Safety shut-off valve for crankcase emission control system

Abstract

A closed crankcase emission control system for an internal combustion engine includes a replaceable filter element having a ring of filter media; a first end cap at one end of the media ring; a sump container defined by a second end cap at the other end of the media ring and a cup-shaped valve pan fixed to the second end cap; and a check valve in the valve pan to block blow-by gas flow directly into the filter element during engine operation, and to allow collected oil to flow out of the sump container during engine idle or shut-down. A shut off valve is provided to prevent oil from passing through the emission control system to the engine. The shut off valve comprises a cylindrical float member with a supporting body and a seal, where the body includes a guide member. The float member could also be a ball valve. The float member floats with the level of oil in the housing, and can fluidly seal against a valve seat to prevent oil passing to the engine. The shut off valve can be incorporated into the filter element, into a central support tube of the housing, or into the inlet or outlet fittings for the housing. Supporting structure is provided to maintain the float member in a proper orientation. A pressure relief valve can also be provided upstream from the shut-off valve to relieve system pressure when the shut-off valve is closed.