Front speaker waterproof when disassembling a modular turbojet reducer

Turbofan comprising a fan (S) driven via a fan shaft (3) carried by at least two first bearings (11, 12), a turbine shaft (4) carried by at least one second bearing (10 ) having a fixed ring (25) and a movable ring (26), said turbine shaft driving said fan shaft (3) via a rotational speed reduction device (7), said reduction device the speed of rotation and said first and second bearings being housed in a lubrication chamber (E1) consisting of fixed parts and the moving parts connected to each other by sealing means (29, 30, 31), said device reduction comprising an input wheel (27) shaped to receive the torque transmitted by said turbine shaft via drive means (8, 9) attached to said movable ring, characterized in that said drive means (8, 9) form a part movable sealing walls of the lubrication chamber (E1).