Research On Vibration And Noise Of The Gearbox System Of The Pruning Machine

Pruning machine is an important tool in landscaping work,which can greatly improve the pruning work of garden workers.However,the traditional design method to consider the appearance and strength of the pruner,and ignore its dynamic characteristics,so that the products produced by the vibration noise is too large,to the garden workers' physical and psychological caused great harm.Gearbox is the key transmission parts of the pruner,the design and manufacture of the lack of gear box vibration will cause severe,resulting in greater radiation noise.In this paper,the gear box system of a model garden pruner is taken as the research object,and its vibration characteristics and the noise are studied.The aim of this paper is to improve the vibration noise of the gearbox system by improving the structure.This paper analyzes the vibration and noise of the gearbox system of the pruner as follows:(1)Extraction of Excitation Force of Trimmer Gearbox.Using the powerful modeling function of SolidWorks SolidWorks,the 3D CAD model of the pruner gearbox is established,the necessary simplification and deletion are carried out,and the obtained gearbox gearbox structure is imported into ADAMS.Based on the theory of multi-rigid-body dynamics,combined with the actual movement of the trimmer gearbox,the motion constraint and contact parameters between the parts are set,and the multi-rigid body dynamics model of the gearbox transmission system is established.The driving process of the pruner gearbox is simulated and the meshing force of two pairs of meshing gears in the gear box box is extracted.(2)modal analysis and experimental verification of the pruner gear box.The establishment of the finite element model is the basis of the modal analysis.First,the CAD model of the pruner gearbox is pre-processed by Hypermesh.Then,according to the geometric characteristics and size of the gear box,the grid standard,The finite element modelof the gear box is established.Finally,ANSYS Workbench is used to calculate the constraint mode and free mode of the gear box structure,and the modal mode is obtained by the constraint modal analysis.In addition,through the force hammer method to hit the gear box to get the frequency response curve,based on frequency response curve extraction test mode frequency.The experimental free mode of the pruner gearbox is compared with the simulated free mode,and the modal frequencies are consistent,and the correctness of the finite element model is verified.(3)Analysis of Harmonic Response of Trimmer Gear Box.The meshing force of the gearbox gear obtained by the above is used as the excitation to load the finite element model of the gear box gear box,and the vibration response of the gearbox is obtained,and the vibration response is obtained at each frequency,and the key reference is obtained by ANSYS Workbench Point X,Y,Z direction of the vibration displacement data,analysis of its vibration characteristics.(4)Prediction of Radiation Noise of Trimmer Gearbox.The acoustic finite element model of the pruner gearbox is introduced into the LMS Virtual lab,and the vibration results of the pruner gearbox are mapped to the acoustic grid as the boundary condition of the radiation noise analysis.The FEM(Finite Element Method)and AML(Automatic Matched Layer)method to predict the noise of the pruner gearbox.(5)Optimization and improvement of radiation noise of trimmer gearbox.Firstly,the harm of noise to human is introduced,and then the symmetrical stiffeners are added to the box under the gear box according to the simulation results.The modified model is reconstructed and analyzed based on ATV(Acoustic Transfer Vector)and MATV(Model Acoustic Transfer Vector)Theory,the use of FEM and AML method to predict the box structure optimized after the radiation noise,noise reduction effect is obvious.