Dual higher harmonic control (HHC) for a counter-rotating, coaxial rotor system
AssigneeSikorsky Aircraft Corporation
InventorWilliam A. Welsh
Life of this patent
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Abstract
A dual, counter-rotating, coaxial rotor system provides individual control of an upper rotor system and a lower rotor system. The lower rotor control system and the upper rotor control system provide six controls or “knobs” to minimize or theoretically eliminate airframe vibration. In a dual, counter-rotating, coaxial rotor system, application of a HHC system to the two rotor systems individually but located on the common axis, will yield essentially complete vibration reduction because the 6 controls will suppress the 6 loads.
Claims10
A rotary-wing aircraft comprising:
- a dual, counter-rotating, coaxial rotor system having an upper rotor system and a lower rotor system rotatable about a common axis of rotation;
- an upper swashplate linked to said upper rotor system;
- a lower swashplate linked to said lower rotor system;
- a sensor system within an airframe;
- an upper HHC actuator system which includes at least one individually controllable actuator in each axis to control said upper swashplate and said upper rotor system in an X-Y-Z axis;
- a lower HHC actuator system which includes at least one individually controllable actuator in each axis to control said lower swashplate and said lower rotor system in an X-Y-Z axis;
- and
- a HHC controller in communication with said sensor system, said upper HHC actuator system, and said lower HHC system to individually control said upper rotor system and said lower rotor system to reduce vibration.
A method of reducing vibration in a rotary wing aircraft airframe having a dual, counter-rotating, coaxial rotor system having an upper rotor system and a lower rotor system rotatable about a common axis of rotation comprising:
- individually controlling at least one individually controllable actuator in each axis to control an upper swashplate and control an upper rotor system in an X-Y-Z axis with an upper HHC actuator system to reduce vibration within an airframe of the aircraft;
- and
- individually controlling a lower HHC actuator system which includes at least one individually controllable actuator in each axis to control a lower swashplate and control a lower rotor system in an X-Y-Z axis;
- with a lower HHC actuator system to reduce vibration within the airframe of the aircraft.
Dependencies are inferred from the claim text.