The effect of the installation deviation Gama of the cross angle of the hypoid gear on the fatigue stress of the hypoid gear is similar to the value of the installation offset deviation V, as shown in Fig. 1. It can be seen that the fatigue stress of hypoid gear root is sensitive to the change of Gama. The effect of the same Gama value on the root stress of hypoid gears is just opposite. As shown in Fig. 2, when the gama angle increases in the positive direction, the meshing point of the large wheel of the hypoid gear moves toward the tooth crest near the small end, and moves toward the tooth root near the large end. When the gama angle increases in the negative direction, the meshing point of the large wheel of the hypoid gear moves toward the tooth root near the small end, and moves toward the tooth crest near the large end.
It can be seen from Fig. 1 that the change of equivalent fatigue stress of large wheel of hypoid gear caused by Gama is relatively large. When the gama value increases in a positive direction, the fatigue stress near the small end of the large wheel of the hypoid gear increases sharply, and the fatigue stress near the large end of the small wheel of the hypoid gear decreases. However, the small end contact at the small end of the small wheel of the hypoid gear increases the fatigue stress at the small end of the hypoid gear.
When the gama value increases in the negative direction, the fatigue stress of the hypoid gear small wheel near the big end increases sharply, and the fatigue stress of the hypoid gear large wheel near the small end decreases. However, the large end contact at the big end of the hypoid gear large wheel increases the fatigue stress at the big end of the hypoid gear. The small wheel of hypoid gear is at the small end, and the large wheel of hypoid gear is at the large end. The maximum increase of fatigue stress in the middle of the large wheel of hypoid gear reaches 340mpa, and the maximum increase of fatigue stress at the large end reaches 40MPa. The maximum increase of the middle fatigue stress of the hypoid gear pinion reaches 250Mpa, and the maximum increase of the large end fatigue stress reaches 70MPa. From the above analysis, it can be seen that the change of Gama value will seriously affect the bending stress of the hypoid gear tooth root, and will lead to the edge contact of the hypoid gear.