Three-Piece Oil Control Ring Layout for Lower Piston Friction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional piston oil control rings experience significant friction losses in internal combustion engines, which hinder efficiency.
Innovation Solution
A three-piece piston oil control ring design featuring a disc-shaped scraping ring, a disc-shaped stabilising ring, and an expander with axially protruding projections, where the expander maintains axial spacing between the rings, ensuring only the scraping ring contacts the cylinder inner surface, thereby minimizing friction from the stabilising ring.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If a conventional one-piece scraper ring with two scraping rails is used, then oil scraping function is provided, but friction losses are significant
Solution Approach 1:
The scraper ring is divided into three separate components: an upper scraping ring, a lower stabilizing ring, and an expander spring. This segmentation allows the upper ring to perform oil scraping with minimal friction while the lower ring provides structural stability without contacting the cylinder surface, thereby reducing overall friction losses.
Solution Approach 2:
The friction-generating scraping rails are extracted and concentrated solely on the upper scraping ring, while the lower stabilizing ring is designed to float above the cylinder surface. This extraction eliminates unnecessary friction from the lower ring, reducing energy losses.
2Loss of energy
If a three-piece scraper ring with two thin disc-shaped scraping rings is used, then uniform scraping effect is achieved, but friction is increased due to both rings contacting the surface
Solution Approach 1:
Different parts of the three-piece ring system have different functions: the upper ring is designed for oil scraping with a specific scraping edge, while the lower ring is designed for structural support without surface contact. This local differentiation ensures uniform scraping effect is achieved by the upper ring alone, while the lower ring provides stability without adding friction.
Solution Approach 2:
Only the upper scraping ring makes contact with the cylinder surface to perform the scraping function, while the lower stabilizing ring maintains a non-contact position. This partial action approach ensures that friction is minimized to only what is necessary for effective oil scraping.
3Stability of the object's composition
If the stabilizing ring exerts high pressure on the cylinder inner surface, then structural stability is improved, but friction increases
Solution Approach 1:
The stabilizing function is extracted and separated from the scraping function. The lower stabilizing ring provides structural support and prevents expander tilting without contacting the cylinder surface, thereby providing stability without generating friction.
Solution Approach 2:
The expander spring acts as an intermediary between the upper and lower rings, maintaining their axial spacing and ensuring proper positioning. This allows the lower ring to provide structural support without direct surface contact, decoupling stability from friction generation.
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 design reduces frictional resistance by limiting contact to only the scraping edge of the upper ring, significantly decreasing the frictional component contributed by the lower stabilising ring, thus enhancing engine efficiency.
Implementation Method 1
an expander, which can be in the form of for example a circular, corrugated, flat metal strip and has axially protruding projections on the inside
Data Source
AI summary
A three-piece piston oil control ring 2 has an upper, disc-shaped scraping ring 4, a lower, disc-shaped stabilising ring 6, and a circular expander 8 which has projections 10 protruding in the axial direction on an inner face. The circular expander 8 is arranged between the upper scraping ring 4 and the lower stabilising ring 6, wherein the projections 10 each bear inwardly against an inner face 14 of the scraping ring 4 or against an inner face 16 of the stabilising ring 6. An outer radius 18 of the scraping ring 4 is greater than an outer radius 20 of the lower stabilising ring 6, so that there is a radius difference δ between the scraping ring 4 and the stabilising ring 6.