A double clutch transmission (DCT) provides eight forward speeds and one reverse speed while minimizing the number of gear trains used for changing speed and the whole length thereof. In particular, the DCT has a simple structure using four or five gear trains and four synchro devices and is capable of providing eight forward speeds and one reverse speed while reducing the entire weight thereof. In a conventional DCT, when a gear train is added to increase the number of speed stages, the whole length thereof is increased. The provided DCT can minimize the whole length and the weight thereof, thereby reducing the manufacturing cost, the number of parts, and the fuel efficiency.

A dual clutch transmission includes a first and a second input shaft provided with a first and second input arrangement, respectively, a center shaft, a countershaft, and a first and a second primary gear step. The first and second input shaft are coaxially arranged with the center shaft and can transfer torque from the first and second input means to the countershaft via the first and the second primary gear step. The first primary gear step including a first input gearwheel and a first driven gearwheel. The first input gearwheel is rotationally fixed with the first input shaft. The first input gearwheel is arranged upon the center shaft.

A dual clutch transmission is provided with first and second coaxial input shafts, at least one mainshaft, and an output shaft that are coaxial with one another. The transmission has a countershaft offset from the first input shaft that supports seven countershaft gear elements drivably connected to respective gear elements on the first and second input shafts and the at least one mainshaft thereby forming seven forward gear meshes for the transmission. The seven forward gear meshes provide at least nine forward gear ratios for the transmission. The transmission is powershiftable between consecutive gear ratios of the at least nine gear ratios such that no torque interrupt occurs during sequential shifts.

A power transmitting apparatus may include first and second input shafts selectively receiving torque of a power source through first and second clutches, first and second output shafts disposed in parallel with the first and second input shafts, a plurality of input gears disposed on the first and second input shafts, and at least five speed gears selectively connected to the first and second output shafts through a plurality of synchronizer modules.

A dual clutch transmission is provided with first and second coaxial input shafts, at least one mainshaft, and an output shaft that are coaxial with one another. The transmission has a countershaft offset from the first input shaft that supports seven countershaft gear elements drivably connected to respective gear elements on the first and second input shafts and the at least one mainshaft thereby forming seven forward gear meshes for the transmission. The seven forward gear meshes provide at least nine forward gear ratios for the transmission. The transmission is powershiftable between consecutive gear ratios of the at least nine gear ratios such that no torque interrupt occurs during sequential shifts.

A dual-clutch transmission has two input shafts for connection to a power shift clutch, at least one countershaft offset in parallel to the input shafts, an output gearwheel designed as an idler gear and situated coaxially with respect to the countershaft, at least one gearwheel plane having an idler gear situated coaxially with respect to the countershaft, and a shifting unit having a first shift position in which the output gearwheel and the countershaft are connected to one another in a rotationally fixed manner. The shifting unit has a second shift position in which the idler gear and the output gearwheel are directly connected to one another in a rotationally fixed manner.

A transmission for a vehicle may include a first input shaft to which power may be selectively transmitted by a first clutch, a second input shaft to which power may be selectively transmitted by a second clutch, wherein the second input shaft concentrically surrounds the first input shaft, first and second output shafts disposed in parallel with the first and second input shafts, a multiplicity of shifting gears disposed in the first and second output shafts so as to be meshed with gears of the first and second input shafts to respectively form gear steps, a plurality of synchronizing devices configured to selectively couple or decouple the shifting gears to or from the first or second output shafts, and a planetary gear train configured to selectively switch a revolution direction of one of the shifting gears.

A method of controlling a dual clutch transmission, a dual clutch transmission, and a vehicle equipped with the same which can reduce the load on a clutch on a start gear side to reduce the wear thereof and therefore make the clutch replacement interval longer. There are a first input shaft to be connected to a first clutch and a second input shaft to be connected to a second clutch. A set of odd-numbered gears and a set of even-numbered gears are arranged respectively across the first input shaft and second input shaft and an output shaft. When a vehicle starts, a start gear and a support gear are synchronously engaged to the second input shaft and the first input shaft, respectively, and simultaneously connecting the first clutch and the second clutch partially (half clutch state) to the first input shaft and the second input shaft, respectively, the support gear having a gear ratio smaller than that of the start gear by one speed or higher.