Cone Angle Insert for Wind Turbine Rotor Blade Stress Reduction

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Solution Overview

Problem

Existing wind turbine rotor blade coning methods either reduce energy capture or cause stress and ovalization concerns, failing to adequately address the need for increased separation from the tower and proper pitch performance.

Innovation Solution

An annular or cylindrical insert is used between the hub and bearing assembly, orienting rotor blades at a cone angle while reducing stress and ovalization risks, and facilitating proper bearing assembly performance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If rotor blade size is increased to capture more energy, then energy capture increases, but rotor blade deflection increases causing risk of striking the tower

Engineering Contradiction:
Improveenergy captureVSAvoidrisk of rotor blade striking tower
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The patent introduces a cone angle configuration that angles the rotor blades away from the tower in a radial dimension, creating spatial separation between the rotating blade path and the stationary tower structure. This dimensional approach allows larger blades to operate without collision risk.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Reliability

If rotor blade curvature is modified to curve blades away from the tower, then striking risk is reduced, but energy capture is reduced

Engineering Contradiction:
Improverisk of rotor blade striking towerVSAvoidenergy capture
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The patent segments the rotor blade system into modular components: the hub, the rotor blades, and a separate coning mechanism. This allows the blades to maintain their optimal aerodynamic shape for energy capture while the hub assembly provides the coning function to prevent tower strikes.

Inventive Principle:
Principle #1Segmentation

3Reliability

If hub flange or rotor blade root is angled at cone angle, then coning is achieved, but stress and ovalization concerns increase

Engineering Contradiction:
Improveconing functionVSAvoidstress and ovalization
Core Design Contradiction:
ReliabilityVSStrength

Solution Approach 1:

The patent introduces an intermediary coning mechanism between the hub and rotor blades that provides the necessary angular orientation without directly stressing the blade roots or hub flange. This intermediate structure absorbs the coning function while preserving the structural integrity of critical components.

Inventive Principle:
Principle #24Intermediary (Mediator)

4Reliability

If spacers are used between hub and rotor blade to provide cone angle, then coning is achieved, but stress and ovalization concerns increase

Engineering Contradiction:
Improveconing functionVSAvoidstress and ovalization
Core Design Contradiction:
ReliabilityVSStrength

Solution Approach 1:

The patent employs a coning mechanism that replicates the functional effect of traditional spacers and hub flange angling without replicating their structural stress problems. The new design achieves the same coning function through a different structural approach that eliminates ovalization concerns.

Inventive Principle:
Principle #26Copying

5Reliability

If conventional coning methods are used, then rotor blade separation from tower is increased, but pitch performance is not adequately addressed

Engineering Contradiction:
Improveseparation from towerVSAvoidpitch performance
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The patent designs a coning mechanism that performs multiple functions simultaneously: it provides the necessary cone angle for tower separation, maintains proper structural alignment, and preserves full pitch performance capability. This multi-functional design eliminates the need to compromise between coning and pitch operations.

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

Data Source

PatentEP2679805B1Cone angle insert for wind turbine rotor
Publication Date: 2015.02.18 GENERAL ELECTRIC CO
  • EP2679805B1 patent drawingFigure 1
  • EP2679805B1 patent drawingFigure 2
  • EP2679805B1 patent drawingFigure 3

AI summary

A rotor for a wind turbine is disclosed. The rotor includes a hub, a rotor blade, and a bearing assembly configured to rotate the rotor blade with respect to the hub. The rotor further includes an insert, the insert including a first end, a second end, and a body extending therebetween. The first end is coupled to the bearing assembly and the second end is coupled to the rotor blade. The second end defines a second plane oriented at a cone angle with respect to a first plane defined by the first end.