What are the functions of hydraulic pumps? It includes hydraulic pump oil suction, oil pressure, and hydraulic pump oil volume adjustment. Let me tell you about these aspects:
Hydraulic pump suction and pressure oil
The reciprocating action of the plunger in the plunger sleeve completes the oil suction and oil pressure of the jet hydraulic pump. The two oil holes on the plunger sleeve are opened when the plunger is lowered, the inner cavity of the plunger sleeve is connected to the oil tube in the pump body, and the fuel oil swiftly fills the oil chamber. The plunger is raised when the cam is pressed against the roller of the roller body. Start at the bottom of the plunger and work your way up until the oil hole is stopped by the plunger’s upper end face. The gasoline is squeezed out of the oil chamber and flows to the oil route at this time due to the movement of the plunger. Pre-travel is the name given to this lift. The oil pressing process begins when the plunger blocks the oil hole. When the plunger is raised, the oil pressure in the oil chamber increases dramatically. The oil outlet valve is opened when the pressure surpasses the spring force of the oil outlet valve and the higher oil pressure, and the fuel is squeezed into the oil pipe and fed to the injector.
The potential oil supply starting point is when the oil inlet hole on the plunger sleeve is entirely blocked by the upper-end face of the plunger. When the plunger continues to move upward, so does the oil supply. The oil pressure is maintained until the plunger’s helical bevel allows the plunger sleeve to return to the oil hole. The high-pressure oil pours from the oil chamber through the oil hole when it is opened. The oil returns to the oil route in the pump body through the longitudinal groove on the plunger and the oil return hole on the plunger sleeve. The oil pressure in the plunger sleeve’s oil chamber rapidly drops, the oil outlet valve falls back to the valve seat due to the oil pressure in the spring and the high-pressure oil pipe, and the injector immediately stops pumping gasoline. The oil supply has been cut off at this time, even though the plunger is still moving higher. The theoretical endpoint of the oil supply is when the oil return hole on the plunger sleeve is opened by the oblique edge of the plunger. Only the middle stroke of the plunger’s upward movement is the oil pressure process, and this stroke is referred to as the effective plunger stroke.
Hydraulic pump oil volume adjustment
The fuel supply of the hydraulic injection pump must be able to be changed within the range of maximum fuel supply (full load) to zero fuel supply to fulfill the needs of the diesel engine load (stop). The gear rod and revolving sleeve modify the oil supply by causing all of the plungers in the jet hydraulic pump to rotate at the same time. The oil supply start time remains constant while the plunger spins, but the oil supply end time changes due to the oblique edge of the plunger changing the position of the plunger sleeve’s oil return hole. The effective stroke of the plunger varies with the angle of rotation of the plunger, hence the volume of oil supplied varies as well. The greater the distance between the top end face of the plunger and the oblique edge of the oil return hole that opens the plug sleeve, and the bigger the amount of oil supply, the greater the angle at which the plunger spins relative to the non-oil supply level 1. If it’s little, the oil cutoff occurs sooner, and the supply of oil is likewise limited. The oil must be turned off when the diesel engine is turned off. To do this, the plunger’s longitudinal groove can be turned to face the oil return hole on the reservoir. The fuel in the plunger sleeve has been flowing back to the oil route through the longitudinal groove and the oil return hole during the entire plunger stroke, and there is no oil pressure process, so the fuel supply is zero. The oil supply quantity is modified by adjusting the timing of the oil supply amount’s termination point as the plunger rotates. The oil supply endpoint adjustment method is the name for this method.
The hydraulic pump’s oil supply volume should be sufficient to suit the diesel engine’s needs under a variety of operating situations. The hydraulic pump shall ensure that the start time of the oil supply of each cylinder is the same, that is, the oil supply advance angle of each cylinder is the same, and that the oil supply is also guaranteed, according to the specifications of the diesel engine. The length is the same, and the emergency gasoline delivery begins fast, with the fuel stop being rapid and clean to avoid oil spilling. The hydraulic pump must give enough fuel pressure to the injector, depending on the shape of the combustion chamber and the technique of creating the mixture, to ensure good atomization quality.