Camshaft Thrust Lubrication via Crankcase Pressure
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Solution Overview
Problem
The existing camshaft lubrication systems in internal combustion engines require a significant oil pump capacity and specialized drilled passages to lubricate camshaft thrust faces, leading to increased power consumption and costs.
Innovation Solution
A camshaft system with a combination lubricant reservoir and thrust reactor in the cylinder head, utilizing a control valve to supply lubricating oil at crankcase pressure to the camshaft phaser and thrust surfaces, eliminating the need for additional oil pump capacity and drilled passages.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If drilled passages are provided in opposing sides of the structures to lubricate camshaft thrust surfaces, then lubrication is furnished to camshaft thrust faces, but the oil pump must be sized for significant leakage path requiring greater capacity and more power absorption
Solution Approach 1:
The invention extracts the lubrication function from the main oil pump system by utilizing crankcase pressure and a dedicated lubricant reservoir. The lubricant is delivered through a separate lubricating line controlled by a valve, eliminating the need for the oil pump to provide high-pressure lubrication to camshaft thrust surfaces. This separation allows the oil pump to be smaller and consume less power while still ensuring reliable lubrication.
Solution Approach 2:
The invention introduces an intermediary lubricant reservoir and valve system between the crankcase and the camshaft thrust surfaces. Crankcase pressure serves as the intermediary power source to deliver lubricant through the valve and lubricating line, eliminating the need for the oil pump to directly supply high-pressure lubrication. This intermediary system enables reliable lubrication with reduced pump capacity requirements.
2Reliability
If drilled passages are provided in opposing sides of the structures to lubricate camshaft thrust surfaces, then lubrication is furnished to camshaft thrust faces, but specialized passages must be provided in cylinder head increasing device complexity
Solution Approach 1:
The invention extracts the lubrication delivery system from the cylinder head structure by using a separate lubricating line and valve assembly. Instead of drilling passages through the cylinder head, the lubricant is delivered through an external valve and line system that connects to the camshaft phaser. This eliminates the need for specialized drilled passages in the cylinder head, reducing structural complexity while maintaining reliable lubrication.
Solution Approach 2:
The invention introduces an intermediary valve and lubricating line system that mediates between the crankcase and the camshaft thrust surfaces. This intermediary system eliminates the need for direct integration of lubrication passages into the cylinder head structure. The valve assembly acts as an intermediary component that controls lubricant flow without requiring modifications to the cylinder head geometry.
3Reliability
If oil pump capacity is increased to provide lubrication for camshaft thrust surfaces, then lubrication is furnished, but the pump absorbs more power
Solution Approach 1:
The invention extracts the high-pressure lubrication function from the oil pump system by utilizing crankcase pressure and a dedicated valve-controlled lubricating line. The oil pump is no longer required to deliver high-pressure lubrication to camshaft thrust surfaces, allowing it to be sized for lower power consumption while still ensuring reliable lubrication through the alternative crankcase pressure-driven system.
Solution Approach 2:
The invention changes the pressure parameter for lubrication delivery from high pump pressure to lower crankcase pressure. By utilizing the existing crankcase pressure environment and a valve-controlled line, the system achieves reliable lubrication without requiring the oil pump to operate at high pressure. This parameter change allows the pump to be smaller and consume less power.
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 reduces the oil pump capacity requirements and allows for efficient lubrication of both camshaft thrust surfaces using a single control valve, maximizing oil pressure for phaser operation while minimizing power absorption.
Implementation Method 1
The control valve furnishes lubricating oil under pressure to the camshaft phaser
Implementation Method 2
lubricating oil leaves the control valve and entering the lubricant reservoir and thrust reactor at crankcase pressure
Implementation Method 3
lubricating oil serving the dual function of not only operating camshaft phaser, but also providing lubrication for a portion of the camshaft
Data Source
AI summary
A camshaft system for internal combustion engine includes a camshaft having a thrust ring which is lubricated by oil from a control valve which operates a camshaft phaser with lubricating oil, and with the lubricating oil being furnished to the camshaft at crankcase pressure after the oil leaves the camshaft phaser.