| The automotive hub bearing is an important part of the automotive load-bearing and providing an accurate guide for the automobile.Its quality and performance play a vital role in the driving experience and driving safety of the automobile.Overseas rotary forging technology has matured,and the key manufacturing technology of riveted automotive hub bearing has been grasped.The riveting and assembly process of the hub bearing has a great influence on the bearing life.Because of the lack of the basic research in China,there is a big gap between the reliable service life of the automotive hub bearing and the long life and high reliability target of 250 thousand kilometers.This thesis,taking the bearing life as the optimization goal,carries out the theoretical analysis and finite element simulation of riveting and assembly process of hub bearing.The effect of riveting and assembly process on the forming quality of the car hub bearing is studied in combination with the experimental results.Based on the study of riveting and assembly process with variable volume method,riveting assembly process analysis and optimization of the hub bearing unit with new structure are carried out.This thesis mainly focuses on the following aspects:(1)The theoretical analysis of riveting and assembly process of hub bearing is carried out,and the calculation and analysis model of riveting and assembly force is established.The main factors affecting the riveting and assembly process are analyzed,and the relevant technological parameters,such as the track of the rivet head,riveting angle,the feed per rotation and the final riveting time,are determined,providing the basis of theoretical analysis on riveting forming process.(2)The finite element simulation model of riveting and assemby of the hub bearing is established,and the influence of riveting movement track,riveting angle and finish time on the performance of hub bearing unit is simulated and studied.Considering the influence of shaft end riveting shape,shaft end bore diameter and clamping force,the optimum technological parameters of rivetin g and assembly of the hub bearing are determined.(3)The experiment of riveting and assembly process is carried out to analyze the quality of riveting forming of hub bearing,and the rationality of the theoretical model of riveting force of hub bearing and the finite element analysis model of riveting and process are verified.Combined with the experimental results,the riveting and assembly optimization process of the car hub bearing is established,and the prototype automotive hub bearing unit is manufactured,and the durability test is carried out.(4)A new hub bearing unit structure is proposed,and the finite element model of hub bearing riveting and assembly is established.The riveting force,clamping force,strain field and stress field in riveting and assembly are studied,and the riveting and process of the new hub bearing unit is studied,which demonstrated the improvement effect of the bearing structure.Finally,the deformation mechanism of the shaft end forming is revealed by metallographic analysis. |
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