Spring-Loaded Brush Seal for Axial Movement and Leakage Control

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Solution Overview

Problem

Current brush seal designs for gas turbine engines face difficulties in applications with both axial movement and high pressure differentials, leading to bristle blow-over and leakage across the sealing interface.

Innovation Solution

A brush seal with a spring-loaded backing plate and support structure that compresses and decompresses in response to axial translation, maintaining contact with the sealing surface and reducing bristle overhang, thereby minimizing leakage and distortion.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a brush seal is used in applications with axial movement and high pressure differentials, then the seal can handle both axial translation and pressure differential, but the bristles experience blow-over and leakage across the sealing interface

Engineering Contradiction:
Improveability to handle axial movement and pressure differentialVSAvoidsealing performance
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The backing plate is made spring-loaded to dynamically adapt to axial movements and pressure differentials. The spring mechanism allows the backing plate to compress and expand axially, maintaining continuous contact with the sealing surface while accommodating thermal expansion and translation of the seal cavity components.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The spring-loaded backing plate changes its axial position and compression state in response to varying pressure differentials and thermal conditions. This parameter change allows the seal to maintain optimal bristle contact with the sealing surface under varying operating conditions.

Inventive Principle:
Principle #35Parameter changes

2Adaptability or versatility

If the backing plate is spring-loaded to accommodate axial movement, then the seal can handle thermal expansion and translation, but the structure becomes more complex

Engineering Contradiction:
Improveability to accommodate thermal expansion and translationVSAvoidstructure complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The spring-loaded backing plate performs multiple functions simultaneously: it provides structural support for the bristles, accommodates axial movements from thermal expansion, compensates for pressure differentials, and maintains continuous contact with the sealing surface. This multi-functionality reduces the need for additional separate components.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The spring mechanism automatically adjusts the backing plate position and compression in response to changing operating conditions without external control. The spring self-regulates to maintain optimal seal contact under varying thermal and pressure conditions.

Inventive Principle:
Principle #25Self-service

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 spring-loaded support plate effectively reduces bristle deflection and leakage by maintaining continuous contact with the sealing surface, enhancing the sealing performance even under varying pressure conditions.

Implementation Method 1

a spring-loaded support plate configured to compress and decompress in response to axial translation of one or more of the engine components

Methodology Applied
Scientific EffectSpring: Spring

Implementation Method 2

the spring-loaded support plate... maintaining contact with the sealing surface

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 3

maintaining contact with the sealing surface and reducing bristle overhang, thereby minimizing leakage and distortion

Methodology Applied
Scientific EffectMechanical Force: Mechanical Force

Data Source

PatentEP3498983B1Brush seal with spring-loaded backing plate
Publication Date: 2021.09.29 RTX CORP
  • EP3498983B1 patent drawingFigure 1
  • EP3498983B1 patent drawingFigure 2
  • EP3498983B1 patent drawingFigure 3A~3B

AI summary

The present invention relates to a brush seal (116; 216; 316) for a gas turbine engine (20), comprising a backing plate (120; 320), a spring-loaded support plate (125; 225; 325) and a plurality of bristles (118; 218; 318) located over the spring-loaded support plate (125; 225; 325). The spring-loaded support plate (125; 225; 325) comprises a support bar (126; 226; 326) and a plurality of arms (124; 224; 324) extending from the support bar (126; 226; 326). The support arms (124; 224; 324) being supported by the backing plate (120; 320) are configured to apply a biasing load to the support bar (126; 226; 326). Thus, substantially the entire length of the bristles (118; 218; 318) is supported and the reduction of unsupported bristle overhang tends to limit bristle deflection, thus, reducing distortion of brush seal (116; 216; 316) and decrease leakage across the sealing interface.