Double-clutch transmission for vehicles

Abstract

A double-clutch transmission includes, but is not limited to an inner input shaft and an outer input shaft that are connected to a first clutch and a second clutch respectively. A first layshaft and a second layshaft of the DCT are spaced apart and arranged in parallel to the input shafts. Gearwheels of the DCT are arranged on the first layshaft, on the second layshaft, on the inner input shaft and on the outer input shaft. The gearwheels include, but are not limited to seven gearwheel groups for providing seven sequentially increasing gears. Each of the gearwheel groups includes, but is not limited to a fixed gearwheel on one of the input shafts that meshes with an idler gearwheel on one of the layshafts. A fourth fixed gearwheel meshes with a fourth gear idler gearwheel and a sixth gear idler gearwheel. A third fixed gearwheel meshes with a third gear idler gearwheel and a fifth gear idler gearwheel.

1 . A double-clutch transmission, comprising:
 an inner input shaft and an outer input shaft, at least a portion of the inner input shaft surrounded by the outer input shaft;   a first clutch connected to the inner input shaft and a second clutch connected to the outer input shaft;   a first layshaft and a second layshaft spaced apart from the inner input shaft and outer input shaft and arranged in parallel to the inner input shaft and outer input shaft;   gearwheels arranged on the first layshaft, on the second layshaft, on the inner input shaft and on the outer input shaft, the gearwheels comprising a first gearwheel group, a second gearwheel group, a third gearwheel group, a fourth gearwheel group, a fifth gearwheel group, a sixth gearwheel group and a seventh gearwheel group for providing seven sequentially increasing forward gear output speeds,   the first gearwheel group comprising a first fixed gearwheel on the inner input shaft, meshing with a first gear idler gearwheel on one of the first layshaft or the second layshaft,   the third gearwheel group comprising a third fixed gearwheel on the inner input shaft, meshing with a third gear idler gearwheel on one of the first layshaft or the second layshaft,   the fifth gearwheel group comprising a fifth fixed gearwheel on the inner input shaft, meshing with a fifth gear idler gearwheel on one of the first layshaft or the second layshaft,   the seventh gearwheel group comprising a seventh fixed gearwheel on the inner input shaft, meshing with a seventh gear idler gearwheel on one of the first layshaft or the second layshaft,   the second gearwheel group comprising a second fixed gearwheel on the outer input shafts, meshing with a second gear idler gearwheel on one of the first layshaft or the second layshaft,   the fourth gearwheel group comprising a fourth fixed gearwheel on the outer input shafts, meshing with a fourth gear idler gearwheel on one of the first layshaft or the second layshaft,   the sixth gearwheel group comprising a sixth fixed gearwheel on the outer input shafts, meshing with a sixth gear idler gearwheel on one of the first layshaft or the second layshaft, and   each one of the gearwheel groups comprising a coupling device arranged on one of the first layshaft or the second layshaft to selectively engage one of the idler gearwheels for selecting one of the seven gears, and   the fourth fixed gearwheel further meshing with the sixth gear idler gearwheel,   wherein   the third fixed gearwheel further meshes with the fifth gear idler gearwheel.   
     
     
         2 . The double clutch transmission according to  claim 1 , further comprising
 a reverse gear idler shaft and a reverse gearwheel mounted on the reverse gear idler shaft, the reverse gearwheel meshing with one of the gearwheels on one of the layshafts for providing a reverse gear.   
     
     
         3 . The double-clutch transmission according to  claim 2 , wherein
 the first gear and the reverse gear are driven by different input shafts.   
     
     
         4 . The double-clutch transmission according to  claim 1 , further comprising
 a second reverse gearwheel on the reverse gear idler shaft, the two reverse gearwheels meshing with two of the gearwheels on the layshafts.   
     
     
         5 . The double-clutch transmission according to  claim 1 , wherein
 a distance between one of the layshafts with idler gearwheels of low gear ratios and the inner input shaft is greater than a distance between another one of the layshafts with the idler gearwheels of high gear ratios and the inner input shaft.   
     
     
         6 . The double-clutch transmission according to  claim 1  further comprising
 a park-lock gearwheel fixed onto one of the layshafts that has a pinion for providing a park-lock. 
 
     
     
         7 . The double-clutch transmission according to  claim 1 , wherein
 at least two of the first gear idler gearwheel, the second gear idler gearwheel, the third gear idler gearwheel and the fourth gear idler gearwheel are mounted on the same layshaft.   
     
     
         8 . The double-clutch transmission according to  claim 7 , wherein
 the first gear idler gearwheel, the second gear idler gearwheel, the third gear idler gearwheel and the fourth gear idler gearwheel are mounted on the same layshaft.   
     
     
         9 . The double-clutch transmission according to  claim 1 , wherein
 at least two of the fifth gear idler gearwheel, the sixth gear idler gearwheel and the seventh gear idler gearwheel are mounted on the same layshaft.   
     
     
         10 . The double-clutch transmission according to  claim 9 , wherein
 the fifth gear idler gearwheel, the sixth gear idler gearwheel and the seventh gear idler gearwheel are mounted on the same layshaft.   
     
     
         11 . The double-clutch transmission according to  claim 8 , wherein
 the first gear idler gearwheel, the second gear idler gearwheel, the third gear idler gearwheel and the fourth gear idler gearwheel are mounted on one of the layshafts, and wherein   the fifth gear idler gearwheel, the sixth gear idler gearwheel and the seventh gear idler gearwheel are mounted on the other layshaft.   
     
     
         12 . The double-clutch transmission according to  claim 1 , further comprising
 bearings for supporting the layshafts, at least two of the bearings being provided next to the first gear idler gearwheel and the second gear idler gearwheel.   
     
     
         13 . The double-clutch transmission according to  claim 1 , wherein
 the third gearwheel group and the fifth gearwheel group are driven by the inner input shaft, and the fourth gearwheel group and the sixth gearwheel groups are driven by the outer input shaft.   
     
     
         14 . The double-clutch transmission according to  claim 8 , wherein
 the third gear idler gearwheel and the fourth gear idler gearwheel are provided between the first gear idler gearwheel and the second gear idler gearwheel.   
     
     
         15 . The double-clutch transmission according to  claim 1 , further comprising
 at least two pinions that are provided on the two layshafts respectively, each of the two pinions being next to a bearing for support.   
     
     
         16 . A gearbox, comprising:
 an inner input shaft and an outer input shaft, at least a portion of the inner input shaft surrounded by the outer input shaft;   a first clutch connected to the inner input shaft and a second clutch connected to the outer input shaft;   a first layshaft and a second layshaft spaced apart from the inner input shaft and outer input shaft and arranged in parallel to the inner input shaft and outer input shaft;   gearwheels arranged on the first layshaft, on the second layshaft, on the inner input shaft and on the outer input shaft, the gearwheels comprising a first gearwheel group, a second gearwheel group, a third gearwheel group, a fourth gearwheel group, a fifth gearwheel group, a sixth gearwheel group and a seventh gearwheel group for providing seven sequentially increasing forward gear output speeds,   the first gearwheel group comprising a first fixed gearwheel on the inner input shaft, meshing with a first gear idler gearwheel on one of the first layshaft or the second layshaft,   the third gearwheel group comprising a third fixed gearwheel on the inner input shaft, meshing with a third gear idler gearwheel on one of the first layshaft or the second layshaft,   the fifth gearwheel group comprising a fifth fixed gearwheel on the inner input shaft, meshing with a fifth gear idler gearwheel on one of the first layshaft or the second layshaft,   the seventh gearwheel group comprising a seventh fixed gearwheel on the inner input shaft, meshing with a seventh gear idler gearwheel on one of the first layshaft or the second layshaft,   the second gearwheel group comprising a second fixed gearwheel on the outer input shafts, meshing with a second gear idler gearwheel on one of the first layshaft or the second layshaft,   the fourth gearwheel group comprising a fourth fixed gearwheel on the outer input shafts, meshing with a fourth gear idler gearwheel on one of the first layshaft or the second layshaft,   the sixth gearwheel group comprising a sixth fixed gearwheel on the outer input shafts, meshing with a sixth gear idler gearwheel on one of the first layshaft or the second layshaft, and   each one of the gearwheel groups comprising a coupling device arranged on one of the first layshaft or the second layshaft to selectively engage one of the idler gearwheels for selecting one of the seven gears, and   the fourth fixed gearwheel further meshing with the sixth gear idler gearwheel,   wherein the third fixed gearwheel further meshes with the fifth gear idler gearwheel; and   an output gearwheel that is adapted to separately mesh with the two pinions for providing an output torque.   
     
     
         17 . The power train device according to  claim 16 , the power train device comprising
 at least one power source for generating a driving torque.   
     
     
         18 . The power train device of  claim 17 , wherein
 the power source comprises a combustion engine.   
     
     
         19 . The power train device of  claim 17 , wherein
 the power source comprises an electric motor.   
     
     
         20 . (canceled)