Bearing has a vital and irreplaceable role in mechanical design, and its scope is very wide, it can be understood that there is no bearing, the shaft is a simple iron bar. The following is a basic introduction to the working principle of the bearing. Bearings based on the development of rolling bearings, its working principle is rolling friction instead of sliding friction, generally composed of two rings, a group of rolling elements and a cage composed of strong versatility, standardization, high degree of serialization of mechanical basic parts. Due to the different working conditions of various machines, different requirements are put forward for rolling bearings in terms of load capacity, structure and performance. For this reason, rolling bearings need to have a variety of structures. However, the most basic structure is composed of an inner ring, an outer ring, a rolling element and a cage - often referred to as the four large pieces.

For sealed bearings, plus lubricants and sealing rings (or dust caps) - also known as six pieces. Various bearing type names are mostly named according to the name of the rolling element. The roles of various parts in bearings are: for radial bearings, the inner ring is usually tightly matched with the shaft and runs with the shaft, and the outer ring is usually transitional matched with the bearing seat or the mechanical housing hole to play a supporting role. However, in some cases, there is also an outer ring operation, and the inner ring is fixed to play a supporting role or the inner ring and the outer ring are running at the same time.

For thrust bearings, the shaft ring is closely matched with the shaft and moves together, and the bearing seat or the mechanical housing hole is transitionally matched and plays a supporting role. The rolling element (steel ball, roller or needle roller) is usually evenly arranged between the two rings in the bearing with the help of the cage for rolling movement, and its shape, size and number directly affect the load capacity and performance of the bearing. The cage can not only separate the rolling element evenly, but also guide the rotation of the rolling element and improve the internal lubrication performance of the bearing.

There are many kinds of bearings, and the role is not the same, but the working principle of the bearings changes, which is roughly described above.