Turntable bearings are large bearings with a special structure that can simultaneously withstand axial, radial loads, and overturning moments, integrating support, rotation, transmission, and fixation functions into one. Their basic structure consists of an inner ring, outer ring, rolling elements, and separator blocks. The core components adopt a slewing bearing design, commonly classified into single-row four-point contact ball type, double-row ball type, cross roller type, and triple-row roller type, among others. They are suitable for applications in construction machinery, wind power equipment, port machinery, medical devices, and other fieldsThe bearing rings are primarily made of surface-hardened steels such as 50Mn or 42CrMo, while the rolling elements are selected from GCr15SiMn bearing steel, offering high strength and wear resistance. During installation, it is essential to ensure the strength of the support components, adjust the tempered soft band to the non-load zone, and tighten the bolts according to standard specifications. Lubrication is mainly achieved through grease, and the sealing structure employs rubber or labyrinth designs . Domestic slewing bearings have achieved ultra-large-scale manufacturing with diameters reaching up to 15 meters. Through technological advancements such as split structures and floating guide systems, these bearings are now applied in heavy-duty equipment like cranes on offshore wind installation vessels
