Design And Implementation Of Self-moving Conveying System For Open-pit Coal Mining Kinetic Realization

Due to the irregular shape of the mine field and the small size of the stope area,a large number of side walls are pressed and the secondary mining is more difficult in open pit coal mining,resulting in serious loss of coal resources.At present,some open-pit mining enterprises try to use continuous coal mining machine supporting transfer conveyor for side coal recovery operation in Inner Mongolia mining area,so that the side coal crushing coal has been greatly recycled.However,the transfer conveyor itself does not have the function of self-travel,which requires continuous shearer traction,and there is a problem of insufficient walking power.In addition,when moving the working face,a large amount of manpower and material resources are consumed.These problems seriously restrict the improvement of the coal recovery efficiency of the side help.There is an urgent need to develop conveying equipment that can solve the above problems.In view of the above technical problems,according to the design theory of crawler chassis,belt conveyor design theory and functional requirements,this paper has designed a new type of self-moving transportation system for side coal mining.The equipment includes a walking slewing system,a material transportation system and a slip steering The system has the functions of reprinting,transportation and walking.It adopts the crawler walking mode and advances and retreats with the continuous shearer to complete continuous transportation.Three-dimensional models of three major systems were created using Solid Works software,and assembly design was carried out.Finally,the construction of a virtual prototype model of the self-moving transportation system was completed,and simulation objects were established for dynamic simulation.In order to solve the problems of coal residue,coal sprinkling,serious loss of conveyor belt and chute wear during the conveying process of the material conveying system,EDEM is used to simulate the conveyor's bulk trajectory and compare and analyze the bulk trajectory drawn by the calculation method.The installation position of the chute is determined.Through the comparison and analysis of the two types of chute,linear and linear plus circular arc,the rule of the influence of the geometry of the chute geometry on the vertical and horizontal speeds of the material at the outlet of the chute is discussed,and the best plan is found to let the material at the outlet of the chute.The horizontal speed at the location is close to that of the conveyor belt,and the vertical speed is reduced as much as possible to reduce the wear of the conveyor belt.Through the wear analysis of the chute,the wear position of the collision between the material and the chute is determined.In order to prevent the chute wear from seriously affecting the reprinting of the material,replaceable wear plates are installed at the main wear position.In order to meet the needs of the walking system to adapt to various complex road conditions,ensure that the self-moving transportation system can move independently in the mining chamber of the side.The crawler walking theory was used to calculate the running resistance,traction and adhesion of the crawler shoe walking system.Recurdyn combined with Solid Works was used to reconstruct the multi-body dynamic model of the side coal mining self-moving transportation system.A simulation analysis of the motion characteristics revealed that the transportation system had a large inertial resistance when it started.The torque of the crawler drive wheels was 3655 N·m when the vehicle was running at full load in the chamber,and the torque of the crawler drive wheels when the load was withdrawn from the chamber was 2695 N·m,the torque of the crawler drive wheels when rotating in place is 8750 N·m,and the torque of the crawler drive wheels during low-speed straight-line climbing is 8436 N·m,which provides data reference for the design of the walking mechanism power system.In addition,comparing the driving wheel torque under the forward and backward climbing modes,it is found that the driving wheel torque in the forward climbing mode is periodically changed,and the torque change is more stable.Aiming at the problem that the self-moving transportation system will generate vibration and affect the normal use of the whole machine during walking and material transportation.In this paper,the modal analysis theory is used to analyze the natural frequency and vibration mode of the free mode of the conveyor truss and the constrained mode of the whole conveyor system.It is found that the first-order natural frequency of the truss is close to the excitation frequency generated by the conveyor idler.In order to prevent resonance,the truss structure is optimized,the channel steel is transformed into rectangular steel,and the optimized first-order natural frequency of the truss is increased from 8.67 Hz to 11.16 Hz,to avoid the excitation frequency generated by the rotation of the idler,and the amplitude of the truss is reduced after the modification;The connection method between the truss and the track chassis was changed from ball hinge to pin connection to improve the connection rigidity.The first-order natural frequency of the constrained mode of the whole machine was increased from 5.3 Hz to 10.5 Hz,and the fourth-order natural frequency was increased from 23.1 Hz to 31.2 Hz.The natural frequency of the order is increased from 25.3 Hz to 37.7 Hz,avoiding the excitation frequency generated by the idler and drive motor,and the amplitude of the whole machine is reduced after the transformation.This paper designs and develops a self-moving transportation system for open-pit side coal mining,analyzes the discharge trajectory of its conveyor and designs a transfer chute,simulates and analyzes the dynamic characteristics of its track shoe walking system,and uses modal analysis Analyze the dynamic characteristics of the self-moving transportation system,and design a stable and efficient self-moving transportation system,which is of great significance for improving the mining and recovery of the side coal.