A dual clutch transmission for motor vehicles has first and second input shafts, two clutches configured to selectively couple the input shafts to an engine, two intermediate shafts arranged parallel to the input shafts, gearwheel pairs of which a fixed gearwheel is arranged on one of the input shafts and a freely rotating gearwheel is arranged on one of the intermediate shafts, freely rotating output gearwheels arranged on each of the two intermediate shafts and meshing with a differential wheel, and coupling devices configured to selectively couple the freely rotating gearwheels to the respective intermediate shaft, of which at least the coupling devices for the output gearwheels are of double acting design. A dual clutch transmission of this kind makes a large number of gears possible without significantly increasing the dimensions of the transmission or the weight thereof.

A dual clutch transmission for motor vehicles has first and second input shafts, two clutches selectively coupling the input shafts the engine, two intermediate shafts arranged parallel to the transmission input shafts, gearwheel pairs configured to transmit power between the input shafts and the intermediate shafts, and output gearwheels arranged on each of the two intermediate shafts. The output gearwheels mesh with the differential wheel and are selectively coupled to the respective intermediate shaft by one of the coupling devices. An additional intermediate gearwheel set is provided, that one gearwheel of the intermediate gearwheel set is seated on the first or second intermediate shaft, that the other gearwheel of the inter-mediate wheel set is arranged on a third intermediate shaft, and that a third output gearwheel, which meshes with one of the output gearwheels of the first or second intermediate shaft, is seated on the third intermediate shaft.

The present disclosure provides a planetary gear train of an automatic transmission for a vehicle. The planetary gear train may include: an input shaft receiving torque of an engine; an output shaft outputting changed 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; a fourth planetary gear set including tenth, eleventh, and twelfth rotation elements. The planetary gear train improves power delivery performance and fuel economy by achieving at least eleven forward speed stages and widening speed ratio (or gear ratio) with a reduced number of constituent elements being used, and secures linearity of step ratios.

A vehicle transmission having a housing and a main transmission which includes input and output shafts and four planetary gearsets. Each of the gearsets has sun and ring gears, a carrier which supports a planetary gearwheel. The sun gear and the carrier of the second gearset are coupled permanently to the input and output shafts, respectively. The carrier of the second gearset is permanently coupled to the carrier of the fourth gearset. The ring gear of the second gearset is permanently coupled to the ring gear of the third gearset. The carrier of the fourth gearset can be coupled, via a first shifting element, to the sun gear of the second gearset. The carrier of the third gearset can be coupled, via a second shifting element, to the housing. The sun gear of the third gearset can be coupled, via third and fourth shifting elements, to the input shaft.

The invention relates to a speed-change gearbox for a motor vehicle, provided with shiftable gearwheel sets (gears), which are arranged in a first and in a second sub-gearbox, wherein the sub-gearboxes are provided respectively with at least one input shaft and a common drive shaft and the input shaft that can be alternately activated via a power shiftable clutch. In order to achieve a functionally expanded shifting strategy, it is proposed that at least one gearwheel set can be associated with both sub-gearboxes.

A planetary gear train may include an input shaft, an output shaft, four planetary gear sets having first to twelfth rotation elements, a first shaft connected with the first rotation element and selectively connectable with a transmission housing, a second shaft interconnecting the second and fourth rotation elements, and connected with the input shaft, a third shaft interconnecting the third rotation element and the tenth rotation element, a fourth shaft connected with the fifth rotation element, a fifth shaft interconnecting the sixth and seventh rotation elements, and selectively connectable with the first shaft, a sixth shaft connected with the eighth rotation element and selectively connectable with the respective third and fourth shaft and selectively connectable with the transmission housing, a seventh shaft interconnecting the ninth and twelfth rotation elements, and selectively connectable with the transmission housing, and an eighth shaft connected with the eleventh rotation element and the output shaft.

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.

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 including a first rotation element, a second rotation element, and a third rotation element; a second planetary gear set including a fourth rotation element, a fifth rotation element, and a sixth rotation element; a third planetary gear set including a seventh rotation element, an eighth rotation element, and a ninth rotation element; and a fourth planetary gear set including tenth, eleventh, and twelfth rotation elements.

A planetary gear train of an automatic transmission for a vehicle includes: an input shaft from an engine; an output shaft; and first, second, third, and fourth planetary gear sets each including three rotating elements. The gear train also includes eight shafts for selectively connecting the planetary gear sets and the input and output shafts in various configurations to achieve at least 11 forward speeds and at least one reverse speed.

A planetary gear train of an automatic transmission for a vehicle is provided. The planetary gear train includes an input shaft receiving power of an engine and an output shaft outputting the power. Additionally, four planetary gear sets are provided. Various shafts the connect the elements of the gear sets either selectively or directly. The planetary gear set maximizes driving efficiency of the engine and improves power delivery performance and fuel consumption through the achievement of the more shift-stages of the automatic transmission