The early car engines did not have the important accessories that we think are indispensable today-car water pumps. The liquid cooling medium used at that time was pure water, at most mixed with a little wood alcohol to prevent freezing. The circulation of cooling water relies entirely on the natural phenomenon of thermal convection. Using this thermosiphon principle can barely complete the cooling task. But not long after, auto electric water pump were added to the cooling system to move the cooling water more quickly.
The cooling system of modern automobile engines generally uses centrifugal water pumps. The reasonable installation position of the automotive water pump is at the bottom of the cooling system, but most of the water pumps are placed in the middle of the cooling system, and a few water pumps are placed on the top of the engine. The water pump placed on top of the engine is prone to cavitation. No matter where it is, the pumping volume of the automotive water pump is very large. For example, the pumping volume of the water pump of a V8 engine is about 750L/h at idle speed, and about 12000L/h at high speed.
From the perspective of service life, the biggest change in the design of automotive water pumps is the appearance of ceramic seals a few years ago. Compared with the rubber seals or leather seals used before, ceramic seals are more wear-resistant, but they also have The disadvantage of being easily scratched by hard particles in the cooling water. Although continuous improvements have been made in the design to prevent failure of the water pump seal, so far the seal of the water pump cannot be guaranteed to be free of problems. Once the seal leaks, the lubrication of the water pump bearings will be washed out.
The composition of automotive water pump is composed of a water pump housing, connecting plate or pulley, water pump shaft and bearing or shaft-connected bearing, water pump impeller and water seal device, etc., which are the main car cooling system parts of the car. The impeller is the core of the work of the automotive water pump. The movement of the impeller itself is very simple, it just rotates with the shaft. However, due to the action of the blades, the movement of the liquid in the impeller is very complicated; on the one hand, it moves with the rotation of the impeller, and on the other hand, it is continuously thrown out from the rotating impeller driven by the blades, that is, the movement relative to the impeller. Therefore, the outer diameter of the impeller, the height and angle of the impeller blades, and the gap with the automotive water pump casing directly affect the performance of the water pump.
In addition, the water tank of the car is filled with water, and the water inside is used for engine cooling. Both the water tank and the intercooler are installed in front of the engine on the front of the car. Generally, a car with an intercooler also has a supercharger mainly to reduce the intake temperature of the engine, thereby increasing the output power of the engine.