초록 ▼

Damping of a helicopter rotor drive train, the drive train including the free turbines of a gas turbine engine propulsion system, the aircraft main and tail rotors, and associated shafts and gears, is accomplished through active modulation of the fuel flow to the engine gas generator. The fuel flow

Damping of a helicopter rotor drive train, the drive train including the free turbines of a gas turbine engine propulsion system, the aircraft main and tail rotors, and associated shafts and gears, is accomplished through active modulation of the fuel flow to the engine gas generator. The fuel flow is varied such that a transient torque will be developed by the free turbines which is opposite in phase to drive train resonances.

대표청구항 ▼

A method of damping oscillation in a helicopter rotor drive train, the drive train including a power turbine driven by the discharge of a gas generator, said method comprising the steps of: generating a signal commensurate with the speed of the power turbine; filtering the speed signal to eliminate

A method of damping oscillation in a helicopter rotor drive train, the drive train including a power turbine driven by the discharge of a gas generator, said method comprising the steps of: generating a signal commensurate with the speed of the power turbine; filtering the speed signal to eliminate variations thereof below a preselected frequency; adjusting the time constant of the filtered signal to provide a signal which is out of phase with the sensed speed variations; and modulating the flow of fuel to the gas generator as a function of the adjusted signal to cause the torque produced by the free turbine to oppose drive train speed variations above the preselected frequency.