Piston Seal Groove Rebuild Inserts for Fretting and Gas Leakage

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Piston seal assemblies in gas turbine engines degrade over time due to fretting and wear, leading to reduced performance and potential gas leakage.

Innovation Solution

The method involves securing groove buildup members, including insert type and sectioned insert type members, into the worked seal groove to enhance retention and sealing, using materials similar to the parent material and securing them through processes like brazing or press fitting.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If piston seal assembly operates under high pressure and temperature conditions, then sealing performance is maintained, but fretting and wear occur at the seal groove leading to degradation over time

Engineering Contradiction:
Improvesealing performanceVSAvoidservice life of seal groove
Core Design Contradiction:
ReliabilityVSDuration of action of stationary object

Solution Approach 1:

The seal groove is divided into two distinct components: the original groove in the piston and a separate groove buildup member (insert) that can be independently manufactured and replaced. This segmentation allows the insert to absorb wear while the main piston structure remains intact, extending the overall service life of the seal assembly.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The groove buildup member is designed with different material properties than the original piston material, specifically using materials with superior wear resistance and fretting resistance. This parameter change in material composition allows the insert to withstand operational conditions that would otherwise degrade the original seal groove.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If groove buildup members are inserted into worked seal groove to restore sealing surface, then retention and sealing are improved, but device complexity increases due to additional components and installation steps

Engineering Contradiction:
Improveretention and sealingVSAvoidnumber of components
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The groove buildup member is designed to fit within and conform to the worked seal groove, creating a nested structure where the insert is housed within the original piston groove. This nesting approach restores the sealing surface without requiring complete redesign of the piston structure, balancing improved retention with controlled complexity.

Inventive Principle:
Principle #7Nested doll (Nesting)

3Manufacturing precision

If material is removed from piston seal assembly to prepare for insert installation, then fit for groove buildup member is improved, but structural integrity of piston is reduced

Engineering Contradiction:
Improvefit for insertVSAvoidstructural integrity of piston
Core Design Contradiction:
Manufacturing precisionVSStrength

Solution Approach 1:

The worked seal groove is prepared in advance by removing material to create precise fitment surfaces for the groove buildup member. This preliminary preparation ensures accurate positioning and secure retention of the insert while minimizing material removal to preserve the structural integrity of the remaining piston structure.

Inventive Principle:
Principle #10Preliminary action

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

This approach effectively rebuilds the piston seal assembly, improving retention and sealing performance, thereby extending the operational life of gas turbine engine components by reducing wear and fretting.

Implementation Method 1

securing them through processes like brazing or press fitting

Methodology Applied
Scientific EffectBrazing: Brazing

Implementation Method 2

securing them through processes like brazing or press fitting

Methodology Applied
Scientific EffectPress fitting: Mechanical Force

Data Source

PatentEP3916203B1Piston seal assembly guards and inserts for seal groove
Publication Date: 2024.10.02 RTX CORP
  • EP3916203B1 patent drawingFigure 1
  • EP3916203B1 patent drawingFigure 2A
  • EP3916203B1 patent drawingFigure 2B~3A

AI summary

A method of repairing a piston seal assembly (200) comprises removing worn material from a piston seal groove (204) to generate a worked seal groove (204'), applying a groove buildup member (402, 404, 406) to the worked seal groove, and disposing a seal member (210) proximate the groove buildup member.