The high-pressure fuel pump,commonly known as the diesel large pump,is the core component of the fuel system in diesel engines and is known as the heart of the diesel engine.The mechanical pump model pressurizes diesel and directly delivers it to the fuel injector;The electronically controlled common rail model pressurizes diesel and delivers it to the common rail pipe,establishing a high pressure of tens to hundreds of megapascals to provide high-pressure fuel to the injectors,determining engine start-up,power,fuel consumption,and exhaust performance.

　　High pressure Oil Pumps are generally driven by engine gears or camshafts.The mechanical inline pump relies on the reciprocating motion of the internal plunger to complete oil suction,pressurization,and supply,and the speed control mechanism controls the oil supply amount;The common rail high-pressure pump first draws diesel from the fuel tank through the fuel transfer pump,filters it through the diesel filter,and enters the plunger chamber of the high-pressure pump.The plunger compresses to generate ultra-high pressure,which is controlled by the SCV metering solenoid valve to regulate the fuel intake and control the common rail pipe pressure.The ECU adjusts the oil pressure in real time based on the speed and load.

　　The entire assembly includes a pump body,plunger,oil outlet valve,and drive mechanism.The common rail model adds a metering solenoid valve and a pressure relief component.Diesel is not only a working medium,but also plays a lubricating and cooling role for the precision components inside the oil pump.Moisture and impurities in diesel can directly strain the plunger and pump barrel,causing early damage to the oil pump.

　　Excavators have complex working conditions,and the oil pump outputs a large flow rate for a long time when the mine is overloaded;The medium load condition of earthwork is relatively stable.The malfunction of the high-pressure oil pump is relatively concealed and will not be directly reported as a fault code.It often manifests as difficult starting,poor power,black smoke,fuel consumption,and idle shaking.Many operators tend to attribute faults to the fuel injectors and overlook the high-pressure pump itself.

　　The high-pressure oil pump is a high-precision component,with a clearance of micrometers between the plunger and pump barrel,making it difficult to maintain.Once the plunger wears out,professional pump calibration is mostly required,and if it is severely damaged,the assembly can be replaced directly.The price of oil pump accessories is high,and after a malfunction,the fuel injector will be damaged,which will double the repair cost.Familiarity with the working logic of high-pressure oil pumps and emphasis on diesel and filter maintenance can effectively prevent premature damage to the oil pump,reduce major engine failures,and ensure stable equipment construction.