A sprocket-wheel to drive or to be driven by a chain

Only the input is driven; every other part of this model moves by physics (MuJoCo), and its ratios are measured. Run it live, change its parameters, or switch the friction off to see the output stop.

Modelled as

Face view, axes level, gravity on. Two equal sprocket-wheels of 14 teeth (pitch 2 cm, pitch radius 4.494 cm) stand 16 cm apart. An endless roller chain of 30 links runs over them. Each link is a pair of plates with a roller (radius 0.6 cm) on its pin, the links are hinged on the pins, and the last pin closes the loop. The chain is free in its plane and only the wheels hold it. The left wheel is turned counter-clockwise at 20 rpm (the one driven joint) and drives the chain by its teeth on the rollers. The chain drives the right wheel, which carries a load (a damper). Only the teeth and the rollers touch.

Measured

The driven wheel follows the driver tooth for tooth: ratio 1.0012 (slip -0.12%) over 1 to 5.5 s, the driver at 2.06 rad/s. The chain runs round both wheels. The deepest contact is 0.19 mm.

Notes

Brown gives no sizes. The wheels are equal, so the ratio is 1; the teeth and rollers carry the drive in both directions, one wheel driving the chain and the chain driving the other.

Film (MP4) · Still (PNG) · Spec (YAML) · Model (MJCF)