AGK Engines - Gas Turbine Bearings and Lubrication Flashcards
What type of oil system do Gas Turbines have?
Dry sump
Gas Turbine oil characteristics…
Low viscosity, synthetic oil
What allow spool shafts to rotate?
Bearings
Support loads and allow rotation to take place
Bearing characteristics…
Bearings are a low friction method to allow rotation but require lubrication to reduce friction and heat/wear
Lubrication provides high pressure oil top each bearing
Types of Bearings
Tapered Roller Bearing - allow axial and radial loads to be absorbed
Ball Bearings - Absorb radial loads ad weight bearing
In a Spool Bearing Housing, to avoid oil leak what must be higher, Air pressure or Oil Pressure?
Air Pressure
Where is the lubrication system located?
Self contained system solely located on the Gas Turbine Engine
What two main functions does the lubriction system provide?
Reduce friction and wear between moving parts (bearings)
Act as a cooling system and drawing heat away from critical components and transporting it to the cooler
What does the dry sump system incorporate?
Oil Pressure Pump
Scavenge Pump
Oil Reservoir
Oil Cooler/Fuel Heater
Filters
Magnetic Chip Detector
Air/Oil Separator or Centrifugal Breather
Which is higher, oil pressure or fuel pressure?
Oil Pressure
What happens when bleed air and pressurised oil is in one location?
Creates a mist spray where it can be exhausted into the atmosphere via an engine breather
~Causing oil loss
What is used to control and prevent oil loss?
Air / Oil Separators
What do Air/Oil Separators do?
Shortly after start, pressure should…
Rise, within 30 seconds
What ma low/high pressure indicate on start up?
Oil leak
