Abstract: The invention relates to an air filter having a primary air region and a secondary air region separated by a barrier. The primary air region contains a filter element for filtering out particles in the primary air. The secondary air region is designed to receive crankcase emissions sent from an engine's crankcase. Crankcase emissions are a result of gas escaping past the piston rings and into the crankcase due to high pressures in the cylinder during compression and combustion. To aid in removing these gasses from the crankcase, a venturi is enclosed within the housing to increase the negative pressure within the housing and in the secondary air region. This increase in negative pressure draws crankcase emissions out of the crankcase and thus reduces oil and crankcase gas bleeding from the crankcase.

Abstract: A closed crankcase emission control assembly for an internal combustion engine incorporates into a single compact unit a pressure control assembly, a filter and an oil drain check valve. The pressure control assembly has a gate whereon oily contaminated crankcase emission impinge and oil is separated. The separated oil is collected in a reservoir and returned to the crankcase. The pressure control assembly also has a variable orifice agglomerator which agglomerates particles in the contaminated crankcase emission to form larger particles. Thus, the pressure control assembly simultaneously regulates pressure, separates oil and agglomerates particles. The agglomerated particles are filtered by a filter which may be coarse and clogs less often.