M15.10 Lubrication Systems Flashcards
Wet sump engine lubrication systems store what?
The oil in the engines
In a dry sump where is the oil stored?
Uses an external supply tank mounted on the engine or near engine
The engines oil/lubrication systems can be classified as either?
Full flow system
Constant pressure system
What is a constant pressure system also called?
The regulated pressure system
In a constant pressure system what does the pressure regulating valve do?
Holds the oil pressure to given design value
Advantages of full flow system?
Used most commonly due to its simplicity
No adjustments are necessary during maintenance of the engine
Disadvantages of full flow systems?
System needs a large supply pump or a relatively high oil pressure when engines idle
Oil temperature rises after power reduction
Due to high temperatures what is a critical lubricating point?
The exhaust turbine bearing
4 subsystems of basic lubrication systems?
An oil reservoir and supply system
A scavenge system
A vent system
A monitoring system
3 subsystems of oil system?
Storage
Distribution
Indicating
An oil tank usually has a layer of what to give it sufficient fire resistance?
Silicone
2 ways to fill an oil tank?
Gravity
Pressure
An oil filler is surrounded by a what to catch spilt oil?
A scupper
Two most common oil pumps?
The gear pump (most common)
The geroter pump
Under normal operation should the oil pressure relief valve open?
No
How does an oil pressure relief valve work?
Used to relieve pressure and bypass oil back to the inlet side when the pressure exceeds maximum pee set system limit
All filters consist of what?
A filter housing
A removable cover
A filter bypass valve
Electric clogging indicators
If an oil cooler is installed in the supply line what is the system called?
The hot tank system
If the oil cooler is installed in the scavenge line what is the system called?
The cold tank system
Two main oil coolers for turbine engines?
Fuel cooled oil coolers- For most large jet engines
Air cooled oil coolers- For turboprops and apu
Main components of fuel cooled oil cooler?
The housing
The cover
The core
What is used to vent air overboard from the scavenge oil?
A breather
What does a de-aerator do?
Separates the air from the incoming scavenge oil
How long should you wait after engine shut down to access tank filler cap?
5 minutes
Two types of transmitters used for oil monitoring systems?
The capacitance type transmitter
The reed switch type transmitter
What is SOAP?
Spectrometric Oil Analysis Program
What is the SOAP process?
Can find particles in oil which are too small for a filter to catch
Samples are taken on regular intervals from the oil tank for analysis
Oil is vaporised by an electric arc so the metallic ions emit a light spectra
How do modern magnetic chip detectors work?
The detector has two magnets and the resistance between the two magnets is monitored by electronic control unit.
The resistance decreases when there is particles on the magnets
What happens to oil pressure when there are changes in oil temperature?
Has no effect
Where does the engine lubrication system distribute oil to?
The engine bearing compartments and the gear boxes
