Effect of gear tooth imperfection on dynamics of gear transmission systems

Imperfections in gear teeth often result from errors in the manufacturing process or from material wear during operation. Such imperfections in gear teeth can cause excessive vibrations or even an early failure of the transmission system. This paper examines the effects of gear tooth imperfection on the dynamic characteristics of a gear transmission system. The imperfection of a gear tooth was modeled numerically as the deviation of the gear tooth profile from its ideal, or designed geometry. The resulting changes in gear mesh stiffness due to various profile changes because of wear and damage patterns were evaluated acid incorporated into the global dynamic simulation of the gear transmission system. A parametric study was performed to examine the sensitivity of the system vibration due to gear tooth imperfections. The basic parameters used in this study are the magnitude and geometry of tooth profile changes, the number of consecutive gear teeth damaged, and configuration of the gear system. The results of the global dynamic simulations illustrate the feasibility of using changes in gear mesh stiffness in modeling gear tooth imperfections due to damage and wear.