Variable Squeeze Damper Assembly for Gas Turbine Vibration Control

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Solution Overview

Problem

Gas turbine engines face challenges in effectively damping rotatable components to mitigate vibration and misalignment during operation, as existing solutions do not provide sufficient control over damping rates and modes.

Innovation Solution

A variable squeeze damper assembly with two fluid passages and valves that can be controlled to achieve different damping modes, including high, low, and medium damping, by delivering lubricant to annular cavities to absorb energy from rotating components, allowing for adjustable damping rates based on operational conditions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a fixed damping rate is used to dampen the rotatable shaft, then vibration is reduced, but the system cannot adapt to different operational conditions and may cause parasitic losses

Engineering Contradiction:
Improvevibration reductionVSAvoidadaptability to different operational conditions
Core Design Contradiction:
ReliabilityVSAdaptability or versatility

Solution Approach 1:

The damper assembly incorporates variable damping rates achieved through multiple fluid passages (first and second fluid passages) that can be selectively activated. The system transitions from a fixed damping mechanism to a dynamic one where the damping rate can be adjusted based on operational conditions, allowing the rotatable shaft to be dampened at different rates (first rate, second rate, third rate) as needed.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The invention changes the damping parameter from a fixed value to a variable one by controlling fluid flow through different passages. By altering the fluid flow parameters (which fluid passage is active, flow rate), the damping characteristic is dynamically adjusted to match different operational requirements, resolving the contradiction between reliable vibration reduction and adaptability.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If high damping is applied continuously to the rotatable shaft, then vibration and misalignment are reduced, but parasitic losses increase and lubricant may stagnate

Engineering Contradiction:
Improvevibration and misalignment controlVSAvoidparasitic losses
Core Design Contradiction:
ReliabilityVSLoss of energy

Solution Approach 1:

The system employs periodic or selective damping action rather than continuous high damping. The controller activates specific fluid passages (first, second, or third passage) based on detected operational conditions, applying damping only when and where needed. This periodic/selective action reduces parasitic losses while maintaining effective vibration and misalignment control.

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The damper assembly applies damping locally and selectively to the rotatable shaft based on specific operational conditions rather than uniformly throughout operation. Different fluid passages target different damping needs, allowing high damping to be applied only when vibration or misalignment issues are detected, thereby reducing overall parasitic losses.

Inventive Principle:
Principle #3Local quality

3Adaptability or versatility

If multiple fluid passages are used to provide variable damping rates, then adaptability to different operational conditions is improved, but device complexity increases

Engineering Contradiction:
Improvevariable damping ratesVSAvoidnumber of fluid passages and valves
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The damper assembly integrates multiple fluid passages (first, second, and third passages) into a single multi-functional device that can provide multiple damping rates. This universal design allows one damper assembly to handle various operational conditions that would otherwise require separate damping systems, managing complexity through functional integration rather than proliferation of separate components.

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

Solution Approach 2:

The system incorporates sensors that automatically detect operational conditions and trigger appropriate damping responses without requiring external intervention. The controller autonomously manages which fluid passages are activated based on real-time conditions, reducing the operational complexity despite the presence of multiple passages. The system essentially manages itself, selecting the appropriate damping mode.

Inventive Principle:
Principle #25Self-service

4Reliability

If damping is applied during all operational phases, then vibration is consistently controlled, but the risk of high temperatures and lubricant stagnation increases

Engineering Contradiction:
Improveconsistent vibration controlVSAvoidrisk of high temperatures
Core Design Contradiction:
ReliabilityVSTemperature

Solution Approach 1:

The damper system applies damping periodically or selectively based on detected operational conditions rather than continuously during all phases. The controller monitors the operational phase and activates damping only when vibration control is actually needed, allowing periods where damping is reduced or suspended. This prevents lubricant stagnation and heat buildup that would occur with continuous damping application.

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The damping application is made dynamic rather than static, transitioning from continuous damping to condition-based damping. The system adapts its damping application to the actual operational phase, reducing or suspending damping during phases where it is not needed, thereby preventing temperature issues and lubricant stagnation while maintaining vibration control when required.

Inventive Principle:
Principle #15Dynamics

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 damper assembly effectively reduces vibration and misalignment by providing variable damping rates, optimizing load, displacement, and rotor strain energy, while minimizing parasitic losses and reducing the risk of high temperatures and lubricant stagnation.

Implementation Method 1

flow of fluid through the first fluid passage causes the rotatable shaft to be dampened at a first rate, and flow of fluid through the second fluid passage causes the rotatable shaft to be dampened at a second, different rate

Methodology Applied
Scientific EffectViscous damping: Viscous Damping

Data Source

PatentEP3477133B1Damper assembly for gas turbine engines
Publication Date: 2021.03.24 RTX CORP
  • EP3477133B1 patent drawingFigure 1
  • EP3477133B1 patent drawingFigure 2A
  • EP3477133B1 patent drawingFigure 2B~2C

AI summary

A damper assembly (60) includes a first housing (62) adjacent to a second housing (64) that supports a rotatable gas turbine engine component (66). The first housing (62) defines first and second fluid passages (76,78). The first fluid passage (76) is coupled to a first valve (80). One of the first and second housings (62,64) defines first, second and third annular grooves (84A,84B,84C) that receive respective first, second and third seal members (86A,86B,86C). The first and second housings (62,64) define a first annular damper cavity (88A) between the first and second seal members (86A,86B) and in fluid communication with the first fluid passage (76), and define a second annular damper cavity (88B) between the second and third seal members (86B,86C) and in fluid communication with the second fluid passage (78).