Bearing life. When mounted rolling bearings are installed in machinery and equipment for operation, even under suitable conditions, after a certain period of time, the mounted bearings may experience increased vibration, noise, and burns. Due to such reasons, the time that the seated rolling bearing cannot continue to be used is called the life of the seated bearing. The life of a seated rolling bearing includes two types that cannot be used due to fatigue of the bearing material (fatigue life) and cannot be used due to poor lubrication due to deterioration of grease. It can be calculated as the rated life of the bearing and the life of the grease. The life of a seated rolling bearing is determined by the shorter of the rated life of the bearing and the life of the grease. However, the seated rolling bearing adopts the oil supply type, so the grease life can be extended to the rated life of the bearing by proper oil supply. When a seated bearing is used in the non-lubricating mode, its life is the shorter of the rated life of the bearing and the life of the grease. However, when rolling bearing with housing is installed in a machine or device for operation, it may be unable to continue to be used due to factors other than the rated life of the bearing or grease life (wear, indentation, fracture, burns, etc.). . These can be avoided by fully considering the selection, use, installation, and lubrication of rolling bearings with seat. Basic rating life and basic load rating: When the bearing rotates under load, the raceway surface of the inner and outer rings and the rolling surface of the rolling elements are constantly subjected to alternating loads. Even if the conditions of use are normal, the raceway surface or the Scale-like damage (called peeling or flaking) appears on the rolling surface. The total number of revolutions before this damage occurs is called the (fatigue) life of the bearing. Even if the structure, size, material, processing method, etc. of the bearing are exactly the same and rotate under the same conditions, there will still be a big difference in the (fatigue) life of the bearing. Therefore, it is stipulated that when a batch of the same bearings are rotated under the same conditions, the total number of revolutions at which 90% of the bearings do not have rolling fatigue damage is called the basic rating life of the bearing (that is, the life of 90% reliability). The basic load rating reflects the bearing’s ability to withstand rolling fatigue (i.e. load capacity). It refers to a pure radial load (for radial bearings) or a central axial load (for thrust bearings) of a certain size and direction. When the outer ring is stationary (or the inner ring is stationary while the outer ring is rotating), the basic rating life under this load can reach 1 million revolutions. The above loads are respectively referred to as the radial basic dynamic load rating (Cr) or the axial basic dynamic load rating (Ca). The ball bearing for rolling bearing with seat is expressed by the basic radial dynamic load rating (Cr), and its value is shown in the bearing size table.