Ultimate speed, required reliable life, bearing capacity and other factors have an important impact on bearing selection, structure, size, tolerance grade, working clearance and so on.

1. Selection of species.
Different types of rolling bearings have different characteristics and are suitable for different conditions of use of various machinery. When choosing a bearing, the following factors are usually taken into account. Generally speaking: when bearing thrust load, choose thrust bearing and angular contact bearing. For high-speed application occasions, more ball bearings are used. When bearing a larger radial load, choose roller bearings. In a word, the selection personnel should choose the right type from different manufacturers and a variety of bearing products.

2. Space and position occupied by bearings.
In machine tool design, the axis size is usually determined first, and then the rolling bearing is selected according to the axis diameter. Ball bearings generally choose small shaft, large shaft roller bearings. However, when the bearing is limited in the direction of the diameter of the machine, needle roller bearings, ultra-light and ultra-light series ball bearings or roller bearings can be selected; When the bearing is limited in the axial position of the machine, narrow series or extra-narrow series ball bearings or roller bearings can be selected.

3. The size, direction and performance of the load borne by the bearing.
Load is the primary factor in bearing selection. Rolling bearings are used to withstand heavy loads, ball bearings are used to withstand lighter or moderate loads, bearing made of carburized carbon steel or bainitic hardening that can withstand impact and vibration loads.
When subjected to pure radial load, deep groove ball bearings, cylindrical roller bearings or needle roller bearings can be selected. When the pure axial load is small, the thrust ball bearing can be selected. In the case of large pure axial load, thrust roller bearings can be selected. When bearing radial and axial combined loads, angular contact ball bearings or tapered roller bearings are generally selected.

4. Centering of bearings.
If the center line of the shaft is inconsistent with the center line of the bearing seat, there is an Angle error, or because the distance between the two bearings of the shaft is large, and the rigidity of the shaft is small, it is easy to be bent or tilted by force, you can choose self-aligning roller bearings and external ball bearings. If there is a slight tilt or bending of the shaft, such bearings can continue to work normally. The self-aligning performance of bearings with different coaxiality is related to their allowable axiality. The greater the value of different axiality, the better the self-aligning performance.