Design And Precision Analysis On High-stiffness Linear Rolling Guide

Modern manufacturing industry has put forward higher requirements for machinetools to have several excellent properties, such as high precision, high speed and highstiffness. Machine tools have long been one of the measures of a country’s developmentlevel of science and technology and modernization. Ultra-precision machine tool mainlyconsists of spindle system and the guide rail system, and the guide plays an importantrole in a machine tool. Linear rolling guide has a compact structure, rapid responsivespeed, good bearing performances, easy installation, etc. It has been widely used inmachining centers, CNC machine tools and other industries.The tool uses a T-shape layout overall. On the basis of making clear the machinetool’s requirements to the guide, this paper first completes the connection design of theguide in spindle system, the guide and the slide design, the rolls design, the "motor+ball screw" drive system design and other ancillary components design of the guidesystem one by one, according to a guidance of the design process. Then the papercompletes the design of tool slide rail using the same method, eventually completing theoverall design of the machine tool’s guide systems.The accuracy of guide precision and it’s influencing factors are analyzed toimprove the precision of the guide by appropriate methods. The stiffness of transmissionsystem in the spindle has been calculated, which is used to determine the axial stiffnessbetween the rail and the slide.Based on the Hertz contact theory, the contact area’s conditions (mainly refers tothe maximum deformation and the maximum stress) of the ball and roller have beenstudied comparatively. Results show that the roller has a higher rigidity and a betterstress distribution than the ball, and the roller’s radial stiffness has been calculated.Preload on the rails were also studied. Static simulation of the rail system has beenprogressed to get it’s stiffness, which has verified the high stiffness of the guide.Components needed to be optimized in the design progress. First, the nut board’sresponse surface has been optimized using the finite element software ANSYS.Secondly, taking the slide as the example, the paper has completed the topologyoptimization of the parts to get a reasonable material layout under the condition ofmeeting the stiffness. Finally, as the rolling guide has a poor ability of resisting the earthquakes, modal analysis of the spindle rail has been done to obtain the rail’s naturalfrequencies and mode shapes.