| Coal industry is an important basic industry in China,coal mining machine in the coal mining mechanization occupies a pivotal position,improve the performance of coal mining machine is the coal industry to improve production efficiency,increase production,to ensure safe production of an important part.The cutting section of the coal mining machine is the core component of the coal mining machine,and the transmission parts in the gear transmission system are prone to fatigue damage which leads to coal mining machine failure.This paper takes the MG500/1130-WD coal miner as the research object,through the combination of theoretical analysis,simulation and experimental methods,the kinetic characteristics of the gear mesh transmission under different working conditions are studied,the force prediction of the transmission parts is carried out based on the experimental data of the coal miner to build a network,and the fatigue damage of the gear transmission with errors is analysed.It has a certain reference role for the study of the mechanical characteristics of gear transmission system and transmission parts.The specific work is as follows:(1)Analysis of the structure and working principle of the drive system of the cutter section of the coal mining machine,modelling and overall assembly of the cutter section components using Solid Works,and interference checking of the assembly to avoid subsequent simulation failure.The mechanical characteristics of the key transmission components are analysed,including the static and dynamic analysis of the idler pulley set,and the dynamic equations of the straight gear transmission are established.Operating parameters such as drum load and gear meshing frequency are calculated to provide theoretical support and data for subsequent work.(2)The idler shaft load test system was constructed by modifying the idler shaft,and the experimental test of the whole coal mining machine was carried out to obtain the micro-strain signals from the idler shaft sensors in the experimental test,and to analyse the forces on the idler and idler shaft.A rigid model of the cut-off section of the coal miner was established,and a flexible body of the rocker arm was generated using Hyper Mesh to replace the rigid body,and rigid-flexible coupling simulations were carried out in ADAMS to verify the accuracy of the model.The dynamic characteristics of gear meshing are investigated,and the fluctuation law of gear meshing force is investigated by analysing the dynamic characteristics of gear transmission under steady state and sudden change working conditions.By analysing the dynamic characteristics of gear meshing at different traction speeds,the effect of load torque on gear meshing force is analysed,the relationship between gear meshing force and traction speed is summarised,and the change in mechanical characteristics of the idler shaft during the experimental test is analysed.(3)Based on the experimental data,the mechanical characteristics of the transmission part idler shaft are analyzed,the idler shaft is parameterized,and the multi-input parameter test design is constructed using the Six Sigma module.The parameters that have the greatest impact on the local stress of the idler shaft are obtained through local sensitivity and response surface optimization.Divide the array of experimental design for machine learning,verify the importance of parameters through the forest algorithm RF model,compare with the prediction models of support vector regression SVR and BP neural network,select the BP neural network with better prediction performance as the learning model,optimize the initial weight and threshold of BP neural network through multiple algorithms,and GA-BP network effectively improves the accuracy of the stress prediction of the idler shaft,Provide reference for the size design and mechanical characteristics analysis of the idler shaft.(4)The definition of parallelism error and the mathematical model of the gear with the error are developed.The influence of parallelism error on the gear transmission is investigated through theoretical calculations.A three-dimensional model of gear meshing is established,and finite element analysis is carried out on normal gears and gears with parallelism errors.The effect of parallelism errors on gears in the vertical plane and axial plane is investigated,and the variation of stresses in gears with error values is obtained.Based on the finite element simulation results,fatigue life analysis was carried out using n Code to investigate the effect of parallelism errors on the life of a normal gear drive and the hazards of different in-plane errors on gear contact drives.There are 74 diagrams,14 tables and 74 references. |
