| During the work of the shearer,due to the complicated and changeable coal seam conditions,the cutting department will encounte rvarious unexpected situations when cutting the coal seam.The abrupt load causes the vibration of the cutting section of the shearer.It will causes impact of hydraulic system,Vibration will have impact effects on the cylinder,which will affect the stability of the hydraulic system and increase the reliability of the cylinder.This will reduce the service life of the cylinder and affect the efficiency of the shearer.In the cutting section of the shearer,the height-adjusting cylinder is the working device of the hydraulic system of the shearer,and at the same time plays the role of supporting and heightening the cutting section.The height adjustment of the shearer is the most critical working mechanism in the height adjustment section of the shearer.The working efficiency of the increase cylinder directly affects the working efficiency of the shearer.Therefore,the research content of this paper is proposed based on the above discussion.(1)Selecting the main cutting state of the shearer and analyzing the working status of the cutting section of the shearer and obtaining a mathematical model of the force acting on the spiral drum.According to the analyzed shearer model,get the three-way resistance of the shearer during working,and established the force model of the lift cylinder under the load of the roller.Simplify the model of the height-adjustment mechanism of the shearer and establish a mathematical model for the vibration of the cutting section.By this model,The vibration of the cutting section has a great influence on the height adjustment cylinder of the shearer.(2)The 3-D model of the Shearer cutting section was established by the software Pro/E,the virtual model was imported into the dynamics software ADAMS to establish the dynamic model of the cutting section,and the impact situation of the cylinder was analyzed under the vibration of the Shearer cutting section.The three-direction step load and the three-direction sinusoidal load were applied to the spiral drum respectively for analyz the vibration of thecutting part of the shearer.The center of the rocker arm and the head of the cylinder piston rod were selected as the analysis point to observe the vibration.According to the simulation results,the main direction of the vibration of the rocker under the action of step load and sinusoidal load is the direction perpendicular to the ground and the direction parallel to the fuselage,where the step load on the spiral drum will affect the cylinder.The head of the piston rod creates a huge impact load.(3)In the work of the shearer heightening cylinder,the cylinder rod chamber and the rodless chamber are filled with hydraulic oil.When the two-chamber check valve of the hydraulic cylinder is locked,The oil cylinder is deformed by the action of the impact load,which in turn affects the movement of the hydraulic oil.The change in the movement of the hydraulic oil acts on the cylinder of the hydraulic cylinder.Coupling between liquid and solid.Therefore,the fluid-solid coupling model of the cylinder was established through ANSYS,and a comparative cylinder model was established to study the working characteristics of the height-adjusting cylinder under impact load.The analysis results show that under the same impact load,Compared to the original height-adjusting cylinder,when subjected to the same impact load,the cylinder's stress should be changed little,and the hydraulic oil column's deformation is reduced.The vibration amplitude of the internal pressure decreases,and the time for restoring stability becomes shorter.Compared with the original cylinder,the pressure fluctuation of the newly selected cylinder is reduced when the impact is applied,thereby increasing the life of the cylinder and reducing the damage to the cylinder caused by the impact.The research of this paper can provide guidance for the manufacture and selection of the sheraer cylinder. |
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