Patent ID: 8245818

Claim:
A method for scavenging oil in a gas turbine engine comprising: separately directing a flow of used oil and a flow of exhaust air collected in a first engine bearing cavity into first and second scavenging passages, respectively; diverting an oil flow from an oil supply pump, into a first oil flow supply and a second oil flow supply; using the first oil flow supply as a driving fluid flow to drive the flow of used oil in the first scavenging passage to pass through an oil-oil ejector, and then directing the driven flow of the used oil into an oil tank; directing the second oil flow supply to an engine oil supply system and increasing the second oil flow supply in response to a backpressure increase in the engine oil supply system; and using an air/oil separator at a location upstream of the oil-oil ejector to separate oil contained in the flow of exhaust air directed in the second scavenging passage and then driving the separated oil through the oil-oil ejector into the oil tank while discharging the separated exhaust air out of the engine.