A Study On Loading Capacity Of Three-ring Gear Reducer And Design For New Product Series

This dissertation is aimed to design a new product series for three-ring gear reducer. The research work involves Elastic Meshing Effect analysis and choice for modification coefficients of internal gear pair, which are completed by my colleagues Ying guangchi and Yu yuehai respectively. Three-ring gear reducer is a type of planetary transmission device with small tooth difference, which has numerous advantages such as large transmission ratio, high loading capacity, compact volume and simple structure etc. And it has been widely used in many fields because of its advantages over traditional reducer. Three-ring gear transmission is an over-constrained mechanism and its loading state is quite complicated. In this dissertation the elastic deformations of three-ring gear reducer are analyzed to derive the coordinate relation between them. Based on the analysis an elasto-static model is established to get the specific loading state of three-ring gear reducer. The elasto-static model includes deformations of input and support shafts, gears, planetary bearings and support bears on output shaft. When bears enough loading, actual contact tooth number will exceed theoretic contact tooth number, which makes the loading capacity of the gears increased dramatically. The phenomenon of increased loading capacity caused by several contact teeth is called Elastic Meshing Effect (EME). It is of great importance to study EME of three-ring gear transmission to increase loading capacity, minimize design parameters and reduce manufacturing cost. Aimed to make up the deficiency of present product series, the dissertation designs a new product series based on intensity calculation with consideration of EME and the results of elasto-static analysis. The loading capacity of gears is fully developed by changing planetary bears, which are the choke point of loading capacity in primary three-ring gear transmission. Compared with primary product series, the new series has higher loading capacity and more compacted structure through new parameter design. The experiment results of sample reducer prove that the loading capacity of new designed product series is much higher than primary one under the same condition.