Structural Strength Analysis Of Constant Velocity Joints For Car Drive-shaft By Finite Element Method

The modern economical car adopts the pattern of assigning of front-wheel drivemostly, and the constant velocity joint is one of the key components among them.At present,the constant velocity driving device which is composed of ball-cagetype constant velocity joint together with three pivot shaft type constant velocityjoint is used by automobile transmission system mostly. Because the structure ofconstant velocity joint is very complicated, the precision of making is high, anddifficulty of making is large. Our country introduces foreign special-purpose devicemainly at present, it is very expensive to make the investment. For this reason, ourcountry has regarded the constant velocity joint as one of the key part project tosupport especially.The ball-cage type and the three pivot shaft type constant velocity joints of theconstant velocity drive shaft on the F-F type car of a certain domestic factory wereregarded as research objects. The 3D models of the constant velocity joints werebuilt by using 3D re-created technology, then the finite element models of theconstant velocity joints were built by using ANSYS software, then the authorcarries out the study on the inner contact stress of the constant velocity joints bymeans of the connection of the finite element analysis, theoretic calculation and thetest.According to analysis, calculation and test, this thesis is made up of six chapters,and the research contents can include as follows:In chapter one, the structure and the excellence or disadvantage of variousuniversal joints were simply introduced, and according to the comparison, we canfind the excellence of the constant velocity joints. General situation of research anddevelopment was listed, the permitted limit stress of the constant velocity jointswas introduced. Finally, the main research contents and the meaning of this thesiswere put forward, and the author points out that the finite element analysis of theconstant velocity joints is one of the developing design directions, it has the widestfuture. In chapter two, the author introduced theoretic bases of the finite elementmethod. From the development of the finite element method to the sorts of thismethod, then from describing the contact problem to the finite element method ofcontact problem, and restriction arithmetic, the author introduced the theory of thefinite element. Then the author introduced various software of the finite elementanalysis simplify, and compared their excellence and disadvantage. Finally, theauthor introduced the function of ANSYS software using in this thesis in detail. In chapter three, the finite element models of constant velocity joints were built.Firstly, the measurements of the constant velocity joints parts were scanned tocomputer, according to the 3D re-created technology. Then, the models of theconstant velocity joints were re-created and simplified by using PRO/E software.Finally, the models were imported to ANSYS, then the element types were chose,the material attributes were defined, the finite element mesh was generated, thecontact parts were established, the constraint and boundary conditions were applied.This chapter made preparations for the next finite element analysis. In chapter four, the structural strength of the constant velocity drive-shaft wasanalyzed by using the finite element method. Firstly, the analytic finite elementmethod was chose, and the solution solver type and various parameters weredefined. Then, reading results from POST1 after solving the models by usingStructure U in ANSYS. For the ball-cage type constant velocity joint, its contactstress was analyzed, when it was in the ideal state and the actual state. The resultsindicate that the max contact stress occurs on the inner raceway in all states, andthe inner raceway is the weakest part in the ball-cage type constant velocity joint,its metal fatigue is the shortest, so the inner raceway should be paid more attentionin the optimum design. For the three pivot shafts type constant velocity joint, itscontact stress was analyzed, when it was in the ideal state and the actual state. Theresults indicate that the max contact stress occurs on the pivot shaft, and the pivotshaft is the weakest part in the three pivot shafts type constant velocity joint, its...