Theoretical and experimental investigation on internal gear pair with small sliding ratio

Abstract

Aiming at the issue of sliding ratio, an internal gear pair is proposed which consists of an involute internal gear and a pinion with quadratic curve teeth. Particularly, the contact pattern is point contact and the pinion is generated based on an involute gear. The generation method and mathematical models of the gear pair are presented. The sliding ratio is calculated and the general calculation formulas of sliding ratios are developed. Also, the comparison between the involute gear and proposed gear is made. The adaptability of center distance and contact stress are also discussed. In addition, the gear pair was manufactured and inspected according to the exactitude solid model of the gear pair. In order to confirm this model to be effective, the efficiency experiment and the contrast experiment with the involute gear pair were performed. Furthermore, these two types of pinions were analyzed by scanning electron microscope and wear depths were measured by measuring center. The experiment results show that the efficiency of the internal gear pair is stable at a range about 97.1% to 98.6% and wear depth is less than 50% of the involute gear pair. The internal gear pair is expected to have excellent transmission performance.