Wind Turbine Spar Cap Clipping Layer for Precise Mold Placement

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Solution Overview

Problem

The integration of spar caps in wind turbine rotor blades, particularly near the trailing edge, is challenging due to limited space and the need for precise placement to ensure structural integrity, load distribution, and aerodynamic performance.

Innovation Solution

A spar cap design featuring a stack of fiber material layers with a clipping layer protruding laterally to facilitate precise placement in a mold, using a mold with adjustable protrusions and clamping devices to maintain position during resin infusion.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If a spar cap is integrated near the trailing edge to provide stiffness, then the structural integrity and load-bearing capacity are improved, but the manufacturing precision and placement accuracy deteriorate due to limited space and complex geometry

Engineering Contradiction:
ImprovestiffnessVSAvoidplacement accuracy
Core Design Contradiction:
StrengthVSManufacturing precision

Solution Approach 1:

The spar cap is divided into multiple separate fiber layers that can be individually placed and positioned. This segmentation allows for precise control of each layer's placement in the limited space near the trailing edge, ensuring accurate positioning while maintaining the required stiffness through the stacked configuration

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The fiber layers are pre-assembled into a spar cap structure before integration into the blade. This preliminary assembly allows for quality control and precise positioning to be established before the final integration step, improving placement accuracy in the constrained trailing edge region

Inventive Principle:
Principle #10Preliminary action

2Strength

If the spar cap thickness is increased to provide sufficient stiffness, then the structural strength is improved, but the available space in the trailing edge region is exceeded

Engineering Contradiction:
ImprovestiffnessVSAvoidspar cap thickness
Core Design Contradiction:
StrengthVSVolume of moving object

Solution Approach 1:

Instead of increasing thickness in the vertical direction, the solution uses multiple thin fiber layers stacked in a configuration that optimizes stiffness through dimensional arrangement. The fiber layers are oriented and positioned in specific dimensions to achieve required stiffness without excessive thickness that would exceed trailing edge space constraints

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

Solution Approach 2:

The spar cap utilizes fiber-reinforced composite material with optimized fiber orientation and stacking sequence. This allows maximum stiffness to be achieved with minimal thickness by leveraging the high strength-to-weight ratio and anisotropic properties of composite materials, fitting within the limited trailing edge space

Inventive Principle:
Principle #40Composite materials

3Manufacturing precision

If the spar cap is placed with high precision to ensure load distribution, then the structural performance is improved, but the manufacturing complexity increases

Engineering Contradiction:
Improveplacement accuracyVSAvoidmanufacturing complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The spar cap structure is designed to self-align and self-position during the manufacturing process. The fiber layers and spar cap configuration inherently guide themselves into the correct position through geometric features and stacking arrangement, reducing the need for complex external positioning mechanisms and simplifying manufacturing while maintaining high placement accuracy

Inventive Principle:
Principle #25Self-service

Data Source

PatentEP4706945A1Spar cap for a wind turbine rotor blade, set for manufacturing a half shell of a wind turbine rotor blade, assembly comprising a spar cap and a mold, and method of manufacturing a half shell of a wind turbine rotor blade
Publication Date: 2026.03.11 NORDEX ENERGY SE & CO KG
  • EP4706945A1 patent drawingFigure 1
  • EP4706945A1 patent drawingFigure 2~3
  • EP4706945A1 patent drawingFigure 4~6

AI summary

The present invention concerns a apar cap (140) for a wind turbine rotor blade (110), comprising a stack (141) of fiber material layers, which are stacked in a stacking direction (147) from a bottom face (143) to a top face (144), and a clipping layer (145) which is arranged on the top face (144) of the stack (141), wherein the clipping layer (145) protrudes beyond the stack (141) of fiber material layers in a lateral direction (148) which is perpendicular to the stacking direction (147). Further aspects concern a set for manufacturing a half shell of a wind turbine rotor blade, an assembly comprising a spar cap and a mold, and a method of manufacturing a half shell of a wind turbine rotor blade.