What is the working principle of the crankcase ventilation system?
1 Answers
The principle of crankcase ventilation is: when the engine piston moves upward, the gas pressure inside the crankcase is negative, at which time the ventilation pipe draws air from the outside. When the piston moves downward from the top dead center, the pressure inside the crankcase changes from negative to positive, and at this point, the crankcase ventilation pipe exhausts gas to the outside. The functions of the engine crankcase ventilation system are as follows: 1. Prevent lubricating oil from deteriorating and reduce corrosion of friction components. During engine operation, some combustible mixture and exhaust gases leak into the crankcase. The leaked gasoline vapor condenses, thinning the oil, degrading its performance, and reducing lubrication effectiveness. If the exhaust gases contain water vapor and sulfur, sulfuric acid can form, causing corrosion to the components. 2. Reduce pressure and temperature to prevent overheating. The gases leaking into the crankcase increase the pressure and temperature inside, causing oil to leak and deteriorate from seals and gaskets. Ventilation helps cool, reduce pressure, and prevent leaks in the oil. 3. Reduce atmospheric pollution and recover combustible gases, which helps improve fuel economy and reduce emission pollution.
