Segmented Roller Bearing Rim Reduces Hertzian Pressure
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Tapered roller bearings with straight ribs experience high surface pressure and poor lubrication due to small contact ellipses, while those with spherical ribs are sensitive to misalignment, leading to edge stresses and poor guidance.
Innovation Solution
A roller bearing design featuring a spherical rim section with an adjacent opening rim section, where the spherical section ensures low Hertzian pressure and adequate guidance, and the opening section reduces contact ellipse size and misalignment sensitivity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stress or pressure
If spherical ribs are used in roller bearings, then Hertzian pressure is reduced and roller guidance is improved, but sensitivity to misalignment increases leading to edge stresses
Solution Approach 1:
The rim surface is segmented into two distinct zones: a spherical rim surface section and an opening rim surface section. This segmentation allows each zone to serve different functions - the spherical section provides low Hertzian pressure and guidance, while the opening section reduces misalignment sensitivity and prevents edge stresses
Solution Approach 2:
Different regions of the rim surface are given different geometric properties. The spherical rim surface section has a specific radius of curvature optimized for low contact pressure, while the opening rim surface section has a different radius that reduces sensitivity to misalignment. This local differentiation of surface properties resolves the contradiction between pressure reduction and misalignment sensitivity
2Ease of manufacture
If straight ribs are used in roller bearings, then manufacturing is simplified and misalignment tolerance is increased, but surface pressure and Hertzian pressure become excessively high
Solution Approach 1:
The invention introduces spherical curvature to the rim surface by providing a spherical rim surface section with a specific radius of curvature. This curvature reduces the Hertzian pressure compared to straight ribs while maintaining manufacturing feasibility through standardized spherical surface generation processes
3Ease of operation
If spherical ribs with high sensitivity to misalignment are used, then roller guidance during running is improved, but contact point definition becomes unstable under misalignment conditions
Solution Approach 1:
The rim surface is divided into spherical and opening sections, where each segment handles different aspects of roller interaction. The spherical section provides guidance while the opening section stabilizes the contact point under misalignment, resolving the contradiction between guidance quality and contact point stability
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
The design maintains roller guidance, reduces Hertzian pressure, and minimizes the contact ellipse's overlap with the rim, making the contact point less sensitive to misalignments and preventing edge stresses.
Implementation Method 1
the roller-rib contact has a higher surface pressure (Hertzian pressure) between the roller end face 21 and this compared to spherical ribs facing board surface
Implementation Method 2
A characteristic stress distribution (surface pressure) occurs on the contact surface in both bodies, with the stress always being highest in the middle
Data Source
Figure 1
Figure 2
Figure 3
AI summary
The invention relates to a bearing race (3) for a rolling bearing, having a raceway (14; 15) for at least one roller (13) comprising a roller end face (21) having a first curvature and implemented as a partial sphere, wherein the bearing race comprises a lip (31) disposed at the end face of the roller (13) for deflecting axial forces and having a lip surface (32) facing the roller end face, wherein the lip surface (32) comprises a spherical lip surface segment (33) having a second curvature, wherein the first and the second curvature are selected in order to obtain a first gap dimension (d1) between the spherical roller end face (21) and the spherical lip surface segment (33), and wherein the lip surface (32) additionally comprises an opening lip surface segment (34) having a curvature less than the second curvature for a greater gap dimension (d2) between the roller end face (21) and the opening lip surface segment (34).