1.When the bearings have reached a certain period of operation (or maintenance period), remove all bearings

2. Soak the bearings in diesel or kerosene for cleaning. If there are technical conditions, it is best to open the sealing cover for cleaning

3.Inspect the appearance of the air dry cleaning oil after cleaning for any damage

4.Use a wooden rod (preferably a hollow tube) with a diameter of approximately 150mm and an equal inner diameter of the angular contact ball bearing to fix a bearing at one end

5. While quickly rotating the bearing by hand, place the other end of the wooden rod (tube) against the ear or audio amplifier microphone to listen for bearing rotation noise

6.After fixing the bearing, move the wooden rod horizontally to check whether the bearing is worn or loose

7.Bearings with severe looseness, excessive rotating noise, or serious defects should be replaced with the same model instead of being eliminated

8. Take a bucket and melt an appropriate amount of lubricating grease (high-quality yellow dry oil) with gentle fire (do not overheat). Soak the tested bearings in the bucket until there are no bubbles overflowing. Before the lubricating grease cools down, remove the bearings. Reduce the amount of residual lubricating grease. After the lubricating grease cools down, remove the angular contact ball bearings. Determine the amount of residual lubricating grease as needed

9.Clean the lubricating grease on the outside of the bearing with a soft cloth or toilet paper and assemble the bearing onto the pulley in its original state. The maintenance work is now completed