Study on meshing performance of a novel point-contact hourglass worm drive based on modified involute

•A novel point-contact hourglass worm drive based on modified involute is developed.•The involute modification method and criterion of the standard involute are proposed.•The mathematical model of the novel point-contact hourglass worm drive is derived.•The tooth contact analysis of this novel transmission pair is presented.•The effect of the modification factors on the tooth surface contact stress is studied.