The heating flow density is applied to the meshing contact helical gear tooth surface, and the convective heat transfer coefficient is applied to the tooth top surface, tooth root surface and helical gear end face respectively. The convective heat transfer coefficient of the tooth top surface and tooth root surface can be equivalent to 1 / 3 of the convective heat transfer coefficient of the gear meshing surface. The loading boundary conditions of the temperature field are shown in Figure 1.
In order to reduce the amount of calculation, the six teeth meshing of large and small gears are intercepted, and the four helical gear teeth of the driving wheel are studied and analyzed; The 6-sided c38r is selected as the grid element for grid division, and the contact surface and root position of the gear teeth are grid densified. Angular velocity is now applied to the driven wheel ω ＝ ０. 55r / s, applied torque of driving wheel t = 1500N · m, as shown in Figure 1.
It can be seen from Figure 2 that the contact tooth surface in helical gear transmission always presents the state of alternating meshing of two teeth, three teeth and two teeth, in which figure 2 (a) shows two teeth meshing; Fig. 2 (b) shows that three teeth begin to enter the meshing, and the two teeth meshing changes into three teeth meshing; Fig. 2 (c) shows that one tooth ends meshing and three tooth meshing is converted to two teeth; Figure 2 (d) shows that 4 teeth begin to enter the meshing, and the two tooth meshing is transformed into three tooth meshing.
In the meshing transmission process of helical gear, the contact load on the tooth surface of helical gear always moves and distributes along the helix direction, and the contact load on the tooth surface of helical gear gradually moves from the tooth root to the tooth top. Because the two teeth and three teeth mesh alternately in the meshing process, the length of the contact line also changes, so that the contact load on the helical gear teeth changes accordingly with the meshing position of the helical gear. The total contact force calculated by simulation is about 42111 7n, while the theoretical value is about 42597 5N, the error value of simulation and theoretical calculation is 1 14%, which verifies the correctness of the simulation contact model.