Viscous friction torque on a concentric journal bearing: T = 4π²·η·N·R³·L / c (R, c in consistent units).
Formula
$$ T = \frac{4 \pi^2 \eta N R^3 L}{c} $$
Symbol legend
| Symbol | Meaning | Unit | Source |
|---|---|---|---|
| $η$ | Dynamic viscosity | Pa·s | oil at T |
| $N$ | Rotation rate | rpm | tachometer |
| $R, L, c$ | Journal radius, length, clearance | mm | bearing spec |
Sources
- Petroff (1883).