A lubrication system is disclosed. In various embodiments, the lubrication system includes a storage tank configured to store a lubricant; a flow management valve configured to direct the lubricant to a starvation tolerant component and to a valve exit conduit; and a main pump configured to receive the lubricant from the storage tank and to pump the lubricant to the flow management valve and to a starvation intolerant component.

An aircraft engine having an oil circuit and a transmission that can be supplied with oil via the oil circuit. Oil fed to the transmission can be directed out of the transmission into an oil reservoir, from which oil can be introduced directly back into the transmission via a hydraulic line path. According to the invention, the oil fed to the oil reservoir can only be fed to the hydraulic line path below a defined filling level of the oil reservoir. When the defined filling level of the oil reservoir is reached, oil can also be introduced into a further hydraulic line path.

A lubrication system for use with a gas turbine engine includes a first reservoir for containing a lubricant. The first reservoir includes a first discharge passage through which the lubricant is flowable in a first direction. A second reservoir contains the lubricant. The second reservoir includes a second discharge passage through which the lubricant is flowable in a second direction. The first direction is generally opposite to the second direction. A first pump pumps the lubricant from the first reservoir. A second pump pumps the lubricant from the second reservoir. A manifold distributes the lubricant to a component. The lubricant from the first pump and the second pump flows into the manifold and exits the manifold through a manifold discharge.

A lubrication system is disclosed. In various embodiments, the lubrication system includes a storage tank configured to store a lubricant; a flow management valve configured to direct the lubricant to a starvation tolerant component and to a valve exit conduit; and a main pump configured to receive the lubricant from the storage tank and to pump the lubricant to the flow management valve and to a starvation intolerant component.

A two-tier lubrication system may comprise an oil nozzle located in a bearing compartment. A main oil system may be configured to provide oil to the oil nozzle. A scavenge system may be configured to collect oil from the bearing compartment. A valve may be fluidly coupled between the main oil system and the scavenge system. The valve may be configured to actuate between a main flow position and a scavenge flow position.

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.

A lubrication system for a gear system of a geared turbofan engine, the lubrication system includes an upper strut including an upper sump. A lower strut includes a lower sump. The upper strut and the lower strut support a gear system. A conduit extends from the upper sump within the upper strut to the lower sump within the lower strut. A lubricant collector receives lubricant exhausted from the gear system and directing the received lubricant into one of the lower sump and the upper sump. A pump in communication with the conduit for drawing lubricant from at least one of the lower sump and the upper sump and communicates lubricant to a lubricant inlet of the gear system. The pump draws lubricant from the lower sump when operating within a positive g-force environment and draws lubricant from the upper sump when operating within a negative g-force environment. A geared turbofan engine is also disclosed.

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 disclosed lubrication system for a turbofan engine includes a pump for driving lubricant through a lubrication circuit, at least one sensor generating a signal indicative of an engine operating condition and at least one valve for controlling a flow of lubricant through the lubrication circuit. A controller controls operation of the valve to vary the flow of lubricant based on the engine operating condition to maintain lubricant flow within predefined operating limits.

A disclosed lubrication system for a turbofan engine includes a pump for driving lubricant through a lubrication circuit, at least one sensor generating a signal indicative of an engine operating condition and at least one valve for controlling a flow of lubricant through the lubrication circuit. A controller controls operation of the valve to vary the flow of lubricant based on the engine operating condition to maintain lubricant flow within predefined operating limits.