Wind Turbine Flexible Coupling for Bending Load Isolation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional wind turbines face issues with bending loads and deformations being transmitted from the rotor hub to the generator, leading to air gap variations and potential structural damage, especially in direct drive designs where these loads are not adequately mitigated, resulting in maintenance challenges and high costs due to the need for large and expensive generators.
Innovation Solution
The implementation of a wind turbine design where the rotor hub is rotatably mounted on a frame with axial protrusions extending into the generator rotor's carrying structure, coupled with flexible elements that reduce the transmission of loads other than torque, allowing for reduced bending loads and improved alignment stability, thereby minimizing deformations and air gap variations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a direct drive wind turbine design is used to eliminate the gearbox, then maintenance requirements are reduced, but bending loads and deformations are directly transmitted to the generator causing air gap variations and potential structural damage
Solution Approach 1:
The patent introduces an intermediary flexible coupling element between the rotor hub and generator rotor that selectively transmits torque while isolating bending loads. This mediator allows the drive train to achieve direct drive reliability without exposing the generator to harmful bending moments and deformations.
Solution Approach 2:
The flexible coupling exhibits different stiffness characteristics for different load types: it is stiff in the torsional direction to transmit torque effectively, but compliant in radial and axial directions to absorb bending loads and deformations, thereby protecting the generator from these harmful forces.
2Power
If a rigid coupling is used between rotor and generator rotor, then torque transmission is efficient, but bending loads and misalignments cause air gap variations and generator deformations
Solution Approach 1:
The coupling transitions from a static rigid connection to a dynamic flexible connection that adapts its stiffness characteristics based on operating conditions. The flexible elements allow real-time adjustment to accommodate misalignments and absorb deformations while maintaining effective torque transmission.
3Force
If the rotor hub is positioned far from the tower, then bending loads in the tower are reduced, but the distance between rotor and generator increases requiring a larger generator
Solution Approach 1:
The flexible coupling enables a change in the spatial parameter (distance between rotor hub and generator) without compromising torque transmission effectiveness. This allows the rotor hub to be repositioned closer to the tower, reducing tower bending loads, while the coupling compensates for the reduced distance to maintain proper generator coupling.
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
This design effectively reduces bending loads and deformations in the generator rotor, allowing for closer positioning of the rotor hub to the tower, minimizing air gap variations, and reducing maintenance and operational costs by using flexible couplings made from elastic or visco-elastic materials that absorb torsional and axial loads.
Implementation Method 1
flexible couplings made from elastic or visco-elastic materials that absorb torsional and axial loads
Implementation Method 2
flexible couplings made from elastic or visco-elastic materials that absorb torsional and axial loads
Data Source
AI summary
Wind turbine comprising a rotor and a generator, said rotor comprising a rotor hub and one or more rotor blades and said generator comprising a generator stator and a generator rotor, wherein the hub is rotatably mounted on a frame, the generator rotor comprises a carrying structure carrying magnetic or electromagnetic elements, one or more circumferentially arranged substantially axial protrusions are attached to said rotor, wherein said axial protrusions extend into the generator rotor carrying structure, and one or more flexible couplings are arranged between one or more of said axial protrusions and said carrying structure.