Parametric design approach on high-order and multi-segment modified elliptical helical gears based on virtual gear shaping

Abstract

In the past, family of elliptic gears with closed pitch curve includes elliptic gears, high-order elliptic gears, modified elliptic gears, and high-order and two-segment modified elliptic gears. On this basis, this article expands their connotation and unifies them into high-order and multi-segment modified elliptical helical gear (HOMSMEHG), and puts forward the expression of pitch curve. In order to obtain a physical model with real tooth flanks, this article proposed a parametric design approach on the HOMSMEHG based on virtual gear shaping, including decoupling basic parameters, parametric design based on the shaping cutter, and design of shaping linkage models, which had laid a theoretical foundation for designing the HOMSMEHG. Moreover, the realization technology of parametric design was also offered, which had solved the key problem of engineering implementation. Finally, two cases of designing internal and external gears are provided based on virtual gear shaping, which shows that the design approach of the HOMSMEHG and the virtual shaping method proposed in this article are feasible. The tooth flanks of the gears obtained has obvious cutting marks, and conforms to the real ones, which can ensure the reliability of the dynamic or kinematic analysis.