Research On Monitoring And Diagnosis Method Of Chain Drive System For Heavy Scraper Conveyor

The chain drive system has the advantages of long transportation distance,large transportation volume,high strength and continuous transportation,which plays a major role in traction and load bearing during mining transportation for the scraper conveyor.As the "artery" of mine production,scraper conveyors are constantly developing towards heavy-duty,intelligent and high-reliability.The chain drive system is a key part of scraper conveyor,and its working state directly determines whether the scraper conveyor can operate safely and reliably,which is of great significance to the safe production of coal mines.As a typical continuous closed transmission system,the failure of key components of the chain drive system is the main factor that causes the failure of the scraper conveyor.Considering the difficulty of post-maintenance for the heavy-duty scraper conveyor,it is necessary to conduct real-time status monitoring and fault diagnosis of the chain drive system,so as to develop reasonable maintenance strategies to ensure the safe and reliable operation of the chain drive system.Supported by the National Natural Science Foundation of China “Basic Research on Intelligent Driving System of Heavy-duty Scraper Conveyor”(No.U1510205)and the Science and Technology Program of Jiangsu Province “Key Technology of Intelligent and Heavy-duty Scraper Conveyor with High Reliability”(No.BY2015023-08),this dissertation has carried out research on the monitoring and diagnosis methods of the chain drive system for the heavy-duty scraper conveyor.This work is carried out based on multi-body dynamics,state observer,signal processing,fault diagnosis and other related theories and methods.The purpose of the corresponding research is to master the dynamic characteristics of the double-chain drive system,and study the monitoring method of the chain drive system based on tension analysis and the fault diagnosis method of the chain drive system based on vibration analysis of the middle groove,so as to provide the necessary theoretical support and technical solutions for ensuring the safe operation of heavy-duty scraper conveyors.The main contents include:(1)Based on the introduction of the basic structure and the working principle of the scraper conveyor,this dissertation analyzes the meshing transmission mechanism as well as the kinematics and dynamics of the chain drive system.The experimental platform is constructed to carry out field experiments under different working conditions.The experimental data are obtained to provide the necessary basis for verification of the research content involved in this dissertation.(2)Firstly,the study on dynamic characteristics of the chain drive system is carried out.Parametric modeling of the chain drive system is achieved by setting geometric parameter relationships and building model skeletons;Considering the structural complexity of the chain drive system and the difficulty in the study of its dynamic characteristics,a virtual prototype model of the chain drive system with double-chain traction is established,which comprehensively considers the complex interaction among the components.Based on the theory of multi-body dynamics and contact collision,the dynamic simulation analysis of the chain drive system is carried out,where the dynamic characteristics of the chain drive system under different working conditions are studied.(3)Secondly,the study on tension distributed monitoring of the chain drive system based on the state observer is carried out.The incidence relations between the running states and the dynamic characteristics of the chain drive system are analyzed,and a discrete mathematical model of the chain drive system is established based on the finite element method;The state space model is constructed according to the dynamic equation of the chain drive system,and the research on the construction method of state observer is also studied;A novel matrix dimension reduction algorithm is designed,according to which an observer-based tension estimation method is proposed,which can effectively monitor tension distribution of the chain drive system and diagnose the fault of the scraper chain.(4)Finally,the study on fault detection for the scraper chain based on the vibration analysis of the middle groove is carried out.The vibration model of the middle groove for the scraper conveyor is established,and then the inherent modal characteristics of the middle groove are studied based on finite element analysis and experimental modal method;According to the modal confidence criterion,the fitness function is established and the optimal placement strategy for sensors based on particle swarm optimization is proposed;A dynamic transmission system model is constructed based on finite element modeling,based on which the transient response analysis of the middle groove under different operating conditions for the scraper chain can be realized;The fault diagnosis method of scraper chain based on the vibration analysis of the middle groove is proposed,which can effectively diagnose fault of scraper chain by means of amplitude analysis and adaptive optimal kernel time-frequency representation.There are 96 figures,9 tables and 195 references in this dissertation.