Crankcase Oil Return Channels for Blow-By Separation Efficiency
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Solution Overview
Problem
Conventional internal combustion engines face challenges in effectively separating oil from blow-by gas due to low filtration efficiency and increased oil entrainment, particularly when space restrictions and geodetic height differences result in insufficient pressure loss potential, leading to potential oil entry into the intake tract and increased emissions.
Innovation Solution
The engine employs two separate oil separation devices, a full-load and a part-load oil separator, with distinct return channels that increase the geodetic height difference and pressure loss potential, ensuring oil is guided downwards into a reservoir, thereby preventing oil from entering the intake tract and enhancing filtration efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If space restrictions and small geodetic height differences are used in the engine design, then the engine compactness is improved, but the pressure loss potential decreases leading to insufficient oil separation
Solution Approach 1:
The patent divides the oil separation system into multiple independent oil separation devices (first and second oil separation devices) with separate return channels. This segmentation allows each device to be optimized for specific operating conditions while maintaining adequate pressure loss potential despite compact overall engine design.
Solution Approach 2:
The patent implements dynamic selection between different oil separation devices based on operating conditions (full-load vs. part-load). The system adaptively switches between the first oil separation device for full-load operation and the second oil separation device for part-load operation, ensuring optimal oil separation efficiency across all engine operating ranges while maintaining compact dimensions.
2Device complexity
If a single oil separation device is used, then the device complexity is reduced, but the filtration efficiency decreases and oil entrainment increases
Solution Approach 1:
The oil separation system is segmented into multiple specialized devices: a first oil separation device optimized for full-load operation and a second oil separation device optimized for part-load operation. Each device has its own dedicated return channel, creating a more complex but highly efficient multi-path system that prevents oil entrainment in the intake tract under all operating conditions.
Solution Approach 2:
Different oil separation devices are designed with locally optimized characteristics suited to their specific operating conditions. The first oil separation device has features optimized for high-flow full-load conditions, while the second device has features optimized for lower-flow part-load conditions, ensuring peak filtration efficiency in each regime without requiring a single overly complex universal design.
3Device complexity
If the oil separation devices are positioned close to the intake tract, then the engine layout is simplified, but oil can enter the intake tract increasing emissions
Solution Approach 1:
The system uses separate, dedicated return channels for each oil separation device that are spatially routed to prevent oil from entering the intake tract. The first return channel serves the first oil separation device and the second return channel serves the second oil separation device, creating isolated pathways that eliminate cross-contamination risks and prevent oil entrainment emissions regardless of device positioning.
Solution Approach 2:
The dedicated return channels act as intermediary pathways between the oil separation devices and the crankcase oil reservoir, providing controlled routes for oil return that prevent direct communication between the oil separation outlets and the intake tract. This intermediary structure ensures oil is safely guided away from the intake system under all operating conditions.
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
This design significantly increases filtration efficiency, reduces oil entrainment, and minimizes noxious emissions by effectively separating and directing oil away from the intake tract, maintaining optimal engine performance and reducing pollutant release.
Implementation Method 1
at least one inertia-based oil separator device with at least one inertia-based oil separator
Implementation Method 2
an ejector which is driven by compressed air from the charging device, generating a vacuum to drive blow-by gas
Data Source
AI summary
An internal combustion engine for a motor vehicle includes a crankcase. The crankcase has having at least two oil separation devices and having a return device. The return device has at least one first return channel that is flowable through by a first portion of the oil separated from the blow-by gas with a first of the oil separation devices, through which the first portion of the separated oil is guided from the first oil separation device into the reservoir. The return device also has at least one second return channel that is at least partially spaced apart from the first return channel and is flowable through by a second portion of the oil separated from the blow-by gas via the second oil separation device, through which second return channel the second portion of the separated oil is guided from the second oil separation device into the reservoir.