| With developing of national economy, excavator as one of the most important mining equipments, it plays a more and more prominent effect and role. For the large mining excavator, either rotating mechanism, pushing press mechanism, lifting mechanism or traveling mechanism utilize gear transmission unit to transmit, gear transmission is widely used in machinery equipment, its failure and damage often cause trouble of transmission system even the whole equipmentits. Therefore, researching the movement of gear transmission can avoid trouble of transmission system or the whole equipmentit and improving performance of mechanical transmission.Crawler mechanism is an important part of the excavator, my paper uses crawler mechanism, it endures variety of dynamical loads when the excavator is working. The travel reduction gearbox is one of the major component parts, and it is the core of power transmission. As the large and overloading mining excavator, the transmission structure of travel reduction gearbox should be have efficient and reliable, Which can reduce unnecessary economic losses, and therefore create greater economic and social benefit.Based on reading plenty of reference and deeply theory, the mainly task of my paper is as follows:(1)Described the present development and trend in crawler excavator, at home and abroad, and compare the domestic technology with abroad. As the competition is increasing in the global machinery industry, although the domestic excavator still has a wide gap with advanced technology in design and development, the nap is narrowing, and it has already formed dependent brand which has international competition in some extent. And describe the core of traveling parts on excavator-the advanced design level of the travel reduction gearbox in system.(2)Perform analysis of the structure of the traveling reduction gearbox on crawler excavators, and obtaine the force characteristics of the fixed axis gear and planetary gear when they mesh with other gears, calculate the gear tooth force of the active gear and driven gear in fixed axis gear and the solar wheel and planetary gear. Through calculating the coincidence degree of the fixed axis gear and the planetary gear, the tooth number of meshing gears can obtain. And using the ishikawa formula to calculate meshing stiffness which is in the active gear and driven gear in fixed axis gear and the solar wheel and planetary gear, the comprehensive time-varying meshing stiffness of the active gear and driven gear and the solar wheel and planetary gear can obtain.(3)Base on 3d design software UG to build modeling for the travel reduction gearbox of crawler excavators, then through the interface file into the engineering application software ADAMS. Simplify the established modeling base on it ensures that the simulation in ADAMS could carry out in the smooth and efficient. Apply constraint and contact for the travel reduction gearbox of crawler excavators, so the rigid body dynamic simulation model is builded, through calculation the speed and load torque in the input and output drivers can obtain. After the dynamic simulation, I can analyze the meshing force of the active gear and driven gear in fixed axis gear and the solar wheel and planetary gear in time domain and frequency domain, and output speed. Through compare the calculated meshing force with the simulation results, which are in fixed axis gear and the solar wheel and planetary gear, I obtain that the meshing force of the second sun gear and planetary are the largest and significant vibration.(4)Consequently, introducing the rigid-flexible coupling theory, as the meshing force of the sun gear in the second row is more larger, therefore the sun gear was transformed to flexible body in ANSYS software, then introduce the flexible body into ADAMS analysis software to perform dynamic analysis of the rigid-flexible coupling, check its strength and analyze the meshing force and the speed of the second sun gear and planetary in time domain and frequency domain. |
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