Hourglass Worm Gears Designed to Concentrate Surface Normals : Manufacturing and Experimental Investigation on Tooth Bearing

Abstract

To avoid the influence from the small displacement of gear axes under load, the authors propose that all contact normals of a tooth surface be at right angles to the direction of the small displacement induced at each contact point under load. On the basis of this state of surface normals, a few methods for tooth surface generation have been devised for realizing this concept. In this research, an hourglass worm gear having the above geometrical characteristics was made using the conventional methods of tooth surface generation and tooth bearing of the worm gear was experimentally tested. As a result, the validity of this design concept was proven.