Study On Dynamic Characteristics Of Two-step Coaxial Dual-ring Gear Reducer

Ring reducer is developed very quickly in recent year due to its features such as its simple and compact structure, high driving ratio, large loading capacity and high driving efficiency. But some problems, including great noises, high temperature and the early-worn of bearings occurring under the condition of high-speed operation, heavy loading and high transmission ratio, influenced seriously its popularization progress and are urgent to be solved.Based on the study of driving principle of current ring reducer, this dissertation suggested a two-stage coaxial double-ring reducer in the purpose of solving the high vibration and noise problems of ring reducer under the condition of high-speed and heavy-load operation, which consists of one-stage cylindrical gearing and one-stage dual-ring gearing. Bases on the analysis of the transmission theory, kinematics, dynamics of the suggested reducer, the author designed and manufactured a prototype of the suggested reducer, made some relevant researches and got a satisfying result. The major research works in the paper are listed as follows::(1) Provided a new-structured ring reducer, i.e. two-stage coaxial dual-ring gear reducer, set up its three-dimension model and assembled the model in the virtual condition, analyzed the structure and forces bearing situation of the new reducer and simulated the forces bearing situation using ADAMS software.(2) Calculated the contact stress of the inner meshing of the dual-ring reducer by means of finite elements method, and learned the maximum stress value and the actual pairs of contact teeth, which became a reliable source for selecting geometry parameter of reducer;(3) Set up the Fern model of parts and coupling system of the reducer, based on which, analyzed the mode of the ring-like plate, the eccentric axis, the gear box and obtained top 10-rank inherent frequency and vibration mode as well as the top 20-rank inherent frequency and vibration mode of coupling system;(4) Calculated the inner excitation of gear resulting from varying stiffness and error of gear, analyzed the response of the system by means of vibration superposition method based on coupling system mode, and predicted the dynamic response of the dual-ring reducer under dynamic inner excitation, and made a broad study of the dynamic characteristics of the reducer;(5) Designed and manufactured a prototype and tested practically its efficiency and the dynamic characteristics on gearing system dynamic experiment desk. The test result indicated that the two-stage coaxial double-ring reducer reached an efficiency of 96% and is improved on the vibration.