A Brief Description of the Oil Transfer Pump and Its Overhaul

Definition: The oil transfer pump is able to guarantee diesel oil at low pressure inside the loop and supply sufficient quantities and to a certain pressure fuel injection pump. The quantity of oil transferred should be 3-4 times of the maximum loaded quantity of injection.

Category: gear oil pump, diaphragm pump, piston pump, pipeline pump and so on.
How it works:
1, the process of preparing: With the rotation of the fuel injection pump’s camshaft, the eccentric wheel pushes the roller, plunger and piston outward. The oil pressure raises in the pump chamber I due to a decrease in volume. At the same time, with the closing of the inlet valve 3, and the opening of the delivery valve 15 under pressure, the diesel then pumps flow from the chamber I, through the delivery valve and into the pump chamber 2.
2, Suction and pressure stroke: When the convex portion of the eccentric wheel turns away from roller, with the action of the spring, the plunger pushes inside. Then the oil pressure increases in the pump chamber 2, and the oil valve is closed, meanwhile the diesel flow through the pile to the oil filter diesel. In this case, the pump volume of the chamber 1 becomes larger, and the pressure drops. As the inlet valve 3 is sucked on, the diesel flows through the inlet and then the inlet valve into the pump chamber 1.
3, the automatic adjustment of the amount of oil: the amount of oil transported depends on the piston stroke, as well as the oil pressure depends on the tension of the spring. When the piston stroke is equal to the eccentric eccentricity, the amount of oil is max. When the amount of oil required reduces, the hydraulic pressure of chamber 2 will increases accordingly and there will be an idle stroke between the push rod and the piston. That is, the effective stroke of the piston is reduced, as well as the decrease of the output of oil. When the fuel consumption increases, the effective stroke is increased. Thus, the aim of the automatic adjustment of the amount of oil and the oil pressure is achieved.
Failure reasons of the pumps:
In general, the mechanical pump is very reliable. Esven if a fault appears, it is often a lack of oil transportation caused by the rupture of diaphragms. Sometimes, excessive wear of pump rocker arm or spring, can also cause the oil transportation shortage, which is very easy to identify. The old-fashioned pumps are repairable, whereas the new types of pump cannot be removed; therefore once there is a fault, the pump is needed to be replaced.
Repair methods:
1, Check the push rod in the pump first, which drives the work of the diaphragm. Block the pump inlet with your fingers gently, and try to start the engine. At this time, if there is a feeling of suction, then it proves that the push rod is intact.
2, On the other hand, if you feel no suction of the finger tips, it is indicated that the push rod is damaged, and fuel pump should be replaced. As the electric fuel pump working, if there is a powerful pumping sound, it indicates that the pump is in good condition, if not, it is an indicating of malfunction.
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