Offset-Gap Piston Ring Assembly for Hydrogen Blow-By Sealing
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Solution Overview
Problem
Internal combustion engines face challenges with hydrogen fuel due to high air/fuel concentration flammability and oil presence in the combustion chamber, leading to potential ignition and reduced engine efficiency.
Innovation Solution
A piston ring assembly comprising two annular ring elements with gaps that are out of alignment, twisted at an angle to prevent blow-by and oil leakage, and designed to self-center and lock securely to maintain efficient sealing and operation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a single piston ring with a gap is used, then assembly is easier and tension is provided, but blow-by occurs and fuel enters the crankcase
Solution Approach 1:
The single piston ring is divided into two separate annular ring elements, each with its own gap. This segmentation allows each ring to be independently assembled while collectively providing better sealing. The gaps are positioned at different angular locations to prevent simultaneous alignment, reducing blow-by while maintaining assembly ease of each individual ring.
Solution Approach 2:
The solution moves from a single-plane sealing approach to a multi-plane sealing approach by stacking two ring elements at different axial positions. The gaps are offset both axially and angularly, creating a three-dimensional sealing configuration that blocks gas flow paths more effectively than a single ring while maintaining manufacturing simplicity.
2Ease of operation
If piston rings with gaps are used, then assembly is facilitated and ring tension is provided, but gas flows through the gap causing blow-by
Solution Approach 1:
Dividing the sealing function into two separate rings with gaps at different angular positions creates a stepped sealing effect. Gas must navigate around the first ring's gap, then encounter the second ring's gap at a different location, significantly reducing blow-by and energy loss while preserving the assembly benefits of gapped rings.
Solution Approach 2:
The two annular ring elements are nested axially within the piston groove, with one ring positioned above the other. This nesting arrangement allows both rings to occupy the same radial space while maintaining axial separation, creating an efficient space-utilizing sealing system that minimizes gas leakage paths.
3Use of energy by moving object
If oil is present in the combustion chamber for lubrication, then friction is reduced, but oil ignites with hydrogen generating emissions
Solution Approach 1:
The piston ring assembly extracts and removes oil from the combustion chamber environment by providing enhanced sealing between the crankcase and combustion chamber. The two-offset-ring configuration prevents oil vapor and liquid oil from entering the combustion space, eliminating the source of harmful emissions while preserving necessary lubrication in the crankcase.
Solution Approach 2:
The design converts the potential harm of oil presence into benefit by using the second ring element as an additional sealing barrier that specifically targets oil vapor and liquid carryover. The offset gap configuration creates a labyrinth effect that traps oil particles and redirects them back to the crankcase, transforming a potential emission source into a controlled lubrication system.
4Loss of substance
If air/fuel mixture flows into the crankcase, then combustion byproducts are removed, but hydrogen ignites unexpectedly due to high flammability concentration
Solution Approach 1:
By positioning the two ring gaps at different angular and axial locations, the system creates a multi-dimensional barrier that prevents concentrated air/fuel mixtures from reaching the crankcase. Gas must diffuse through offset gaps rather than flowing directly, diluting the mixture to below flammability concentrations while still allowing combustion byproducts to be managed.
Solution Approach 2:
The second annular ring element acts as an intermediary barrier between the combustion chamber and crankcase. It provides an additional sealing layer that intercepts and redirects gas flows, preventing direct communication between chambers and eliminating the safety hazard of flammable mixture accumulation in the crankcase.
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 solution effectively minimizes blow-by and oil film presence in the combustion chamber, enhancing engine efficiency and ensuring safe operation with hydrogen fuel.
Implementation Method 1
reducing friction at the sliding contact to the inner face of the cylinder
Data Source
Figure 1
Figure 2~4
AI summary
The invention relates to a piston ring assembly (10) comprising a first annular ring element (15) having a first gap and further comprising a second annular ring element (16) having a second gap, the first annular ring element (15) is located above the second annular ring element (16) contacting the second annular ring element (16) such that the first gap and the second gap are out of alignment, the first annular ring element (15) having a first radial outer face (17) having a first outer radius (R1) and the second ring element (16) having a second radial outer face (18) having a second outer radius (R2) such that the second outer radius (R2) is larger or the same than the first outer radius (R1).