New Approach to Computerized Design of Spur and Helical Gears

Abstract

The approach to the design of spur and helical cylindrical gears is being considered on the basis of application of special type geometrical objects named dynamic blocking contours (DBC) by means of which the rational choice of addendum modification coefficients (profile shift coefficients) of pinion and gearwheel is carried out. The stage of shift coefficients selection by means of DBC is singled into an independent procedure during which some gear qualities may be forecast before basic geometrical and strength calculations, that is, at the initial stage of design. Based on the concept of DBC, the computer-aided design of spur and helical gears has been developed with the practical realization of the stated design principles. In order to provide better obviousness of the design, CAD includes visualization units of meshing process of gear pair and meshing element generation by rack type cutting tool. Educational release of the developed system allows the user to master the methodology and possibilities of gear design on the basis of DBC concept and to evaluate the importance of shift coefficients selection to obtain specified properties of gears.