Blade for reducing the drag movements of said blade, and a method of reducing such a drag movement
AssigneeEurocopter
InventorsThomas Manfredotti, Paul Cranga, Julien Guitton
Life of this patent
Estimating the term…
Abstract
A blade (10) extending longitudinally from a root (11) of the blade (10) to a free end (12) of the blade (10), the blade (10) having a resonator (13) incorporated therein to reduce the drag movements (F1, F2) of the blade (10), the resonator (13) being provided with a solid and movable heavy element (30) and with resilient retaining element (20) secured to the heavy element (30) and to the blade (10). Furthermore, the resonator (13) includes guide element (40) in which the heavy element (30) is capable of oscillating (F1′, F2′) longitudinally, the guide element (40) being arranged in a longitudinal direction (D1) of the blade.
Claims19
A blade for a rotorcraft, the blade comprising:
- a blade body extending longitudinally from a root to a free end;
- a resonator enclosed with the blade body to reduce drag forces on the blade, the resonator including:
- a guide channel having opposing completely enclosed ends and being disposed in the blade body and extending in a longitudinal direction of the blade body;
- a weighted element disposed in and movable along the guide channel;
- and
- a resilient retaining element securing the weighted element to the blade body,
- wherein the weighted element is capable of oscillating in the longitudinal direction such that movement of the weighted element reduces drag forces on the blade.
A method of reducing drag movements of a blade for a rotorcraft, the blade comprising:
- a blade body extending longitudinally from a root to a free end;
- a resonator enclosed with the blade body to reduce drag forces on the blade, the resonator including:
- a guide channel having opposing completely enclosed ends and being disposed in the blade body and extending in a longitudinal direction of the blade body;
- a weighted element disposed in and movable along the guide channel;
- and a resilient retaining element securing the weighted element to the blade body, wherein the weighted element is capable of oscillating in the longitudinal direction such that movement of the weighted element reduces drag forces on the blade, the method comprising:
- oscillating the weighted element in the longitudinal direction along the guide channel about an equilibrium position of the blade in order to create secondary Coriolis forces opposing the drag forces of the blade.
A blade for a rotorcraft, the blade comprising:
- a blade body adapted to be connected to a hub of a rotor at a first end and having a drag hinge located proximate the first end, the blade body extending longitudinally from the drag hinge to a free end;
- a resonator guide channel having opposing completely enclosed ends and being enclosed in the blade body and extending in a longitudinal direction of the blade body;
- a resonator weighted element disposed in and movable along the guide channel;
- and
- a resilient retaining element securing the weighted element to the blade body,
- wherein the weighted element is adapted to oscillate in the longitudinal direction such that movement of the weighted element counteracts drag forces, and wherein the resilient retaining element has a static stiffness great enough to prevent the weighted element from contacting an end of the guide channel during oscillation.
Dependencies are inferred from the claim text.