Study On Design And Dynamic Characteristic Of A New Type Self-moving Orbit Hydraulic Support

In the process of fully coal face production,the follow-up transportation of various auxiliary equipment has become the decisive factor restricting the efficient and safe production of coal mining.However,at present,the transportation of underground equipment trains is mostly the traditional rail winch wire rope traction transportation method,this method needs to lay the track,install the column winch,the operation is complicated,and easy to happen in the work of the track,sports car,wire rope fracture and other phenomena.especially when turning in the roadway,it is necessary to support the stacking support in the coal mine roadway or with the help of auxiliary roadway to realize the equipment train turning and steering,which is time-consuming and labor-consuming,and there are safety risks.Therefore,in view of the disadvantages of coal mine equipment transportation,this paper designs and studies a new type of Self-moving orbit type hydraulic support,which is used as the traction device of equipment train.The support can not only improve the transport rate of coal mine equipment,it can also prevent the bracket from tilting during the movement,ensure the life safety of workers,achieve the purpose of reducing personnel and increasing efficiency.In this paper,the design of Self-moving orbit type hydraulic support structure includes: step structure,lifting support structure,steering structure,anti-roll structure,etc.,and its structural composition is summarized.In order to make the designed support four-link mechanism meet the requirements,the four-link movement trajectory of the support is simulated and verified.The simulation results show that the distance between the front end beam of the support meets the requirement of the four-link support;Then,according to the movement characteristics of the support,the software ADAMS is used to do the dynamic simulation of the support step,and the data curves of the support bottom lifting resistance,ground and track friction,and the thrust of the stepping cylinder are obtained.In order to verify whether the Self-moving orbit type hydraulic support can drive the equipment train to turn and turn in the roadway,according to the Hertz contact theory and the basic theory of multibody dynamics,the model of Selfmoving orbit type hydraulic support driving equipment train to turn and turn in the roadway is established and analyzed,and in ADAMS,the simulation experiments are carried out on the in-situ rotation of the support(turning the head)and the steering of the equipment train in the roadway.The simulation results show that: when the support rotates in situ,base point C is taken as the center of the circle,and the distance between two points A,B and C is taken as the radius to form A semicircular track in the bottom plate,the support rotates in situ only needs to keep the same stroke of the steering cylinder;In the process of driving the equipment train to turn,it is necessary to change the telescopic stroke of the piston rod of the steering cylinder and the stepping cylinder in each step of the steering step to fine tune the direction of the self-moving rail type hydraulic support,the radius of curvature of the trajectory of point B is about 1000mm;When the equipment train collides with the ground anchor,the average collision force is about 60,00 N,and the average speed is about 450mm/s.Considering that the equipment train in the roadway will lead to the bending of the straight line queue for various reasons,using ADAMS to conduct straightening simulation research。 According to the result data curve,it can be known that the Selfmoving orbit type hydraulic support can drive the curved equipment train to return to a straight line.The hydraulic system of the whole machine is designed according to the working principle and analysis and calculation of the Self-moving orbit type hydraulic support.The mechanical-hydraulic co-simulation model of Self-moving orbit type hydraulic support was established by ADAMS and AMESim software,the flow change relationship of the bottom lifting and stepping cylinder under different pressure conditions,and the change of the hydraulic pressure of the bottom lifting and stepping cylinder under the stable pressure are studied.The results show that the stable working pressure of the bottom lifting cylinder and stepping cylinder is 12 MPa and 20 MPa,under the stable pressure,the liquid pressure of the bottom lifting cylinder pressing the track is about 53000 N,which is basically consistent with the data obtained from the mechanical model simulation,and the difference is about 4%.When the Self-moving orbit type hydraulic support is stepping and steering,the key connecting parts such as the ear plate are prone to bend,wear and even damage,and so on,the rigid-flexible coupling analysis can make a prediction in the design stage.According to the theoretical basis of rigid-flexible coupling dynamics,ANSYS and ADAMS were used to carry out rigid-flexible coupling simulation on the support to explore the moving base stress variation under the two working conditions of the support stepping and steering.The results show that the maximum stress of the bottom lifting cylinder seat can reach 350 MPa during stepping,and the maximum stress generated by the contact between the moving base and the track is about 50MPa;During steering,the maximum stress at the hinge of the lug plate of the steering rod is 288.5MPa,and the maximum contact stress between the moving base and the track is about 25.5MPa.through the analysis of the simulation results,it can be seen that the stress changes of the mobile base under the two working conditions are within the yield limit stress range of the materials used,which indicates that the normal and safe work of the support can be guaranteed.In this paper,a new Self-moving orbit type hydraulic support is designed,the dynamic simulation analysis of in-situ rotation and driving equipment train turning in roadway,machine-liquid combination and rigid flexible coupling simulation analysis are carried out,the feasibility and reliability of the support are verified,it is of special significance to study of coal mine safe transportation and efficient production.