Method for checking whether the bearing lubricating oil has deteriorated

Method for checking whether the bearing lubricating oil has deteriorated

Lubricating oil is very important for the operation of bearings, and the quality of lubricating oil directly affects the service life of bearings, especially SKF bearings have 

higher requirements for lubricating oil. If the quality of the lubricating oil is poor or deteriorates, it will directly affect the operation and service life of the bearing, so it 

is necessary to ensure that the lubricating oil does not deteriorate.

The importance of lubricating oil to bearings goes without saying, so it is necessary to constantly check the lubricating oil when using bearings to ensure that the grease 

has not deteriorated. The methods for checking whether the bearing lubricating oil has deteriorated mainly include the following:

1. Oil flow observation method: Take two measuring cups, one containing the lubricating oil to be inspected and the other empty on the table. Raise the measuring cup 

filled with lubricating oil 30-40 centimeters away from the table and tilt it, allowing the lubricating oil to slowly flow into the empty cup and observe its flow. Good quality 

lubricating oil should flow smoothly, evenly, and continuously; If the flow rate fluctuates between fast and slow, and sometimes large chunks flow down, it indicates that the 

lubricating oil has deteriorated.

2. Hand twisting method: Twist lubricating oil between the thumb and index finger and repeatedly grind. Good lubricating oil feels lubricating, with less debris and no friction; 

If you feel a strong friction sensation such as sand particles between your fingers, it indicates that there are many impurities in the lubricating oil and it cannot be used anymore. 

You should replace the lubricating oil with a new one.

3. Lighting method: On a sunny day, use a screwdriver to lift up the lubricating oil at a 45 degree angle to the horizontal plane, and observe the oil droplets against the 

sunlight. Under illumination, it is considered good if there are no debris in the lubricating oil that can be clearly seen; If there is too much debris, the lubricating oil should 

be replaced.

4. Oil droplet mark method: Take a clean white filter paper and drop a few drops of lubricating oil onto the filter paper. After the lubricating oil leaks, if there is black powder 

on the surface and there is a sense of resistance when touched by hand, it indicates that there are many impurities in the lubricating oil; Good lubricating oil has no powder, 

feels dry and smooth by hand, and shows yellow marks.

These methods can help you regularly check the condition of the bearing lubricating oil to ensure that it remains in good condition during use, thereby extending the service 

life of the bearing.