The function of the fuel transfer pump is to ensure that a sufficient amount of diesel oil is delivered from the fuel tank to the fuel injection pump, and to maintain a certain fuel supply pressure to overcome the resistance of the pipeline and the fuel filter, so that the diesel oil circulates in the low-pressure pipeline. Oil delivery: generally 3 to 4 times the full load requirement of the diesel engine. Types are divided into piston type, diaphragm type, sliding vane type and gear type.

working principle

1. Oil pressure preparation process: With the rotation of the camshaft of the fuel injection pump, the eccentric wheel pushes the roller, the push rod and the piston to move outward, and the oil pressure of the pump chamber I increases due to the decrease of the volume. The oil valve, the diesel oil flows from the pump chamber I to the pump chamber II through the oil outlet valve.

2. Oil suction and oil pressure stroke: When the raised part of the eccentric wheel turns away from the roller, the piston moves inward under the action of the spring, the oil pressure of the pump chamber II increases, the oil outlet valve is closed, and the diesel oil flows to the oil filter through the oil passage . At this time, the volume of the pump chamber I becomes larger, the pressure drops, the oil inlet valve 3 is sucked open, and the diesel oil flows into the pump chamber I through the oil inlet port and the oil inlet valve.

3. Automatic adjustment of oil delivery: the amount of oil delivery depends on the stroke of the piston; the oil delivery pressure depends on the tension of the piston spring. When the stroke of the piston is equal to the eccentric distance of the eccentric, the oil delivery volume Z is large. When the amount of oil required by the fuel injection pump decreases, the oil pressure in the pump chamber II will increase accordingly, and an idle stroke is generated between the push rod and the piston, that is, the effective stroke of the piston is reduced, and the output oil volume is reduced. When the fuel consumption increases, the effective stroke increases. In this way, the automatic adjustment of oil delivery volume and oil delivery pressure is realized.

4. Hand pump oil: pull the hand oil pump piston, absorb oil and press oil.