Split Roller Bearing Outer Ring With Self-Aligning Saw-Tooth Joint
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Solution Overview
Problem
Conventional methods for aligning the outer ring halves of split roller bearings face challenges such as requiring precise openings for dowels or screws, lack of mechanical connection leading to wedging apart, and complexity from using shrouds or thick rings, especially when allowing for axial movement.
Innovation Solution
A saw-tooth configuration with cooperating contact surfaces forming facets and angles between 15 and 55 degrees, allowing for self-alignment and secure engagement via screws or bolts, using electro-discharge-machining (EDM) to create consistent or varying thickness cuts.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If dowels or joint screws are used to align the two outer ring halves, then accurate alignment is achieved, but precise openings must be formed within the respective outer ring halves to receive the dowels or joint screws
Solution Approach 1:
The outer ring is divided into two halves with a split, allowing each half to be manufactured separately and then assembled. The segmentation enables the use of simpler manufacturing processes for each half while achieving accurate alignment through the cooperative geometry of the split surfaces.
Solution Approach 2:
The split surfaces feature an asymmetric W-shaped configuration with facets at specific angles (15-55 degrees) rather than a simple radial split. This asymmetric geometry provides self-aligning characteristics that ensure accurate positioning of the two halves without requiring precisely formed openings for fasteners.
2Ease of manufacture
If the outer ring is divided into two approximately equal parts via a V-shaped split, then the two halves can rest against each other, but there is no mechanical connection securing the two halves together, resulting in the two halves wedging apart in the housing
Solution Approach 1:
The split surfaces are pre-configured with W-shaped facets at specific angles before assembly. This preliminary geometric configuration ensures that when the two halves are brought together, the facets automatically guide and secure them in the correct aligned position, preventing wedging apart without requiring additional mechanical connection elements.
Solution Approach 2:
The split surfaces incorporate curved or angled facets rather than flat surfaces, creating a geometry that naturally guides the two halves into proper alignment and maintains stability. The faceted W-shape provides a self-locking effect that prevents the halves from separating or misaligning during operation.
3Stability of the object's composition
If a shroud is provided to surround the outer ring to support alignment of the two halves, then alignment in axial and radial directions is maintained, but a layer of complexity is added to the process
Solution Approach 1:
The alignment and stabilization functions that would traditionally require a separate shroud component are extracted and integrated directly into the split surfaces of the outer ring halves themselves. The W-shaped faceted geometry inherently provides the alignment and stabilization functions, eliminating the need for additional structural elements.
Solution Approach 2:
The alignment, stabilization, and mechanical connection functions are merged into the split surface geometry itself. The faceted W-shaped split surfaces simultaneously provide alignment guidance, mechanical interlocking, and stabilization, combining multiple functions into a single structural feature rather than requiring separate components.
4Manufacturing precision
If keyways and dowels are used to line up the two halves, then alignment is achieved to machining tolerances, but it is challenging to provide for them in hard materials and machining features when the material is in a soft state loses accuracy upon heat treatment
Solution Approach 1:
The invention changes the geometric parameters of the split surfaces, using W-shaped facets at specific angles (15-55 degrees) instead of traditional radial splits or keyways. This parameter change allows the features to be formed in hard materials without the same manufacturing challenges, as the faceted geometry can be created through methods like wire EDM that work effectively with hardened steel.
Solution Approach 2:
The traditional mechanical alignment system using keyways and dowels is replaced with a faceted geometric system. Instead of relying on inserted mechanical elements, the alignment is achieved through the precise geometry of the split surfaces themselves, which can be directly formed in the bearing material without separate assembly steps.
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
Ensures accurate and stable alignment of outer ring halves with reduced manufacturing precision requirements, minimizing misalignment errors to less than 5 microns, even with minor cutting inaccuracies.
Implementation Method 1
using electro-discharge-machining (EDM) to create consistent or varying thickness cuts
Data Source
AI summary
An outer ring (5) of a split roller bearing comprising: two generally semi-circular parts (15, 16) dis-engageably engageable together to form a generally circular component via a plurality of respective co-operating contact surfaces in a saw-tooth configuration; each said respective co-operating contact surface forming a facet (21, 22, 23, 24); intersections of said facets forming peak lines (20, 26) and trough lines (25, 27) of said saw-tooth; wherein each intersection (peak or trough) line forms a respective first angle to a plane normal to the axis of the ring, and wherein each facet forms a respective second angle to a plane containing the axis of the ring. At least one of the respective first angles is between 15 and 55 degrees.