Split Ring Damper for Integrally Bladed Rotor Vibration Control

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Solution Overview

Problem

Integrally bladed rotors (IBRs) in turbomachinery face reduced inherent damping, leading to elevated vibratory responses and potential High Cycle Fatigue due to the absence of individual blade attachments and shrouds, necessitating the use of friction dampers to enhance rotor damping.

Innovation Solution

A split ring damper system is integrated into the IBR, featuring a U-shaped design with multiple points of contact and a coefficient of friction between 0.20 to 0.60, which provides enhanced damping by dissipating energy through centrifugal loads and maintaining engagement up to 20 Gs, minimizing rim stiffness impact and capturing both axial and radial deflections.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If an integrally bladed rotor design is used to eliminate individual blade attachments and shrouds, then manufacturing complexity and assembly difficulty are reduced, but inherent rotor damping is reduced leading to elevated vibratory responses

Engineering Contradiction:
Improveblade attachment complexityVSAvoidrotor damping
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The friction damper integrates multiple functional elements into a unified structure: a ring-shaped body combines damping functionality with centrifugal loading capability, while multiple contact points merge several damping actions into a single component. This merging approach resolves the contradiction by adding damping function without proportionally increasing overall system complexity.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The friction damper acts as an intermediary element between the rotor hub and the vibratory forces. It introduces a controlled friction interface that dissipates vibratory energy through sliding friction at multiple contact points, thereby mediating between the rigid IBR structure and the need for energy dissipation.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If a friction damper is added to increase rotor damping, then vibratory responses are reduced, but device complexity and structural modifications increase

Engineering Contradiction:
Improverotor dampingVSAvoiddamper system complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The friction damper is segmented into a ring-shaped body with multiple discrete contact points distributed around the rotor hub perimeter. This segmentation allows the damping function to be distributed across multiple locations, increasing effectiveness while keeping each individual contact point relatively simple in structure.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The ring-shaped friction damper performs multiple functions simultaneously: it provides centrifugal loading through its mass distribution, creates multiple friction contact points for energy dissipation, and maintains a compact structure that minimizes impact on rotor balance. This multi-functionality reduces the need for additional separate components.

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

3Reliability

If the friction damper engages at high Gs to maintain damping effectiveness, then vibratory control is improved, but risk of disengagement or damage under extreme conditions increases

Engineering Contradiction:
Improvedamping effectivenessVSAvoiddamper engagement reliability
Core Design Contradiction:
ReliabilityVSStrength

Solution Approach 1:

The friction damper features localized contact points with specific pressure distribution characteristics. Each contact point is designed to engage locally at optimal positions around the rotor hub, creating concentrated friction forces that are effective at controlling vibration while distributing the overall load across multiple locations.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The friction damper is designed to dynamically adapt its engagement characteristics based on operating conditions. The centrifugal loading creates velocity-dependent friction forces that automatically adjust to maintain contact under varying rotational speeds and vibratory conditions, enhancing both effectiveness and reliability across different operating regimes.

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 split ring damper system effectively increases system damping, maintains rotor balance, and ensures minimal change in airfoil fundamental mode frequencies, reducing vibratory responses and High Cycle Fatigue while maintaining lightweight and optimal stiffness.

Implementation Method 1

AIBR damper system includes a friction damper, such as a split ring damper, mounted to the IBR and configured to dissipate energy through friction between the damper and the IBR

Methodology Applied
Scientific EffectFriction: Friction

Implementation Method 2

maintaining engagement up to 20 Gs

Methodology Applied
Scientific EffectCentrifugal force: Centrifugal Force

Data Source

PatentEP2540980B1Damper for an integrally bladed rotor
Publication Date: 2020.05.13 RTX CORP
  • EP2540980B1 patent drawingFigure 1
  • EP2540980B1 patent drawingFigure 2~3
  • EP2540980B1 patent drawingFigure 4~6B

AI summary

A rotor (60) includes a rotor hub (62) having a rim (64) with a hub face (68, 70), the rim (64) defines a circumferential groove (78). A damper (80) is engaged with the rim (64) at both the hub face (68, 70) and the circumferential groove (78).