Selection of roller bearing type

When selecting bearings, the main considerations are as follows:

Load of bearing

The magnitude, direction and nature of the load on the bearing are the main factors in selecting the bearing.

When selecting bearings according to the size of the load, compared with the point contact of ball bearings, the main components of roller bearings are in line contact, which is easy to bear the load, and the deformation after bearing is also small.

When selecting bearings according to the load direction, thrust bearings are generally selected for pure axial loads. Choose thrust roller bearing for larger axial force. Select thrust ball bearing for smaller axial force. For pure radial load, deep groove ball bearings, cylindrical roller bearings or needle roller bearings are generally selected. When bearing radial load and small axial load, deep groove ball bearing or tapered roller bearing can be selected; When the axial load is large, angular contact ball bearings or tapered roller bearings with large contact angle can be selected.

Speed of bearing

Generally, the speed will not have any impact on the selection of bearing type, but when the speed is large, the speed should be included in the standard of bearing selection.

(1) Compared with roller bearings, ball bearings have a higher limit speed, so in the case of high speed, ball bearings are preferred.

(2) With the same inner diameter, the smaller the outer diameter is, the smaller the rolling element is, so the centrifugal force added by the rolling element on the outer ring is smaller, so it is more suitable to work at high speed. According to its nature, needle roller bearings are more suitable for working at high speeds.

Self aligning performance of bearing

When the center line of the shaft does not coincide with the center line of the bearing seat and there is an angle error, or when the shaft is bent or tilted due to force, the axis of the inner and outer rings of the bearing will be deflected. At this time, a self-aligning bearing with certain self-aligning performance or an outer spherical ball bearing with a seat should be used.

Roller bearings are the most sensitive to the deflection of bearings, and the bearing capacity of such bearings may be lower than that of ball bearings in the state of deflection. Therefore, when the shaft stiffness and the support stiffness of the bearing seat hole are low, or when there is a large deflection moment, this kind of bearing should be avoided as far as possible.

Bearing installation and disassembly

When the bearing seat has no split surface and the parts must be installed and disassembled along the axial direction, the bearings with separable inner and outer rings (such as N0000, na0000, 30000, etc.) should be preferred.