Wind Turbine Rotor Blade Split Joint Design

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Solution Overview

Problem

The challenge in wind turbine rotor blades is to achieve a reliable connection while maintaining good aerodynamic behavior, especially with large rotor diameters where split blades are used, and to minimize weight and material usage to reduce costs and durability risks at connection points.

Innovation Solution

A rotor blade design featuring an inner and outer part connected through a thickening in the connection area, which acts as a ridge or wall parallel to air flows, allowing for stable attachment with a double-row threaded rod system that distributes forces effectively and supports aerodynamic efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If numerous connecting bolts are arranged in a circumferential row to join rotor blade sections, then the connection reliability is improved, but the device complexity and material usage increase

Engineering Contradiction:
Improveconnection reliabilityVSAvoiddevice complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The rotor blade is divided into multiple sections (hub-adjacent section and hub-remote section) that can be separately manufactured and then joined together. This segmentation allows for simplified manufacturing of individual sections while achieving reliable connection through the thickening design with integrated connecting elements.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The connecting elements are merged into the thickening structure itself, rather than being separate components. The thickening incorporates recesses and connecting elements that are integrated into the blade sections, reducing the number of separate parts and simplifying the overall connection system.

Inventive Principle:
Principle #5Merging (Combining)

2Power

If rotor blades are made longer to increase rotor diameter, then the power output is improved, but the weight and transport difficulty increase

Engineering Contradiction:
Improvepower outputVSAvoidblade weight
Core Design Contradiction:
PowerVSWeight of moving object

Solution Approach 1:

The rotor blade is divided into multiple sections that can be manufactured separately and joined together. This allows for optimized material distribution and weight reduction in each section while achieving the required overall length for high power output.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The thickening is localized to specific connection areas rather than being distributed along the entire blade length. This allows the blade to maintain lightweight construction in most areas while providing localized reinforcement where structural connection is required.

Inventive Principle:
Principle #3Local quality

3Strength

If the connection area is reinforced to bear entire load of outer blade section, then the strength is improved, but the material usage and weight increase

Engineering Contradiction:
Improveconnection strengthVSAvoidmaterial usage
Core Design Contradiction:
StrengthVSQuantity of substance

Solution Approach 1:

The connecting elements are merged into the thickening structure itself, rather than being separate components. The thickening incorporates recesses and connecting elements that are integrated into the blade sections, reducing the number of separate parts and simplifying the overall connection system.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The thickening is localized to specific connection areas rather than being distributed along the entire blade length. This allows the blade to maintain lightweight construction in most areas while providing localized reinforcement where structural connection is required.

Inventive Principle:
Principle #3Local quality

4Reliability

If a thickening is formed at the joint to create a robust connection area, then the reliability is improved, but the aerodynamic performance may deteriorate

Engineering Contradiction:
Improveconnection reliabilityVSAvoidaerodynamic shape
Core Design Contradiction:
ReliabilityVSShape

Solution Approach 1:

The thickening is localized to specific connection areas rather than being distributed along the entire blade length. This allows the blade to maintain lightweight construction in most areas while providing localized reinforcement where structural connection is required.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The connecting elements are arranged in a double-row configuration, utilizing both radial and circumferential dimensions. This dimensional arrangement allows for effective load distribution while maintaining a compact thickening structure that minimizes aerodynamic interference.

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

Data Source

PatentEP3129644B1Rotor blade for a wind turbine
Publication Date: 2020.11.25 WOBBEN PROPERTIES GMBH
  • EP3129644B1 patent drawingFigure 1
  • EP3129644B1 patent drawingFigure 2
  • EP3129644B1 patent drawingFigure 3~4

AI summary

The invention relates to a rotor blade (1) for a wind turbine (100), comprising a blade root to be fastened to a rotor hub, a blade tip opposite the blade root, a rotor blade longitudinal axis extending from the blade root to the blade tip, an inner rotor blade part (2) on the near side of the blade hub, especially encompassing the blade root, and an outer rotor blade part (4) on the far side of the blade hub, especially encompassing the blade tip. The inner rotor blade part (2) and the outer rotor blade part (4) are joined to one another in a joining zone which forms a bulge (8) in the rotor blade (1).