Double-row ball slewing ring gear and swing bearing can carry axial load, tilting moment and radial loads at the same time. The top ball mainly carries the axial load and positive tilting moment. The drop ball takes the opposite tilting moment. This is the reason for the loading capacity of the double row ball slewing ring bearing being larger than the four-point contact ball slewing bearing; however, the frictional ratio is much larger. The double row ball slewing bearing consists of an inner ring, outer ring, balls in double rows, spacers, sealing device, and other components.

The double row slewing ring bearing is mainly for the working conditions when carrying an axial load, larger tilting moment, and where the mounting place is limited in radial direction.