| 主权项 |
1. A power transmission system for a rotorcraft, the power transmission system having at least one inlet speed-reducing gear rotating a main speed-reducing gear, the main speed-reducing gear being for connecting mechanically to a rotor mast for driving a main rotor of the rotorcraft in rotation, the main rotor contributing at least in part to providing the rotorcraft with lift, each inlet speed-reducing gear comprising at least one inlet pinion meshing with an inlet gearwheel, each inlet pinion being for driving by an engine, the main speed-reducing gear having one main gearwheel per inlet speed-reducing gear, the main speed-reducing gear having one main gearwheel meshing with each main pinion, each main pinion being connected by a respective connection shaft to a respective inlet gearwheel, wherein at least one inlet gearwheel is constrained to rotate about an axis of rotation of the inlet gearwheel of reversible connection means, the reversible connection means being designed to be able to drive a first additional drivetrain connected to an additional rotor of the rotorcraft, the first additional drivetrain being an optional member that need not be mounted on the power transmission system. |
