Novel tooth modification methodology for multistage spur gears considering dynamic deformation of housing

Abstract

Tooth modification is critical when designing high-performance gear transmission systems. However, it is difficult to accurately calculate the system deformation and tooth modification amount using the traditional empirical formula. Although the finite element method provides accurate results, it is time consuming and its direct application to tooth modification for multistage geared systems is difficult. This study proposes a novel methodology to define tooth modification in both width and profile directions, which can be used for multistage spur gears. First, a housing-transmission coupled dynamic model is built, and the actual meshing state of each gear pair is obtained from dynamic simulation. Lead and profile modification are then conducted sequentially using the actual meshing state as an input. As the optimal tooth modification parameter is determined by the system dynamic response, and the tooth modification in turn influences the system dynamic response, the “dynamic simulation” and “tooth modification” are repeated iteratively until the modification parameter converges. Taking the drum driving system of a shearer as an example, the optimal tooth modification parameter is obtained after three iterations, and the dynamic factor and maximum tooth contact stress clearly decreased after applying the optimal tooth modification.