The rotary table is widely used on various CNC milling machines, boring machines, various vertical turning, vertical milling and other machine tools. The rotary table needs to bear the weight of the workpiece well, but also needs to ensure its rotation accuracy under load. The turntable bearing, as the core component of the rotary table, must not only have a high load-bearing capacity during the operation of the turntable, but also have high rotation accuracy, high anti-overturning ability, and high speed capability. In the design of the rotary table, the more widely used bearing types are roughly divided into the following types:

1. Thrust ball bearing + cylindrical roller bearing

Thrust ball bearing can bear a certain axial force, so the bearing is mainly used to bear the weight of the workpiece; Cylindrical roller bearings are mainly used for radial positioning and bearing external radial forces (such as cutting force, milling force, etc.) The thrust ball is a point-contact bearing, its axial bearing capacity is relatively limited, so it is mainly used in small or medium-sized machine tool rotary tables.

2. Hydrostatic bearing + precision cylindrical roller bearing

Hydrostatic bearing is a kind of sliding bearing that relies on external supply of pressure oil and establishes a static pressure bearing oil film in the bearing to achieve liquid lubrication. The hydrostatic bearing always works under liquid lubrication from start to stop, so there is no wear, long service life, and low starting power. The hydrostatic bearing also has the advantages of high rotation accuracy, high oil film rigidity, and can inhibit oil film oscillation.

Precision cylindrical roller bearings have good radial bearing capacity, and due to the use of precision bearings, the rotation accuracy of the rotary table can also be well guaranteed. The rotary table of this kind of design can withstand high axial forces. Some workpieces weigh more than 200 tons, and the diameter of the turntable exceeds 10 meters.　　

3. Cross roller bearing

The application of crossed roller bearings on turntables is also relatively common. The characteristic of crossed roller bearings is that there are two raceways in the bearing and two rows of rollers arranged in a cross. Compared with the traditional thrust bearing and radial centering bearing combination, the crossed roller bearing has a compact structure, a small volume, and simplifies the design of the worktable, thereby reducing the cost of the turntable.