Early preventive maintenance of bearings

When considering the lubrication aspect, Bearing Distributors Inc generally only checks the oil usage and adds grease to the bearing. A newer preventive maintenance method has clearer requirements for lubrication, including the condition, use and value of the lubricant, and Bearing life can be greatly extended under certain special conditions, especially when the load is reduced. When the rolling surface of the bearing (the bearing race and the rolling member) is effectively separated by a layer of lubricating oil film and the surface damage caused by contamination is limited, the life of the bearing can be extended. Therefore, preventive maintenance of bearings is especially important. Users should pay attention to the following points during maintenance and preventive maintenance:
1 good lubrication
The three main reasons why bearings need lubrication are: reducing the friction between the bearing track, the rolling elements and the cage; protecting the abrasive surface from corrosion; In order to achieve better operating conditions, it is necessary to choose the correct lubrication method. At present, there are two general lubrication methods: oil and grease.
1 .1 oil lubrication
Although grease lubrication is easier and more convenient to operate than oil lubrication, it is better to use oil lubrication under certain conditions of use, especially when bearing heat is removed. In general, there are two tendencies when choosing oil lubrication: a small amount of lubricating oil or a large amount of lubricating oil. For bearing lubrication, a small amount of oil is generally required, because the thickness of the oil film existing between the rolling element and the rail is much less than 0.001 mm, so a small amount of oil can cover the entire bearing surface to avoid corrosion. Excessive oil will create resistance during operation, causing energy consumption. At high speeds, a large amount of lubricant must be used to remove the heat generated by the friction to maintain a low bearing temperature. When using a large amount of lubricating oil, it is necessary to increase the horsepower to overcome the damping caused by the increase in speed, and to use a certain cooling method to cool the lubrication.
oil.
1 .2 Grease lubrication
The main advantage of grease lubrication is economical. Maintenance-free oil supply over a long period of time saves many devices in the external fuel supply system. When selecting grease, pay special attention to the amount of grease and leave enough space for excess grease to be discharged during operation. The amount recommended is based on 30% of the internal space. If you want to use a small amount of grease to achieve high speed, it is recommended to soak the bearing in the solution in which the grease is suspended, remove the liquid to be dissolved, and then apply grease. According to the above two points, no matter which lubrication method is selected, the oil or grease on the bearing must be cleaned before maintenance, and the original inner and outer rings should be kept as much as possible. If replacement is required, it must be done in sets to ensure an accurate combination.
2 Lubrication of lubricating oil
In recent years, the bearing capacity of rolling bearings has been greatly improved. The main reason is the use of purer steel and smoother surfaces. On the other hand, the filtration of lubricating oil has been continuously improved. This explains that part of the life of the bearing is prolonged because the lubricant is cleaner, so the user can directly decide how much attention should be paid to the cleanliness of the lubricant. Lubricating oil is actually free of moisture, but when it is operated outdoors and the machine itself contains moisture or steam, the lubricating oil is highly susceptible to water contamination and shortens bearing life.
In general, the selected filter should be able to retain at least as few particles per hour as the number of particles produced by bearing wear. Filters of appropriate grade and flow rate should be selected.
3 Size of particulate pollutants
Dirt entry is the most common cause of bearing damage. When dirt enters the lubrication system, the bearing and raceway rolling surfaces begin to accelerate wear. All particulate contaminants larger than the oil film thickness can cause permanent damage to the bearing before being ground. The main reason is that when the rolling elements of the bearing are rolled through the granular dirt and the worn debris, indentation is caused on the rolling surface of the bearing, and these indentations cause stress concentration, causing surface fatigue, thereby causing early damage of the bearing. Therefore, in selecting the grease, the maximum volume of the individual molecules of the particulate contaminants inside the grease must be considered, as well as the contaminant content within a certain weight range. In short, the user should pay special attention to the use conditions and usage of the lubricating oil when maintaining the bearing. Whether the moisture content or the pollutant content in the rolling bearing should be controlled as low as possible to reduce the wear on the bearing. Improve the efficiency of car operation.