In the cylinder block of the automobile engine, there are several water channels for cooling water circulation, which are connected with the radiator (commonly known as the water tank) at the front of the automobile through water pipes to form a large water circulation system. The upper outlet of the engine is equipped with a water pump, which is driven by the fan belt to pump out the hot water in the water channel of the engine cylinder block and pump in the cold water. There is also a thermostat beside the water pump. When the car is just started (cold car), it is not opened, so that the cooling water does not pass through the water tank, but only circulates in the engine (commonly known as a small cycle). When the engine temperature reaches above 80 degrees, it is opened. The hot water in the engine is pumped into the water tank, and the cold air when the car is moving forward blows through the water tank to take away the heat.

Basic structure and working principle of automobile water pump:

Centrifugal pumps are widely used in automobile engines. Its basic structure consists of water pump housing, connecting disc or pulley, water pump shaft and bearing or shaft bearing, water pump impeller, water seal device and other parts.

The engine drives the water pump bearing and impeller to rotate through the belt pulley. The coolant in the water pump is driven by the impeller to rotate together. Under the effect of centrifugal force, it is thrown to the edge of the water pump housing. At the same time, it generates a certain pressure and then flows out of the water outlet or water pipe. The pressure at the center of the impeller is reduced due to the coolant being thrown out. The coolant in the water tank is sucked into the impeller through the water pipe under the pressure difference between the inlet of the water pump and the center of the impeller to realize the reciprocating circulation of the coolant.

The bearing supporting the water pump shaft is lubricated with grease, so it is necessary to prevent the coolant from leaking to the grease to cause the grease emulsion, and also prevent the coolant from leaking. Sealing measures to prevent leakage of water pump include water seal and gasket. The dynamic seal ring and shaft of the water seal are installed between the impeller and the bearing through interference fit, and the static seal seat of the water seal is tightly against the housing of the water pump to seal the coolant

The impeller is the core of the pump. The movement of the impeller itself is very simple, just rotating with the shaft. However, due to the role of the blade, the movement of the liquid in the impeller is very complex; On the one hand, it makes a implicated movement with the rotation of the impeller, on the other hand, it is constantly thrown out of the rotating impeller under the driving of the blade, that is, the movement relative to the impeller. Therefore, the outer diameter of the impeller, the height and angle of the impeller blade, and the clearance with the pump housing directly affect the performance of the pump.