Computerized design, simulation of meshing and stress analysis of pure rolling cylindrical helical gear drives with variable helix angle

Abstract

The geometric design, meshing performance, and mechanical behavior of pure rolling cylindrical helical gear drives with variable helix angle are preseted. This new type of pure rolling gear drives are based on the active design of the meshing line function. Seven types including linear, parabolic, and combined meshing line functions with variable helix angle and parametric equations for convex-to-convex meshing type are discussed. The contact patterns, loaded functions of transmission errors, and the evolution of contact and bending stresses along two pitch angles of rotation of the pinion being evaluated are compared to each other and to a pair of non-standard involute helical gears. Results show that one of the cases of design of pure rolling helical gears with variable helix angle reduces bending and contact stresses compared to the case of pure rolling helical gears with constant helix angle. Compared to involute helical gear drive, contact and bending stresses are increased. However, pure rolling cylindrical helical gears show potential for application as plastic gears in which their complex geometry can be reproduced with injection molding and the phenomenon of pure rolling meshing would contribute to a low heat generation and durability of the gears.