Variable Compression Ratio Engine Mechanism
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Solution Overview
Problem
Existing internal combustion engines lack the ability to variably adjust compression ratios and integrate features like Otto's intake air flow throttling control and Diesel's constant pressure ignition within a balanced centrifugal rotating mechanism, limiting their efficiency and adaptability to different fuels.
Innovation Solution
The SOWDA engine design incorporates a mirror-image planetary-gear assembly and gear-pin assembly to vary the top dead center position of the piston, allowing for adjustable compression ratios, long power and exhaust strokes, and short intake and compression strokes, combined with Otto and Diesel cycle principles, enabling efficient operation on various fuels.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If a conventional crankshaft and fixed piston stroke design is used, then the engine structure is simple and reliable, but the compression ratio cannot be adjusted and energy efficiency is limited
Solution Approach 1:
The patent applies dynamics by replacing the fixed crankshaft mechanism with a variable compression ratio mechanism that allows the piston's top dead center position to be adjusted dynamically. This enables the compression ratio to change during operation, optimizing energy efficiency for different operating conditions while maintaining a mechanically sound structure through controlled variability rather than fixed geometry.
Solution Approach 2:
The invention implements parameter changes by enabling continuous adjustment of the compression ratio parameter through the variable compression ratio mechanism. The piston stroke length and top dead center position are modified as variable parameters rather than fixed dimensions, allowing the engine to adapt to different fuel types and operating requirements, thereby improving energy efficiency without requiring multiple fixed-design engines.
2Adaptability or versatility
If fixed compression ratio and fixed piston stroke are used, then the engine design is straightforward, but adaptability to different fuels and operating conditions is poor
Solution Approach 1:
The patent achieves universality by designing an engine mechanism that can handle multiple fuel types (gasoline, diesel, alternative fuels) and operating conditions through its variable compression ratio capability. The same engine structure can be adjusted to optimize performance for different fuels by changing the compression ratio, eliminating the need for separate fixed-design engines for each fuel type or application.
Solution Approach 2:
The variable compression ratio mechanism introduces dynamic adjustability to the engine design, allowing real-time or operational changes in compression ratio to match different fuel properties and operating requirements. This dynamic capability provides versatility across fuel types and applications while maintaining a single unified engine architecture rather than requiring multiple specialized designs.
3Use of energy by moving object
If long power stroke and short compression stroke (Atkinson cycle) are implemented, then thermal efficiency improves, but the mechanism becomes more complex
Solution Approach 1:
The patent merges the benefits of the Atkinson cycle (long power stroke, short compression stroke) with the flexibility of variable compression ratio in a single integrated mechanism. Rather than requiring separate mechanisms for fixed Atkinson cycle operation and variable compression adjustment, the invention combines these functions into one unified variable compression ratio system that can achieve extended power strokes with reduced compression strokes while maintaining adjustability across different operating conditions.
Data Source
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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 (1), a gear-pin assembly (20), and a piston-and-connecting rod assembly (27). The mirror-image planetary-gear assembly (1) includes a first planetary-gear assembly (2) and a second planetary-gear assembly (3); wherein each includes a sun gear (4), a primary planet gear (5), a plurality of secondary planet gears (6), and a ring gear (7). The first planetary-gear assembly (2) and the second planetary-gear assembly (3) are mounted along a main rotation axis, offset from each other and mirroring each other. The gear-pin assembly (20) is eccentrically connected between the primary planet gears (5). Resultantly, rotating the sun gears (4) alters the orientation of the gear-pin assembly (20), and thus changing the top dead center height.