Non-Circular Piston Engine With Ringless Sealing and Domed Combustion
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Solution Overview
Problem
Internal combustion engines with circular cross-section pistons and cylinders face inefficiencies due to space and weight constraints, limited overhead space for valves and injectors, reliance on lubrication systems, and suboptimal flame propagation and force transfer during combustion.
Innovation Solution
The development of internal combustion engines with non-circular cross-section pistons and cylinders, featuring a domed piston head and a ringless fluid sealing system, along with a multi-stage telescoping poppet valve and a crankshaft assembly using pins/keys instead of splined elements, to enhance power-to-weight ratio, reduce lubrication needs, and improve combustion efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If circular cross-section pistons and cylinders are used, then the engine structure is simple and manufacturing is easier, but the engine weight increases and power-to-weight ratio decreases
Solution Approach 1:
The patent applies asymmetry by transitioning from circular to non-circular (rectangular or square) piston and cylinder cross-sections. This asymmetric shape reduces the perimeter-to-area ratio, allowing smaller piston skirts for the same displacement, which reduces engine weight while maintaining manufacturing feasibility through standardized molding processes.
2Device complexity
If circular cross-section pistons are used, then the piston structure is simple, but the overhead space for valves and injectors is limited
Solution Approach 1:
The non-circular cross-section (rectangular or square) provides larger surface area and more favorable geometry for overhead component placement compared to circular sections of equivalent displacement. The increased perimeter and optimized shape factors allow greater space for intake valves, exhaust valves, auxiliary valves, spark plugs, glow plugs, fuel injectors, and water injectors.
3Reliability
If conventional piston rings and lubrication systems are used, then sealing is effective, but maintenance requirements increase
Solution Approach 1:
The patent extracts and eliminates piston rings from the sealing system, replacing them with a ringless fluid sealing mechanism. The non-circular piston geometry creates natural sealing through fluid pressure distribution and contact surface geometry, removing the need for removable piston rings and associated lubrication maintenance.
4Productivity
If hemispherical or domed piston heads are used, then flame propagation and force transfer are optimized, but the piston manufacturing complexity increases
Solution Approach 1:
The patent combines the non-circular cross-section geometry with a domed or hemispherical piston head configuration. This composite geometric approach optimizes both combustion efficiency (through improved flame propagation and force transfer from the domed shape) and maintains manufacturing feasibility through integrated molding processes that can produce complex three-dimensional shapes.
Data Source
AI summary
Internal combustion engines having a split crankshaft are disclosed. The engines may also have non-circular, preferably rectangular, cross-section pistons and cylinders. The pistons may include a skirt with a field of pockets that provide a ringless, non-lubricated, seal equivalent. The pistons also may have a domed piston head with depressions thereon to facilitate the movement of air/charge in the cylinder. The engines also may use multi-stage poppet valves in lieu of conventional poppet valves. The engines may use the pumping motion of the engine piston to supercharge the cylinder with air/charge. The engines also may operate in an inverted orientation in which the piston is closer to the local gravitationally dominant terrestrial body's center of gravity at top dead center position than at bottom dead center position.