Motor-vehicle double-clutch transmission with gear shift device comprising a rotary drum and motor-vehicle hybrid propulsion system including such a transmission

摘要

The transmission comprises a first primary shaft (12; 112) carrying driving gearwheels (20, 22, 24; 120, 122) associated to the odd gears (I, III, V) and to the reverse gear (R), a second primary shaft (14; 114) coaxial to the first one (12; 112) and carrying driving gearwheels (28, 30; 124, 130) associated to the even gears (II, IV, VI), and at least one secondary shaft (16, 18; 116, 118) carrying a plurality of idle driven gearwheels (36, 38, 40, 42, 50, 52; 136, 138, 140, 142, 150, 152) directly or indirectly meshing with the driving gearwheels (20, 22, 24, 28, 30; 120, 122, 124, 130). The gearbox (10; 110) is also provided with a gear shift device comprising a plurality of sliding engagement sleeves (44, 46, 56; 44, 46, 56, 58; 144, 146, 156, 158), each arranged to connect each time a driven gearwheel (36, 38, 40, 42, 50, 52; 136, 138, 140, 142, 150, 152) corresponding to a given gear for rotation with the respective secondary shaft (16, 18; 116, 118), a corresponding plurality of sliding shift forks (66, 68, 70, 72), each arranged to cause a respective engagement sleeve (44, 46, 56; 44, 46, 56, 58; 144, 146, 156, 158) to slide between a neutral position and at least one shift position, a rotary drum (60; 160) having on its outer cylindrical surface a corresponding plurality of guide grooves (61, 62, 63, 64; 161, 162, 163, 164) in each of which a respective stud (65, 67, 69, 71; 165, 167, 169, 171) slidably engages, which stud is rigidly connected for translation with a respective shift fork (66, 68, 70, 72) in the sliding direction of this latter, and an actuation unit arranged to cause the drum (60; 160) to rotate stepwise among a plurality of angular positions (R, R/II, N, I/II, II/III, III/IV, IV/V, IV/VI, VI; R/II, I, I/II, II/III, III/IV, IV/V, V/VI) each corresponding to predetermined positions of the engagement sleeves (44, 46, 56; 44, 46, 56, 58; 144, 146, 156, 158). The guide grooves (61, 62, 63, 64; 161, 162, 163, 164) of the drum (60; 160) are shaped in such a manner that in a first angular position (R/II) the engagement sleeves (44, 46, 56; 44, 46, 56, 58; 144, 146, 156, 158) are positioned so as to engage at the same time the second gear (II) and the reverse gear (R).