Sealed Structural Joint for Gas Turbine Compressor Cases

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

The existing bolted split flange connections in gas turbine engine compressor cases often lead to gas leakage and reduced structural integrity due to unsealed ends of circumferentially extending flanges, which are not bolted to the annular attachment flange.

Innovation Solution

A structural joint design that uses radially extending flanges with fasteners, including a slab head bolt and multiple fasteners, with specific pocket and aperture geometries to ensure secure and sealed connections between the non-segmented and segmented compressor cases, preventing rotation and separation during engine operation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If bolted split flanges are used to connect segmented case segments, then the compressor case can be divided into separable segments for manufacturing and assembly, but the ends of circumferentially extending flanges remain unsealed and permit gas leakage

Engineering Contradiction:
Improvecase segment separabilityVSAvoidgas seal integrity
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The patent applies segmentation by dividing the compressor case into multiple segments that can be manufactured separately and assembled together using bolted split flanges, while maintaining gas seal integrity through extended flange design

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent extends the flange structure in the radial dimension beyond the traditional bolt circle, creating an extended flange surface that provides additional sealing area. This dimensional extension allows the flange to wrap around and seal the ends of circumferentially extending flanges, preventing gas leakage while maintaining segment separability

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Ease of operation

If traditional bolted split flanges are used, then assembly is simplified, but structural integrity is reduced due to unsealed flange ends

Engineering Contradiction:
Improveassembly simplicityVSAvoidjoint structural integrity
Core Design Contradiction:
Ease of operationVSStrength

Solution Approach 1:

The extended flange structure is designed to preemptively seal the ends of circumferentially extending flanges before gas pressure can exploit gaps and cause leakage. This preliminary sealing action prevents the development of structural weaknesses that would compromise joint integrity

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP2785983B1A structural joint for connecting a first component to a segmented second component
Publication Date: 2016.04.06 UNITED TECH CORP
  • EP2785983B1 patent drawingFigure 1~5
  • EP2785983B1 patent drawingFigure 2~3
  • EP2785983B1 patent drawingFigure 4

AI summary

A structural joint includes a first flange, a second flange and a fastener with a head and a shaft. The first flange extends out from a first component to a distal first flange end. The second flange extends out from a segmented second component to a distal second flange end. The second flange includes a first lateral flange segment that extends laterally to a first flange sidewall, and a second lateral flange segment that extends laterally to a second flange sidewall, which is engaged with the first flange sidewall. The head is encased in the second flange and extends laterally into the first flange sidewall and the second flange sidewall. The shaft extends longitudinally out from the second flange and through the first flange.