Theoretical And Experimental Study On Dynamic Characteristics Of Ring-plate-typed Pin-cycloid Planetary Drive

Ring-plate-type cycloid planetary drive is a new kind of drive developed by analyzing and comparing advantages and disadvantages of involute gear ring-plate drive and traditional cycloid drive, which have of high efficiency, high load-capacity etc. many advantages. It can be used in many parts of engineering field. The study of its static characteristics has reached a high theoretical level, however the study of its dynamic characteristics has just started. There is not any result. So the study of dynamic characteristics on theory and experiment is very importance in this paper.The paper is a part of the project supported by National Science Foundation of China "Double crank ring-plate cycloid drive dynamic response optimization design and experimental research (No.50575030)." Dynamic characteristics are investigated by the method of combining theoretical anlysis and experimental verification based on the comprehensive analysis of development status of ring-plate-type cycloid planetary drive and gear drive nonlinear dynamic characteristics.Modal is the basis of system dynamic characteristic analysis. Vibration response can be pre-estimated on external or internal variety excitation in a certain frequency by this method. Modal analysis of typical parts is done by FEM and experimental methold. In the mean time, FEM. and transfer matrix method are used to analyze and calculate the natural frequency of input axis system, all of which provides a reliable basis for the subsequent dynamic analysis.Meshing stiffness, transmission error and baclash are main internal excitations of gear drive system which are the sources of vibration. The aim of analyzing excitations is to acquaint the causes of vibration. Meshing stiffness models are established by theory of meshing with gap and finite element simulation two methods for analyzing change of meshing stiffness between pin and cycloid and infections of the system parameters on it. Conclusions of that meshing stiffness varies with time has been gotten. Transmission accuracy model is established by kinematio analytic method. Senstivity coefficient curves of rod length are drawn. Infections of senstivity coefficient of rods on transmission accuracy are analyzed. Bearing clearance compensation to rod length manufacturing errors and infections of manufacturing errors on pin-cycloid transmission accuracy are analyzed. Comprehensive computing formula is proposed.Ring-plate-type cycloid planetary drive system will surely vibrate nonlinearly on nonlinear factors, such as time-varying meshing stiffness, transmission error and backlash etc. Nonlinear dynamic characteristics are investigated from nonlinear dynamics perspects. Nonlinear dynamics model is established by considering infections of time-varying meshing stiffness, error and baclash etc. factors. Movement differential equations of system are derived, and these equations are change to non-dimension, which are solved by Broyden method. Infections of damping, error and time-varying meshing stiffness on system vibration amplitude-frequency curves are analyzed.The aim of analyzing nonlinear system is to determine whether the system is stable on the balance position, or to study stability of emerging motion state. Numerical integration method is used to solve nonlinear differential equations with more clearance and more freedoms. Steady-state response is investigated on excitation frequency and error excitation.Vibration and noise of four-plate cycloid planetary reducer driven by two motors are tested by experimental methods.