working principle of water pump

- Mar 16, 2020-

In the cylinder of a car engine, there are multiple water channels for cooling water circulation. They are connected to a radiator (commonly known as a water tank) placed in the front of the car through water pipes to form a large water circulation system. There is a water pump which is driven by the fan belt to pump out the hot water in the engine block water channel and pump in the cold water. There is also a thermostat next to the water pump. When the car is just started (cold car), it will not open, so that the cooling water does not pass through the water tank, and only circulates in the engine (commonly known as small circulation). When it is turned on, the hot water in the engine is pumped into the water tank, and the cold wind when the car is moving forward blows through the water tank, taking away the heat.

The engine drives the water pump bearing and impeller through the pulley, and the coolant in the water pump is driven by the impeller to rotate together, and is thrown away by the centrifugal force

To the edge of the pump casing, a certain pressure is generated at the same time, and then it flows out of the water channel or water pipe. The pressure at the center of the impeller is reduced because the coolant is thrown out. The coolant in the water tank is sucked into the impeller through the water pipe under the pressure difference between the pump inlet and the center of the impeller to achieve the reciprocating circulation of the coolant.

The bearing that supports the pump shaft is lubricated with grease. Therefore, it is necessary to prevent the leakage of the cooling fluid to the grease to cause emulsification of the grease, and also to prevent the leakage of grease. Water pump seals to prevent leakage are water seals and gaskets. The water seal moving seal ring and the shaft are installed between the impeller and the bearing through an interference fit, and the water seal static seal seat is tightly press-fitted on the casing of the water pump, thereby achieving the purpose of sealing the coolant.

The pump casing is connected to the engine through a gasket and supports moving parts such as bearings. The pump casing also has a drain hole, located between the water seal and the bearing. Once a coolant leaks through the water seal, it can be drained from the drain hole to prevent the coolant from entering the bearing cavity, which can damage bearing lubrication and cause component corrosion. If the coolant still leaks after the engine is stopped, the water seal is damaged.