Study on meshing characteristics of helipoid gears with surface modification

The modification of tooth surface of pinion was applied to improve the meshing characteristics of helicoid gears. The modified shaper tooth surface could be generated by an imaginary rack cutter with the parabola profile, and the derivation of the mathematical of helicoid gears was developed by simulating the meshing kinematics between the shaper and the generated gear. By considering the assemble errors, the tooth contact analysis model was established on the conditions of continuous tangency of two contact surfaces. The results of computerized simulation of meshing and contact show that, the convex type transmission error can be produced by the modification of rack cutter profile, the amplitude and symmetry of transmission error can be changed by modulating the modification parameters; and the crossing angle has a great effect on the contact ratio, the contact ellipses and the sensitivity of assembly errors of the helicoid gears.