Research On Failure Mechanism Of Middle Trough Slot In Shearer Linear Cutting Condition

China is the largest energy consumer in the world.Although China advocates clean energy and secondary energy in recent years,coal still occupies a dominant position in energy consumption.The average annual coal mining volume is still over 3 billion tons,which provides a strong guarantee for the country's economic construction.Large-scale coal mining benefits from modern coal machinery and equipment,especially the extensive application of fully mechanized mining equipment.Shearer,scraper conveyor and hydraulic support as the core of fully mechanized mining equipment,their performance directly affects the efficiency of coal mining.Scraper conveyor is one of the significant parts of three machines in fully mechanized mining face,and the middle trough is an important part of scraper conveyor,accounting for more than 70% of the total quality of scraper conveyor.The middle trough is not only the track of shearer operation,but also the carrier of material transportation.In the complex and changeable mine environment,the middle trough has become one of the most vulnerable parts of scraper conveyor.There are tens of thousands of middle troughs that fail every year in our country,which not only seriously affects theefficiency of coal mining,but also leads to serious waste of resources.The failure modes of the middle trough are various,mainly the wear of the chute side and the cracking failure of the shovel plate,the convex and concave end of the dumbbell pit and the pushing ear.In this paper,the cracking problem of the ramp plate in the middle trough is analyzed and studied,and the stress of the middle trough under the condition of straight cutting of shearer is analyzed by using finite element analysis software.Firstly,dynamic finite element software is used to simulate and analyze the front and rear drums cutting coal wall under the condition of straight cutting of shearer,and obtain the three-dimensional force on the front and rear drums.Using ADAMS multi-body dynamics software,the virtual prototype model of shearer cutting coal wall in straight line is established.The three-dimensional load of the drum was applied to the center of mass of the front and rear drum of the virtual prototype,and the simulation analysis of the prototype was carried out to obtain the load-action curve of the Shearer to the middle trough,which provided the load basis for the mechanical analysis of the middle trough.Secondly,ANSYS/LS-DYNA finite element software is used to analyze the static and dynamic characteristics of the middle trough,observe the stress distribution of the middle trough under this working condition,and analyze the failure reasons of the middle trough.At the same time,through simulation,the influence of incomplete coal and rock floor on stress distribution and stress magnitude of the middle trough side is studied.Finally,the multi-objective driving optimization module in the finite element software is used to optimize the size of the middle trough,and the fatigue life analysis software is used to analyze the fatigue life of the middle trough before and after optimization,which proves the accuracy of the optimization results.