Rotor system vibration absorber
AssigneeBell Helicopter Textron Inc.
InventorsAjay Sehgal, Michael Smith, Frank Stamps, Bryan Marshall, Cecil Covington, Peggy Covington
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Abstract
A rotor system vibration absorber for use with a helicopter of other rotocraft is disclosed in which spring forces are provided by a plurality of elongated rods (73) arranged in a selected pattern. The rods are coupled at one end to a fixed base (79) that is coupled to a rotor hub (55), and at the other end to a tuning weight (81).
Claims31
A rotorcraft comprising:
- a fuselage;
- a drive means carried by the fuselage;
- a rotor system including a rotor hub and rotor blades, the rotor system being coupled to the drive means;
- and
- a spring-mass vibration absorber comprising:
- a base member coupled to the rotor system;
- a tuning weight;
- and
- a plurality of elongated rods disposed between the base member and the tuning weight;
- wherein the rods serve as the spring and the tuning weight serves as the mass such that vibration from the rotor system is absorbed by the oscillatory deflection of the rods and the tuning weight.
A vibration absorber for use on a rotorcraft having a rotor system including a drive means, a drive mast coupled to the drive means, a rotor hub coupled to the drive mast, and rotor blades pivotally coupled to the rotor hub, the vibration absorber comprising:
- a housing adapted for mounting to the underside of the rotor hub;
- a base member coupled to the housing;
- a tuning weight disposed above the rotor hub;
- and
- a plurality of rods, each rod being coupled at one end to the base member and coupled at the other end to the tuning weight;
- wherein the vibration absorber absorbs both vibratory hub shear forces and vibratory hub moments generated by the rotor system.
A composite spring-mass assembly comprising:
- a fixed body;
- at least one elongated composite rod attached at one end to the fixed body, the composite rod being manufactured from a unidirectional fiber reinforced pultruded composite material;
- a movable mass attached to the other end of the composite rod, such that the movable mass is cantilevered relative to the fixed body;
- wherein the spring rate of the composite spring-mass system is determined by selectively tailoring the number, arrangement, and shape of the rods.
Dependencies are inferred from the claim text.