Features of rolling bearings

Compared with sliding bearings, rolling bearings have the following advantages:

1. Rolling bearings have realized generalization, serialization and standardization, which are more suitable for mass production and supply, and are very convenient for use and maintenance;
2. The friction coefficient of the rolling bearing is smaller than that of the sliding bearing, and the transmission efficiency is higher. The friction coefficient of sliding bearings is generally 0.08-0.12, while the friction coefficient of rolling bearings is only 0.001-0.005;
3. The rolling bearing has high running accuracy, its internal clearance is small, and the machining accuracy of each part is high. Rolling bearings can also increase the rigidity of the bearing by preloading. This is very important for precision machinery;
4. Rolling bearings not only have higher mechanical properties and longer service life. Rolling bearings are made of bearing steel and have been heat treated, which can also save expensive non-ferrous metals for manufacturing sliding bearings;
5. The rolling bearing has high transmission efficiency and low heat generation, which can reduce the consumption of lubricating oil and make lubrication and maintenance more convenient;
6. Some rolling bearings can bear axial load and radial load at the same time, which is beneficial to simplify the structure of the bearing support;
7. Rolling bearings can be easily applied to shafts in any orientation in space.

Relative to sliding bearings, rolling bearings also have the following disadvantages:

1. The load bearing capacity of the rolling bearing is smaller than that of the sliding bearing of the same volume. Therefore, the radial dimension of the rolling bearing is larger. In the occasions that need to bear heavy loads, small radial dimensions and compact structure requirements (such as internal combustion engine crankshaft bearings), sliding bearings are often used;
2. The vibration and noise of rolling bearings are relatively large, especially in the later period of use. Therefore, in the occasions that require high precision and no vibration, sliding bearings are generally preferred;
3. Once a foreign body enters the rolling bearing, it will produce large intermittent vibration and noise, which will also cause early damage. In addition, rolling bearings are also prone to early damage due to metal clamp impurities. Even if there is no early damage, the life of the rolling bearing will be reduced to a certain extent. In short, the life of rolling bearings is shorter than that of sliding bearings.