Differentiated Roller Geometry for Wind Turbine Bearing Load Management
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Double row self-aligning roller bearings in wind power generators face issues with unequal loads causing premature wear and reduced life, particularly due to high friction and edge stress in highly-loaded rollers and sliding in low-loaded rollers, leading to inefficient support and maintenance challenges.
Innovation Solution
The solution involves differentiating the length and curvature radius of spherical rollers in each row to match load conditions, with longer rollers in highly-loaded rows and shorter rollers in low-loaded rows, and optimizing the contact geometry between rollers and track surfaces to reduce edge stress and prevent skewing, thereby enhancing load-bearing capacity and extending bearing life.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If the spherical roller in the highly-loaded row uses a concave spherical configuration to prevent skewing, then the roller can maintain proper alignment, but the contact surface pressure increases causing high friction resistance and increased rotation torque
Solution Approach 1:
The patent applies different surface configurations to different rows of spherical rollers based on their specific load conditions. The first row (highly-loaded) uses a cylindrical configuration instead of concave spherical to reduce friction, while the second row (less-loaded) uses the concave spherical configuration for skew prevention. This local differentiation resolves the contradiction by optimizing each row's roller configuration for its specific operational requirements.
2Device complexity
If the spherical roller in the highly-loaded row contacts the center rib at the upper part of the side surface, then the structure is simple, but the contact ellipse is cut causing edge stress and premature wear or peeling
Solution Approach 1:
The patent differentiates the functional requirements of different rows by applying a cylindrical configuration to the first row's rollers, which prevents the contact ellipse from being cut and eliminates edge stress at the center rib contact point. This local modification to the roller geometry in the highly-loaded row resolves the reliability issue while maintaining structural simplicity.
3Quantity of substance
If the spherical roller in the low-loaded row is used, then the bearing size can be reduced, but sliding is generated between the roller and track surfaces causing surface damage and abrasion
Solution Approach 1:
The patent applies the concave spherical configuration specifically to the second row's spherical rollers, which are in the low-loaded position. This configuration increases the contact area between the roller and track surfaces, preventing sliding and the associated surface damage and abrasion. The local application of this configuration to the appropriate row resolves the contradiction between bearing size and surface integrity.
4Device complexity
If equal length spherical rollers are used in both rows, then the bearing structure is simple, but the highly-loaded roller has short rolling fatigue life while the low-loaded roller is over-designed
Solution Approach 1:
The patent differentiates the roller configurations between the two rows based on their load conditions. The first row uses cylindrical rollers for high-load capacity and fatigue resistance, while the second row uses concave spherical rollers for skew prevention and reduced friction. This local differentiation allows each row's rollers to be optimized for their specific operational demands, resolving the contradiction between structural simplicity and service life.
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 approach allows for appropriate load support in each row, reducing friction, edge stress, and skewing, resulting in a longer-lasting and more reliable main shaft support structure with improved durability and reduced maintenance needs.
Implementation Method 1
a self-aligning roller bearing suitable for rotatably supporting the main shaft of the wind power generator
Implementation Method 2
the contact surface pressure is high, so that friction resistance is generated and a rotation torque is increased
Data Source
AI summary
A double row self-aligning roller bearing in which spherical rollers are arranged in double rows between an inner ring and an outer ring, characterized in that the curvature radius of the ridge line of the spherical roller in one row is R1, the curvature radius of the ridge line of the spherical roller positioned in the other row is R2, the curvature radius of the inner ring track surface being in contact with the spherical roller in one row is N1, and the curvature radius of the inner ring track surface being in contact with the spherical roller in the other row is N2, a relation such that N1/R1>N2/R2 is satisfied.