A lubrication system for a gas turbine engine, the system comprising: a gearbox, the gearbox comprising a sump; an oil tank; a primary gearbox lubrication system configured to pump oil from the oil tank to lubricate the gearbox with a gearbox primary feed; a secondary gearbox lubrication system, configured to lubricate the gearbox with oil from the sump when the oil level in the sump reaches a predetermined level; wherein the system is configured to increase the oil level in the sump to at least the predetermined level in response to a failure of the primary gearbox lubrication system.

Various implementations described herein are directed to a lubrication system for a gearbox of an aircraft. A lubrication line is coupled to a plurality of jets and/or orifices to provide lubrication to one or more components of the gearbox. A check valve is placed within the lubrication line in a location upstream from the plurality of jets and/or orifices.

A method for monitoring a fluid system for lubricating a mechanical system. The fluid system comprises a spraying circuit connected to a main fluid circuit and to a back-up fluid circuit. The back-up fluid circuit comprises a back-up check valve closed in a nominal operating mode. The method comprises a monitoring phase comprising the generation of a first alert in the presence of the detection of a malfunction making the main fluid circuit inoperative and the back-up check valve in an open state and the generation of a second alert different from the first alert in the presence a malfunction and the back-up check valve in a closed state.

A lubrication system for a transmission includes a flow-metering device and a controller. The controller is operatively associated with the flow-metering device to cause the flow-metering device to intermittently issue lubricant from the flow-metering device into a transmission based on an operating parameter of the transmission.

A gear assembly of an aircraft including an engine is generally provided. The gear assembly includes a first gear meshed with a second gear to define a gear mesh, and a walled lubricant tank defining a lubricant reservoir and a reservoir inlet opening. The reservoir inlet opening is defined adjacent to an out-of-mesh side of the gear mesh. At least a portion of lubricant from the gear mesh enters the lubricant reservoir through the reservoir inlet opening.

A gas turbine engine for an aircraft including a unit supplied with oil from a first oil circuit and a second oil circuit. The first oil circuit and the second oil circuit each are fluidly coupled with at least one inlet and with at least one outlet of the unit and with at least one inlet and with at least one outlet of an oil tank. The first oil circuit and the second oil circuit are configured to receive oil from the oil tank and to direct the received oil to the unit. The oil tank is incorporating offset outlets to each of the oil circuits. The offset outlet of the second oil circuit is positioned higher in the oil tank than the offset outlet of the first oil circuit.

A mechanical system comprising a sump and at least one component to be lubricated or cooled arranged in the sump, the mechanical system comprising a lubricating fluid system provided with a lubricating fluid and a tank arranged in the sump. The tank is a leaking tank and is situated above said at least one component to be lubricated or cooled, the lubricating fluid flowing out of the tank by force of gravity, so as to reach said at least one component to be lubricated or cooled. The lubricating fluid system has at least one lift flow generator connected by at least one filling line to the tank and to at least one suction point present in a bottom of the sump. The lift flow generator fills the tank with the lubricating fluid present in said bottom at least during a starting phase.

A planetary gearbox of a gas turbine engine has a planet gear which, via a bearing, is arranged rotatably on a planet pin of a rotatable planet carrier. Oil is introduced through an opening, arranged radially within the bearing, into an oil feed which is open at a feed side and which is connected to the bearing and rotationally joined to the carrier. As the carrier rotates, the oil downstream of the opening is conducted toward the bearing unit by centrifugal force. The open oil feed is, between the opening and the bearing, configured an oil filter through which the oil is conducted. The filter extends counter to the flow direction of the oil from the opening in the direction of the bearing unit, in a flow direction of the oil in the open oil feed.

Embodiments are directed to solid lubricant assemblies for providing over temperature protection for bearings and gears in rotorcraft systems. A solid lubricant enters a fluid state above a certain temperature and is positioned so that fluid lubricant is applied to the bearings or gears.

A lubrication device for a helicopter including: an oil sump in which oil for lubrication is retained; a lubrication pump configured to suck the oil from the oil sump to discharge the oil; and a lubrication passage extending from the lubrication pump to a first lubrication target. The lubrication passage includes: a first supply port that supplies the oil to the first lubrication target; an oil reservoir provided upstream of the first supply port; and an opening provided upstream of the oil reservoir and above the oil reservoir. The first supply port is formed right above the first lubrication target.