Research On Motion Error Of Ultra-precision Hydrostatic Rotary Table Based On New Needle Gauge Restrictor

The ultra-precision hydrostatic rotary table occupies an important position in the field of precision machine tool processing,so it is required to have a high processing accuracy.In the actual working process of the hydrostatic rotary table,the rotary table is deflected due to a certain eccentric load,which affects the rotary accuracy of the rotary table.Therefore,it is necessary to study the dynamic and static motion characteristics of the rotary table and analyze the static Factors influencing the precision of the rotary table.This article first proposes to select and design the overall structure of the small ultra-precision static pressure rotary table,and designs an adjustable rotary loading device,which can realize the static pressure rotary work under the condition of reducing the structure disassembly Loading at any eccentric position of the table improves the stability of the static pressure rotary table under loading and the reliability of the rotary accuracy.It provides an experimental basis for the subsequent study of eccentric load.Secondly,the throttle as a throttle pressure regulating element of the static pressure turntable,its throttle accuracy directly affects the movement characteristics of the turntable.In this paper,the shape and position tolerance of the throttle is studied by using the Monte Carlo method.The results show that the diameter tolerance of the throttle has the most significant influence on the throttle gap,and reducing the diameter tolerance is beneficial to improve the throttle accuracy.Therefore,the simple structure of the needle gauge restrictor is used to experiment the influence of the diameter tolerance of the restrictor on the throttle accuracy.The influence of the restrictor processing and installation errors on the pressure of the oil chamber of the turntable is considered.The static pressure rotary table is quantitatively debugged to keep the pressure of the oil chamber stable,thereby improving the stability of the static pressure rotary table.In this paper,by analyzing the influence of the verticality error between the rotation axis of the static pressure rotary table and the upper and lower working surfaces of the rotary table on the axial rotation accuracy of the rotary table,the axial rotation error model of the rotary table is established,and the axial direction of the rotary table is analyzed.The formation mechanism of the rotation error increases the thickness of the oil film and the supply pressure appropriately,and effectively reduces the rotation error of the static pressure rotary table.Moreover,the direction of the perpendicularity error between the upper and lower thrust surfaces and the axis should be opposite,which is more conducive to the improvement of the rotary accuracy of the static pressure turntable.However,when subjected to heavy loads,the two perpendicularity errors are in the same direction,which can reduce the effect of external loads on the axial rotation error.Finally,build an experimental platform,verify the influencing factors of the axial rotation error of the static pressure rotary table and separate the measurement data to obtain the experimental results closer to the actual value.That increases with the increase of speed and eccentric load.