Taking the driven cone as the research object, the elastic modulus of spiral bevel gear under the design point condition (20 132r/min, 1000 kW, 140 ℃) is 1 0Eo( Eo = 2. 08 GPa) means that 0 9Eo、0. 95Eo、1. 0Eo、1. 05Eo、1. 1Eo studies the influence of the elastic modulus of spiral bevel gear material on the lubrication characteristics of the meshing area. 0 9Eo、1. 0Eo、1. In the case of 1Eo, the two-dimensional contour curves of oil film pressure, oil film thickness and oil film temperature rise are shown in the figure. The changes of maximum oil film pressure, minimum oil film thickness and maximum oil film temperature rise with elastic modulus are shown in Table 1. It can be found that with the increase of the elastic modulus, the maximum oil film pressure and the maximum oil film temperature rise both increase, while the minimum oil film thickness decreases. This is because the increase of the elastic modulus reduces the elastic deformation of spiral bevel gears, thus increasing the pressure of the oil film, leading to the increase of the temperature rise and the decrease of the film thickness.
According to Table 1 and the formula, the corresponding sensitivity coefficient of each oil film characteristic parameter when the elastic modulus changes is shown in Table 2. It can be seen that the sensitivity coefficient of maximum pressure and maximum temperature rise at the design point is greater than 1 and the data is relatively stable, so the elastic modulus can be used as the key parameter to adjust the maximum pressure and maximum temperature rise. The sensitivity coefficient of the minimum film thickness is small and the data fluctuation is small. The minimum oil film thickness can be fine-tuned by adjusting the elastic modulus.
| E/GPa | hmin / μm | pmax /GPa | Δtmax /℃ |
| 1.872 | 0.539 | 0.321 | 9.452 |
| 1.976 | 0.531 | 0.345 | 10.115 |
| 2.080 | 0.524 | 0.369 | 10.823 |
| 2.184 | 0.518 | 0.395 | 11.581 |
| 2.288 | 0.513 | 0.421 | 12.397 |
After obtaining the sensitivity coefficient of each oil film characteristic parameter of spiral bevel gear to the input parameter, the average value of the sensitivity coefficient under different working conditions is taken to rank, so as to obtain the influence degree of each working condition parameter on the oil film characteristic parameter.
| Pk | 90%Eo | 95%Eo | 100%Eo | 105%Eo | 110%Eo |
| hmin | 0.286 | 0.267 | — | 0.229 | 0.210 |
| pmax | 1.301 | 1.301 | — | 1.409 | 1.409 |
| Δtmax | 1.267 | 1.308 | — | 1.401 | 1.454 |
It can be seen that different operating parameters have different degrees of influence on the oil film characteristic parameters of spiral bevel gears. Therefore, when there is dry friction, good lubrication can be obtained by adjusting the corresponding operating parameters. The viscosity of lubricating oil, rotating speed and elastic modulus of material have a greater impact on the various characteristic parameters of the oil film, while the impact of power is generally small. The temperature rise of lubricating oil will change by more than 10% when the elastic modulus, viscosity and rotational speed of the material change by 10%. Every 10% change in viscosity and rotational speed will result in no less than 5% change in oil film thickness. To sum up, the degree of influence on the maximum pressure of oil film of spiral bevel gears is from large to small in terms of elastic modulus, viscosity, rotational speed and power; The degree of influence on the maximum temperature rise and minimum oil film thickness of the oil film is from viscosity, rotational speed, elastic modulus and power.