Scroll Compressor Oldham Ring Key Design
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Solution Overview
Problem
Conventional Oldham ring configurations in scroll compressors result in insufficient strength due to high contact pressure and increased moment on keys, leading to decreased strength of the housing and orbiting scroll facing surface, with the sealing ring potentially hindering key groove formation.
Innovation Solution
The Oldham ring design features a first key that protrudes radially inward from the ring portion, increasing the sliding surface area and reducing contact pressure, allowing the key groove to be formed without notching the housing, and enabling easy attachment along an oblique direction, thus preventing strength reduction and accommodating a sealing ring.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If the keys protrude perpendicular to the ring portion surface, then the Oldham ring structure is simple, but the sliding area is small and contact pressure is high
Solution Approach 1:
The key structure transitions from a single-direction protrusion (perpendicular to surface) to a multi-dimensional configuration with both radial and axial protrusions. This dimensional expansion creates a larger contact surface area between the key and key groove, distributing the load and reducing contact pressure while maintaining structural simplicity.
2Stress or pressure
If the keys protrude radially outwardly, then the sliding area increases, but the moment applied to the keys increases and housing strength decreases
Solution Approach 1:
Instead of uniformly protruding all keys radially outwardly, the invention applies different protrusion characteristics to different keys. The first keys have radial protrusions while the second keys have axial protrusions. This localized differentiation allows the sliding area to be increased where needed while minimizing the moment arm and reducing the impact on housing strength.
Solution Approach 2:
Rather than having all keys protrude in the same direction (radially outward), the invention uses keys protruding in opposite directions (some radially outward, some axially). This inversion of the conventional approach balances the moment distribution and reduces the overall stress on the housing structure.
3Ease of manufacture
If the key groove is formed on the orbiting scroll facing surface, then the Oldham ring can be attached, but the effective area of the facing surface decreases and contact pressure increases
Solution Approach 1:
The key groove is positioned not only on the orbiting scroll facing surface but also extends to the back surface of the facing portion. This multi-surface positioning allows the Oldham ring to be securely attached while distributing the groove occupation across different surfaces, preserving the effective contact area of the orbiting scroll facing surface.
4Ease of manufacture
If the housing is notched to accommodate radially protruding keys, then the keys can be positioned, but the housing strength decreases
Solution Approach 1:
The invention extracts the radial protrusion requirement from all keys and applies it only to specific keys (first keys), while other keys (second keys) use axial protrusions. This selective extraction eliminates the need for notching the housing, as the axial protrusions can be accommodated without compromising housing structural integrity.
Data Source
Figure 1
Figure 2~3
Figure 4~5
AI summary
A first key (54) of an Oldham ring (50) adjacent to a housing (23) in a scroll compressor is provided so as to protrude from a ring portion (53) toward the housing (23) and further protrude in a radially inward direction of the ring portion (53). A flange of the housing (23) is provided with a facing portion (71) having an orbiting scroll facing surface (70), and an annular opening (72) formed around the orbiting scroll facing surface (70) and housing the ring portion (53). A first key groove (61) is formed in a position adjacent to the back surface of the facing portion (71) so as to extend radially inwardly from the annular opening (72).