The Direct-Coupling Method for Analyzing the Performance of Aerostatic Bearings Considering the Fluid–Structure Interaction Effect

Abstract

In the interest of analyzing the effect of the structural deformation root caused by gas pressure on the static features of aerostatic bearings, a fluid–structure interaction (FSI) model based on orifice-type aerostatic bearings is proposed that can predict the characteristics of aerostatic bearings more accurately by using the direct-coupling method (DCM). By using COMSOL Multiphysics, the governing equation matrix of the finite element model of structural deformation and gas film pressure was solved with the integral solution method, and the orifice boundary conditions were calculated with the root iteration method. At the same time, the static performance of I-shaped orifice-type aerostatic bearing with various supply pressures was analyzed theoretically and tested experimentally. The results show that in comparison with the calculation results without taking account of structural deformation, the theoretical values from the model derived in this paper considering the FSI effect are closer to the experimental values. Finally, by using the orthogonal design method, FSI simulation was carried out to analyze how the key dimension factors influence the structural stiffness of the spindle, and it is concluded that the thrust bearing’s stiffness is strongly influenced by the thickness of the thrust plate.

Key Technologies and Design Methods of Ultra-Precision Aerostatic Bearings

“…The more complex the aerostatic structure, the larger the deviation between the simplified analytical model and actual one. In contrast, the numerical [26,27] and CFD [28][29][30] methods have fewer calculations of assumptions and simplifications. In order to solve the problem of non-convergence in the finite volume numerical solution of the compound throttling global flow field, we propose an adaptive finite volume method (AFVM) to capture and subdivide the mesh near the wall [5,31].…”