507 Mechanical Movements

47

Frictional clutch-box

A frictional clutch-box, thrown in and out of gear by the lever at the bottom. This is used for connecting and disconnecting heavy machinery. The eye of the disk to the right has a slot which slides upon a long key or feather fixed on the shaft.

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
two shafts in line: a disk fixed on the driving shaft, the other on a feather (a slide joint along the driven shaft) with a grooved hub; the lever's fork stands in the groove and a spring holds the lever where the hand sets it: thrown in at 2 s (about 15 N on the faces), out at 5.5 s
Measured
driven/driver 0.0000 before, 0.9887 in gear (1.1% creep on the faces), 0.002 after
Notes
The flat faces drive by friction alone. Only the driving shaft is motor-driven; the hand only moves the lever's spring. Negative control: faces frictionless (μ≈0) with the lever thrown in → the driven shaft stands (0.0000).

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

Figure 47 from Brown, 1868
Brown's figure 47 (1868)