Analysis And Simulation Of Static And Dynamic Characteristics Of Liquid Cylindrical Hydrostatic Guideway

With advantages of low attrition, high load capacity, high stiffness, smoothmovement under low speed and long life, hydrostatic Slide has been widely used in largemachine tools, heavy machine tools, CNC machine tools and precision machine tools. Ithas become a leading means for modern machine tool bearings. This study is about theanalysis and simulation of the static and dynamic characteristics of the liquid cylindricalhydrostatic guideway, which use the technology of the static pressure. The guide spindle isstatic and the ram floats on the spindle under the action of the oil film pressure, movingalong the cylindrical guide shaft. Liquid cylindrical hydrostatic guideway is similar withhydrostatic bearing in structure, but the ram just moves along the shaft without high speedrotary motion. The guideway is in the form of internal feedback throttle which is adoptedby the hydrostatic bearing. In this way, the throttling device can be directly made on theram. The structure is simple with eliminating the separate choke and the oil film stiffnessis strong. There is little literature researching on liquid cylindrical hydrostatic guideway.In order to provide theoretical basis for the optimization design of the CNC machine toolguideway, we did research on the theoretical analysis and numerical simulation about thestatic and dynamic characteristics of the liquid cylindrical hydrostatic guideway anddiscussed its influencing factors.The main research content of this paper are as follows:(1)Deduce the expression of static characteristics of the liquid cylindrical hydrostaticguideway. Draw the curves of the static characteristic with Matlab software. The curvesshow the ralationship between bearing capacity, stiffness, flowrate with guide raileccentricity and load.(2)Deduce the force balance equation and the flow continuity equations of the slide.The linear differential equations of the cylinder hydrostatic slide were obtained afterlinearization. Then get the transfer function by using Laplace transform and deduce themathematical model of the cylindrical hydrostatic guideway. Then the influence of theinitial oil film thickness and oil viscosity, oil supply pressure on the performance of the slide were analyzed in time domain and frequency domain by Matlab.(3)In order to verifies the correctness of characteristic analysis further and providepowerful basis for the selection of above parameters, numerical simulation was put on theliquid cylinder hydrostatic guideway by using Fluent.