Segmented Carbon Piston Ring Seal for Turbine Air Leakage

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Solution Overview

Problem

Current gas turbine engine seals fail to effectively prevent hot airflow from moving forward, leading to inefficiencies in thermal and propulsive performance due to wear and vibrational movements between co-rotating parts.

Innovation Solution

A rotating seal assembly with overlapping annular sections made of carbon material, featuring a radially-outer-facing sealing surface and an annular groove, which expands radially to maintain a complete seal and prevent axial leakage, using a retainer to secure the sections and accommodate thermal expansion.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional seals are used between co-rotating parts, then the structure is simple, but the seal fails to prevent hot airflow leakage due to wear and vibrational movements

Engineering Contradiction:
Improvesealing effectivenessVSAvoidseal structure complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The seal is divided into multiple independent annular sections (at least two) that can move relative to each other. Each section has its own radially-outer-facing sealing surface, allowing the seal to accommodate wear and vibrational movements while maintaining sealing effectiveness against hot airflow leakage.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The annular sections are designed to be dynamically adjustable with overlapping interfaces that allow relative movement between sections. This dynamic configuration enables the seal to adapt to wear and vibrational movements during engine operation, preventing hot airflow from moving forward past the seal.

Inventive Principle:
Principle #15Dynamics

2Adaptability or versatility

If the seal is made as a single solid piece, then manufacturing is simpler, but it cannot accommodate thermal expansion and wear during operation

Engineering Contradiction:
Improveaccommodation of thermal expansion and wearVSAvoidmanufacturing complexity
Core Design Contradiction:
Adaptability or versatilityVSEase of manufacture

Solution Approach 1:

The seal is constructed from multiple separate annular sections rather than a single solid piece. This segmentation allows each section to independently accommodate thermal expansion and wear while the overlapping interfaces maintain the complete annular seal configuration.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The seal sections are designed to change physical parameters during operation, including thermal expansion and wear accommodation. The overlapping interfaces between sections allow for parameter changes while maintaining sealing effectiveness.

Inventive Principle:
Principle #35Parameter changes

3Reliability

If the seal sections are made with overlapping interfaces, then a complete annular seal is maintained during radial expansion, but the assembly complexity increases

Engineering Contradiction:
Improvemaintainment of complete sealVSAvoidassembly complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The seal is divided into multiple annular sections with overlapping interfaces. This segmentation allows the seal to maintain a complete annular configuration during radial expansion while accommodating the complexity through modular design.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The annular sections are arranged in a nested configuration with overlapping interfaces, where each section partially overlaps with adjacent sections. This nesting approach maintains the complete seal while managing assembly complexity through a systematic overlapping pattern.

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 solution effectively contains hot airflow, reduces wear on engine components, and enhances thermal and propulsive efficiencies by maintaining a tight seal during engine operation.

Implementation Method 1

accommodate thermal expansion

Methodology Applied
Scientific EffectThermal expansion: Thermal Expansion

Data Source

PatentEP3719265B1Rotating carbon piston ring seal
Publication Date: 2022.06.01 RTX CORP
  • EP3719265B1 patent drawingFigure 1
  • EP3719265B1 patent drawingFigure 2~3
  • EP3719265B1 patent drawingFigure 4~8

AI summary

A gas turbine engine assembly includes a compressor (52) including a plurality of rotors (64), where at least one of the plurality of rotors (64) includes a radial inner sealing surface (68). A rotating shaft (50) drives rotation of the plurality of rotors (64), where the rotating shaft (50) includes an annular groove (72) proximate the radial inner sealing surface (68). A seal (74) is disposed within the annular groove (72), and the seal (74) comprises at least two annular sections (88A-F) forming a complete circumference. Each of the at least two annular sections (88A-F) are separate parts and include a radially-facing sealing surface (84) engaged to the radial inner sealing surface (68) of the rotor (64) and an annular slot (82) disposed radially inward of the radially-facing sealing surface (84). A retainer (80) is disposed within the annular slot (82) limiting radial expansion of the at least two annular sections (88A-F).