| The crawler travelling gear supports the whole weight and the working load of hydraulic excavators in the working process, thus its reliability dramatically influences the efficiency and safety of the excavator. The fault mechanism of the crawler travelling gear of the WY16 hydraulic excavator has been thoroughly studied in this paper, such as the fracture of connecting bolts, the seal failure and the wear failure of track wheels, etc. The reasons of connecting bolts fracture were analyzed through analytical calculation and numerical simulation, based on which, the improvement scheme was provided. In addition, the failure location and mechanism of seal on track wheels were analyzed deeply, and the pressure on the floating seal ring was simulated by the finite element method software ABAQUS and the fluid simulation software FLUENT. Furthermore, the effect of track wheel speed on its sealing performance was studied, and the main factors affecting track wheel floating sealing performance were determined. Moreover, the measures to improve the sealing performance of floating seal assembly were discussed broadly. Finally, the wear failure of track wheel was analyzed, the relationship between wear of track wheel and surface yield strength was studiedBased on domestic and foreign literatures, the composition and working principles of the crawler travelling gear of hydraulic excavator were described comprehensively. Furthermore, the research results of the failures of crawler traveling gear were also expounded. The common failures of crawler travelling gear on WY16 hydraulic excavator were explained.The problems that the connecting bolts of the sprocket failed in the working process were studied thoroughly. In addition, the connecting bolts were analyzed and calculated deeply by using the finite element analysis software ANSYS, and drew the conclusion that the decisive reason for the bolting failure was that the pre-tightening force was too small and the loosenessproof for bolts was not considered.The sealing structures and principles of track wheels were introduced. In addition, the sealing failure of floating seal ring was studied deeply. The whole finite element model of the track wheel was established in the finite element software ABAQUS, based on which, the force of rubber on the floating seal ring was obtained conveniently. The fluid calculation model of the lubricating oil in floating seal ring clearance was established by using the fluid simulation software FLUENT. Moreover, the pressure of lubricating oil on floating sealing ring at different rotation speed was studied and the relationship between rotational speed and sealing performance was analyzed. Finally, the main reasons for the failure of the track wheel were determined preliminary and the solutions of improving the sealing performance of track wheel were discussed.The wear between outer edge of track wheel and track link was serious during turning. The dynamic model of hydraulic excavator was established in RecurDyn. The maximum lateral force was determined Furthermore, the calculating method for wear of track wheel was discussed. Finally the measures to decrease the wear of track wheel were proposed.Based on numerical simulation technology, the fault mechanism of the crawler travelling gear of the hydraulic excavator was analyzed, and the improvement schemes were provided. Moreover, the results were obtained in this study to shed light on the design of crawler travelling gear of excavator. |
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