Wind Turbine Rotor Blade Fastening Device with Locking Nut
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Solution Overview
Problem
Existing fastening systems for rotor blades in wind turbines face issues with reliable and reversible attachment, as self-locking nuts can detach over time, and existing solutions for securing the connection either prevent detachment but hinder maintenance or allow detachment but compromise reliability.
Innovation Solution
A fastening device comprising an expansion bolt with a first and second threaded section, a fastening nut, and a locking nut that exerts greater clamping force, along with a shim washer and locking wire, ensuring secure attachment while allowing for easy disassembly and reassembly, thereby providing a reliable and reversible connection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If adhesive is used to secure the connection between fastening nuts and threaded sections, then the connection reliability is improved, but the reversibility for maintenance is lost
Solution Approach 1:
A locking nut is introduced as an intermediary component between the fastening nut and the threaded section. The locking nut provides mechanical interlocking through its locking element (such as a deformable ring or elastomeric material) that engages with the threaded section, preventing loosening without requiring adhesive. This intermediary component maintains connection reliability while allowing the fastening nut to be removed for maintenance by simply unscrewing it from the threaded section.
2Reliability
If lock nut is used to secure the fastening nut position, then the connection reliability is improved, but the self-locking mechanism is eliminated
Solution Approach 1:
The locking nut combines multiple functions into a single component: it provides mechanical interlocking through its locking element, maintains the fastening nut's position, and preserves self-locking capability through its threaded engagement with the expansion bolt. The locking element (deformable ring or elastomeric material) deforms during tightening to create friction and mechanical interference, providing self-locking without requiring separate locking mechanisms that might eliminate this property.
3Object-affected harmful factors
If fastening nuts are tightened with reduced torque to protect rotor blade material, then the material damage risk is reduced, but the connection reliability deteriorates
Solution Approach 1:
The locking nut acts as a mediator that enhances the connection reliability without requiring increased tightening torque on the fastening nut. The locking element in the locking nut provides mechanical interlocking and friction that prevent loosening, allowing the fastening nut to be tightened with reduced torque while maintaining adequate connection reliability. This protects the rotor blade material from damage while ensuring secure fastening.
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 ensures a secure and reliable attachment of rotor blades to the rotor hub, preventing loosening of the fastening nut while allowing for maintenance and reattachment, with the locking nut's design enabling easy detachment and reattachment without damaging the rotor blade material.
Implementation Method 1
the locking nut exerting a greater clamping force on the second threaded section than the fastening nut
Data Source
Figure 1~2
Figure 3~4
Figure 5~6b
AI summary
The present invention discloses a fastening device for attaching a rotor blade (10) to a rotor hub (20) of a wind turbine, comprising: - an expansion bolt (30) which can be passed through a fastening opening (22) of a rotor hub flange (21) with a first end threaded section (31) and a second end threaded section (32), wherein the first threaded section (31) is designed for connection with a threaded bore (12) provided in the rotor blade (10);and - a fastening nut (40) that can be screwed onto the second threaded section (32), wherein the fastening device is characterized in that it further comprises a locking nut (50) that can be screwed onto the second threaded section (32) and can be brought into contact at least indirectly with the fastening nut (40) screwed onto the second threaded section (32), wherein the locking nut (50) exerts a greater clamping force on the second threaded section (50) than the fastening nut (40);