Crankcase ventilation system

Abstract

A closed crankcase ventilation system for a turbocharger internal combustion engine which uses differential pressure between the turbo compressor inlet and the crankcase to force blow-by gases through a separation device. The zone of low pressure of the turbo compressor inlet is located at the innermost diameter of the compressor inlet shroud. The difference between the pressure in the compressor inlet and the crankcase creates a vacuum which pulls gas from the crankcase into the ventilation system. The ventilation system includes a high restriction separator for removing oil from the blow-by gases. A control valve bypasses the separation device when insufficient pressure differential exists to drive the separator. Additionally, a system for ventilating crankcase gases from a crankcase of the engine includes a first flow passage communicating between the crankcase and a turbocharger of the engine, an high restriction separator positioned in the flow passage for separating air contaminant mixtures from crankcase gases, a first connection for connecting a first end of the flow passage to the crankcase, a second connection for connecting a second end of the flow passage to a predetermined point of the turbocharger, a second flow passage communicating between the first flow passage and an intake manifold of the engine, and a bypass flow passage for bypassing the separator. In this case, the crankcase gases are directed through the separator during heavy load, light load and idle operating conditions when sufficient vacuum exists to draw the crankcase gases through the coalescing filter and through the bypass flow passage when a sufficient vacuum is not present.