Wind Turbine Blade Root Flange for Accurate Pitch Alignment
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Solution Overview
Problem
Inaccurate pitch alignment of wind turbine blades leads to decreased energy yield and increased loads on the rotor, despite the use of exterior markers for alignment, which are difficult to apply and often result in incorrect mounting.
Innovation Solution
A method involving the manufacturing of wind turbine blades with a ring-shaped root end flange featuring bond line and pitch-angle markers, allowing precise alignment with the pitch bearing, and a method for mounting the blade using this flange to ensure correct positioning.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If exterior markers are used on the blade to indicate pitch orientation, then alignment guidance is provided, but the markers are difficult to apply accurately and often result in incorrect mounting
Solution Approach 1:
The marking function is segmented from the blade structure and transferred to the pitch bearing. The pitch bearing is divided into a stationary part and a rotating part, with markers placed on the stationary part and reference features on the rotating part. This segmentation allows accurate markers to be applied to the stationary component during manufacturing, eliminating the difficulty of applying markers to the rotating blade.
Solution Approach 2:
The pitch bearing serves as an intermediary component between the blade and the hub. It includes reference features (markers, keys, or positioning elements) that mediate the alignment process. These reference features on the pitch bearing interact with corresponding features on the blade root to ensure accurate pitch angle positioning during assembly, transferring the alignment function from the blade exterior to the mounting interface.
2Reliability
If exterior markers are used on the blade, then pitch orientation indication is provided, but incorrect mounting still occurs leading to decreased energy yield and increased loads
Solution Approach 1:
Alignment reference features are preliminarily incorporated into the pitch bearing during its manufacturing process. Markers are applied to the stationary part and positioning features (such as keys or dimples) are formed on the rotating part before final assembly. This preliminary preparation ensures that when the blade is installed, accurate alignment is achieved through the pre-configured reference features, eliminating the need for complex field alignment procedures.
Solution Approach 2:
The alignment process is transformed from a manual mechanical marking operation on the blade to a mechanical feature-based positioning system. Instead of relying on painted or marked lines that require manual interpretation, the invention uses physical mechanical features (keys, dimples, protrusions, or recesses) on the pitch bearing that provide tactile and visual guidance for precise alignment during assembly.
3Productivity
If the blade is mounted with inaccurate pitch alignment, then installation is completed, but energy yield decreases and unintended loads increase
Solution Approach 1:
The pitch bearing incorporates reference features that provide immediate feedback during the assembly process. When the blade root is positioned on the pitch bearing, the reference features (markers for visual alignment, keys for mechanical positioning) provide real-time feedback on the pitch angle orientation. This feedback mechanism ensures that correct alignment is achieved before final tightening, preventing incorrect installation that would lead to reduced energy yield or increased loads.
Data Source
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AI summary
A method of manufacturing a wind turbine blade for a horizontal axis wind turbine (2), and mounting it to the pitch bearing of a hub of a wind turbine is described. The method comprises the steps of: manufacturing (402) a first wind turbine blade shell part; manufacturing (404) a second wind turbine blade shell part; assembling (406) at least the first wind turbine blade shell part and the second wind turbine blade shell part to form at least part of a shell body of the wind turbine blade, wherein the wind turbine blade extends between a root end and a tip end, and wherein the first wind turbine blade shell part and the second wind turbine blade shell part are at least adhered to each other along a first bond line that extends to the root end of the wind turbine blade; providing (408) a ring-shaped root end flange, which is configured to be connected to the root end of the shell body, and which is configured with a bond line marker, preferably on an inner circumference of the ring-shaped root end flange, and further configured with a pitch-angle marker; attaching (410) the ring-shaped root end flange to a root end face of the shell body, such that the ring-shaped root end flange covers the first bond line, and the bond line marker is aligned with the first bond line; and mounting (412) the wind turbine blade including the ring-shaped root end flange to the pitch bearing of the hub of the wind turbine, such that the pitch-angle marker is aligned with a zero-pitch position for the pitch bearing.