Three-Part Oil Scraper Ring Curvature for Groove-Base Oil Deflection
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Solution Overview
Problem
Existing oil scraper rings do not effectively improve scraping properties, particularly in conveying oil towards the groove base, and suffer from issues like oil coke formation and increased friction due to uniform scraper ring designs and expander spring configurations.
Innovation Solution
The design of oil scraper rings with a ring body having an upper and lower flank, where the upper flank has a curvature that smoothly transitions into a straight section and an upper radius, and the lower flank is symmetrically spherical, allowing for efficient oil deflection towards the groove base, with an MF expander spring maintaining axial distance between the scraper rings.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a uniform scraper ring design with expander spring is used, then the contact force is distributed uniformly over the entire circumference, but the oil scraping efficiency towards the groove base is insufficient
Solution Approach 1:
The scraper ring features an asymmetric cross-sectional design where the outer contour includes a curved section with radius of curvature R that is significantly smaller than the half-height of the scraper ring (R < H/2). This asymmetric geometry creates a pivot point that generates rotational moment, causing the scraper ring to tilt and deflect oil towards the groove base, thereby improving scraping efficiency and reducing oil coke formation compared to uniform symmetric designs.
Solution Approach 2:
The scraper ring incorporates a curved outer contour section with a specific radius of curvature R that is smaller than the half-height H of the scraper ring. This curvature creates a pivot point at distance R from the cylinder inner surface, generating a rotational moment that tilts the scraper ring to effectively deflect oil towards the groove base, improving oil scraping performance.
2Productivity
If the radius of curvature of the ring outer contour is made smaller than the half height of the scraper ring, then oil is deflected more effectively towards the groove base, but the friction increases
Solution Approach 1:
The scraper ring design allows the scraper ring to dynamically tilt and rotate during operation. The curved outer contour with radius R < H/2 creates a pivot point that enables the scraper ring to adjust its orientation based on operating conditions, optimizing the balance between oil deflection efficiency and friction reduction through dynamic adaptation rather than static geometry alone.
3Reliability
If a three-part scraper ring with MF spring is used, then the axial distance between scraper rings is maintained, but the complexity of the device increases
Solution Approach 1:
The three-part scraper ring design uses an MF spring that automatically maintains the axial distance between the two scraper rings through its inherent elastic properties. The spring self-adjusts to maintain optimal spacing without requiring external control mechanisms, thereby maintaining reliability while managing structural complexity through self-regulating behavior.
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
This configuration enhances oil scraping efficiency, reduces friction, and minimizes oil coke formation by optimizing the curvature and transitions of the scraper rings, ensuring effective oil capture and transport during piston movement.
Implementation Method 1
the expander spring is configured as an MF spring, wherein the upper scraper ring has a curvature at the pivot point which goes over continuously and smoothly into the lower flank
Implementation Method 2
the ring outer contour has a radius of curvature R which is smaller than the height H of the lower or upper scraper ring by a factor between 1.5 to 6, preferably between 3 to 5 times
Data Source
AI summary
A three-part oil scraper ring includes an upper scraper ring (24), a lower scraper ring (26), wherein the scraper rings (24, 26) are held at a distance by an expander spring (34) and pressed radially outwards. The upper scraper ring (24) has a ring body (4) having an upper flank (6), a lower flank (8), a ring inner surface (10) and a ring outer surface (12) which has a ring outer contour (14) in cross-section in axial direction (A). The ring body (4) has a height H which, when viewed in axial direction (A), corresponds to the greatest distance of the upper flank (6) from the lower flank (8). The ring outer contour (14) forms a running surface (16) which has a radius of curvature R which is smaller than the height H of the upper scraper ring (24) by a factor between 1.5 to 6.