Variable Stator Vane Crankshaft With Adjustable Clevis Positioning

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Solution Overview

Problem

The existing variable stator vane arrangements in gas turbine engines and turbomachines require fixed clevis positions on the crankshaft, which complicates the optimization of operating schedules during development, leading to increased costs and delays, as well as potential compromises in engine performance.

Innovation Solution

A variable stator vane arrangement with movably mounted clevises on the crankshaft, equipped with an adjusting mechanism that allows for adjustable radial and angular positioning of clevises, enabling precise selection and locking of positions using a releasable lock mechanism.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If fixed clevis positions are used on the crankshaft, then the structure is simple and reliable, but the development time and cost increase due to the need for multiple crankshaft variants

Engineering Contradiction:
Improvestructural reliabilityVSAvoiddevelopment time
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The clevis is transformed from a fixed component to a movable one, allowing radial and angular adjustment relative to the crankshaft axis. The adjusting mechanism with releasable lock enables the clevis position to be dynamically changed during development while maintaining stability during operation, thus eliminating the need for multiple fixed crankshaft variants.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The invention allows changing the radial distance and angular position parameters of the clevis on the crankshaft. By providing adjustable positioning mechanisms, the same crankshaft can accommodate different clevis configurations for development purposes, avoiding the time-consuming process of manufacturing multiple crankshaft variants with fixed parameters.

Inventive Principle:
Principle #35Parameter changes

2Manufacturing precision

If multiple crankshafts with different fixed clevis positions are manufactured, then the optimal operating schedule can be found, but the manufacturing cost increases

Engineering Contradiction:
Improveoperating schedule optimizationVSAvoidmanufacturing cost
Core Design Contradiction:
Manufacturing precisionVSEase of manufacture

Solution Approach 1:

A single crankshaft design serves multiple functions by accommodating adjustable clevis positions. The same crankshaft can be used for different development stages and optimization scenarios, replacing the need for multiple specialized crankshaft variants and thereby reducing manufacturing costs.

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

Solution Approach 2:

The adjustable clevis mechanism allows the system to adapt to different operating schedule requirements without requiring separate manufactured components for each configuration, thus achieving manufacturing precision while controlling costs.

Inventive Principle:
Principle #15Dynamics

3Adaptability or versatility

If clevises are made movable and adjustable, then development flexibility improves, but the device complexity increases

Engineering Contradiction:
Improvedevelopment flexibilityVSAvoidcrankshaft structure complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The invention introduces controlled dynamics to the otherwise static crankshaft-clevis system. The adjusting mechanism with releasable lock provides flexibility during development while maintaining structural simplicity and reliability during normal operation, balancing adaptability with complexity.

Inventive Principle:
Principle #15Dynamics

4Device complexity

If fixed clevis positions are used, then the structure remains simple, but engine performance may be compromised due to inability to optimize operating schedules

Engineering Contradiction:
Improvestructural simplicityVSAvoidengine performance
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The adjustable clevis mechanism provides the necessary flexibility to optimize engine performance during development while maintaining relatively simple structural design. The ability to modify clevis positions allows performance tuning without significantly complicating the overall crankshaft structure.

Inventive Principle:
Principle #15Dynamics

Data Source

PatentEP2949878B1A variable stator vane arrangement
Publication Date: 2021.02.17 ROLLS ROYCE DEUT LTD & CO KG
  • EP2949878B1 patent drawingFigure 1
  • EP2949878B1 patent drawingFigure 2
  • EP2949878B1 patent drawingFigure 3

AI summary

A variable stator vane arrangement (35) comprises a casing (36), a plurality of stator vanes (38), at least one control ring (42), a plurality of connecting rods (64,66,68,70) and a crankshaft (44). The stator vanes (38) are circumferentially spaced apart in the casing (36) and the plurality of stator vanes (38) are rotatably mounted in the casing (36). Each control ring (42) is rotatably mounted on the casing (36) and each stator vane (38) is connected to an associated control ring (36). The crankshaft (44) is rotatably mounted on the casing (36). The crankshaft (44) is drivingly connected to each control ring (42) and the crankshaft (44) has an axis and a plurality of clevises (76,78,80,82). Each connecting rod (64,66,68,70) connects one of the clevises (76,78,80,82) on the crankshaft (44) to a respective one of the control rings (42). At least one clevis (76,78,80,82) is adjustably secured to the crankshaft (44) by an adjusting mechanism and the adjusting mechanism is used to select the radial position and/or the angular position of the at least one clevis (76,78,80,82) relative to the axis of the crankshaft (44).