Fluid-Damped Geartrain Brake for Turbine Engine Vibration Control

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Solution Overview

Problem

Existing aircraft propulsion system geartrains and support systems face challenges in effectively managing vibrations and rotational control, particularly during mode transitions, which can lead to bearing damage and inefficiencies in power transfer.

Innovation Solution

Incorporation of a fluid damper and lubricant circuit to dampen vibrations in the geartrain components, combined with a brake and lock device to control rotation, allowing for efficient power transfer and reduced wear, using a lubricant plenum and compliant coupling for flexibility.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If a brake or lock device is used to control rotation of geartrain components, then rotational control is improved, but vibrations in the device are increased

Engineering Contradiction:
Improverotational controlVSAvoidvibrations
Core Design Contradiction:
Ease of operationVSObject-affected harmful factors

Solution Approach 1:

A fluid damper is introduced as an intermediary element between the brake/lock device structure and the stationary structure. The damper contains a fluid that provides damping forces to reduce vibrations in the brake or lock device while allowing it to perform its rotational control function, thus resolving the contradiction between operational control and vibration reduction.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The invention employs a fluid-based damping mechanism where lubricant or hydraulic fluid is used to dampen vibrations in the brake or lock device. The fluid circulates within the damper structure, utilizing hydraulic principles to absorb and dissipate vibrational energy, thereby reducing harmful vibrations while maintaining rotational control capability.

Inventive Principle:
Principle #29Pneumatics and hydraulics

2Object-affected harmful factors

If a fluid damper is added to reduce vibrations, then vibration damping is improved, but device complexity is increased

Engineering Contradiction:
ImprovevibrationsVSAvoidstructure
Core Design Contradiction:
Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The fluid damper is integrated with the existing brake or lock device structure rather than being a completely separate system. The damper shares structural elements and mounting points with the brake/lock device, combining vibration damping functionality with the existing rotational control mechanism, thus reducing overall system complexity despite adding damping capability.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The fluid damper is designed to serve multiple functions: it dampens vibrations in the brake or lock device, provides structural support, and may also contribute to the lubrication system. This multi-functionality reduces the need for separate dedicated components, thereby minimizing the increase in overall device complexity while achieving effective vibration damping.

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

3Reliability

If a lubricant circuit is implemented to maintain lubrication, then bearing protection is improved, but device complexity is increased

Engineering Contradiction:
Improvebearing protectionVSAvoidsystem
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The lubricant circuit is merged with the existing fluid damper system and brake/lock device structure. The same fluid that provides damping in the damper also serves as lubricant for the bearing, combining lubrication delivery with the damping function. This integration reduces the need for separate lubrication system components, thereby improving bearing protection while minimizing the increase in overall system complexity.

Inventive Principle:
Principle #5Merging (Combining)

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 solution effectively reduces vibrations and maintains lubrication, preventing bearing damage and enhancing power transfer efficiency across different operational modes, thereby improving the reliability and performance of the geartrain.

Implementation Method 1

The fluid damper is configured to damp vibrations in the brake

Methodology Applied
Scientific EffectViscous damping: Viscous Damping

Implementation Method 2

The lubricant circuit is configured to deliver lubricant to the lubricant plenum

Methodology Applied
Scientific EffectLubrication: Lubrication

Data Source

PatentEP4530497A1Fluid damper for turbine engine geartrain assembly
Publication Date: 2025.04.02 RTX CORP
  • EP4530497A1 patent drawingFigure 1
  • EP4530497A1 patent drawingFigure 2
  • EP4530497A1 patent drawingFigure 3~4

AI summary

An engine assembly includes a geartrain (72), a device (116, 118) and a fluid damper (146). The geartrain (72) is configured as or otherwise includes an epicyclic gear system (94). A first component (100; 104) of the geartrain (72) is rotatable about an axis (28; 40; 106). The device is configured to brake and/or lock rotation of the first component of the geartrain (72) about the axis (28; 40; 106), and includes a device structure (150). The fluid damper (146) engages the device structure (150) and is configured to damp vibrations in the device.