Wind Turbine Blade Bond Paste Cap for Cavity Migration Control

Solution Overview

Problem

Turbine blades in wind turbines face inefficiency and structural damage due to excess bond paste migrating into the blade cavity, causing weight increase and potential damage during operation.

Innovation Solution

A bond paste cap is placed within the internal cavity of the blade, with trailing leg portions biased against the shell members to prevent excess paste migration and define a dam, ensuring a controlled bond width and reducing weight and structural stress.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If bond paste is applied along the bond line to join shell members, then the shell members are bonded together, but excess bond paste migrates into the interior blade cavity causing weight increase and potential structural damage

Engineering Contradiction:

Improvebond strengthVSAvoidblade weight

Core Design Contradiction:

StrengthVSWeight of moving object

Solution Approach 1:

The bonding process is segmented into controlled zones using the cap structure. The cap divides the bond line into a bonding zone (where paste is applied) and a restricted zone (where migration is prevented), allowing sufficient bond paste for strength while limiting excess paste entry into the cavity

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The cap acts as an intermediary element between the bond line and the interior blade cavity. It mediates the bond paste flow by allowing controlled application for bonding while blocking excessive migration into the cavity, thus protecting the interior structure

Inventive Principle:

Principle #24Intermediary (Mediator)

2Strength

If bond paste is applied along the bond line to join shell members, then the shell members are bonded together, but excess bond paste migrates into the interior blade cavity causing potential structural damage

Engineering Contradiction:

Improvebond strengthVSAvoidstructural reliability

Core Design Contradiction:

StrengthVSReliability

Solution Approach 1:

The bonding process is segmented into controlled zones using the cap structure. The cap divides the bond line into a bonding zone (where paste is applied) and a restricted zone (where migration is prevented), allowing sufficient bond paste for strength while limiting excess paste entry into the cavity

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The cap acts as an intermediary element between the bond line and the interior blade cavity. It mediates the bond paste flow by allowing controlled application for bonding while blocking excessive migration into the cavity, thus protecting the interior structure

Inventive Principle:

Principle #24Intermediary (Mediator)

3Loss of substance

If cap is added to prevent bond paste migration, then excess paste migration is reduced, but device complexity increases

Engineering Contradiction:

Improvebond paste lossVSAvoidbond line complexity

Core Design Contradiction:

Loss of substanceVSDevice complexity

Solution Approach 1:

The cap is constructed as a thin-walled structure that is flexible enough to be inserted and positioned within the blade cavity, yet rigid enough to effectively block bond paste migration. This thin-film approach minimizes added complexity while achieving the prevention function

Inventive Principle:

Principle #30Flexible shells and thin films

Solution Approach 2:

The cap structure is designed to be self-positioning through the biased leg portions that automatically engage with the shell members to define the bond line location, reducing the need for complex positioning mechanisms or additional assembly steps

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

The solution effectively reduces excess bond paste within the blade cavity, enhancing efficiency and preventing damage by maintaining a controlled bond width and minimizing air pockets, thus improving overall wind turbine performance.

Implementation Method 1

The trailing leg portions are in biased engagement against the upper and lower shell members

Methodology Applied

Scientific EffectElasticity: Elasticity

Implementation Method 2

the cap defines a dam at the bond line against migration of excess bond paste further into the internal cavity

Methodology Applied

Scientific EffectPhysical containment: Physical Containment

Data Source

PatentUS9702339B2Wind turbine blades with cap-assisted bond configuration and associated bonding method

Publication Date: 2017.07.11 GE INFRASTRUCTURE TECH LLC

AI summary

A wind turbine blade (16) includes an upper shell member (20) and a lower shell member (22) with an internal cavity (25) therebetween. The shell members are joined with a bond paste (34) at respective bond lines (36, 37) along leading and trailing edges (24, 26) of the blade. A cap (50) is disposed within the internal cavity between the upper and lower shell members along at least one of the leading or trailing edge bond lines. The cap includes a head (52) oriented towards the blade edge and trailing leg portions (56) that span rearward from the head in biased engagement the upper and lower shell members. The cap defines a dam at the bond line against migration of excess bond paste further into the internal cavity. A method is also provided for forming bond lines at the leading or trailing edge with the bond paste caps.