Study On Dynamic Characteristics Of Coal Rock Crushing By Disc Cutting Mechanism

In order to obtain the dynamic characteristics of dish-disk cutter vibration crushing coal and rock,the dish-disk cutting mechanism proposed by our research group under different parameters was studied from theory,simulation and experiment respectively.Through the analysis of the effect of disc cutters with the coal and rock,building the coal and rock vibration box disc cutter three-degree-of-freedom system dynamic differential equations and kinetics by calculating the shaft stiffness is too large to body is affected,it is simplified to the excitation system two-degree-of-freedom dynamics equivalent model of coal and rock under different parameters was deduced disc cutters with the coal rock,the expression of the amplitude;When increasing the excitation system stiffness and frequency,the amplitudes of disk reach the maximum value and then decrease gradually.The amplitude of disc increases obviously when the thickness of eccentric block increases.The single-degree-of-freedom dynamic model of the excitation system is established.The natural frequency increases with the increase of the stiffness,and the amplitude variation of the disk is consistent with the two-degree-of-freedom dynamic equivalent model of the excitation system-coal rock.The variation of amplitude and natural frequency of disk under different excitation system stiffness,excitation frequency and eccentric block thickness is analyzed in ADAMS,and the conclusion is consistent with the theoretical analysis.The ADAMS and EDEM Co-simulation model of disc cutting mechanism was established,and the load of disc cutter in EDEM under different working conditions was transmitted to ADAMS in real time for dynamic simulation of mechanism when crushing coal and rock.The greater the amplitude of disc,the higher the excitation frequency and the thicker the eccentric block,the greater the mean axial load and the smaller the mean radial load.When the excitation frequency is less than the natural frequency and the excitation frequency remains unchanged,and the eccentric block thickness remains unchanged,the larger the coal rock parameter,the smaller the disk amplitude.The experiment was carried out by the disc cutting mechanism test bench,and the no-load test was carried out by changing the frequency and thickness of eccentric block.The amplitude variation rule of the disc was consistent with the theory and simulation.When the cutting test is carried out when the excitation frequency is changed,the mean value of the radial load of the disc cutter has the same variation law as the mean value of the simulation load.Eccentric block replacement mechanism,disk amplitude and eccentric block thickness is proportional to;Due to the limitation of the test system,the improved design of the test bench was carried out for the factors such as large offset and uncontrollable amplitude when the disc cutting mechanism crushed coal and rock.The dynamic characteristics of disc cutting mechanism were studied through theory,simulation and experiment.The research has reference significance for the parameter selection of coal and rock crushing,and provides a theoretical basis for the improvement of new disc cutting mechanism.