External Damping Rings for Flexible Coupling NVH

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Solution Overview

Problem

Flexible couplings in hot exhaust gas conduits suffer from noise, vibration, and harshness (NVH) issues due to the interaction of mesh or braid sleeves with bellows, leading to potential fatigue and reduced durability in harsh environments.

Innovation Solution

The use of damping rings made from materials like compressed stainless steel mesh wire or heat-resistant polymers, placed exteriorly or under the braid between bellows convolutions, serves as a damper to mitigate NVH without restricting motion, and can be adjusted for optimal placement at critical frequency nodes.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a surrounding mesh or outer braid overwrap sleeve is used about the bellows convolutions to dampen vibrations, then dampening is provided, but the mesh sleeve engages and abrades on the bellows convolutions producing noise, vibration and harshness (NVH)

Engineering Contradiction:
Improvedampening effectivenessVSAvoidNVH
Core Design Contradiction:
ReliabilityVSObject-generated harmful factors

Solution Approach 1:

A damping ring made of resiliently elastic heat resistant material is introduced as an intermediary component between the bellows and the mesh sleeve. This damping ring absorbs vibrations and dampens NVH while preventing direct contact and abrasion between the mesh sleeve and bellows convolutions, thereby eliminating the harmful grinding noises and vibrations caused by the mesh-bellows interaction

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The invention changes the material parameter by using a resiliently elastic heat resistant material for the damping ring that can deform and absorb vibrational energy. This material property allows the damping ring to effectively dampen NVH while maintaining flexibility and resistance to high temperatures in exhaust applications

Inventive Principle:
Principle #35Parameter changes

2Object-generated harmful factors

If no surrounding mesh sleeve is used to eliminate abrasion, then NVH from abrasion is reduced, but dampening of bellows vibrations is compromised

Engineering Contradiction:
Improveabrasion noiseVSAvoidvibration dampening
Core Design Contradiction:
Object-generated harmful factorsVSReliability

Solution Approach 1:

The damping ring serves as a dedicated vibration dampening intermediary that is specifically positioned between the bellows and the external environment. It provides the necessary dampening function without requiring a surrounding mesh sleeve, thereby eliminating abrasion-related NVH while maintaining effective vibration control

Inventive Principle:
Principle #24Intermediary (Mediator)

3Reliability

If damping rings are placed exteriorly about the bellows between convolutions, then dampening is improved without restricting motion, but the bellows structure becomes more complex

Engineering Contradiction:
Improvedampening performanceVSAvoidcoupling structure
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The damping function is segmented into discrete damping rings that are positioned at specific locations between bellows convolutions rather than using a continuous surrounding mesh sleeve. This segmentation allows for targeted dampening at critical vibration nodes while maintaining simplicity and flexibility in the overall coupling structure

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The damping rings are designed to be flexible and adaptable, allowing the bellows to expand and contract freely during operation. The damping rings dynamically respond to vibrations by deforming and absorbing energy, providing effective dampening without restricting the motion capabilities of the bellows

Inventive Principle:
Principle #15Dynamics

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

This solution effectively dampens NVH without the need for external mesh sleeves, enhancing durability and maintaining motion capabilities, even in extreme conditions, by strategically locating damping rings between bellows convolutions.

Implementation Method 1

an annular, flexible, resiliently elastic damping cushion of heat resistant material is arranged between the metallic hose and the longitudinal support means

Methodology Applied
Scientific EffectMaterial damping: Damping

Implementation Method 2

an annular, flexible, resiliently elastic damping cushion of heat resistant material

Methodology Applied
Scientific EffectElasticity: Elasticity

Data Source

PatentEP3242996B1External tunable damping rings for flexible coupling
Publication Date: 2019.03.06 AMERICAN BOA INC
  • EP3242996B1 patent drawingFigure 1
  • EP3242996B1 patent drawingFigure 2~3
  • EP3242996B1 patent drawingFigure 4

AI summary

Damping rings (25) of suitable disclosed material are disposed exteriorly and between spaced apart convolutions (12, 13, 14, 15; 31, 32) of a bellows (21; 28) of a flexible coupling (10; 30). One, two or more damping rings (25) are oriented in a coupling (10; 30) between bellows convolutions (12, 13, 14, 15; 31, 32) and the convolutions (12, 13, 14, 15; 31, 32) adjacent a damping ring (25) extend radially outward of an outer periphery (25a) of the ring (25). Optional outer braids (40) are held radially outward of the damping rings (25).