Abstract: A gear mechanism comprising at least two toothed parts accommodated in a casing, a storage tank that stores oil to be injected into each meshing zone of the at least two tooth parts, a first receptacle built into the casing for receiving oil, a second receptacle that communicates with the first receptacle into which the oil can flow from the first receptacle, the second receptacle in turn communicating with the storage tank. Oil is conveyed from the storage tank to each meshing zone at a pressure greater than the pressure prevailing in the casing, internal pressure in the casing is reduced, and oil is drained to the storage tank. The first and second receptacles have a substantially identical pressure, while the storage tank is generally maintained at atmospheric pressure. The gear mechanism operates at atmospheric pressure if the gear mechanism fails to reduce internal pressure in the casing.

Abstract: The invention concerns a gear mechanism comprising at least two toothed parts housed in a casing, each fixed to a rotary shaft in bearings integral with the casing; a tank for storing lubricating/cooling oil to be injected into each gear zone of the toothed parts; means for transporting oil from said tank to the gear zones for injection therein at a pressure higher than the pressure prevailing in the casing; means for reducing the gas pressure in the casing; means for emptying the oil, towards the storage tank.