Slewing bearings are a kind of big supporting bearings which can carry integrated load, and can also carry heavy radial load, axial load, and tilting moment. This type of bearings usually bring with open holes, internal wheels or outer rotor, lubricating holes and gland bush. They have the characristic of compact conformation, slightness, strongness, smoothness of operating, high precision, safe and reliable. They can be widely used in engineering, metaling, mining, oil, chemical, light industry, aviation, port, vessel, war industry, and instruments and meters.