Rotor Blade Insert with Expandable Sleeve for Force Balance

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Solution Overview

Problem

Existing rotor blade connections for wind turbines face challenges in balancing forces during operation and simplifying production, as they often lead to compression of inserts and limit design options for expansion sleeves.

Innovation Solution

The proposed solution involves arranging an expansion sleeve along the insert's bonded area to the rotor blade body with an internal threaded section, allowing for adjustable force ratios and separate components to optimize the connection, including a cap to prevent contact with the rotor blade body during lamination.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If the expansion sleeve is integrated into the insert (using part of the insert's cross-section), then the connection strength is improved, but the design possibilities for the expansion sleeve are limited

Engineering Contradiction:
Improveconnection strengthVSAvoiddesign possibilities
Core Design Contradiction:
StrengthVSAdaptability or versatility

Solution Approach 1:

The insert is divided into separate functional components: the insert body, the expansion sleeve, and the internal threaded section. This segmentation allows each component to be optimized independently for its specific function while maintaining overall connection strength, thereby resolving the contradiction between strength and design flexibility.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The expansion sleeve acts as an intermediary component between the insert body and the internal threaded section. This mediator approach enables the expansion sleeve to fulfill its function of preventing insert compression without being constrained by the insert's cross-sectional geometry, thus improving design possibilities while maintaining connection strength.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Adaptability or versatility

If the expansion sleeve and internal thread section are separate components, then the design flexibility is improved, but the manufacturing complexity increases

Engineering Contradiction:
Improvedesign flexibilityVSAvoidmanufacturing complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The expansion sleeve and internal threaded section are merged into a single integral component. This combining reduces the number of separate parts from three to two, simplifying the lamination process during rotor blade manufacturing while preserving the design flexibility benefits of having distinct functional zones.

Inventive Principle:
Principle #5Merging (Combining)

3Strength

If the insert length is increased to accommodate the expansion sleeve, then the connection strength is improved, but the manufacturing precision requirements increase

Engineering Contradiction:
Improveconnection strengthVSAvoidinsert length precision
Core Design Contradiction:
StrengthVSManufacturing precision

Solution Approach 1:

By segmenting the insert into separate components (insert body, expansion sleeve, internal threaded section), the overall length requirement is distributed across multiple elements. This allows each segment to be manufactured with standard precision tolerances rather than requiring the entire insert to meet stringent length precision requirements, while still achieving the necessary connection strength.

Inventive Principle:
Principle #1Segmentation

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

This approach enhances the balance of forces in the bolt connection, simplifies production, and allows for optimal adjustment of force ratios, while maintaining structural integrity and preventing insert compression.

Implementation Method 1

an insert (3), which is bonded to the rotor blade body (1)

Methodology Applied
Scientific EffectAdhesive bonding: Adhesive

Data Source

PatentEP4018089B1Rotor blade connection with insert and expandable sleeve
Publication Date: 2024.02.07 WINDNOVATION ENG SOLUTIONS
  • EP4018089B1 patent drawingFigure 1

AI summary

The invention relates to a rotor blade connection for a rotor blade body (1) to a rotor hub or a blade bearing of a wind turbine, having a plurality of inserts (3) which are arranged in the rotor blade body (1) in the blade root region (2) in a mutually spaced manner in the axial direction relative to the rotor blade body (1) and via which a respective connection to a corresponding attachment point on the rotor hub or the rotor blade can be produced under pretension using a pin (7). A respective expandable sleeve (5) is arranged in the connection between the pin (7) and the adhered insert (3), wherein an expandable sleeve (5) adjoins a region (4) of the insert (3), which is adhered to the rotor blade body (1), in the direction of the blade tip and is followed by an inner thread section (6) in order to produce the connection to the pin (7).