Dynamics Research On Working Attachments Of Mechanical Excavator

The large mine mechanical excavator is one of the important equipment for domestic and international mining. Whether the working performances of the attachments are well is directly related to the properties of the machines. The practice shows that it shall start from the study on dynamics of working attachments, if improve the machine performance.From the excavator’s theoretical dynamic characteristic curve, on the basis of extreme working conditions, with the natural system of working attachments as the computation model, and the handle and boom as elastomers, nine-degree of freedom dynamic model of the working attachment is established by using multi-body dynamics theory, and the maximum dynamic load and dynamic load coefficient of the components are solved by using lagrange’s equation. Based on the work that we have done, establish elastic mechanics model of two-degree of freedom by ignoring the freedom that make weaker influence on whole structure dynamic. And compare it with the model of multiple degree of freedom dynamic.Make an analysis on the various factors that affect the system dynamic load, and identify possible ways to reduce the dynamic load.Moreover, make study on the kinematics of excavator with the move-point method. Unlike fixed-point method to make the pushing shaft center as the reference point, move-point method makes the meshing point of pushing gear as the reference point. And get the mining track based on the crowd arm and hoist rope speeds. In order to meet the coefficient of full conditions, make an analysis on the crowd arm and hoist rope speeds. The objective of this work is to find the optimal crowd arm and hoist rope speeds.To sum up the work above, it enrich the excavator design theory. At the same time, the methods of modeling and analysis have big significances to other types of mechanical system.