Preloading methods are divided into radial preloading and axial preloading two broad categories are as follows. 1, the radial preload method: Radial top and more used in radial load bearing tapered bore, the typical example is double row precision short cylindrical roller bearings, the use of nuts to adjust the bearing relative to the tapered shaft The axial position of the neck, so that the inner ring with a proper amount of expansion to obtain negative radial clearance, this method is mostly used in machine tool spindles and jet engines. 2, axial preload method: axial preloading method can be divided into two kinds of preload and preload. In the positioning preload, by adjusting the size of the bushing or gasket to obtain the appropriate preload; also by measuring or controlling the starting friction torque to adjust the appropriate preload; can also be used directly pre-adjusted preload Pairs of double bearings to achieve the purpose of preloading, then generally do not need to adjust the user again, in short, any axial preload bearing, the relative position of the use of certain will not change. Preload preload is the use of coil springs, disc springs, etc. to get the appropriate bearing preload method. The rigidity of the preloaded spring is generally much less than the rigidity of the bearing, so the relative position of the preloaded preloaded bearing will vary during use, but the preload will be approximately the same. The comparison between pre-tensioning and pre-stressing pre-tensioning is as follows: (1) When pre-tensioning is equal, the effect of pre-tensioning on the increase of bearing rigidity is larger, and the influence of rigid variation on bearing load during pre-tensioning is also much smaller . (2) positioning preload in use, due to the shaft and bearing temperature difference caused by axial length difference between the inner and outer ring caused by the temperature difference between the amount of radial expansion and displacement caused by the load, etc., will preload The amount of change; and constant pressure in the use of pre-stress changes are negligible.
