How does pulley size affect RPM?
By changing the diameter of the pulley wheels, speed can be changed. A smaller pulley turning a larger pulley results in the larger one moving more slowly but with more shaft power.
What is the pulley ratio?
Calculate the pulley ratio by dividing the pulley’s pitch diameter by the pitch diameter of the drive pulley. For example, suppose the drive-shaft has a diameter of 2.2 inches, and two pulleys driven by the belt have diameters of 4.4 inches and 2.8 inches. The first ratio is: 4.4 2.2 = 2 \frac{4.4}{2.2}=2 2.
How do pulleys reduce rpm?
Add half of the diameter of each pulley to twice the shaft-center-to-shaft-center distance. Get the next larger standard size of belt. Install the belt on the pulleys and move the units apart until the belt has a slack of about 1/2 inch.
Does a smaller pulley increase speed?
Pulleys of Different or Same Size If a smaller pulley turns a larger one, the larger one will turn slower, but with more power available at the shaft. If a bigger pulley turns a smaller one, the smaller one will turn much faster than the bigger one but with less power available at the shaft.
How does a pulley ratio work?
Example
- Velocity ratio = diameter of the driven pulley ÷ diameter of the driver pulley.
- The smaller driver pulley turns ten times for every one turn of the driven pulley.
- Output speed = input speed ÷ velocity ratio.
- The smaller driven pulley will turn at 3,000 rpm.
How do you calculate the RPM of a pulley?
Calculate the Speeds. Calculate the speed of each pulley by dividing the drive speed by the pulley ratio. For example, given a drive speed of 750 RPM, the speed of the first pulley = 750/2 = 375 RPM, and the speed of the second pulley = 750/1.27 = 591 RPM.
How to calculate pulley ratios?
Calculate the pulley ratio by dividing the pulley’s pitch diameter by the pitch diameter of the drive pulley. For example, suppose the drive-shaft has a diameter of 2.2 inches, and two pulleys driven by the belt have diameters of 4.4 inches and 2.8 inches.
What is the ratio of a pulley?
The pulley ratio is the diameter of the crankshaft pulley divided by the diameter of the alternator pulley. Multiply that number times the engine RPM to get the alternator RPM. For example, a 6 inch crankshaft pulley and a 2 inch alternator pulley equals a pulley ratio of 3:1. Three times an engine speed of 800 RPM equals 2,400 alternator RPM.
What is the formula for pulley?
The formula for sizing a pulley is: Engine Speed (RPM) =. Pulley Diameter (Generator) Generator Speed 3600 RPM. Pulley Diameter (Engine)