Three-Piece Oil Scraper Ring Curvature for Groove Oil Return
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing oil scraper rings for internal combustion engines have limitations in achieving optimal wiping properties, particularly in conveying oil towards the bottom of the piston ring groove, with current designs relying mainly on slots and openings between scraper webs.
Innovation Solution
A three-piece oil scraper ring design featuring a ring body with distinct upper and lower flanks, an inner and outer surface, and a specific curvature profile that includes a radius of curvature smaller than the height, allowing for improved oil deflection and scraping efficiency, with an MF expander spring enhancing radial oil passage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a conventional radius of curvature (R ≥ H/2) is used for the running surface, then the ring structure is simpler and easier to manufacture, but the oil scraping performance is insufficient and oil cannot be effectively directed towards the bottom of the groove
Solution Approach 1:
The patent applies parameter changes by modifying the radius of curvature R of the running surface to be smaller than H/2 (specifically R between 0.05-0.15mm while H is 0.28-0.52mm). This parameter change transforms the geometric characteristics of the ring, enabling the running surface to effectively deflect oil towards the bottom of the groove, thereby resolving the contradiction between structural simplicity and scraping performance.
2Productivity
If the radius of curvature R is made very small to improve oil deflection, then oil scraping performance improves, but the ring becomes more complex and harder to manufacture
Solution Approach 1:
The patent optimizes the radius of curvature parameter to a specific range (R = 0.05-0.15mm) that balances scraping performance with manufacturability. This controlled parameter change ensures effective oil deflection while maintaining feasibility for precision manufacturing, avoiding excessive complexity.
Solution Approach 2:
The patent utilizes controlled curvature in the running surface with a specific radius R. This curvature design enables the running surface to act as an effective oil deflector, directing oil towards the groove bottom. The curvature is optimized to achieve the desired flow control without creating manufacturing infeasibility.
3Productivity
If slots and openings are added between scraper ribs to direct oil, then oil flow towards groove bottom improves, but the device complexity increases
Solution Approach 1:
The patent extracts the oil deflection function from the traditional slot/opening structure and relocates it to the running surface geometry. By shaping the running surface with a small radius of curvature, the oil deflection function is achieved without adding slots or openings, thereby reducing structural complexity while maintaining effective oil flow control.
Solution Approach 2:
The patent uses the curvature of the running surface (radius R < H/2) to perform the oil deflection function that would otherwise require slots or openings. The curved geometry naturally directs oil flow towards the groove bottom, achieving the same functional result with a simpler, more integrated structure.
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 enhances oil scraping performance by effectively directing oil towards the piston ring groove, reducing oil consumption and frictional losses, while preventing oil carbon deposits and maintaining efficient lubrication.
Implementation Method 1
two essentially disc-shaped or flat scraper rings or rails are held axially spaced apart by a spring and pressed radially outwards
Implementation Method 2
the outer contour of the ring has a radius of curvature R which is smaller by a factor of between 1.5 and 6, preferably between 3 and 5 times and more preferably between 3.5 and 4.5 times than the height H
Data Source
Figure 1~2
Figure 3
Figure 4~5
AI summary
The invention relates to a three-part oil scraper ring, comprising an upper scraper ring (24) and a lower scraper ring (26), wherein the scraper rings (24, 26) are maintained at a distance by an expander spring (34) and pressed radially outwards, wherein the upper scraper ring (24) has a ring body (4) with an upper side (6), a lower side (8), a ring inner surface (10) and a ring outer surface (12), which has a ring outer contour (14) in a cross-sectional view in the axial direction (A), wherein the ring body (4) has a height H corresponding to the greatest distance of the upper side (6) from the lower side (8) when viewed in the axial direction (A), wherein the ring outer contour (14) forms a running surface (16) having a radius of curvature R that is smaller than the height H of the upper scraper ring (24) by a factor of between 1.5 and 6.