Design And Analysis Of An Ultra-precision Rotary Table With A High Diameter-length Ratio

Ultra-precision hydrostatic rotary tables are widely used in ultra-precisionmachines to place workpieces or other axis. The kinematic accuracies of the rotarytable play important roles in the manufacturing accuracies of the whole machine.Hydrostatic bearings’ stiffness and other performance evaluation mainly influence thekinematic accuracies of the rotary table. Meantime, the structure scheme of the rotaryplate defines difficulties and possibilities in manufacturing and assembling. Therefore,do research on design and analysis of hydrostatic bearings in ultra-precision rotarytable is very valuable.This essay is based on design and manufacturing of ultra-precision rotary tablewhich applied in “Advanced CNC machine tools and basic manufacturing equipment”PRC’s significant technique project. The rotary table will be placed on an liner axishorizontally, so it should be a high diameter-length ratio rotary plate. For this purpose,the structure scheme is quite different from the former structures. So, this structurescheme will provide supply for the future designs of high diameter-length ratio rotaryplates.This paper completed the design and calculates for hydrostatic bearings in therotary plate. During this period, this paper composed two programs which helped toreduce work-load. After getting the proper sizes of hydrostatic bearings, this paperstarted to design for other parts of the rotary table.The transformation of transverse bearing and thrust bearing was analyzed withANSYS Mechanical APDL in the condition of oil pressure works on some location onthe bearings. Then, I checked the stiffness parameters with the structure transformationand temperature increase of oil in the bearings to see whether they meet therequirements.This paper completed the fluid-structure interaction analysis to get the bearings’structure transformation that closer to the real working situation. Then, re-calculate thestiffness parameters.Spring elements were set to take the place of the oil firm supports of thehydrostatic bearings. Stiffness parameters of the spring elements were evaluated as thestiffness parameters of the bearings. Then, the dynamic analysis of rotating part of therotary table was preceeded and got the amplitude frequency characteristics of the rotatesystem under the grinding force.