Gem bearing slewing ring, is a kind of large bearings can withstand a comprehensive load, can withstand greater axial, radial load and overturning moment. Slewing ring bearings are generally equipped with mounting holes, internal or external gears, oil holes and sealing devices, thus enabling the host design compact structure, easy to guide, easy maintenance. Slewing bearing with toothless, external teeth and internal teeth of the four-point contact ball bearings, double row angular contact ball bearings cross cylindrical roller bearings, tapered roller bearings and three rows of cross-cylindrical roller bearings four Series, of which four-point contact ball bearings with high static load capacity, cross-cylindrical roller with high dynamic load capacity, cross-tapered roller bearing pre-interference can make the bearings have greater support rigidity and slewing accuracy, Three rows of cylindrical roller bearings due to the bearing capacity of the lead to the height of the various forces are different from the roller to withstand the same circumstances, the bearing diameter can be greatly reduced, so there is a more compact host features A high load bearing slewing ring. Slewing bearings are widely used on cranes, mining machinery, construction machinery, port machinery, marine equipment and high-precision radar machinery and missile launchers and other equipment on the large slewing device. At the same time can also be based on the user's specific requirements design, development, production of a variety of special structure slewing ring bearings