Variable Vane Damping Assembly With Elastomeric Bushing

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Solution Overview

Problem

Variable vanes in turbomachines experience vibrations during operation, leading to fatigue and damage, which existing technologies have not adequately addressed.

Innovation Solution

A variable vane damping assembly comprising a trunnion, inner elastomeric bushing, and outer metallic bushing, where the elastomeric bushing is bonded to both the trunnion and outer bushing, forming a vibration-damping unit that rotates with the variable vane to absorb vibratory loads.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If variable vanes are used to influence flow through the turbomachine, then flow control capability is improved, but the variable vanes are exposed to vibrations that can fatigue and damage them

Engineering Contradiction:
Improveflow control capabilityVSAvoidvane durability
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The patent introduces a damping assembly as an intermediary component between the variable vane and its support structure. This assembly includes a trunnion, inner elastomeric bushing, and outer bushing that work together to isolate the variable vane from vibratory loads while maintaining its flow control function. The elastomeric material acts as a mediator that absorbs and dissipates vibration energy, protecting the vane from fatigue damage.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent converts the harmful vibratory loads into beneficial damping action by using elastomeric materials that absorb and dissipate vibration energy. The damping assembly transforms the mechanical vibrations that would otherwise cause fatigue and damage into controlled elastic deformation and heat dissipation, thereby protecting the variable vane while maintaining operational flexibility.

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

2Reliability

If a damping assembly with elastomeric bushing is added to reduce vibrations, then reliability is improved, but device complexity increases

Engineering Contradiction:
Improvevane durabilityVSAvoidassembly structure
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The damping assembly employs a nested structure where the inner elastomeric bushing is positioned within the outer bushing, and both are mounted on the trunnion. This nested arrangement consolidates multiple damping and support functions into a compact integrated unit that rotates with the variable vane, minimizing space requirements and simplifying installation while maintaining reliability.

Inventive Principle:
Principle #7Nested doll (Nesting)

Solution Approach 2:

The damping assembly utilizes composite construction by combining elastomeric material with metallic components (trunnion and outer bushing). This composite approach leverages the vibration-absorbing properties of elastomers and the structural strength of metals, achieving effective damping with a relatively simple and robust assembly that does not significantly increase overall device complexity.

Inventive Principle:
Principle #40Composite materials

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 damping assembly effectively reduces vibratory responses in variable vanes, thereby protecting them from damage and providing designers with more design options by mitigating vibratory loads.

Implementation Method 1

inner elastomeric bushing (70)

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 2

The damping assembly effectively reduces vibratory responses in variable vanes, thereby protecting them from damage

Methodology Applied
Scientific EffectVibration damping: Damping

Data Source

PatentEP2620602B1Variable vane damping assembly, corresponding variable vane assembly and method of damping a variable vane
Publication Date: 2021.10.20 UNITED TECH CORP
  • EP2620602B1 patent drawingFigure 1
  • EP2620602B1 patent drawingFigure 2~5
  • EP2620602B1 patent drawingFigure 3~4

AI summary

A variable vane damping assembly (62) includes an inner bushing (70) and an outer bushing (66). The inner bushing (70) comprises an elastomeric material. A corresponding variable vane assembly and method of damping a variable vane are also provided.