Flyweight Damper Assembly for Nested Shaft Torsional Vibration

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Solution Overview

Problem

Torsional vibration between nested shafts leads to noise generation, equipment fatigue, and undesired rotational speed fluctuations in drive trains and similar systems.

Innovation Solution

A vibration damping assembly using a collar and a cage with flyweights and support wedges that create a wedging force to pin flyweights in position, generating a frictional force to dampen torsional vibrations through centrifugal loads.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Power

If nested shafts are used to transmit kinetic energy, then power transmission capability is improved, but torsional vibration occurs causing noise and equipment fatigue

Engineering Contradiction:
Improvekinetic energy transmissionVSAvoidtorsional vibration
Core Design Contradiction:
PowerVSObject-generated harmful factors

Solution Approach 1:

The patent converts the harmful torsional vibrations into beneficial frictional damping forces. The flyweights experience centrifugal forces during torsional oscillations, pressing them against the shaft surface to generate friction that dissipates vibrational energy as heat, thereby converting the harmful vibration into a useful damping mechanism

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

Solution Approach 2:

The patent employs dynamic elements (flyweights) that change their state based on operational conditions. During normal rotation, flyweights remain stationary relative to the shaft. During torsional vibrations, centrifugal forces cause flyweights to move radially outward and press against the shaft, dynamically activating the damping mechanism only when needed

Inventive Principle:
Principle #15Dynamics

2Object-generated harmful factors

If a vibration damping assembly with flyweights is added, then torsional vibration is reduced, but device complexity increases

Engineering Contradiction:
Improvetorsional vibrationVSAvoidassembly structure
Core Design Contradiction:
Object-generated harmful factorsVSDevice complexity

Solution Approach 1:

The patent places the damping assembly (cage with flyweights) inside the hollow interior of the shaft, nesting one component within another. This eliminates the need for separate external damping devices and reduces overall system complexity while maintaining effective vibration damping

Inventive Principle:
Principle #7Nested doll (Nesting)

Solution Approach 2:

The shaft's hollow interior serves dual purposes: structural function as a shaft and housing for the damping mechanism. The cage structure provides both structural support and mounting for the flyweights, achieving multiple functions with a single integrated design

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

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

Effectively reduces torsional vibrations by creating a frictional force that counteracts oscillations, thereby reducing noise and equipment fatigue.

Implementation Method 1

the at least one flyweight rotates with the at least one nested shaft about a central axis. The at least one flyweight is configured to engage an adjacent surface of the at least one nested shaft

Methodology Applied
Scientific EffectCentrifugal force: Centrifugal Force

Implementation Method 2

generating a frictional force to dampen torsional vibrations

Methodology Applied
Scientific EffectFriction: Friction

Data Source

PatentEP4098905B1Flyweight damper
Publication Date: 2025.10.22 HAMILTON SUNDSTRAND CORP
  • EP4098905B1 patent drawingFigure 1
  • EP4098905B1 patent drawingFigure 2
  • EP4098905B1 patent drawingFigure 3

AI summary

A vibration damping assembly (32) for use with a second shaft (26) nested within an interior of a first shaft (24) is provided including a collar (34) rotatable with the first shaft, and a cage (46) rotatable with the second shaft and having at least one window formed therein. The collar and the cage are mounted concentrically. At least one damping mechanism (60) is positioned within the at least one window. The at least one damping mechanism includes at least one flyweight and at least one support wedge. The at least one flyweight movable relative to the cage to frictionally engage an adjacent surface of the collar.