Research About Rational Match Of Parameters And Dynamic For Gear System

Gear transmission is one of the most extensively applied mechanical transmission. Dueto the existence of tooth side gap, shaft side gap, time-varying meshing stiffness, syntheticmeshing error and so on, gear system dynamics behavior has a wealth of nonlinearcharacteristics. Compare to normal gear transmission, planetary gear transmission has greaterratio of power to weight and higher transmission ratio. It also has more trouble of vibrationand noise for its complex structure.The article takes two-stage gear transmission system and Ravingneaux compoundplanetary gear train sets as the research object.Considering the main factors affecting the geartransmission system,then established two-stage gear transmission system and Ravingneauxcompound planetary gear train sets model separately,and has carried on the numericalsimulation,by numerical simulation on the response of the system we get bifurcation map,maxlyapunov index figure,maximum dynamic load diagram,impact of state diagram,phase,timedomain wavefore,dynamic load coefficient diagram.Based on the results of numerical simulation, the bifurcation characteristics of the systemand the vibration of the system in time domain and frequency domain features are studiedwith nonlinear theory method. Analyse the influence of various parameters on the systemvibration characteristics and the associated relationship, the basis of parameters selection andoptimizing interval of the parameters are given. The results show that: the system showsabundant dynamical behavior with the change of excitation frequency, as the existence ofnonlinear factors such as backlashes,"jump" and "crisis" of nonlinear system dynamicsbehavior emerge in the system, and "jump" and "crisis" are the main factors of the change ofthe dynamic load between the gear pair, they can also cause a shock state changes sometimes.The system will tend to periodic motion with the increase of external load. From the view ofchaos control, the increase of external load can effectively control chaotic motion.Time-varying mesh stiffness and damping are also major nonlinear factors of the system, in agiven parameter range, the larger the stiffness is, the smaller the damping is, the easer thechaotic motions emerge. Chaotic motion is harmful in mechanical system, so the dynamicdesign of the gear system should avoid the chaotic motion area. General transmission errorsare the deviations of actual location and ideal location, when the gears in the manufacturingand installation inevitably. These deviations are harmful to gear system, should be to avoid asmuch as possible. To comprehensively consider the periodic motion state, the maximumdynamic load and impact between the gear pair of the system, a working range under certainparameter of the system is obtained in this thesis. Gives the optimal selection scheme and interval of the meshing stiffness, damping and backlash, which provides a theoretical basis forthe dynamic design of the gear.