Detachable Blade Damper Housing for Vibration and Flutter Control

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Solution Overview

Problem

Existing vibration damping devices for rotating machine blades are bulky and difficult to replace, making them unsuitable for downsized applications and prone to deterioration.

Innovation Solution

A vibration damping device with a detachable housing containing an attenuation material, installed under the blade's platform, allowing for space-saving and easy replacement, and optionally incorporating a heavy member for mistuning to suppress flutter.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the vibration damper is encapsulated in the cavity formed in the blade, then the vibration damping effect is achieved, but the blade thickness is increased

Engineering Contradiction:
Improvevibration damping effectVSAvoidblade thickness
Core Design Contradiction:
ReliabilityVSLength of moving object

Solution Approach 1:

The vibration damping function is extracted from the blade structure itself and placed into a separate, removable housing that contains the attenuation material. This allows the damping functionality to be achieved without permanently increasing the blade thickness, as the housing can be installed in a detachable manner.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The vibration damping system is segmented into a separate housing component that can be independently installed and removed from the blade. This segmentation allows the damping function to be added without modifying the fundamental blade structure and thickness.

Inventive Principle:
Principle #1Segmentation

2Reliability

If the vibration damper is encapsulated in the cavity formed in the blade, then the vibration damping effect is achieved, but the replacement difficulty increases

Engineering Contradiction:
Improvevibration damping effectVSAvoidreplacement difficulty
Core Design Contradiction:
ReliabilityVSEase of repair

Solution Approach 1:

The vibration damping system is divided into a separate, modular housing that can be independently removed and replaced. This segmentation enables easy maintenance and replacement of the attenuation material without damaging or modifying the blade structure.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The housing is designed with dynamic, detachable connections to the blade, allowing it to be easily installed and removed as needed. This dynamic design contrasts with permanent encapsulation, enabling flexible maintenance and replacement operations.

Inventive Principle:
Principle #15Dynamics

3Weight of moving object

If the housing includes space independently from the vibration damping space, then the weight is reduced, but the volume increases

Engineering Contradiction:
Improvehousing weightVSAvoidhousing volume
Core Design Contradiction:
Weight of moving objectVSVolume of moving object

Solution Approach 1:

The housing is designed with non-uniform internal structure, creating specific void spaces or chambers that are strategically positioned. This local quality variation allows weight reduction through strategic empty spaces while maintaining the necessary vibration damping volume where attenuation material is placed.

Inventive Principle:
Principle #3Local quality

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 provides a space-saving, easily replaceable vibration damping system that effectively reduces blade vibrations and suppresses flutter, maintaining blade strength without compromising it.

Implementation Method 1

an attenuation material disposed in a vibration damping space formed inside the housing

Methodology Applied
Scientific EffectVibration damping: Damping

Implementation Method 2

an attenuation material disposed in a vibration damping space formed inside the housing

Methodology Applied
Scientific EffectFriction: Friction

Implementation Method 3

it is possible to suppress flutter by adjusting the natural frequency of each blade of the rotating machine by changing the heavy member (so-called mistuning)

Methodology Applied
Scientific EffectMistuning:

Implementation Method 4

a heavy member made of a material higher in density than the attenuation material

Methodology Applied
Scientific EffectInertia: Inertia

Data Source

PatentEP3854996B1Vibration damping device for blade of rotary machine, and rotary machine with same
Publication Date: 2023.08.30 MITSUBICHI HEAVY IND AERO ENGINES LTD
  • EP3854996B1 patent drawingFigure 1
  • EP3854996B1 patent drawingFigure 2
  • EP3854996B1 patent drawingFigure 3

AI summary

A vibration damping device for a blade of a rotary machine according to an embodiment of the present invention is provided with: one or more housings configured so that the housings can be housed in a cavity formed below the platform of the blade and so that the housings are mountable to and removable from the blade; and damping materials provided in vibration damping spaces formed in the housings.