Variable Compression Ratio Engine Mechanism
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Solution Overview
Problem
Current internal combustion engines lack the ability to variably adjust compression ratios and efficiently combine different stroke cycles, such as Otto, Diesel, Atkinson, and Moteki, within a compact and balanced mechanism, limiting their energy efficiency and adaptability to various fuels.
Innovation Solution
The SOWDA engine design integrates a mirror-image planetary-gear assembly with a gear-pin assembly, allowing for infinitely variable compression ratios and combining long power and exhaust strokes with short intake and compression strokes, using epicyclical gearing to control the top dead center position of the piston and adjust the compression ratio dynamically.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If conventional fixed compression ratio designs are used, then the engine structure is simple, but the energy efficiency and adaptability to various fuels are limited
Solution Approach 1:
The patent implements a dynamic compression ratio adjustment mechanism where the top dead center position of the piston is variable rather than fixed. This is achieved through a mirror-image planetary-gear assembly with gear-pin assemblies that can shift the piston's top dead center position, allowing the compression ratio to be changed during operation to optimize energy efficiency for different operating conditions and fuel types.
Solution Approach 2:
The engine design combines multiple cycle characteristics (Otto, Diesel, Atkinson, Moteki) into a single universal engine system. The variable compression ratio mechanism enables the engine to adapt to various fuel types and operating modes, making it universally applicable across different applications from lawn-tractors to airplanes.
2Power
If fixed stroke lengths are used, then the mechanism is simpler, but the ability to optimize power output and efficiency is reduced
Solution Approach 1:
The patent implements variable stroke lengths for different phases of the engine cycle. The power stroke and exhaust stroke are made longer than the intake and compression strokes, and this stroke length differentiation can be dynamically adjusted. This is achieved through the planetary-gear mechanism that controls the piston's top dead center position, allowing optimization of power output while maintaining efficient combustion.
3Adaptability or versatility
If variable compression ratio mechanism is added, then energy efficiency improves, but the device complexity increases
Solution Approach 1:
The patent merges the compression ratio control function with the existing crankshaft mechanism by integrating a mirror-image planetary-gear assembly into the engine's rotating mechanism. This combination allows the compression ratio to be varied without adding a completely separate control system, as the planetary-gear mechanism works in conjunction with the crankshaft to achieve both rotation and compression ratio adjustment.
Solution Approach 2:
The variable compression ratio mechanism is designed to be self-regulating through the mechanical properties of the planetary-gear system. The gear-pin assemblies and mirror-image planetary-gear assembly automatically adjust the piston's top dead center position based on the engine's operating conditions, reducing the need for complex external control systems while maintaining fuel adaptability.
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 enables high energy efficiency, adaptability to various fuels, and improved performance by allowing instantaneous adjustment of compression ratios, making it suitable for a wide range of applications from lawn-tractors to airplanes, with reduced energy losses and increased power output.
Implementation Method 1
using epicyclical gearing to control the top dead center position of the piston and adjust the compression ratio dynamically
Data Source
AI summary
A balanced and rotating mechanism of an internal combustion engine, which combines adjustable variable compression ratio with long power and exhaust strokes and short intake and compression strokes to obtain an internal combustion engine with variable air intake flow and maintain a constant pressure ignition. The mechanism includes a mirror-image planetary-gear assembly, a gear-pin assembly, and a piston-and-connecting rod assembly. The mirror-image planetary-gear assembly includes a first planetary-gear assembly and a second planetary-gear assembly; wherein each includes a sun gear, a primary planet gear, a plurality of secondary planet gears, and a ring gear. The first planetary-gear assembly and the second planetary-gear assembly are mounted along a main rotation axis, offset from each other and mirroring each other. The gear-pin assembly is eccentrically connected between the primary planet gears. Resultantly, rotating the sun gears alters the orientation of the gear-pin assembly, and thus changing the top dead center height.