External Stoppers for Wind Turbine Blade Web Assembly

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Solution Overview

Problem

The existing manual process for assembling and disassembling main web assemblies in wind turbine blades is cumbersome and poses safety and health concerns, especially due to the need to access tight spaces between closely arranged webs.

Innovation Solution

A fastener assembly comprising a shaft with a central portion having stoppers that can be deployed from the outside, allowing the webs to be connected and disconnected without needing to access the space between them, using a first and second fastener on the outside of the assembly.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If manual assembly process is used with washers and tubular spacers, then webs can be connected, but operators must access tight spaces between closely arranged webs causing safety and health concerns

Engineering Contradiction:
Improveassembly accessibilityVSAvoidsafety risks
Core Design Contradiction:
Ease of operationVSObject-affected harmful factors

Solution Approach 1:

The patent extracts the problematic internal components (washers and tubular spacers) from the assembly process by replacing them with external stoppers that protrude from the shaft ends. This allows the fastening function to be achieved without inserting elements into the confined space between webs, eliminating the safety hazards associated with manual access to tight spaces.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The shaft with external stoppers acts as an intermediary tool that performs the fastening function from the outside. Instead of requiring direct manual manipulation of washers and spacers inside the web assembly, the shaft with its protruding stoppers mediates the connection process by engaging with the webs from external access points, thereby resolving the accessibility-safety contradiction.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Ease of repair

If manual disassembly process is used, then fasteners can be removed, but operators need to enter space inside main web assembly which is cumbersome and poses safety concerns

Engineering Contradiction:
Improvedisassembly accessibilityVSAvoidsafety risks
Core Design Contradiction:
Ease of repairVSObject-affected harmful factors

Solution Approach 1:

The design extracts the disassembly operation from the internal space by providing external access points at the shaft ends. The stoppers that protrude externally can be engaged and manipulated from outside the web assembly, allowing complete disassembly without requiring operators to enter the confined internal space, thus eliminating safety hazards during maintenance operations.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The shaft with external stoppers serves as an intermediary mechanism that enables disassembly from external access. Rather than requiring direct manual removal of internal fasteners from inside the web assembly, the external stoppers mediate the disassembly process by providing leverage and engagement points that can be accessed from outside, resolving the contradiction between ease of repair and safety.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Stability of the object's composition

If washers and tubular spacers are used inside web assembly, then webs can be retained, but not all spacers and washers can be removed from inside the assembly

Engineering Contradiction:
Improveweb retentionVSAvoiddisassembly completeness
Core Design Contradiction:
Stability of the object's compositionVSEase of manufacture

Solution Approach 1:

The patent extracts the retention function from internal washers and spacers to external stoppers on the shaft. This allows complete removal of all fastening elements during disassembly, as the stoppers are accessible from external locations. The retention stability is maintained through the external stoppers engaging with the webs, while eliminating the impossibility of complete disassembly associated with internal components.

Inventive Principle:
Principle #2Taking out (Extraction)

4Strength

If staybolts with internal fasteners are used, then webs can be connected, but the process is cumbersome and time-consuming

Engineering Contradiction:
Improveweb connectionVSAvoidassembly efficiency
Core Design Contradiction:
StrengthVSProductivity

Solution Approach 1:

The patent extracts the fastening function from complex internal assemblies of washers and tubular spacers to a simplified external shaft with protruding stoppers. This extraction reduces the number of components and assembly steps required, thereby improving productivity and assembly efficiency while maintaining the structural strength of the web connection through the external stopper engagement.

Inventive Principle:
Principle #2Taking out (Extraction)

Data Source

PatentEP4227521B9Spar web assemblies and suitable fastener assemblies and methods
Publication Date: 2025.04.09 LM WIND POWER AS
  • EP4227521B9 patent drawingFigure 1
  • EP4227521B9 patent drawingFigure 2A~2B
  • EP4227521B9 patent drawingFigure 2C~3B

AI summary

Fastener assemblies for connecting a first web to a second web are disclosed, particularly a main leading edge and trailing edge shear webs of a main shear web assembly. The fasteners are configured to be mounted from the outside of the assembly. The fasteners comprise a shaft, a first fastener, and a second fastener, the shaft having a first end configured to be arranged with the first web, a second end configured to be arranged on the outside of the second web, and a central portion. The central portion includes one or more stoppers near the first end, the stoppers having a deployed position wherein the stoppers protrude beyond the outer surface of the central portion such that the first web can be fixed between the stoppers and the first fastener, and wherein the central portion has a cross-sectional area that is larger than the cross-sectional area of the second end such that the second web can be fixed between the second fastener and the central portion of the shaft.