Integrated Anti-Rotation Piston Ring for Gas Turbine Sealing

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Solution Overview

Problem

Piston rings in gas turbine engines experience spinning or circumferential movement due to vibrations and pressure fluctuations, leading to potential damage to the ring and sealed components.

Innovation Solution

Integration of an anti-rotating feature on the piston ring, extending from its axial surface, which is received within a slot in the non-seal side rail, preventing circumferential movement by ensuring the anti-rotating feature contacts the slot, thus maintaining the ring's position and preventing damage.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If piston ring is maintained in groove by friction only, then device complexity is reduced, but piston ring stability deteriorates due to spinning and circumferential movement

Engineering Contradiction:
Improvepiston ring retention mechanismVSAvoidpiston ring positional stability
Core Design Contradiction:
Device complexityVSStability of the object's composition

Solution Approach 1:

The piston ring is segmented into a circular body and a separate anti-rotation feature that extends from the axial surface. This segmentation allows the anti-rotation feature to engage with the groove structure while the circular body maintains sealing function, preventing circumferential movement without requiring complete redesign of the piston ring

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The anti-rotation feature is nested within the groove structure, where the feature extending from the axial surface of the circular body is received within the groove. This nesting arrangement allows the anti-rotation feature to be contained within the existing groove geometry while effectively preventing spinning motion

Inventive Principle:
Principle #7Nested doll (Nesting)

2Stability of the object's composition

If anti-rotation feature is added to piston ring, then piston ring stability is improved, but device complexity increases

Engineering Contradiction:
Improvepiston ring positional stabilityVSAvoidpiston ring structure
Core Design Contradiction:
Stability of the object's compositionVSDevice complexity

Solution Approach 1:

The anti-rotation feature is integrally formed with the circular body from a single unitary member, merging the sealing function and anti-rotation function into a single integrated component. This eliminates the need for separate anti-rotation devices while maintaining positional stability

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The piston ring is designed to perform multiple functions: the circular body provides sealing while the integrated anti-rotation feature prevents circumferential movement. This multi-functionality allows a single component to address both sealing and anti-rotation requirements without requiring additional separate parts

Inventive Principle:
Principle #6Universality (Multi-functionality)

3Ease of operation

If frictional retention is used, then ease of operation is improved, but reliability deteriorates due to damage from spinning

Engineering Contradiction:
Improvepiston ring installationVSAvoidpiston ring and sealed component durability
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The anti-rotation feature provides preliminary prevention against spinning motion before damage can occur. By engaging the feature with the groove structure during installation, the design proactively counteracts the harmful spinning effect caused by vibrations and pressure fluctuations, protecting both the piston ring and sealed components

Inventive Principle:
Principle #9Preliminary anti-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

The anti-rotating feature effectively prevents spinning of the piston ring within the groove, reducing damage to both the ring and the sealed components by enhancing the frictional retention and accommodating thermal expansion.

Implementation Method 1

maintaining the ring's position and preventing damage

Methodology Applied
Scientific EffectFriction: Friction

Data Source

PatentEP4446624A1Piston ring with integrated Anti-rotation feature
Publication Date: 2024.10.16 PRATT & WHITNEY CANADA CORP
  • EP4446624A1 patent drawingFigure 1
  • EP4446624A1 patent drawingFigure 2~3
  • EP4446624A1 patent drawingFigure 4~5

AI summary

A piston ring (70) for a gas turbine engine (20) includes a circular body (71) having a rectangular cross section with overlapping open free ends (72) and an anti-rotating feature (100) extending from an axial surface (101) of the circular body (71). The anti-rotating feature (100) is integrally formed with the circular body (71) such that the circular body (71) and the anti-rotating feature (100) are formed from a single unitary member.