SMART DAMPER FOR HELICOPTER MAIN ROTORS

Dampers in the present articulated rotor systems are all completely passive devices. They are high maintenance components in which internal dynamic seals are constantly subjected to sustained high vibratory pressures and motions causing fatigue and ultimate failure. Consequently, conventional dampers are among the most expensive maintenance items on helicopters and yet have unsatisfactory reliability. All conventional approaches to improving damper reliability have failed to recognize that dampers can be substantially improved if designed as active, or semi-active, rather than passive devices. We intend to revolutionize rotor damper technology by developing smart dampers that introduce damping into the rotor ONLY when required. Damping-on-demand is the only logical answer to the basic dilemma of lead-lag damper design. Damping is critical for the safe operation of helicopters; however, large amount of damping is necessary only for a small fraction of the vehicle flight regimes and for only limited portions of the flight spectrum. Lower internal pressures may enable designs with fewer dynamic seals thus even further improving component reliability. Our innovative smart damping concept can be applied to both hydraulic and fluid-elastic devices with equal facility. We propose to develop smart main rotor dampers that exhibit markedly lower lifecycle costs compared with currently available dampers by means of actively adapting to various flight conditions. Projected annual savings to the military: $97 million.