M15.10 Lubrication Systems Flashcards
Basic oil sub systems
- Reservoir and supply
- Scavenge
- Vent
- Monitoring
Where is the supply filter located in regards to the supply pump
Downstream
What are oil seals
Inner seals preventing oil escaping from the cavities
What are air seals
Outer seals that minimise the air escaping from the cavities
What is the carbon ring in the bearing compartment
A static ring of carbon which rubs against the seal seat
What is the seal seat
A rotating collar on the engine shaft
What is used to maintain contact between the seal seat and the carbon ring
Springs
Why is the bearing compartment referred to as a dry sump
The scavenge pumps remove oil faster than it’s injected
Where is the oil cooler installed in regards to the filter
Downstream
How does the vent system supply air from the FWD bearing compartment to the gearboxes
Via the radial drive shaft housing
Oil system monitoring sensors
- Quantity
- Pressure
- Temperature
- Low oil px
- Filter clogging
How is contamination checked in the oil system
Inspection of filter and MCD
Simplest type of oil supply system
Full flow
Which system has no way of regulating oil pressure
Full flow
What changes oil pressure in a fully flow system
- N2 speed
- Oil temp
- Total flow area
Difference between full flow and constant pressure system
Constant pressure has a pressure regulating valve
Disadvantages of full flow
Large supply pump or high pressure
Rise in oil temp after power reduction
Oil tank supply lines and their locations
- Pump supply - bottom
- Scavenge oil line - top
- Vent line - top
Anti - siphon device purpose
Prevents oil from flowing through the supply line to the lowest point in the system
What could happen if there was no anti siphon device in the supply line
All the oil could be transferred to the accessory gearbox
Purpose of de-aerator and its location
At the inlet for the scavenge oil line
Remove air from scavenge line
How long is the higher air pressure in the tank after engine shutdown
5 minutes
What surrounds the oil filler, that catches the spilled oil and drain to the engine mast
Scupper
Are positive or negative displacement pumps used
Positive displacement pumps
Types of pumps used
- Gear pumps
- Gerotor pumps
- Vane pumps
Filter parts
- Filter housing
- Removable cover
- Filter bypass
- Electric clogging indicators
Where is a filter with a paper medium not normally used
Scavenge filters
What type of filter is always a disposable cartridge
Paper
If the heat exchanger is installed in the supply line what is the system called
Hot tank system
What defines a cold tank system
Heat exchanger installed in the scavenge line
Main types of heat exchanger
- Fuel cooled heat exchangers
Where are air cooled heat exchangers normally used
Turboprop and APU
Oil quantity transmitter types
- Capacitance
- Reed Switch
Two main types of pressure sensors
- Bourdon Tube type
- Strain gauge type
Two main types of temperature sensors
- Thermocouple
- Thermister
SOAP
Spectrometric Oil Analysis Program
What size of particles can SOAP detect
0.001mm to 0.02mm
When should engine oil quantity be checked after shutdown with out a anti-siphon
5 to 20 mins
Why is a oil overfill dangerous
Large mounts of oil can be pumped through the vent line into the FWD bearing compartment or the de-oiler
Which seals must be replaced on a magnetic chip detector
O-rings
