Liquid Return System Sloped Housing Prevents Oil Ejection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing fluid return systems for internal combustion engines face challenges in preventing oil ejection into the air intake, particularly due to pressure drops and sludge buildup, which can lead to undesirable emissions and reduced engine reliability, and often require design modifications that are not compatible with mass production engines.
Innovation Solution
A liquid return system with a housing featuring a sloped bottom piece and drainage means that creates a physical height difference to prevent liquid transfer from one side to another, using a fluid passage and drainage system to direct liquids safely back to the crankcase, eliminating the risk of oil being exhausted into the intake system, and can be integrated with minimal design modifications.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If a one-way valve is used to prevent reverse oil flow, then oil ejection is reduced, but the system becomes unreliable when the valve sticks open due to sludge or improper assembly
Solution Approach 1:
The invention removes the one-way valve component entirely from the system. Instead of relying on a valve mechanism that can fail, the design uses a passive check valve formed by the geometry of the housing and drain tube, where the liquid flow itself creates the sealing action through surface tension and capillary effects, eliminating the reliability issues associated with mechanical valves.
Solution Approach 2:
The invention introduces a check valve mechanism that acts as an intermediary between the separator and the drain tube. This check valve uses the liquid's own surface tension and capillary action to prevent reverse flow, rather than using a mechanical component that can fail. The check valve is formed by the interaction between the liquid and the geometric features of the housing.
2Stress or pressure
If a siphon is used to compensate for pressure drop, then oil flow control is improved, but the risk of oil being sucked into the intake increases dramatically when pressure drop increases
Solution Approach 1:
The invention replaces the complex siphon mechanism with a simple, passive check valve structure that relies on basic physical principles (surface tension, capillary action) rather than complex geometry. This simpler structure is less prone to failure and does not require precise manufacturing tolerances.
Solution Approach 2:
The check valve acts as an intermediary that allows liquid to flow in one direction while preventing reverse flow through capillary and surface tension effects. This intermediate structure provides a reliable barrier that is not dependent on maintaining specific pressure differentials.
3Stress or pressure
If the drain is configured directly to the oil pan, then pressure drop compensation is improved, but design modifications to engine block and cylinder head are required
Solution Approach 1:
The invention designs the separator housing to integrate multiple functions: separation, liquid storage, and controlled return to crankcase. The housing itself is shaped to provide the check valve function and the drain tube geometry, eliminating the need for separate components or engine block modifications.
Solution Approach 2:
The invention combines the separator, liquid storage chamber, and return mechanism into a single integrated housing assembly. The drain tube is formed as part of the housing structure, and the check valve function is provided by the geometric relationship between the housing and drain tube, merging multiple functions into one component.
4Reliability
If liquid is stored until engine shutdown, then the impact of pressure changes is limited, but liquid may flow between dirty and clean sides by way of the liquid transfer channel
Solution Approach 1:
The invention segments the separator into distinct zones: a dirty side for receiving blow-by gas, a clean side for delivering separated gas to the intake, and a central liquid collection chamber. The check valve and drain tube geometry create physical barriers that prevent liquid from migrating between the dirty and clean sides, while still allowing controlled return to the crankcase.
Solution Approach 2:
The check valve structure acts as an intermediary barrier between the liquid collection chamber and the clean side gas outlet. The geometric features of the housing and drain tube create capillary and surface tension effects that prevent liquid from crossing into the clean side, while still allowing the desired liquid return function.
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 system effectively reduces the risk of liquid being exhausted with the gas into the engine intake, ensuring cleaner emissions and improved engine reliability without requiring significant design changes to the engine block or cylinder head.
Implementation Method 1
a sloped portion of the bottom piece at the second side of the housing is inclined along a length of the bottom piece at the second side relative to a first portion of the second-side bottom piece such that a vertex of the incline coincides with at least a portion of the fluid passage
Implementation Method 2
drainage means, and a sloped portion of the bottom piece at the second side of the housing is inclined along a length of the bottom piece at the second side relative to a first portion of the second-side bottom piece
Data Source
Figure 1A~2B
Figure 3~5B
AI summary
A liquid return system for an internal combustion engine is provided. The system includes a housing, a fluid separating means in fluid communication with a first side and a second side of the housing, and a fluid passage bounded at least in part by a bottom piece of the housing, the fluid passage being in fluid communication with both the first and second sides of the housing. The bottom piece of the first side of the housing comprises a drainage means, and a sloped portion of the bottom piece at the second side of the housing is inclined along a length of the bottom piece at the second side relative to a first portion of the second-side bottom piece such that a vertex of the incline coincides with at least a portion of the fluid passage.