Slewing ring bearings usually have diameters ranging from 0.2 to 10 meters. They are composed of mounting holes, inner or outer gear rings, lubricating oil holes and sealing devices. The mounting holes are divided into through holes and threaded holes. It is different for various industries. The slewing bearing has a variety of structural types to adapt to the use requirements, and can meet the needs of the main machine function with different manufacturing precision levels, so the slewing bearing is an indispensable machine component on the slewing device of medium and large construction machinery. part. It occupies a pivotal position in the machinery industry, construction industry, coal industry and shipbuilding industry.