Lubrication Flashcards
What are the functions of lubricating oil in reciprocating engines
To reduce friction between moving parts and remove heat
Name two important characteristics of aircraft engine oil
Oil must be light enough to circulate freely but heavy enough to provide the proper oil film at engine operating temperatures
What could happen to an oil that is too low in viscosity at normal engine operating temperatures
becomes thin and the oil film between moving parts is easily broken, resulting in premature wear
What are some of the factors that must be considered by an engine manufacturer in determining the proper grade of oil for particular engine
Operating load and temperature as well as the rotational speed
Why do aircraft reciprocating engines use a relatively high viscosity oil
large operating clearance and operate at high temperatures and pressure
Name some oil contaminants
Metal particles, dirt, carbon, moisture and acids
What is possible indication of low oil pressure together with high oil temperature
A low oil supply
Why do oil reservoirs have expansion space
To provide for oil foaming, thermal expansion, and air in the return oil
What could cause oil foaming
Diluted oil, contaminated oil, and the oil level is too high
What controls oil pressure in a gear type oil pressure pump
Oil pressure relief valve
What function does an oil cooler bypass valve perform
It directs the oil either through the cooler or around it in order to maintain proper operating oil temperatures
What could be a possible indication if the oil cooler passage becomes obstructed
A high oil temperature
Where is the oil temperature bulb usually located
At the engine oil inlet
What type of oil is used in a turbine engine oil system
Synthetic oil
Where is the most critical point of lubrication in a gas turbine engine
At the turbine bearing
