Variable Stator Vane Alignment Projection for Gas Turbine Compressor

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Conventional gas turbine engine stator vane assemblies lack a visible indicator for correct alignment between the stator vane and lever arm, leading to potential misalignment and aerodynamic excitation issues during engine operation, which can result in disc post cracking and failure.

Innovation Solution

A variable stator vane assembly with an upper stem featuring an alignment projection that passes through an aperture in the lever arm, providing a visible indication of correct axial orientation, ensuring proper mounting and preventing misalignment, while maintaining a standard mounting process.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If no alignment indicator is provided on the lever arm, then the mounting process remains simple and cost-effective, but correct alignment between the stator vane and lever arm cannot be verified, leading to potential misalignment and aerodynamic excitation issues

Engineering Contradiction:
Improvealignment accuracyVSAvoidmounting indicator complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The lever arm assembly itself provides the alignment indication through its own structural features (aperture and engagement face geometry) without requiring separate external indicators or complex alignment tools. The system uses its inherent components to verify correct installation orientation.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The alignment verification is achieved by adding a dimensional feature (the aperture positioned at a specific location relative to the engagement face) that provides a new degree of alignment checking beyond the basic mechanical connection, allowing visual confirmation of correct orientation.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Loss of information

If an alignment indicator is added to the lever arm, then correct orientation can be visually confirmed, but the device complexity and machining requirements increase

Engineering Contradiction:
Improvealignment informationVSAvoidmanufacturing simplicity
Core Design Contradiction:
Loss of informationVSEase of manufacture

Solution Approach 1:

The alignment information is provided by the lever arm's own structural features (aperture and engagement face) rather than requiring separate external indicators, markings, or complex alignment tools to be added during manufacturing.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The alignment verification is achieved by incorporating a positional dimension (the aperture located at a specific offset from the engagement face) that provides visual confirmation of correct orientation without adding complex manufacturing steps.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

3Adaptability or versatility

If the bolt is removed for instrumentation fitting, then testing capabilities are improved, but the relative alignment between stator vane and lever arm may be lost, causing disc post cracking and failure

Engineering Contradiction:
Improveinstrumentation capabilityVSAvoidalignment retention
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The lever arm assembly provides its own alignment verification capability through the aperture-feature relationship, allowing operators to confirm correct reassembly after bolt removal without requiring specialized alignment tools or procedures.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The visible alignment indication provided by the aperture and engagement face geometry gives immediate feedback to operators during assembly and reassembly operations, confirming whether components are correctly oriented before securing with the bolt.

Inventive Principle:
Principle #23Feedback

Data Source

PatentEP2299064B1Variable stator vane assembly and corresponding compressor for a gas turbine engine
Publication Date: 2014.08.06 ROLLS ROYCE PLC
  • EP2299064B1 patent drawingFigure 1
  • EP2299064B1 patent drawingFigure 2~3
  • EP2299064B1 patent drawingFigure 4

AI summary

A variable stator vane assembly for a gas turbine engine has a projection protruding from the upper stem of the vane and which engages an aperture in the vane lever to provide a visual indication of correct alignment between the lever and the vane.