Compression Ring Groove Recesses for Piston Ring Lift-Off
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Solution Overview
Problem
Internal combustion engines face challenges in reducing the force required for compression rings to lift off the lower groove flank, which affects gas and oil flushing efficiency, due to the existing force equilibrium in piston rings.
Innovation Solution
Introducing recesses into the lower groove flank of the ring grooves and/or lower ring flank of the piston rings, allowing for axial unloading and pressure compensation between the upper and lower ring flanks, thereby reducing the force needed for the piston rings to lift off the groove flank.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the piston ring is kept in contact with the lower groove flank during the entire working cycle, then the gas-tight sealing is maintained, but the flushing with fresh gas and oil is insufficient
Solution Approach 1:
The invention employs periodic action by designing the compression ring to periodically lift off the lower groove flank during the working cycle. This periodic lifting allows fresh gas and oil to flush through the ring groove, improving cleaning efficiency while maintaining gas-tight sealing during the compression stroke when the ring contacts the groove flank.
2Productivity
If the compression ring is lifted off the lower groove flank, then the flushing with fresh gas and oil is improved, but the force required for lifting increases the energy consumption
Solution Approach 1:
The invention applies pneumatic principles by utilizing pressure differences between the upper and lower sides of the compression ring to facilitate lifting. The recess in the lower groove flank creates a pressure differential that reduces the lifting force required, thereby improving flushing efficiency while minimizing energy consumption.
3Force
If a recess is introduced into the lower groove flank, then the pressure compensation is improved and lifting force is reduced, but the device complexity increases
Solution Approach 1:
The invention applies segmentation by introducing a recess into the lower groove flank, dividing the groove into distinct regions. This segmentation creates a pressure compensation chamber that reduces the lifting force required for the compression ring, achieving force reduction with minimal additional complexity.
Solution Approach 2:
The invention applies local quality by modifying only the lower groove flank region where the recess is introduced. This localized modification creates the pressure compensation effect exactly where needed, reducing lifting force without significantly increasing overall device complexity.
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 recesses facilitate easier lifting of the piston rings, enhancing gas-tight sealing and preventing excessive oil from entering the combustion chamber by reducing the required force for lifting, thus improving engine operation efficiency.
Implementation Method 1
Between the upper ring flank and the lower ring flank of the respective piston ring, a pressure compensation can thus be brought about, as a result of which the required force for lifting the piston ring off the lower groove flank of the respective ring groove is reduced.
Data Source
AI summary
A cylinder of an internal combustion engine, having a cylinder liner and a cylinder piston guided in the cylinder liner The cylinder piston has multiple ring grooves delimited by ring webs and are separated by the ring webs. Each ring grooves receives a compression ring or an oil scraping ring. Each ring groove is delimited by an upper groove flank, a lower groove flank and a groove base, and each piston ring has a lower ring flank, an upper ring flank a ring back and a section which rests against a radially inner running surface of the cylinder liner. A depression is introduced into the lower groove flank of the at least one ring groove or each ring groove which receives a compression ring and/or into the lower ring flank of the piston ring designed as a compression ring.