Virbration And Noise Analysis Of Bridge Crane Reducer Under Complex Excitation And Experiment Study

Bridge crane is an indispensable tool in modern industrial production,which widely used in the factory workshop and the port to lifting tasks.The performance of the virbration and noise of bridge crane directly determines the operation reliability of the bridge crane.With the progress of equipment manufacturing technology,bridge crane reducer is developing towards the direction of high reliavility,light weight and low noise.Therefore,the research on virbration and noise of bridge crane reducer and carry out the source and propagation has important theoretical singnificance and engineering value to reduce the vibration and noise design of bridge crane reducer.The thesis is supported by National Science and Technology Support Project under Contract No.2015BAF06B02.The research on the complex internal excitation and dynamic performance of the transmission system,the simulation analysis and the experimental study of the vibration and noise of the reducer are carried out by using the bridge crane reducer as the research object.The main research work in this paper can be summarized as follows:(1)The geometric model of helical gear with geometric eccentricity has been built to derivate the formula of tooth contact line length and friction excitation,then compare with the helical gear pairs without eccentricity error to research the influence rule of gear with errors.(2)The multi-degree-of-freedom bending-torsion-axis dynamic model which considers the influence of time-varying meshing stiffness,meshing damping,dynamic tooth blacklash,tooth surface error and tooth surface friction is established by lumped parameter method.And the dynamic equation is solved by Runge-Kutta,and the influence of different influencing factors on the dynamic characteristics of the bridge crane transmission system is studied.(3)A parametric finte finite element model of the bridge crane reducer includes transmission system and structural system is estblisted,and the natural frequency and vibration mode of the reducer is calculated by the method of block Lanczos.On this basis,the dynamic response of bridge crane reducer with different eccentricity erroris analyz by mode superposition method,and virbration displacement,velocity,acceleration are obtained.The beidge crane reducer comperhensive performance test bench is build and compared with the calculated value.(4)The structural-borne noise of bridge crane reducer is predicted by Fourier transform and octave processing of the vibration acceleration.The acoustic boundary element model of the reducer housinis constructed by taking the vibration displacement of housing surface as boundary condition,and the surface pressure acoustic pressure on the house and the radiation noise at field point of bridge crane reducer can be obtained by direct boundary element method.Then,the radiated noise values of each field are measured by experiment,and compared with the simulation results.