MECHANICAL GEARBOX FOR MOTOR VEHICLES

摘要

A mechanical gearbox (1) for motor vehicles presenting: a first shaft (5); a second shaft (6); a plurality of gear pairs, each of which mechanically couples the first shaft (5) to the second shaft (6), defines a corresponding speed and comprises a first gear (7) mounted on the first shaft (5) and a second gear (8) which is mounted on the second shaft (6) and permanently meshes with the first gear (7); a plurality of synchronizers (9), each of which is mounted coaxially to a shaft (6; 5) between two gears (8; 7) of two gear pairs and is adapted to be actuated to alternatively engage the two gears (8; 7) to the shaft (6; 5); and an actuation system (10) for displacing each synchronizer (9) alternatively in the two senses along the respective shaft (6; 5) and comprising a plurality of forks (11), each of which envelops a corresponding synchronizer (9); the gear pair of two consecutive speeds are arranged so as to be engaged by two different synchronizers (9); and the actuation system (10) independently actuates the synchronizers (9).