Inverted Non-Return Valve for Crankcase Oil Separation
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Solution Overview
Problem
Conventional non-return valves in combustion engine crankcase ventilation systems face issues with freezing during non-operating states, complex designs, and difficulty in removal or replacement, which affects their operational reliability and maintenance.
Innovation Solution
A non-return valve design that utilizes gravity and pressure differences to maintain the valve body in an open position without preload, allowing quick transition to a closed position, and is integrated into the cylinder head cover or oil separating module for easy installation and removal, eliminating the need for additional components and simplifying maintenance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional non-return valves (umbrella-shaped or plate-shaped elastomer bodies) are used in the oil return, then they can prevent oil ingress into the cleanroom, but they run the risk to freeze in the non-operating state of the engine because the oil cannot discharge
Solution Approach 1:
The valve body is designed to be in the open position by default (inverted logic from conventional valves that are closed by default), allowing oil to discharge freely during non-operating states and preventing freezing. The valve only closes when crankcase overpressure occurs, reversing the conventional approach of being closed by default and opening only when needed.
Solution Approach 2:
The valve body geometry and positioning are optimized to provide a maximum opening diameter in the non-operating state, changing the flow parameters to maximize oil discharge capability. This ensures rapid oil evacuation and prevents the valve from freezing during engine idle periods.
2Reliability
If spring-loaded diaphragm valves are used, then they can remain open in the non-operating state, but the flexible tongue cannot be prevented from sagging due to aging or high stress, being a potential risk to the operational capability
Solution Approach 1:
The spring component is completely removed from the valve design. Instead of using a spring-loaded diaphragm, the valve body itself is designed to function as the sealing and actuating element, eliminating the flexible tongue that sags over time. This extraction of the spring mechanism removes the source of instability while maintaining the open-position functionality.
Solution Approach 2:
The valve body serves multiple functions simultaneously: it acts as the sealing element, the actuating mechanism, and the flow control component. The valve utilizes the pressure difference and gravity itself to open and close, without requiring external springs or actuators, making the system self-sufficient and more stable over time.
3Reliability
If non-return valves are designed to be closed in the non-operating state, then they can prevent oil ingress, but they do not provide the maximum opening diameter, being detrimental to the freezing behavior
Solution Approach 1:
The valve is designed with inverted logic: open by default in the non-operating state and closes only when crankcase overpressure occurs. This inversion ensures maximum opening diameter is available during idle periods for optimal oil discharge, preventing freezing while maintaining reliability during operation.
4Measurement precision
If pilot-operated controlled non-return valves are used, then they can be precisely controlled, but the realization is very complex
Solution Approach 1:
The valve body itself performs the sealing and actuating functions without requiring external pilots, magnets, or complex control systems. The valve automatically responds to pressure differences and gravity, achieving precise control through its own geometry and physical principles rather than external control mechanisms.
Solution Approach 2:
All external control mechanisms (pilot lines, magnetic actuators, electronic controls) are removed from the system. The valve is reduced to its essential function of responding to pressure and gravity, dramatically simplifying the overall system while maintaining effective control.
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 ensures reliable prevention of oil ingress into the cleanroom, reduces the risk of freezing, and facilitates easy installation and replacement, enhancing operational reliability and maintenance efficiency.
Implementation Method 1
in the non-operating state of the combustion engine the valve body being subject to gravity is maintained in the open position without preload
Implementation Method 2
configured to automatically move to the closed position in case of an overpressure at the crankcase side with respect to the oil separator chamber
Data Source
AI summary
An oil separating module for an internal combustion engine, including: an oil separator, an oil return arranged such that separated oil can flow through the oil return to an oil sump, a mounting, and a non-return valve having: a valve housing having a throughbore with a first end opening and a second end opening, and a valve body movably mounted in the valve housing such that the valve body transitions between an open position and a closed position. When the first end opening is above the second end opening, the valve body automatically transitions to, or remains in, the closed position when a second end opening pressure is greater than a first end opening pressure by at least a threshold pressure difference, and the valve body automatically transitions to, or remains in, the open position when the second pressure is not greater than the first pressure by at least the threshold pressure difference.