Research On Static And Dynamic Characteristics Of Dynamic And Static Gas Bearings Based On Bird Wing Profile Bionics

With the rapid development of modern industry and the increasing popularity of high-tech products,it has become an inevitable trend for the world’s manufacturing industry to develop to the field of ultra-precision and precision machining.Ultra-precision machining machine tool is the key means to realize ultra-precision machining.As the core component of the spindle of ultra-precision machining machine tool,the performance of the gas bearing directly affects the machining precision of ultra-precision parts.However,there are many problems such as low bearing capacity and poor rigidity of gas bearings.Therefore,aiming at the problem of how to improve the static and dynamic characteristics of the dynamic and static pressure gas bearing,this paper proposes a kind of bionic dynamic and static pressure gas bearing based on the bird wing profile.Through theoretical solution,simulation analysis and experimental verification,the static and dynamic characteristics of the bird wing profile imitating the dynamic static pressure gas bearing are studied.It provides the theoretical basis and design method for improving the bearing capacity and stiffness of the gas bearing.The flight mechanism of birds is studied,and the stress on the wings of birds is analyzed.At the same time,the aerodynamic force of birds is analyzed.Based on the mechanism that the streamlined outer profile of bird wings can reduce the air resistance during flight,the bionic structure of the streamlined outer profile of three kinds of bird wings was analyzed,and the characteristic parameters of the three kinds of bird wing profiles were extracted.Through curve fitting,the three-dimensional model of bird wing profiles was established.The flow field simulation analysis of the three-dimensional wing model is carried out.The basic equation of gas lubrication theory of dynamic and static gas bearings is modeled.The energy equation,momentum equation and turbulence model equation are introduced.The bird wing profile mimics the dynamic static pressure gas bearing structure design,including the design and simulation analysis of the small hole throttle and dynamic pressure groove,according to the simulation results to determine the structural parameters of the small hole throttle and dynamic pressure groove,the establishment of the bird wing profile bionic dynamic pressure gas bearing three-dimensional structure model.The static and dynamic characteristics of bird wing profile are analyzed,and the flow coefficient equation is introduced.Based on Solidworks,the three-dimensional model of bird wing contour imitating the dynamic hydrostatic gas bearing film was established,and the static and dynamic characteristics were simulated by Fluent software.Through the comparative analysis of the bearing capacity and stiffness of the small-orifice throttling and the miter groove,the increasing effect of the bearing capacity and stiffness of the bird-wing profile imitating the dynamic hydrostatic gas bearing under different air supply pressure,eccentricity and spindle speed was studied.Based on the dynamic grid technique,the effects of perturbation frequency,film thickness and rotational speed on dynamic stiffness coefficient of aerostatic bearing modeled by bird wing profile were simulated and analyzed.The bearing capacity of dynamic hydrostatic gas bearing modeled by bird wing profile was tested,the correctness of theoretical model and simulation results were verified,and the reference was provided for the subsequent bionic technology research of dynamic and hydrostatic gas bearing.