Patent ID: 7870850

Claim:
A crankcase ventilation system for an internal combustion engine generating blowby gas in a crankcase containing engine oil and oil aerosol, said system comprising an air/oil separator having an inlet receiving blowby gas and oil aerosol from said crankcase, and having an air outlet discharging clean blowby gas, and an oil outlet discharging scavenged separated oil, and a jet pump pumping said scavenged separated oil from said oil outlet of said separator to said crankcase, wherein said separator has a pressure drop thereacross such that the pressure at said inlet and in said crankcase is higher than the pressure at said air outlet and at said oil outlet, the pressure differential between said crankcase and said oil outlet normally tending to cause backflow of oil from the higher pressure crankcase to the lower pressure oil outlet, said jet pump supplying pumping pressure greater than said pressure differential to overcome said backflow tendency and instead cause suctioning of scavenged separated oil from said oil outlet and pumping same to said crankcase, said jet pump is an air-driven jet pump having a pressurized drive input receiving pressurized motive air from a compressed air source, a suction input receiving separated oil from said oil outlet of said separator, and an output delivering jet-pumped oil and motive air to said crankcase.