Optimal Design And Experiment Based On Fluid-structure Interaction Method For Stiffness Of Gas Bearing

Due to aerostatic bearings have more than the advantages of well-adapted to theenvironment and high working accuracy, so widely used in all kinds of theultra-precision processing occasions. The static characteristic is an important indicatorof bearing design process, under the actual condition when the bearing parts work, thegas-film’s pressure field will lead to deformation of the bearing structure, which willchange the static characteristic curve of the bearing and can affect the machingprecision of workpiece. Consequently, studying the changing rule and dynamic effect ofthe aerostatic bearing’s static characteristic under the state of fluid-structure interactionhas very important significance for promoting the ultra-precision maching performanceeffectively.This paper put the circular disk aerostatic thrust bearing as a main object of study,first the theory calculation formula of bearing’s static characteristic is presentedaccording to the existing research results and on the basis of having a simulation byusing FLUENT software to get the curve of loading capacity and static stiffness’schanging rule for bearing;Secondly by using the separating FSI method of combining the FLUENT withANSYS Mechanical under the Workbench14.0platform to have a simulation ofone-way and two-way FSI, obtain the distribution of gas-film’s fluid field and thedeformation in radial direction and circumferential direction for thrust plane; Bycompared the precision between two FSI methods, selected two-way FSI method as amain method of research and on the basis of resolving to obtain the curve of changingrule of bearing’s static characteristic by considering the deformation of structure;Finally with the analysis of bearing’s FSI model when the spindle is rotating, we canget the dynamic effect produced by the maching precision of workpiece due tomaldistribution of pressure inside the bearing and the manufacture errors of orifice, andhave an optimization of selection for orifice numbers From the perspective of reducingthis dynamic effect; we can have an analysis of structural dynamics for all bearing-partby loading the spring element equivalent to the bearing’s static stiffness and produce amethod of selection for thickness of thrust plane From the perspective of avoiding theresonance; Bearing’s static stiffness and deformation of thrust plane is measured withthe experient.