| With the development of automobile industry, the automobile industry has madeconsiderable progress. No matter it is shape or the key components of the automobile haveshown great improvement. On one hand people enjoy the convenience brought by technologyprogress, on the other hand people demand more and more safety on the driving. Hub bearingunit as one of the key parts of automobile, plays an important role in bearing and transmission.In recent years, automakers and suppliers have higher requirements in its life and safety. Inorder to meet all the requests, the hub bearing unit has been constantly upgrading, it isdeveloping toward integration，lightweight，installation ease.Compared to the current two generation hub bearing unit, the widely used third generationhub bearing unit in addition to have very different in structure, another significant identity is thesuccessful development of the minus clearance. The reasonable clearance can increase theservice life of the hub bearing unit, increase the hub bearing units stiffness, and improve drivingsafety. But the detection of hub bearing unit minus clearance technique, relatively speaking notvery perfect, operation is complicated, efficiency is low. The following work has been done tosolve the detection of hub bearing unit negative clearance.Using the Hertz contact theory to derive the formula of axial rigidity of hub bearing unit,and getting the relationship between hub bearing unit Axial load and axial stiffness, becauseof the deterministic relationship between the stiffness and frequency, we can indirectlyobtained the relationship between vibration frequency of hub bearing unit and axial load. Byanalyzing stress and deformation of the hub bearing unit, completed the derivation of theformula that can compute hub bearing unit negative clearance and got the relationship betweenthe hub bearing unit axial load and its negative clearance. Confirm that hub bearing unit has adetermined relationship the minus clearance and it is vibration performance, lay the theoreticalfoundation of simulation and experiment in this paper according to the established relationship.By analyzing the hub bearing unit, four effect factors of the vibration are determined, andestablishing the rigid-flexible coupling model of hub bearing unit. Doing the modal analysis ofthe rigid-flexible coupling model of hub bearing unit by dynamics software ADAMS, using orthogonal test method, determined the influence degree of the four factors that affect the testindex, did the simulation and analysis in view of the effect of hub bearing unit negativeclearance on the resonance frequency, got the relation curves between negative clearance andresonance frequency.Complete the vibration experiment of the hub bearing unit, by doing the vibration test ofhub bearing unit which have different negative clearance, and analyzing the frequency signal,get resonance frequency of the hub bearing unit, establish the relationship curve between thehub bearing unit negative clearance and resonance frequency, and compared with thesimulation results, verify the rationality and correctness of the simulation analysis.Summarize the detection method of hub bearing unit negative clearance according to thehub bearing unit simulation analysis and results of the resonance test. In view of currentsituation the factory faced that need to detect the negative clearance for various models andlarge quantities, raise the thought of parametric modeling and design the device of theresonance frequency detection. |
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