The research on Isothermal Elastohydrodynamic Lubrication of cylindrical gears does not consider the influence of time and temperature changes on oil film pressure and oil film thickness. The normal load on the gear teeth remains unchanged, and the cylindrical gears rotate at a uniform speed. The test gear is a pair of involute spur gears, and the standard accuracy grade is grade 7. The basic parameters of cylindrical gear used in numerical calculation are shown in the table.
| Main parameter | Gear pair gear | Gear pair pinion |
| Number of teeth | 24 | 16 |
| Modulus | 4.5 | 4.5 |
| Material Science | 20CrMnTi | 20CrMnTi |
| Young’s modulus | E1 =207GPa | E1 =207GPa |
| Poisson ratio | μ1 =0.254 | μ1 =0.254 |
| Material density | ρ = 7800kg/m3 | ρ = 7800kg/m3 |
| Barus viscosity pressure coefficient | α = 3.3X10-8Pa-1 | α = 3.3X10-8Pa-1 |
| Lubricating oil viscosity | η0 = 0.15Pa/s | η0 = 0.15Pa/s |
| Spindle speed r / min | 2900 | 2900 |
| Tooth width mm | 20 | 20 |
| Contact normal load N | 294 | 294 |
| Indexing circle pressure angle α | 20 | 20 |
| Radial displacement coefficient x1, x2 | -0.5 | 0.85 |
| Outer diameter mm | 112.3 | 88.5 |
| Graduation circle diameter mm | 92.3 | 68.5 |