Bell Helicopter Textron Inc.

Ernest A Powell

Patrick R Tisdale

Ajay Sehgal

Cecil E Covington

Timothy Kent Ledbetter

Robert Arnold Brack

Madison K Robinson

Dharam Jithender Reddy

Norman Kuhns

Ronald Dean Rice

A helicopter main rotor blade balance weight retention system and assembly having a base plate (), at least one support post () integral with the base plate and extending out perpendicularly from the base plate, a plurality of balance weights (), a retaining nut plate (), and one or more fastening bolts () for securing the balance weights to the base plate, and the base plate to the rotor blade. The balance weights () include apertures () through which the support posts and the fastening bolts pass. The apertures through which the support posts pass are dimensioned such that the a snug fit is formed between the support posts and the balance weight; but the apertures through which the fastening bolts pass are dimensioned such that the threaded portions of the fastening bolts are not subjected to any shear loads from the balance weights due to the centrifugal force generated by the rotating rotor blades. The weight retention assembly is installed into pockets in the blade tip.

Helicopter main rotor blade balance weight retention assembly

An edge member for use on a composite flexure having an exposed edge surface. The edge member includes an innermost composite ply attached to the edge surface, an outermost composite ply attached to the innermost composite ply, and at least one interior composite ply disposed between the innermost composite ply and the outermost composite ply.

Protective edge members for composite flexures

An improved feathering flexure for a helicopter rotor system yoke includes, in transverse cross section, a relatively thin central web and six relatively thin flanges. Three flanges extend from each of the web's two edges, and the flanges lie in planes which are approximately radial relative to the neutral feathering axis of the feathering flexure. The feathering flexure is constructed of fiberglass material embedded in a polymer matrix. The web's fiberglass material in the web is bias material, that is, material whose glass fibers are oriented at plus or minus 45 degrees relative to the yoke's spanwise axis. In transverse cross section, each of the flanges includes two unidirectional belts disposed on either side of a bias pack. The glass fibers in the unidirectional belts are oriented parallel to the yoke's spanwise axis. The fiberglass material in the bias packs is bias material. Each flange's unidirectional belts taper inwardly toward its bias pack adjacent to web, thereby decreasing the thickness of the flange adjacent to the web. In addition, the portion of each flange adjacent to the web is configured to minimize torsional rigidity and shear stress resulting from twisting the feathering flexure.

Yoke for helicopter rotor systems

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Bedford, TX, United States of America

Ernest A Powell