Conical Oil Scraper Ring Structure to Eliminate Axial Play
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Solution Overview
Problem
Conventional oil scraper rings suffer from axial play, allowing oil to enter the combustion chamber due to gaps between the piston ring and scraper ring flanks, leading to inefficient oil scraping, especially under low pressure conditions, and are costly and difficult to manufacture and install compared to one- or two-part designs.
Innovation Solution
An axial-play-free oil scraper ring design featuring elastic upper and/or lower piston ring flank legs that taper inwardly, forming conical surfaces, with scraper webs and oil channels to ensure effective oil scraping without axial play, and optionally incorporating an expander spring for increased form-filling capability and reduced twisting.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional one- or two-part oil scraper rings are used, then manufacturing and installation costs are lower and handling is easier, but axial play exists causing gaps between flanks and piston ring groove, allowing oil to enter the combustion chamber
Solution Approach 1:
The piston ring is divided into three parts: an intermediate leg (running surface leg) and two flank legs (upper and lower piston ring flank legs). This segmentation allows the flank legs to be elastic and taper inwardly, forming conical surfaces that eliminate axial play and gaps with the piston ring groove flanks, ensuring reliable oil scraping while maintaining a manageable structure
Solution Approach 2:
Only the flank legs are made elastic with conical tapering, while the intermediate leg maintains the running surface and scraper webs. This localized elasticity ensures contact with the groove flanks to eliminate gaps, while preserving the scraping function and avoiding making the entire ring overly complex
2Reliability
If three-part oil scraper rings are used, then oil scraping effectiveness is excellent with no gaps between flanks and groove, but manufacturing and installation costs increase and handling becomes more difficult
Solution Approach 1:
The three parts (intermediate leg and two flank legs) are combined into a single integrally formed piston ring with continuous material flow. This merging eliminates the need for separate assembly of multiple parts, reducing manufacturing complexity and installation difficulty while maintaining the oil scraping effectiveness of the three-part design
Solution Approach 2:
Instead of making the intermediate leg elastic to achieve form-filling, the invention makes the flank legs elastic. This inversion allows the elastic elements to contact the groove flanks and eliminate gaps, while the rigid intermediate leg maintains the running surface, simplifying both manufacturing and installation
3Reliability
If elastic flank legs with conical surfaces are used, then axial play is eliminated and oil scraping is improved, but the ring requires pretensioning and insertion into a corresponding groove
Solution Approach 1:
The elastic flank legs are pre-formed with conical tapering during manufacturing, creating built-in pretension. This preliminary action allows the ring to be inserted into the piston ring groove without requiring additional tensioning tools or complex installation procedures, while still achieving the gap-free contact with groove flanks
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 ensures reliable oil scraping without axial play, reduces manufacturing and installation costs, and maintains effective form-filling capability while minimizing twisting and wear, enhancing operational efficiency and ease of handling.
Implementation Method 1
the upper and/or the lower piston ring flank leg are/is elastic. The upper and/or the lower piston ring flank leg are/is elastic and taper(s) inwardly in the radial direction, and their/its piston ring flank(s) essentially form(s) a conical surface in an uninstalled state
Data Source
AI summary
A play-free oil scraper ring has a cross section with a running surface leg having at least one scraper web that is situated on a running surface, an upper piston ring flank leg that is connected to the running surface leg, and the upper surface of which forms an upper piston ring flank. A lower piston ring flank leg is likewise connected to the running surface leg, the lower surface of which forms a lower piston ring flank. The upper and/or the lower piston ring flank leg are/is elastic, taper(s) inwardly in the radial direction, and their/its piston ring flank(s) essentially form(s) a conical surface in an uninstalled state. The uninstalled piston ring has an axial height that exceeds a width of a piston ring groove for which the piston ring is intended.