Problems to be paid attention to in automobile water pump coupling bearings

In the cylinder of the car engine, there is a water channel for the circulation of cooling water, which is connected to the radiator (commonly known as the water tank) placed at the front of the car through the water pipe to form a large water circulation system. The water outlet on the engine , Equipped with a water pump, driven by the fan belt, pump out the hot water in the water channel of the engine cylinder, and pump the cold water in. There is also a thermostat next to the water pump. When the car is first started (cold car), it will not open so that the cooling water does not pass through the water tank, but only circulates in the generator (commonly known as small circulation), and waits for the temperature of the generator to reach When the temperature is above 80 degrees, it turns 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 steel balls and rollers of the water pump shaft bearing are usually made of high chromium bearing steel, and the materials of the shaft and outer ring are made of carburized steel or high chromium bearing steel. When the shaft material is made of carburized bearing steel, the hardness of the shaft raceway is usually 60-64HRC; the hardness of the shaft made of high chromium bearing steel is usually 58-62HRC; the hardness of steel balls and rollers is 61-65HRC; outer ring The hardness is usually 60-64HRC.

1. Avoid assembly foreign matter?

When the imported bearing is installed on the rotor for dynamic balancing, it is easy for the iron filings generated during the dynamic balancing to enter the imported bearing? Therefore, it is best to perform dynamic balancing before installing the imported bearing. Some manufacturers apply some oil or grease to the imported bearing chamber during assembly for easy assembly? But it is often difficult for operators to control the amount. If more oil or grease accumulates in the imported bearing chamber? In the water pump shaft When the imported bearing rotates, it is easy to enter the inside of the INA imported bearing along the shaft. It is best not to apply oil or grease to the imported bearing room. If it must be applied, it must be controlled not to accumulate in the imported bearing room.

2.Prevention of paint rust?

The characteristic of lacquer rust is that it mostly occurs in the sealed motor? The motor sounds very good during assembly? But after some time in the warehouse? The abnormal noise of the motor becomes very large. Remove the water pump shaft and the imported bearing. There is serious rust. . In the past, many manufacturers thought it was the problem of imported bearings? After our frequent publicity? Now the motor factory has realized that it is mainly the problem of insulating paint. The problem is mainly due to the acidic substances volatilized from the insulating paint that constitute corrosive substances at a certain temperature and humidity. The imported bearing grooves are corroded and the INA imported bearings are damaged. Before the title of the question, you can only choose a good insulating paint and ventilate for a period of time after drying and assembly.

3. How to choose and control the tolerance of shaft and imported bearing room?

After the water pump shaft is connected to the imported bearing, it should be rotated sensitively without any sense of blocking after being pressed into the imported bearing. If there is obviously insensitive rotation? It indicates that the size of the shaft is too large? The tolerance should be lowered. If the water pump shaft and the imported bearing are pressed into the shaft, there is an obvious feeling of "sand" when rotating by hand? It may be because the tolerance of the shaft is too large or the roundness of the shaft is not good. Therefore, when controlling the tolerance of the shaft and the imported bearing room, the roundness must be controlled. At present, many domestic manufacturers only control the tolerance but not the roundness.

4. How to assemble imported bearings?

Because the imported bearing is a high-precision product, improper assembly of the water pump shaft and shaft can easily damage the water pump shaft and the imported bearing channel and cause damage to the INA imported bearing. Imported bearings should have a special mold when assembling. They cannot be knocked at will. When pressing into the shaft, only the small circle can be forced? When the large circle is pressed, only the large circle can be forced. When assembling, it is required to use air pressure or hydraulic pressure. When pressing, the upper and lower touches must be external. If the state is inclined, it will cause the imported bearing channel to be damaged by the force. The imported bearing will cause noise.