The LYAB  three row cylindrical roller combined slewing bearing can carry axial load, tilting moment, and radial load all at the same time. Compared to cross-cylindrical roller slewing bearing the load of each roller is reduced. Point contact is changed into line contact compared with that of a double row ball slewing bearing, the contact stresses are also decreased. Therefore, the load capacity of this design of slewing bearing is the highest under the conditions of a bearing with the same boundary dimensions. Axial load and radial load for this design are loaded by different rollers, in which the axial load and tilting moment are loaded by two groups of horizontal placed rollers, the radial load is loaded by one group of vertical placed rollers. The LYAB three row cylindrical roller combined slewing bearing mainly consists of the components such as inner ring, outer ring, three rows of rollers, cage (spacing blocks), a seal device etc. This slewing bearing design is suitable for most applications where a large axial load and tilting moment, or with a larger radial load, or with a low requirement for friction moment.