C-Gears: Geometry and Machining

Abstract

Cylindrical gears with lengthwise curved teeth, or C-gears for short, have repeatedly been suggested during the past 90 years, without having found widespread application. However, it seems that they are presently on the verge of being reconsidered for applications where their characteristic tolerance of misalignment is indispensable, particularly when this merit outweighs all other issues of concern. In this paper, the geometrical features of 11 different forms in which C-gears could come are detailed in connection with their cutting and finish-grinding methods. The limitations and demerits are discussed and some problem areas that need further investigation are highlighted. The information given herein should be valuable to mechanical engineers whenever they would envisage using C-gears or designing generators for them. In spite of the sometimes lengthy description of the geometry, a scent of the history of C-gears and their machining methods is perceived throughout the paper.