Asymmetric Double-Row Self-Aligning Roller Bearing Load Sharing
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Solution Overview
Problem
Double-row self-aligning roller bearings face limitations in evenly distributing axial and radial loads between rollers, leading to uneven contact surface pressures and reduced service life due to dimensional constraints, particularly in applications like wind turbine generators.
Innovation Solution
The design incorporates rollers in two rows with specific contact angle ratios (0.25 < θ1/θ2 < 0.5) and distance ratios (0.5 ≤ B1/B2 ≤ 0.6) to distribute loads effectively, with the row having a larger contact angle supporting the axial load and the row with a smaller contact angle supporting the radial load, ensuring equalized contact surface pressures and increased load capacity within standard dimensions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If rollers of different lengths are arranged in two rows to increase load capacity, then the load capacity of rollers receiving axial load is improved, but the bearing width exceeds standard dimensional values
Solution Approach 1:
The patent changes the contact angle parameter of rollers to increase load capacity without increasing bearing width. Specifically, rollers in the second row are designed with a larger contact angle than rollers in the first row, allowing the bearing to accommodate axial loads while maintaining standard dimensional constraints.
2Strength
If the contact angle of rollers receiving axial load is increased to increase load capacity, then the load capacity is improved, but the inner diameter exceeds standard dimensional values
Solution Approach 1:
The patent optimizes the contact angle parameter within acceptable ranges to balance load capacity and dimensional constraints. By carefully selecting contact angles for different roller rows, the patent achieves sufficient load capacity while keeping the inner diameter within standard bearing dimensions.
3Device complexity
If axial load is concentrated on rollers in one row, then the bearing structure is simplified, but the contact surface pressure on those rollers increases causing shorter service life
Solution Approach 1:
The patent applies different contact angle characteristics to different roller rows to optimize load distribution. Rollers in the first row have a smaller contact angle suitable for radial loads, while rollers in the second row have a larger contact angle suitable for axial loads, creating local optimization that equalizes contact surface pressures and extends service life.
Solution Approach 2:
The patent introduces asymmetry in the bearing design by using rollers with different contact angles in different rows. This asymmetric configuration allows each roller row to be optimally suited for its specific load type, preventing excessive contact pressure on any single row and thereby extending the overall bearing service life.
Data Source
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AI summary
Provided is a double-row self-aligning roller bearing including: an inner ring; an outer ring having a spherical raceway surface; and rollers arranged in two rows and interposed between the inner ring and the outer ring, wherein a ratio of a contact angle θ1 in one row to a contact angle θ2 in the other row falls within a range of 0.25 ≤ θ1/θ2 ≤ 0.5, and a ratio of distance B1 in a bearing width direction from an end face of the bearing on a side of the one of the rows to an intersection of two lines of action defining the contact angles of the two rows, relative to a distance B2 in the bearing width direction from an end face of the bearing on a side of the other of the rows to the intersection falls within a range of 0.5 ≤ B1/B2 ≤ 0.6.