Study On Bending Strength Design Method And Efficiency Problem For Involute Internal Gear Pairs With Small Tooth Number Difference

Involute planetary gear drive has the following significant features including large gear ratio, small capacity, and high strength. It has been widely applied. This paper conducts research on the computing of the stub gear bending strength and multi-gear meshing bending strength. It provides new method and data for design of planetary gear drive with small tooth number differenceStub gear is usually adopted in planetary gear drive with small tooth number difference. However, relevant national and international standards do not provide gear shape coefficient and stress modification coefficient. It is unable to conduct bending fatigue strength computing. The paper adopts finite element to conduct systematic research on the teeth root stress of the stub gear, establishes compound teeth shape coefficient and solves the critical problem with short-teeth bending fatigue strength computing.Planetary gear drive with small tooth number difference adopts few internal teeth meshing gears. The theoretical meshing teeth have small clearance with the adjacent teeth gear on both sides. The elastic deformations generated while the teeth bears load will eliminate the clearance, compelling the multiple teeth pairs to mesh, thus enhancing the bearing capability. This paper adopts finite element to conduct systematic research on the teeth root stress of the stub gear, determines the number of touching teeth gear from one tooth to five teeth and in case of different number of teeth, analyzes the major affecting elements and the reason. It also established multi-teeth meshing and bending strength coefficient on basis of teeth root stretching stress computing, solving computing problems of multi-teeth meshing and bending fatigue strength.Completing the prototype design and manufacture of reducer, and studied the problem of efficiency.The findings of this paper provide new approach to design of planetary gear drive with small tooth number difference. In-depth research could be conducted on its strength computing on basis of this paper.