Aircraft Engine Lubrication Unit ( Lubrication Pump)

Lubrication unit Or simply said the Lubrication pump system is the main driving force behind the pressurized lubricants in a jet engine. Its main function is to provide oil under the required pressure for lubrication of the engine components and spool bearings, then perform the scavenging (returning) of the oil after lubrication process then finally to directs it to the oil tank via the oil/fuel heat exchanger.

In order to pressurize and to maintain positive displacement flow, it uses a series of pumps which are driven by a single shaft. Often the pump is a Gerortor pump (Click on to read on Gerotor pump construction) which is driven by a single shaft. Number of pumps in the shaft depends on the number of supply and scavenge systems available.  

Lubrication units has its main supply inlet from the Main Oil Tank , one or more Supply lines and one or more scavenge lines for returning oil. It also has various tapping for temperature and pressure measuring sensors. (See below)

The return lines are equipped with scavenge filter screens/mesh to remove any debris from entering the pump system. Each scavenge line is often provided with oil condition monitoring magnetic chip detectors. Magnetic chip detectors works by attracting metal substances to its tip and provide good indications on possible failures in the system ( based on metal analysis). It also aid in reducing  the amount of powdery metallic debris in oil system by attracting the metallic substances.(See below)