Gearbox arrangement for driving coaxial contra rotating multi-bladed rotors

A gearbox arrangement for driving a first multi-bladed rotor and a coaxial second multi-bladed rotor in opposite rotational directions comprising a first epicyclic gear and a coaxial second epicyclic gear,

• the first epicyclic gear comprising a first sun gear, a plurality of first planet gears, a first annulus gear and a first carrier, the plurality of first planet gears meshing with the first sun gear, the first annulus gear meshing with the plurality of first planet gears, the plurality of first planet gears being rotatably mounted on the first carrier,
• the second epicyclic gear comprising a second sun gear, a plurality of second planet gears, a second annulus gear and a second carrier, the plurality of second planet gears meshing with the second sun gear, the second annulus gear meshing with the plurality of second planet gears, the plurality of second planet gears being rotatably mounted on the second carrier,
• a first input shaft being drivingly connected to the first epicyclic gear, a second fixed input shaft being connected to the second epicyclic gear, the second input shaft being static,
• the first epicyclic gear being drivingly connected to the first multi-bladed rotor, the second epicyclic gear being drivingly connected to the second multi-bladed rotor, the first annulus gear o the first epicyclic gear being integrally formed with the second annulus gear of the second epicyclic gear whereby the first multi-bladed rotor and the second multi-bladed rotor are driven in opposite rotational directions, said first input shaft being drivingly connected to the first sun gear, the second fixed input shaft being connected to the second sun gear, the first carrier being drivingly connected to the first multi-bladed rotor, the second carrier being drivingly connected to the second multi-bladed rotor.