Thrust Ring Friction Damper for Nested Shaft Torsional Vibration

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Solution Overview

Problem

Torsional vibration between nested shafts in drive train or transmission systems leads to equipment fatigue and undesired fluctuations in rotational speed.

Innovation Solution

A vibration damping assembly is implemented, comprising a rotor shaft, a disconnect shaft nested within it, and a journal shaft selectively coupled to the disconnect shaft. A thrust journal bearing and thrust washer are used, with a biasing mechanism to engage the thrust washer with the bearing, creating a friction interface to dampen vibrations.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Power

If nested shafts are used to transmit kinetic energy, then power transmission efficiency is improved, but torsional vibration occurs causing equipment fatigue and rotational speed fluctuations

Engineering Contradiction:

Improvepower transmission efficiencyVSAvoidequipment fatigue resistance

Core Design Contradiction:

PowerVSReliability

Solution Approach 1:

The patent converts the harmful torsional vibrations into beneficial frictional engagement. The vibration damping mechanism uses the relative oscillatory motion between shafts to press the thrust washer against the thrust bearing, generating friction that dissipates vibrational energy. The biasing mechanism ensures that during torsional oscillations, the friction interface is activated to dampen vibrations, transforming the harmful effect into a protective function.

Inventive Principle:

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

Solution Approach 2:

The patent introduces a vibration damping mechanism as an intermediary element between the nested shafts. This mechanism includes a thrust washer and thrust bearing that mediate the interaction between shafts, providing frictional damping without completely coupling or decoupling the shafts. The intermediary mechanism allows power transmission while actively dampening torsional vibrations.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Reliability

If a vibration damping mechanism with friction engagement is introduced, then torsional vibrations are reduced, but device complexity increases

Engineering Contradiction:

Improvevibration damping effectivenessVSAvoidnumber of components

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent designs the vibration damping mechanism to serve multiple functions within a compact structure. The thrust washer and thrust bearing not only dampen vibrations but also support axial loads between the shafts. The biasing mechanism provides both the necessary frictional engagement for damping and maintains proper clearance and alignment. This multi-functionality reduces the need for separate vibration damping components.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Solution Approach 2:

The vibration damping mechanism is nested within the existing shaft structure. The thrust washer is mounted on the inner shaft and engages with the thrust bearing on the outer shaft, creating a compact arrangement that utilizes the existing radial space between nested shafts. This nesting approach minimizes additional space requirements and reduces overall device complexity.

Inventive Principle:

Principle #7Nested doll (Nesting)

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 vibration damping assembly effectively reduces torsional vibrations, preventing equipment fatigue and stabilizing rotational speed by generating sufficient friction to prevent continuous oscillation between the journal shaft and the rotor shaft.

Implementation Method 1

A friction interface is created between the thrust washer and the thrust journal bearing. The biasing mechanism applies a biasing force to the disconnect shaft, causing the thrust washer to engage with the thrust journal bearing.

Methodology Applied

Scientific EffectFriction: Friction

Implementation Method 2

Methodology Applied

Scientific EffectVibration damping: Damping

Data Source

PatentEP4495380A1Thrust ring frictional damper

Publication Date: 2025.01.22 HAMILTON SUNDSTRAND CORP

Figure 1
Figure 2

AI summary

A system includes a rotor shaft (24) rotatable about an axis, a disconnect shaft (26) nested at least partially within an interior of the rotor shaft (24), and a journal shaft (34) selectively rotatably coupled to the disconnect shaft (26). A vibration damping mechanism is arranged between the rotor shaft (24) and the journal shaft (34). The vibration damping mechanism includes a thrust journal bearing affixed to the rotor shaft (24) and a thrust washer mounted to the journal shaft (34). A biasing mechanism (80) is operably coupled to disconnect shaft (26) to bias the thrust washer into frictional engagement with the thrust journal bearing.