CP Propeller Equipment - Martin's Marine Engineering Page

Lubricating oil system, VBThe VB propeller and stern tube have acommon lubricating oil system, fig 14.In order to prevent sea water penetrationthe system is kept under staticpressure by the gravity tank placedabove normal load water line in accordancewith the stern tube seal manufacturer’srecommendations.Because of a pumping effect in the propellerhub during pitch changes, oil iscirculated through propeller equipmentand oil tank. Non return valves in huband at pitch control rod secure that theoil flow to the hub passes the stern tubejournal bearings and further along thechromium steel journal to the bladeactuator mechanism.The return oil flows along the pitch controlrod back to the lub oil tank.The propeller hub is fitted with 2 plugsfor draining and venting during docking.The pitch control rod is lubricated withgrease where intermediate shafts arefitted.Lubricating oil system, VBSAs with the VB equipment the sterntube and hub lubrication is a commonsystem. The stern tube is therefore keptunder static oil pressure by a stern tubeoil tank placed above sea level, see fig11.All MAN B&W propeller equipment withseals of the lip ring type operates on luboil type SAE 30 – usually the same typeof lubricating oil as used in the main engineand reduction gear.Minimum level 3 mabove sea levelLAL64Stern tubeoil tankLow pressure pipeDrainVenting pipeOil tank(4 l)Aft sealingTI8.1Forward sealingNon–return valvesTAH63TAH62Circulating oilsystem forforward sterntube sealing2 03 34 01–2.0DrainFig 14: VB lubricating oil systemThis document, and more, is available for download at Martin's Marine Engineering Page - www.dieselduck.net13