摘要
为提高气浮转台的承载力和刚度,以气浮转台的止推轴承为研究对象,采用有限差分法对可压缩的雷诺方程进行离散和求解,探究气浮止推轴承节流孔排数、孔数、分布方式对轴承承载力和刚度的影响。结果表明:随着节流孔排数逐渐增加,排数对气浮止推轴承承载性能的影响逐渐减小;相邻排的节流孔排布方式对气浮止推轴承的刚度有一定影响;当节流孔总数确定、轴承每排孔数相等时,承载性能最优;适当将两侧节流孔靠近出气口,可以在较小气膜间隙下获得较大刚度。研究工作为高刚度气浮转台的设计提供了一定理论依据。
As a core component of precision machining equipment,the aerostatic rotary table plays a pivotal role in high-precision manufacturing and ultra-precision measurement applications.Among its performance indicators,stiffness serves as a critical parameter,as even slight improvements in rotary table stiffness may markedly enhance positioning accuracy and dynamic response during the machining process.The axial stiffness of an aerostatic rotary table is primarily provided by the thrust bearing,which is key in maintaining rotor stability,resisting external disturbances,and ensuring the sustained reliable operation of the system.Therefore,an in-depth investigation into the relationship between the structural parameters of the thrust bearing and its performance is a vital step toward improving the overall performance of aerostatic rotary tables.In recent years,extensive research has been conducted on the load-carrying characteristics and performance optimization of aerostatic thrust bearings.These studies have,to some extent,revealed the mechanisms underlying performance variations.However,in practical engineering design,the performance of thrust bearings is normally affected by the coupled effects of multiple structural factors.In particular,parameters such as the number of restrictor rows,the number of orifices per row,and the spatial distribution of orifices jointly determine the pressure distribution within the gas film and the overall stiffness of the bearing.Currently,research still needs to fully consider the interactions of multiple factors.Systematic summaries and theoretical guidance are still unavailable.This somehow prevents the optimization design and broader application of high-stiffness aerostatic rotary tables and exposes the inherent constraints of existing design methodologies.To further improve the load capacity and stiffness of aerostatic rotary tables,this paper takes a thrust bearing as the primary research object.The Reynolds equation for compressible fluid lubrication is discretized and solved employing the finite difference method,combined with numerical simulation techniques,to systematically investigate the effects of restrictor row number,orifice number,and distribution pattern on the bearing’s load capacity and stiffness.Results demonstrate as the number of restrictor rows rises,both load capacity and stiffness are improved,but the marginal improvement gradually diminishes.Once the row number exceeds a certain threshold,additional rows do not contribute much to enhancing performance.Furthermore,the arrangement of orifices between adjacent rows has a pronounced impact on stiffness,as different distribution patterns alter the uniformity of the pressure field within the gas film,thereby affecting axial stiffness.When the total number of orifices is fixed and the number of orifices per row is equal,the bearing reaches optimal load capacity,indicating that symmetry and balanced allocation of orifices are crucial factors in improving performance.Moreover,positioning the outermost orifices closer to the gas outlet helps achieve higher stiffness under smaller film clearances,providing insights into high-precision applications.Overall,this paper reveals the rational selection of the number,distribution,and arrangement of restrictor orifices is key to achieving an optimized balance between load capacity and stiffness in aerostatic thrust bearings.
作者
张国庆
郭羽
于贺春
王文博
李优华
黄亚甫
寇新俊
ZHANG Guoqing;GUO Yu;YU Hechun;WANG Wenbo;LI Youhua;HUANG Yafu;KOU Xinjun(School of Mechatronics Engineering,Zhongyuan University of Technology,Zhengzhou 451191,China)
出处
《重庆理工大学学报(自然科学)》
北大核心
2025年第9期85-92,共8页
Journal of Chongqing University of Technology:Natural Science
基金
国家自然科学基金面上项目(51875586)。
关键词
气浮止推轴承
刚度
数值计算
优化设计
air floating thrust bearing
stiffness
numerical calculation
optimized design
