Piston Pin Assembly for Dynamic Compression Ratio Adjustment
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Solution Overview
Problem
Existing solutions for dynamically adjusting the compression ratio in internal combustion piston engines are complex and unreliable, lacking a simple and well-controllable mechanism for varying the compression ratio during engine operation.
Innovation Solution
A piston pin assembly with offset central axes, featuring a rotatable eccentric sleeve and a coupling system that synchronizes the power transmission and locking mechanisms, allowing for selective locking and unlocking of the piston pin's rotational movement, enabling efficient adjustment of the compression ratio through a clutch system and hydraulic actuator.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If existing solutions for dynamically adjusting compression ratio are implemented, then compression ratio adjustment capability is improved, but device complexity increases and reliability decreases
Solution Approach 1:
The piston pin is divided into multiple functional segments: a first pin portion with a first central axis for connection to the piston, a second pin portion with a second central axis offset from the first axis to provide eccentricity for compression ratio adjustment, and a third pin portion for connection to the connecting rod. This segmentation allows each portion to perform its specific function while maintaining overall simplicity of the assembly.
Solution Approach 2:
The piston pin assembly serves multiple functions within a single component: it connects the piston to the connecting rod, provides rotational movement capability, enables compression ratio adjustment through eccentricity, and allows selective locking of the pin in different positions. This multi-functionality eliminates the need for separate mechanisms for each function.
2Adaptability or versatility
If existing solutions for dynamically adjusting compression ratio are implemented, then compression ratio adjustment capability is improved, but operational reliability worsens
Solution Approach 1:
The piston pin assembly is designed to automatically lock into specific positions during operation through its eccentric geometry and the interaction between the pin portions. The offset central axis creates natural stopping positions where the pin aligns with the piston and connecting rod, providing self-locking functionality without requiring additional locking mechanisms.
Solution Approach 2:
The piston pin is designed to rotate freely between the piston and connecting rod during normal engine operation, allowing dynamic adjustment of the compression ratio. The pin can rotate to different angular positions, each corresponding to a different compression ratio, enabling the system to adapt to varying operational requirements while maintaining reliability through simple rotational movement.
3Adaptability or versatility
If a locked pin is used to adjust compression ratio, then compression ratio control is improved, but ease of operation deteriorates
Solution Approach 1:
The piston pin is designed to rotate periodically between different angular positions during engine operation, with each position corresponding to a different compression ratio. The eccentric geometry creates natural periodic stopping positions where the pin aligns with the piston and connecting rod, allowing the system to cycle through different compression ratios automatically based on engine operation.
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
The solution provides a simple, reliable, and controllable means to adjust the compression ratio, optimizing engine performance for dual-fuel operation and addressing knocking limits, while ensuring smooth operation and efficient power transmission.
Implementation Method 1
the first and the second ends having a common first central axis and the center area having a second central axis which axes are offset at a distance from each other
Data Source
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AI summary
Invention relates to a piston pin assembly for an internal combustion piston engine, which piston pin assembly comprises a piston pin having at its first end (14.1) and its second end (14.2) a first and a second affixing area for attaching the piston pin to a piston and be- tween the first and the second ends, at a center area (14.3), a third area for attaching the piston pin (14) to a connecting rod (14),the assembly comprises a power transmission system (102) engageable to a connecting rod(14)to receive work from rotational movement of the connecting rod in respect to a piston while installed to an engine and the engine is cranked or operated,a locking system(200)which selectively locks or unlocks the rotational movement of at least the third area (14.3) of the piston pin in respect to the piston.