V Belt Calculator
We will introduce you to the right V belt length formula, which will help you determine the perfect V belt size with a v belt calculator.
But before we proceed, the important things that a V belt calculator determines are all the parameters of a belt drive system:
- The RPM
- The speed
- Belt length
- Belt tension
- Torque
Belt Length
To calculate the length of a V belt in a two-pulley system with pulleys of different diameters, you need to input the distance between the axles of the pulleys and their diameters into the formula mentioned below;
Belt length = ((DL + DS) * π / 2) + (DL - DS) * arcsin((DL - DS) / 2L) + 2 * √(L2− 0.25 * (DL - DS)2
Here;
- DL = diameter of the large pulley;
- DS = diameter of the smaller pulley; and
- L = distance between the pulley axles.
For example,
If you own a factory and you need to calculate the v-belt length. The diameter of each pulleys is 15 and 30 cm, and you would want the distance between them to be 1.5 meters. Then,
- DL = 30 cm = 0.3 m
- DS = 15 cm = 0.15 m
- L = 1.5 m
By putting values into the equation
Belt Length = ((0.3 + 0.15) * π / 2) + (0.3 - 0.15) * arcsin((0.3 - 0.15) / 2*1.5) + 2 * √(1.52− 0.25 * (0.3 - 0.15)2) = 3.71 m
It's pretty simple.
There is another relatively easy formula to determine length as well. It is also common among engineers and is an approximation of the one given above:
Belt length = ((DL + DS) * π / 2) + (2 * L) + (DL - DS)2 / (4 * L)
Here:
- DL = diameter of the large pulley;
- DS = diameter of the smaller pulley; and
- L i= distance between the pulley axles.
This formula works well for two pulleys of a similar size or ones that are further apart. The estimation of this formula can fail if one pulley is much larger than the other and they are close together. However, such cases happen rarely in engineering.