Duplex Finger Seal for High Displacement Joints

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Solution Overview

Problem

Finger seals used in industrial applications, such as turbine engines, lose sealing ability when pressure differentials reverse, as they rely on spring loading and pressure in one direction, leading to potential leakage.

Innovation Solution

A sealing apparatus comprising a resilient member with a cavity and a sealing member featuring layered finger seals that maintain contact through an interference fit and spring load, ensuring sealing effectiveness regardless of pressure direction changes, with optional high-temperature resistant materials like Nextel™ or metal fabric for enhanced performance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If finger seals rely on spring loading and pressure differentials in one direction, then sealing effectiveness is maintained under normal pressure conditions, but sealing ability is lost when pressure reverses

Engineering Contradiction:

Improvesealing effectivenessVSAvoidpressure direction adaptability

Core Design Contradiction:

ReliabilityVSAdaptability or versatility

Solution Approach 1:

The sealing member is divided into multiple discrete finger seals (typically 3-5 fingers) arranged radially around the sealing interface. Each finger can independently deflect and maintain contact with the mating surface, allowing the seal to adapt to pressure differentials from any direction while maintaining sealing effectiveness

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The finger seals are designed with spring loading mechanisms that allow dynamic deflection and adjustment. The fingers can flex and reposition themselves in response to changing pressure conditions, ensuring continuous contact with the mating surface regardless of pressure direction reversals

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

The apparatus effectively maintains sealing integrity across varying pressure conditions by distributing load uniformly across the sealing surfaces, preventing leakage and maintaining contact between the finger seals and the parts they interface with, even when pressure reverses.

Implementation Method 1

finger seals rely on spring loading and pressure differentials that occur in one direction

Methodology Applied

Scientific EffectSpring loading: Spring

Implementation Method 2

pressure differentials that occur in one direction

Methodology Applied

Scientific EffectPressure differential: Pressure Gradient

Implementation Method 3

maintain contact through an interference fit and spring load

Methodology Applied

Scientific EffectInterference fit: Mechanical Force

Data Source

PatentEP2836748B1Duplex finger seal for joints with high relative displacement

Publication Date: 2017.08.30 UNITED TECH CORP

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AI summary

The sealing apparatus and method of assembling the same is disclosed. The sealing apparatus may comprise a resilient member and a sealing member. The resilient member may define a cavity having a closed end and an open end. The resilient member may include a first wall having a first inner sealing surface and a second wall having a second inner sealing surface. The first and second walls may be joined at the closed end. The sealing member may be disposed at least partially in the cavity in sealing engagement with the first and second inner sealing surfaces. The sealing member may comprise an upper plurality of layered finger seals and a lower plurality of layered finger seals.