What are the three allowable for bearing installation and disassembly

The fit between bearing and shaft is generally transition fit, and the fit between seat ring and bearing seat hole is generally clearance fit. The middle shaft ring of two-way bearing shall be fixed on the shaft to prevent rolling relative to the shaft. If it is installed reversely, not only the bearing does not work normally, but also the mating surfaces will be severely worn. When the box shell hole is deep, the extended dial indicator can also be used for maintenance. Generally, the installation method of bearing is mostly shaft rotation, so the fit between inner ring and shaft is win-win fit, and the fit between bearing outer ring and bearing chamber is clearance fit.

In addition, a clearance of 0.2-0.5mm shall be reserved between the bearing race and the bearing seat hole to compensate for the error caused by inaccurate processing and installation of parts. When the center of the bearing ring is offset during operation, this clearance can ensure its automatic adjustment, avoid contact friction and make it run normally. When the bearing is installed accurately, its seat ring can automatically adapt to the movement of the moving bullet body to ensure that the moving bullet body is located in the raceway of the upper and lower rings. When installing SKF bearings, check the verticality of the shaft ring and the shaft center line. Otherwise, the bearing will be severely damaged. The method is to fix the dial indicator on the end face of the box shell so that the contact of the dial indicator is against the raceway of the bearing shaft ring. While rolling the bearing, observe the pointer of the dial indicator. If the pointer deviates, it indicates that the shaft ring is not perpendicular to the central line of the shaft.

The selection of specifications, dimensions and accuracy according to the service parts, service conditions and environmental conditions, and the matching of appropriate bearings are the premise to ensure the service life and reliability of bearings.

1. Allowable speed: under the condition of correct installation and good lubrication, the allowable speed is 0.3-0.5 times of the bearing limit speed. Under normal conditions, 0.2 times of the limit speed is the best.

2. Allowable inclination angle: tapered roller bearings generally do not allow the shaft to tilt relative to the housing hole. If there is inclination, the maximum shall not exceed 2 '.

3. Allowable temperature: under the condition of normal load, high temperature resistance of lubricant and sufficient lubrication, the general SKF Bearing is allowed to work at the ambient temperature of - 30 ℃ - 150 ℃.