Bearing support structure
1, both ends of the fixed support
The fixed support at both ends is a support form in which the two support ends each restrict the axial displacement in one direction. The characteristics and application of this support form are shown in the following table.
Bearing support structure
2, fixed - swimming support
The fixed-fixed support of the floating support means that the position of the bearing and the shaft and the housing hole are fixed at one of the bearing ends of the shaft so as to realize the axial positioning of the shaft in the direction; the floating bearing means at the other end, the bearing The relative movement between the shaft and the housing can be compensated for changes in the length of the shaft due to thermal deformation or manufacturing installation errors.
In this kind of support structure, the axial positioning accuracy depends mainly on the amount of axial clearance of the fixed end bearing, so when the fixed end uses a pair of angular contact ball bearings or tapered roller bearings, it uses a pair of deep groove balls. The precision of the bearing is high. In general, fixed-end bearings are available in three ways:
1) Deep radial ball bearings are available when subjected to radial loads and certain axial loads.
2) When subjected to radial load and two-way axial load, a pair of angular contact ball bearings or tapered roller bearings can be selected.
3) When radial loads and axial loads are separately applied, radial bearings and thrust bearings may be combined, or different types of angular contact bearings may be combined.
At this time, the inner and outer rings of the fixed-end bearing must be axially positioned and fixed with the shaft and the housing hole, respectively.
For the bearing selection of the moving end, the most convenient method is to use a cylindrical roller bearing with no inner ring or outer ring without ribs. If other types of bearings are used, a clearance fit between the inner ring and the shaft or the outer ring and the housing hole is required according to the load form and working condition, so as to achieve the requirement of axial movement.
3、Robary bearing at both ends
In some special occasions, if axial automatic adjustment is needed to compensate for the uneven wear and tear caused by machining or installation, the support structure with swimming at both ends can be adopted. In this kind of support structure, the bearings of both bearing ends do not make accurate axial positioning of the shaft, and they all belong to the floating bearing.
The angular contact ball bearings are not suitable for floating support in the two-way floating support. Other bearings that do not require adjustment can be used almost as swimming support.
Since the axially supported position of the shaft does not need to be accurately defined by the floating support at both ends, it is not necessary to adjust the axial clearance of the bearing during installation. During operation, even if the bearing is in an unfavorable state of heat, it will not be stuck.