Rotor Blade Shell Alignment Using Interference-Fit Tensioning Blocks

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Solution Overview

Problem

Handling and maintaining the precise shape and position of large wind turbine rotor blades is challenging due to their complex structure, which can lead to damage during production, transport, and alignment issues, such as 'overbite' and 'ovalization', necessitating a method to manipulate their shape and position without causing structural harm.

Innovation Solution

A method involving tensioning blocks mounted to wind turbine rotor blade shell members using threaded bolts and inserts, creating an interference fit to apply lateral forces, allowing manipulation without damaging the structure, and using multiple tensioning blocks and elements to align or maintain shape.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If substantial forces are applied to maintain or bring a wind turbine rotor blade shell member into a desired position and shape, then the shape and position can be controlled, but the risk of damaging the shell member structure increases

Engineering Contradiction:
Improveshape and position controlVSAvoidstructural damage risk
Core Design Contradiction:
Manufacturing precisionVSObject-affected harmful factors

Solution Approach 1:

The rotor blade shell member is divided into multiple segments or sections, each equipped with its own tensioning blocks and manipulation points. This allows localized adjustment of specific sections without applying excessive forces to the entire structure, thereby maintaining shape precision while reducing overall structural stress.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Tensioning blocks are introduced as intermediary elements between the manipulation forces and the shell member structure. These blocks distribute and transmit forces through controlled interference fits with inserts, acting as mediators that enable precise position control while protecting the shell member from direct substantial forces that could cause damage.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Productivity

If the rotor blade shell members are assembled with non-perfect alignment (overbite), then production can proceed, but repair becomes necessary and complex

Engineering Contradiction:
Improveproduction continuityVSAvoidalignment repair difficulty
Core Design Contradiction:
ProductivityVSEase of repair

Solution Approach 1:

Tensioning blocks and manipulation features are pre-installed on the shell members during initial assembly. This preliminary preparation enables future alignment adjustments without requiring complex repair procedures, as the necessary components are already in place to facilitate straightforward manipulation and realignment.

Inventive Principle:
Principle #10Preliminary action

3Duration of action of moving object

If large wind turbine rotor blades undergo extended storage, then they can be transported and deployed, but shape deviation (ovalization) occurs

Engineering Contradiction:
Improvestorage durationVSAvoidcircular shape maintenance
Core Design Contradiction:
Duration of action of moving objectVSShape

Solution Approach 1:

Counter-forces are applied through the tensioning blocks and manipulation systems to counteract the gravitational and environmental forces that cause ovalization during extended storage. By actively maintaining the desired circular shape through these preliminary anti-actions, the blade preserves its geometric integrity throughout storage and transport periods.

Inventive Principle:
Principle #9Preliminary anti-action

4Manufacturing precision

If complex procedures and parts are used to manipulate rotor blade shape and position, then precise control can be achieved, but implementation complexity increases

Engineering Contradiction:
Improveshape and position manipulation precisionVSAvoidmanipulation system complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The tensioning blocks and manipulation features are designed to be self-contained units that can be independently adjusted and operated. Each block with its interference-fit insert creates a self-sufficient manipulation point, eliminating the need for complex interconnected systems and reducing overall implementation complexity while maintaining precise control capability.

Inventive Principle:
Principle #25Self-service

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

Enables precise manipulation of rotor blade shape and position without structural damage, facilitating alignment and preventing deformations like 'overbite' and 'ovalization', while being easy to implement and requiring no complex parts or procedures.

Implementation Method 1

the pretensioning force is selected such that between the connection surface of the first insert and the contact surface of the first tensioning block, an interference fit is obtained strong enough to transfer the lateral manipulating force to the first wind turbine rotor blade shell member

Methodology Applied
Scientific EffectInterference fit: Friction

Data Source

PatentEP4477869B1A method for manipulating a shape and/or a position of a wind turbine rotor blade shell member
Publication Date: 2026.01.28 NORDEX ENERGY SE & CO KG
  • EP4477869B1 patent drawingFigure 1
  • EP4477869B1 patent drawingFigure 2a~3b
  • EP4477869B1 patent drawingFigure 4~6

AI summary

A method for manipulating shape and/or position of a wind turbine rotor blade shell member, wherein the wind turbine rotor blade shell member has a connection section and an insert having a connection surface, the insert being adapted to be screw-connected to another element of a wind turbine rotor, comprising the following steps: • providing a tensioning block having a contact surface, • mounting the tensioning block to the wind turbine rotor blade shell member with a threaded bolt which is screwed into the insert and pretensioned such that the contact surface of the tensioning block is pressed against the connection surface of the insert with a pretensioning force, • applying a lateral manipulating force to the tensioning block, • wherein the pretensioning force is selected such that between the connection surface of the insert and the contact surface of the tensioning block, an interference fit is obtained strong enough to transfer the lateral manipulating force to the wind turbine rotor blade shell member.