Hydrostatic Oil Return Valve Crankcase Ventilation
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Solution Overview
Problem
Existing oil return valves for crankcase ventilation systems in internal combustion engines are bulky, expensive, and inefficient in terms of installation space, with issues such as sooting in ball check valves and sensitivity to high oil temperatures and aggressive media in diaphragm valves.
Innovation Solution
A hydrostatic oil return valve design utilizing a valve cylinder and valve pipe with a siphon principle, where the pressure difference between two chambers prevents blow-by gases from entering the oil separator, and can be implemented cost-effectively with simple installation methods, including press fitting or gluing, using round rod material.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a line end including a siphon is used to prevent blow-by gas from entering the return line, then the valve function is achieved, but a relatively large amount of space inside the crankcase is required
Solution Approach 1:
The invention integrates the siphon function directly into the valve body structure. The valve core is formed with an integrated siphon channel that combines the valve seating function and the siphon liquid seal function in a single compact component, eliminating the need for separate siphon structures and reducing installation space requirements.
Solution Approach 2:
The patent merges the valve core and siphon structure into a single integrated component. The valve body incorporates both the valve seating surface and the siphon channel, combining multiple functions (valve operation and gas sealing) into one element, thereby reducing the overall space required in the crankcase.
2Reliability
If a ball check valve is used to prevent blow-by gas, then the valve function is achieved, but the ball may jam due to sooting
Solution Approach 1:
The invention removes the ball component entirely from the valve mechanism. Instead of using a ball check valve that is susceptible to sooting and jamming, the patent employs a needle valve design where the valve core is guided by a guide surface, eliminating the harmful effect of sooting on valve operation.
Solution Approach 2:
The patent replaces the ball check valve mechanical system with a needle valve system featuring a guide surface. This substitution changes the sealing mechanism from a ball-to-seat interface to a needle-to-seat interface with lateral guidance, improving reliability by preventing soot accumulation and jamming.
3Reliability
If a diaphragm valve is used to prevent blow-by gas, then the valve function is achieved, but the diaphragm is sensitive to high oil temperatures and aggressive media
Solution Approach 1:
The invention replaces the sensitive elastomer diaphragm with a more robust metal or heat-resistant material valve core. This substitution uses a material that can withstand high temperatures and aggressive oil media, eliminating the reliability issues associated with diaphragm degradation under harsh conditions.
Solution Approach 2:
The patent changes the material parameter of the valve core from elastomer (diaphragm) to a heat-resistant material capable of withstanding high oil temperatures and aggressive media. This parameter change improves the valve's ability to operate reliably in the harsh crankcase environment.
4Reliability
If a diaphragm valve is used, then the valve function is achieved, but the seat requires a high quality surface resulting in increased costs
Solution Approach 1:
The invention designs the valve core with an integrated guide surface that provides lateral guidance. This local quality feature is built into the valve core geometry itself, requiring only localized precision machining rather than a high-quality surface over the entire seating area, thereby reducing manufacturing costs.
Solution Approach 2:
The patent merges the guide surface function into the valve core structure itself. The guide surface is an integral part of the valve core geometry, combining the sealing function and guidance function in a single feature, which simplifies manufacturing and reduces the need for separate precision-machined components.
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 hydrostatic oil return valve effectively prevents blow-by gases from entering the oil separator while optimizing installation space and reducing costs, providing a compact and cost-effective solution for crankcase ventilation systems.
Implementation Method 1
The principle here is the siphon principle... the pressure difference above the liquid level of a first chamber, formed by the annular gap of bore 10 and valve pipe 2, brings about a shift in the liquid level in the siphon area
Implementation Method 2
the pressure difference above the liquid level of a first chamber... brings about a shift in the liquid level... The limiting pressure, at which a gas transfer takes place, may be easily computed using height x=x1+x2 of the liquid column
Implementation Method 3
The limiting pressure, at which a gas transfer takes place, may be easily computed using height x=x1+x2 of the liquid column in the previously described limit case
Data Source
AI summary
An oil return valve for a crankcase ventilation system of an internal combustion engine is provided that is essentially situated in the crankcase (3) and includes a valve cylinder (1) and at least one valve pipe (2).