Buoyancy-Actuated Check Valve for Engine Oil Venting

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Solution Overview

Problem

Conventional check valves in internal combustion engine ventilation systems face issues such as freezing during idle, slow oil drainage, and unintended closure due to pressure fluctuations, leading to inefficient oil return and potential contamination of the clean room.

Innovation Solution

A compact, integrated ventilation module with a check valve that remains open independently of gas pressures, using buoyancy to automatically close when a defined oil level is exceeded, ensuring continuous oil return and preventing oil from entering the clean room.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional check valves (umbrella-shaped or plate-shaped elastomer body) are used to prevent oil from entering the clean room, then oil return is blocked during operation, but the valve remains closed during idle causing freezing

Engineering Contradiction:
Improveoil return functionVSAvoidfreezing behavior during idle
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The patent changes the state parameter of the valve from pressure-actuated to buoyancy-actuated. The valve body is designed to float on oil, changing its position based on oil level rather than pressure differential. This allows the valve to remain open during idle (preventing freezing) while closing when oil level rises during operation (preventing contamination).

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The valve body serves dual functions: it acts as both the closing element and the float. The valve automatically responds to oil level changes through buoyancy without external control, making the system self-regulating and eliminating the need for external actuators or complex control mechanisms.

Inventive Principle:
Principle #25Self-service

2Ease of operation

If spring tongue valves or float body valves are used to control oil return, then oil can drain during operation, but the valve closure is not well-defined leading to functionality issues

Engineering Contradiction:
Improveoil drainage capabilityVSAvoidvalve closure definition
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The valve body is designed with a spherical or substantially spherical shape. This geometric form provides stable floating characteristics and well-defined equilibrium positions. The spherical shape ensures predictable buoyancy behavior and clear open/closed states, eliminating the indeterminate closure issues of flat or irregularly shaped valves.

Inventive Principle:
Principle #14Spheroidality (Curvature)

Solution Approach 2:

The patent transitions from spring-based or irregular float mechanisms to a spherical float that relies purely on buoyancy. This changes the controlling parameter from elastic force or irregular buoyancy to predictable Archimedes buoyancy, providing well-defined valve positions based on oil level.

Inventive Principle:
Principle #35Parameter changes

3Ease of operation

If the oil return is kept open to prevent freezing, then oil can drain continuously, but uncleaned gas enters the clean room causing contamination

Engineering Contradiction:
Improvecontinuous oil drainageVSAvoidcontamination of clean room
Core Design Contradiction:
Ease of operationVSObject-generated harmful factors

Solution Approach 1:

The spherical valve body acts as a float that provides continuous feedback on oil level. When oil level rises during operation, the float automatically rises and closes the return line. When oil level drops during idle, the float descends and opens the return line. This feedback mechanism ensures the valve responds appropriately to operating conditions without external control.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The valve transitions from a static pressure-actuated design to a dynamic buoyancy-actuated design. The spherical float continuously adjusts the valve position based on real-time oil level conditions, enabling the system to adapt to changing operational states and prevent both freezing and contamination.

Inventive Principle:
Principle #15Dynamics

4Ease of operation

If externally controlled valves (compressed air or magnetic force) are used to ensure maximum opening during idle, then oil drainage is improved, but device complexity increases significantly

Engineering Contradiction:
Improveoil drainage efficiencyVSAvoidvalve control system
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The spherical valve body serves dual functions: it acts as both the closing element and the float. The valve automatically responds to oil level changes through buoyancy without external control, making the system self-regulating and eliminating the need for external actuators or complex control mechanisms.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The patent extracts the external control systems (compressed air actuators, magnetic controllers, pumps) from the valve mechanism. By using the spherical float's natural buoyancy, all external control components are eliminated, dramatically simplifying the device while maintaining effective oil drainage and prevention of freezing.

Inventive Principle:
Principle #2Taking out (Extraction)

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 a continuous and efficient oil return under all engine operating conditions, preventing oil from entering the clean room and reducing the risk of contamination, while maintaining a compact design without the need for additional sealing components or complex external controls.

Implementation Method 1

The spherical valve body (37) is displaced upwards as a whole when oil rises in the oil return line (65) and the liquid level in the valve chamber (50) rises above a critical level and exerts a buoyant force on the valve body (37)

Methodology Applied
Scientific EffectBuoyancy: Archimedes' Principle (Buoyancy)

Implementation Method 2

The spherical valve body (37) falls back down into the open position due to gravity as soon as the oil level drops and no more liquid-related buoyancy forces act on the spherical valve body (37)

Methodology Applied
Scientific EffectGravity: Gravitation

Data Source

PatentEP2937533B1Ventilation module for a combustion engine
Publication Date: 2017.12.20 BRUSS SEALING SYST GMBH
  • EP2937533B1 patent drawingFigure 1
  • EP2937533B1 patent drawingFigure 2~3
  • EP2937533B1 patent drawingFigure 4

AI summary

A venting module (10) for an internal combustion engine comprises an oil separator (13) with an oil return line (17) and a check valve arranged in the oil return line (17). The check valve (20) comprises a valve housing (27) and a valve body (37) which is slidably held as a whole in the valve housing (27) between an open position and a closed position. When the internal combustion engine is at rest, the valve body (37) is held in the open position without preload and by gravity. During operation of the internal combustion engine, the valve body (37) is in the open position regardless of the applied gas pressure if a defined liquid level in the valve housing is not exceeded. The valve body is designed to move automatically to the closed position by buoyancy when a defined liquid level in the valve housing is exceeded.The venting module (10) has a sealing element (12) that seals the oil return (17) and is arranged under pressure between the venting module (10) and the engine when the venting module (10) is installed.