This page now separates a connected multi-blade wind-pump topology from an exact ideal displacement ledger based only on declared wheel speed, gear ratio, pump bore, stroke and lift. It does not predict wind performance, actual water delivery or installation suitability.
Declared Wind-Pump Displacement Explorer
Enter declared wheel speed, back-gear ratio, cylinder bore, pump stroke and lift. The connected view shows wheel, gearing, crank, constant-length rod, guided sucker rod and single-acting cylinder while the worksheet reports ideal geometry and lift-energy identities.
Equation Used
- Wheel speed, gear ratio, cylinder bore, pump stroke and lift are declared inputs.
- One crank revolution produces one complete reciprocating cycle and one ideal single-acting pumping stroke.
- The ideal displaced volume equals circular piston area times full stroke.
- Water density is 1000 kg/m³ and standard gravity is 9.80665 m/s² for the ideal lift-power identity.
- The connected animation uses fixed illustrative display geometry; its crank-slider rod length is exact but not a machine dimension.
- Wind resource, rotor torque and power curve, start speed, furling, gusts, tower and well structure, gearbox and bearing losses, pump leakage and filling, valves, rod stretch and weight, acceleration, friction, efficiency, actual delivery, cavitation, drawdown, pipe loss, fatigue, maintenance and safe installation are excluded.
Replaces an unsupported calibrated cubic wind-output model with an exact declared single-acting displacement ledger and connected geared wind-pump geometry.
A multi-blade wheel drives a geared reciprocating rod pump
Manufacturer and government sources describe a wind wheel connected through back gearing to a crank or eccentric that moves a sucker rod. The rod operates a submerged plunger and check valves; in a single-acting arrangement, one pumping stroke occurs per reciprocating cycle.
The animation keeps wheel, gears, crank, connecting rod, guided sucker rod and cylinder connected. Its dimensions are illustrative.
Use this page only to audit declared displacement
The worksheet checks how declared wheel speed and gear ratio map to crank cycles, then multiplies circular piston area by stroke and pumping rate. It also reports the ideal hydraulic power associated with lifting that ideal flow through a declared height.
It cannot estimate a site's wind resource, choose a mill or pump, predict actual delivery or validate a well installation.
Separate swept displacement from wind performance
Use consistent units. The calculator converts inches, gallons, feet and hours internally. The result is ideal single-acting displacement before all volumetric and mechanical losses.
A transparent declared-geometry example
For 30 wheel rpm, a 3.00:1 reduction, 2.5 in bore and 8 in stroke, crank rate is 10.00 strokes per minute. Ideal volume is 0.170 gal per pumping stroke and ideal flow is 102.0 gal/h. At 100 ft declared lift, ideal hydraulic lift power is about 32.1 W.
No actual windmill output or equipment suitability follows from those ideal values.
Ideal displacement is not actual water delivery
Real performance depends on the wind-speed distribution, rotor power and torque curves, starting and furling behavior, wheel diameter and solidity, gearbox losses, pump filling and leakage, valves, sucker-rod stretch and weight, acceleration, pipe friction, water level and drawdown, tower and well structure, condition and installation.
The former cubic wind-speed scaling, fixed tip-speed ratio, arbitrary rpm cap, universal cut-in claim, calibrated flow prediction, sizing advice, service claims and named deployments are removed because they do not describe one verified mill, pump and site.
Prairie wind-pump ledger questions
Is ideal flow the water a real mill will deliver?
No. It is swept displacement only.
Does the entered wheel speed come from the wind?
No. It is a declared input; this page does not solve rotor aerodynamics.
Why divide wheel rpm by the gear ratio?
The ratio is declared as wheel revolutions per crank revolution. A representative historical Aermotor description reports about three wheel revolutions per pump stroke.
Can this size a windmill or well pump?
No.
Prairie wind-mill references
- USGS Open-File Report 79-1264: reciprocating rod-pump topology, single-acting delivery and capacity variables.
- USDA NRCS Windmill Data Sheet: conditional approximate capacities by mill and cylinder size.
- Aermotor, How a Windmill Pumps Water: geared wheel, sucker rod, plunger and check-valve sequence.
- Aermotor history: representative back gearing at about three wheel revolutions per pump stroke.
- NASA Glenn, Bore and Stroke: circular piston area and swept-volume identity.
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