CP Propeller Equipment - Martin's Marine Engineering Page

2 03 25 73–1.0Blade footIntermediate flangeSlide ringO–ringFig 7: Blade sealing ringsOil distributionThe oil distribution to the hydraulicservo motor can be carried out in twodifferent ways. For two–stroke plantsthe oil distributor is located at the shaftline.For four–stroke plants with reductiongearboxes the oil distributor caneither be placed at the front end of thegearbox or in the shaftline.Shaft mounted OD–ringThe shaft mounted unit consists of acoupling flange with OD–ring and pitchfeed–back. Via the oil distribution ring,high pressure oil is connected to oneside of the servo piston and the otherside to the drain.The piston is herebymoved setting the desired propellerpitch. A feed–back ring is connected tothe hydraulic pipe by slots in the couplingflange, fig 8. The feed–back ringactuates a displacement transmitter inthe electrical pitch feed–back boxwhich measures the actual pitch.The inner surface of the oil distributionring is lined with white–metal.The ringitself is split for exchange without withdrawalof the shaft or dismounting of thehydraulic coupling flange.The sealing consists of mechanicalthrow–off rings which ensures that nowear takes place and that sealing ringsof V–lip–ring type or similar are unnecessary.The oil distributor ring is prevented fromrotating by a securing device comprisinga steel ball located in the ring. Acceptableinstallation tolerances are ensuredand movement of the propellershaft remains possible.In the event of failing oil pressure orfault in the remote control system,special studs can be screwed into theoil distribution ring hereby making manualoil flow control possible. A hold circuitwill then maintain the chosen pitch.Gearbox mounted OD–boxFor propulsion plants with reductiongearboxes the propeller equipment canbe supplied with an oil distribution boxmounted at the front–end of the gearbox.The OD–box incorporates an electricpitch feed–back.Electrical pitch feed–backbox2 04 07 48–7.1Propeller shaftHydraulic pipeFig 8: Coupling flange with OD–ring and pitch feed–back ringOil distribution ring(OD–ring)Feed–back ringThis document, and more, is available for download at Martin's Marine Engineering Page - www.dieselduck.net9