Research On Thermal Expansion Of Mechanical Parts

With the improvement of measurement accuracy and mechanical accuracy,the accuracy of modern precision engineering has entered the micro nano Era.The influence of thermal deformation on mechanical precision has not been ignored,therefore,the research on the mechanism of thermal deformation,the reduction of thermal error and the compensation technology have been paid more and more attention by scholars in the field of industry.It is of great significance to study the influence factors of the thermal expansion law of metal on the thermal deformation mechanism of mechanical equipment,whether it is on the basis of theoretical research,or to improve the practical application of technology has a profound reference value.This article is supported by two National Natural Science Foundation Project: ?Mechanical Complexity Body Thermal Robustness Fundamental Research(No.51175142)and ?Coupled Modeling And Influence Research In Functional Surface Structure And Performance(No.51490660/51490661)?,made the mechanical parts in the most basic and common parts of the Round bar,hollow,shaft as research subjects,research its thermal deformation of accurate simulation deeply.Content of this paper includes:Selected different metal materials of different shapes of rods as the test object,observe the axial thermal expansion law,to analysis of the factors affecting the thermal expansion coefficient.Based on the existing standards,the test of the thermal expansion coefficient of the material is made of a certain size bar,using the thermal expansion test device to measure the thermal expansion data.However,the factors that influence the thermal expansion coefficient of the parts have not been considered.Therefore,we select a variety of shape parameters of the test pieces,analyzed the effect of shape on the thermal expansion coefficient through experiments.The influence of temperature field on thermal expansion coefficient of metal parts is also discussed.It provides a reference for the further study of thermal deformation theory.Based on our existing research results and experience,the regularity of the radial thermal expansion with the size of the body was studied on the Shafts and holes commonly used in Engineering.We designed a special fixture.The fixture can meet measurement for different size parts,significantly reduced the design time due to the different size parts requirement,improve the efficiency of the experiment.Thirdly,putting forward the mechanical shaft hole functional size theory,based on the optimal thermal fit theory and mechanical thermal robust structure design.Solve the problem that equipment size change under conditions due to thermal expansion and the actual size of assembly deviates from the design dimension,Realization of equipment performance guarantee,is an extension of the existing structural design theory.