Variable pitch rotor blade with double flexible retention elements

Abstract

A propulsive thrust device for an engine includes a rotor blade and a hub assembly on which the rotor blade is mounted. The rotor blade comprises an airfoil and at least two support members. A propeller thrust device includes a rotor blade, a central hub at which the rotor blade centrifugal load is supported, and an outer hub supporting a control mechanism mechanically connected to the rotor blade and controllable to vary the pitch of the rotor blade on the central hub. A rotor blade for an aircraft engine or in a separate ducted fan housing driven by a powered shaft or gearbox output shaft includes an airfoil and first and second support members attached to the airfoil. An extended arm or portion of the structure at the root of the airfoil of each blade is attached to a controllable mechanism that can vary the pitch of all blades simultaneously.

1 . A rotor blade for an aircraft engine, said rotor blade comprising:
 an airfoil;   a first support member flexibly attached to said airfoil; and   a second support member flexibly attached to said airfoil;   said first support member and said second support member being attachable to a rotatable hub and movable relative to said rotatable hub to allow a pitch of said rotor blade to be varied.   
     
     
         2 . The rotor blade of  claim 1 , wherein said rotor blade further comprises a pivot point about which said rotor blade is pivotal about a rotor blade axis extending axially through said rotor blade. 
     
     
         3 . The rotor blade of  claim 2 , wherein said rotor blade is pivotal via independent axial rotation of a first portion of said hub assembly to which said first support member is attached relative to a second portion of said hub assembly to which said second support member is attached. 
     
     
         4 . The rotor blade of  claim 1 , wherein said airfoil comprises a root through which said first support member and said second support member extend, said root being rotatable on said hub via a bearing. 
     
     
         5 . The rotor blade of  claim 1 , wherein said first support member and said second support member are attachable to said rotatable hub using a preloadable pin.