehicle may include: a first, second, third, and fourth input shaft; an output shaft; an idle shaft; a fixed transmission performing shifts to fixed shift stages depending on gear ratios of four change gear trains; and a torque assist driving and electronic continuously variable automatic transmission performing a torque assist for a torque input from the fixed transmission and performing electric vehicle driving and electronic continuously variable automatic transmission functions to output the torque through the output shaft. The disclosed power transmission apparatus implements fixed shift stages of four forward speeds and one reverse speed in a dual clutch transmission (DCT) structure that uses three synchronizers.

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

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 thirteenth elements, a first shaft connected to the second element and the input shaft, a second shaft connected to the eleventh element and the output shaft, a third shaft connected to the first and seventh elements, a fourth shaft connected to the fifth and twelfth elements, a fifth shaft connected to the eighth and tenth elements, a sixth shaft connected to the thirteenth 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 power transmission apparatus for a vehicle may include: a first, second, third, and fourth input shaft; an output shaft; an idle shaft; a fixed transmission performing shifts to fixed shift stages depending on gear ratios of four change gear trains; and a torque assist driving and electronic continuously variable automatic transmission performing a torque assist for a torque input from the fixed transmission and performing electric vehicle driving and electronic continuously variable automatic transmission functions to output the torque through the output shaft. The disclosed power transmission apparatus implements fixed shift stages of four forward speeds and one reverse speed in a dual clutch transmission (DCT) structure that uses three synchronizers.

Abstract: A planetary gear train of an automatic transmission is disclosed to improve power delivery and fuel efficiency by applying six control elements to four planetary gear sets to achieve forward nine speed stages and one reverse speed stage. The planetary gear train includes: an input shaft; an output shaft; first to fourth planetary gear sets each having three rotational elements; four clutches and two brakes as the six control elements; and first to ninth shafts. In particular, the first shaft connects first and eleventh rotational elements, and the input shaft; the second shaft is connected with a second rotational element and selectively connected with the first shaft, the third shaft connects third and fifth rotational elements, and the fourth shaft is connected with a fourth rotational element and fixed to a transmission housing. In addition, the sixth shaft is selectively connected with the second and fifth shafts, respectively.

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 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 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.