507 Mechanical Movements

10

Variable Speed Nonlinear Cone Pulleys

Is a modification of 9, the pulleys being of different shape.

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
band (friction; 120-link flat band on curved cones, collided as stacks of frustum hulls; no fork, as in the plate)
Measured
band wide 1.169 (radii 1.132; pitch-line radius r+t/2 gives the excess), plate 0.628 (0.599), narrow 0.392 (0.393), 3.0:1 over the traverse; belt dev 0.58, lateral 1.70; μ≈0 control 0.000 / 0.002 / −0.003
Notes
Only the upper pulley is motor-driven. The band position is a passive variant (all three tested, `test_010_variants_vary_the_speed_nonlinearly`).

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

Figure 10 from Brown, 1868
Brown's figure 10 (1868)