SOFT HUB FOR BEARINGLESS ROTORS

THE ROTARY WING INDUSTRY HAS STRIVED TO DEVELOP A BEARINGLESS MAIN ROTOR (BMR), HAVING NO MECHANICAL BEARINGS. ALL TRUE BMR SYSTEMS ARE LIMITED BY THE STRENGTH IN STATIC-FATIGUE LOADS VERSUS FLAPWISE FLEXIBILITY, RESULTING IN LIMITED "G" MANEUVERS FROM A HIGHLY RESPONSIVE ROTOR SYSTEM. ATI'S SOFT HUB ROTOR CONCEPT ALLOWS TILTING OF THE ROTOR DISC MOVING THE VIRTUAL HINGE INBOARD ELIMINATING THIS UNDESIRABLE LIMITATION AND PROVIDE THE SIMPLICITY OF A TRUE BEARINGLESS MAIN ROTOR SYSTEM WITH FLAPPING ANGLES UP TO + 15 DEGREES ALLOWING THE BMR TO BE USED ON ALL ROTORCRAFT CONFIGURATIONS, EVEN TANDEM ROTORS. THE PROJECT OBJECTIVE IS TO DEVELOP A FEASIBLE "SOFT HUB" DESIGN. THE DESIGN, MANUFACTURING TECHNOLOGY, AND HUB SYSTEM ANALYSIS WILL BE CONDUCTED BASED ON UTILIZATION OF EXISTING COMPOSITE MATERIALS. VARIOUS "SOFT HUB" STIFFNESS WILL BE ANALYZED TO OBTAIN A MATCH OF MISSION REQUIREMENT AND ROTORCRAFT RESPONSE REQUIREMENT. THE "SOFT HUB" ROTOR CONCEPT HAS UNIVERSAL APPLICATIONS FOR ROTOR SYSTEMS ALLOWING CO-PLANER BMR ROTOR CONFIGURATIONS WITH 3, 4, 5, 6,AND 7 BLADES. A PHASE II PROOF OF CONCEPT SCALED WIND TUNNEL TEST WOULD PROVE THE "SOFT HUB" CAPABILITIES AND GENERATE A DATA BASE FOR FULL SCALE DESIGN. THE DEVELOPED SYSTEM COULD BE OF ENORMOUS VALUE TO MILITARY AND CIVILIAN ROTORCRAFT INDUSTRIES.