| China Branch of the many rivers and lakes, vast sea, water, rivers, waterways and construction of large sea, grab dredger is an integral part of dredging machinery. Gear transmission is the most common type of slewing mechanism of the rotary crane, and also one of the most important and the most widely used mechanical transmission. Over the past, the research on the design of the main gear system is static, focusing on the aspects of strength check, and strive to meet the requirements of the strength of the gear so as not to the accidents of fracturing. With today's advances in science and technology, the direction of development of the gear system is moving to high-speed, heavy duty, high precision, and so on. The static designing can no longer meet the needs of demand. Dynamic design has become an inevitable trend in gear design. When dredging machine turning operations, size and direction of the gear by force is not static, time now for the gear strength check mainly static strength check of the way, taking into account the impact of the dynamic changes in the force, the main way to add dynamic factor considered, the result thus calculated is not accurate, nor the performance of stress during the rotary gear changes. In this paper, the installation of the rotary mechanism rotary gear backlash and gear drive function as a variable rotation mechanism study of dynamic contact force gear. The main contents are as follows:(1) According to the gear system dynamics, we set up a dynamic model of rotary gear pair, and get the mathematical model of gear dynamic meshing force was obtained, then analysis of meshing force motivating factors. With 18 m3 dredging machine as an example, the paper establish the gears mesh clearance nonlinear model, and, get the vibration of the gear mesh model under the gear side clearance incentives.(2) Analyse the 18 m3 dredger braking process of slewing mechanism motion of turning gear with three-dimensional modeling software SOLIDWORKS established under different backlash slewing gear assembly model, import the explicit dynamics software ANSYS/LS-DYNA, obtained the slewing gear pair in the process of braking dynamic tooth gear contact force and stress.(3) In this paper, three dimensional modeling software SOLIDWORKS 18 m3 dredger entity assembly model is established, the import into the dynamics software ADAMS established 18 m3 dredger multi-rigid-body virtual prototype model of slewing brake are analyzed under different backlash in the process of dynamic contact force. Using finite element software ANSYS to get the rotation of the pinion flexible body neutral files, import substitute rigid body in the coupled dynamics simulation in ADAMS, rotating pinion of the maximum contact stress are obtained.(4) Through the gear strength criterion, the use of ANSYS/ls-dyna software and the ADAMS software was carried out on the gear strength calculation, the result of the pinion and big gear ring of static strength and fatigue strength, and compares the two kinds of calculation result.Based on the grab dredger slewing mechanism of gear backlash as variables, the rotary gear dynamic force in the process of meshing parameters and stress change process, provide a basis for selecting reasonable future backlash, improve the installation accuracy, improve the service life and has practical application significance. |
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