The formula to calculate the Velocity Ratio of Compound Belt Drive is:
\[ i = \frac{N_n}{N_{d1}} \]
Velocity ratio is the distance through which any part of a machine moves to that which the driving part moves during the same time. Speed of the last driven pulley is the number of turns of the object divided by time, specified as revolutions per minute (rpm), cycles per second (cps), radians per second (rad/s), etc. Speed of the first driver is the number of turns of the object divided by time, specified as revolutions per minute (rpm), cycles per second (cps), radians per second (rad/s), etc.
Let's assume the following values:
Using the formula:
\[ i = \frac{0.366666666666667}{0.466666666666667} = 0.785714285714286 \]
| Speed of Last Driven Pulley (Nn) | Speed of First Driver (Nd1) | Velocity Ratio (i) |
|---|---|---|
| 0.3 | 0.466666666666667 | 0.642857142857142 |
| 0.35 | 0.466666666666667 | 0.750000000000000 |
| 0.4 | 0.466666666666667 | 0.857142857142856 |
| 0.45 | 0.466666666666667 | 0.964285714285714 |
| 0.5 | 0.466666666666667 | 1.071428571428571 |