Design Of Modular Dynamic Simulation Platform Applied To Mluti-stage Planetary Transmission

The planetary gear train which is widely used in machinery, aviation,automobiles, ships and other fields has the advantages of small size, light weight,compact structure, strong bearing capacity.Vibration and noise of the planetarygear train are key factors affecting the system’s reliability, service life andworking environment. Many researches on the dynamic characteristics of thesingle-stage planetary gear train have been done by domestic and foreignscholars and the dynamics study of single-stage planetary gear train is quitemature. In engineering the planetary gear train uses multi-stage or compounddrive for the need of transmission ratio. However study on the dynamics of themulti-stage or compound drive is not many. Simutaneously, space manipulatorjoint uses of the multi-stage planetary transmission mostly, thus doing dynamicssimulation analysis of the manipulator joint will provide guidance for the designof the manipulator joint with excellent dynamic properties.This paper develops a modified torsional model of multi-stage planetarygear train using the lumped parameter method. Meshing stiffness, damping,friction, backlash and planetary bearings supporting stiffness factors areconcerned.Based on the modular method, four modules are established.Themulti-stage planetary gear train’s nonlinear dynamical differential equations aregenerated automatically by calling the four modules.This paper studied the inherent characteristics of the multi-stage planetarygear train based on the modular method. Mass and stiffness matrixes are dividedinto three modules respectively: the carrier module, the sun gear module and theplanetary gear module. This paper developed the program to calculate theinherent characteristics which including natural frequencies and vibration vectorsand then calculated the natural frequencies and vibration vectors of the four stageplanetary gear train which is used in the joint of space manipulator. Threevibration modes of the multi-stage planetary gear train are got by summarizingthe vibration vectors. And natural frequency sensitivities to system parametersare rigorously investigated.The dynamic characteristics of the multi-stage planetary transmissionsystem were analyzed. The dynamic response of the power train was solved bythe numerical analysis method. In order to verify the applicability andavailability of the modular designed model, the calculation results of modular designed model and integral designed model were compared.Based on the above research, a logic flow chart of multi-stage modularsimulation platform applied in the planetary gear train’s dynamics researches wasdrawn. This paper developed a modular simulation platform using MatLab,which used in dynamic studies of the multi-stage planetary gear train. Theprototype’s applicability and feasibility was verified by using a four stage2K-Hplanetary gear train as an example.