Clockwork Gear Train Simulator (2D)

Driving Gear

Driving speed 30 RPM

Driver teeth 24

Driven Gear

Driven teeth 12

Input Torque

Driver torque 10.0 N·m

Gears meshing — steady state.

Live Readout

Gear ratio (driver:driven)

2.00 : 1

Driven speed

60 RPM

Driven torque

5.0 N·m

Driven direction

Same

How it works

Two meshing gears turn at speeds inversely proportional to their tooth counts: ω_driven = ω_driver × (T_driver / T_driven). A small gear driven by a large one spins faster; a large gear driven by a small one spins slower — exactly the mechanism a clockwork train uses to step a fast mainspring down to a slow, steady hand.

Torque works the opposite way. Ignoring friction, power is conserved across the mesh (P = τω is the same on both shafts), so torque scales with the inverse of the speed ratio: τ_driven = τ_driver × (T_driven / T_driver). Gearing down for speed always gears up for torque, and vice versa — you never get both for free.

Two directly meshing gears always spin in opposite directions. Adding a third gear — an idler — between them reverses the sense again, so the driven gear ends up turning the same way as the driver. An idler changes only the direction of the output, never the overall speed or torque ratio, since its own tooth count cancels out of the chain.

Driver gear Idler gear Driven gear