Servo-assisted mechanical gearbox with hydraulic actuation of the synchronizers

摘要

A servo-assisted mechanical gearbox (1) presenting: a first shaft (5); a second shaft (7); a plurality of gear pairs (10, 11), each of which mechanically couples the first shaft (5) to the second shaft (7), defines a corresponding speed and comprises a first gear (10) idly mounted on the first shaft (5) and a second gear (11) which is rigidly mounted on the second shaft (7) and permanently meshes with the first gear (10); a plurality of synchronizers (12), each of which is mounted coaxially to the first shaft (5) between two first gears (10) and is adapted to be actuated to alternatively engage the two first gears (10) to the first shaft (5); and a hydraulic actuation system (13) comprising for each synchronizer (12) a corresponding hydraulic servo-control (14), which is adapted to displace the synchronizer (12) alternatively in the two senses along the first shaft (5) and comprises two opposing chambers (17) adapted to be filled with a pressurized control fluid and a piston (18) which is slidingly mounted inside the two chambers (17) and is mechanically connected to the synchronizer (12).