Wind Turbine Main Shaft Mounting Segments for Stress Reduction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Wind turbines face challenges in reducing stress concentration and cost associated with the connection of the hub portion to the main shaft, particularly due to the weight and material expense of the nose portion, which is typically made from the same high-strength alloy as the main shaft.
Innovation Solution
The introduction of metal mounting segments with varying thickness, shape, and fastening methods on the alignment portion of the main shaft to align and secure wind turbine components, such as the hub, with the central axis, reducing stress concentration and using less expensive structural steel for these segments.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the nose portion is fabricated from the same high-strength alloy as the main shaft, then the alignment function is ensured, but the weight and cost of the main shaft increase
Solution Approach 1:
The patent divides the nose portion into separate mounting segments that are coupled to the alignment portion of the main shaft. These segments are made from structural steel rather than the high-strength alloy used for the main shaft, thereby reducing weight while maintaining the alignment function through the segmented modular structure.
Solution Approach 2:
The patent employs composite material construction by using different materials for different parts: the main shaft is made from high-strength alloy (e.g., 42CrMo4) while the mounting segments are made from structural steel. This composite approach optimizes the overall structure by using materials appropriately matched to functional requirements, reducing total weight while maintaining reliability.
2Reliability
If the nose portion is fabricated from the same high-strength alloy as the main shaft, then the alignment function is ensured, but the cost of the main shaft increases
Solution Approach 1:
The nose portion is segmented into separate mounting segments that can be manufactured independently from structural steel and then coupled to the main shaft. This segmentation allows the expensive high-strength alloy to be used only where absolutely necessary (main shaft), while less expensive structural steel is used for the mounting segments, thereby reducing overall cost while maintaining alignment functionality.
Solution Approach 2:
The patent uses composite material construction with the main shaft made from high-strength alloy and mounting segments made from structural steel. This approach reduces material costs by applying expensive materials only where structurally necessary while using cheaper materials for non-critical components, thereby reducing overall manufacturing cost while maintaining reliability.
3Strength
If a bolted connection is used to connect the hub portion to the main shaft, then the connection is secure, but stress concentration occurs in the region
Solution Approach 1:
The patent applies local quality by providing reinforcement elements specifically at the coupling surface and mounting segment interfaces where stress concentration occurs. The mounting segments are designed with specific geometries and reinforcement features localized to the high-stress regions, while other parts of the structure maintain their original design, thereby addressing stress concentration without compromising overall connection strength.
Data Source
AI summary
The disclosure relates to a main shaft of a wind turbine with mounting segments. The main shaft includes a shaft portion and a disc portion. The disc portion includes a coupling surface, a hollow portion, and an alignment portion. The alignment portion is characterized by one or more mounting segments coupled with the alignment portion. The mounting segments are configured to align a component of the wind turbine with the central axis of the main shaft. Further, the one or more mounting segments are coupled to the alignment portion using at least one fastening device. The mounting segments have a thickness âtâ that may be constant or varied based on the component 32 of the wind turbine coupled to the main shaft.