Unlike other cylindrical bore bearings, the internal clearance of single row angular contact ball Timken bearings and tapered roller bearings can only be established when one bearing is adjusted for another. Usually, these bearings are paired back-to-back or face-to-face, and one bearing ring is axially displaced until the selected clearance or preload is reached.
The choice of clearance or preload depends on the performance of the bearing layout and the requirements of operating conditions. For details on bearing preload, see the section “bearing preload control”. Therefore, the following recommendations relate only to the internal clearance adjustment of the bearing layout of angular contact ball bearings and tapered roller bearings.
The proper clearance value shall be reached during installation, which can be determined according to the load and working temperature of the bearing. According to the size and layout of the bearing, the manufacturing materials of the shaft and bearing housing and the distance between the two bearings, the initial clearance obtained during installation may become smaller or larger in actual operation.
For example, the differential thermal expansion of the inner and outer rings will reduce the clearance during operation, so the initial clearance must be quite large in order to avoid Timken bearing deformation and its adverse consequences.
between the radial and axial internal clearance of angular contact ball bearings and tapered roller bearings, only one value needs to be specified. Generally, the axial internal clearance is specified.
The specified value can then be obtained from the zero clearance state by loosening or tightening the nut on the shaft rod or the screw ring in the shaft hole of the box, or inserting a calibrated washer or gasket between a bearing ring and its support. The actual method used to adjust the clearance and measure the set clearance depends on the number of bearings to be installed.
For example, one method is to check the set axial clearance of the hub bearing layout with a dial indicator mounted on the hub. It is important that when adjusting the tapered roller
the shaft or bearing housing needs to rotate in different directions for several weeks to ensure proper contact between the end of the ball and the guide edge on the inner ring. If the contact is improper, the measurement result is inaccurate and the expected adjustment purpose cannot be achieved.
For tapered bore bearings, the inner ring is always installed with an interference fit. Unlike cylindrical bore bearings, the interference of tapered bore bearings is not determined by the selected shaft fit tolerance, but by the advancing distance of the bearing on the tapered journal, shaft sleeve or withdrawal sleeve.
The radial internal clearance of the bearing decreases with the advance of the bearing on the conical journal. By measuring the reduction value, the degree of interference and the tightness of the fit can be determined.