US Patent 10138812 Gas turbine engine bearing chamber seals

A gas turbine engine sealing air system including a bearing chamber seal to prevent lubricant fluid loss from a fluid chamber, the sealing effected by ingress of sealing air. The system includes an air vent duct coupled to the bearing chamber seal. An ejector is located within the air vent duct to pump sealing air from the bearing chamber seal and through the air vent duct. A first duct is coupled between a starter air system of the gas turbine engine and the ejector to provide motive fluid to the ejector during gas turbine engine starting.