In the world of mechanical engineering, bearings play a crucial role in ensuring the smooth and efficient operation of machinery. Among the various types of bearings, rolling bearings and sliding bearings are the most commonly used. Each has its unique design, functionality, and applications, making them suitable for different industrial needs.

This article delves into the advantages and disadvantages of rolling bearings compared with sliding bearings. By examining their performance, maintenance requirements, durability, and cost-effectiveness, readers can gain a comprehensive understanding of which type best suits their specific applications. Whether you’re an engineer, manufacturer, or decision-maker in the machinery industry, this guide aims to provide valuable insights for optimizing your equipment choices.

Linear motion bearing/Sliding bearing

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

• The friction coefficient of rolling bearings is smaller than that of sliding bearings, and the transmission efficiency is high. The friction coefficient of general sliding bearings is 0.08-0.12, while the friction coefficient of rolling bearings is only 0.001-0.005. Due to their low friction and high precision, they are often used in motors, conveying systems and machine tools.

• Rolling bearings have been standardized, serialized and universalized, suitable for mass production and supply, and very convenient to use and repair.

• Rolling bearings are made of bearing steel and heat-treated. Therefore, rolling bearings not only have higher mechanical properties and longer service life, but also can save the more expensive non-ferrous metals used in the manufacture of sliding bearings, which is more cost-effective.

• The internal clearance of rolling bearings is very small, and the processing accuracy of each part is high, so the running accuracy is high. At the same time, the rigidity of the bearing can be increased by preloading, which is very important for precision machinery, such as the aerospace industry and the medical equipment industry.

• Some rolling bearings can bear radial loads and axial loads at the same time, so the structure of the bearing support can be simplified.

• Since rolling bearings have high transmission efficiency and low heat generation, they can reduce the consumption of lubricating oil and make lubrication and maintenance easier.

• Rolling bearings can be easily applied to shafts in any direction in space.

However, everything has two sides, and rolling bearings also have certain disadvantages compared with sliding bearings, which are mainly manifested in:

• The load-bearing capacity of rolling bearings is much smaller than that of sliding bearings of the same volume, so the radial size of rolling bearings is large. Therefore, sliding bearings are often used in occasions with large loads and occasions requiring small radial dimensions and compact structures. For example, they are used in heavy machinery such as excavators and cranes, which are extremely important for bearing durability and load-bearing capacity.

• Rolling bearings have large vibrations and noises, especially in the later stages of use. Therefore, rolling bearings are difficult to handle in occasions with high precision requirements and no vibration is allowed. Generally, sliding bearings are used for better results.

• Rolling bearings are particularly sensitive to foreign matter such as metal chips. Once foreign matter enters the bearing, large vibrations and noises will be generated intermittently. In addition, rolling bearings are also prone to early damage due to metal inclusions, etc. Even if there is no early damage, the life of rolling bearings is also shortened to a certain extent. In short, the life of rolling bearings is shorter than that of sliding bearings. Therefore, in the steel and mining industries, due to the harsh working environment, it is more appropriate to choose sliding bearings.

Conclusion

Compared with sliding bearings, each type of rolling bearing has unique advantages and can meet specific industry needs. Therefore, the two cannot completely replace each other, and each develops in a certain direction to expand its own field. However, due to the outstanding advantages of rolling bearings, there is a trend of latecomers catching up. At present, rolling bearings have developed into the main support type of machinery and are increasingly widely used.