Wire Rope Isolator Damper Assembly for Airframe Vibration

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Solution Overview

Problem

Current damper technologies for aircraft, such as those using liquid inertia vibration eliminators and electro-rheological fluids, face challenges in effectively isolating vibrations across multiple frequencies and providing efficient damping solutions for rotorcraft and vertical take-off and landing craft.

Innovation Solution

A damper assembly utilizing wire rope isolators with specific stiffness, compression/shear, and shape characteristics to isolate vibrations in two or more frequencies, attached to an airframe via fasteners, allowing for frequency isolation and vibration damping, particularly effective for rotorcraft and vertical take-off and landing craft.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If liquid inertia vibration eliminators or electro-rheological fluids are used for damping, then vibration control at specific frequencies is improved, but device complexity and system integration difficulty increase

Engineering Contradiction:
Improvevibration control effectivenessVSAvoidsystem integration complexity
Core Design Contradiction:
Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The patent replaces complex active damping systems (electro-rheological fluids, sensors, actuators) with simple passive wire rope isolators that require no power, control systems, or complex integration. The wire ropes are basic mechanical components that provide vibration isolation through their inherent elastic properties, eliminating the need for sophisticated vibration control systems while maintaining effectiveness across multiple frequencies.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

2Measurement precision

If active vibration control systems with sensors and actuators are implemented, then vibration damping precision is improved, but ease of operation and maintenance deteriorate

Engineering Contradiction:
Improvevibration detection accuracyVSAvoidsystem operation simplicity
Core Design Contradiction:
Measurement precisionVSEase of operation

Solution Approach 1:

The wire rope isolators are completely passive components that automatically provide vibration isolation without requiring external power, control systems, or active intervention. The system self-regulates based on the mechanical properties of the wire ropes, eliminating sensors, actuators, and complex control electronics while maintaining effective vibration damping across multiple frequencies.

Inventive Principle:
Principle #25Self-service

3Object-affected harmful factors

If multiple hollow members with electro-rheological fluid are used to surround rotor shaft, then vibration control at rotating frequencies is improved, but device complexity and manufacturing difficulty increase

Engineering Contradiction:
Improverotating shaft vibrationVSAvoidmanufacturing complexity
Core Design Contradiction:
Object-affected harmful factorsVSEase of manufacture

Solution Approach 1:

The patent replaces the complex multi-component electro-rheological fluid system with simple wire rope isolators that are easy to manufacture and install. The wire ropes are standard mechanical components requiring no specialized housing, fluid containment, or complex assembly procedures, significantly reducing manufacturing complexity while providing effective vibration isolation for rotating shafts.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The wire rope isolator-based damper assembly effectively reduces vibration levels across critical frequencies, providing a passive and efficient damping solution for aircraft, enhancing stability and reducing vibration-induced stress.

Implementation Method 1

one or more wire rope isolators having a first and a second portion, wherein the mass is attached to the one or more wire rope isolators and the mass is isolated from the airframe by the one or more wire rope isolators

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 2

a mass to damp the vibration of the airframe

Methodology Applied
Scientific EffectInertia: Inertia

Data Source

PatentEP3705744B1damper
Publication Date: 2021.10.20 BELL HELICOPTER TEXTRON INC
  • EP3705744B1 patent drawingFigure 1
  • EP3705744B1 patent drawingFigure 2A
  • EP3705744B1 patent drawingFigure 2B

AI summary

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.