Dynamic Modeling And Response Analysis Of The Spur Gear With Pitch Error And Spalling Fault

Gear transmission mechanism has the advantages of low transmission loss,wide range of speed ratio,high power density and stable working performance,etc.,and is an indispensable part of mechanical equipment.The working environment of the gear system is complex and the operating condition is bad,which lead to the faults such as pitting,gluing and tooth breaking,and eventually result in the failure and destruction of the gear system.Monitoring the dynamic response of the gear system and identifying and diagnosing the early failure of the gear system are the keys to prevent the failure of the gear system.However,the manufacturing and installation errors of the gear system will interfere with the dynamic response characteristics of the early faults and hinder the early fault diagnosis of the gear system.Therefore,it is of great academic value and engineering significance to study the influence law of manufacturing and installation errors on the dynamic response characteristics of early faults for gear system fault diagnosis.Pitch error is a kind of manufacturing error,and tooth surface spalling fault is a typical gear tooth fault.On the one hand,the tooth pitch error will cause uneven loading of the gear,which will aggravate the fault of tooth surface spalling;on the other hand,it interferes with the dynamic response characteristics of early spalling faults and hinders the early spalling fault diagnosis of the gear system.At present,the study on vibration characteristics of spalling faults has not considered the influence of tooth pitch error.For the problem of unclear changes in the dynamic response characteristics of the gear system coupled with pitch error and spalling faults,this paper has carried out research in the aspects of spalling fault meshing stiffness excitation,pitch error meshing stiffness excitation and multi-fault coupling gear dynamic modeling,etc.,and analyzed the dynamic response characteristics of the gear system under the coupling effect of pitch error and spalling fault.The major contents of this paper as follows:(1)For the problem of the random distribution of gear meshing stiffness excitation caused by tooth pitch error,an iterative model of gear meshing stiffness considering tooth pitch error and a calculation method of gear meshing stiffness excitation were proposed.Analyzing pitch error for no-load static transmission error of the geometric mapping,based on the static light transmission error and tooth deformation geometrical coordinate relations,considering the changing load distribution among gear teeth of gear Hertz contact stiffness,calculating the influence of different parameters of single tooth pitch error and pitch error on gear meshing stiffness,the influence of pitch error of gear meshing stiffness was obtained.(2)For the problem of unclear dynamic response characteristics of early spalling faults in the gear system,the coupling dynamics model of gear considering the tooth pitch error and the excitation calculation method of meshing stiffness of the spalling fault were proposed.Considering the effect of spalling fault on the gear meshing stiffness and tooth deformation,comparing the influence of spalling fault size on the excitation of gear meshing stiffness and the dynamic response of the gear system,and the dynamic response characteristics of the gear system with early spalling fault were obtained.(3)For the problem that the mechanism of the influence of the tooth pitch error on the dynamic response characteristics of the early spalling fault of the gear system is unclear,considering the influence of gear precision on the distribution of gear pitch error,coupling the impact pitch error and spalling fault on the excitation of gear meshing stiffness,the interference characteristics of the early spalling fault dynamic response characteristics of the gear system were obtained by the dynamic numerical solution.(4)The dynamic transfer errors of the normal gear system and the peeling gear system under different working conditions are analyzed by comparing the simulation and the experiment.The experimental parameters and working condition data were input into the dynamic model proposed in this paper,and the differences between the experimental data and the simulation results were compared and analyzed to verify the accuracy of the dynamic model proposed in this paper.