Reaserch On Static And Dynamic Characteristics Of Micro-hole Compensated Aerostatic Bearing

The aerostatic bearing has a simple structure,low pollution,and high accuracy.It has been applied in some mechanical fields that require high speed and high accuracy.The orifice compensation aerostatic bearing has high bearing capacity and rigidity,but the exist of the air cavity results in poor stability.To further improve the performance of aerostatic bearings.In this paper,a new type of micro-hole compensated aerostatic bearing is proposed based on the ordinary orifice compensated aerostatic bearing.The structure of the micro-hole restrictor is similar to that of the orifice restrictor.But the diameter of the orifice of the micro-hole restrictor is generally less than 0.1mm.Based on the basic theory of gas lubrication,the dynamic Reynolds equations are derived.For the second-order partial differential Reynolds equation,it is difficult to solve the problem.The weighted remainder method and the finite element method can be used to discretize and reduce the Reynolds equation.The solution flow chart of the formula of the discharge coefficient is designed,and the correctness of the solution method is verified.Considering the vortex of the rotor cylinder,the coordinate system of the aerostatic bearing system is established.The expression of the film thickness is derived when considering the roundness error.The rotor dynamic equation with mass eccentricity is derived.In combination with the dynamic Reynolds equation,the program for solving the rotor trajectory is written using Matlab software.In order to study the static characteristics of micro-hole aerostatic bearing.The static Reynolds equation is derived,designing the solution flow chart and using Matlab software to write a program for solving static characteristics of the aerostatic bearing.The influence of bearing structure parameters on bearing static characteristics was studied.By comparing the static characteristics of micro-hole aerostatic bearings with orifice compensated aerostatic bearings,it is found that the micro-hole aerostatic bearing has better static characteristics.Considering the roundness error,through simulation calculation,the rotor's trajectory map,spectrogram,Poincaré map and the bifurcation diagram are drawn to analyze the dynamic characteristics of the micro-hole aerostatic bearing.Studies have shown that compared with orifice compensated aerostatic bearings,micro-hole aerostatic bearing have better dynamic stability.An experimental platform was set up to test the static characteristics of the aerostatic bearing.Then the results of the test and the theoretical calculation are compared and analyzed.