64.20 Turbine Engine Lubrication Systems

64.20.2 Describe the basic principles of operation of typical turbine engine lubrication systems.

A turbine engine lubrication system provides a continuous supply of clean, cooled oil to the engine bearings, gears, and other moving components.

Its main functions are to:

• reduce friction and wear;

• carry away heat;

• protect components from corrosion; and

• help maintain smooth and reliable engine operation.

Oil Pump

The pressure pump draws oil from the oil tank and delivers it under pressure to the parts of the engine requiring lubrication.

The pump is normally driven by the engine accessory gearbox.

Oil Filter

The oil filter removes contaminants from the oil before it reaches sensitive engine components.

Most turbine engines use a full-flow filter, through which the normal oil supply passes.

A filter bypass valve may allow oil to continue flowing if the filter becomes blocked.