Meshing analysis of mismatch toroidal worm gearing characterized by different basic parameters of hob and worm

Aiming at high error sensitivity and complicated worm gear manufacturing of the planar double enveloping toroidal worm drive, a new TP-H gearing which worm generates by a plane and the worm wheel generates by a straight profile hob is proposed. Firstly, a comprehensive and systematic meshing theory of this drive is established; A rigorous calculation method for the instantaneous contact point is proposed; A formula for calculating the eccentricity of the instantaneous contact ellipse based on the relative principal curvature is deduced, and it is suggested innovatively that the eccentricity can be used as the quantitative index for describing the degree of mismatch between teeth. Secondly, the selection and matching strategy of mismatched process parameters is given, and the contact behavior between tooth surfaces is simulated based on numerical examples, the results show that the novel transmission can achieve good point contact. The research will promote the in-depth development of the theory of mismatched meshing in toroidal worm drive, and explore the specific form of gearing with simple manufacturing, low error sensitivity, and considerable meshing performance.