Oil gear pump.Gear pumps with small dimensions , uniform oil supply , long service life and high reliability are the most widely used for low-pressure oil circulation system . These pumps can be driven directly from the motor ( non-reversible motors ) or independently driven by an electric motor ( reversible motors ) . In the latter case, the pump will have a more complex device .
Oil gear pump
A General view of the oil gear pump and a diagram explaining the principle of ero operation are shown in figure 149 . To cast iron body 1 with studs attached to both sides of the lid . Inside the body there is a driving gear 6, fixed with a key on the roller 5 , and the driven gear 2 , freely rotating on the axis 3 due to the bronze bushing pressed into its hub.Roller bearings 5 are also bronze bushings located in the pump covers .
At the end of the roller , the drive gear 4 is fixed, which receives rotation through the gear system from the engine crankshaft . Inside the body there are two pairs of suction and discharge valves, made in the form of light dampers, taken to the sockets by weak springs .
With the directions of rotation of the gears shown in figure 149, 6 arrows, the oil entering through the inlet 1 into the cavity 2, will be captured by the teeth of the gears 3 and 6, fill the cavities between the teeth and gradually removed from this cavity . Since the gears rotate continuously, a vacuum is formed in the cavity 2 and oil from the oil collector will be constantly absorbed here .
Oil gear pump The gap between the teeth of the gears and the walls of the housing is very small , so the gears , rotating will constantly transfer the oil located in the cavities of the teeth along the walls of the housing into the cavity 5 .
When the teeth enter the engagement , the oil will be squeezed out and pumped through the outlet 4 into the discharge line . When changing the direction of rotation of the gears, the process of suction and injection of oil is similar , but a parallel pair of valves ( suction and discharge) enters into operation.
Oil gear pump
When an engine Assembly requires increased lubrication pressure, oil plunger pumps are used, each of which can have its own plunger by individually adjusting the oil supply to a separate lubricated point . To maintain the circulating lubrication system of marine diesel engines, mechanical filters are most often used, which well retain solid particles and resinous substances in the contaminated oil . As a filter material they use metal mesh, cloth, felt paper and synthetic materials .
Double strainer coarse (figure-150) is made of two cast in one block of cast iron housings 1 , which are located in the filter cartridges 2 , consisting of metal mesh sandwiched between the disks . Each housing is closed with a cast iron cover 3, easily removable when cleaning the filter .
Oil gear pump On caps provided for valves 4 for the release of the who spirit , and in the bottom of the body – tube 7 or the taps 6 for removal of dirty oil . Three-way valve 5 is used to switch the oil flow from one filter housing to another in case of contamination of one of them .
Crude oil fills the annular space between the walls of the body and the filter . them patron . Under the pressure created by the oil pump, it passes through the outer side holes in the disks through the grids and the inner side holes of the disks enters the Central pipe , and from it into the upper filter cavity.
Fine filters, oils are similar designs, only the filter mesh cartridge (or frame ) is additionally stuffed with a layer of felt , cotton yarn or special filter paper that significantly increases the resistance of the filter reduces when . approximately 10 times ero performance .
Along with oil filtration in marine diesel installations , such methods of its purification as sludge and separation are used . The largest mechanical inclusions of moisture are separated as a result of sludge in spare oil tanks or in special devices called separators , which moisture and mechanical inclusions are separated from the oil by centrifugal force .
The design of the oil cooler used in the circulating oil system of the marine diesel installation is shown in Fig . 77. A similar design has a water refrigerator, but unlike the oil in his tubes flows cooled fresh water, and the outside cooling washes the tube.