Contact Stiffness Analysis Of Joint Surface For NC Machine Tools Considering Guide Rail

With the rapid development of science and technology, CNC Machine graduallyto more high-speed、more high-precision and more high-reliability direction. In themechanism side, the global stiffness of machine tool is determined by different basicstructure‘s stiffness and different combine surface’s stiffness, among of variouscomponent connect with each other to form all types of joint surface, but constitutejoint surface between two component has reciprocal motion, joint surface‘s stiffnesscompare with two components‘s stiffness is general lower. Machining precision andworking life depend largely the quality of guide rails, therefore, this paper is aimed atcontact stiffness of joint surface considering rolling guideways for studing andanalyzing, that have implication for improve whole rigidity of NC machine tool.This article bases on the research for Hertz contact theory in contact mechanical,establishing formula to solve the contact stiffness for joint surface, theoretical modelof contact stiffness is got.It studies contact theory and its application in finite element analysis, geometricmodel and finite element model are established for analysis object, and do somesimulation anslysis on it. solve corresponding variation law of contact elasticdeformation under different load, the deformation drawing of joint surface are got,show us change situation of different result under different loads in the whole model,the relative curve between load and deformation is fitted, the change rule is obtainedabout contact stiffness of joint surface. According to text principle with rollingguideways of specific condition for static stiffness test of joint surface, usingexperiment data for calculating to get contact stiffness for joint surface value. The testresult is compared with FEA result and theoretical computation result to validate finiteelement model and theoretical model is feasible. Summarized the effects law ofdifferent factors on static stiffness, it build a good foundation for further research oncontact stiffness relate to different type of rolling surface. The factors affecting dynamic features are concluded, based on spring-damperelements, dynamic theoretical model and finite element model(FEM) of RG joint areestablished, by means of the methods that combine calculation of theoretical modeland modal analysis of FEM for dynamic features study.By analyzing and researching for static and dynamic characteristic of NCMachine Tools considering Guide Rail, to facilitate optimization on structuralproperties of the entire machine.