See rotation through gears and pulleys
Switch between external gears and an open belt to inspect speed ratios and rotation direction.
Diagram and inputs ↓Choose another visualization (19 topics)
Start with a reference or example
Get a sense of the value, then inspect the diagram or motion.
| Reference / example | Value | What it means | Use |
|---|---|---|---|
| Gear reduction | 20 → 40 | 30 rpm input → 15 rpm output; opposite direction | |
| Gear speed increase | 40 → 20 | 30 rpm input → 60 rpm output; opposite direction | |
| Pulley example | 20 → 40 mm | 30 rpm input → 15 rpm output; same direction |
Assumes matching gear modules or no belt slip. Pulley dimensions are effective/pitch diameters.
Applies to condition A. Then press Play or Reveal.
Conditions
Enter integer tooth counts for gears or belt pitch/effective diameters for pulleys.
Visual preview
Ready2D · front view of gears / pulleys
Tooth outlines are approximate illustrations. Assumes a no-slip belt and backlash-free external gears. This is not a tooth, strength or belt-tension design tool.
How to read this view
Ratio and direction
Output rpm=input rpm×driver teeth/driven teeth. External gears rotate oppositely; an open belt rotates in the same direction. For pulleys, use effective diameters instead of teeth.
High-speed display
Choose slow playback when the fastest displayed wheel exceeds 120 rpm. Follow the highlighted marker rather than apparent tooth flicker.
Sources and references
- KHK — 歯車列の速度比と回転方向