Rotor Assembly Rolling Damper for Blade Vibration Harmonics

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Solution Overview

Problem

Existing rotor assemblies face challenges in reducing vibration of rotor blades at natural frequencies corresponding to rotational speeds, limiting their flexibility and reliability.

Innovation Solution

Incorporating rolling elements that roll on curved surfaces within the rotor disc, with their frequency proportional to the rotational speed, and adjusting the curvature and position of these elements to dampen vibrations at specific harmonics, combined with U-shaped plate springs to enhance frictional damping.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If an adjustment member is interposed between the platform and damper member to adjust the contact angle, then the flexibility and reliability of the rotor assembly design is improved, but the vibration of the rotor blade at the natural frequency corresponding to the rotational speed cannot be effectively reduced

Engineering Contradiction:
Improveflexibility of rotor assembly designVSAvoidvibration reduction effectiveness
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The invention changes the geometric parameters of the damper member by providing a curved surface instead of a flat surface, and introduces rolling elements to change the contact mechanism. This allows the rolling frequency to be proportional to rotational speed, enabling effective vibration reduction at natural frequencies while maintaining design flexibility.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The invention applies curvature by providing a curved surface on the damper member instead of a flat surface. This curved surface works in conjunction with rolling elements to create a contact mechanism where the rolling frequency is proportional to rotational speed, effectively addressing the vibration problem at natural frequencies.

Inventive Principle:
Principle #14Spheroidality (Curvature)

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 rotor blade vibrations at natural frequencies, enhancing the flexibility and reliability of the rotor assembly by synchronizing rolling element frequencies with rotational speed harmonics and utilizing frictional forces for additional damping.

Implementation Method 1

as the rotor assembly rotates, the centrifugal force acts on the rolling element. Due to the action of the centrifugal force, the rolling element is pressed against the curved surface facing inward in the radial direction of the rotor disc

Methodology Applied
Scientific EffectCentrifugal force: Centrifugal Force

Implementation Method 2

when the rotor blade vibrates, the rolling element rolls on the curved surface

Methodology Applied
Scientific EffectRolling: Roller

Implementation Method 3

a curved surface CS facing inward in the radial direction of the rotor disc is provided on a U-shaped plate spring 5, friction between which and the rotor blade 3 damps vibrations occurring in the rotor blade 3

Methodology Applied
Scientific EffectFriction: Friction

Data Source

PatentEP3839210B1Rotor assembly and rotating machine
Publication Date: 2022.09.07 MITSUBICHI HEAVY IND AERO ENGINES LTD
  • EP3839210B1 patent drawingFigure 1A~1B
  • EP3839210B1 patent drawingFigure 2A~2B
  • EP3839210B1 patent drawingFigure 3A~3B

AI summary

A rotor assembly includes: a rotor disc; a plurality of rotor blades fixed to the rotor disc and extending radially outward in a radial direction of the rotor disc; and at least one rolling element configured to roll on a curved surface facing inward in the radial direction of the rotor disc.