15.10 Lubrication Systems Flashcards
What is the purpose of lubrication systems?
To distribute oil to bearing compartments and gearboxes.
What are the 2 types of lubrication sumps used?
Wet and dry sumps.
Where does a wet sump store oil?
In the engine.
Where does a dry sump store oil?
An external supply tank mounted on/near the engine.
What are the 2 classifications of lubrication systems?
Full flow.
Constant pressure.
What can be said about oil pressure in a full flow system?
It can’t be regulated.
What changes oil pressure in a full flow system?
Rotor speed and oil temp.
What drives the supply pump in a full flow system?
N2 rotor
What effect does a leakage have on oil pressure?
Decreases it.
Where is a pressure relief valve installed in a full flow system?
Between the delivery and suction side of the supply pump.
What can be said about the oil pressure of a constant pressure system?
It is regulated.
What valve does the constant pressure system have that the full flow system doesn’t?
Pressure regulating valve.
What effect do changes in oil temp have on oil pressure?
No effect.
What lubrication system is most common?
Full flow.
What are the advantages of a full flow system?
Simplicity.
No adjustments are necessary during maintenance.
What are the negatives of a full flow system?
Needs relatively high oil pressure when engine is at idle.
There’s a rise in oil temp after a power reduction.
What is the critical point of the lubrication system due to high temperatures.
Exhaust turbine bearing.
What is used to cool oil?
An oil cooler.
What is an oil tank made of?
Aluminium coated in silicone for fire resistance.
What surrounds a filler to catch oil spillage during servicing?
A scupper.
Where does a scupper drain spilt oil?
To the engine drain mast.
What is a strainer?
A filter
What is an oil pump designed to do?
To supply oil under pressure.
What are the 2 types of oil pumps?
Gear and gerotor.
How many elements can a gear oil pump have?
Only 2 elements: one for pressure oil and one for scavenging.
How many elements can a gerotor oil pump have?
1 for pressure oil and several elements for scavenging oil.
What is the benefit of a gerotor oil pump?
Capacity of elements can be controlled by varying the size of the elements.
Where is the oil pressure regulating valve located?
On the pressure side of the pump.
When is the pressure relief valve especially important?
When oil coolers are in the system.
Where are oil filters installed?
Upstream of oil nozzles.
Filters known as last chance filters.
When heat exchangers installed in the supply line what are they known as ?
Hot tank system
When heat exchangers are installed in the scavenger line, what are they known as?
Cold tank system
What are the 2 types of oil coolers?
Fuel cooled and air cooled.
What is oil scavenging?
Returning oil to the oil tank.
What does a de-arotor do?
Separates air from scavenging oil.
Air is vented overboard.
What is the purpose of a breather?
System venting.
What re the 2 types of monitoring transmitters?
Capacitance type.
Reed switching type.
What measures oil capacity in a capacitance type transmitter?
Electronic components in the upper part.
Describe a reed tube type transmitter?
A metal tube with a float and a multi switch assembly.
What is used to catch metal debris particles?
Magnetic chip detectors.
How are magnetic chip detectors checked?
Manually or electronically monitored.
How does a magnetic chip detector work?
Resistance drops when particles connect with magnets.
What is Spectrometric Oil Analysis Program (SOAP) used for?
To find out about internal wear.
What can SOAP do?
Find particles that cannot be caught by oil filters.
How is oil quantity checked?
On sight gauge or ECAM.
