An oil supply system and a method for operating the same to provide oil to a gas turbine engine in a variety of harsh operating conditions is provided. The oil supply system includes a main oil tank and an auxiliary oil tank which share oil through a tank sharing valve that may be closed if a depressurization event occurs in the main oil tank. The oil supply system further includes an auxiliary supply conduit and an auxiliary oil pump for providing oil to the gas turbine engine in the event of main oil tank depressurization or in negative gravity conditions where the oil within the auxiliary oil tank rises to the top of the tank and uncovers the oil pump supply.

A gas turbine engine includes a first bearing compartment and a seal assembly within the first bearing compartment that includes a rotatable seal seat, a gutter radially outward of the seal seat and fixed against rotation. The gutter includes a channel on its radially inner face. A second bearing compartment is also included. A scavenge pump is in communication with a first supply line configured to supply the first bearing compartment and a second supply line configured to supply the second bearing compartment. The gutter is in communication with the scavenge pump through a gutter scavenge line.

A gas turbine engine includes a first bearing compartment and a seal assembly within the first bearing compartment that includes a rotatable seal seat, a gutter radially outward of the seal seat and fixed against rotation. The gutter includes a channel on its radially inner face. A second bearing compartment is also included. A scavenge pump is in communication with a first supply line configured to supply the first bearing compartment and a second supply line configured to supply the second bearing compartment. The gutter is in communication with the scavenge pump through a gutter scavenge line. A valve between the scavenge pump and the second supply line is configured to close in response to a dry port event, such that closing the valve stops oil supply to the second supply line, while allowing oil supply to the first supply line.

An oil supply system and a method for operating the same to provide oil to a gas turbine engine in a variety of harsh operating conditions is provided. The oil supply system includes a main oil tank and an auxiliary oil tank which share oil through a tank sharing valve that may be closed if a depressurization event occurs in the main oil tank. The oil supply system further includes an auxiliary supply conduit and an auxiliary oil pump for providing oil to the gas turbine engine in the event of main oil tank depressurization or in negative gravity conditions where the oil within the auxiliary oil tank rises to the top of the tank and uncovers the oil pump supply.

A gas turbine engine includes a first bearing compartment and a seal assembly within the first bearing compartment that includes a rotatable seal seat, a gutter radially outward of the seal seat and fixed against rotation. The gutter includes a channel on its radially inner face. A second bearing compartment is also included. A scavenge pump is in communication with a first supply line configured to supply the first bearing compartment and a second supply line configured to supply the second bearing compartment. The gutter is in communication with the scavenge pump through a gutter scavenge line. A valve between the scavenge pump and the second supply line is configured to close in response to a dry port event, such that closing the valve stops oil supply to the second supply line, while allowing oil supply to the first supply line.

Aspects of the disclosure are directed to a system comprising: a tank that stores a fluid, and a conduit that includes a first end and a second end, where the conduit is configured to convey at least a portion of the fluid stored in the tank from the second end of the conduit to the first end of the conduit, where a first end region of the conduit coinciding with the second end of the conduit has a first end region density and the fluid has a fluid density, where the first end region density is greater than or equal to the fluid density such that the first end region of the conduit remains immersed in the fluid stored in the tank when the fluid in the tank is under negative gravity conditions.

A method of supplying a bearing compartment with fluid includes the steps of pumping a fluid from a main reservoir to a bearing compartment through a main supply passage which includes one or more passage segments. During a positive gravity condition, the pumping step is performed using a main pump arranged in the main supply passage. The main reservoir includes upper and lower portions. The main supply passage is in fluid communication with the lower portion. Fluid is provided from the main reservoir to the bearing compartment through a secondary supply passage that is fluidly connected to at least one segment of the main supply passage in response to a negative gravity condition. The secondary supply passage is in fluid communication with the upper portion.

Aspects of the disclosure are directed to a system comprising: a tank that stores a fluid, and a conduit that includes a first end and a second end, where the conduit is configured to convey at least a portion of the fluid stored in the tank from the second end of the conduit to the first end of the conduit, where a first end region of the conduit coinciding with the second end of the conduit has a first end region density and the fluid has a fluid density, where the first end region density is greater than or equal to the fluid density such that the first end region of the conduit remains immersed in the fluid stored in the tank when the fluid in the tank is under negative gravity conditions.

A lubrication system of a gas turbine engine includes a lubricant reservoir with a housing having a volume of oil located therein. A reservoir passage extends through the housing. One or more side passages extend from the reservoir passage and are configured to selectably fill or drain the volume of oil. An output passage is separate and distinct from the reservoir passage, and a separator wall extends into the interior of the housing from the first housing wall toward the second housing wall and between the reservoir passage and the output passage. When the lubricant reservoir is in a first orientation, the lubricant reservoir is filled via oil flowed through the reservoir passage from the first housing end, and when operated in a negative G orientation, the lubricant reservoir is drained via oil flowed through the reservoir passage and out of the second housing end.