Aircraft Thrust Reverser Seal Geometry for Displacement Tolerance

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Solution Overview

Problem

Aircraft engine thrust reverser seals face issues with air leakage and premature failure due to displacement of aircraft structures, leading to over-compression or under-compression, which reduces sealing effectiveness and operational life.

Innovation Solution

A seal system comprising a first seal with a circular cross-sectional shape and a second seal with a rectangular cross-sectional shape, where the second seal partially collapses to form a pocket around the first seal, increasing the contact surface area and providing a more effective seal by maintaining a tight seal over a larger range of relative displacements without becoming over-compressed.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If a single seal is used to seal the gap between thrust reverser panels, then the structure is simple, but the seal becomes over-compressed or under-compressed due to structural displacements, reducing sealing effectiveness and operational life

Engineering Contradiction:
Improveseal structureVSAvoidsealing effectiveness
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The seal system is divided into two distinct seals: a first seal (bulb seal) coupled to the first thrust reverser panel and a second seal (cup seal) coupled to the second thrust reverser panel. This segmentation allows each seal to be optimized for its specific function and to independently accommodate structural displacements, preventing both seals from being simultaneously over-compressed or under-compressed, thereby maintaining sealing effectiveness and extending operational life.

Inventive Principle:
Principle #1Segmentation

2Ease of operation

If a bulb seal is used to seal the gap between thrust reverser panels, then the seal can be installed, but it becomes over-compressed or under-compressed due to displacement of aircraft structures, leading to premature failure

Engineering Contradiction:
Improveseal installationVSAvoidoperational life
Core Design Contradiction:
Ease of operationVSDuration of action of stationary object

Solution Approach 1:

The second seal is designed with a collapsible concave portion that can dynamically adjust its shape and volume in response to compression forces. This dynamic capability allows the seal to accommodate a wider range of relative displacements between the thrust reverser panels without becoming over-compressed, thereby extending the operational life of the seal system while maintaining ease of installation.

Inventive Principle:
Principle #15Dynamics

3Adaptability or versatility

If a seal system is designed to accommodate relative displacements, then the seal can maintain effectiveness, but the contact surface area is reduced, leading to insufficient sealing force

Engineering Contradiction:
Improvedisplacement toleranceVSAvoidcontact surface area
Core Design Contradiction:
Adaptability or versatilityVSArea of stationary object

Solution Approach 1:

The second seal is designed with a concave portion that wraps around and encompasses the first seal, creating a nested configuration. This nesting arrangement increases the contact surface area between the two seals, providing sufficient sealing force and frictional engagement while allowing the system to accommodate relative displacements through the collapsible nature of the second seal.

Inventive Principle:
Principle #7Nested doll (Nesting)

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 seal system significantly increases operational life and sealing force, reducing air leakage and fire containment issues by providing a greater frictional force and being tolerant to defects and deformations, while maintaining a tight seal irrespective of structural displacements.

Implementation Method 1

The seal system significantly increases operational life and sealing force, reducing air leakage and fire containment issues by providing a greater frictional force

Methodology Applied
Scientific EffectFriction: Friction

Implementation Method 2

the second seal has a concave portion configured to at least partially collapse and wrap around at least a portion of the first seal in response to the first seal engaging the second seal

Methodology Applied
Scientific EffectElasticity: Elasticity

Data Source

PatentEP3628597B1Seal systems for use with aircraft
Publication Date: 2023.11.08 THE BOEING CO
  • EP3628597B1 patent drawingFigure 1
  • EP3628597B1 patent drawingFigure 2
  • EP3628597B1 patent drawingFigure 3

AI summary

Seal systems for aircraft (100) are disclosed. An example seal system (200) includes a first seal (412) to couple to a first thrust reverser portion (214), the first seal having a first cross-sectional shape. A second seal (414) is to couple to a second thrust reverser portion (216) opposite the first seal. The second seal having a second cross-sectional shape different than the first cross-sectional shape. The second seal is to receive at least a portion of the first seal in response to the first seal engaging the second seal.