Nested Counter-Rotating Damper for Wind Tower Vibrations

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Solution Overview

Problem

Existing vibration damping devices for wind turbine towers introduce undesirable moments and parasite vibrations, leading to increased complexity and bulkiness, while existing solutions fail to efficiently reduce vibrations without these issues.

Innovation Solution

A device comprising a first inner element and a second outer element, both rotatably mounted around a common axis, with the inner element's center of mass coinciding with the outer element's in a plane orthogonal to the axis, rotating in opposed directions to minimize parasite flexion moments and reduce volume, utilizing a controller to determine rotational speed and phase for effective damping.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-generated harmful factors

If one rotatably mounted element is split into two parts and arranged at both sides of the other element, then parasite vibrations are avoided, but the device becomes much more cumbersome and bulky and the mechanical design more complicated

Engineering Contradiction:
Improveparasite vibrationsVSAvoidmechanical design complexity
Core Design Contradiction:
Object-generated harmful factorsVSDevice complexity

Solution Approach 1:

The inner element is nested within the outer element, both rotating around the same axis. The inner element has a smaller radius and is positioned inside the outer element's circular path, creating a compact nested configuration that eliminates the need for separate side-by-side arrangements while maintaining vibration cancellation capability

Inventive Principle:
Principle #7Nested doll (Nesting)

Solution Approach 2:

The patent combines two rotatable elements (inner and outer) that rotate around the same axis, merging their functions into a single integrated system. This unified approach around a common axis simplifies the mechanical design compared to splitting elements across different locations, while still achieving the goal of eliminating parasite vibrations through coordinated rotation

Inventive Principle:
Principle #5Merging (Combining)

2Object-generated harmful factors

If two elements are arranged at both sides of each other along the rotational axis, then parasite vibrations are avoided, but the volume occupied by the device increases significantly

Engineering Contradiction:
Improveparasite vibrationsVSAvoiddevice volume
Core Design Contradiction:
Object-generated harmful factorsVSVolume of moving object

Solution Approach 1:

The inner element is nested within the outer element's rotational path, with the inner element's radius being smaller than the outer element's radius. This nested arrangement allows both elements to occupy the same radial space rather than requiring separate side-by-side volumes, dramatically reducing the overall device volume while maintaining vibration cancellation functionality

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 device efficiently dampens vibrations by minimizing parasite vibrations and reducing occupied volume, achieving a simpler mechanical design with directed harmonic control forces, thereby enhancing the structural stability and usability of wind turbine towers.

Implementation Method 1

a first element rotatably mounted around a rotational axis and a second element rotatably mounted around said rotational axis... the first element and the second element rotate independently from each other around the rotational axis

Methodology Applied
Scientific EffectCentrifugal force: Centrifugal Force

Implementation Method 2

a first mass which is rotatable in a direction of rotation about a first axis of rotation transverse to the direction of vibration, the first mass having a first controllable moment of inertia about the first axis of rotation

Methodology Applied
Scientific EffectMoment of inertia: Moment of Inertia

Data Source

PatentEP3480490B1Device for damping vibrations in a structure and use of the device
Publication Date: 2021.02.24 SOLETANCHE FREYSSINET SAS
  • EP3480490B1 patent drawingFigure 1
  • EP3480490B1 patent drawingFigure 2~3
  • EP3480490B1 patent drawingFigure 4~5

AI summary

The invention relates to a device for damping vibrations in a structure, comprising a first element (2) rotatably mounted around a rotational axis (3) and a second element (4) rotatably mounted around said rotational axis (3), a radius (R1) of a circle portion (10) delimitating the first element with respect to the rotational axis, being smaller than a radius (r2) of a circle portion (16) delimitating the second element with respect to the rotational axis, the first element being called inner element, and the second element being called outer element.