Study On Mechanical Characteristics And Reliability Of Scraper Chain Drive System

Scraper conveyors have the characteristics of smooth operation,simple structure and continuous transportation.It is an essential transportation equipment for fully mechanized coal mining face.The operation of scraper conveyor will directly affect the economic benefits of coal production.As the key component of the scraper conveyor traction mechanism,the reliability of the scraper chain plays a decisive role in the failure-free operation of the scraper conveyor.At present,with the continuous development of the coal mine in the direction of deep and large-scale,the requirements on the reliability of scraper conveyors are becoming higher and higher.Therefore,in this paper,the dynamic characteristics and reliability of scraper chain drive system are studied by combining theory,simulation and experiment to provide guidance for ensuring efficient and safe transportation of coal resources and extending the service life of scraper chain drive system.Taking scraper chain transmission system and its related parts as the research object,the contact mechanics between chains,the meshing principle of chain wheel and chain and the peed of scraper chain transmission were analyzed from the theoretical calculation.The maximum contact stress between the chain rings and that between the sprocket and the chain ring are obtained,and the stably meshing conditions of the chain rings were deducted.Then,the dual drive coupling motion model of the scraper chain transmission system was established by combining the finite element theory.Based on the rigid body dynamics model of scraper chain drive system,the dynamic characteristics of scraper chain drive system under different output powers,working inclinations,setting lengths and that when the chains were blocked were simulated by ADAMS separately.The results of the influence of different factors on the mechanical properties were obtained,and the correctness of related conclusions has been confirmed by the experiments.In order to further analyze the mechanical properties of the system,the contact mechanics characteristics between chain rings and that between sprocket and chain ring under chain jamming condition were analyzed by ABAQUS,and the nonlinear dynamic characteristics of scraper system under different working conditions were analyzed.The main positions of the stress concentration of the sprocket and the chain ring were obtained,and multiple collisions occurred between the link and the scraper in the start-up stage.When the system runs smoothly,the maximum equivalent stress value of the scraper is divided into two stages: rising and stabilizing.The running speed only affects the duration in which the maximal stress value of the scraper reaches the stable stage under smooth running condition.Based on the analysis of the mechanical characteristics of scraper chain drive system,in order to improve its reliability,the conclusion was obtained that when the scraper chain system transported brown coal,coking coal,anthracite and gangue,the service age of the ring chain was mainly concentrated in the range of 0-19 months,0-15 months,0-10 months and 0-5 months separately through the simulation analysis on the service age of the scraper chain system.Through the analysis of the best maintenance period of scraper chain transmission system,the conclusion was obtained that the best maintenance period of scraper chain transmission system was 5.5 months,3 months,2 months and 1 months when transporting brown coal,coking coal,anthracite and gangue separately.