Two-stage filtration assembly for a diesel engine crankcase ventilation system

摘要

A two-stage filtration assembly for a diesel engine crankcase ventilation system which prevents splash oil from entering into the oil separator and limits oil mist contamination of crankcase air prior to passing into the exhaust port. A first stage filtration assembly (122) includes a first stage filter (132) featuring a wire mesh filtration media contained by a cylindrical tube (134) with perforated (expanded) steel end caps for removing and draining large oil particles and any oil splashing adjacent to the crankcase. A second stage filtration (124) assembly includes a second stage filter (150) featuring a web filtration media, preferably fiberglass, for removing small, air borne oil particles with a high efficiency during the second phase of filtration. The second stage filter (150) is mounted on an acute angle ( alpha ) to allow drainage via gravity to the first stage filter. A passageway (146) in the first stage filtration (122) assembly allows oil to drain from the second stage filter back to the crankcase. The drains prevent oil re-entrainment into the air stream, allowing maximum effectiveness of the filtration elements. <IMAGE>