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US 10,377,478 B2Granted
Thrust-generating rotor assembly
AssigneeFLIR Unmanned Aerial Systems AS
InventorsPetter Muren, Trygve Frederik Marton, Ivar Johnsrud, Päl Hagh Sandberg
Life of this patent
Estimating the term…
Abstract
The present invention discloses a rotor control system where rapid changes in rotor torque are transferred into moment forces acting about the blade pitch axis of a rotor blade in a thrust-generating rotor, to ultimately control the movements of a rotary wing aircraft. The moment forces acting on the rotor blade are transferred through a carefully adjusted damping member in order to allow rapid changes in rotor torque to create cyclic changes in blade pitch angle, while slow or permanent changes are cancelled out and affects the rotational speed and the thrust generated by the rotor, without permanently affecting the blade pitch angle of individual rotor blades.
Claims20
A thrust-generating rotor assembly comprising:
- a rotor torque assembly rotationally connected to a rotor blade assembly comprising rotor blades configured to tilt about a rotor blade axis according to a blade pitch angle;
- and
- a cyclic pitch control system comprising:
- at least one spring member connected between the rotor torque assembly and the rotor blade assembly about its axis of rotation and configured to transfer changes in rotor torque into proportional changes in rotational offset between the rotor torque assembly and the rotor blade assembly without introducing tilting moments about the rotor blade axis, and
- a rotating damping member comprising a first concentric part and a second concentric part adapted to fit together with a damper between the two parts and interact with a pitch arm to transfer the changes in rotational offset into substantial tilting moments about the rotor blade axis at rapid changes in rotor torque and to cancel or limit the tilting moments at slow or permanent changes in rotor torque, wherein the tilting moments act on at least one rotor blade to control the blade pitch angle.
2 more elements
A method of operating a thrust-generating rotor assembly comprising:
- receiving a control command to tilt a rotational plane of rotor blades for a rotor blade assembly towards a desired direction, wherein the rotor blade assembly is rotationally coupled to a rotor torque assembly for the thrust-generating rotor assembly and the rotor blades are configured to tilt about a rotor blade axis according to a blade pitch angle;
- receiving rotor blade positions from a rotor control sensor configured to indicate the rotor blade positions of the rotor blades as they rotate about a rotor shaft of the rotor torque assembly;
- and
- controlling a motor coupled to the rotor torque assembly to supply a cyclic rapid torque increase or decrease to a rotor shaft of the rotor torque assembly to generate a corresponding cyclic increase or decrease of the blade pitch angle at a desired blade position configured to generate the tilt of the rotational plane of the rotor blades towards the desired direction, based, at least in part, on the received rotor blade positions, wherein the thrust-generating rotor assembly comprises a cyclic pitch control system comprising:
- at least one spring member connected between the rotor torque assembly and the rotor blade assembly about its axis of rotation and configured to transfer changes in rotor torque into proportional changes in rotational offset between the rotor torque assembly and the rotor blade assembly without introducing tilting moments about the rotor blade axis, and
- a rotating damping member comprising a first concentric part and a second concentric part adapted to fit together with a damper between the two parts and interact with a pitch arm to transfer the changes in rotational offset into substantial tilting moments about the rotor blade axis at rapid changes in rotor torque and to cancel or limit the tilting moments at slow or permanent changes in rotor torque, wherein the tilting moments act on at least one rotor blade to control the blade pitch angle.
3 more elements
A method of assembling a thrust-generating rotor assembly comprising:
- providing a rotor blade assembly comprising rotor blades configured to tilt about a rotor blade axis according to a blade pitch angle;
- rotationally connecting a rotor torque assembly for the thrust-generating rotor assembly to the rotor blade assembly;
- and
- coupling a cyclic pitch control system to and/or between the rotor blade assembly and the rotor torque assembly, wherein the cyclic pitch control system comprises:
- at least one spring member connected between the rotor torque assembly and the rotor blade assembly about its axis of rotation and configured to transfer changes in rotor torque into proportional changes in rotational offset between the rotor torque assembly and the rotor blade assembly without introducing tilting moments about the rotor blade axis, and
- a rotating damping member comprising a first concentric part and a second concentric part adapted to fit together with a damper between the two parts and interact with a pitch arm to transfer the changes in rotational offset into substantial tilting moments about the rotor blade axis at rapid changes in rotor torque and to cancel or limit the tilting moments at slow or permanent changes in rotor torque, wherein the tilting moments act on at least one rotor blade to control the blade pitch angle.
3 more elements
Dependencies are inferred from the claim text.