The supporting forms of the slewing device of the stacker reclaimer are mainly trolley type, slewing bearing type, and tapered roller type, and slewing bearing is the most common one.The slewing ring bearing is simple and convenient to install, and the bearing itself can also withstand the overturning moment of the upper part. The shortcoming in the use of slewing bearings is that it is difficult to replace when a problem occurs. Therefore, many users choose better quality bearings when choosing slewing bearings to avoid and reduce the replacement of slewing bearings. Slewing bearings generally have a service life of at least 7 to 8 years, and good quality can reach more than 25 years.