In order to study the influence of different speed and load conditions on the gear stress in the meshing transmission process of spiral bevel gear under dynamic loading, the variation laws of tooth surface contact stress and tooth root bending stress of spiral bevel gear under different working conditions were obtained. According to the contact force and contact area, the contact stress of the tooth surface after impact is calculated; The bending stress of tooth root can be extracted from the results of finite element contact analysis. Maximum tooth surface contact stress and maximum tooth root bending stress under various working conditions.
It can be seen that under the dynamic loading condition, the maximum contact stress and bending stress of spiral bevel gear increase with the increase of torque, which is consistent with the static analysis conclusion in the previous chapter. However, the influence of speed on the maximum contact stress and maximum bending stress of spiral bevel gear does not show obvious regularity. In order to analyze the variation characteristics of tooth surface contact stress under different working conditions in detail, the nephogram of tooth surface contact stress during dynamic loading of spiral bevel gear is intercepted respectively, as shown in Figure 1 ~ 5.
Fig. 1, Fig. 2 and Fig. 3 show that the influence law of rotating speed on tooth surface contact stress is not obvious; In the process of meshing transmission, the maximum contact stress of spiral bevel gear occurs near the midpoint of tooth width; The shape of the contact area is approximately elliptical and has a certain inclination in the direction of tooth width; After loading, the tooth surface contact area of spiral bevel gear will move slightly from the small end to the middle, and the tooth surface contact area under various working conditions is irregular oval; Figure 1, figure 4 and figure 5 show that with the gradual increase of load, the contact area increases in varying degrees in terms of length and width; The position of the maximum contact stress is distributed in the center of the contact area.
In order to analyze the influence of the speed and torque of the spiral bevel gear on the position of the maximum bending stress of the spiral bevel gear, the nephogram of the bending stress of the gear tooth root during the dynamic loading of the spiral bevel gear is extracted respectively, as shown in Fig. 6 ~ 10.
The dynamic bending stress nephogram in Figure 1, figure 2 and figure 3 shows that when the spiral bevel gear is engaged under high-speed and heavy load conditions, the stress in the tooth contact area increases with the increase of load; It can be seen from Fig. 1, FIG. 4 and Fig. 5 that the influence of rotating speed on the bending stress of tooth root is relatively vague; The maximum value of dynamic tooth root bending stress of spiral bevel gear increases with the increase of load; The position of the maximum root bending stress under different working conditions appears directly below the position of the maximum contact stress.