Innovations in Design of Worm-type Gears in the Last Two Decades

The manuscript presents a review of innovationsInnovation in the design of worm-type gears which are made at the Research and Production Center “Institute of Mechanics named after Prof. Veniamin I. Goldfarb”, Izhevsk, Russia. The main innovationsInnovation considered are spiroid gearsSpiroid gears with special cases of low speeds and small gear ratios, worm cylindrical gears with steel hardened gearwheels, and planetary spiroid gearsSpiroid gears. The features of low-speed spiroid and worm gearsWorm gears in multi-nomenclature series production are extremely heavy loads, the need to take into account layout limitations, unification and simplification of gear cutting tools, implementation of several gear ratios in one design. For small gear ratios, the spiroid gearSpiroid gears can be an effective alternative to hypoid and bevel gears due to its favorable meshing characteristics and economical and affordable production technique. The use of hardened steel for worm gearwheels is related with a favorable arrangement of the conjugate contact lines for lubrication and scuffing resistance—at large angles with respect to the vector of relative velocity. Two versions of such worm gearsWorm gears are considered. The use of worm and spiroid gearsSpiroid gears in a planetary mechanism provides an extremely high gear ratio, compact design and smooth operation.