Stator Vane Damper Spring Radial Biasing Gas Turbine

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Solution Overview

Problem

Stator assemblies in gas turbine engines with unsupported airfoils at the inner diameter are susceptible to vibrations, which existing damping configurations fail to adequately address, particularly in configurations without inner shrouds or attachment liners.

Innovation Solution

A stator assembly design featuring first and second hooks with attachment liners and a discrete damper spring that engages the outer case and stator vanes, providing radial biasing and stabilization through a W-shaped or V-shaped spring configuration with asymmetrically oriented notches and fingers, and adhesive securing for stability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If a stator assembly uses unsupported airfoils at the inner diameter to reduce structural complexity, then device complexity is reduced, but vibration susceptibility increases

Engineering Contradiction:
Improvestructural complexityVSAvoidvibration susceptibility
Core Design Contradiction:
Device complexityVSObject-affected harmful factors

Solution Approach 1:

A damper spring is introduced as an intermediary component between the stator segment and the outer case. This spring provides damping forces to counteract vibrations of the unsupported airfoils while maintaining the simplified structural configuration without inner shrouds.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The damper spring changes the dynamic parameters of the stator assembly by providing radial biasing forces and damping coefficients. This modifies the vibration characteristics of the unsupported airfoils, reducing their susceptibility to harmful vibrations while maintaining structural simplicity.

Inventive Principle:
Principle #35Parameter changes

2Device complexity

If inner shrouds are removed to simplify the stator assembly, then device complexity is reduced, but stability and vibration damping capability deteriorate

Engineering Contradiction:
Improvestator assembly complexityVSAvoidstator segment stability
Core Design Contradiction:
Device complexityVSStability of the object's composition

Solution Approach 1:

The inner shroud is extracted (removed) from the stator assembly to reduce complexity. However, its stabilizing function is transferred to the damper spring system, which provides equivalent or superior vibration damping and stability for the stator segments.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The mechanical stabilization function previously provided by the inner shroud is replaced by a spring-based damping system. The damper spring provides radial biasing and vibration damping forces that substitute for the stabilizing effect of the removed inner shroud.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

3Device complexity

If attachment liners are not used to reduce parts quantity, then device complexity is reduced, but wear resistance and reliability deteriorate

Engineering Contradiction:
Improvenumber of partsVSAvoidwear resistance
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The damper spring is integrated with the attachment liner function, combining vibration damping and wear protection into a single component or closely coupled system. This reduces the total number of parts while maintaining both reliability and damping capability.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The damper spring system is designed to perform multiple functions: providing radial biasing forces, damping vibrations, and serving as a wear-resistant interface between the stator segment and outer case. This multi-functionality eliminates the need for separate attachment liners.

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

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 dampens vibrations and stabilizes stator segments by engaging multiple stators radially inward, enhancing the structural integrity and reducing vibration susceptibility in gas turbine engines.

Implementation Method 1

A damper spring is arranged between the stator subassembly and the outer case. The damper spring biases the stator subassembly radially inward from the outer case.

Methodology Applied
Scientific EffectSpring: Spring

Implementation Method 2

The damper spring biases the stator subassembly radially inward from the outer case to dampen vibrations.

Methodology Applied
Scientific EffectVibration damping: Damping

Data Source

PatentEP2613021B1Stator vane spring damper
Publication Date: 2015.03.04 UNITED TECH CORP
  • EP2613021B1 patent drawingFigure 1
  • EP2613021B1 patent drawingFigure 2
  • EP2613021B1 patent drawingFigure 3

AI summary

A stator subassembly (26) includes an array of circumferentially arranged stator vanes (29). A damper spring (44) is provided between the array and an outer case (28), which supports the array. The damper spring (44) is configured to bias the array radially inwardly from the outer case (28).