Connecting Rod Eccentric Mechanism for Variable Compression Ratio
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Solution Overview
Problem
Existing variable compression ratio technologies face challenges in durability and sealing due to high hydraulic pressure requirements and the need for separate adjustment valve control cams, limiting the ability to efficiently adjust compression ratios based on vehicle operational states.
Innovation Solution
A connecting rod with an eccentric mechanism featuring a one-way clutch, which eliminates the need for high-pressure hydraulic support and omits the separate adjustment valve control cam, using balls, rollers, or needles on the eccentric cam's outer surfaces and cages to adjust the phase of the eccentric cam, allowing for stable compression ratio adjustment without high-pressure oil support.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If high-pressure hydraulic systems are used to support the eccentric cam, then the compression ratio can be adjusted, but durability and sealing properties deteriorate due to substantially high pressure requirements
Solution Approach 1:
The patent replaces the high-pressure hydraulic system with a mechanical one-way clutch mechanism. The one-way clutch allows the eccentric cam to rotate in one direction while preventing rotation in the opposite direction, enabling compression ratio adjustment without requiring high-pressure hydraulic support. This mechanical substitution eliminates the durability and sealing issues associated with high-pressure hydraulic systems.
Solution Approach 2:
The one-way clutch mechanism enables the eccentric cam to automatically adjust its position based on the direction of rotation, without requiring external high-pressure hydraulic control. The mechanism uses the engine's own operational forces to drive the phase adjustment, making the system self-sufficient and eliminating the need for complex high-pressure hydraulic infrastructure.
2Adaptability or versatility
If separate adjustment valve control cams are installed on the cylinder block, then the adjustment valve can be controlled to change compression ratio, but device complexity increases
Solution Approach 1:
The patent merges the adjustment valve control function directly into the connecting rod assembly by installing the one-way clutch mechanism on the eccentric cam, which is already part of the connecting rod. This eliminates the need for separate adjustment valve control cams on the cylinder block, reducing overall device complexity while maintaining the compression ratio adjustment capability.
Solution Approach 2:
The one-way clutch mechanism serves multiple functions: it enables compression ratio adjustment, eliminates the need for separate control cams, and integrates directly into the existing connecting rod structure. This multi-functionality reduces the number of separate components needed in the system.
3Adaptability or versatility
If two hydraulic cylinders are used to support the eccentric cam, then the phase can be adjusted, but the capacity of the oil pump increases and electrical load increases due to high-capacity electric motor requirements
Solution Approach 1:
The patent replaces the two hydraulic cylinders and high-capacity electric motor system with a mechanical one-way clutch mechanism. This substitution eliminates the need for high oil pump capacity and reduces electrical load, as the phase adjustment is achieved through mechanical means using the engine's operational forces rather than powered hydraulic actuators.
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 solution enhances engine durability and sealing quality while reducing manufacturing costs and complexity by allowing for stable compression ratio adjustment without the need for high-pressure hydraulic systems and separate adjustment valve control cams.
Implementation Method 1
a one-way clutch mechanism, which eliminates the need for high-pressure hydraulic support and omits the separate adjustment valve control cam, using balls, rollers, or needles on the eccentric cam's outer surfaces and cages to adjust the phase of the eccentric cam
Data Source
AI summary
A connecting rod is provided that includes an eccentric mechanism. The eccentric mechanism is installed at a connecting rod end of the connecting rod to change a height of a piston to change a compression ratio. Accordingly, the compression ratio is adjusted more stably by performing phase control.