Jet Engine Lube System

A look at the components of a typical jet engine lube system, and a simplified explanation of how they all work together. We use examples of each component from several different engines, and we go through some hand-made diagrams...

Piston engines need lubrication for the sliding of piston rings against cylinder walls, and lubrication of journal bearings. The oil also is used as a coolant, sometimes even sprayed on the undersides of pistons.

Turbine engines use high temperature tolerant oil to cool the roller bearings supporting the main rotor. The oil is also used as a lubricant for the accessory drive gearboxes.

Piston engine oil is higher in viscosity, and turbine engine oil is higher in temperature tolerance.

Engine oil has 5 functions:

1 - Lubrication
2 - Cooling
3 - Carrying away contaminants and wear debris
4 - Power transmission
5 - Corrosion prevention

#4 may seem odd. Think hydraulic valve lifters and cam phasers in piston engines. In Turbine engines, think vsv actuators and torque meters.

The functions are prioritized differently:
Piston engines 1 2 4 3 5
Turbine engines 2 3 1 4 5

That's my comparison.