According to the theory and three-dimensional modeling process of hypoid gears with small number of teeth and large reduction ratio, a pair of 3:60 hypoid gears are designed by increasing the transmission ratio to 20 using the same method mentioned above. Considering the undercutting of the small wheel and the sharpening of the tooth top, the spiral angle of the aligned hyperboloid gear takes a larger value, and the spiral angle at the midpoint of the small wheel reaches 72 °. And carry out height displacement and tangential displacement. The tooth top height coefficient is 0.05 and the tooth height coefficient is 3.4.
A series of tooth surface points are obtained by MATLAB program and imported into UG to establish the large and small wheel model of hypoid gear, as shown in Fig.1 and 2.
It can be seen from the figure that the hypoid gear pinion and wheel is intact. Except that the longitudinal tooth shape is more curved, the tooth root is continuous without undercutting; The thickness distribution of tooth tip is appropriate without sharpening. Therefore, the scheme of 3-tooth small wheel transmission for Hypoid gear is feasible.