BLADE PITCH VARYING MECHANISM

摘要

An apparatus for varying the pitch of propulsor blades of a gas-turbine engine by eccentrically driven gears. A first gear is coaxially coupled to one of the propulsor blades whereby angular displacement of the first gear with respect to an engine center-line causes angular displacement of the propulsor blade. A second gear is rotatably coupled to the first gear with one of the first gear and second gear being a first internal gear and the other being a first mating gear. The first internal gear is eccentrically disposed with respect to the first mating gear and has more teeth than does the first mating gear. A third gear is rigidly coupled to the second gear. A fourth gear is rigidly coupled to a rotating structure of the engine and rotatably coupled to the third gear with one of the third gear and fourth gear being a second internal gear and the other being a second mating gear. The second internal gear is eccentrically disposed with respect to the second mating gear. The blade pitch mechanism also includes a mechanism for eccentrically revolving the second and third gears with respect to the first and fourth gears respectively, whereby the first gear is angularly displaced with respect to the fourth gear.