Characteristic Calculation And Experimental Research Of Aerostatic Bearing With Orifice Restrictors

Because of unique advantages of small friction loss,high running precision,low oil pollution,simple structure,long service time,Gas bearing rotor system has a broad application prospect in rotating machinery industry and opened a new era for the development of high speed power machinery equipment.In order to adapt to the demand of high performance parameters on the rotor bearing system,the rotor speed is increasing and the requirement of the bearing is also more and more strict,but the problems of shafting stabilitycaused by high speed is also increasing,so there are new challenges to the development of gas lubrication.Based on the development and application of high speed turbine expansion machine,this paper taking orifice compensated aerostatic bearing as the research object.Firstly,this paper has carried on the static characteristic calculation,and establishes the model.Then through the one-dimensional flow assumption,deduces the results of the pressure distribution and static load capacity and static stiffness.Using the latest Matlab programming software,the fast output calculation of bearing capacity check is realized and precision and efficiency ofcalculation is improved,so laid a foundation for steady state calculation and further study.According to the Reynolds equation for compressible gas,the steady state characteristics were calculated by using the finite element method.The basic principle of the finite element solution of the compressible Reynolds equation was introduced and the orifice compensated aerostatic bearings were calculated accurately.Then the gas pressure distribution was obtained and based on the pressure distribution,the bearing capacity and stiffness of the bearing was solved.Then the gas bearing eddy mechanism and the calculation method of vortex dynamics was expounded.The effect of dynamic pressure and the supply pressure was researched.Finally,for the experiment of high speed rotor system,test equipment and system are introduced in detail,the main functions and realization methods of each system was analyzed and the method of test was presented.Then the test results were analyzed in detai and through the pattern and amplitude frequency curve,the characteristics of low frequency eddy and low frequency oscillation was presented. Then combined with Yang Jinfu engineering stability criterion,the stability of rotor system are analyzed and experimental study on the effect of rotating speed and supply pressure was researched.In addition,the test results of orifice compensated hydrostatic gas bearings with slot line was also presented and provides the basis for the same test.