Slewing ring bearings are large-sized bearings with compositive larege loads carrying capability, which can accommodate asxial load, radial load and tilting torque simultaneously. These bearings normally have mounting holes, internal gears or external gears, lubricating holes and sealing installations. They are featured by compact configuration, light weight, good rigidity, smoothly running, high precision and reliable safety. Applications of the bearings are found in the industries such as engineering/project, metallurgy, mining, oil, chemistry, light industry, aviation, harbor/quay, vessels, military industry, instruments and meters etc.Our slewing bearing according different requirement has different configuration: single-row four point contact ball slewing ring bearing, double-row angular contact thrust ball slewing ring beairng, cross cylindrical roller bearings, cross tapered roller bearings and three-row cylindrical combination slewing ring bearing. These bearings also can be divided according to whether have gear and distribution of the gear: no gear, external gear and internal gear.