Variable-Compression Engine Eccentric Linkage for Uniform Cylinders
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Solution Overview
Problem
Existing multi-cylinder internal combustion engines, particularly two-row configurations, face challenges in achieving a uniform compression ratio across all cylinders due to the design of the crankshaft mechanism with a control arm, which limits the ability to set and maintain the same compression ratio in each cylinder during operation.
Innovation Solution
A mechanism for varying the compression ratio is introduced, featuring a control arm rod with eccentricities and coupling elements that allow for opposite rotation directions of neighboring eccentrics, ensuring a consistent compression ratio across all cylinders. This mechanism includes variants with control shafts, toothed wheels, and lubrication channels to facilitate the adjustment and synchronization of piston movement.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a crankshaft mechanism with control arm is used in a multi-cylinder engine, then the engine can operate with multiple cylinders, but it becomes impossible to achieve the same compression ratio in all cylinders during operation
Solution Approach 1:
The patent applies dynamics by making the compression ratio adjustable during operation. The control arm rod can rotate to different positions, dynamically changing the compression ratio for different cylinders. This allows the system to adapt the compression ratio for each cylinder independently while maintaining multi-cylinder operation, resolving the contradiction between productivity and compression ratio uniformity.
Solution Approach 2:
The patent segments the control mechanism by providing separate control arms for different cylinder rows (first row and second row cylinders). Each control arm can be independently positioned, allowing independent compression ratio adjustment for each cylinder or row of cylinders. This segmentation enables precise control over compression ratio uniformity across all cylinders while maintaining multi-cylinder operation.
2Productivity
If the piston path in the expansion stroke is extended to optimize performance, then engine efficiency improves, but the mechanism complexity increases
Solution Approach 1:
The control arm rod serves multiple functions: it controls the compression ratio adjustment and simultaneously manages the piston movement path. By integrating these functions into a single mechanism, the patent achieves extended piston path for optimized expansion stroke without proportionally increasing mechanism complexity. The same rotating control arm rod that adjusts compression ratio also influences piston trajectory, demonstrating multi-functionality that resolves the contradiction between productivity and device complexity.
Data Source
AI summary
Combustion engine with a variable compression ratio which, according to the invention, includes the following items: engine body, crankshaft with crank pins mounted rotatably in the body, cylinders, pistons connected to the crankshaft via pin connecting rod sand control arms as well as the control arm rod located inside the engine body, with eccentrics mounted on it, on which eccentrics for each piston there are separately mounted control arms, it is characterized by the fact that on the control arm rod (19) aside from the rigidly mounted eccentrics (18), on which single control arms (14) are rotatably mounted, there are also rotatably mounted eccentrics (23), on which single control arms (14) are rotatably mounted, where preferably on the eccentrics (18) are mounted the control arms (14) for one row of cylinders (5), while for the eccentrics (23) are mounted the control arms (14) for the other row of cylinders (5), additionally the engine contains a mechanism for changing the compression ratio consisting of the control arm rod (19) with eccentrics (18, 23) mounted on the control arm rod (19) as well as coupling elements that connect the elements of the mechanism which ensure that neighboring eccentrics (18, 23) rotate in opposite directions.