Variable rotary motion produced by uniform rotary motion
Variable rotary motion produced by uniform rotary motion. The small spur-pinion works in a slot cut in the bar, which turns loosely upon the shaft of the elliptical gear. The bearing of the pinion-shaft has applied to it a spring, which keeps it engaged; the slot in the bar is to allow for the variation of length of radius of the elliptical gear.
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
- an elliptical gear (12 × 8, 40 teeth) on its centre; a 12-tooth pinion in a carriage sliding in a slotted bar that hangs loosely on the gear's shaft, pressed in by a spring (200 N/m) and its weight
- Measured
- mean ω_gear/ω_pinion = -0.3008 over one gear turn (12/40 = 0.3), slice means -0.388..-0.212 (r_p/R: 0.379..0.253)
- Notes
- Only the pinion is motor-driven (a uniform 30 rpm in its bearing); the carriage rides 4 cm up and down the slot. Negative control: gear teeth out of contact → the gear stands (0.0000).
Film (MP4) · GIF · Still (PNG) · Spec (YAML) · Model (MJCF)
