Research On Thermal Characteristics Of Rolling Linear Guides

The rolling linear guide is one of the key parts of the feed system of CNC machine tools.It is important to study the thermal characteristics and its influence rules of rolling linear guide rail to ameliorate the precision of the feed system of CNC machine tools and improve the performance of the machine tool.At present,the research on the thermal characteristics of rolling linear guide is mainly concerned with the influence of friction heat on the thermal characteristics of rolling linear guide,but does not consider the friction and friction heat of ball in and out reverser on the temperature of rolling linear guide.Therefore,it is necessary to conduct in-depth research on the thermal characteristics of rolling linear guide.HSR15A rolling linear guide is taken as the research target of this paper.The contact characteristic analysis model of rolling linear guide and the friction model of rolling linear guide considering the friction of ball in and out of reverser are established.The finite difference method is made use of establishing the transient thermal characteristic theoretical model of the guide rail section,and the thermal characteristic simulation analysis model of the rolling linear guide rail is established,and the temperature field and the law of temperature changing with time are obtained.The deformation of slider under vertical load and the effect of vertical load and operating speed on the temperature change of rolling linear guide are obtained by experiments.The main contents are as follows.(1)Referring to the correlative literatures on the thermal characteristics of the rolling linear guide at home and abroad,the research status and latest progress of the contact characteristics,friction characteristics and thermal characteristics of the rolling linear guide are summarized and analyzed,and the main research content and methods of this paper are determined.(2)The theoretical model of the contact characteristics of rolling linear guide is established,and the variation law of contact load and deformation of rolling linear guide under different loads is explored.The friction model of rolling linear guide is constructed,and the impact force of ball in and out of reverser is analyzed.The influence law of speed,ball radius and other parameters on the impact force of ball in and out of reverser is obtained,and the measures to reduce the impact force are put forward.(3)Based on the analysis of the heat transfer of the guide rail,the transient temperature distribution model of the rolling linear guide rail section is established by using the finite difference method.The thermal boundary conditions are determined and the heat conduction differential equation is solved.The temperature field of the guide rail section at different moments and the temperature distribution law when it reaches the steady state are obtained.(4)The static structure simulation analysis model of rolling linear guide is established,and the deformation and stress distribution.of rolling linear guide under vertical load are obtained;The simulation model of thermal characteristics of rolling linear guide was established,and the temperature distribution and the law of temperature changing with time in steady and transient state were obtained.Thermal structure coupling analysis is carried out to acquire the thermal deformation with temperature as load.(5)The rolling linear guide test platform is built and the rolling linear guide experiment is carried out.The influence of external load on the slider deformation and the influence of external load and operating speed on the rolling linear guide temperature are obtained.The experimental results are compared with the theoretical results and simulation results to verify the correctness of the theoretical model and simulation analysis.The paper studies the thermal characteristics of the rolling linear guide,analyzes the friction caused by the ball in and out reverser,and puts forward the measures to reduce the impact force of the ball in and out reverser,which provides a reference scheme for the optimization of the structure of the reverser;The thermal characteristics of rolling linear guide are studied,and the temperature field and temperature change law of rolling linear guide are obtained,which provides theoretical data for the thermal error modeling of CNC machine tools.