Active design method and performance prediction of internal gear pairs with low sliding ratio

Reducing relative sliding between tooth surfaces contributes to the improved reliability of gear operation. This paper presents an active design of an internal gear drive with low sliding ratio (LSR). In order to achieve a lower sliding ratio, the relationship between the sliding ratio and the contact path is established. The tooth profiles of the internal gear are determined based on a given contact path using a cubic function. Tooth interference issues arising during gear meshing and machining are systematically analyzed. Additionally, tooth profile features are illustrated through an example. The operating performance, including tooth strength and lubrication characteristics, is evaluated through a comparison with that of the traditional involute gear drive. Results indicate that the novel internal gear transmission exhibits excellent resistance to wear, bending, and lubrication performance. Finally, the rationality of the tooth profile design is validated through physical assembly.