Maintenance Methods For Water Pump Bearings

Jul 12, 2025

Can you maintain the water pump bearings?

1. Newly put into use water pumps generally require the replacement of lubricating grease (oil) after 100 hours of operation, and then every 500 hours of operation thereafter.

2. For flow bearings lubricated with grease, after 1500 hours of operation, the grease should be replaced and the amount of oil added should not be too much or too little, as too much or too little grease can cause the bearing to heat up. The amount of oil added is generally controlled at 1/2 to 2/3 of the bearing chamber volume.

3. For bearings lubricated with lubricating oil, the amount of oil should be added to the specified position.

4. The container for storing lubricating oil or grease should be clean, sealed properly, and free of dust, iron filings, and other debris to avoid damaging the bearings.

5. Sodium based grease is generally used for motor bearings, which is characterized by high temperature resistance (125 ℃), but is easily soluble in water, so it cannot be used for lubrication of water pump bearings.

The following are the issues to be noted when disassembling and assembling bearings:

(1) The drag force should continue to the appropriate level. For example, when installing a screw pump bearing, the force should be stopped when the bearing is just installed in the correct position, ensuring that the end face of the ring (washer) is pressed against the seat hole or the shoulder end face of the shaft, neither too tight nor not installed in place.

(2) The resultant force of the applied force should pass through the axis of the oil-free bearing as much as possible, which requires the application point of the plastic pump to be uniform, symmetrical, and smooth, and applied through a spherical surface or parallel to the axis.

(3) To avoid applying force through rolling elements, the diaphragm pump requires applying force through the inner ring (shaft ring) when installing and removing the inner ring, and applying force through the outer ring when installing and removing the outer ring.

(4) The magnitude of the applied force should be smooth and uniform, without any impact. For self-priming pumps, it is necessary to use oil pressure or tools that can apply stable tension or pressure. If hammering is necessary, it should also be buffered by softer and less debris free metals such as copper sleeves, and the impact force should be as light and gentle as possible. It is best to use a copper rod or copper hammer for hammering.