The image above represents r.p.m of driver pulley.

To compute for r.p.m of driver pulley, three essential parameters are needed and these parameters are **Diameter of Driven Pulley (D _{b}), r.p.m. of Driven Pulley (r_{b})** and

**Diameter of Driver Pulley (D**

_{b}).The formula for calculating r.p.m of driver pulley:

r_{a} = ^{(Db x rb}/_{Da}

Where:

r_{a} = r.p.m. of Driver Pulley

D_{b} = Diameter of Driven Pulley

r_{b} = r.p.m. of Driven Pulley

D_{a} = Diameter of Driver Pulley

Let’s solve an example;

Find the r.p.m of driver pulley when the diameter of driven pulley is 21, the r.p.m of driven pulley is 18 and the diameter of driver pulley is 14.

This implies that;

D_{b} = Diameter of Driven Pulley = 21

r_{b} = r.p.m. of Driven Pulley = 18

D_{a} = Diameter of Driver Pulley = 14

r_{a} = ^{(Db x rb}/_{Da}

r_{a} = ^{(21 x 18)}/_{14}

r_{a} = ^{378}/_{14}

r_{a} = 27

Therefore, the **r.p.m of driver pulley **is **27 Hz.**

Continue reading How to Calculate and Solve for r.p.m of Driver Pulley | Pulley Size Calculations