A motor-vehicle gearbox

摘要

In a motor-vehicle transmission unit (1), the gearbox (5) comprises: two input shafts, that is, an inner shaft (11) and an outer shaft (12), carrying respective driving ring gears or gears (31-35, 37), at least two output shafts (13, 14) parallel with the input shafts (11, 12) and carrying respective driven ring gears or gears (41-45, 47), sliding sleeves (61-65) which can couple the output shafts (13, 14) with the input shafts (11, 12) in predetermined ways in order to selectively implement respective predetermined transmission ratios, and an operating rod (9) which can slide in a coaxial cavity of the inner input shaft (11) as a result of the movement of a piston (10) positioned at the end axially remote from the friction clutches of the transmission unit (1) in order to operate one of the clutches. At least one of the sliding sleeves (61-65) can bring about the selection of two non-consecutive gear ratios to permit the use of the gearbox (5) in a sequential transmission with a gear-preselection mechanism.