The size, direction and properties of the load bearing. Such as the size of the load, whether there is only radial load, axial load is unidirectional or bidirectional, the degree of vibration or impact, and so on. After considering these factors, the most suitable bearing structure type is selected. Generally speaking, the radial load of bearings with the same inner diameter varies according to the series.

The type of bearing that the rotating speed can adapt to the mechanical speed. The limit speed of bearing depends not only on bearing type, but also on bearing size, cage type, precision grade, load condition and lubrication mode. Therefore, these factors must be taken into account in the selection. The inner diameter of the bearing with the same structure 50~100mm has the highest limit speed, and the rotation accuracy has the type of bearing with the desired rotation accuracy.

According to the ratio of rotating speed to limit speed, the accuracy of bearing is determined. The higher the accuracy, the higher the limit speed, the smaller the heating, which exceeds 70% of the limit speed of the bearing. The precision grade 2 of the bearing must be improved, the higher the dimensional accuracy is, the less the influence on the original clearance will be after matching with the shaft, and the smaller the heating under the same radial original clearance.

Relative tilt analysis of inner ring and outer ring. The factors that cause the relative tilt of the inner ring and the outer ring of the bearing (such as the deflection of the shaft caused by the load, the poor accuracy of the shaft and shell or the installation error), and the type of bearing that can adapt to this use condition. If the relative tilt of the inner ring and the outer ring is too large, the bearing will be damaged by the internal load. Therefore, the centring roller bearing which can withstand this tilt should be selected. If the tilt is small, other types of bearings can be selected.