1. What is Pulley Reduction?

Pulley reduction refers to the ratio between the diameters of the driver (input) pulley and the driven (output) pulley. This ratio determines the speed and torque relationship between the two pulleys in a belt drive system.

2. How Does the Calculator Work?

The calculator uses the pulley reduction formula:

Where:

• \( Driver\ Diameter \) — Diameter of the driving pulley (inches)
• \( Driven\ Diameter \) — Diameter of the driven pulley (inches)

Explanation: A ratio greater than 1 indicates speed reduction (output slower than input), while a ratio less than 1 indicates speed increase.

3. Importance of Pulley Ratio

Details: The pulley ratio is crucial for determining the speed and torque relationship in mechanical systems. It affects the performance of engines, machines, and various mechanical drives.

4. Using the Calculator

Tips: Enter both pulley diameters in inches. The driver pulley is the one connected to the power source, while the driven pulley is the one being turned by the belt.

5. Frequently Asked Questions (FAQ)

Q1: What's the difference between reduction and increase ratios?
A: A reduction ratio (>1:1) decreases speed but increases torque, while an increase ratio (<1:1) increases speed but decreases torque.

Q2: How does pulley ratio affect RPM?
A: Output RPM = Input RPM × (Driver Diameter/Driven Diameter). A 2:1 ratio halves the RPM but doubles the torque.

Q3: Can I use this for multi-pulley systems?
A: For multiple pulleys, calculate each stage separately and multiply the ratios for the total system ratio.

Q4: What about belt length calculations?
A: This calculator only determines ratio. Belt length depends on pulley diameters and center distance between shafts.

Q5: Does pulley width affect the ratio?
A: No, the ratio depends only on the effective diameters, though wider pulleys can handle more power.