Novel profile modification methodology for moulded face-gear drives

Abstract

Owing to modern forging and moulding technology, not only are increasing numbers of face gears being made by die, but the quality of the moulded face gear is comparable to that for gears made by a shaping process. The contact pattern of the face gear drive is designed in a manner similar to that for the bevel gear, with a localized bearing that reduces the sensitivity of axes misalignment. This paper proposes a novel profile modification methodology for the moulded face-gear drive that enhances the controllability of the contact pattern and transmission characteristics. Specifically, a skew double crowning is applied on the tooth surface of a face gear whose pinion is a standard involute helical gear. The proposed method - for which computer-aided design software for the tooth surface geometry was developed - can also separately control the bias angle and bearing ratio of the contact pattern, as well as the amplitude of transmission error. Overall, as shown here using several numerical examples, the proposed modified methodology is highly flexible.