Dynamic Characteristics And Experimental Study Of Power Bogie Axle Device Of Tram

As one of the key projects of science and technology support since the eleventh five-year plan,low floor tram has improved the transportation technology of urban rail transit in China and gradually become a common urban rail transit tool.Its advantages include: small space occupied by the track,direct use of existing roads for track laying,and effective mitigation of road congestion.The internal vibration characteristics and noise level of trams are important factors affecting ride comfort,therefore,in operation,it needs to have stable and low noise performance.As the connecting device and driving device of the tram,the axle bridge device of power bogie is placed at the bottom of each section of the car body.The wheels contact the track through the axle bridge device of the motor car.As the connecting device and driving device of the tram,the axle bridge device is installed at the bottom of each car body.Its vibration characteristics are transmitted to the car body through the bogie,and it is the core component that causes the car body to vibrate and transmit noise.Therefore,the research on vibration characteristics and noise of axle bridge device of power bogie has important guiding significance and engineering application value for reducing vibration and noise and improving smooth operation ability of tram.Taking the axle bridge device of power bogie of tram as the research object,this paper analyzes the influence of dynamic excitation on vibration characteristics and noise.The main research work includes:(1)This paper analyzes the axle bridge structure and power transmission route of the power bogie of the tram,establishes the simulation model of the axle bridge of the power bogie,establishes the motion relationship between the wheel and the track according to the offset and rolling motion of the bogie,simulates the wheel gravity restoring force and wheel rail creep force generated in the process of the bogie moving forward,and classifies the track irregularity according to the generation mechanism of the track excitation,so as to improve the stability The time-domain samples of track irregularity excitation are extracted by using the track power spectral density function,and the wheel rail normal force between the tram and the track is simulated based on the time-domain samples.(2)The finite element analysis model of gear pairs at all levels is established to obtain the time-varying meshing stiffness curve,and the bearing bearing stiffness of gear system is solved by using roax.Combined with the internal excitation of time-varying meshing stiffness,static transmission error and bearing bearing stiffness,the bending torsional coupling dynamic model of the gear system of bogie moving axle device is established by using the centralized parameter method.Based on the longkutta method,the dynamic response of gear system and dynamic engagement force of gear pairs at all levels are obtained.(3)Considering the bearing support and gear pair meshing,the finite element analysis model of the power bogie axle and bridge device is established in ANSYS software,and the vibration response of the power bogie axle and bridge is obtained based on the analysis of inherent characteristics.On the basis of modal analysis,the superposition method is used to obtain the vibration response of bogie moving axle device;on the basis of vibration response analysis,the external dynamic excitation is added to study the variation law of vibration response of axle bridge device;the dynamic test of axle bridge device of power bogie is built,compare the test and simulation result to verify the feasibility of the method on the vibration characteristics of the axle bridge device.(4)The acceleration response results of axle bridge device vibration characteristics are taken as data samples to extract the total vibration level of acceleration level structural noise under 1/3 times frequency;the closed surface of EMU axle bridge is extracted,and the sound pressure of field points,namely radiated noise,is obtained by using direct boundary element method in SYSNOISE;the noise test platform of axle bridge device of power bogie is built to collect the structural noise and radiated noise signals and compare with the simulation values to verify the accuracy of the acoustic model.