Analysis of common faults in centrifugal pumps - bearings

The limit value of bearing temperature for centrifugal pumps during operation is 75 ℃. If the temperature of the bearing exceeds 75 ℃, it is a heating phenomenon caused by a fault, and in severe cases, it can cause the bearing to burn out. There are several reasons for bearing heating:
① Bearings lack oil or have excessive grease. Adding an appropriate amount of grease to the bearing box can not only provide lubrication, reduce friction resistance, but also provide heat dissipation. Lack of oil can increase the friction resistance of the bearing, causing it to heat up and increase the temperature. However, excessive oil can also increase the friction resistance and poor heat dissipation, which can also cause the bearing to heat up and increase the temperature.
Troubleshooting: Add lubricating grease or reduce the amount of lubricating grease appropriately. Practice has proven that it is generally suitable to fill the bearing disc with 1/3 to 1/2 of lubricating grease.
② There is no gap at the bearing end cover. After installing the bearing end cover, there should be a certain gap at one end. If there is no gap, when the main shaft of the pump is extended due to heating during operation, it will cause the two bearings and bearing end caps to jam, and the bearing temperature will increase.
Troubleshooting: Add paper pads and adjust the gap.
③ The belt is pulled too tight. The belt is too loose and can easily slip. Reducing the speed of the pump can cause insufficient or no water output, but if the belt is pulled too tightly, it will increase the pump's axial force, increase frictional resistance, heat up the bearings, and increase the temperature.
Troubleshooting: Adjust the tightness of the belt appropriately.