There are many types of slew drive and rotary drive devices, and the following factors can be considered when choosing, so as to make a choice. 
1. Size, direction and nature of load: 
Slew Drive and Slew Bearing suitable for light load, roller bearing suitable for heavy load and impact load.
When the rolling bearing is subjected to pure axial load, the thrust bearing is generally selected. When the rolling bearings are subjected to pure radial load, deep groove ball bearings or short cylindrical roller bearings are generally selected.
When the slew drive by pure radial load at the same time, there is not much axial load, can choose deep groove ball bearings, angular contact ball bearings, tapered roller bearings and self-aligning ball or self-aligning roller bearings;
When the axial load is large, the angular contact ball bearing and tapered roller bearing with larger contact Angle can be selected, or the centripetal bearing and thrust bearing can be combined together, which is especially suitable when the axial load is very high or the axial rigidity is special.
 
2. Allowable speed: 
There are great differences due to different types of slew drive bearing.
In general, bearings with small friction and less heat are suitable for high speed. In design, rotary rolling bearings should be designed to work under the condition of lower than their limit speed. 
3. Rigidity: 
when the bearing of the slew drive device bears the load, the bearing ring and the contact place of the rolling body will produce elastic deformation. The amount of deformation is proportional to the load, and the ratio determines the size of the bearing rigidity. Generally, the rigidity of bearings can be improved by the pretightening of bearings.In addition, considering the combination and arrangement of bearings in the design of bearing supports can also improve the bearing stiffness. 
4. Self-aligning performance and installation error: 
after the bearing is loaded into the working position, the installation and positioning are often poor due to manufacturing error. This is often due to the shaft fishing and thermal expansion and other reasons, so that the bearing bears too much load, causing early damage. Self-aligning bearings can overcome defects caused by installation errors by themselves and are therefore suitable for this type of use. 
5. Installation and disassembly of rotary drive device: 
tapered roller bearings, needle roller bearings and tapered roller bearings, etc., belong to the type of bearings with inner and outer rings separable (namely the so-called separation type bearings), easy installation and disassembly.