The formula to calculate the Maximum Efficiency of Screw Jack is:
\[ \eta = \frac{1 - \sin(\Phi)}{1 + \sin(\Phi)} \]
The Efficiency of an electric motor is defined as the ratio of usable shaft power to electric input power.
Let's assume the following values:
Using the formula:
\[ \eta = \frac{1 - \sin(0.21816615649925)}{1 + \sin(0.21816615649925)} = 0.644142444132729 \]
| Limiting Angle of Friction (Φ) | Maximum Efficiency (η) |
|---|---|
| 0.2 rad | 0.668516870014 |
| 0.21 rad | 0.654999061413 |
| 0.22 rad | 0.641726618781 |
| 0.23 rad | 0.628694305611 |
| 0.24 rad | 0.615897031562 |
| 0.25 rad | 0.603329847690 |
| 0.26 rad | 0.590987941854 |
| 0.27 rad | 0.578866634295 |
| 0.28 rad | 0.566961373384 |
| 0.29 rad | 0.555267731534 |