Study Dynamics And Reliability On Transmission System Of Hoist Machinery Of Electric Mining Shovel

Electric mining shovel hoist machinery as one of the main machinery in the excavation process,the work performance and the reliability of mechanism directly affect the overall performance of the excavator.In the harsh mining environment,the hoist machinery not only bear the huge load effect,but because of the uncertainty of environment and the operator's uncertainty,making each excavation process has a large random load.Therefore,it is great significance to study the dynamic reliability of transmission system of hoist machinery under the random conditions.Based on the analysis of the main failure modes of the transmission system of the hoist machinery,and considering the multi-action effect of load and the degradation of structural strength,this thesis takes the WK-55 electric mining shovel of Taiyuan Heavy Machinery Group as the research object.The dynamic reliability model of key components of transmission system is established.The main contents of this thesis are as follows:(1)According to the data provided by Taiyuan Heavy Machinery Group,this thesis uses UG 3-D modeling software to construct the 3-D solid model of hoist machinery transmission system.Through x_t format file the 3-D model data of the transmission system can be accurately converted into ADAMS dynamics software,and the constraints are added to establish the dynamic model of the transmission system.Using the ANSYS software,the secondary gear shaft is flexible to generate MNF format file.Through the “Rigid to Flex” command in the ADAMS software,replace the original rigid secondary gear shaft,and the rigid-flexible coupling dynamics model of the hoist machinery transmission system is established.(2)According to the dynamic simulation data,the dynamic load-time course of the parts in the transmission system is obtained.According to Hertz contact theory and bending and torsional strength synthesis theory,the stress-time course of parts is obtained.The stress distribution of the parts is analyzed statistically by using the rain flow cycle counting method,and the probability distribution and the distribution parameters of the parts stress are obtained.(3)According to the characteristics of electric mining shovel,the working condition of each excavation “excavation-rotary unloading-unloading-rotate to work plane” is taken as the load once.According to the dynamic reliability model,relationship between the reliability and the time of the transmission system is calculated.In this thesis,the Gamma function is used to describe the structural strength degradation process,and the Gamma function shape parameter and scale parameter are estimated by combining the P-S-N curve of the material.(4)Using Kriging surrogate model technology,the gear structural performance function proxy model is established,and the error of agent model is analyzed.Compared with the traditional method that using FEM program many times,the proxy model can improve the efficiency.According to the function of structural performance,using the Monte Carlo random sampling method and the Kriging surrogate model technique to obtain the reliability of all gears in transmission system.