Spherical Washer Liner Attachment

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

The existing methods for mounting ceramic matrix composite liners in gas turbine engines often result in damage due to the use of flat washers and bolt-pin connections, which do not adequately distribute the stress and secure the liners to the support structure.

Innovation Solution

The use of ceramic matrix composite liners with plural flanges and spherical washers, where the securement member extends through openings in the flanges and bracket, providing a larger contact surface area and reducing stress on the liner, and optionally utilizing self-locking bolts and nuts for adjustment and securement.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If flat washers and bolt-pin connections are used to secure the liner, then the connection method is simple, but the liner is damaged due to stress concentration

Engineering Contradiction:

Improveconnection structureVSAvoidliner integrity

Core Design Contradiction:

Device complexityVSReliability

Solution Approach 1:

The patent replaces flat washers with spherical washers that have a curved surface matching the spherical recess in the flange. This curvature allows for uniform stress distribution across the contact surface, eliminating stress concentration points that cause liner damage while maintaining connection simplicity.

Inventive Principle:

Principle #14Spheroidality (Curvature)

Solution Approach 2:

The invention changes the geometric parameters of the washer from flat (zero curvature) to spherical (positive curvature), and modifies the flange to include a spherical recess. This parameter change transforms the stress distribution pattern from concentrated to distributed, resolving the contradiction between simple connection and liner protection.

Inventive Principle:

Principle #35Parameter changes

2Ease of manufacture

If conventional flat washers are used, then the manufacturing process is simple, but stress is not adequately distributed on the liner

Engineering Contradiction:

Improvewasher fabricationVSAvoidstress distribution

Core Design Contradiction:

Ease of manufactureVSStress or pressure

Solution Approach 1:

The spherical washer design with its curved surface provides superior stress distribution compared to flat washers. The curvature allows the washer to conform to the spherical recess in the flange, distributing loads uniformly across the contact area and preventing stress concentration that could damage the liner.

Inventive Principle:

Principle #14Spheroidality (Curvature)

Solution Approach 2:

The system combines the spherical washer (typically metal) with the ceramic matrix composite liner and the spherical recess in the flange, creating a composite attachment structure that leverages the advantages of different materials to achieve both manufacturability and optimal stress distribution.

Inventive Principle:

Principle #40Composite materials

Data Source

PatentUS9638133B2Ceramic matrix composite liner attachment

Publication Date: 2017.05.02 RTX CORP

AI summary

An attachment structure and ceramic matrix composite liner combination for a gas turbine engine has a ceramic matrix composite liner including plural flanges extending away from a face of said liner. The flanges have an opening and a bracket secured to the flanges by a securement member extending through the opening in the flange, and through an opening in the bracket. The flanges are secured to the securement member through at least one washer having a spherical face facing a spherical recess in the flanges.