Wind Turbine Rotor Blade Layout for Lower Pitch Bearing Loads
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Modern wind turbines face challenges with high bearing friction and loads due to large rotor blades, leading to increased costs and limited rotor blade length due to high pitch bearing loads and complex hub machining requirements.
Innovation Solution
The rotor blade design features a carrier with a flange and a pitch bearing spaced towards the blade tip, reducing tilt moments on the pitch bearing by balancing area moments, allowing for smaller pitch bearings and increased free travel between the rotor blades and the tower, thus reducing costs and enabling longer blades.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If the pitch bearing is arranged directly on the blade root, then the connection structure is simplified, but the tilt moment on the pitch bearing increases significantly leading to high bearing friction and large bearing sizes
Solution Approach 1:
The pitch bearing is moved from the blade root (inner end) toward the blade tip along the blade span, changing the spatial dimension of the bearing arrangement. This dimensional shift creates a more favorable moment arm distribution, where the area moment from the blade root to the pitch bearing partially compensates the area moment from the pitch bearing to the blade tip, significantly reducing the resultant tilt moment on the pitch bearing.
2Force
If larger pitch bearings are used to handle high tilt moments, then the bearing can support higher loads, but the bearing friction increases and larger pitch drives are required
Solution Approach 1:
The pitch bearing is pre-positioned at an optimized location along the blade span during design, rather than at the blade root. This preliminary spatial arrangement creates a moment-balancing configuration that reduces the tilt moment before it acts on the bearing, allowing smaller bearings with lower friction to be used while still handling the required loads.
3Length of moving object
If the rotor blade length is increased, then the power generation capacity increases, but the necessary free travel between the rotor blades and tower surface is compromised
Solution Approach 1:
The pitch bearing and its carrier are positioned at an optimized longitudinal location along the blade span, creating a geometric configuration that increases the effective free travel distance between the rotor blade and tower surface. This spatial repositioning allows longer blades to be used while maintaining the required clearance.
4Manufacturing precision
If the rotor hub is machined precisely for accurate rotor blade fit, then the assembly precision is improved, but the manufacturing complexity and costs increase
Solution Approach 1:
The rotor blade assembly is segmented into distinct components: the blade itself, the flange, and the pitch bearing with carrier. This segmentation allows each component to be manufactured and assembled separately, reducing the need for complex precision machining of the rotor hub while maintaining accurate blade-to-hub alignment through the modular connection structure.
Data Source
AI summary
A wind-turbine rotor blade, comprising a blade root and a blade tip, a flange arranged on the blade root side for fastening the rotor blade to a rotor hub of a wind turbine, and a pitch bearing for adjusting the angle of attack of the rotor blade. The rotor blade has a non-pitched carrier, on which the flange is embodied, wherein the pitch bearing is fastened to the carrier and is spaced apart from the flange toward the blade tip.