Dwell Cycle Crank S-Shaped Cam Efficiency
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Solution Overview
Problem
Conventional internal combustion engines suffer from inefficiencies due to potential heat loss and sub-optimal energy conversion, resulting in low efficiency, typically around 20%, mainly because of mistimed ignition and heat loss between the piston cylinder and engine block, limiting power production.
Innovation Solution
The dwell cycle crank incorporates an S-shaped cam and connecting bearing to create dwells and faster strokes, maximizing volumetric and geometric efficiencies by optimizing the crank cycle, allowing for quicker charge intake, higher compression ratios, and peak pressure application at advantageous angles.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If conventional crank geometry is used, then device complexity is low, but engine efficiency is low (around 20%) due to heat loss and sub-optimal energy conversion
Solution Approach 1:
The cam profile is segmented into distinct phases: intake stroke, dwell period, compression stroke, and power stroke. This segmentation allows each phase to be optimized independently, with the dwell period allowing complete combustion before power extraction, thereby increasing engine efficiency without excessive complexity
Solution Approach 2:
The cam profile is designed to be non-uniform, with varying speeds during different strokes. The dwell cycle crank creates faster strokes during power generation and slower strokes during compression and intake, dynamically optimizing the energy conversion process to improve efficiency
2Power
If faster piston strokes are implemented, then power production increases, but heat loss increases and combustion completeness decreases
Solution Approach 1:
The dwell cycle crank implements periodic action by creating alternating fast and slow strokes. During the power stroke, the piston moves fast to extract maximum power, while during compression and intake, slower speeds allow for more complete combustion and reduced heat loss, repeating this cycle for optimal performance
Solution Approach 2:
The dwell period ensures continuous useful action by maintaining optimal combustion conditions throughout the power stroke. The dwell phase allows the combustion process to complete fully before the power extraction begins, ensuring that energy conversion is continuous and efficient rather than interrupted by premature or incomplete combustion
3Productivity
If dwell cycles are introduced, then volumetric and geometric efficiencies increase, but device complexity increases due to S-shaped cam and connecting bearing
Solution Approach 1:
The S-shaped cam profile merges the functions of the cam mechanism and the connecting bearing into a single integrated component. This unified design achieves the dwell cycle effect while minimizing the number of separate parts, thereby reducing overall device complexity while maintaining improved volumetric efficiency
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 configuration enhances engine efficiency by achieving faster piston strokes, increased volumetric and geometric efficiencies, and more complete combustion, potentially doubling the efficiency of conventional engines.
Implementation Method 1
an offset journal disposed between the connecting bearing and the crankshaft to thereby form a torque arm
Data Source
AI summary
The dwell cycle crank includes a reciprocating piston having a piston head or cylinder, a main body connected to the piston head, a cap detachably mounted to the main body, an S-shaped cam formed between the main body and the cap, a follower disposed in the S-shaped cam, a rotatable crankshaft, and an offset journal disposed between the connecting bearing and the crankshaft to thereby form a torque arm. The S-shaped cam and connecting bearing create periodic dwells and faster strokes in the crank cycle to maximize volumetric and geometric efficiencies of the engine.