Jacking Oil Pump-Main Turbine

Jacking Oil Pump

Function

• The jacking oil pump is a self-priming screw- spindle pump with three spindles and internal bearings.
• The pump supplies the jacking oil that is needed for lifting the shafting at low speeds 

Construction, Mode of Operation

• The screw-spindle pump is connected vertically to the cover plate (2) of the main oil tank via a support (5) and immerses with the suction casing (15) into the oil, The drive is an electric motor that is bolted to the cover plate (2). 
• The oil now into the suction branch of the suction casing (15) from underneath and is supplied to the lifting oil system by the pump via the pressure pipe (3). 
• The driving spindle (16) and the two moving spindles (20) run in the inner casing (13). 
• The fluid pressure to which the spindle thread is subjected on the pressure side is compensated by the driving spindle by means of the balancing piston (shrunk-on sleeve) running in the throttle bushing (11). 
• With the hollow moving spindles, the axial thrust is compensated by the balancing pistons arranged on the suction side which run in the balancing bushings (21). 
• The throttle bushing (11) and the driving spindle (16) form a throttling gap that separates the pressure area from the following area. 
• The oil that leaves the  throttle gap. flows via the grooved ball bearing (7) into the support and from there back into the main oil tank. 
• The grooved ball bearing is lubricated with this oil. The driving spindle is fixed by means of the grooved ball bearing in the bearing carrier (9) that is bolted to the pressure casing (12) of the pump. 
• Due to the special profile given by the sides of the threads the three spindles form sealed chambers, the contents of which are continuously being moved axially from the suction side to the pressure side of the pump as the spindles rotate.
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