Oldham Coupling Fracture Resistance via Segmented Web
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Solution Overview
Problem
Oldham couplings in scroll compressors often experience fatigue failure due to wear of guides or keys, leading to reorientation and potential fracture, especially under poor lubrication conditions, with previous solutions focusing on reducing key wear through coatings rather than addressing the underlying structural issues.
Innovation Solution
The Oldham coupling design is enhanced with an annular ring featuring specific key and riding pad configurations to inhibit relative rotational movement between scroll members, improving fracture resistance independently of key wear, without using wear-resistant coatings and by optimizing the structural layout using finite element analysis.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If wear resistant coatings are applied to keys to reduce wear, then key wear is reduced, but the underlying structural issues and fracture resistance are not addressed
Solution Approach 1:
The Oldham coupling web is divided into multiple reinforcement regions with different thicknesses and structural configurations. The web includes a first region with a first thickness and a second region with a second thickness, creating segmented reinforcement zones that address stress concentration at specific locations without requiring complex coatings or multiple components.
Solution Approach 2:
Different regions of the web are given different local properties through varying thickness and structural reinforcement. The web includes a first region with a first thickness and a second region with a second thickness, allowing localized optimization of fracture resistance where stress concentration occurs, rather than uniformly strengthening the entire web.
2Strength
If the web structure is made thicker to improve fracture resistance, then fracture resistance is improved, but the overall device weight and complexity increase
Solution Approach 1:
The web is segmented into regions of different thicknesses, with only specific areas requiring additional reinforcement. This allows fracture resistance to be improved at critical locations without uniformly increasing the weight of the entire web structure.
Solution Approach 2:
The web has non-uniform thickness distribution with a first region having a first thickness and a second region having a second thickness. This local quality variation provides enhanced fracture resistance where needed while minimizing unnecessary weight in other areas.
3Stability of the object's composition
If keys are made longer or more prominent to prevent relative rotation, then rotational control is improved, but wear and stress concentration increase leading to fatigue failure
Solution Approach 1:
The web is divided into multiple reinforcement regions that work together to support the keys and distribute stresses. This segmentation allows for better stress distribution across the key-web interface, reducing wear and fatigue failure while maintaining rotational alignment stability.
Solution Approach 2:
The web structure combines different material properties through varying thickness and reinforcement configurations. This composite-like structure provides both the flexibility needed for key movement and the rigidity needed for rotational alignment, reducing wear and stress concentration.
Data Source
AI summary
A rotary compressor including a housing, a first scroll member, a second scroll member in meshing engagement with the first scroll member, and an Oldham coupling coupled to the second scroll member to inhibit the relative rotational movement between the first scroll member and the second scroll member. The Oldham coupling including a first riding pad, a second riding pad, a third riding pad is positioned, and a fourth riding pad positioned such that the first riding pad and the fourth riding pad are in an overlapping arrangement.