Wind Turbine Pitch System Mass Reduction via Beam Actuation
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Solution Overview
Problem
The increasing size of wind turbine blades necessitates larger and heavier pitch system components, leading to a proportional increase in mass, which is undesirable for mass reduction goals.
Innovation Solution
A pitch system design featuring parallel load transfer beam arrangements and linear actuators, with a flexible coupling between inner and outer bearing rings, allowing for a stiff connection while reducing mass and maintaining structural integrity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If the size of wind turbine blades is increased to capture more wind energy, then the energy capture capability is improved, but the mass of pitch system components increases proportionally
Solution Approach 1:
The pitch system is divided into separate functional components: inner bearing ring, outer bearing ring, load transfer beam arrangements, and actuator systems. This segmentation allows each component to be optimized independently for mass efficiency while maintaining overall system performance for larger blades
Solution Approach 2:
The load transfer beam arrangements are configured in parallel spatial arrangements, distributing loads across multiple dimensions rather than concentrating them in single heavy components. This dimensional distribution reduces the mass of individual pitch system components while maintaining the structural integrity needed for larger blades
2Strength
If larger pitch system components are used to support larger blades, then the structural strength is improved, but the mass of the pitch system increases
Solution Approach 1:
The pitch system employs composite structural arrangements combining bearing rings, beam sections, and actuator systems with distributed load paths. This composite approach achieves the required structural strength for larger blades without requiring proportional increases in component mass
Solution Approach 2:
The load transfer beam arrangements are pre-configured in parallel configurations that distribute loads before they reach the bearing rings. This preliminary load distribution prevents the need for overly massive bearing components, maintaining structural strength while reducing overall pitch system mass
3Measurement precision
If a stiff connection is maintained between bearing rings for accurate pitch actuation, then the pitch control precision is improved, but the bearing wear increases
Solution Approach 1:
Load transfer beam arrangements are introduced as intermediary elements between the inner and outer bearing rings. These beams provide the necessary stiff connection for accurate pitch actuation while mediating the load transfer to reduce direct contact stresses and wear on the bearing rings
Solution Approach 2:
The system replaces direct mechanical coupling of bearing rings with a beam-mediated connection system. This substitution maintains the stiff connection required for pitch control precision while distributing mechanical stresses to reduce bearing wear and extend component life
Data Source
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AI summary
A pitch system for rotating a blade of a wind turbine relative to a hub. The pitch system comprises a blade bearing including an inner bearing ring and an outer bearing ring, wherein the outer bearing ring is rotatable relative to the inner bearing ring, and an actuator system configured to control relative rotational movement between the inner bearing ring and outer bearing ring, comprising. The actuator system comprises a first load transfer beam arrangement spanning at least first and second fixing positions associated with the inner bearing ring, a second load transfer beam arrangement spanning at least first and second fixing positions associated with the outer bearing ring, and a first linear actuator coupled between the first load transfer beam arrangement and the second load transfer beam arrangement. A benefit of the pitch system of the invention is that it achieves a reduction in mass yet retains a stiff connection between the hub and an associated blade. Therefore, larger and heavier blades can be coupled to the pitch system whilst mitigating a proportional increase in mass of the pitch system.