Study On Natural And Dynamic Characteristics Of Multi-source Driving Cutting Transmission System Of Shearer

As the main equipment of comprehensive mining,drum shearer improves the efficiency of intensive mining and production conditions,and reduces major coal mine safety accidents.As the core part of the shearer,the cutting drive system is mainly responsible for the transmission of cutting power to achieve coal mining.The traditional shearer cutting drive system adopts long chain transmission with multi-stage gears.The gear system is installed in the rocking arm.Because of the limited space,it is difficult to install the frequency converter.The system has some shortcomings,such as long transmission chain,deformation rocking arm and fixed drum speed.When the shearer works in the coal and rock with complex structure,the impact of the drum fluctuates greatly and the load of the drum varies continuously,especially in the case of heavy load sudden change,which results in the low reliability and adaptability of the shearer cutting transmission system.In order to improve the reliability and self-adaptability of shearer cutting transmission system,This article is funded by the National Basic Researsh Progrom(973 project)of China(Grant No.2014CB046304).Based on the invention patent of the shearer cutting drive system power transmission,the natural characteristics,dynamic characteristics and speed regulation and load reduction scheme of shearer cutting transmission system with multi-source driving and multi-stage coupling were studied.Verification of the correctness of the dynamic model and the effectiveness of the speed regulation and load reduction scheme were carried out.The main research contents are as follows:(1)Taking MG300/700 drum shearer as the prototype,the dynamic model of the drum driving system with variable speed and multi-source driving and multi-level coupling was established by using lumped parameter model on the basis of the multi-source driving shearer cutting transmission system designed by the research group.The model was simulated and analyzed through MATLAB/simulink software.(2)Based on dynamics model of the drum driving system,the natural characteristics of the system were analyzed,including natural frequency,mode vector,modal energy,parameter sensitivity,etc.Through the analysis of simulation results,it is concluded that the original multiple-root frequency is fixed and the single-root frequency changes when the multi-stage gear system is coupled;the modal energy reflects the deformation and vibration intensity of the component.Campbell diagram shows that resonance may occur during the low-speed condition of the system.(3)Based on dynamics model of the drum driving system,the dynamic characteristics of the system and the characteristics of speed regulation and load reduction were analyzed.The rotation speed,vibration acceleration and dynamic meshing force between gears of the system under steady state,heavy load abrupt change,impulse and speed regulation are analyzed respectively.It is concluded that the dynamic response of the system is stable under different conditions,and the speed regulation scheme has good performance of load reduction.The sequential speed regulation scheme,which can reduce load,and also ensure the coal mining productivity of the system.(4)Combined with the test bench built in the laboratory,a systematic experimental verification was carried out.The experiment emphatically verifies the dynamic characteristics of the system,including the speed and torque of each component,the adaptability of working conditions and the load-reducing characteristics of speed regulation.The experimental results show that the system has good working condition adaptability and speed regulation and load reduction performance.