Precautions for the use of automobile water pump shaft bearings

Precautions for the use of automobile water pump shaft bearings

1. Prevention of assembly foreign matter

When the bearing is installed on the rotor for dynamic balancing, it is easy to enter the iron filings generated during the dynamic balancing into the inside of the bearing, so it is best to perform dynamic balancing before installing the bearing. Some manufacturers apply some oil or grease to the bearing chamber for lubrication in order to facilitate assembly. However, it is often difficult for the operator to control the amount. If a lot of oil or grease accumulates in the bearing chamber, the bearing rotates on the water pump shaft. It is easy to enter the inside of the bearing along the shaft. It is best not to apply oil or grease to the bearing room. If it is not possible to apply it, it must be controlled not to accumulate in the bearing room.

2. Prevention of paint rust

The characteristic of lacquer rust is that it mostly occurs in sealed motors. The motor sounds very good during assembly, but after some time in the warehouse, the abnormal noise of the motor becomes very large, but the imported bearing of the water pump shaft is removed and there is serious rust. In the past, many manufacturers thought it was the problem of imported bearings, but now they have realized that it is mainly the problem of insulating paint. Such a problem occurs mainly because the acidic substance volatilized from the insulating paint forms corrosive substances at a certain temperature and humidity, which causes the bearing to be damaged after corroding the bearing channel. The only way to solve the problem is to choose a good insulating paint and ventilate for a period of time after drying and then assemble.

3. Selection and control of tolerances of shafts and bearing chambers

After the water pump shaft bearing is pressed into the imported bearing, it should rotate flexibly without any sense of blocking. If the rotation is obviously not flexible, it indicates that the size of the shaft is too large and the tolerance needs to be lowered. If the water pump shaft and the imported bearing are pressed into the shaft and the shaft is turned by hand, there is an obvious "sand" feeling, it may be that the shaft tolerance is too large or the roundness of the shaft is not good. Therefore, when controlling the tolerance of the shaft and the bearing chamber, the roundness must be controlled. Many domestic manufacturers only control the tolerance but not the roundness.

4. The assembly method of the bearing

Because the bearing is a high-precision product, improper assembly of the water pump shaft can easily cause damage to the bearing channel of the water pump shaft and cause bearing damage. When assembling the bearing, a special mold should not be knocked at will. When the shaft is pressed into the shaft, only the small circle can be forced, and when the large circle is pressed, only the large circle can be forced. Air pressure or hydraulic pressure is required when assembling, and the up and down touch should be outside the horizontal state during press-fitting. If there is an inclination, the bearing channel will be damaged due to the force, which will cause the bearing to produce noise.