Experimental Study On Static And Dynamic Performance Of Aerostatic Thrust Bearing With Elastic Thin Plate

Aerostatic bearing is a kind of moving parts with high-pressure air as working medium,It can achieve high-precision,low friction motion,so it has been widely used in some processing equipment and measuring instruments that need high-precision motion.In these precision equipment,the external vibration and its own vibration are the main factors affecting its motion accuracy,and aerostatic bearing is the main part of these precision equipment to bear the motion load,it is more necessary to study its working condition under the vibration state.Therefore,in order to study the actual operating characteristics of aerostatic bearings,this paper takes a new type of aerostatic bearings as the object,and studies the actual operating characteristics of aerostatic bearings by means of experimental.In order to study the static and dynamic performance of bearings by means of experiments,firstly,this paper summarizes the theoretical and experimental research status of the performance of aerostatic bearings at home and abroad;based on the existing research results,the principle scheme of static and dynamic test of bearings is proposed,and the test scheme is selected;In the static performance test,the static load is applied by the cylinder,and the static load-bearing performance and stiffness of the bearing were measured.In the dynamic test,the exciter is used as the external vibration source,and the film clearance and dynamic load changes of the bearing under the vibration state wer measured.Secondly,based on the above testing principles,a test bench is designed to test the static and dynamic performance of aerostatic bearing,and the mechanical system and test control system of the test bench were installed and debugged.In order to verify the reliability of the test bench,preliminary test was carried out.The test results show that the designed test bench can meet the requirements of the test experiment.In order to improve the manufacturing technology of aerostatic thrust bearing with elastic sheet.In this paper,vacuum brazing method is used to carry out welding experiments on the bearing body of aluminum alloy material and the stainless elastic sheet,the relevant parameters of welding were selected,and welding process experiments were carried out.Secondly,due to the existence of elastic pressure equalizing groove on the surface of elastic thin plate bearing,the bearing support surface is machined by rotary grinding device and plane grinding machine by means of ventilation grinding,and the flatness of the bearing surface was measured.The results show that the flatness of the bearing surface meets the requirements of experimental testing.Based on the test bench,the aerostatic thrust bearing with elastic thin plate is taken as the experimental object;in static performance experiment,the experimental method is given,and the static load-bearing experiment comparison of rigid equalizing groove aerostatic bearing and elastic thin plate aerostatic bearing with the same structural parameters.The results show that the load-carrying capacity of elastic thin-plate aerostatic bearings is lower than that of rigid groove bearings,but the stiffness of elastic thin-plate aerostatic bearings is greater than that of traditional rigid groove bearings in a certain film gap.In the aspect of dynamic performance experiment,sinusoidal excitation is used as the external excitation source.The experimental data are collected by the test system,and the external vibration of the bearing at different frequencies is tested by the test.The data collected by the test system are analyzed by the least square method,and the dynamic characteristic coefficients of the aerostatic bearing are obtained.The results show that under the same dynamic load amplitude,with the increase of dynamic load frequency,the dynamic stiffness of the bearing increases gradually,and the damping coefficient of the bearing decreases gradually.Secondly,the dynamic characteristics of the bearing under different working conditions are tested.