Fault Diagnosis Of Planetary Gear Train Based On Improved Energy Method Modeling

Along with drastic progress of machinery field,planetary gearbox plays an prominent role in the fields of automobile,aerospace,transportation,energy,power generation and precision instruments.Planetary gear has a variety of structure forms,and can vary with the different volume sizes of application fields.It has strong applicability and high transmission efficiency,which can greatly improve the operation capacity of mechanical transmission system.Application fields are different,resulting in the planetary gearbox working environment is also very different,the occurrence of a variety of faults,once the failure will directly affect the effective operation of the whole transmission system,so the planetary gearbox fault diagnosis is more necessary.In this study,the planetary gear is regarded as the object of study,and the stiffness excitation based on the dynamic model is studied.Improved energy method and finite element method are used to calculate and analyze the sudden change of meshing stiffness under different damage modes.Through the dynamic response of planetary gear box experiment,the fault index is analyzed.In the first instance,this paper present the research significance and background.Introduces the research status of planetary gearbox fault diagnosis in the aspects of signal processing,intelligent diagnosis,model dynamics,and put forward the research strategy of this paper.Then,the dynamic foundation of the planetary gearbox is expounded,and the input meshing stiffness excitation of the system is studied.Firstly,according to the transmission mechanism of the gear,the physical model of the equivalent cantilever beam based on the tooth root circle was established.According to the improved energy method,considering the energy stored in the gear,the stiffness components of the gear were obtained by integral variation,and the mathematical model was established by numerical calculation of each meshing stiffness.For the damaged tooth,the geometric parameter changes caused by the damage are introduced and the same numerical calculation is performed.At the same time,according to the size of the solid model measured from the laboratory,Solid Works was used to complete three-dimensional modeling,and Workbench dynamics module was used for simulation analysis.The models of normal teeth and damaged teeth were established through Solid Works,and the finite element software was imported,and the time history changes were taken as reference.The variation of force and deformation in the meshing process is obtained.Based on the theoretical basis of finite element method,the variation of stiffness under this method is obtained through further calculation.Finally,an experimental platform for fault diagnosis of planetary gearbox was built.A speed and load were selected to collect vibration signals of normal teeth,planetary gear cracks and wear conditions,and a reasonable method was selected for data processing.Combined with the analysis of stiffness mutation of theoretical calculation and simulation,a new idea was provided for fault diagnosis.