Abstract
This research proposes the method of manufacturing wheels which changed the number of teeth by the same hob. The designed hourglass worm gear requires the center distance corresponding to number of teeth. A design-criteria point is located in the throat of the standard hourglass worm. And center distance is defined when a wheel and a worm fulfill the conditions of contact. The geometric performance of the designed hourglass worm gears is investigated. Compared with cylindrical worm gears, it is high performance and the validity of the proposed method became clear.