The Oil Pump is the core component of the engine lubrication system,known as the"blood heart"of the engine.Its main function is to deliver pressure oil to various moving parts of the engine.The high-speed running components such as crankshaft,connecting rod,piston,camshaft,valve,Turbocharger,etc.all rely on the oil delivered by the oil pump to achieve lubrication,cooling,cleaning,and sealing.If the oil pump works abnormally,serious faults such as bearing burnout,crankshaft locking,and cylinder pulling and pounding may occur in a short period of time,directly causing the engine assembly to be scrapped and resulting in huge losses.

　　The commonly used oil pumps for excavators are divided into two types:gear type and rotor type.The gear oil pump relies on a pair of meshing gears to generate suction force,which sucks in oil from the oil pan,pressurizes it,and delivers it to the main oil passage;The rotary oil pump relies on the eccentric rotation of the inner and outer rotors to achieve oil suction and pressure,with a compact structure and low noise.Nowadays,most electronic fuel injection excavator engines commonly use rotary oil pumps.The oil pump is generally driven by the crankshaft or gear mechanism.When the engine is running,the oil pump works synchronously,and when the engine is stopped,the oil pump immediately stops running.

　　The engine oil enters the oil pump from the oil pan through the oil collection filter,and is pressurized before being delivered to the main oil passage of the engine.It is supplied to the crankshaft connecting rod bearing,the cylinder head lubrication valve mechanism,and a portion to the turbocharger.A pressure limiting valve will be installed in the system.When the oil pressure is too high,the pressure limiting valve will open to release pressure,preventing the oil seal and gasket from being damaged by the high pressure in the oil pipeline;When the pressure is too low,the oil pump should fully supply oil to maintain normal working oil pressure.

　　Many operators tend to overlook the oil pump,thinking that it is not easily damaged.In fact,the oil pump on the machine does not directly display faults to the outside world,and the faults are all indirect outbreaks.The daily observation of the oil pressure warning light on the dashboard is the most intuitive feedback on the working status of the oil pump.When the car is cold,it is normal for the oil viscosity to be high and the pressure to be high.When the car is hot,the idle oil pressure is too low,which mostly indicates problems such as oil pump wear and clogged filters.The price of the oil pump itself is not expensive,but the cost of engine maintenance caused by its failure is extremely high.Fully understanding the functional principle of the oil pump can help us avoid major engine accidents in advance.