For transmitting two speeds, one a differential motion
For transmitting two speeds, one a differential motion. The band is shown on a loose pulley on lower shaft. The middle pulley is fast on said shaft, and has a small bevel-gear secured to its hub. Pulley on the right, which, like that on the left, is loose on shaft, carries, transversely, another bevel-gear. A third bevel-gear, loose upon the shaft, is held by a friction-band which is weighted at the end. On moving band on middle pulley a simple motion is the result, but when it is moved to right-hand pulley a double speed is given to shaft. The friction-band or curb on the third bevel-gear is to allow it to slip a little on a sudden change of speed.
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
- Brown's figure 61: drum above (the driven shaft); below, a loose pulley, the middle pulley fast on the shaft with bevel A, the right-hand pulley loose and carrying bevel B on a transverse pin, and bevel C loose on the shaft, held by a weighted friction-band (a lever with a shoe on a drum on C's hub, held by contact friction). No. 7's bevels. The band's pulley is a passive variant
- Measured
- pass (band on the right-hand pulley): shaft/carrier 2.0003 (2), shaft/drum 1.9804, C 0.0000; max penetration 0.33 mm; passes at 20/30/40 rpm. Variants (test_061): middle pulley 0.9895 (1), loose 0.0000
- Notes
- A joint frictionloss as the curb did not hold (MuJoCo's soft friction on C's small inertia let it creep at 0.15), so the band is real: a weighted lever pressing a shoe on a drum on C's hub, held by contact friction. Upper shaft 22 above (at 30 the band spans flapped at 30 rpm), pretension 60. PGS. batch7/gen061.py. Negative control: the friction-band lifted clear → C runs back, shaft/carrier 0.219.
Film (MP4) · GIF · Still (PNG) · Spec (YAML) · Model (MJCF)
