Patent ID: 8677846

Claim:
A mechanical gearbox for a motor vehicle; the gearbox comprises: a first shaft; a second shaft; a plurality of gear pairs, each of which mechanically couples the first shaft to the second shaft, defines a corresponding speed and comprises a first gear mounted on the first shaft and a second gear which is mounted on the second shaft and permanently meshes with the first gear; a plurality of synchronizers, each of which is mounted coaxially to the respective first or second shaft between two gears of two gear pairs and is adapted to be actuated to alternatively engage the two gears to the shaft, wherein for all the speeds the gear pairs of two consecutive speeds are engaged by two different synchronizers of the plurality of synchronizers; and a motorized actuation system adapted to displace each synchronizer alternatively, in two operational states, along the respective shaft, the system comprising a plurality of forks, each of which envelops a respective synchronizer, wherein the actuation system is to independently actuate the synchronizers so that each synchronizer is actuated independently from the other synchronizers, the actuation system comprising: a third shaft parallel to and by the side of the first and second shaft and supporting the forks, each of which presents an eyelet slidingly fitted along the third shaft; a plurality of circumferential cams, each of which is obtained on an external surface of the third shaft and is associated to the corresponding fork; a plurality of followers, each of which is integral with the eyelet of the respective fork and is inserted in the cam associated to the fork thereof; and a motor, which is adapted to turn the third shaft about a central rotation axis thereof; wherein the third shaft is split into two halves that are connected together by means of an elastic element and each of which supports a part of the forks.