The double rack-frame, B, is suspended from the rod, A. Continuous…
The double rack-frame, B, is suspended from the rod, A. Continuous rotary motion is given to the cam, D. When the shaft of the cam is midway between the two racks, the cam acts upon neither of them; but by raising or lowering the rod, A, either the lower or upper rack is brought within range of the cam, and the rack-frame moved to the left or right. This movement has been used in connection with the governor of an engine, the rod, A, being connected with the governor, and the rack-frame with the throttle or regulating valve.
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
- The cam D has one rounded tooth (tip radius 3.0) and turns clockwise at 60 rpm; it is the only driven joint. B is a frame with two racks of V teeth (2.4 cm pitch, 1.4 deep), one above D's shaft and one below, their tips 3.45 cm from it. B hangs by two rollers on a rail at the foot of rod A and slides along it against a little friction (the valve). A slides up and down in its guides, held by a stiff spring (10 kN/m) whose rest the hand sets, standing in for the governor. A is lowered 1.3 cm at 2.25 s, raised 1.3 cm at 5.75 s and returned to the middle at 14.75 s. Each change comes a quarter turn after the tooth points down, so the tooth is level and clear of both racks. The V teeth centre the rack on the tooth as it enters, so B goes a whole tooth each turn.
- Measured
- A in the middle (0.3 to 1.9 s and 15.45 to 16.9 s): B stands (mean speed 0). Lowered: 0.00380 m/rad to the right vs p/2pi = 0.00382 (-0.47%), over 2.8 to 4.8 s. Raised: -0.00380 m/rad to the left (-0.59%), over 7.3 to 14.3 s. B runs from 0 to +10.4 cm and back to -10.7 cm. Max penetration 0.14 mm.
- Notes
- The governor is not drawn; it acts through the hand schedule on A's spring rest, the operator's hand as in Nos. 5 and 56, never a drive. The first kick after lowering carries B 3.6 cm, not 2.4, because the tooth enters part-way; the checks start after it.
Film (MP4) · GIF · Still (PNG) · Spec (YAML) · Model (MJCF)
