Common lift pump
Common lift pump. In the up-stroke of piston or bucket the lower valve opens and the valve in piston shuts; air is exhausted out of suction-pipe, and water rushes up to fill the vacuum. In down-stroke, lower valve is shut and valve in piston opens, and the water simply passes through the piston. The water above piston is lifted up, and runs over out of spout at each up-stroke. This pump cannot raise water over thirty feet high.
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 the front, as Brown, the pump cut away in half section: a barrel (5.8 cm bore) with a foot valve at its bottom over the suction pipe, a cistern over it with the spout on the left. The bucket (piston) carries its own valve over a hole through it; its rod rises to the handle's short end, and the handle turns on a fulcrum carried by a swinging link from a lug on the cistern, so the rod rises and falls straight. The hand swings the handle (the only drive). The water is lumped vessels: the barrel under the piston and the barrel over it are chambers the piston sweeps, the cistern is an open tank spilling out of the spout, and the suction pipe is the well's water standing about 25 cm below. Both valves are real poppets on slides, held shut by their weight and lifted only by the pressures on their two faces.
- Measured
- On each up-stroke the barrel under the piston falls to about -2.6 kPa, the foot valve lifts and water rushes up from the well while the piston's valve stays shut; the water over the piston is lifted into the cistern and runs out of the spout. On each down-stroke the foot valve shuts, the water under the piston rises to about +0.6 kPa and lifts the piston's valve, and the water passes up through the piston. About 0.54 kg is drawn up from the well and 0.50 kg runs out of the spout in 10 s of hand pumping (piston stroke about 4.4 cm).
- Notes
- The water in the barrel is a lumped chamber and is not drawn; the cistern's water and the stream off the spout are. The suction pipe is cut short, its water taken as standing 25 cm below the foot valve; the chamber stiffness allows a little air held in the barrel. Brown's limit of thirty feet (the atmosphere's pressure) is not exercised.
Film (MP4) · Still (PNG) · Spec (YAML) · Model (MJCF)
