Skip to main content

Cylinder lubrication system for a crosshead engine


The cylinder lubricator pump block consists of a series of small engine driven positive displacement pumps. A rotating shaft with cams mounted on it push pivoted levers against a series of spring loaded plungers which pump cylinder oil to the lubricating quills via suction and delivery valves. The stroke of the pump ( and thus the quantity of oil delivered) is adjusted by means of a screw which moves the pivoted lever closer or further away from the driving cam. In the example shown, screwing the adjusting screw inwards would reduce the quantity of oil delivered per stroke.
Oil is discharged from each pump to the cylinder lubricating quills which are situated either towards the top or the bottom of the liner. The quills are arranged circumferentially around the liner, and locate in drillings in the liner wall. On the design illustrated the quill is of the type which passes through the cylinder cooling water space and so the quill passes through a sealing tube  as shown. This prevents oil contaminating the CW space or water entering the liner.
Correct cylinder lubrication achieves three main objectives: It forms a lubricating film between liner and rings, reducing wear and helping produce a gas tight seal; Due to its alkaline additives it protects the liner from acid attack (cold corrosion) and the detergent and dispersant additives help maintain the ring grooves in a clean condition, preventing carbon build up and ring jamming.
If the the lubricating oil is not supplied in sufficient quantity as per manufacturers instructions (0.7 - 1.3g/kwh depending on engine type), then liner wear rate will increase due to microsiezure and acid attack. Ring grooves may also coke up leading to broken rings. Using a cylinder oil with too low a BN (alkalinity) may lead to cloverleafing and blowby. An inspection of rings and liner can be done by viewing through the scavenge space. This will show up defects previously mentioned. Liner gauging carried out during overhaul will establish whether the wear rate is acceptable (0.05mm/1000hrs).
 
Labels:

Comments

Post a Comment

If you have any doubts.Please let me know

Popular posts from this blog

Differences between MC/MC-C and ME/ME-C engines

The electrohydraulic control mechanisms of the ME engine replace the following components of the conventional MC engine: Chain drive for camshaft Camshaft with fuel cams, exhaust cams and indicator cams Fuel pump actuating gear, including roller guides and reversing mechanism Conventional fuel pressure booster and VIT system Exhaust valve actuating gear and roller guides Engine driven starting air distributor Electronic governor with actuator Regulating shaft Engine side control console Mechanical cylinder lubricators. The Engine Control System of the ME engine comprises: Control units Hydraulic power supply unit Hydraulic cylinder units, including: Electronically controlled fuel injection, and Electronically controlled exhaust valve activation Electronically controlled starting air valves Electronically controlled auxiliary blowers Integrated electronic governor functions Tacho system Electronically controlled Alpha lubricators
9 comments
Read more

Main engine interlocks

Interlocks are provided so that the engine can be started or reversed only when certain conditions have been fulfilled. When there is a remote control of engines, it is essential to have interlocks. This reduces the possibility of engine damage and any hazards to the operating personnel. Turning gear Interlock . This device prevents the engine from being started if the Turning gear is engaged. Running Direction Interlock . This prevents the fuel from being supplied if the running direction of the engine does not match the Telegraph. Starting Air Distributor in end position . This prevents starting from taking place if the shifting of the Distributor has not been completed. Main Lube. oil pressure, Piston cooling pressure, Jacket water pressure, and important parameters must be above the required minimum. Auxiliary Blower Interlock . The Auxiliary Blower is provided in case of Constant pressure turbo charging. Air Spring pressure Interlock . In case of the present generation...
7 comments
Read more

Why is a man hole door elliptical in shape?

Any opening in a pressure vessel is kept to a minimum and for a man entry an elliptical hole  is lesser in size than the corresponding circular hole. More over it is prime concern to have a  smoothed generous radius at the corners to eliminate stress concentration. Hence other  geometrical shapes like rectangle and square are ruled out.  To compensate for the loss of material in the shell due to opening, a doubler ring has to be  provided around the opening. The thickness of the ring depends on the axis length along the  dirrection in which the stresses are maximum and the thickness of the shell. It is important to  align the minor axis along the length of the vessel, as the stress in this direction is  maximum. Longitudinal stress: Pd/2t where P= pressure inside the vessel, d= diameter of the arc, t=  thickness of the shell plating  Circumferential stress: Pd/4t  More over a considerable material and weight saving is achieved as...
20 comments
Read more