Performance Study Of Aerostatic Bearings With Arrayed Microhole Restrictors

Aerostatic bearings have been widely used in the field of subtle process and precisionmeasurement technology because of their substantially high-precision and low friction,and they have become one of the most important basic component of ultra-precisionmechanisms. As the requirement on the moving and positioning accuracy becomes higherand higher, micro-vibration of aerostatic bearing has become the bottleneck to furtherdevelop the use of aerostatic bearings. In order to reduce the micro-vibration and ensurethe positioning accuracy of ultra-precision motion platform, this thesis mainly conductedthe following research.Firstly, a new type of restrictor—arrayed microhole restrictor was established basedon the gas-lubricated theory and air vortex theory. The purpose of this restrictor was tomaintain the load carrying capacity and stiffness and at the same time to reduce theamount of micro-vibration.Secondly, the FLUENT solver was used to simulate the flow field of aerostaticbearing with different restrictors and acquired the load carrying capacity, stiffness and theamount of micro-vibration under the same working conditions.Finally, the aerostatic bearing test platform was established to verify the simulationresults. The static load test procedure was designed using LabVIEW and NI hardware. Theexperimental value of static load carrying capacity and stiffness were acquired. Besides,the characteristics of micro-vibration were measured using LMS test system.Through numerical simulation of the flow field in aerostatic bearings with differentrestrictors and experimental measurement of micro-vibration of the bearing, the followingconclusions were drawn:(1) As the total air inlet area of arrayed microhole restrictors and the single holerestrictor are the same, employment of arrayed microhole restrictors maintained the load carrying capacity and the stiffness of aerostatic bearings (error less than10%);(2) Under the same working conditions, employment of arrayed microhole restrictorscan effectively reduce the micro-vibration of aerostatic bearings (a drop of50%).