The rolling bearing developed on the basis of sliding bearing, its working principle is to replace sliding friction with rolling friction. Generally, it is composed of two ferrules, a set of rolling elements and a cage. It is highly versatile, standardized and serialized. High mechanical base parts.

Since various machines have different working conditions, various 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 inner ring, outer ring, rolling elements and cage.

The roles of various parts in the bearing are:
For radial bearings, the inner ring usually fits tightly with the shaft and runs together with the shaft, and the outer ring usually forms a transitional fit with the bearing seat or mechanical housing hole to play a supporting role. However, in some cases, the outer ring is also running, the inner ring is fixed to support or both the inner ring and the outer ring are running at the same time.

For thrust bearings, the shaft ring that tightly fits and moves with the shaft is called the shaft ring, and the seat ring that forms a transitional fit with the bearing seat or mechanical housing hole and plays a supporting role. Rolling elements (steel balls, rollers or needles) in the bearing are usually evenly arranged between the two rings for rolling motion with the help of a cage. Its shape, size and quantity directly affect the load capacity and performance of the bearing. In addition to separating the rolling elements evenly, the cage can also guide the rotation of the rolling elements and improve the internal lubrication performance of the bearing.