Effects of Rim Thickness and Number of Teet on Bending Strength of Internal Gear

An internal gear which meshed with three planet gears in the same bearing condition, the angles between those planet gears being same and 120° respectively, and which was supported through a thin cylinder, was chosen as the subject of study. The bending moment, the bending stress and the radial displacement in the rim of the internal gear were obtained theoretically, and by using these results the form of an internal gear model was determined. Furthermore, the stresses in the internal gear models were analyzed by the photoelastic method, and the effects of rim thickness and number of teeth of the internal gear on the magnitude and the position of the maximum stress produced in the internal gear were clarified.