Progressing cavity pump - Revision history

Apm: Category:Far term target

2026-03-29T19:41:02Z

← Older revision		Revision as of 21:41, 29 March 2026
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	* http://www2.mat.dtu.dk/people/J.Gravesen/MoineauPump/ ( nice page explaining the math - on internet archive too )		* http://www2.mat.dtu.dk/people/J.Gravesen/MoineauPump/ ( nice page explaining the math - on internet archive too )
	* http://www2.mat.dtu.dk/people/J.Gravesen/MoineauPump/HypoEpi4_3.html		* http://www2.mat.dtu.dk/people/J.Gravesen/MoineauPump/HypoEpi4_3.html

			[[Category:Far term target]]

Apm: /* Possible disadvantages of piston based positive displacement pumps */ added a point on pulsed pumping

2025-06-27T16:00:01Z

Possible disadvantages of piston based positive displacement pumps: added a point on pulsed pumping

← Older revision		Revision as of 18:00, 27 June 2025
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	* Possibly squeezed gas or liquid atoms (though the high thermals speeds compared to pump speeds might make that unlikely)		* Possibly squeezed gas or liquid atoms (though the high thermals speeds compared to pump speeds might make that unlikely)
	* Possibly more (complex) vibrations though PCP pumps feature two orthogonal 90° phase shifted reciprocative motions too. The wobbling.		* Possibly more (complex) vibrations though PCP pumps feature two orthogonal 90° phase shifted reciprocative motions too. The wobbling.
			* Pulsed pumping (additional to the more complex reciprocative crankshaft accelerations). <br>PCPs have completely continuous flow instead which is amazing.

	== Ideas ==		== Ideas ==

Apm: /* Math for pump throughput */

2025-06-27T15:56:11Z

Math for pump throughput

← Older revision		Revision as of 17:56, 27 June 2025
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	The gear profiles are just hectically twisted after all.		The gear profiles are just hectically twisted after all.

	{{wikitodo\| ~~add~~ the math for the volumetric flow based on: rolling radius, rotor teeth number, rotation frequency.}}		{{wikitodo\|Add the math for the volumetric flow based on: rolling radius, rotor teeth number, rotation frequency.}}

	== Related ==		== Related ==

Apm: added section == Math for pump throughput == and wikitodo

2025-06-27T15:55:47Z

added section == Math for pump throughput == and wikitodo

← Older revision		Revision as of 17:55, 27 June 2025
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	{{wikitodo\|Add gif and OpenSCAD code.}}		{{wikitodo\|Add gif and OpenSCAD code.}}

			== Math for pump throughput ==

			Despite the complex looking geometry it is suprisingly easy to calculate the chamber volume per length of pump.
			This is because the cross sectional area between outer ring gear and inner rotor gear is the same at aver y height.
			The gear profiles are just hectically twisted after all.

			{{wikitodo\| add the math for the volumetric flow based on: rolling radius, rotor teeth number, rotation frequency.}}

	== Related ==		== Related ==

Apm: /* Ideas */

2025-03-25T16:22:43Z

Ideas

← Older revision		Revision as of 18:22, 25 March 2025
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	Though this works better at larger scales due to falling viscosity issues. <br>		Though this works better at larger scales due to falling viscosity issues. <br>
	Low pressure hydrogen or helium might work for nanoscale - to analyze. <br>		Low pressure hydrogen or helium might work for nanoscale - to analyze. <br>

			{{wikitodo\|Add gif and OpenSCAD code.}}

	== Related ==		== Related ==

Apm: /* Usage as motor with inherent direct geardown */

2025-03-25T16:21:55Z

Usage as motor with inherent direct geardown

← Older revision		Revision as of 18:21, 25 March 2025
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	== Ideas ==		== Ideas ==

	=== Usage as motor with inherent direct geardown ===		=== Usage as motor with inherent-direct-geardown and self-cooling ===

	The concept could be reversed and used as a motor.<br>		The concept could be reversed and used as a motor.<br>

Apm: added section == Nanoscale peculiarities – biaxial curvature issue ==

2025-03-25T16:21:16Z

added section == Nanoscale peculiarities – biaxial curvature issue ==

← Older revision		Revision as of 18:21, 25 March 2025
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	more like a constant current source rather than a constant voltage source <br>		more like a constant current source rather than a constant voltage source <br>
	(given a non compressible liquid as medium). <br>		(given a non compressible liquid as medium). <br>

			== Nanoscale peculiarities – biaxial curvature issue ==

			While uniaxial bent structures are nicely possible by bending strain and systematic substitutions and such <br>
			biaxial curvature (as in spheres and the complex curvatures of PCPs) is not so easily possibly. <br>
			Advanced methods to design and [[mechanosynthesis\|mechanosynthesize]] [[quasi amorphous structure]]s could help in getting <br>
			inner walls of nanoscale atomically precise PCPs smooth to subatomic precision <br>
			thereby reducing friction and likely hood of backflow of smallest atoms and molecules like helium and hydrogen <br>

	== Vacuum applications ==		== Vacuum applications ==

Apm: changed headline hierarchy

2025-03-25T16:14:58Z

changed headline hierarchy

← Older revision		Revision as of 18:14, 25 March 2025
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	walls similar to the size of the chambers pumped down. <br>		walls similar to the size of the chambers pumped down. <br>

	== Advantage over trubomolecular pumps ==		=== Advantage over trubomolecular pumps ===

	Turbomolecular pumps need to operate near or above the speed of sound. <br>		Turbomolecular pumps need to operate near or above the speed of sound. <br>
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	Higher multipole moment(?) <br>		Higher multipole moment(?) <br>

	== Possible disadvantages of piston based positive displacement pumps ==		=== Possible disadvantages of piston based positive displacement pumps ===

	* More parts and more complex assembly		* More parts and more complex assembly
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	== Ideas ==		== Ideas ==

	== Usage as motor with inherent direct geardown ==		=== Usage as motor with inherent direct geardown ===

	The concept could be reversed and used as a motor.<br>		The concept could be reversed and used as a motor.<br>

Apm: /* Ideas */

2025-03-25T16:14:11Z

Ideas

← Older revision		Revision as of 18:14, 25 March 2025
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	== Ideas ==		== Ideas ==

			== Usage as motor with inherent direct geardown ==

	The concept could be reversed and used as a motor.<br>		The concept could be reversed and used as a motor.<br>

Apm: mote on reciprocative motions and compensation and some general cleanup

2025-03-25T16:13:02Z

mote on reciprocative motions and compensation and some general cleanup

← Older revision		Revision as of 18:13, 25 March 2025
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	~~{{stub}}~~		'''Progressing cavity pumps (PCPs) also Moineau pumps.''' <br>

	~~Progressing cavity pumps (PCPs) also Moineau pumps. <br>~~		Due to a quite astonishing and surprising geometric miracle despite …<br>

	Due to a quite astonishing and surprising geometric miracle despite <br>
	– the smooth non translatory motion and <br>		– the smooth non translatory motion and <br>
	– the continuous non pulsing transport flow <br>		– the continuous non pulsing transport flow <br>
	this is a positive displacement pump with closed chambers. <br>		this is a positive displacement pump with closed chambers. <br>
	As ~~ushc~~ it acts as a pump in the [[mechanical electrical analogy]] <br>		As such it acts as a pump in the [[mechanical electrical analogy]] <br>
	more like a constant current source rather than a constant voltage source <br>		more like a constant current source rather than a constant voltage source <br>
	(given a non compressible liquid as medium). <br>		(given a non compressible liquid as medium). <br>
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	clever geometries with interdigitating blades on the inside too likely can completely solve that <br>		clever geometries with interdigitating blades on the inside too likely can completely solve that <br>

	~~Vicosity~~ losses at near perfect vacuum are likely ~~negligable~~. <br>		Viscosity losses at near perfect vacuum are likely negligible. <br>
	For pumping at higher pressures larrger scale PCPs may be <br>		For pumping at higher pressures larrger scale PCPs may be <br>

			Note that (while not totally obvious) there are two exactly equal 90° phase shifted reciprocative motions involved. <br>
			Four PCPs need to be paired up to compensate by counter-motions and hugely reduce radiated vibrations. <br>
			Higher multipole moment(?) <br>

	== Possible disadvantages of piston based positive displacement pumps ==		== Possible disadvantages of piston based positive displacement pumps ==