Worm-Type Gear with Steel Gearwheel

Abstract

The manuscript presents a study of a variety of a worm gear having a truncated gear rim as compared to the common worm gear. This gear has been originally invented by Egorov and Iofik and, as shown here, it has a number of favorable geometrical and kinematic, power, strength, layout, and manufacturing properties. It is offered to name it “QN-gear” and to use hardened steel as the material of its gear rim that sharply raises its strength. The quantitative and qualitative comparison with the nearest analogues—worm and spiroid gears has shown the perspective of applying such a gear design, first of all, for the case of low rotation speeds. Equations are obtained for calculation of the worm axial module and dependences for prevention of tooth undercutting and sharpening, which are, in fact, limitations at optimization design. Proposals are made to improve the performance and production characteristics of QN-gears with hardened steel gearwheel rims by gear optimization and contact localization. To improve the economic efficiency of gear production, it is proposed to produce gearwheels with curvilinear and asymmetric profiles by means of standard involute hobs and multi-cutter running heads. An example of a gearbox based on the steel QN-gear is given showing high load characteristics in testing.