Innovations for Increasing the Foundation Strength of Wind Turbines

Hollow wind turbine blade design with a reinforced structure that enables manufacturing with simplified fabrication steps and reduced cost while providing improved strength and stiffness. The blade has elongated reinforcing structures extending along the blade length, with each structure formed from a stack of pre-cured pultruded composite strips. The reinforcing structures are positioned within the blade shell halves and connected by an intersecting web.

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A wind turbine comprises a pitch bearing with variable thickness reinforcing plates along its circumference to reduce stress concentration and optimize the design for varying loads. The pitch bearing connects the turbine blades to the hub and pitches the blades. The reinforcing plates are bolted onto the bearing rings. The plates gradually thicken from the ends toward the center in a wedge shape. This provides additional strength only where needed.

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Wind turbine with a tensioning system to increase the stiffness and fatigue resistance of pitch bearings that connect the blades to the hub. The system involves tensioning elements that exert radial compression on the outer ring of the pitch bearing. This reduces deformations and stress concentrations in the bearing, improving its load transfer capabilities and preventing premature failures. The tensioning elements are anchored to the hub or blade and apply an adjustable radial compression force to the bearing when tensioned.

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A low-cost, high-strength, and stable wind turbine support structure that reduces oscillations and can be used in more locations. The structure uses tensioned single wires rather than strands or cables. This provides stability in wind and seismic events without the need for large towers or additional land for guy cables. The tensioned wires support the turbine mast and absorb forces.

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A wind turbine pitch bearing that improves the durability and performance of pitch bearings in wind turbines. The pitch bearing has variable thickness reinforcements attached to the bearing rings. The reinforcements are plates that are thicker at the ends and taper towards the center. This concentrates on extra strength where the bearing experiences the most stress. The variable thickness reinforcements enable using smaller, lighter bearings compared to uniform thickness designs.

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A reinforced wind turbine blade can be reinforced while suppressing possible stress concentration resulting from a load imposed on the blade root portion of the wind turbine blade in the flap direction. The blade has an outer surface of the blade root portion that is covered with an FRP reinforcing layer containing a plurality of fiber layers impregnated with resin. The reinforcing layers taper at both ends in the longitudinal direction of the blade root. This avoids sharp thickness variations that cause stress concentration. Laminating the fiber layers on an intermediate layer bonded to the blade surface can improve integration and reinforcement.

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Mechanical reinforcement of large wind turbine blades made from composite materials to increase the size range and operating speeds of wind turbines. The reinforcement is achieved without increasing blade thickness, weight, or inertia. It involves integrating pre-shaped pultruded rods or profiles into the blade during manufacture. These rods are made of high-strength carbon fibers that can develop compression resistances beyond 1,600 MPa. The rods act as internal reinforcements to provide additional structural strength to the blade without increasing thickness, weight, or inertia.

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A method of making wind turbine blades with integrated load-bearing reinforcing strips that address the challenges of handling long, heavy pultruded strips. The method involves using a specialized feed apparatus to dispense the coiled pultruded strips into the blade mold. The feed apparatus confines the coil to prevent uncoiling. This allows feeding the strip into the mold while it uncoils in place. By fixing the coil and feeding from the free end, the potential energy is released safely.

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A wind turbine blade with reinforced blade root to improve fatigue life and strength while minimizing stress concentration. The blade root section is covered with a tapered fiber-reinforced polymer (FRP) layer. The FRP layer has multiple fiber layers impregnated with resin that are laminated onto the blade root surface. The ends of the fiber layers taper to smoothly blend with the blade surface. This avoids sharp thickness transitions that cause stress concentration. The tapered FRP layer reinforces the blade root without creating stress risers.

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Wind turbine blade design that improves load transfer and avoids root failure when mounting long blades to turbine hubs. The blade root has embedded elongated fasteners like bushings, with metal fibers extending out from the fasteners into the composite material. These fibers reinforce the root and prevent fastener pullout.

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Wind turbine blade reinforcement that mitigates delamination caused by trapped air pockets during infusion. The reinforcement consists of tapered strips with longitudinally extending slots at the tapered end. When stacked in a blade spar cap and infused with resin, any trapped air cannot propagate through the slots, limiting delamination to localized areas.

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A reinforced wind turbine blade root design and manufacturing process that improves load distribution and avoids damage propagation. The blade root comprises an annular reinforcing element with threaded holes that alternate with coupling portions. This connects longitudinal reinforcing elements in the blade root composite material. The threaded holes can be used to attach the blade root to the hub. The reinforcing structure improves load balancing and reduces stress concentration that can cause blade damage.

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A spar cap for a wind turbine blade that extends along at least a portion of the blade span. The spar cap comprises a composite beam formed from preform layers. Each preform layer contains multiple collimated strength rods arranged longitudinally adjacent to each other in a single layer. The rods are made of straight fibers in a resin matrix. The single layer arrangement enables close packing and efficient resin flow during fabrication. The rigid rods provide high stiffness and compressive strength to support blade loads.

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Wind turbine blade with external reinforcing rods to prevent blade deformation and failure. The blade comprises a shell with an aerodynamic profile and elongated rods connected from outside to increase blade strength. The rods extend between the suction and pressure sides of the blade, preventing deformation when subjected to high wind loads. The rods have heads that fit through holes in the blade shell allowing them to be retrofitting externally.

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A fiber-reinforced composite sheet with enhanced strength and impact resistance for applications like windmill blades. The sheet has a main body with protruding ridges on one side. The sheet contains resin-impregnated fiber bundles, but crucially also unimpregnated fiber bundles at the ridge surfaces. This configuration allows the ridge portions to be infused with resin after molding to create a reinforced composite. The unimpregnated fibers act as a reinforcement skeleton within the resin-infused ridges, significantly boosting strength and impact resistance compared to a fully resin-impregnated sheet.

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