Crankcase Separator with Pressure-Actuated Shutters
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Solution Overview
Problem
Existing separator devices for internal combustion engines, particularly in-line two-cylinder engines with zero degree offset cranks and single-cylinder engines, face challenges in maintaining the engine crankcase under vacuum and achieving efficient oil drainage due to varying crankcase pressure, leading to complex liquid/gas separation and contamination issues.
Innovation Solution
A separator device with actuator-controlled inlet and drainage outlets that adjust based on piston motion, allowing gas and liquid entry during increased crankcase pressure and oil drainage during reduced pressure, utilizing a leaf shutter and T-shaped shutters to manage airflow and separation, eliminating the need for a pressure regulation valve.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional separator devices are used in in-line two-cylinder engines with zero degree offset cranks or single-cylinder engines, then the device structure is simple, but the crankcase pressure varies significantly making it impossible to maintain vacuum and achieve efficient oil drainage
Solution Approach 1:
The patent applies dynamics by making the separator device adaptive to varying crankcase pressure conditions. The actuator means (membrane and shutter system) dynamically adjust the inlet and drainage outlet openings based on real-time pressure differentials between the crankcase and separator device, enabling reliable vacuum maintenance and oil drainage in engines with significantly variable crankcase pressure
Solution Approach 2:
The separator device uses the pressure differential itself as the actuating force - when crankcase pressure exceeds separator pressure, the membrane deflects to open the inlet shutter and close the drainage outlet shutter automatically, without requiring external control systems or additional energy input
2Reliability
If pressure regulation valves (PRV) or variable cross-section nozzles (PCV) are used to maintain crankcase vacuum, then the crankcase can be kept under vacuum in three or four cylinder engines, but these valves are ineffective in in-line two-cylinder or single-cylinder engines due to significant pressure variations
Solution Approach 1:
The separator device with pressure-differential actuated shutters provides universal applicability across different engine types (single-cylinder, in-line two-cylinder with zero degree offset, three-cylinder, four-cylinder). The same device structure automatically adapts to the specific pressure characteristics of each engine type through its passive membrane-shutter mechanism, eliminating the need for engine-specific valve selection
3Productivity
If the drainage outlets remain open during piston motion that increases crankcase pressure, then oil can drain continuously, but liquid/gas separation becomes complex and contamination increases
Solution Approach 1:
The drainage outlet shutter operates periodically, opening only during the piston motion phase that creates negative pressure differential (when crankcase pressure is lower than separator pressure) and closing during the phase that creates positive pressure differential. This periodic action ensures oil drainage occurs only when separation conditions are favorable, preventing liquid contamination while maintaining drainage productivity
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
Ensures effective separation and drainage of oil, maintaining the engine crankcase under vacuum at all operating conditions, reducing contamination and achieving positive crankcase ventilation without a PRV valve, by optimizing the pressure cycle and airflow through the device.
Implementation Method 1
membrane (17) which is deflected by the pressure differential between the environment of the engine crankcase and the interior of the separator device
Implementation Method 2
two T-shaped shutters (18), each comprising a stem with a widened end and a disc-shaped head, which are respectively inserted into the two drainage outlets (6) in a sealing manner
Implementation Method 3
separator device 1 has a casing 2 defining a separation chamber 3 therein
Data Source
Figure 1~3
Figure 4~6
Figure 7~8
AI summary
A separator device for a system for recirculation of the blow-by gases of an internal combustion engine comprises a casing (2) containing a separation chamber (3) and having an inlet (4) for communication with the engine crankcase and an outlet (5) for communication with the engine intake manifold, as well as one or more drainage outlets (6) ending in the engine crankcase, for returning the liquid separated in the separation chamber (3) into the engine crankcase. Actuator means (7, 6c) sensitive to pressure in the engine crankcase are associated to the inlet (4) and to the abovementioned drainage outlets (6) so that when the pressure in the engine crankcase is higher than the pressure in the separator device, the inlet (7) is open and the drainage outlets (6) are closed, while when the pressure in the engine crankcase is lower than the pressure in the separator device, the inlet (7) is closed and the drainage outlets (6) are open.