Double lantern-bellows pump
Double lantern-bellows pump. As one bellows is distended by lever, air is rarefied within it, and water passes up suction-pipe to fill space; at same time other bellows is compressed, and expels its contents through discharge-pipe; valves working the same as in the ordinary force pump.
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
- Seen from in front, cut in section, as Brown. The lever turns on a fulcrum on the upright behind and is swung by hand at its right end (the only drive, ±0.25 rad, 0.27 Hz). A rod hinged on each bellows' top is pinned to the lever: the left one 11 cm out, the right one 8.5 cm, as Brown draws them. Each bellows is a lantern of 3 hoops and its top, each on a slide over the one below. The leather between them folds inward in pleats: two leaves hinged on the hoops and on each other at the crease, which draw Brown's zigzag from the sim. A light spring on each slide (the leather) shares the stroke among the pleats. The base box is split by the riser. Under each bellows a poppet on a hole in the floor admits water from the suction channel, and a flap hung on the riser's wall lets it out. Each valve is moved only by its weight and the pressures on its faces. Water is lumped vessels: each bellows with its half of the base is a closed chamber its top sweeps, and each pleat's slide is a piston of the top's area, so the sweep is the top's travel. The suction pipe and channel from a well, and the riser, are full. The riser delivers 60 cm up, beyond the frame, through an inertial pipe. gen: opencode-runs/water/gen453.py
- Measured
- Trace over 4–8 s: as the lever lifts the left bellows, its poppet opens (sL up to 438 g/s) and its pressure falls to about −3.3 kPa. Meanwhile the right bellows is pressed down to about +7.3 kPa, and its flap opens into the riser. On the return stroke the roles swap. Delivery runs on each stroke (mean 243 g/s, peak 454) and stops at each reversal. The pleats share the stroke within about 0.5 mm. A brief backflow (≤26 g/s) passes each flap as it shuts. Gate: pytest 2 passed, lint 0 FAIL, motion gate pass, no WARN.
- Notes
- Grade B+. Not in Brown: the delivery height beyond the frame, the well, and the drive speed. The suction channel is a straight box where Brown curves it into a U. The water inside each bellows is drawn as a rectangle to just inside the hoops, so the pleats' outer pockets show it a little beyond the leather. The riser stops under the lever rather than hooking over as Brown's does.
Film (MP4) · Still (PNG) · Spec (YAML) · Model (MJCF)
