Patent ID: 8601785

Claim:
An oil supply system for supplying oil under pressure to enclosures of a gas turbine engine, the system comprising: a scavenge system in fluid communication with one or more of the enclosures to receive a used oil mixture therefrom; a main oil pump including a first stage and a second stage in serial communication with one another, the first stage including a centrifugal air/oil separator having an inlet in fluid communication with the scavenge system to receive the used oil mixture and separate oil and air contained therein, a main oil outlet located to discharge a major portion of the separated oil therethrough, an oil overflow outlet, and an air outlet in fluid communication with an air vent, the second stage including a second stage pump having an inlet in fluid communication with the main oil outlet of the centrifugal air/oil separator, and an outlet in fluid communication with the enclosures to circulate the oil thereto; and a make up system including a closed oil tank having a top inlet in fluid communication with the oil overflow outlet of the first stage of the main oil pump, the oil tank having at least one tank outlet located at a bottom thereof and in fluid communication with a make-up pump, the make up pump having an outlet in fluid communication with the scavenge system.