Dynamic characteristics of torus involute gear drive

The torus involute gear drive originates from the involute spur gear drive, which is composed of a gear with convex teeth and the one with concave teeth. Previous researches of its mesh principle indicate that the torus involute gear can compensate large axial misalignments in parallel-shaft transmission, while its dynamic behavior has not been investigated comprehensively, or compared with that of the standard involute gear. This paper focuses on the dynamic performance of this type of gear. Considering the time variation of meshing stiffness, a 6-degree-of-freedom dynamics model of the torus involute gear pair is established, which counts in the effect of alternate meshing of single-double tooth pairs. Sliding friction in elastohydrodynamic lubrication is also included in the model. The numerical analysis for six cases is conducted, and the dynamic characteristics such as the dynamic transmission error, mechanical efficiency, sliding friction forces and minimum oil-film thickness are compared with those of the standard involute gear. The results show that, the torus involute gear drive exhibits good performances as the standard involute gear drive in transmission accuracy and mechanical efficiency, while, it has a better performance in lubrication condition. The study in this paper may lay theoretical foundations for practical application of the torus involute gears.