Bearing life study: internal and external factors of double-row cylindrical roller bearing service life
WSBC believes that according to the latest rolling bearing fatigue life theory, a bearing with excellent design, excellent materials, superior manufacturing, and correct installation, as long as the load it bears is easy enough (not higher than a specific endurance limit load value corresponding to the bearing). The material of this bearing will never produce fatigue damage. Therefore, as long as the working environment temperature of the bearing is suitable and the change range is not extensive, there is absolutely no solid dust, harmful gases, and moisture intruding into the bearing, the lubrication of the bearing is sufficient and just right, the lubricant is pure without impurities, and will not age and deteriorate ... Then this bearing will run indefinitely.
The great significance of this theory is not only that it provides a more reliable tool for predicting the life of new bearings than the ISO life equation, but also that it shows that the fatigue life of all rolling bearings has considerable development potential and shows the development of this potential. The way of bearing has a profound influence on the event, quality management, and application technology of bearing products.
However, the infinite bearing can only be "achieved" under laboratory conditions, and such conditions are difficult and expensive for bearings used on-site under specific working conditions.
When the bearing is used on-site, its working load is often higher than its corresponding fatigue endurance limit load. After working to a certain period, it will always be used later due to its material, reaching the fatigue limit of the call, resulting in fatigue spalling. Even if the working load of some bearings is lower than their corresponding endurance limit load, wear and tear will occur due to the problematic bearing pollution problem. In short, the bearings in-field use are more or less inadequate to meet the conditions of the laboratory mentioned above, and any of these conditions is slightly insufficient, which will shorten the service life of the bearing, which has caused bearing life problems.
Generally speaking, the life of rolling bearings refers to the long service period of rolling bearings that can continuously maintain the working performance and working accuracy that meet the current requirements under actual service conditions (including working terms, environmental conditions, and maintenance and maintenance conditions, etc.).
WSBC bearings analyze the internal and external factors of the service life of double row cylindrical roller bearings
1. Bearing size limitation
Generally, there is limited space to install double row cylindrical roller bearings. In most cases, the shaft diameter (or bearing inner diameter) is based on mechanical design or other design constraints. Therefore, the choice of taking type and size depends on the inner diameter of the bearing. Thus, the main size table of standard bearings is compiled according to the international standard internal diameter size.
Standard double-row cylindrical roller bearings come in various sizes, and standard bearings are used in the design of mechanical equipment (this design determines whether the bearings are easy to buy. I will say that also, some bearing catalogs do have Models, but some are not applicable. There is no standard bearing in mainland China, and sometimes the futures will take a long time, so you must consider the cost of time and the cost of replacement in the selection of the bearing. The direction is variable. Generally, the rated constant load is shown on the dimension table. However, the axial load and radial load are also essential factors in choosing a suitable bearing.
2. Bearing speed
The allowable speed is determined by factors such as the type, size, accuracy, cage type, load, lubrication method, and cooling method of the double row cylindrical roller bearing. The bearing table lists the allowable speed of standard precision bearings under oil lubrication and grease lubrication. Generally, deep groove ball bearings, self-aligning ball bearings, and cylindrical roller bearings are suitable for high-speed operation.
3. Bearing tolerance
The dimensional accuracy and rotation accuracy of double-row cylindrical roller bearings are based on ISO and JIS standards. For machines that require high efficiency and high-speed operation, it is recommended to use bearings of grade 5 or higher. Deep groove ball bearings, radial thrust ball bearings or cylindrical roller bearings are suitable for machines with high running accuracy. Rigidity, when the contact surface of the rolling element of the bearing and the raceway is compressed, it will elastically deform. Some machines need to minimize elastic deformation. Rolling bearings produce less elastic deformation than ball bearings.
Wuxi Spark Bearing Co., Ltd focuses on the R & D and manufacturing of high-quality roller bearings and provides a full range of bearing services for the industry, sharing more bearing use knowledge with you.