Convex Raceway Roller Bearing Assembly to Reduce End Loading
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Solution Overview
Problem
Tapered roller bearing assemblies are difficult and expensive to manufacture, and they can experience undesirable end loading and stress profiles due to their frustoconical design, leading to potential spalling and bearing failure.
Innovation Solution
A roller bearing assembly utilizing a tapered inner and outer cup with a convex outer raceway profile and straight rollers, which are easier to manufacture and reduce end loading by maintaining contact with the raceway throughout rotation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If tapered rollers are used in the bearing assembly, then the bearing can handle both axial and radial loads, but the manufacturing complexity and cost increase significantly
Solution Approach 1:
The bearing assembly is segmented into two functional parts: straight rollers that are simple to manufacture, and a convex outer raceway profile that provides the tapered load handling capability. This segmentation allows each component to be optimized independently - the rollers for ease of manufacture and the raceway for performance.
Solution Approach 2:
Instead of tapering the rollers in three dimensions, the invention introduces a convex profile dimension to the outer raceway. This dimensional change in the raceway geometry creates the equivalent functional effect of tapered rollers while keeping the rollers themselves simple and straight.
2Adaptability or versatility
If frustoconical tapered rollers are used, then axial and radial loads are handled, but end loading and stress profiles occur leading to spalling and bearing failure
Solution Approach 1:
The convex profile is applied locally to the outer raceway surface at specific contact zones, creating localized stress distribution characteristics that prevent end loading. This local geometric modification ensures uniform contact pressure across the roller-raceway interface, eliminating the stress concentrations that lead to spalling.
3Ease of manufacture
If straight rollers are used with a convex outer raceway profile, then manufacturing cost is reduced and end loading is minimized, but the bearing must maintain proper contact geometry during rotation
Solution Approach 1:
The convex profile is pre-formed on the outer raceway during manufacturing, establishing the correct contact geometry in advance. This preliminary geometric configuration ensures that as the bearing operates and loads are applied, the rollers automatically maintain proper contact with the raceway without requiring additional adjustment or precision assembly.
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 use of straight rollers in a bearing assembly with a convex outer raceway profile reduces end loading and spalling, leading to improved durability and reduced manufacturing costs compared to tapered roller bearing assemblies.
Implementation Method 1
each straight roller is in rolling contact with the inner raceway and the outer raceway
Data Source
AI summary
A roller bearing assembly including an tapered inner cup defining an inner raceway, an tapered outer cup defining an outer raceway, the outer raceway having a convex profile, the convex profile being defined by an intersection of the outer raceway and a central plane in which a longitudinal center axis of the roller bearing assembly lies, and a plurality of straight rollers disposed between the tapered inner cup and the tapered outer cup so that each straight roller is in rolling contact with the inner raceway and the outer raceway, each straight roller having a first end face, a second end face and a cylindrical body extending therebetween.