Filament wound structure for use as a torque drive

Abstract

A filament wound fiber reinforced resin matrix composite structure. The structure is particularly adapted for use as a torque drive diaphragm in a rotary wing aircraft hub. The structure comprises a substantially flat diaphragm and a rim. The diaphragm has a central hole therethrough for receiving a shaft and the rim has an inward turning flange for attachment. The diaphragm has an attachment means surrounding the central hole. An alternative embodiment of the structure is a hollow disc having first and second substantially flat diaphragm sides with a rim. The sides have concentric central holes therethrough and attachment means surround the holes. The structure comprises a resin matrix, fibers wound substantially tangentially to the central hole with sufficient tension in a multiple circuit pattern to form the structure, and fibers wound with sufficient tension in an essentially circumferential manner to reinforce the rim of the structure. The structure is cured by molding with sufficient heat and temperature in a controlled cure cycle. The structure does not exhibit 'oil-canning' in that the flat diaphragm or diaphragm sides do not displace from the substantially flat uniplanar mode when subjected to varying temperatures. The spring characteristics of the structure when constrained as a torque drive remain approximately linear and buckling and snap-through are eliminated during operation.