In a hydraulic system, the hydraulic pump is used as a power component, and several processes are required in the work. We can take a look at the workflow of Parker plunger pumps in operation with Terry, product application technical engineer of A&S Hydraulic Parts Co., Ltd.
The Parker plunger pump is roughly divided into three processes during operation: oil intake, oil supply and oil return.
Oil intake process:
When the protrusion of the cam is somewhat turned, the plunger moves downward, and the upper space of the plunger (called the pump oil chamber) is vacuumed. When the upper end of the plunger is placed on the plunger After the oil inlet hole is opened, the diesel oil filled in the oil passage of the oil pump enters the pump oil chamber through the oil hole, and the plunger moves to the bottom dead center, and the oil is completed.
Oil supply process:
When the camshaft turns to the cam to protrude from the roller body, the plunger spring is tightened, the plunger moves upward, the fuel is pressurized, and some fuel flows back through the oil hole to the body oil chamber of the fuel injection pump. When the top surface of the plunger covers the upper edge of the oil hole of the sleeve, the pumping chamber at the top of the plunger becomes a sealing oil chamber due to the small clearance of the plunger and the sleeve, and the plunger continues to rise, the pump The oil pressure in the oil chamber is actively increased. When the pump oil pressure is greater than the oil outlet valve spring force + the high pressure oil pipe remaining pressure, the oil valve is pushed open, and the high pressure diesel oil enters the high pressure oil pipe through the oil discharge valve and is injected into the combustion chamber through the fuel injector. .
Oil return process:
The plunger supplies oil upwards, and when it goes up to the chute (stop supply side) on the plunger and the oil return hole on the sleeve, the low pressure oil passage of the pump oil chamber and the middle hole and the radial hole of the plunger head And the chute exchange, the oil pressure is suddenly reduced, the oil discharge valve is closed under the result of the spring force, and the oil supply is continued. After that, the plunger is still going up. When the cam's protrusion is turned to the past, the plunger is descending again under the result of the spring. The next cycle begins.
In operation, the Parker plunger pump moves the plunger in the Parker piston pump up and down in the operation of the cam on the camshaft of the fuel injection pump and the pump spring to achieve the purpose of oil supply, oil supply and oil discharge. This is how the Parker plunger pump works.