Abstract: A structure and a method of constructing a root joint and blade retention mechanism of a composite airfoil of a propulsor blade is presented. The retention assembly includes an inner sleeve configured to retain a root area of the composite propulsor blade. The inner sleeve is fixedly attached to an inner surface of the root area by a resin transfer molding process. An outer sleeve is bonded to an outer surface of the composite propulsor blade after the completion of the resin transfer molding process. At least one bearing assembly is disposed within an annular groove of the outer sleeve. The bearing assembly rotatably couples the propulsor blade and the retention assembly to a hub assembly.

Abstract: A support structure for a propulsor blade includes at least one sleeve configured to support a root portion of the propulsor blade, the at least one sleeve fixedly attached to a surface of the root portion. The support structure also includes a preloading component configured to apply a residual compressive force to the at least one sleeve and the root portion of the propulsor blade, the residual compressive force configured to maintain an attachment of the at least one sleeve to the root portion. The propulsor blade and root portion may incorporate composite structural materials. The support structure and/or the preloading component increases the high cycle fatigue strength and bending capacity of blade retention assemblies (including, e.g., composite-to-metal joints) when subjected to high cycle bending loads under reduced centrifugal load conditions, thereby making further reductions in the size and weight of blade retention assemblies feasible.

Abstract: A system for providing variable pitch to a rotor blade of an aircraft engine includes a rotatable hub; at least one blade mounted on the rotatable hub; a gear mechanism operably connected to the rotatable hub; a timing ring rotatably and operably connected to the gear mechanism; and a pitch arm operably connecting the timing ring and the at least one blade mounted on the rotatable hub. In the operation of the system, the gear mechanism facilitates the rotation of the timing ring to vary the pitch of the at least one blade mounted on the rotatable hub.

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.