Wind Turbine Blade Pitch Connection Plate Flexibility
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The repeated use of wind turbine blade pitch systems leads to mechanical fatigue, potentially causing catastrophic failures due to uneven load distribution and excessive forces on bolts, resulting in inconsistent pitch adjustments and reduced system reliability.
Innovation Solution
A wind turbine blade pitch system with a connection plate that features a central annular region with radial arms and semi-circular slots or grooves, allowing for flexibility and reduced stiffness, which dampens excessive forces and enhances the durability of bolts by reducing axial and torsional stiffness, and optionally using flexible spacers and longer bolts with reduced central diameters.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If the connection plate is made stiff to ensure structural stability, then the structural stability is improved, but the fatigue in bolts increases due to excessive forces being transmitted
Solution Approach 1:
The connection plate incorporates a flexible central annular region with radial arms and semi-circular slots that allow the plate to flex elastically. This flexibility absorbs excessive forces and reduces the transmission of stress cycles to the bolts, thereby reducing fatigue while maintaining overall structural stability through the rigid flange regions.
2Reliability
If the connection plate is made flexible to reduce bolt fatigue, then the bolt fatigue resistance is improved, but the structural stability deteriorates
Solution Approach 1:
The connection plate employs local quality by having different regions with different stiffness characteristics. The central annular region is made flexible with radial arms and semi-circular slots to reduce bolt fatigue, while the inner and outer annular flange regions remain stiff to maintain structural stability. This spatial differentiation of mechanical properties resolves the contradiction between flexibility and stability.
3Adaptability or versatility
If the radial arms in the central annular region are made longer to increase flexibility, then the flexibility is improved, but the structural strength deteriorates
Solution Approach 1:
The radial arms in the central annular region are designed with semi-circular slots that provide flexibility while maintaining structural integrity. The slots allow the arms to flex elastically under load, providing the needed adaptability without significantly compromising the overall structural strength, as the arms remain connected to the stiff flange regions.
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 fatigue in the blade pitch system components, preventing bolt fractures and ensuring consistent pitch adjustments, thereby enhancing the reliability and longevity of the wind turbine's blade pitch system.
Implementation Method 1
the central annular region is configured to flex relative to the inner and outer annular flange portions to reduce the stiffness of the connection plate between inner and outer annular flange portions
Data Source
Figure 1
Figure 2
Figure 3
AI summary
This invention concerns a wind turbine blade pitch system for rotating rotor blades 18 of a wind turbine 10 relative to a hub 20. The wind turbine pitch system comprises an actuating stem (38) moveable in an axial direction; a traverse holder 40; a traverse 42 rotatably mounted on the actuating stem 38, wherein the traverse 42 comprises a traverse arm 44 radially extending from the traverse holder 40; a connection plate 62 rotationally coupling the traverse 42 and the traverse holder 40; and, a crank arm 46 connected at one end to the traverse arm 44 and at another end to a rotatable pitch bearing 48 coupled to the rotor blade 18. The crank arm 46 is configured to convert the axial movement of the actuating stem 38 into a rotational movement of the rotor blade 18. The connection plate 62 comprises an inner annular flange region 78 secured to the traverse holder 40; an outer annular flange region 76 secured to the traverse 42; and, a central annular region 80 radially positioned between and connecting the inner and outer annular flange regions 78, 76. The central annular region 80 is configured to flex relative to the inner and outer annular flange portions 78, 76 to reduce the stiffness of the connection plate 62 between inner and outer annular flange portions 78, 76.