Abstract: A planetary gear train of an automatic transmission for a vehicle may include an input shaft configured to receive torque of an engine and an output shaft configured to output torque. The planetary gear train further includes a plurality of planetary gear sets comprising rotation elements, a first plurality of shafts connected to one of the rotation elements of the plurality of planetary gear sets, and a second plurality of shafts. Each of which is selectively connected to a transmission housing and fixedly connected to one of the rotation elements of the plurality of planetary gear sets that is not fixedly connected with any of the first plurality of shafts.

Abstract: A power transmission apparatus for a vehicle having an engine and a motor/generator includes: a first input shaft selectively connected with a motor/generator; second and third input shafts disposed coaxially with the first input shaft, and selectively connected with the motor/generator; a torque mediating shaft disposed coaxially with the second input shaft; an intermediate shaft in parallel with the first input shaft; an idle shaft in parallel with the first input shaft, and selectively connected with a transmission housing; a first shifting section including four gear sets, receiving torque through the first and second input shafts, and providing intermediate shift-stages; and a second shifting section including a planetary gear set, forming an output torque by combination of torques from the first shifting section and the third input shaft, and outputting the output torque to the output shaft.

Abstract: A power transmission apparatus for a vehicle may include a first input shaft directly connected with a motor/generator, second and third input shafts and torque mediating shaft coaxial and selectively connected with the first input shaft, a first intermediate shaft and first and second idle shafts in parallel with the first input shaft, a second intermediate shaft in parallel with the first input shaft, and selectively connected with a transmission housing, an output shaft in parallel with the first input shaft, and coaxial and selectively connected with the second intermediate shaft, a first shifting section including six gear sets, selectively receiving torque through the first and third input shafts, and outputting intermediate shift-stages, and a second shifting section including a planetary gear set, forming an output torque by combination torques from the first shifting section and the second input shaft, and outputting the output torque to the output shaft.

Abstract: A power transmission apparatus for a vehicle may include: first, second, and third input shafts disposed coaxially with each other and each selectively connected with a motor/generator; a torque mediating shaft disposed coaxially with the first input shaft; a first intermediate shaft in parallel with the first input shaft; a second intermediate shaft in parallel with the first input shaft, and selectively connected with a transmission housing; a first shifting section including five gear sets, selectively receiving torques through the first and third input shafts, and providing intermediate shift-stages; and a second shifting section including a planetary gear set, forming an output torque by combination of torques from the first shifting section and the second input shaft, and outputting the output torque to the output shaft through one gear set.

Abstract: A power transmission apparatus for a vehicle having an engine and a motor/generator includes first to third input shafts each selectively connected with a motor shaft. A power mediating shaft is coaxially disposed with the first input shaft, and first and second intermediate shafts each are disposed in parallel with the first input shaft. The second intermediate shaft is selectively connected with a transmission housing, and an idle shaft is disposed in parallel with the first input shaft. A first shifting section includes six gear sets disposed on the above shafts and outputs a plurality of intermediate shift-stages shifted from torques received through the first and third input shafts. A second shifting section forms an output torque by combination of torques from the first shifting section and the second input shaft, and an output shaft outputs a torque received from the first and second shifting sections.

Abstract: A power transmission apparatus for a vehicle having an engine and a motor/generator includes first to third input shafts each selectively connected with a motor shaft. A power mediating shaft is coaxially disposed with the first input shaft, and first and second intermediate shafts each are disposed in parallel with the first input shaft. The second intermediate shaft is selectively connected with a transmission housing, and an idle shaft is disposed in parallel with the first input shaft. A first shifting section includes six gear sets disposed on the above shafts and outputs a plurality of intermediate shift-stages shifted from torques received through the first and third input shafts. A second shifting section forms an output torque by combination of torques from the first shifting section and the second input shaft, and an output shaft outputs a torque received from the first and second shifting sections.

Abstract: A power transmission apparatus includes a first input shaft selectively receiving an input torque, a second input shaft coaxially disposed with the first input shaft and selectively receiving the input torque, first and second intermediate shafts selectively interconnected and disposed in parallel with the first input shaft, a torque mediating shaft coaxially disposed with the first input shaft, a preliminary shifting section receiving a torque through a first input shaft and selectively outputting a shifted torque to the second intermediate shaft, a compound shifting section including a planetary gear set having a sun gear fixedly connected with the torque mediating shaft, a planet carrier fixedly connected with the second input shaft, and a ring gear externally gear-meshed with the second intermediate shaft, and an output shaft receiving a torque received from the compound shifting section and transmitting the received torque to a differential.

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. The planetary gear train includes a first shaft connected with the third, fifth, and eighth elements and selectively connected with the input shaft, a second shaft connected with the fourth element and selectively connected with the input shaft, a third shaft connected with the ninth and twelfth elements and fixedly connected with the output shaft, and a fourth shaft connected with the first, sixth, and seventh elements, a fifth shaft fixedly connected with the eleventh element. The planetary gear train includes a plurality of additional shafts selectively connected to the transmission housing and connected to an element of the first 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 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 clutching device of an automatic transmission includes: a clutch drum connected with a first rotation element, a clutch connected with the clutch drum and also a second rotation element, and a piston unit to operate the clutch. In particular, the piston unit includes: a first piston forming a first sealed space with the first rotation element and the clutch drum and moving toward the clutch to directly press the clutch by a hydraulic pressure supplied to the first space, a second piston forming a second sealed space with the first piston and the first rotation element, a spring retainer arranged on the first rotation element and forming a third sealed space with the first and second pistons and the first rotation element, a first return spring disposed between the first and second pistons, and a second return spring disposed between the spring retainer and the second piston.

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 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, and a fourth planetary gear set having tenth, eleventh, and twelfth rotation elements. The planetary gear train may further include a first plurality of shafts each fixedly connected with at least one of the rotation elements from the first, second, third, or fourth planetary gear sets, a second plurality of shafts, each selectively connected to a transmission housing and fixedly connected to a rotation element of the first and third planetary gear sets that is not fixedly connected with any of the first plurality of shafts.

Abstract: A power delivery device configured for an automatic transmission may include a brake disposed between a rotation element connected to a brake hub and a transmission housing, and a piston device disposed corresponding to the brake and operating the brake by hydraulic pressure, wherein the power delivery device configured for an automatic transmission selectively connects the rotation element to the transmission housing by use of dual pistons.

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.