Meshing performance analysis on modified roller enveloping toroidal worm gearing

A new transmission style of worm gearing, named modified roller enveloping toroidal worm gearing, with multi-worm gear teeth meshing is proposed in order to enhance the loading capacity, transmission accuracy and efficiency of worm gearing. According to the principle of gear engagement, the dynamic coordinate axis method was used to establish the fixed and moving coordinate axes of this new transmission style and the moving coordinate axis at the conjugate point. The calculation formulas of meshing performance parameters such as induced principal curvature, lubrication angle and relative entrainment velocity were derived. Finally, the influence of design parameters such as throat coefficient, transmission ratio and roller root radius on the meshing performance of this transmission style were analyzed. The results showed the maximum lubrication angle of this transmission style is more than 88º, which has good lubrication performance. Larger throat coefficient, larger transmission ratio and suitable roller root radius can obtain excellent meshing performance under the conditions of satisfying the strength and stiffness of the toroidal worm's throat diameters. The research in this paper provides a theoretical basis for the optimization, design and processing of this new transmission style.