Maprom Propeller Shaft Systems

Water-lubricated propeller systems

Different conditions require different approaches.

• 
  1

  A-Bracket

  In an A-bracket, outboard water lubricates the bearing system, either by natural flow or by force feeding. Especially for abrasive inland river conditions we recommend the use of 60 Rc hard coated Maprom NCB shaft sleeves shrink fitted over the propeller shaft, as counter running surface for the bearings to guarantee optimal life times.

• 
  2

  Open systems

  In open systems the same bearings and shaft liners are recommended. In addition Maprom forward stern tube seals are mounted including a simple, but reliable, lubrication system. For highly abrasive river conditions we recommend maintenance free and non-clogging Maprom MK Separators.

• 
  3

  Closed systems

  Mounting both Maprom forward GS- and aft GS-seal on either end of the stern tube creates the by Maprom introduced closed water-lubricated systems. These systems have been used since the beginning of the 70-ties. In closed systems our bearings and NCB liners have achieved operational life time in excess of 245.000 running hours.

  The system, however, requires an on-board lubrication tank. In closed systems, the risk for shaft-corrosion is less. The use of constant and controlled quality fresh water for lubrication, with or without additives, enables the installation of simpler (bronze e.g.) shaft liners. Closed systems show lower total system wear and consequently longer life times of the bearings and seals than open sea or river water-lubricated systems. The main difference is the use of aft seals fitted between the propeller and the stern tube. Additionally a water quality package is installed to provide clean lubricating water to the seal and bearings.