Wind Turbine Flexible Hub Coupling Reduces Bending Loads
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional wind turbines face maintenance challenges due to high and fluctuating loads on gearboxes, which are exacerbated by bending loads transmitted from the blades and hub, leading to premature wear and complex installation processes.
Innovation Solution
A wind turbine design that reduces bending load transmission to the rotor shaft by using flexible elements with adjustable stiffness, allowing for easier installation and maintenance, and incorporating a reduced part count, with flexible elements made from materials like elastomers or metal-elastomer combinations to absorb misalignment and distribute loads effectively.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional rigid coupling with multiple bolts is used to connect hub and rotor shaft, then torque transmission is reliable, but installation is time-consuming and expensive, and misalignment causes stresses and fatigue problems
Solution Approach 1:
The coupling stiffness parameter is changed from rigid to flexible, allowing the coupling to adapt to misalignment while maintaining torque transmission. The flexible elements provide the necessary compliance to absorb manufacturing tolerances and simplify alignment during installation.
Solution Approach 2:
Flexible elements are introduced as intermediary components between the hub and rotor shaft, acting as a mediator that transmits torque while accommodating misalignment. This intermediary layer eliminates the need for precise alignment and reduces installation time.
2Strength
If rigid coupling is used to ensure precise torque transmission, then connection strength is high, but bending loads are transmitted to the rotor shaft and gearbox causing premature wear
Solution Approach 1:
The stiffness parameter of the coupling is modified by introducing flexible elements, which changes the load transmission characteristics. The flexible coupling maintains sufficient strength for torque transmission while filtering out harmful bending loads through its compliance.
Solution Approach 2:
The flexible elements convert the harmful bending loads into beneficial elastic deformations, absorbing the shock and fluctuating loads that would otherwise damage the rotor shaft and gearbox. The flexibility that was needed for alignment now also serves to protect against load transmission.
3Reliability
If multiple bolts and flexible elements are used in the coupling, then torque transmission is reliable, but the part count increases complicating logistics and installation
Solution Approach 1:
Multiple flexible elements and bolts are merged into an integrated coupling assembly, reducing the number of separate parts that need to be managed in logistics. The flexible elements are incorporated as integral components of the coupling mechanism, simplifying the overall part count.
Solution Approach 2:
The flexible elements serve multiple functions simultaneously: they provide torque transmission, accommodate misalignment, and protect against bending loads. This multi-functionality reduces the need for separate components, thereby reducing the overall part count and simplifying logistics.
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
Significantly reduces bending loads on the rotor shaft and gearbox, simplifies the installation process, and decreases the part count, thereby enhancing maintenance efficiency and reducing the risk of fatigue-related issues.
Implementation Method 1
The flexible elements may be made from any suitable material, e.g. elastomer materials, or combinations of metals with elastomers or yet other suitable materials. The elements may obtain their flexible properties due to their shape, material, positioning, mounting or combinations of these.
Implementation Method 2
Bolts provided in elastic bushings are used to connect the centre piece to the hub. The elastic bushings make the coupling more flexible in the longitudinal direction of the rotor shaft.
Data Source
Figure 1
Figure 2
Figure 3~4
AI summary
Wind turbine comprising a hub (10) with one or more blades, said hub (10) being rotatably mounted on a frame (20) and operatively coupled to a shaft (30), wherein said shaft (30) is provided at least partially internally of said frame (20), and wherein, a centre piece (40) from which a plurality of spokes (44) extend substantially radially is mounted on said shaft (30), and wherein the hub (10) is provided with a plurality of circumf erentially arranged axial protrusions (14), and wherein flexible elements (42) are arranged to connect the spokes (44) to said protrusions (14).