Back to results
US 8,944,365 B2Granted
Mission-adaptive rotor blade
AssigneeGroen Brothers Aviation, Inc.
InventorDavid L. Groen
Life of this patent
Estimating the term…
Abstract
A rotorcraft may include an airframe and a rotor connected to the airframe. The rotor may include a hub and a rotor blade connected to the hub to extend radially away therefrom. The rotor blade may include biasing fibers, oriented to increase the twist of the rotor blade in response to an increase in the speed of rotation of the rotor corresponding to a mission, task, or maneuver.
Claims16
A rotorcraft comprising:
- an airframe;
- and
- a rotor connected to the airframe and defining axial and radial directions, the rotor comprising
- a hub,
- a rotor blade connected to the hub to extend in the radial direction away therefrom, and
- the rotor blade comprising biasing fibers oriented to increase twist of the rotor blade in response to a change in rotational speed of the rotor from a first value to a second value greater than the first value;
- wherein the biasing fibers include first spiral fibers wound in a first direction around a root portion of the rotor blade and second spiral fibers wound around the a tip portion of the rotor blade in a second direction opposite to the first direction such that in response to changing in centrifugal force on the rotor blade first biasing fibers cause the root portion to twist opposite to the tip portion.
4 more elements
A rotorcraft comprising:
- an airframe;
- and
- a rotor connected to the airframe and defining axial and radial directions, the rotor comprising
- a hub,
- a rotor blade connected to the hub to extend in the radial direction away therefrom,
- the rotor blade comprising a root, tip, root portion located proximate the root, and tip portion located proximate the tip, the root portion defining a root angle of attack, the tip portion defining a tip angle of attack,
- the rotor blade comprising biasing fibers oriented to increase the root angle of attack with respect to the tip angle of attack in response to an increase in the centrifugal force acting on the rotor blade,
- a weight positioned in the tip portion such that the weight is movable within the tip portion, and
- an actuator coupled to the weights and operable to change a position of the weight within the tip portion;
- wherein the rotorcraft is configured to automatically cause the actuator to chance the position of the weight in response to a change in speed of the rotor.
7 more elements
A method comprising:
- selecting a rotorcraft comprising an airframe and a rotor, the rotor rotatably connected to the airframe and comprising a hub and a rotor blade, the rotor blade connected to the hub to extend radially away therefrom and comprising biasing fibers arranged in a spiral within the rotor blade;
- rotating the rotor with respect to the airframe at an angular velocity having a first value;
- increasing the centrifugal force acting on the rotor blade by transitioning the angular velocity of the rotor with respect to the airframe from the first value to a second value greater than the first value;
- and
- inducing automatically, by the biasing fibers in response to the increasing, greater twist in the rotor blade,
- wherein the biasing fibers comprise root-biasing fibers corresponding to a root portion and tip-biasing fibers corresponding to a tip portion,
- wherein the root-biasing fibers corresponding to a given side of the rotor blade are oriented substantially orthogonally with respect to the tip-biasing fibers corresponding to the given side.
4 more elements
Dependencies are inferred from the claim text.