A New Type Double-Enveloping Worm Gears : 1st Report, Fundamental Analysis on the Tooth Engagement Action

Abstract

The author designed a new type double-enveloping worm gears. In this new type the worm is a conventional hourglass worm, but the number of teeth of the worm wheel and the center distance are smaller than the conventional type. In this paper the design principle is presented. With Hindley type worms, surfaces of action or lines of contact of the new worm gears are theoretically obtained and compared with those of the following two types of worm gears : (1) the cylindrical worm gears having a worm thread of a straightsided axial section. (2) the Hindley worm gears. The following conclusion is obtained. It may be considered that the new worm gears is a general form of the above mentioned two types of the conventional worm gears, and can be properly designed to circumvent the defects of the latter two types without sacrificing the desirable features as a worm gears.