1. What is Pulley Ratio?

The pulley ratio is the relationship between the diameters of two pulleys in a belt drive system. It determines the speed ratio between the driving and driven pulleys and affects torque transmission.

2. How Does the Calculator Work?

The calculator uses the pulley ratio formula:

Where:

• \( D1 \) — Diameter of the driver pulley
• \( D2 \) — Diameter of the driven pulley

Explanation: The ratio shows how many times the driven pulley will rotate for each rotation of the driver pulley. A ratio greater than 1 indicates speed increase, while less than 1 indicates speed reduction.

3. Importance of Pulley Ratio

Details: Proper pulley ratio selection is crucial for achieving desired speed and torque in mechanical systems. It affects efficiency, belt life, and overall system performance.

4. Using the Calculator

Tips: Enter diameters of both pulleys in the same units (typically mm or inches). Both values must be positive numbers.

5. Frequently Asked Questions (FAQ)

Q1: How does pulley ratio affect speed?
A: The driven pulley's speed equals the driver pulley's speed multiplied by the ratio. Higher ratio means faster driven pulley speed.

Q2: What's the relationship between ratio and torque?
A: Torque changes inversely with speed. A speed-increasing ratio (D1 > D2) reduces torque, while a speed-reducing ratio (D1 < D2) increases torque.

Q3: Can I use this for belt length calculation?
A: No, this only calculates ratio. Belt length depends on pulley diameters and center distance.

Q4: What's a typical pulley ratio range?
A: Common ratios range from 1:3 to 3:1, but extreme ratios may require special belt designs.

Q5: Does belt thickness affect the ratio?
A: For precise calculations, use the pitch diameter (accounting for belt thickness) rather than outer diameter.