Piston Seal Ring Bypass Channels for Uniform Turbine Sealing Heat

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Solution Overview

Problem

Existing piston seal rings (PSRs) in gas turbine engines face challenges with non-axisymmetric leakage, leading to local thermal hotspots and reduced sealing performance due to manufacturing difficulties and limited structural integrity.

Innovation Solution

The implementation of bypass flow channels around the PSR, extending between opposite axial sides, forms a symmetric leak path, trading some sealing effectiveness for uniform thermal behavior and reducing structural risk by avoiding bypass slots or channels within the PSR.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If bypass flow channels are integrated into the PSR structure, then sealing performance is improved, but manufacturing complexity and structural risk increase

Engineering Contradiction:
Improvesealing performanceVSAvoidmanufacturing complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The seal system is divided into two independent parts: the PSR provides axial sealing while the rotor element provides radial sealing through integrated bypass flow channels. This segmentation allows each component to be optimized independently, reducing manufacturing complexity while maintaining overall sealing performance.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The bypass flow channels act as an intermediary structure within the rotor element that mediates between the PSR and the sealing requirement. By placing the channels in the rotor element rather than the PSR, the design reduces structural risk to the seal ring while achieving the desired flow control.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Temperature

If bypass flow channels are added to control thermal responses, then thermal uniformity is improved, but device complexity increases

Engineering Contradiction:
Improvethermal uniformityVSAvoiddevice complexity
Core Design Contradiction:
TemperatureVSDevice complexity

Solution Approach 1:

The bypass flow channels are merged with the rotor element structure rather than being separate components. This integration achieves thermal uniformity through the flow channels while avoiding additional device complexity that would result from separate thermal management components.

Inventive Principle:
Principle #5Merging (Combining)

3Reliability

If PSR maintains tight sealing contact, then sealing effectiveness is improved, but thermal hotspots occur due to non-axisymmetric leakage

Engineering Contradiction:
Improvesealing effectivenessVSAvoidthermal hotspots
Core Design Contradiction:
ReliabilityVSTemperature

Solution Approach 1:

The bypass flow channels are strategically positioned and angled within the rotor element to create controlled asymmetric flow paths that result in axisymmetric thermal distribution. This deliberate asymmetry in channel placement compensates for the asymmetric leakage patterns, distributing heat uniformly and eliminating thermal hotspots while maintaining sealing effectiveness.

Inventive Principle:
Principle #4Asymmetry

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 solution effectively controls thermal responses in an axi-symmetric manner, reducing manufacturability challenges and structural risks while maintaining engine performance and part durability.

Implementation Method 1

The second rotor element is formed to define bypass flow channels about the PSR that extend between opposite axial sides of the PSR

Methodology Applied
Scientific EffectFluid flow:

Data Source

PatentEP4553273A1Piston seal ring with flow bypass
Publication Date: 2025.05.14 RTX CORP
  • EP4553273A1 patent drawingFigure 1
  • EP4553273A1 patent drawingFigure 2
  • EP4553273A1 patent drawingFigure 3

AI summary

A gas turbine engine (20) is provided and includes a first rotor element (410) defining a groove, a second rotor element (420) disposed to rotate about the first rotor element (410) and a piston seal ring (PSR) (430) disposed in the groove to form a seal between the first rotor element (410) and the second rotor element (420). The second rotor element (420) is formed to define bypass flow channels (422) about the PSR (430) that extend between opposite axial sides (432, 433) of the PSR (430).