Rotary tables are often used to fix and support work-pieces in machine tools. Because the deformation of the rotary table is known to significantly affect the precision in the work of the machine tool, it is very important to accurately predict the static displacements of the rotary table subjected to internal and external loads. This paper deals with modeling and experimental verification of the static displacements of a large-size rotary table supported by a thrust cylindrical roller bearing (T-CRB) and a double row cylindrical roller bearing (D-CRB). To this end, a rotary table model was developed along with the quasi-static models for T-CRB and D-CRB. The equilibrium equation of the rotary table was derived, and solved one by one in the looping manner, to overcome its statically indeterminate characteristics. The proposed modeling method was verified by means of comparing to the experimental results. Finally, an extensive simulation was carried out to investigate the deflection of the rotary table subjected to cutting forces.

The large volume multi-tasking vertical lathe was developed for machining the bearing parts for a wind power generator. Although the machined part is large in size high precision tolerances are required recently. One of the most important components to achieve this mission is the rotating table which holds and supports the part to be machined. The oil hydrostatic bearing is adopted for the thrust bearing and the rolling bearing for the radial bearing. In this article experimental performance evaluation and its analysis results are presented. The rotational accuracy of the table is assessed and the frequency domain analysis for the structural loop is performed. And in order to evaluate the structural characteristic of table the moment load experiment is performed. The rotational error motion is measured as below 10 μm for the radial and axial direction and 22,800 Nm/arcsec of moment stiffness is achieved for the rotary table.