Finite Element Analysis And Experimental Study On The Stability Of Precision Aerostatic Bearing Stage

As the rapid development in science and technology today, high speed and high precision equipment manufacturing technology has become a development trend, the aerostatic bearing stage meet requirements of high speed and high precision technology for the advantages of high precision, no friction, temperature rise small and long life time, so it is caused and researched widely. However, the bearing capacity of the small static flotation platform, low stiffness, poor stability of shortcomings limit the application of flotation platform for further promotion.There is a interdependent relationship between the aerostatic bearing stage of carrying capacity and stability, if unilateral pursue high carrying capacity and stiffness, it will affect its stability, so how to meet the stability of the cases, as far as possible improves the carrying capacity and stiffness is the main research direction of the aerostatic guide way. As the research object to the rectangular closed aerostatic guide way, the mainly studied as followed:1,Established the whole parameters of 3D fluid model of the aerostatic bearing stage and analyzed, according to the gas membrane pressure distribution, the aerostatic bearing stage is simplified into three thrust bearing. And then as the research object to the thrust bearings, a gas film of creation pressure groove is analyzed, the homogenizing effect of film pressure with the pressure groove is studied, then the influence factor of carrying capacity and stiffness with the Pressure-equalizing groove width and depth are analyzed.2,Based on the D.D.Fuller the gas bearing stability theoretical, the equation of air hammer self-excited is obtained through the theory and numerical simulation with Matlab, the regulation of various structural parameters leading the self-excited air hammer is analyzed.3,The reason of generating micro vibrations is analyzed, and the gas velocity of film in different regions are obtained, again according to the structural parameters calculated the critical speed of creating turbulent flow, compared the simulation velocity it can determine where the micro vibration happened. The regulations of generating micro vibrations with very factors are analyzed, and then put forward the corresponding method of micro vibrations suppression.4,According to the theory of the above about stability and influence factors, the vibration test system (LMS) is used to test the stability of aerostatic guide way, through the experimental method the regulations of generating the air hammer and the micro vibration are studied, the result prove that the theoretical analysis is effective.5,According to the theory research and experiment results, comprehensive balance the requirement of the aerostatic bearing stage stability and carrying capacity, structural optimization is designed.