Emergency lubrication system

Abstract

An emergency lubrication system for a turbine engine includes a reservoircontaining a reserve quantity of lubricantand having a lubricant inletand a lubricant outlet. A lubricant supply lineand a lubricant outlet lineeach have a respective valvesfor regulating lubricant flow into and out of the reservoir. A fluid supply lineincludes a valvefor selectively establishing communication between the reserve quantity of lubricant and a source of pressurized fluid. During normal operation the lubricant outlet valve continuously releases lubricant at a normal rate to the component requiring lubrication while the lubricant inlet valve concurrently admits fresh lubricant into the reservoir. During abnormal operation, the lubricant inlet valve closes in response to abnormally low lubricant pressure outside the reservoir thereby preventing backflow of reserve lubricant out of the reservoir. The fluid inlet valve opens to admit pressurized fluid into the reservoir thus pressurizing the reserve lubricant. The lubricant outlet valve opens or cycles open and closed in response to a command from a controllerso that the pressurized fluid forces lubricant through the outletas a subnormal rate, which persists until the lubricant reserve is substantially depleted. The subnormal rate is ideally achieved by intermittently releasing lubricant from the reservoir, but may also be achieved by releasing a continuous stream of lubricant at a rate less than the normal rate of release.