Research On Kinematic And Dynamic Behavior Of Shearer-scraper Conveyor-hydraulic Support Coupling In Fully Mechanized Mining Fac

The coal mining and transportation of fully mechanized coal mining face are mainly completed by "three machines"(Shearer,hydraulic support and scraper conveyor).The shearer,scraper conveyor and hydraulic support form a complete set of fully mechanized coal mining equipment through mechanical connection and coupling.The shearer carries out the coal mining process.The scraper conveyor is an important transportation device in the coal mining face.The hydraulic support is located on one side of the conveyor in order to provide sufficient and safe working space for workers.As the core component of the scraper conveyor,the middle slot should bear not only the traction and gravity of the shearer,but also the force of the hydraulic support in the mining process of the working face,and the wear is very serious.In order to reveal the dynamic law of the middle slot and the mechanism of the cracking of the upper side of the shovel board,this paper takes one of the middle slots as the research object,and makes a dynamic analysis of the middle slot under the coupling action of shearer,scraper conveyor and hydraulic support.Firstly,the load on the drum when cutting coal and rock is obtained.For straight-line condition and oblique cutting condition,the assembly model of drum cutting coal and rock is established respectively,and the three-dimensional force are obtained by using LS-DYNA software.The virtual prototype of shearer under straight-line and oblique cutting conditions is established respectively.The force of drum are loaded into the virtual prototype under the coupling of shearer and scraper conveyor established by Adams for simulation,and the force of shearer walking wheel,guide sliding shoe and flat sliding shoe on the middle slot of scraper conveyor is obtained.Secondly,under the condition of flat coal and rock floor,the assembly models of the middle groove under straight-line working condition,oblique cutting working condition and sliding working condition are established respectively.The dynamic simulation of the three cases is carried out by LS-DYNA nonlinear dynamic analysis software,and the force of the adjacent middle slot and dumbbell pin on the middle slot of the target and the stress distribution of the middle slot of the target are obtained.The results show that during the walking process of the shearer,the stress at the root of the rib plate of the shovel plate in the middle slot is large,which is easy to wear and crack,which is consistent with the actual work.Then,the assembly model of the target middle slot is imported into ANSYS Workbench for transient dynamic analysis,and the ncode fatigue analysis module is connected for fatigue life analysis.The fatigue analysis results are consistent with the dynamic analysis results of the middle slot.The most vulnerable part is the root of the rib plate of the side slot of the coal shovel board.Then,the main parameters of the coal shovel plate in the middle slot are optimized and analyzed.Taking the thickness and chamfer of the left,middle and right ribs as the main design parameters,the mass of the middle slot,the maximum equivalent stress and the minimum cycle times of fatigue life as the target parameters,the response surface is optimized,and the design points are generated by DOE method,and the sensitivity is analyzed,The most influential factor is the rib chamfer,which is inversely proportional to the target parameter.Through MOGA optimization algorithm,multi-objective optimization is carried out under the condition of reducing the maximum equivalent stress and increasing the quality of the middle groove to a minimum,which makes the middle groove structure more reasonable and improves the service life.Finally,the stress distribution of the side wall of the middle slot coal scraper under the three working conditions is compared.The results show that the instantaneous stress value at the root of the rib extracted under the straight-line condition is the largest,the stress value under the oblique cutting condition is the second,and the stress value under the sliding condition is the smallest.Therefore,the side wall of the middle slot coal scraper is most prone to wear and cracking under the straight-line condition,under the sliding condition,the side groove of the middle groove coal shovel plate is least prone to wear and cracking.Through certain optimization,the stress value is greatly reduced and the service life of the middle groove is improved under the oblique cutting condition.