Slewing bearing also called rotation supporting is a king of large-scale bearing can withstand the synthesis load. It can simultaneously withstand bigger axial, radial load and the overturning moment .The slewing bearing usually consists of bolt holes ,the internal or external gear ,the oil passage and sealing device .This kind of design makes the matching structure compact tightly ,guide simply ,and maintenance easily . The PRS slewing bearing has four series. There are four-point contact ball bearing (no-gear, outside gear ,inside gear ) ,double row angular contact ball bearing ,crossed cylindrical and tapered roller bearing and three-row cylindrical combined roller bearing .The four-point contact ball bearing has highest static load capacity .The crossed cylindrical roller bearing has highest dynamic load capacity .The pre-interference of the crossed tapered roller bearing makes it sustain highest stiffness and rotating precision. Three-row cylindrical combined roller bearing leads to bearing height because of the increasing loading capacity. The different raceways sustain relative forces. Therefore, at the same circumstance, the bearing diameter can largely reduced .This feature makes the matching structure became more compact. So we say it is a high sustaining capacity of slewing bearing. They can be widely used in the large-scale rotating devices of the hoisting machinery, excavate machinery, building machinery, harbor machinery, shipping machinery exactly accuracy radar machinery and missile launcher equipment ,and so on . We also have the capable of designing, developing and manufacturing special slewing bearing according to the customers’ specific requirements.