Gas Turbine Stator Vane Isolation Using Liquid Sealant

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Gas turbine engine stator vanes experience significant vibratory stress and mechanical loads due to their supporting structure, leading to high stress concentrations and material costs for durable materials like titanium and stainless steel, with existing isolation methods failing to adequately reduce these stresses.

Innovation Solution

The method involves positioning inner and outer shroud portions radially relative to each other, with stator vanes inserted into slots and mechanically isolated using a liquid sealant, such as silicone rubber, to create a flexible, bonded connection that reduces direct contact and stress on the vanes, allowing for axial and circumferential movement of shroud portions for secure fastening.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If stator vanes are mechanically supported by shrouds using rigid fastening structures, then structural strength and stability are improved, but vibratory stress and mechanical loads on the vanes increase significantly

Engineering Contradiction:
Improvestructural strengthVSAvoidvibratory stress
Core Design Contradiction:
StrengthVSStress or pressure

Solution Approach 1:

A liquid sealant is introduced as an intermediary substance between the stator vane and shroud structure. The sealant fills the interface gap and provides a compliant bonding layer that transmits minimal vibratory stress while maintaining mechanical support. This intermediary layer resolves the contradiction by decoupling the rigid support function from the rigid stress transmission path.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The mechanical support system transitions from rigid fastening to a compliant bonded connection using liquid sealant. This parameter change in the connection stiffness allows the structure to maintain strength while reducing stress transmission to the stator vanes, effectively resolving the contradiction between structural integrity and stress reduction.

Inventive Principle:
Principle #35Parameter changes

2Strength

If heavy-duty materials like titanium and stainless steel are used for stator vanes, then resistance to vibratory stress and mechanical loads is improved, but weight and material cost increase

Engineering Contradiction:
Improveresistance to vibratory stressVSAvoidvane weight
Core Design Contradiction:
StrengthVSWeight of moving object

Solution Approach 1:

The liquid sealant acts as a stress-isolating intermediary that reduces vibratory stress transmission to the stator vanes. This allows the use of lighter, less expensive materials for the vanes themselves, as the sealant protects them from the full burden of mechanical loads and vibrations that would otherwise require heavy-duty materials.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The invention enables the use of less durable, lighter materials for stator vanes by providing external stress protection through the sealant layer. The sealant absorbs the mechanical stress that would otherwise require expensive, heavy materials to withstand, allowing substitution with more economical materials.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

3Stability of the object's composition

If direct mechanical contact between stator vanes and shrouds is maintained, then structural stability is improved, but stress concentration and risk of radial movement increase

Engineering Contradiction:
Improvestructural stabilityVSAvoidstress concentration
Core Design Contradiction:
Stability of the object's compositionVSStress or pressure

Solution Approach 1:

The liquid sealant creates a controlled interface layer between the stator vane and shroud, replacing direct rigid contact with a compliant bonded connection. This intermediary layer distributes stresses uniformly across the interface, eliminating stress concentration points while maintaining structural stability through adhesive bonding.

Inventive Principle:
Principle #24Intermediary (Mediator)

4Reliability

If rigid fastening straps are used to retain stator vanes, then mechanical retention is improved, but transmission of mechanical loads and vibration to vanes worsens

Engineering Contradiction:
Improvemechanical retentionVSAvoidmechanical loads and vibration
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The rigid mechanical fastening system is replaced with a chemical bonding system using liquid sealant. This substitution changes the retention mechanism from rigid mechanical constraint to compliant adhesive bonding, maintaining reliable retention while eliminating the vibration and load transmission pathway inherent in rigid mechanical connections.

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

Solution Approach 2:

The liquid sealant serves as an intermediary bonding medium that provides mechanical retention through adhesion while isolating the stator vanes from harmful mechanical loads and vibrations. The sealant layer decouples the retention function from the stress transmission function.

Inventive Principle:
Principle #24Intermediary (Mediator)

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 configuration significantly reduces stress on stator vanes by over four times, enabling the use of lighter, less expensive materials and providing a flexible connection that accommodates imperfections, while maintaining mechanical isolation and reducing the risk of radial movement.

Implementation Method 1

bonding and supporting the ends of the vanes relative to the shrouds with the liquid sealant

Methodology Applied
Scientific EffectAdhesion: Adhesive

Implementation Method 2

The vanes are mechanically isolated from the inner and outer shrouds by applying a liquid sealant around a perimeter of the vanes and the shrouds

Methodology Applied
Scientific EffectVibration damping: Damping

Data Source

PatentEP2971578B1Method of assembling a gas turbine engine front architecture and corresponding gas turbine engine front architecture
Publication Date: 2020.05.06 RTX CORP
  • EP2971578B1 patent drawingFigure 1
  • EP2971578B1 patent drawingFigure 2~3
  • EP2971578B1 patent drawingFigure 4

AI summary

A method of assembling gas turbine engine front architecture includes positioning a first shroud and a first shroud portion radially relative to one another. Multiple vanes are arranged circumferentially between the first shroud and the first shroud portion. A second shroud portion is secured to the first shroud portion about the vanes. The first and second shroud portions provide a second shroud. The vanes are mechanically isolated from the first and second shrouds.