Cummins Engine Company, Inc.

Fleetguard, Inc.

John M Partridge

David M Ruch

Peter K Herman

Glenn L Baker

Alan S Bounnakhom

Donald W Beach

J Eric Parlow

Brett Herrick

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.

Crankcase ventilation system

A closed crankcase ventilation system which relies on a vacuum assist from the turbocharger inlet to suction blow-by gases from the crankcase. The system includes a coalescer/filter which is operative to filter any oil particles which may be entrained in the blow-by gases before they are released into the turbocharger inlet. A pop off valve is also included in order to prevent the engine crankcase from becoming over pressurized as a result of back pressure caused by either a plugged coalescer/filter or some catastrophic engine malfunction. Further included is a vacuum limiting valve which prohibits the vacuum assist produced by the air inlet to the turbocharger from producing too low of an absolute pressure, thereby preventing an imbalance in pressure across the seals of the turbocharger. The system further includes a bypass valve which also prevents the crankcase from becoming over pressurized by routing the flow of blow-by gases around the coalescer/filter if the pressure in the crankcase becomes too great. Finally, the present invention incorporates a single mounting head which allows the various valves and filters of the present invention to be mounted thereon. The mounting head may then be conveniently attached to the engine at a single location.

Closed crankcase ventilation system

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Columbus, IN, United States of America

John M Partridge