Pylon Mounting Vibration Isolation via Tuned Fluid Inertia

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing vibration isolators for aircraft add weight and complexity, posing challenges in minimizing vibrations while maintaining structural integrity and payload capacity, especially in rotary wing aircraft.

Innovation Solution

A pylon mounting system with vibration isolators featuring high-capacity laminate elastomeric bearings and a piston with a conical profile, utilizing low viscosity, high-density tuning fluid to isolate vibrations by translating inertial forces, reducing the transfer of vibrations from aircraft components to the frame.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If vibration isolators are added to isolate aircraft frame from mechanical vibrations, then vibration isolation is improved, but weight and device complexity increase

Engineering Contradiction:
Improvevibration isolationVSAvoiddevice complexity
Core Design Contradiction:
Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The patent combines multiple vibration isolation mechanisms into a single integrated isolator assembly. The elastomeric bearing and tuning fluid system are merged into one compact device that provides both primary vibration isolation and tuned frequency damping, eliminating the need for separate isolator components and reducing overall system complexity.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent uses composite material structures, specifically high-capacity laminate elastomeric bearings combined with tuning fluid. This composite approach integrates the damping properties of elastomeric materials with the inertial properties of liquid, creating a multi-functional isolator that achieves superior vibration isolation without increasing device complexity.

Inventive Principle:
Principle #40Composite materials

2Object-affected harmful factors

If vibration isolators are added to isolate aircraft frame from mechanical vibrations, then vibration isolation is improved, but weight increases

Engineering Contradiction:
Improvevibration isolationVSAvoidweight
Core Design Contradiction:
Object-affected harmful factorsVSWeight of moving object

Solution Approach 1:

The patent employs a hydraulic approach by using tuning fluid within the isolator assembly. The liquid inertia vibration elimination system uses the mass and inertia of the tuning fluid to counteract vibrations, providing effective isolation while maintaining a compact, weight-efficient design compared to traditional solid isolator systems.

Inventive Principle:
Principle #29Pneumatics and hydraulics

Solution Approach 2:

The patent optimizes the physical parameters of the isolator, including the viscosity and density of the tuning fluid, and the geometric parameters of the elastomeric bearing. By carefully selecting and adjusting these parameters, the isolator achieves maximum vibration isolation effectiveness with minimum weight.

Inventive Principle:
Principle #35Parameter changes

3Object-affected harmful factors

If high-capacity laminate elastomeric bearings and tuning fluid are used, then vibration isolation effectiveness is improved, but manufacturing complexity increases

Engineering Contradiction:
Improvevibration isolation effectivenessVSAvoidmanufacturing complexity
Core Design Contradiction:
Object-affected harmful factorsVSEase of manufacture

Solution Approach 1:

The patent divides the isolator assembly into distinct functional segments: the elastomeric bearing component, the tuning fluid chamber, and the mounting interfaces. This segmentation allows each component to be manufactured and tested independently using standard industrial processes, then assembled into the final isolator, thereby reducing overall manufacturing complexity despite the advanced materials and mechanisms used.

Inventive Principle:
Principle #1Segmentation

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

Effectively reduces vibrations at a discrete frequency, minimizing weight and complexity while maintaining structural integrity and payload capacity, thus addressing the challenges faced by existing vibration isolators.

Implementation Method 1

vibration isolators featuring high-capacity laminate elastomeric bearings

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 2

high-capacity laminate elastomeric bearings

Methodology Applied
Scientific EffectViscoelasticity: Viscoelasticity

Implementation Method 3

utilizing low viscosity, high-density tuning fluid to isolate vibrations by translating inertial forces

Methodology Applied
Scientific EffectInertia: Inertia

Implementation Method 4

liquid inertia vibration elimination (LIVE) system

Methodology Applied
Scientific EffectLiquid inertia vibration elimination:

Implementation Method 5

low viscosity, high-density tuning fluid

Methodology Applied
Scientific EffectDensity:

Implementation Method 6

low viscosity, high-density tuning fluid

Methodology Applied
Scientific EffectViscosity:

Data Source

PatentEP2673530B1Pylon mounting system with vibration isolation
Publication Date: 2015.08.12 BELL HELICOPTER TEXTRON INC
  • EP2673530B1 patent drawingFigure 1
  • EP2673530B1 patent drawingFigure 2~3
  • EP2673530B1 patent drawingFigure 4

AI summary

A pylon mounting system with vibration isolation is provided. The system generally includes a housing that defines a first fluid chamber and a second fluid chamber, a fluid disposed within the fluid chambers; a piston assembly at least partially disposed within the housing, and a tuning passage defined by the piston assembly for providing fluid communication between the fluid chambers. The piston assembly has a first arm and a second arm, and each arm has a tubeform bearing for providing pitch and roll stiffness.