Using five basic equations and MATLAB software for numerical calculation, select six contact points in the direction of gear tooth contact width (evenly distributed along the gear tooth meshing line), and calculate the numerical relationship between the contact oil film thickness and oil film pressure of smooth cylindrical gear, as shown in the figure:
Through numerical calculation, the oil film thickness of 1-6 points in smooth cylindrical gear contact is 11.49 µ m, 15.34 µ m, 12.07 µ m, 18.41 µ m, 15.15 µ m and 16.83 µ m, and the corresponding oil film pressure is 97.301 MPa, 94.835 MPa, 96.417 MPa, 91.676 MPa, 95.270 MPa and 93.049 MPA respectively. It can be seen from the figure that the oil film thickness is extremely thin, and the oil film thickness is inversely proportional to the oil film pressure. The difference of oil film pressure at six points of smooth cylindrical gear is small and average.
| Element | Contact point 1 | Contact point 2 | Contact point 3 | Contact point 4 | Contact point 5 | Contact point 6 | Average thickness Average pressure |
| Oil film thickness µM | 11.49 | 15.34 | 12.07 | 18.41 | 15.15 | 16.83 | 14.88 |
| Oil film pressure Mpa | 97.301 | 94.835 | 96.417 | 91.676 | 95.270 | 93.049 | 94.758 |
The table shows the average oil film pressure (94.758 MPa) corresponding to the average oil film thickness (14.88 µ m).