A plastics rotor blade, particularly for a helicopter, is formed with elongate filaments or rovings forming a loop for securing to a hub pin. The loop contains a metal socket secured to an extension extending between the loop walls.

Plastics rotor blade

A composite aerodynamic blade having twin-beam spars, which blade is fabricated in two halves which are eventually joined. Each spar assembly includes a spar comprising a plurality of high tensile strength fiber members bonded together to form a fiber composite extending from substantially the blade tip to the blade root and a connecting loop inboard of the blade root end of the core. A blade cuff member, including a selectively shaped wedge member extending through the loop and bonded to the fibers thereof, includes redundant provisions for connecting the blade cuff to the rotor hub. Two such spar assemblies are bonded to opposite sides of the blade cover so that the cover carries blade torsional loads. This forms a twin-beam blade in which triple, redundant centrifugal and bending load paths are present between each of the spar assemblies and the hub. For purposes of shape stability, a central low-density core member may be bonded to the spar assembly and cover. In a modified blade, a torque-tube may envelop and be bonded to the spar assemblies and blade trailing edge pockets may be bonded thereto to form the blade cross section.

Composite aerodynamic blade with twin-beam spar

A fan blade and/or propeller blade such as found in a gas turbine engine having a dovetail former having sections of composite unidirectional wrap material wrapped about the dovetail former from the concave to the convex side of the airfoil and filling cutout spaces between dovetail sections. Layers of non-wrapped composite material are cut and tapered and attached to the front and back sides of the dovetail sections.

Dovetail attachment for composite blade and method for making

A helicopter spar root end and blade assembly for attachment to the rotaryead of the helicopter, the spar includes the root end attachment having a series of formed apertures therein generally molded from strips of fiber reinforced tapes, and which tapes are turned from their disposition at the apertures for extension outboard of the blade to enhance its structural reinforcement against fatigue and fracture. The method for forming such a spar root end and blade assembly includes the disposition of a removable form for positioning of the resin treated tapes along the intended length of the spar root and blade, simultaneously positioning fiberglass sheets into the configuration of the intended blade assembly, and then compressing die halves into position around the tape and sheet formed assembly at a pressure and temperature for a stipulated period of time until the molded assembly and its inherent resin achieves curing and setting into its final and concise form.

Method of making rotor blade root end attachment

A rotor blade formed of a fiber-reinforced plastic material is constructed for the absorption of at least one of longitudinal forces and bending forces. The interior of the blade is formed of an elongated bundle of fiber strands forming a loop intermediate its ends. The loop defines one end of the longitudinally extending blade. The bundle has two limb portions extending from the loop and forming, adjacent the loop, a transition portion followed by a neck portion and then a blade portion. A skin encloses the blade outwardly from the loop. A layer of fiber strands extends around the outer surface of the loop and between the skin and the limb portions at least in the transition portion. In the region of the loop the fiber strands extend in parallel relation with the fiber strands in the bundle, however, in the transition portion the fiber strands in the layer extend angularly across the longitudinal axis of the blade.

Brunsch Klaus Dipl-Ing

Papers

Rotor blade construction

Rotorblatt aus faserverstaerktem Kunststoff mit schlaufenartiger Blattwurzel