Judgment standard for cleaning, maintenance and damage of skf bearings
Although the skf bearing has the characteristics of high performance, it can be damaged as a part of the machine, so some correct methods can extend its service life to a certain extent.
1. Cleaning of skf bearings
When disassembling the imported bearing for maintenance, first record the appearance of the skf bearing, confirm the residual amount of lubricant, and wash the bearing after sampling the lubricant for inspection. As the cleaning agent, gasoline and kerosene are generally used.
The cleaning of the removed bearings is divided into coarse cleaning and fine cleaning. They are respectively placed in the container, and a metal mesh pad is placed at the bottom first, so that the skf bearing does not directly contact the dirt of the container. During rough cleaning, if the bearing is rotated with dirt, it will damage the bearing rolling surface, so be careful. In the rough cleaning oil, use a brush to remove grease and adhesions. After it is roughly clean, transfer to the fine cleaning.
Fine cleaning is to carefully clean the bearing while rotating in the cleaning oil. In addition, the cleaning oil should always be kept clean.
2. Overhaul of bearings
In order to judge whether the disassembled skf bearing can be used again, it is necessary to check after the skf bearing is cleaned, carefully check the state of the raceway surface, rolling surface, mating surface, the wear of the cage, the increase of bearing clearance and whether there is any Damage or abnormality due to reduced dimensional accuracy. For non-separable small ball skf bearings, use one hand to support the inner ring horizontally, and rotate the outer ring to check whether it is smooth.
For separable imported bearings such as tapered roller bearings, the rolling elements and the raceway surfaces of the outer ring can be inspected separately.
Since large bearings cannot be rotated by hand, pay attention to checking the appearance of rolling elements, raceways, cages, rib surfaces, etc. The higher the importance of skf bearings, the more careful inspections must be made.
3. Judgment criteria for bearing damage
The judgment of whether it can be reused is determined by considering the degree of damage of the skf bearing, mechanical performance, importance, operating conditions, and the period until the next maintenance. However, if there are the following defects, it can no longer be used, and a new bearing must be replaced:
(1) There are cracks or nicks on any of the inner ring, outer ring, rolling element and cage;
(2) Any one of the ferrule and rolling element is broken;
(3) There are significant scratches on the raceway surface, ribs and rolling elements;
(4) The cage is significantly worn, or the rivets are significantly loosened;
(5) There is rust and damage on the raceway surface and rolling elements;
(6) There are serious indentations and scratches on the raceway surface and rolling elements;
(7) There is obvious creep on the inner diameter surface of the inner ring or the outer diameter surface of the outer ring;
(8) The discoloration caused by heat is obvious;
(9) The skf bearing sealed with grease has obvious damage to the sealing ring or dust cover.
Analysis and Treatment of Abnormal Noise of Rolling Bearings in High and Low Temperature Test Chamber Compressors
The bearing is one of the more important components in the compressor of the high and low temperature test chamber, and how to maintain the motor bearing of the compressor will directly affect whether the motor of the high and low temperature test chamber can operate safely and efficiently. Therefore, it is very necessary to do a good job in the maintenance of the compressor bearing of the high and low temperature test chamber. Today we will focus on explaining the causes and treatment methods of abnormal noise in rolling bearings.
When the compressor motor of the high and low temperature test box is running, a screwdriver can be used, the tip is pressed against the bearing cover, and the ear is close to the wooden handle of the screwdriver to monitor the sound of the bearing. If the rolling element has a faint rolling sound in the inner and outer rings, and the sound is monotonous and uniform, making people feel relaxed, it means that the bearing is good and the motor is running normally. If you hear abnormal noise, you should analyze the cause and deal with it.
- If you hear obvious rolling and vibration sounds of rolling elements, it means that the bearing clearance is too large or severely worn and needs to be replaced.
- The sound of the rolling element is hoarse and the tone is heavy, indicating that the bearing lubricating oil is too dirty and there are impurities intrusion. It is necessary to clean the bearing with kerosene and replace with new lubricating oil.
- The rolling elements have irregular impact sound, indicating that the bearing has individual rolling elements that are broken and need to be replaced.
- The whistle-like sound, mixed with the rolling sound of the rolling elements, indicates that the compressor bearing of the high and low temperature test chamber lacks lubricating grease or the lubricating oil is improperly selected. It is necessary to add clean lubricating oil or replace the appropriate lubricating oil.