Abstract:
A vibration attenuation system for attenuating vibrations in a mast of an aircraft includes a weight attached to the mast but free to orbit about the mast. The weight can be comprised of one or more weight assemblies. Embodiments can include a single weight, or plural weight assemblies wherein each weight assembly can include a mechanical interconnecting mechanism so that each weight assembly receives feedback regarding the position and movement of one or more other weight assemblies. Each weight can be associated with a spring that urges the weight towards a neutral position. Rotation of the mast can cause the weight to orbit about the mast and self-excite such that the weight acts against the urging of the spring towards an attenuating position.
Abstract:
A vibration attenuation system for attenuating vibrations in a mast of an aircraft includes a weight attached to the mast but free to orbit about the mast. The weight can be comprised of one or more weight assemblies. Embodiments can include a single weight, or plural weight assemblies wherein each weight assembly can include a mechanical interconnecting mechanism so that each weight assembly receives feedback regarding the position and movement of one or more other weight assemblies. Each weight can be associated with a spring that urges the weight towards a neutral position. Rotation of the mast can cause the weight to orbit about the mast and self-excite such that the weight acts against the urging of the spring towards an attenuating position.
Abstract:
A method and apparatus is provided, including an actuator system that may be connected to a wing frame for controlling an active element. The actuator system may include sliding elements movable along an axis parallel to the span-wise axis of the wing. The sliding elements may be connected to fixed elements and a crank element, the crank element generally comprising a beam element and a pivot element. The beam element may be offset from the pivot element so that the crank element is rotatable about the pivot element with a negative stiffness under an external force that tends to pull the sliding elements away from the fixed elements.
Abstract:
The present invention includes a damper assembly (306), method and kit to provide dampening to an airframe comprising: a mass (310) to dampen the vibration of the airframe; one or more wire rope isolators (312a, 312b) having a first and a second portion, wherein the mass (310) is attached to the one or more wire rope isolators (312a, 312b) and the mass (310) is isolated from the airframe by the one or more wire rope isolators (312a, 312b); and a first fastener (314a) and a second fastener (316a), wherein the first fasteners (314a) attaches to the first portion of the wire rope isolator (312a) to the mass (310), and the second fastener (316a) attaches the second portion of the wire rope isolator (312a) to the airframe to dampen vibration of the airframe.
Abstract:
The present invention includes a damper assembly (306), method and kit to provide dampening to an airframe (700) comprising: a mass (310) to dampen the vibration of the airframe (700); one or more wire rope isolators (312a-d) having a first and a second portion, wherein the mass (310) is attached to the one or more wire rope isolators (312a-d) and the mass (310) is isolated from the airframe (700) by the one or more wire rope isolators (312a-d); and a first fastener (314a-d) and a second fastener (316a-d), wherein the first fasteners (314a-d) attaches the first portion of the wire rope isolator (312a-d) to the mass (310), and the second fastener (316a-d) attaches the second portion of the wire rope (312a-d) isolator to the airframe (700) to dampen vibration of the airframe (700).
Abstract:
In accordance with an embodiment of the present invention, a method of operating a rotorcraft (101) includes receiving a measured yaw rate from a yaw rate sensor or a measured lateral acceleration from a lateral acceleration sensor of the rotorcraft (101), filtering the measured yaw rate or the measured lateral acceleration using a filter to form a filtered measured yaw rate or a filtered measured lateral acceleration , and regulating a yaw rate or a lateral acceleration of the rotorcraft based on the measured yaw rate or the measured lateral acceleration. The filter includes a bandpass characteristic or a notch characteristic, and the filtering is configured to reduce lateral vibrations caused by airflow in a tail section (123) of the rotorcraft (101).
Abstract:
A method and apparatus is provided, including an actuator system that may be connected to a wing frame for controlling an active element. The actuator system may include sliding elements movable along an axis parallel to the span-wise axis of the wing. The sliding elements may be connected to fixed elements and a crank element, the crank element generally comprising a beam element and a pivot element. The beam element may be offset from the pivot element so that the crank element is rotatable about the pivot element with a negative stiffness under an external force that tends to pull the sliding elements away from the fixed elements.