Bearing Structure for Multi-Link Piston Crank Mechanism
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The existing multi-link-type piston crank mechanism in internal combustion engines has a rigid design due to the need for a bearing beam structure with an oil gallery, leading to a complex configuration and limited flexibility in lubricating oil supply for the control shaft.
Innovation Solution
A bearing structure that uses half-split main and control shaft bearing metals with in-block and in-cap oil passages, allowing lubricating oil to be supplied from the cylinder block's oil gallery to the crankshaft and control shaft bearing parts, eliminating the need for a control shaft bearing cap and simplifying the oil passage configuration.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a bearing beam structure with oil gallery is used to supply lubricating oil to the control shaft bearing part, then the lubrication function is achieved, but the design flexibility is reduced and the configuration becomes complicated
Solution Approach 1:
The patent divides the lubrication system into separate components: the cylinder block with its oil passages, the main bearing cap with oil holes and grooves, and the control shaft bearing cap. This segmentation eliminates the need for a complex integrated bearing beam structure with internal oil galleries, while still achieving reliable lubrication delivery to both the crankshaft and control shaft bearing parts through a simplified modular configuration
Solution Approach 2:
The main bearing cap serves multiple functions: it supports the crankshaft bearing, provides oil supply passages to the crankshaft, and simultaneously delivers lubricating oil to the control shaft bearing part through its integrated oil holes and grooves. This multi-functionality eliminates the need for separate dedicated oil supply structures, simplifying the overall configuration while maintaining reliable lubrication
2Reliability
If a control shaft bearing cap is formed in the beam structure, then the control shaft is supported, but the design flexibility is reduced
Solution Approach 1:
The patent separates the control shaft bearing cap from the main bearing beam structure, making it an independent component that can be designed and positioned flexibly. This segmentation allows the control shaft support structure to be optimized independently without being constrained by the main beam configuration, thereby maintaining design flexibility while ensuring reliable support
Solution Approach 2:
The main bearing cap acts as an intermediary structure that connects the cylinder block's oil supply system to the control shaft bearing cap. Through this intermediary, lubricating oil is delivered to the control shaft bearing part without requiring the control shaft bearing cap to be integrated into the rigid beam structure, thus preserving design flexibility while achieving reliable support and lubrication
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 design flexibility, simplifies the oil passage system, and ensures reliable lubrication of both the crankshaft and control shaft, reducing the complexity and increasing the reliability of the lubrication system.
Implementation Method 1
an oil groove which is formed to extend circumferentially and entirely in an inner periphery of the main bearing metals (41), and communicates with the first oil hole (42)
Data Source
AI summary
A crankshaft bearing part (11) has a pair of main bearing metals (41), and lubricating oil is guided from an oil gallery to an inner circumferential oil groove (43) through an in-block oil passage (33) and a first oil hole (42). Some of the lubricating oil is supplied to a control shaft bearing part (17) via a second oil hole (44) and an in-cap oil passage (34). Lubricating oil is guided from a third oil hole (46) in a pair of control shaft bearing metals (45) to an inner circumferential oil groove (47). The oil groove (43) in the crankshaft bearing part (11) functions also as an oil passage for supplying lubricating oil to the control shaft bearing part (17), thereby achieving a simple configuration.