Piston Sealing System Using Turbulent Fluid Pockets
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Solution Overview
Problem
Internal combustion engines face challenges with lubricant-based sealing systems, including wear, contamination, maintenance costs, and unwanted emissions due to lubricant leaks, which necessitate a reduction in or elimination of piston lubrication.
Innovation Solution
A contact-less or semi-contact-less sealing system utilizing a piston with laterally spaced pockets on its surface, where a working fluid at elevated pressure creates a seal equivalent through turbulence, reducing friction and eliminating the need for lubricants.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If lubricant-based sealing systems are used between piston and cylinder, then sealing effectiveness is improved, but wear, contamination, and maintenance requirements increase
Solution Approach 1:
The patent extracts and eliminates the lubricant from the sealing system, replacing it with a dry sealing mechanism using a compliant piston ring that deforms under pressure to create a seal against the cylinder wall without requiring any lubricating substance
Solution Approach 2:
The patent replaces the mechanical lubrication system with a pressure-based sealing mechanism where high-pressure gas directly acts on the piston ring to force it against the cylinder wall, substituting mechanical friction-based sealing with pressure-driven sealing
2Loss of energy
If lubricant is used to lubricate piston-cylinder interface, then friction is reduced, but lubricant leaks and emissions increase
Solution Approach 1:
The patent removes lubricant entirely from the system, eliminating the source of emissions while maintaining low friction through a compliant piston ring design that minimizes contact stress and allows smooth movement against the cylinder wall
Solution Approach 2:
The piston ring serves itself by using the high-pressure working gas to force itself against the cylinder wall, creating both the sealing action and the low-friction contact condition simultaneously without requiring external lubricant supply
3Reliability
If active lubrication system with pumps and passages is implemented, then piston lubrication is improved, but system complexity and maintenance costs increase
Solution Approach 1:
The patent extracts and removes the entire active lubrication system including pumps, passages, and control mechanisms, replacing it with a passive sealing approach where the working fluid pressure itself creates the sealing force
Solution Approach 2:
The high-pressure working fluid serves multiple functions simultaneously: it provides the sealing force on the piston ring, drives the piston motion, and maintains the seal without requiring separate lubrication system components
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 solution minimizes frictional losses, reduces maintenance, and enhances reliability by eliminating the need for lubricants, while maintaining effective sealing and self-centering capabilities within the engine.
Implementation Method 1
a seal equivalent is produced from working fluid interaction with the field of pockets
Data Source
AI summary
A piston and cylinder arrangement is disclosed in which a field of spaced pockets is provided on the walls of a piston skirt and/or the cylinder to create a seal equivalent between the piston and the cylinder. The pockets may be provided in a pattern having a plurality of vertically spaced rows.