Purpose and Mode of Lubrication
Purpose and Mode of Lubrication
2022年3月20日
Selection Principle of Vehicle lubricating Oil
Selection Principle of Vehicle lubricating Oil
2022年3月20日

Method for Judging Deterioration of lubricating Grease

In order to provide better performance during the operation of the bearing, grease is generally used to lubricate the bearing, which can reduce the increase of bearing operation friction and temperature. If the grease is deteriorated, it will not play a relevant role, but will be more unfavorable to the use of the bearing. Therefore, when purchasing grease, we must learn how to identify whether the grease has deteriorated.

Method for judging deterioration of lubricating grease:Method for Judging Deterioration of lubricating Grease

1. Oil flow observation method

Take two measuring cups, one containing the lubricating oil to be inspected and the other empty on the table. Lift the measuring cup filled with lubricating oil 30-40 cm away from the table and tilt it to let the lubricating oil flow slowly into the empty cup and observe its flow. The lubricating oil with good quality should flow slender, uniform and continuous. If the oil flow is fast and slow, and sometimes large pieces flow down, it means that the lubricating oil has deteriorated.

2. Hand twisting

Twist the lubricating oil between the thumb and index finger and grind it repeatedly. The better lubricating oil hand feels lubricity, less wear debris and no friction. If it feels a large friction feeling such as sand particles between the fingers, it indicates that there are many impurities in the lubricating oil and it can not be used again. It should be replaced with a new lubricating oil.

3. Illumination method

On sunny days, lift up the lubricating oil with a screwdriver at an angle of 45 degrees to the horizontal plane. Observe the condition of oil drops according to the sunlight. In the light, it can be clearly seen that there is no wear debris in the lubricating oil. It can continue to function. If there are too many wear debris, replace the lubricating oil.

4. Oil drop trace method

Take a clean white filter paper and drop several drops of oil on the filter paper. After the lubricating oil leaks, if there is black powder on the surface and there is a sense of astringency by hand, it indicates that there are a lot of impurities in the lubricating oil. Good lubricating oil has no powder and feels dry, smooth and yellow by hand.Method for Judging Deterioration of lubricating Grease

1. Oil drop trace method: take a clean white filter paper and drop several drops of lubricating oil on the filter paper. After the lubricating oil leaks, if there is black powder on the surface and there is a sense of astringency 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.Method for Judging Deterioration of lubricating Grease

2. Oil flow observation method: take two measuring cups, one of which holds the lubricating oil to be inspected, and the other empty cup is placed on the desktop. Lift the measuring cup filled with lubricating oil 30-40cm away from the desktop and tilt it, let the lubricating oil flow slowly into the empty cup, and observe its flow. The lubricating oil with good quality should flow slender, uniform and continuous.Method for Judging Deterioration of lubricating Grease

3. Illumination method on sunny days, lift up the lubricating oil inspection rod at an angle of 450 to the horizontal plane. Observe the oil drops of the lubricating oil according to the sunlight. In the light, it can be clearly seen that there is no wear debris in the lubricating oil. It can be used continuously. If there are too many wear debris, replace it with new oil.

4. Oil drop trace method: take a clean white filter paper and drop several drops of lubricating oil on the filter paper. After the lubricating oil leaks, if there is black powder on the surface and there is a sense of astringency by hand, it indicates that there are many impurities in the lubricating oil.Method for Judging Deterioration of lubricating Grease

1. The color turns black, indicating oxidative deterioration. If only one layer of the surface changes color, one layer of the surface can be scraped off and can still be used as usual. It is best to check the change of pH, that is, drop phenolphthalein indicator on a small amount of lubricating grease, mix it evenly, twist it with your fingers, if it is red, it means that the lubricating grease remains alkaline; Method for Judging Deterioration of lubricating Grease

If it does not change color, it indicates that the fat has become acidic. Generally speaking, the lubricating grease that becomes acidic cannot be used on valuable instruments to avoid corrosion, but it can be used in rough equipment that is not afraid of corrosion.Method for Judging Deterioration of lubricating Grease

 

2. The formation of adhesive film on the surface also belongs to oxidation, especially the lubricating grease made of dry vegetable oil, which is easy to occur. The treatment method is the same as above.

 

3. Oil precipitation indicates that colloidal stability has been destroyed. In case of slight oil precipitation, the surface oil can be removed, and most of the rest can still be used; But try not to use it in high temperature and high load parts. Products with serious oil separation cannot be used.

 

4. Due to absorption of water or leakage of rainwater, the oil is easy to produce surface emulsification. If the emulsified metamorphic part is completely removed, the remaining part can still be used. In case of serious emulsification, the water content of the remaining part may exceed the standard. This can be judged from the color. The more water, the lighter the color of the grease, the darker and opaque the luster.

 

5. One of the reasons for the thinning of lubricating grease is that the storage temperature is too high or the consistency cannot be restored, and the other reason is the change of pH

 

Method for judging deterioration of lubricating grease:

 

1. Oil flow observation method

 

Take two measuring cups, one containing the lubricating oil to be inspected and the other empty on the table. Lift the measuring cup filled with lubricating oil 30-40 cm away from the table and tilt it to let the lubricating oil flow slowly into the empty cup and observe its flow. The lubricating oil with good quality should flow slender, uniform and continuous. If the oil flow is fast and slow, and sometimes large pieces flow down, it means that the lubricating oil has deteriorated.

 

Method for Judging Deterioration of lubricating Grease

2. Hand twisting

Twist the lubricating oil between the thumb and index finger and grind it repeatedly. The better lubricating oil hand feels lubricity, less wear debris and no friction. If it feels a large friction feeling such as sand particles between the fingers, it indicates that there are many impurities in the lubricating oil and it can not be used again. It should be replaced with a new lubricating oil.Method for Judging Deterioration of lubricating Grease

3. Illumination method

On sunny days, lift up the lubricating oil with a screwdriver at an angle of 45 degrees to the horizontal plane. Observe the condition of oil drops according to the sunlight. In the light, it can be clearly seen that there is no wear debris in the lubricating oil. It can continue to function. If there are too many wear debris, replace the lubricating oil.

4. Oil drop trace method

Take a clean white filter paper and drop several drops of oil on the filter paper. After the lubricating oil leaks, if there is black powder on the surface and there is a sense of astringency by hand, it indicates that there are a lot of impurities in the lubricating oil. Good lubricating oil has no powder and feels dry, smooth and yellow by hand.Method for Judging Deterioration of lubricating Grease