Abstract
Due to the low error sensitivity, the local conjugate enveloping hourglass worm drive based on medium gear is being intensively investigated, and this article examines the local conjugate meshing performance of such a worm drive. In this article, the local conjugate principle grounded in modified involute is proposed, and the local conjugate meshing hourglass worm drive using this approach is established; the boundary conditions of the modified involute are set up, and the oblique planar gear is converted to modified involute gear form; the meshing contact area of the worm drive is analyzed using tooth contact analysis (TCA), and finite element analysis (FEA) is executed to validate TCA's accuracy and perform loaded tooth contact analysis (LTCA); the mathematical models of the micro meshing properties are derived, and the effects of the modification position and range on meshing performance are examined. The findings indicate that the modification parameters influence the transmission pair's meshing performance, which subsequently affects the transmission performance. Thus, by reasonably selecting the modification position and range, a local conjugate hourglass worm drive with better meshing performance can be obtained.