Precision Design Of Throttle And Deformation Of Guide Plate For Oil Hydrostatic Guideway

The guideway is an important component of precision machine.The motion precision of the guideway will be directly engraved or enlarged to the ultra-precision machine,and the deformation of hydrostatic guideway is the main cause of motion error of the worktable.Therefore,it is necessary to study the deformation of guideway.As an indispensable throttling and regulating part of the constant pressure static pressure guideway,the machining error of the throttle will directly affect the static and dynamic characteristics of the static guideway.Therefore,it is necessary to study the accuracy of the throttle.In this paper,the influence of the size error,cylinder error,coaxial error and verticality error on the flow resistance of annular slot throttle is analyzed.It is found that the size error has the most significant effect on the flow resistance of the throttle,and the existence of shape and position error will reduce the flow resistance of the throttle,in which the verticality error has little effect on the flow resistance of the throttle,which is negligible.It is proposed to use needle gauge with high dimensional accuracy to replace annular slit throttle to complete throttle pressure regulation.A measuring device for flow resistance of annular slit throttle is set up,and the the flow resistance of the throttle is measured when the needle gauge is tilted and eccentric.The resistance value of needle gauge throttle in inclined state obeys normal distribution,which shows that needle gauge has good throttling stability.The comparison between ring slot throttle and needle gauge throttle proves that it is completely feasible to substitute needle gauge for throttle.The deformation model of hydrostatic guideway is established and simulated with ANSYS software.The deformation of guideway plate is analyzed when the table is in different position,the number of screws and the step distance of screw.The results show that the deformation of the guide plate decreases with the increase of the number of screws,and increases with the increase of the screw step distance.The deformation at the two ends of the compression plate is larger than that at the middle position.The equal step screw arrangement is divided into three types:triangle,rectangle and parallelogram.It is found that the deformation of the pressing plate is the smallest in the triangular arrangement mode,and the change in the parallelogram arrangement mode is the smallest.The shape is the largest.Finally,the hydraulic guideway test-bed is set up,and the theoretical analysis results are verified by experiments.