Apparatus for suppressing structure borne noises
AssigneeEurocopter Deutschland GmbH
InventorsHenning Strehlow, Peter Jaenker, Rudolf Maier
Life of this patent
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Abstract
Body or structural noise transmitted through a connector such as a strut, that connects a noise source, such as an engine, to an enclosure, such as a passenger cabin or cell of a helicopter, is suppressed by at least one piezoactuator which is excited to counteract any vibrations of the strut caused by body noise so that body noise vibrations are cancelled or at least substantially suppressed. The excitation of the piezoactuator is controlled in closed loop fashion in response to feedback signals from a sensor secured to the connector.
Claims9
A helicopter comprising a power plant having an inertia mass and forming a source of noise causing primary vibrations, a helicopter cell, at least one straight elongated strut having a first end connected to said power plant and an opposite second end connected to said helicopter cell, whereby said source of primary noise with said inertia mass is connected to said helicopter cell, at least one elongated piezoactuator secured to and positioned on said at least one straight elongated strut for introducing into said at least one straight elongated strut longitudinal, torsional and transversal secondary vibrations, a noise sensor for sensing said primary vibrations and a power source connected to said noise sensor and to said piezoactuator for exciting said piezoactuator for generating said secondary vibrations for suppressing said primary vibrations, wherein said inertia mass of said power plant is effectively used in said generating of said secondary vibrations.
Dependencies are inferred from the claim text.