The Sikorsky Dynaflex Rotor - An Advanced Main Rotor System for the 1990s

A new concept for helicopter main rotor systems, under development at Sikorsky for the past several years, shows considerable promise for future applications. This rotor concept, labeled "Dynaflex", incorporates an advanced composite structure which flexes to provide a constant speed universal joint action. This allows the hub to tilt relative to the shaft, but with spring restraint. The result is a rotor which has a highly desirable equivalence to an articulated rotor, but with considerable simplification, lighter weight, and lower drag. A number of novel composite structures and fabrication techniques were utilized in the development of a successful dynamically scaled model.