Analysis Of Vibration And Research Of Reducing Vibration About The Electric Equipment Box In Roadheader

The roadheader in the subject belongs to the high power roadheader in hard rock conditions.When the roadheader is cutting coal and rock,strong impact loads cause obvious vibration of the electric equipment box,make operating reliability of electrical components inside down and affect the normal work of the machine.The reduction of vibration about the electric equipment box is generally based on a single rubber vibration isolator or wire rope vibration isolator for vibration isolation.For this kind of vibration isolation system,it is suitable for wide frequency of vibration,but the vibration isolation effect is not good,and doesn’t work for high frequency.In order to investigate vibration characteristics of the electrical equipment box in Longitudinal roadway roadheader,taking a domestic EBZ300 roadheader as a example,three-dimensional solid model of Longitudinal roadway roadheader was set up by using UG.On the basis of mechanics model and formula of single pick,the load of the roadheader pick in the cutting head was calculated when the roadheader cut transversely.However,when the roadheader is drilling,the load of the roadheader pick in the cutting head was obtained through the simulation on drilling rock in the ANSYS-DYNA software operating environment.The load of roadheader pick was added by using IF function when the roadheader cut transversely and by SPLINE function when it is drilling.The simulation in two kinds of working condition was carried out in the Adams/view software operating environment.Comparing with the measured vibration signal in electric equipment box,the frequencies affecting greatly the overall performance of the system were determined.Amplitude in y axis direction is higher than X and Z axis direction in a transverse cutting conditions.Vibration peak in x,y,z axis direction is in two frequency domain section that one locates within low frequency section which is under 25Hz,and the other locates within high frequency section which is between 110Hz and 120Hz.In drilling conditions,because impact load along the direction of the body was stronger than other directions,amplitude in Z axis direction is higher than X and Y axis direction in the electric equipment box.The results provided a foundation for the further design of a dynamic vibration absorber to reduce the vibration of the greatest influence to vibration direction.Then,a kind of passive dynamic vibration absorber which is used in the electric equipment box of the roadheader on the basis of the original rubber absorber was used to study.The electric equipment box and dynamic absorber constitute a master-slave system to realize the vibration energy transfer from the primary system and achieve the purpose of inhibiting the primary system vibration.The natural frequency and modal analysis were calculated on the machine,and mechanical system that it is composed of the electric equipment box and dynamic absorber was set up.According to the measured vibration signals of electric equipment box,system performance was evaluated by using Matlab/simulink software.The simulation results were analyzed in the time domain and frequency domain,it provides theory for the design of dynamic vibration absorber which is used to reduce the vertical vibration of electric equipment box.