Basic knowledge of tapered roller bearing installation

Basic knowledge of tapered roller bearing installation
① Bearing positioning
In order to run smoothly, a shaft generally has at least two fulcrums for axial and radial support, and each fulcrum has at least one or more bearings. Generally, one bearing plays a positioning role, and the other bearing does not. In special cases, two bearings play a positioning role at the same time.
The positioning bearing provides radial support and axial guidance. Therefore, the locating bearing must be fixed on the shaft and the bearing housing at the same time. Deep groove ball bearings, spherical roller bearings, double-row angular contact ball bearings, and paired single-row angular contact ball bearings can all be used as positioning bearings. Paired tapered roller bearings can also be used. Cylindrical roller bearings without flanges can also be used as locating bearings when matched with thrust bearings with radial clearance.
Non-positioning bearings only provide radial support, and they must be movable in the axial direction. Axial movement can be generated by the bearing itself (for example, cylindrical roller bearing), or it can be the relative movement between the inner or outer ring of the bearing and its support.
Cross-positioning bearings can be composed of ball bearings or roller bearings that simultaneously bear axial load in at least one direction.
② Original clearance and remaining clearance of bearing
The axial and radial clearance of the bearing itself has been determined during machining (represented by C1/C2/C0/C3/C4/C5/). After installation, the remaining clearance of the bearing will be reduced. After the equipment starts to operate, the clearance will be further reduced with the rise of temperature, but it will always maintain a small positive value.
The best remaining clearance will guarantee the longest bearing life. Too large or too small clearance will affect the bearing life.
For cylindrical bore bearings, the residual clearance is determined by the fit size of the bearing and shaft (the larger the interference, the smaller the residual clearance). For tapered inner bore bearings, the remaining clearance is determined by the tightness of the installation (the tighter the installation, the smaller the remaining clearance).
For cylindrical bore bearings, the remaining clearance is mainly ensured by the matching of the bearing and its installation position, so the size of the installation position must be carefully measured before installation.
For tapered hole bearings, the remaining clearance is controlled by the installation tightness, so the relevant clearance control standards should be strictly observed during installation
③ Clean site and clean lubricating oil
The unclean site will cause foreign matters to enter the lubricating grease or bearing running parts, which will cause abnormal damage to the bearing. Under normal circumstances, the oil film between moving parts is only 0.1~1 micron, and the size of a dust particle is 10 times or more than it. These particles lead to stress concentration and early bearing damage.