Turbine Engine Lubricaion Systems Flashcards
Describe the basic principles of operation of typical turbine engine lubrication systems
Lubricates, cools and cleans engine components. Modern engines have self contained circulatory lubrication systems.
where oil is redistributed through pumps directly to the gear boxed and then sent back to the tanks by scavenger pumps. Also sealing and corrosion reduction.
Describe the function and principles of operation of the following turbine engine lubrication system component - oil cooler
The oil cooler is used to dissipate the heat passed into the oil from all the moving parts that the oil has passed over to cool them. This is done by incorporating an oil/fuel heat exchanger.
Describe the function and principles of operation of the following turbine engine lubrication system component: oil-fuel heat exchangers
Pass fuel through tubes and direct the oil over these tubes allowing heat to pass from the oil and into the fuel.
The oil is always maintained at a higher pressure to prevent fuel leaking into the oil system in the event of an internal failure of the oil-fuel exchanger.
Describe the function and principles of operation of the following turbine engine lubrication system component oil: filters/screens (coarse and fine and scavenge)
coarse strainers are fitted between the oil tank and inlet of pressure pumps to prevent debris from damaging pressure pumps.
A Fine pressure filter is fitted at the pump outlet which retains any small particles which could block the oil feed jets.
Scavenge filters are fitted in each oil return line to collect debris from the lubricated components.
Describe the function and principles of operation of the following turbine engine lubrication system component oil-
system chip detectors and magnetic plugs
Chip detector - permanent magnets inserted into the oil flow on the scavenge side of the lubrication system, to collect Ferris debris metals from each bearing chamber.
When enough ferrous metal accumulates it connects the two electrodes which allow current to flow, setting off a warning light in the cockpit to warn pilot.
Magnetic Plugs - to stop the circulation of that debris that may otherwise cause damage, and
when analysed by engineers, the type of metal on the chip detector provides information on where the disintegration of materials is happening.
Describe the function and principles of operation of the following turbine engine lubrication system component
valves (bypass and check relief)
Bypass - prevent high oil pressure from damaging oil cooler and filter. These open at high pressures to alleviate pressure build up and protect components.
Check valve - one way valves installed in some lubrication system, generally dry. Their purpose is to prevent oil from draining through the various components of the engine down towards lower part of engine.
State the reason most turbine engines use fuel to cool the oil in preference to air.
Because the fuel needs warming and so instead of designing a separate fuel heater/ oil cooling system efficient design has the oil heat the fuel and the fuel cool the oil.
