| 摘要 |
The invention relates to a new design of aircraft propulsion unit with contrarotating rotors of which the noise on takeoff is greatly reduced by temporarily running these rotors in corotation. This engine and the method of using it are characterized by two rotors (1) and (2) which rotate in contrary directions for cruising flight but in the same direction for takeoff, the blades (21) of the rotor (2) therefore having an altered pitch angle in order to maintain the direction of thrust. Reversing the direction in which the rotor (2) rotates is achieved by coupling the pinion (25) to the turbine (5) and to the rotor (2) using clutches (24) and (26), the direct-drive clutch (28) then being disengaged. |
