Dynamic Analysis And Reliability Design Of The Shell Of Shearer Rocker Arm

As an important part of the mining process,the stability of the rocker arm drive system of shearer directly determines the working efficiency.The safety and stability of the rocker arm shell is the basic guarantee for the normal operation of the drive system.Therefore,the dynamic analysis and reliability design of rocker shell are very important.In this paper,the MG300/700-WD shearer rocker drive system is taken as the research object,and the dynamic analysis,fatigue analysis and reliability design of the rocker arm shell are carried out.The main research contents are as follows:(1)Based on the principle of substructure method,ANSYS is used to extract the shell parameters.Considering the factors of shaft,gear,bearing,planetary gear mechanism and shell,the finite element dynamic model of gear transmission system with coupling shell is established by lumped mass method.Based on the theory of coal breaking,the force of a single pick is calculated,and then the force of a single pick is randomized based on Rayleigh distribution,and then the random load spectrum of the drum is obtained when the rocker arm works.The dynamic response of gear transmission system is solved by Newmark-beta method,and the correctness of the model is verified by comparing with the experimental data.(2)The natural frequencies of the rocker arm drive system before and after the coupling shell are analyzed,and the modal analysis of the shell is carried out to illustrate the influence of the coupling shell on the natural frequencies of the gear drive system.Based on the results of dynamic analysis,the force acting on the shell of rocker arm system is analyzed,and then the transient dynamic analysis of the shell is carried out.Fitting the SN curve of the shell,using nCode to analyze the fatigue life of the shell based on the transient dynamic results and SN curve.(3)Taking the parameters that may affect the fatigue life of the shell as random variables,using BP neural network fitting function the functional relationship between the fatigue life of the shell and the random parameters.The reliability model of rocker arm shell fatigue life is established,and the reliability and reliability sensitivity of shell fatigue life are solved by quadratic fourth moment method.Identify vulnerable sites.In this paper,the dynamic model of the rocker gear transmission system of the coupled housing is established and its correctness is verified.The transient dynamics analysis of the rocker arm shell shows that the maximum stress of the shell is less than the allowable stress during the working;the fatigue life analysis is carried out to determine the easy-to-failure part at the chamfer of the lower joint,on the basic of the shell Anti-fatigue reliability and reliability sensitivity analysis were performed.