直驱转台双静压导轨油膜刚度与承载力研究

Study Between Oil Film Stiffness and Bearing Capacity of Double Hydrostatic Guideway on the Direct Drive Turntable

静压导轨是现代重型精密机床的关键部件,其油腔油膜刚度大小直接影响着直驱转台的刚度和固有频率,进而直接影响到工件的表面质量与加工精度,因此对于油膜刚度的分析有着重要的意义。针对静压导轨的工作原理进行了阐述,建立了静压导轨油腔模型,在此基础上对铣车复合加工中心在车、铣工况下的油膜刚度进行了计算,并且以MATLAB为工具得到了切削轴向分力和工件重量对油膜刚度、厚度的影响曲线。研究表明,随着轴向力和工件重量变大,油膜刚度近似线性增大,油膜厚度非线性减小,减小速度原来越慢。

Hydrostatic guideway is the key components of the modem heavy precision machine tool,whose oil film stiffness directly affects the size of direct drive turntable stiffness and natural frequency and affects the surface quality and the machining accuracy of the workpieces.Therefore,it is important to analyze the oil film stiffness.It described the working principle of hydrostatic guideway,established oil chamber model of the hydrostatic guideway and then calculated the film stiffness of mill-turning center on the conditions of milling and turning.At last,the film stiffness and thickness curve about cutting axial force and the workpiece weight were attained in the tool of MATLAB.The curves show that,with the larger axial force and the workpiece weight,the film stiffness approximately linearly increases and film thickness nonlinearly decreases,whose speed is lower and lower.