US Patent 9017028 Turbine engine with contra-rotating non-ducted propellers

A turbine engine including two contrarotating unducted propellers of an upstream propeller and a downstream propeller, with a power turbine mounted axially between the two propellers, the turbine including an outer rotor constrained to rotate with the upstream propeller and an inner rotor driving rotation of an inlet shaft of a step-down gearbox, the gearbox includes an outlet shaft driving rotation of the rotor of the upstream propeller and an outlet shaft driving rotation of the downstream propeller.