507 Mechanical Movements

70

The driving-wheel, C, has a rim, shown in dotted outline, the…

The driving-wheel, C, has a rim, shown in dotted outline, the exterior of which serves as a bearing and stop for the studs on the other wheel, A, when the tappet, B, is out of contact with the studs. An opening in this rim serves to allow one stud to pass in and another to pass out. The tappet is opposite the middle of this opening.

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
Driving wheel C (front) carries a tappet B and a rim whose exterior is a bearing for two adjacent studs of wheel A (12 studs), locking A while B is out of contact. The rim opening (37 deg) is carved by sweeping the stud path during the push, so one stud passes in and one out; the tappet sits opposite the middle of the opening. Only j_c is driven; A moves only by tappet/stud and stud/rim contact.
Measured
Ratio j_a/j_c 0.0835 vs 1/12 = 0.08333 (-0.21% slip measured over three whole turns of C, mid-dwell to mid-dwell); A still in dwell (mean
Notes
0.0000 < 0.005); max penetration 0.05 mm.

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

Figure 70 from Brown, 1868
Brown's figure 70 (1868)