Analysis And Optimization Of Vibration And Noise Of New Energy Bus Transmission

As the global energy crisis and environmental pollution problems become more and more serious,new energy vehicles will become the mainstream and trend of the future development of the automobile manufacturing industry.As an important part of the power and transmission system of new energy vehicles,the gearbox is also one of the main noise sources of new energy vehicles.Therefore,optimizing the structural vibration and noise characteristics of new energy vehicle gearboxes is crucial for the application and vigorous development of new energy vehicles.This article takes a single planetary gearbox applied to a pure electric bus as the subject of research,and optimizes the NVH performance of this single planetary gearbox as the research goal.Through the use of professional multi-body dynamics simulation analysis software,Finite element simulation analysis software and acoustic simulation analysis software,etc.,perform vibration and noise simulation analysis of the single planetary gearbox structure,and optimize the structure of the gearbox body according to the simulation analysis results to improve the vibration and noise of the gearbox characteristic.The main research contents and results of this article are as follows:1.Through dynamics simulation and application software Adams,a simulation motion model based on gearbox gear meshing transmission system is established.After simulation and analysis,the speed of the main transmission member and the gear meshing force between each gear pair are obtained,and the The theoretical values ??of the gear meshing force calculated by the classic mechanical design formula are compared to verify the correctness of the simulation model of the gear meshing transmission system and the simulation results.Finally,the simulation obtained the dynamic support force between the bearing seats on the gearbox.2.Use the finite element software Hypermesh to build a finite element model of the single planetary gearbox box,constrain the box according to the actual working conditions of the gearbox,and do modal analysis to solve the problem,thereby obtaining the natural frequency and mode of the box Mode shape.The dynamic response of the gearbox bearing seat is used as the vibration excitation to simulate the vibration response of the gearbox.Through the analysis of the simulation data,the surface vibration acceleration of the gearbox body is obtained.3.Based on the acoustic principle and the boundary element calculation method,theacoustic radiation software LMS.Virtual.Lab is used to establish a cabinet radiation noise simulation model integrating the cabinet structure grid,acoustic grid and field point grid.The vibration acceleration on the surface of the box structure is the boundary condition.Acoustic simulation of the gearbox results in the sound pressure level and the noise power level of the box structure.4.The optimal structure design of the vibration reduction and noise reduction of the transmission box structure is added.The free damping structure and the reinforcing rib structure are added to the box body.The thickness of the base layer structure,the thickness of the damping structure and the height of the reinforcing rib are used as design variables.Using the ks function and response surface calculation method,an optimized model of vibration and noise reduction based on the vibration acceleration level of the gearbox case surface is established.The sequential quadratic programming method was used to solve the cabinet optimization model,and an ideal optimized structure for gearbox vibration and noise reduction was obtained.The optimized cabinet rigidity was improved,and the cabinet sound power level and surface sound pressure level were reduced The feasibility of the optimization scheme in this paper is verified.