Variable Guide Vane Actuating System Wear Reduction

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Solution Overview

Problem

Conventional variable guide vane actuating systems in gas turbine engines experience increased wear and inaccuracy due to reduced contact between rotary actuators and actuating links, particularly in radial vane configurations, which limits the vane angle range.

Innovation Solution

The design incorporates a unison ring with radially projecting drive pins and actuating arms featuring profiled surfaces, including curved and flared slots, to maintain contact area and accommodate angular motion, minimizing wear and enhancing accuracy across the full vane angle range.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If the contact between rotary actuator and actuating links is reduced to accommodate greater VGV angle range, then the vane angle range is improved, but wear at the link-actuator interface increases leading to system inaccuracy

Engineering Contradiction:
ImproveVGV angle rangeVSAvoidsystem accuracy
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The actuating link incorporates a curved slot instead of a straight slot, allowing the drive pin to follow a curved path that accommodates the full range of VGV angles while maintaining continuous contact between the actuator and link throughout the motion range

Inventive Principle:
Principle #14Spheroidality (Curvature)

Solution Approach 2:

The system transitions from a static contact arrangement to a dynamic one where the contact point between drive pin and curved slot continuously changes position along the curved path, enabling the mechanism to adapt to varying angular positions while maintaining optimal contact

Inventive Principle:
Principle #15Dynamics

2Device complexity

If conventional rotary actuator with reduced contact is used, then device complexity is reduced, but manufacturing precision and system accuracy deteriorate due to increased wear

Engineering Contradiction:
Improveactuator mechanism complexityVSAvoidvane actuation precision
Core Design Contradiction:
Device complexityVSManufacturing precision

Solution Approach 1:

The curved slot geometry is designed with specific radii and profiles that maintain constant contact between the drive pin and slot throughout the full angular range, eliminating wear-related accuracy loss while keeping the mechanical structure relatively simple

Inventive Principle:
Principle #14Spheroidality (Curvature)

Data Source

PatentEP3617461B1Variable vane actuating system
Publication Date: 2021.10.13 PRATT & WHITNEY CANADA CORP
  • EP3617461B1 patent drawingFigure 1
  • EP3617461B1 patent drawingFigure 2
  • EP3617461B1 patent drawingFigure 3

AI summary

A variable guide vane (VGV) apparatus (26) has a variable guide vane (VGV) (28) rotatable about a vane rotation axis (30). An actuating arm (35) is mounted to the VGV (28). The actuating arm (35) has a fork (36') defining a slot for receiving a drive pin (34). The slot has a curved contour configured to act as a vane angle schedule adjustment.