EP2949936A1 - Diaphragm pump with hydraulic control including a dedicated degassing path - Google Patents

Diaphragm pump with hydraulic control including a dedicated degassing path Download PDF

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Publication number
EP2949936A1
EP2949936A1 EP15168751.4A EP15168751A EP2949936A1 EP 2949936 A1 EP2949936 A1 EP 2949936A1 EP 15168751 A EP15168751 A EP 15168751A EP 2949936 A1 EP2949936 A1 EP 2949936A1
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EP
European Patent Office
Prior art keywords
channel
valve
pump
path
chamber
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
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Application number
EP15168751.4A
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German (de)
French (fr)
Inventor
Yoann Chevallier
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Milton Roy Europe SA
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Milton Roy Europe SA
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Publication date
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Publication of EP2949936A1 publication Critical patent/EP2949936A1/en
Withdrawn legal-status Critical Current

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Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
    • F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
    • F04B43/00—Machines, pumps, or pumping installations having flexible working members
    • F04B43/02—Machines, pumps, or pumping installations having flexible working members having plate-like flexible members, e.g. diaphragms
    • F04B43/06—Pumps having fluid drive
    • F04B43/067—Pumps having fluid drive the fluid being actuated directly by a piston
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
    • F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
    • F04B53/00—Component parts, details or accessories not provided for in, or of interest apart from, groups F04B1/00 - F04B23/00 or F04B39/00 - F04B47/00
    • F04B53/06—Venting
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
    • F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
    • F04B53/00—Component parts, details or accessories not provided for in, or of interest apart from, groups F04B1/00 - F04B23/00 or F04B39/00 - F04B47/00
    • F04B53/10—Valves; Arrangement of valves
    • F04B53/1037—Flap valves
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
    • F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
    • F04B53/00—Component parts, details or accessories not provided for in, or of interest apart from, groups F04B1/00 - F04B23/00 or F04B39/00 - F04B47/00
    • F04B53/14—Pistons, piston-rods or piston-rod connections

Definitions

  • Hydraulically controlled diaphragm pumps usually comprise a dosing head comprising a first part having a pumping chamber and a second part in which is formed a hydraulic chamber which is filled with a hydraulic control fluid and which is separated from the chamber pumping by a membrane; and a metering body comprising drive means in translation of a piston of the pump in the hydraulic chamber along a given axis of translation.
  • Said valve is typically arranged in the vicinity of an uppermost point of the hydraulic chamber in the working position of the pump and comprises a hollow body in communication with the hydraulic chamber via a calibrated valve, the valve opening, when the pressure in the hydraulic chamber exceeds a threshold pressure, to evacuate a portion of the fluid from the hydraulic chamber to the hollow body of the valve.
  • the valve may allow degassing of the air bubbles present in the hydraulic chamber.
  • the degassing is limited due in particular to the reduced sections of the channels connecting the hydraulic chamber to the hollow body of the valve. Bubbles may therefore in some cases remain stuck in the hydraulic chamber or in the channels connecting said chamber to the hollow body of the valve. This is for example the case for pumps in which the metering body is filled with air which causes a slight air intake into the hydraulic chamber at each piston translation movement and therefore a relatively large concentration of bubbles in the hydraulic chamber.
  • An object of the invention is to provide a hydraulically controlled diaphragm pump capable of allowing continuous and significant degassing of the gases present in the hydraulic control fluid.
  • the pump comprises a dedicated degassing path placed closer to the border between the metering body and the second part.
  • the air passing from the metering body to the second part with each translational movement of the piston is easily discharged to the hollow body of the valve. This allows a continuous and important degassing of the pump.
  • the pump is thus very powerful and has consistent performance over time.
  • the invention is particularly suitable for low flow pumps since they are more sensitive to the presence of air in their hydraulic chamber.
  • the hydraulic control diaphragm pump according to the invention is here a pump low flow and medium or high pressure.
  • the pump comprises a metering head 1 comprising a first part 2 which defines with a membrane 3 of the pump a pumping chamber 4.
  • the pumping chamber 4 is connected to the outside by a suction channel 5 and a channel 6, which are equipped with unidirectional valves contained in valve boxes.
  • the membrane 3 is here a thick membrane.
  • the membrane 3 is elastically deformable from its rest form (the one shown) which corresponds to its state at the end of the suction stroke of the pump.
  • the stiffness of this membrane 3 is such that the suction power of the pump is defined by the capacity of the membrane 3 to return by itself to its rest position.
  • Such a membrane is well known from the prior art, as for example in the application FR 2 934 332 of the plaintiff, and will not be further detailed here.
  • the metering head 1 further comprises a second portion 7 in which a hydraulic chamber 8 is formed.
  • the face of the membrane 3 opposite to that facing the pumping chamber 4 is called the rear face and is exposed to the pressure of the hydraulic fluid. which prevails in the hydraulic chamber 8.
  • Channels for passage 23 of the hydraulic fluid of the hydraulic chamber 8 for reaching the rear face of the membrane 3 are also provided in the second part 7.
  • the second portion 7 further comprises a liner 9 extending in the second portion 7 along a horizontal axis X so that a first end 9a of the liner 9 faces the membrane 3 and a second end 9b of the The liner 9 opens out of the second portion 7.
  • the liner 9 has a local constriction 10 of its outer section defining with the second portion 7 a dewatering chamber 11.
  • the second portion 7 further comprises a drain channel 12 connecting said emptying chamber 11 to the outside of the pump.
  • the drain channel 12 extends vertically in the second part 7 of the emptying chamber 11 at the lower end of the second part 7.
  • the pump further comprises a piston 13 which is received in the liner 9 and which extends along said axis X so that a first end 13a of the piston opens into the hydraulic chamber 8 and a second end 13b of the piston 13 opens out of the shirt 9.
  • the piston 13 is mechanically driven by translation drive means comprising a motor and a transmission, known in themselves and which are not represented here in full, so that the piston 13 can perform a translational movement in the hydraulic chamber 8 along said axis X.
  • translation drive means comprising a motor and a transmission, known in themselves and which are not represented here in full, so that the piston 13 can perform a translational movement in the hydraulic chamber 8 along said axis X.
  • the drive means in translation of the piston 13 are arranged in a metering body 14 of the pump. More precisely here the metering body 14 comprises a cavity 15 adjacent to the second part 7 and in which the second end 13b of the piston 13 is connected to the drive means in translation, said cavity 15 being in the open air.
  • the second part 7 is here secured to the metering body 14 via the second end 9b of the liner 9 thus defining the boundary between the second portion 7 and the metering body 14.
  • the metering body 14 being filled with air while the second part 7 is filled with a hydraulic control fluid, it is necessary to ensure a seal of the second part 7.
  • the pump thus comprises a seal 16 arranged on the piston 13 at a junction between the second portion 7 and the metering body 14.
  • a housing is formed in the second end 9b of the liner 9 and the seal 16 is arranged at the interior of said housing.
  • the seal 16 is here a lip seal.
  • the pump thus has little hydraulic control fluid.
  • the pump further comprises a pressure regulating valve 17 in the hydraulic chamber 8.
  • the valve 17 is here arranged on the second part 7 in the vicinity of an uppermost point of the hydraulic chamber 8 in the working position of the pump.
  • the valve 17 extends vertically and comprises a lower portion 18 resting in a housing 19 formed in the second portion 7 above the liner 9 and an upper portion 20 resting on the lower portion 18 and extending in part only in said housing 19.
  • a lower end of the upper portion 20 here has an internal thread 21 for attachment to the lower portion 18 and an external thread 22 for attachment to the second portion 7.
  • the valve 17 further comprises a discharge valve 24 which is tared.
  • the valve 24 is here arranged in the valve at the boundary between the lower portion and the upper portion.
  • the valve 24 delimits with the upper portion 20 a hollow body 25.
  • the valve 24 is configured to be passing in the direction from the hydraulic chamber 8 to the hollow body 25 if the pressure in the hydraulic chamber 8 exceeds a threshold value adjustable by setting the calibration of the valve 24, for example by means of a screw.
  • the valve 17 further comprises a main channel 26 formed in the lower portion 18 to open under the valve 24 and connected to the hydraulic chamber 8 by a conduit 27 formed in the second part.
  • the hydraulic control fluid contained in the hydraulic chamber 8 can be discharged from said hydraulic chamber 8 via the main channel 26 and the discharge valve 24 to open into the hollow body 25.
  • the valve 17 thus reduces excessive pressure in the hydraulic chamber 8.
  • the hydraulic control fluid contained in the hydraulic chamber 8 sees its volume vary especially during an exhaust of the fluid from the hydraulic chamber 8 by the valve 24 or because of the air bubbles that appear during the movements piston 13 in the hydraulic chamber 8 or because of the variation of the adjustable stroke of the pump which varies the stroke of the piston 13 and thus the displacement of the pump.
  • the valve 17 comprises means for compensating the leakage of the hydraulic control fluid in the hydraulic chamber 8.
  • said means comprise a feedback path which connects the hollow body 25 to the main channel 26 bypassing the valve 24.
  • the feedback path here comprises a first feedback channel 28 extending vertically to through the lower portion 18 between the hollow body 25 and a replenishment volume 29 which is delimited by the low end of the lower portion 18 on the one hand and the corresponding housing 19 of the second part 7 on the other.
  • Said refeeding path further includes a second channel 30 extending vertically from said replenishment volume 29 to the main channel 26.
  • the second channel 30 further comprises two ball valves 31 in series and in series, unidirectional, free, the direction of these two valves 31 being that going from the hollow body 25 to the hydraulic chamber 8.
  • a stroke towards the rear of the piston 13 allows the elastic return of the membrane 3 in its rest position. If this position is reached before the piston 13 has reached its rear dead point, there is a depression in the hydraulic chamber 8 which results in the suction of a volume of the hydraulic fluid withdrawn from the hollow body 25 through the two Valves in series 31.
  • the valve 17 thus makes it possible to regulate also a too low pressure in the hydraulic chamber 8.
  • the valve 17 further comprises a purge passage 32 arranged in a bypass of the valve 24 which allows a continuous purge of the air bubbles possibly present in the hydraulic chamber 8, the air passing through the main channel 26 and said passage purge 32 to result in the hollow body. Part of the air bubbles is thus evacuated via the main channel 26.
  • the main channel 26 is arranged above the hydraulic chamber 8 so as to take advantage of the natural accumulation of air at the high point of said hydraulic chamber 8 to facilitate the purge of the air bubbles contained in the hydraulic chamber 8 in the valve 17.
  • the pump further comprises degassing means dedicated to the hydraulic control fluid.
  • the dedicated degassing means comprise a degassing path extending into the second part 7.
  • the degassing path here comprises a first channel 33 extending transversely in the jacket 9 so as to open at its lower end at a junction zone between the piston and the seal and to open at its upper end in the chamber 11.
  • the first channel 33 is thus arranged closer to the air inlet zone from the metering body 14 to collect said air.
  • the first channel 33 thus extends here in the direction of the valve 17 and transversely to the axis X.
  • the degassing path comprises a second channel 34 extending transversely in the second portion 7 so as to open at its lower end in the emptying chamber 11 and at its upper end in the open air which facilitates its machining.
  • the upper end of the second channel 34 is however closed by a plug 35.
  • the second channel 34 is arranged so as to open at its lower end in the emptying chamber 11 in the upper part of the emptying chamber 11 substantially at the same level as the upper end of the first channel 33.
  • the first channel 33 and the second channel 34 are thus connected via the emptying chamber 11.
  • the second channel 34 is arranged so that its lower end opens out. above the high end of the first channel 33 which ensures a better connection between the two channels and thus a more effective degassing.
  • the second channel 34 thus extends here in the opposite direction of the valve 17 transversely to the axis X.
  • the degassing path further comprises a third channel 36 extending transversely in the second portion 7 so as to open at its lower end in the second channel 34 at the upper end of said second channel 34 and at its upper end in the housing 19 receiving the valve 17.
  • the third channel 36 extends here in the direction of the valve 17 and transversely to the axis X.
  • the degassing path further comprises a fourth channel 37 extending through one of the walls of the upper portion 20 of the valve so as to be connected at a first end to the upper end of the third channel 36 and to open at its second end in the hollow body 25.
  • the fourth channel 37 extends here substantially horizontally.
  • the lower end of the first channel 33 forms the first end of the degassing path and is located at the lowest point of said path while the second end of the fourth channel 37 forms the second end of the degassing path and is located at the the highest of the said path.
  • the air coming from the metering body 14 is purged continuously by the degassing path, the air successively passing through the first channel 33, the second channel 34, the third channel 36 and the fourth channel 37
  • the degassing path removes the air directly at the seal 16 so that little or no air from the metering body 14 reaches the hydraulic chamber 8. This avoids degrading the performance of the pump.
  • the degassing path opening into the upper portion 20 of the valve 17 little or no air is present in the feed path which ensures that no bubble or almost is sent into the hydraulic chamber 8 when a phase of compensation of leakage of the hydraulic fluid in the hydraulic chamber 8.
  • the dedicated degassing means thus allow a very effective and continuous degassing of the air present in the hydraulic fluid.
  • the degassing path is here shaped so as to convey the air into the valve 17 by opening into the valve 17 substantially above the valve 24.
  • the degassing path is shaped so that the volume of hydraulic fluid between the fourth channel 37 (opening into the valve 17) and the replenishment volume 29 is greater than a maximum displacement of the pump.
  • the different channels of the degassing path have a larger section than the channels connecting the hydraulic chamber 8 to the valve 17 and the main channel 26.
  • the section of said channels degassing path can prevent bubbles from remain trapped inside said degassing path, the bubbles to be evacuated being more numerous in the degassing path.
  • the second channel 34 of the degassing path further has a larger section than the first channel 33, the third channel 36 and the fourth channel 37 of the degassing path.
  • the second channel 34 of the degassing path typically has a section 2 to 4 times larger than that of the first channel 33 of the degassing path. This effectively discharges the bubbles from the first channel 33 to the third channel 36.
  • the hydraulic control fluid is present only in the second part 7.
  • the fluid is thus present and under pressure in the hydraulic chamber 8, the passage channels 23, the conduit 27 connecting the hydraulic chamber 8 to the valve 17 and the main channel 26.
  • the fluid is also present at a pressure less than or equal to the atmospheric pressure in the remainder of the valve 17 (hollow body 25 and feed path), in the degassing path, in the drain chamber 11 and in the drain channel 12.
  • Most of the air to be degassed is at the junction between the second part 7 and the metering body. 14 and is evacuated by the degassing path and is in a minority (or even nonexistent) in the hydraulic chamber 8 and is preferably evacuated by the valve 17 and in particular the main channel 26 and the purge passage 32.
  • the pump according to the invention thus allows an effective and continuous degassing of the air present in the hydraulic fluid and avoids the presence of too much air bubbles in the hydraulic chamber 8.
  • the flow rate of the pump according to the invention the invention thus proves to be regular, precise and stable.
  • the pump may have another shape than that described.
  • a connection channel 140 of the emptying chamber 111 to the feed path is formed in the second Part 107.
  • said connection channel 140 opens at the bottom of the feed path here in the feed volume 129. This does not unduly affect the good degassing by the degassing path because of the optimized arrangement between the first channel 133 and the second channel 134 of said degassing path which ensures that the air bubbles rise preferentially through the second channel 134 rather than by the connection channel 140.
  • the degassing path may also have any other shape than indicated: said path may thus comprise a different number of channels and said channels may be oriented differently.
  • said second channel may extend vertically or extend transversely towards the valve.
  • the first channel and the second channel can be connected to each other without the intermediary of the emptying chamber.
  • the dedicated degassing means may include several degassing paths.
  • valve may have any other shape than that indicated.
  • the valve may thus be a valve as described in the application EP 2 394 056 of the present applicant.
  • the membrane may be different from what has been described.
  • the membrane may thus be a composite membrane comprising a thick inner wall surrounded by two thin metal walls as described in the applications FR 2,670,537 and FR 2 934 332 of the plaintiff.
  • the pump may further comprise a device for detecting rupture of the membrane.
  • the valve may comprise any other known control hydraulic fluid degassing device than the purge passage described.

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Reciprocating Pumps (AREA)
  • Details Of Reciprocating Pumps (AREA)

Abstract

L'invention concerne une pompe comportant une tête de dosage (1) comprenant une première partie (2) et une deuxième partie (7) dans laquelle est ménagée une chambre hydraulique (8) qui est remplie d'un fluide et un corps de dosage (14) comprenant des moyens d'entraînement en translation d'un piston (13) de la pompe dans la chambre hydraulique, une soupape (17) de régularisation de pression dans la chambre hydraulique et au moins un chemin de dégazage (33, 34, 36, 37) s'étendant dans la deuxième partie de sorte qu'une première extrémité du chemin formant le point le plus bas dudit chemin débouche au niveau d'une jonction entre le piston et un joint monté sur le piston et qu'une deuxième extrémité du chemin formant le point le plus haut dudit chemin débouche dans un corps creux de ladite soupape.The invention relates to a pump comprising a dosing head (1) comprising a first part (2) and a second part (7) in which is formed a hydraulic chamber (8) which is filled with a fluid and a metering body (14) comprising drive means for translating a piston (13) of the pump into the hydraulic chamber, a valve (17) for regulating the pressure in the hydraulic chamber and at least one degassing path (33, 34 , 36, 37) extending into the second portion so that a first end of the path forming the lowest point of said path opens at a junction between the piston and a seal mounted on the piston and that a second end of the path forming the highest point of said path opens into a hollow body of said valve.

Description

Les pompes à membrane à commande hydraulique comportent usuellement une tête de dosage comprenant une première partie ayant une chambre de pompage et une deuxième partie dans laquelle est ménagée une chambre hydraulique qui est remplie d'un fluide hydraulique de commande et qui est séparée de la chambre de pompage par une membrane ; ainsi qu'un corps de dosage comprenant des moyens d'entraînement en translation d'un piston de la pompe dans la chambre hydraulique selon un axe de translation donné.Hydraulically controlled diaphragm pumps usually comprise a dosing head comprising a first part having a pumping chamber and a second part in which is formed a hydraulic chamber which is filled with a hydraulic control fluid and which is separated from the chamber pumping by a membrane; and a metering body comprising drive means in translation of a piston of the pump in the hydraulic chamber along a given axis of translation.

Il est courant d'équiper lesdites pompes d'une soupape de régularisation de pression dans la chambre hydraulique afin d'éviter notamment tout endommagement de la membrane ou un blocage de la pompe. Ladite soupape est typiquement agencée au voisinage d'un point le plus haut de la chambre hydraulique dans la position de travail de la pompe et comporte un corps creux en communication avec la chambre hydraulique via un clapet taré, le clapet s'ouvrant, lorsque la pression dans la chambre hydraulique dépasse une pression seuil, pour évacuer une partie du fluide de la chambre hydraulique vers le corps creux de la soupape.It is common to equip said pumps with a pressure equalization valve in the hydraulic chamber in order to avoid any damage to the membrane or blockage of the pump. Said valve is typically arranged in the vicinity of an uppermost point of the hydraulic chamber in the working position of the pump and comprises a hollow body in communication with the hydraulic chamber via a calibrated valve, the valve opening, when the pressure in the hydraulic chamber exceeds a threshold pressure, to evacuate a portion of the fluid from the hydraulic chamber to the hollow body of the valve.

Accessoirement, la soupape peut permettre un dégazage des bulles d'air présentes dans la chambre hydraulique.Incidentally, the valve may allow degassing of the air bubbles present in the hydraulic chamber.

Toutefois, le dégazage s'avère limité du fait notamment des sections réduites des canaux reliant la chambre hydraulique au corps creux de la soupape. Des bulles peuvent donc dans certains cas demeurer coincées dans la chambre hydraulique ou dans les canaux reliant ladite chambre au corps creux de la soupape. Ceci est par exemple le cas pour les pompes dans lesquelles le corps de dosage est rempli d'air ce qui provoque une légère admission d'air dans la chambre hydraulique à chaque mouvement de translation du piston et donc une concentration relativement importante de bulles dans la chambre hydraulique.However, the degassing is limited due in particular to the reduced sections of the channels connecting the hydraulic chamber to the hollow body of the valve. Bubbles may therefore in some cases remain stuck in the hydraulic chamber or in the channels connecting said chamber to the hollow body of the valve. This is for example the case for pumps in which the metering body is filled with air which causes a slight air intake into the hydraulic chamber at each piston translation movement and therefore a relatively large concentration of bubbles in the hydraulic chamber.

Or, la présence de bulles d'air dans le fluide au niveau de la chambre hydraulique et dans les canaux en liaison avec la chambre hydraulique tend à dégrader fortement les performances des pompes entraînant notamment une perte importante de leur débit. Cet inconvénient est encore augmenté pour les pompes de petits débits.However, the presence of air bubbles in the fluid at the hydraulic chamber and in the channels in connection with the hydraulic chamber tends to severely degrade the performance of the pumps including a significant loss of their flow. This disadvantage is further increased for small flow pumps.

OBJET DE L'INVENTIONOBJECT OF THE INVENTION

Un but de l'invention est de proposer une pompe à membrane à commande hydraulique apte à permettre un dégazage continu et important des gaz présents dans le fluide hydraulique de commande.An object of the invention is to provide a hydraulically controlled diaphragm pump capable of allowing continuous and significant degassing of the gases present in the hydraulic control fluid.

BREVE DESCRIPTION DE L'INVENTIONBRIEF DESCRIPTION OF THE INVENTION

En vue de la réalisation de ce but, on propose une pompe à membrane à commande hydraulique comportant :

  • une tête de dosage comprenant une première partie ayant une chambre de pompage et une deuxième partie dans laquelle est ménagée une chambre hydraulique qui est remplie d'un fluide hydraulique de commande et qui est séparée de la chambre de pompage par une membrane,
  • un corps de dosage comprenant des moyens d'entraînement en translation d'un piston de la pompe dans la chambre hydraulique selon un axe de translation,
  • au moins un joint d'étanchéité agencé sur le piston au niveau d'une jonction entre la deuxième partie et le corps de dosage,
  • une soupape de régularisation de pression agencée au voisinage d'un point le plus haut de la chambre hydraulique dans la position de travail de la pompe, la soupape ayant un corps creux en communication avec la chambre hydraulique via un clapet qui est passant dans le sens de la chambre hydraulique vers le corps creux,
  • des moyens de dégazage dédiés du fluide, lesdits moyens comprenant au moins un chemin de dégazage s'étendant dans la deuxième partie non parallèlement à l'axe de translation de sorte qu'une première extrémité du chemin formant le point le plus bas dudit chemin débouche au niveau d'une jonction entre le piston et le joint et qu'une deuxième extrémité du chemin formant le point le plus haut dudit chemin débouche dans le corps de soupape au-dessus du clapet.
In order to achieve this goal, a hydraulically operated diaphragm pump is provided comprising:
  • a metering head comprising a first part having a pumping chamber and a second part in which is formed a hydraulic chamber which is filled with a hydraulic control fluid and which is separated from the pumping chamber by a membrane,
  • a metering body comprising drive means in translation of a piston of the pump in the hydraulic chamber along a translation axis,
  • at least one seal arranged on the piston at a junction between the second part and the metering body,
  • a pressure regulating valve arranged in the vicinity of an uppermost point of the hydraulic chamber in the working position of the pump, the valve having a hollow body in communication with the hydraulic chamber via a valve which is passing in the direction from the hydraulic chamber to the hollow body,
  • dedicated degassing means of the fluid, said means comprising at least one degassing path extending in the second part not parallel to the translation axis so that a first end of the path forming the lowest point of said path opens at a junction between the piston and the seal and that a second end of the path forming the highest point of said path opens into the valve body above the valve.

Ainsi, la pompe comporte un chemin de dégazage dédié placé au plus près de la frontière entre le corps de dosage et la deuxième partie. L'air passant du corps de dosage à la deuxième partie à chaque mouvement de translation du piston est donc aisément évacué vers le corps creux de la soupape. Ceci permet un dégazage continu et important de la pompe.Thus, the pump comprises a dedicated degassing path placed closer to the border between the metering body and the second part. The air passing from the metering body to the second part with each translational movement of the piston is easily discharged to the hollow body of the valve. This allows a continuous and important degassing of the pump.

Ceci limite en outre le transfert de bulles d'air du corps de dosage à la chambre hydraulique. La quantité de bulles d'air dans la chambre hydraulique demeure donc limitée voire nulle.This further limits the transfer of air bubbles from the metering body to the hydraulic chamber. The amount of air bubbles in the hydraulic chamber therefore remains limited or even zero.

La pompe s'avère ainsi très performante et présente des performances constantes dans le temps.The pump is thus very powerful and has consistent performance over time.

L'invention est particulièrement adaptée aux pompes à faibles débits puisqu'elles sont plus sensibles à la présence d'air dans leur chambre hydraulique.The invention is particularly suitable for low flow pumps since they are more sensitive to the presence of air in their hydraulic chamber.

Pour la présente demande, les termes « point haut », « point bas », « inférieur », « supérieur », « dessus » ... sont bien entendu à entendre par référence à la position en service de la pompe c'est-à-dire la position dans laquelle la pompe repose sur un support et la soupape est agencée pour s'étendre en direction opposée de ce support.For the present application, the terms "high point", "low point", "lower", "upper", "above" ... are of course to be understood by reference to the operating position of the pump. ie the position in which the pump rests on a support and the valve is arranged to extend in the opposite direction of this support.

BREVE DESCRIPTION DES DESSINSBRIEF DESCRIPTION OF THE DRAWINGS

L'invention sera mieux comprise à la lumière de la description qui suit d'un mode de réalisation particulier, non limitatif, de l'invention. Il sera fait référence aux figures ci-jointes, parmi lesquelles :

  • la figure 1 est une vue en coupe d'une pompe à membrane à commande hydraulique selon l'invention, une partie seulement du corps de dosage étant représenté,
  • la figure 2 est une vue en coupe d'une partie d'une pompe à membrane à commande hydraulique selon une variante de l'invention.
The invention will be better understood in the light of the following description of a particular, non-limiting embodiment of the invention. Reference will be made to attached figures, among which:
  • the figure 1 is a sectional view of a hydraulically controlled diaphragm pump according to the invention, only part of the metering body being shown,
  • the figure 2 is a sectional view of a portion of a hydraulically operated diaphragm pump according to a variant of the invention.

DESCRIPTION DETAILLEE DE L'INVENTIONDETAILED DESCRIPTION OF THE INVENTION

En référence à la figure 1, la pompe à membrane à commande hydraulique selon l'invention est ici une pompe à faible débit et moyenne ou haute pression.With reference to the figure 1 , the hydraulic control diaphragm pump according to the invention is here a pump low flow and medium or high pressure.

La pompe comporte une tête de dosage 1 comprenant une première partie 2 qui définit avec une membrane 3 de la pompe une chambre de pompage 4. La chambre de pompage 4 est reliée à l'extérieur par un canal d'aspiration 5 et un canal de refoulement 6, lesquels sont équipés de clapets unidirectionnels contenus dans des boîtes à clapets.The pump comprises a metering head 1 comprising a first part 2 which defines with a membrane 3 of the pump a pumping chamber 4. The pumping chamber 4 is connected to the outside by a suction channel 5 and a channel 6, which are equipped with unidirectional valves contained in valve boxes.

La membrane 3 est ici une membrane épaisse. La membrane 3 est élastiquement déformable à partir de sa forme au repos (celle représentée) qui correspond à son état en fin de course d'aspiration de la pompe. La raideur de cette membrane 3 est telle que le pouvoir d'aspiration de la pompe est défini par la capacité de la membrane 3 à revenir par elle-même dans sa position de repos. Une telle membrane est bien connue de l'art antérieur, comme par exemple dans la demande FR 2 934 332 de la demanderesse, et ne sera pas davantage détaillée ici.The membrane 3 is here a thick membrane. The membrane 3 is elastically deformable from its rest form (the one shown) which corresponds to its state at the end of the suction stroke of the pump. The stiffness of this membrane 3 is such that the suction power of the pump is defined by the capacity of the membrane 3 to return by itself to its rest position. Such a membrane is well known from the prior art, as for example in the application FR 2 934 332 of the plaintiff, and will not be further detailed here.

La tête de dosage 1 comporte en outre une deuxième partie 7 dans laquelle est ménagée une chambre hydraulique 8. La face de la membrane 3 opposée à celle tournée vers la chambre de pompage 4 est appelée face arrière et est exposée à la pression du fluide hydraulique qui règne dans la chambre hydraulique 8. Des canaux de passage 23 du fluide hydraulique de la chambre hydraulique 8 pour atteindre la face arrière de la membrane 3 sont également ménagés dans la deuxième partie 7.The metering head 1 further comprises a second portion 7 in which a hydraulic chamber 8 is formed. The face of the membrane 3 opposite to that facing the pumping chamber 4 is called the rear face and is exposed to the pressure of the hydraulic fluid. which prevails in the hydraulic chamber 8. Channels for passage 23 of the hydraulic fluid of the hydraulic chamber 8 for reaching the rear face of the membrane 3 are also provided in the second part 7.

La deuxième partie 7 comprend en outre une chemise 9 s'étendant dans la deuxième partie 7 selon un axe horizontal X de sorte qu'une première extrémité 9a de la chemise 9 fasse face à la membrane 3 et qu'une deuxième extrémité 9b de la chemise 9 débouche à l'extérieur de la deuxième partie 7. La chemise 9 comporte un rétrécissement local 10 de sa section externe définissant avec la deuxième partie 7 une chambre de vidange 11.The second portion 7 further comprises a liner 9 extending in the second portion 7 along a horizontal axis X so that a first end 9a of the liner 9 faces the membrane 3 and a second end 9b of the The liner 9 opens out of the second portion 7. The liner 9 has a local constriction 10 of its outer section defining with the second portion 7 a dewatering chamber 11.

La deuxième partie 7 comporte en outre un canal de vidange 12 reliant ladite chambre de vidange 11 à l'extérieur de la pompe. Le canal de vidange 12 s'étend verticalement dans la deuxième partie 7 de la chambre de vidange 11 à l'extrémité inférieure de la deuxième partie 7.The second portion 7 further comprises a drain channel 12 connecting said emptying chamber 11 to the outside of the pump. The drain channel 12 extends vertically in the second part 7 of the emptying chamber 11 at the lower end of the second part 7.

La pompe comporte en outre un piston 13 qui est reçu dans la chemise 9 et qui s'étend selon ledit axe X de sorte qu'une première extrémité 13a du piston débouche dans la chambre hydraulique 8 et qu'une deuxième extrémité 13b du piston 13 débouche hors de la chemise 9.The pump further comprises a piston 13 which is received in the liner 9 and which extends along said axis X so that a first end 13a of the piston opens into the hydraulic chamber 8 and a second end 13b of the piston 13 opens out of the shirt 9.

Le piston 13 est animé mécaniquement par des moyens d'entraînement en translation comprenant un moteur et une transmission, connus en eux-mêmes et qui ne sont pas représentés en intégralité ici, de sorte que le piston 13 puisse effectuer un mouvement de translation dans la chambre hydraulique 8 selon ledit axe X.The piston 13 is mechanically driven by translation drive means comprising a motor and a transmission, known in themselves and which are not represented here in full, so that the piston 13 can perform a translational movement in the hydraulic chamber 8 along said axis X.

Les moyens d'entraînement en translation du piston 13 sont agencés dans un corps de dosage 14 de la pompe. Plus précisément ici le corps de dosage 14 comporte une cavité 15 adjacente à la deuxième partie 7 et dans laquelle la deuxième extrémité 13b du piston 13 est reliée aux moyens d'entraînement en translation, ladite cavité 15 étant à l'air libre. La deuxième partie 7 est ici solidarisée au corps de dosage 14 par l'intermédiaire de la deuxième extrémité 9b de la chemise 9 définissant ainsi la frontière entre la deuxième partie 7 et le corps de dosage 14.The drive means in translation of the piston 13 are arranged in a metering body 14 of the pump. More precisely here the metering body 14 comprises a cavity 15 adjacent to the second part 7 and in which the second end 13b of the piston 13 is connected to the drive means in translation, said cavity 15 being in the open air. The second part 7 is here secured to the metering body 14 via the second end 9b of the liner 9 thus defining the boundary between the second portion 7 and the metering body 14.

Le corps de dosage 14 étant rempli d'air alors que la deuxième partie 7 est remplie d'un fluide hydraulique de commande, il convient d'assurer une étanchéité de la deuxième partie 7. La pompe comporte ainsi un joint d'étanchéité 16 agencé sur le piston 13 au niveau d'une jonction entre la deuxième partie 7 et le corps de dosage 14. A cet effet, un logement est ménagé dans la deuxième extrémité 9b de la chemise 9 et le joint d'étanchéité 16 est agencé à l'intérieur dudit logement. Le joint d'étanchéité 16 est ici un joint à lèvres.The metering body 14 being filled with air while the second part 7 is filled with a hydraulic control fluid, it is necessary to ensure a seal of the second part 7. The pump thus comprises a seal 16 arranged on the piston 13 at a junction between the second portion 7 and the metering body 14. For this purpose, a housing is formed in the second end 9b of the liner 9 and the seal 16 is arranged at the interior of said housing. The seal 16 is here a lip seal.

La pompe comporte ainsi peu de fluide hydraulique de commande. En outre, il est possible de démonter facilement la tête de dosage 1 du reste de la pompe car il n'est pas nécessaire de vidanger la tête de dosage 1 ou le corps de dosage 14 avant.The pump thus has little hydraulic control fluid. In addition, it is possible to easily dismount the metering head 1 from the rest of the pump because it is not necessary to drain the metering head 1 or the metering body 14 before.

La pompe comporte en outre une soupape 17 de régularisation de pression dans la chambre hydraulique 8.The pump further comprises a pressure regulating valve 17 in the hydraulic chamber 8.

La soupape 17 est ici agencée sur la deuxième partie 7 au voisinage d'un point le plus haut de la chambre hydraulique 8 dans la position de travail de la pompe. La soupape 17 s'étend verticalement et comprend une portion inférieure 18 reposant dans un logement 19 ménagé dans la deuxième partie 7 au-dessus de la chemise 9 et une portion supérieure 20 reposant sur la portion inférieure 18 et s'étendant en partie seulement dans ledit logement 19. Une extrémité basse de la portion supérieure 20 comporte ici un filetage interne 21 pour sa fixation à la portion inférieure 18 et un filetage externe 22 pour sa fixation à la deuxième partie 7.The valve 17 is here arranged on the second part 7 in the vicinity of an uppermost point of the hydraulic chamber 8 in the working position of the pump. The valve 17 extends vertically and comprises a lower portion 18 resting in a housing 19 formed in the second portion 7 above the liner 9 and an upper portion 20 resting on the lower portion 18 and extending in part only in said housing 19. A lower end of the upper portion 20 here has an internal thread 21 for attachment to the lower portion 18 and an external thread 22 for attachment to the second portion 7.

La soupape 17 comporte en outre un clapet 24 de décharge qui est taré. Le clapet 24 est ici agencé dans la soupape à la frontière entre la portion inférieure et la portion supérieure. Le clapet 24 délimite ainsi avec la portion supérieure 20 un corps creux 25. Le clapet 24 est configuré de sorte à être passant dans le sens allant de la chambre hydraulique 8 vers le corps creux 25 si la pression dans la chambre hydraulique 8 excède une valeur de seuil réglable par réglage du tarage du clapet 24, par exemple au moyen d'une vis. La soupape 17 comporte en outre un canal principal 26 ménagé dans la portion inférieure 18 pour déboucher sous le clapet 24 et relié à la chambre hydraulique 8 par un conduit 27 ménagé dans la deuxième partie.The valve 17 further comprises a discharge valve 24 which is tared. The valve 24 is here arranged in the valve at the boundary between the lower portion and the upper portion. The valve 24 delimits with the upper portion 20 a hollow body 25. The valve 24 is configured to be passing in the direction from the hydraulic chamber 8 to the hollow body 25 if the pressure in the hydraulic chamber 8 exceeds a threshold value adjustable by setting the calibration of the valve 24, for example by means of a screw. The valve 17 further comprises a main channel 26 formed in the lower portion 18 to open under the valve 24 and connected to the hydraulic chamber 8 by a conduit 27 formed in the second part.

De la sorte, si un blocage se produit dans la chambre de pompage 4, le fluide hydraulique de commande contenu dans la chambre hydraulique 8 peut être évacué de ladite chambre hydraulique 8 via le canal principal 26 puis le clapet 24 de décharge pour déboucher dans le corps creux 25. La soupape 17 permet ainsi de réduire une pression trop importante dans la chambre hydraulique 8.In this way, if a blockage occurs in the pumping chamber 4, the hydraulic control fluid contained in the hydraulic chamber 8 can be discharged from said hydraulic chamber 8 via the main channel 26 and the discharge valve 24 to open into the hollow body 25. The valve 17 thus reduces excessive pressure in the hydraulic chamber 8.

Par ailleurs, le fluide hydraulique de commande contenu dans la chambre hydraulique 8 voit son volume varier notamment lors d'un échappement du fluide de la chambre hydraulique 8 par le clapet 24 ou encore du fait des bulles d'air qui apparaissent au cours des mouvements du piston 13 dans la chambre hydraulique 8 ou encore du fait de la variation du réglable de course de la pompe qui fait varier la course du piston 13 et donc la cylindrée de la pompe. Pour pallier à cet inconvénient, la soupape 17 comporte des moyens de compensation des fuites du fluide hydraulique de commande dans la chambre hydraulique 8.Furthermore, the hydraulic control fluid contained in the hydraulic chamber 8 sees its volume vary especially during an exhaust of the fluid from the hydraulic chamber 8 by the valve 24 or because of the air bubbles that appear during the movements piston 13 in the hydraulic chamber 8 or because of the variation of the adjustable stroke of the pump which varies the stroke of the piston 13 and thus the displacement of the pump. To overcome this drawback, the valve 17 comprises means for compensating the leakage of the hydraulic control fluid in the hydraulic chamber 8.

De façon connue en soi, lesdits moyens comportent un chemin de réalimentation qui relie le corps creux 25 au canal principal 26 en dérivation du clapet 24. A cet effet, le chemin de réalimentation comporte ici un premier canal de réalimentation 28 s'étendant verticalement à travers la portion inférieure 18 entre le corps creux 25 et un volume de réalimentation 29 qui est délimité par l'extrémité basse de la portion inférieure 18 d'une part et le logement 19 correspondant de la deuxième partie 7 d'autre part. Ledit chemin de réalimentation comporte en outre un deuxième canal 30 s'étendant verticalement dudit volume de réalimentation 29 au canal principal 26. Le deuxième canal 30 comporte en outre deux clapets 31 à bille et en série, unidirectionnels, libres, le sens passant de ces deux clapets 31 étant celui allant du corps creux 25 vers la chambre hydraulique 8.In a manner known per se, said means comprise a feedback path which connects the hollow body 25 to the main channel 26 bypassing the valve 24. For this purpose, the feedback path here comprises a first feedback channel 28 extending vertically to through the lower portion 18 between the hollow body 25 and a replenishment volume 29 which is delimited by the low end of the lower portion 18 on the one hand and the corresponding housing 19 of the second part 7 on the other. Said refeeding path further includes a second channel 30 extending vertically from said replenishment volume 29 to the main channel 26. The second channel 30 further comprises two ball valves 31 in series and in series, unidirectional, free, the direction of these two valves 31 being that going from the hollow body 25 to the hydraulic chamber 8.

Une course vers l'arrière du piston 13 permet le retour élastique de la membrane 3 dans sa position de repos. Si cette position est atteinte avant que le piston 13 ait atteint son point mort arrière, il se produit une dépression dans la chambre hydraulique 8 qui se traduit par l'aspiration d'un volume du fluide hydraulique soutiré du corps creux 25 à travers les deux clapets en série 31. La soupape 17 permet ainsi de régulariser également une pression trop faible dans la chambre hydraulique 8.A stroke towards the rear of the piston 13 allows the elastic return of the membrane 3 in its rest position. If this position is reached before the piston 13 has reached its rear dead point, there is a depression in the hydraulic chamber 8 which results in the suction of a volume of the hydraulic fluid withdrawn from the hollow body 25 through the two Valves in series 31. The valve 17 thus makes it possible to regulate also a too low pressure in the hydraulic chamber 8.

La soupape 17 comporte en outre un passage de purge 32 agencé en dérivation du clapet 24 ce qui permet une purge en continue des bulles d'air éventuellement présentes dans la chambre hydraulique 8, l'air passant par le canal de principal 26 et ledit passage de purge 32 pour aboutir au corps creux. Une partie des bulles d'air est ainsi évacuée par le canal principal 26.The valve 17 further comprises a purge passage 32 arranged in a bypass of the valve 24 which allows a continuous purge of the air bubbles possibly present in the hydraulic chamber 8, the air passing through the main channel 26 and said passage purge 32 to result in the hollow body. Part of the air bubbles is thus evacuated via the main channel 26.

Le canal principal 26 est agencé au-dessus de la chambre hydraulique 8 de manière à profiter de l'accumulation naturelle de l'air au point haut de ladite chambre hydraulique 8 pour faciliter la purge des bulles d'air contenues dans la chambre hydraulique 8 dans la soupape 17.The main channel 26 is arranged above the hydraulic chamber 8 so as to take advantage of the natural accumulation of air at the high point of said hydraulic chamber 8 to facilitate the purge of the air bubbles contained in the hydraulic chamber 8 in the valve 17.

La pompe comporte en outre des moyens de dégazage dédiés du fluide hydraulique de commande. Les moyens de dégazage dédiés comportent un chemin de dégazage s'étendant dans la deuxième partie 7.The pump further comprises degassing means dedicated to the hydraulic control fluid. The dedicated degassing means comprise a degassing path extending into the second part 7.

Le chemin de dégazage comporte ici un premier canal 33 s'étendant transversalement dans la chemise 9 de sorte à déboucher à son extrémité basse au niveau d'une zone de jonction entre le piston et le joint et à déboucher à son extrémité haute dans la chambre de vidange 11. Le premier canal 33 est donc agencé au plus près de la zone d'entrée de l'air provenant du corps de dosage 14 afin de prélever ledit air. Le premier canal 33 s'étend donc ici en direction de la soupape 17 et transversalement à l'axe X.The degassing path here comprises a first channel 33 extending transversely in the jacket 9 so as to open at its lower end at a junction zone between the piston and the seal and to open at its upper end in the chamber 11. The first channel 33 is thus arranged closer to the air inlet zone from the metering body 14 to collect said air. The first channel 33 thus extends here in the direction of the valve 17 and transversely to the axis X.

Le chemin de dégazage comporte un deuxième canal 34 s'étendant transversalement dans la deuxième partie 7 de sorte à déboucher à son extrémité basse dans la chambre de vidange 11 et à son extrémité haute à l'air libre ce qui facilite son usinage. L'extrémité haute du deuxième canal 34 est cependant obturée par un bouchon 35. Le deuxième canal 34 est agencé de sorte à déboucher à son extrémité basse dans la chambre de vidange 11 en partie supérieure de la chambre de vidange 11 sensiblement au même niveau que l'extrémité haute du premier canal 33. Le premier canal 33 et le deuxième canal 34 sont ainsi reliés par l'intermédiaire de la chambre de vidange 11. De préférence, le deuxième canal 34 est agencé de sorte que son extrémité basse débouche au-dessus de l'extrémité haute du premier canal 33 ce qui assure une meilleure liaison entre les deux canaux et ainsi un dégazage plus efficace. Le deuxième canal 34 s'étend donc ici en direction opposée de la soupape 17 transversalement à l'axe X.The degassing path comprises a second channel 34 extending transversely in the second portion 7 so as to open at its lower end in the emptying chamber 11 and at its upper end in the open air which facilitates its machining. The upper end of the second channel 34 is however closed by a plug 35. The second channel 34 is arranged so as to open at its lower end in the emptying chamber 11 in the upper part of the emptying chamber 11 substantially at the same level as the upper end of the first channel 33. The first channel 33 and the second channel 34 are thus connected via the emptying chamber 11. Preferably, the second channel 34 is arranged so that its lower end opens out. above the high end of the first channel 33 which ensures a better connection between the two channels and thus a more effective degassing. The second channel 34 thus extends here in the opposite direction of the valve 17 transversely to the axis X.

Le chemin de dégazage comporte en outre un troisième canal 36 s'étendant transversalement dans la deuxième partie 7 de sorte à déboucher à son extrémité basse dans le deuxième canal 34 au niveau de l'extrémité haute dudit deuxième canal 34 et à son extrémité haute dans le logement 19 recevant la soupape 17. Le troisième canal 36 s'étend donc ici en direction de la soupape 17 et transversalement à l'axe X.The degassing path further comprises a third channel 36 extending transversely in the second portion 7 so as to open at its lower end in the second channel 34 at the upper end of said second channel 34 and at its upper end in the housing 19 receiving the valve 17. The third channel 36 extends here in the direction of the valve 17 and transversely to the axis X.

Le chemin de dégazage comporte en outre un quatrième canal 37 s'étendant à travers l'une des parois de la portion supérieure 20 de la soupape de sorte à être connecté à une première extrémité à l'extrémité haute du troisième canal 36 et à déboucher à sa deuxième extrémité dans le corps creux 25. Le quatrième canal 37 s'étend ici sensiblement horizontalement.The degassing path further comprises a fourth channel 37 extending through one of the walls of the upper portion 20 of the valve so as to be connected at a first end to the upper end of the third channel 36 and to open at its second end in the hollow body 25. The fourth channel 37 extends here substantially horizontally.

Ainsi, l'extrémité basse du premier canal 33 forme la première extrémité du chemin de dégazage et est située au point le plus bas dudit chemin alors que la deuxième extrémité du quatrième canal 37 forme la deuxième extrémité du chemin de dégazage et est située au point le plus haut dudit chemin.Thus, the lower end of the first channel 33 forms the first end of the degassing path and is located at the lowest point of said path while the second end of the fourth channel 37 forms the second end of the degassing path and is located at the the highest of the said path.

Lors du fonctionnement de la pompe, l'air provenant du corps de dosage 14 est purgé en continu par le chemin de dégazage, l'air passant successivement par le premier canal 33, le deuxième canal 34, le troisième canal 36 et le quatrième canal 37 pour déboucher dans le corps creux 25. En outre, le chemin de dégazage prélève l'air directement au niveau du joint d'étanchéité 16 de sorte que pas ou peu d'air provenant du corps de dosage 14 atteigne la chambre hydraulique 8. Ceci évite de dégrader les performances de la pompe. Par ailleurs, le chemin de dégazage débouchant dans la portion supérieure 20 de la soupape 17, pas ou peu d'air se trouve présent dans le chemin de réalimentation ce qui assure qu'aucune bulle ou presque ne soit envoyée dans la chambre hydraulique 8 lors d'une phase de compensation des fuites du fluide hydraulique dans la chambre hydraulique 8. Les moyens de dégazage dédiés permettent ainsi un dégazage très efficace et continu de l'air présent dans le fluide hydraulique.During the operation of the pump, the air coming from the metering body 14 is purged continuously by the degassing path, the air successively passing through the first channel 33, the second channel 34, the third channel 36 and the fourth channel 37 In addition, the degassing path removes the air directly at the seal 16 so that little or no air from the metering body 14 reaches the hydraulic chamber 8. This avoids degrading the performance of the pump. Moreover, the degassing path opening into the upper portion 20 of the valve 17, little or no air is present in the feed path which ensures that no bubble or almost is sent into the hydraulic chamber 8 when a phase of compensation of leakage of the hydraulic fluid in the hydraulic chamber 8. The dedicated degassing means thus allow a very effective and continuous degassing of the air present in the hydraulic fluid.

Le chemin de dégazage est ici conformé de sorte à acheminer l'air dans la soupape 17 en débouchant dans la soupape 17 sensiblement au-dessus du clapet 24.The degassing path is here shaped so as to convey the air into the valve 17 by opening into the valve 17 substantially above the valve 24.

De la sorte, quand bien même la course du piston 13 serait modifiée, le dégazage serait toujours efficace.In this way, even if the stroke of the piston 13 would be modified, degassing would still be effective.

Typiquement, le chemin de dégazage est conformé de sorte que le volume de fluide hydraulique compris entre le quatrième canal 37 (débouchant dans la soupape 17) et le volume de réalimentation 29 soit supérieur à une cylindrée maximale de la pompe.Typically, the degassing path is shaped so that the volume of hydraulic fluid between the fourth channel 37 (opening into the valve 17) and the replenishment volume 29 is greater than a maximum displacement of the pump.

De préférence, les différents canaux du chemin de dégazage ont une section plus importante que les canaux reliant la chambre hydraulique 8 à la soupape 17 et que le canal principal 26. La section desdits canaux du chemin de dégazage permet d'éviter que des bulles ne demeurent coincées à l'intérieur dudit chemin de dégazage, les bulles à évacuer étant plus nombreuses dans le chemin de dégazage.Preferably, the different channels of the degassing path have a larger section than the channels connecting the hydraulic chamber 8 to the valve 17 and the main channel 26. The section of said channels degassing path can prevent bubbles from remain trapped inside said degassing path, the bubbles to be evacuated being more numerous in the degassing path.

Ici, le deuxième canal 34 du chemin de dégazage a en outre une section plus importante que le premier canal 33, le troisième canal 36 et le quatrième canal 37 du chemin de dégazage. Le deuxième canal 34 du chemin de dégazage a typiquement une section 2 à 4 fois plus importante que celle du premier canal 33 du chemin de dégazage. Ceci permet d'évacuer efficacement les bulles du premier canal 33 au troisième canal 36.Here, the second channel 34 of the degassing path further has a larger section than the first channel 33, the third channel 36 and the fourth channel 37 of the degassing path. The second channel 34 of the degassing path typically has a section 2 to 4 times larger than that of the first channel 33 of the degassing path. This effectively discharges the bubbles from the first channel 33 to the third channel 36.

La pompe selon l'invention ainsi conformée, le fluide hydraulique de commande est présent uniquement dans la deuxième partie 7. Le fluide est ainsi présent et sous pression dans la chambre hydraulique 8, les canaux de passage 23, le conduit 27 reliant la chambre hydraulique 8 à la soupape 17 et le canal principal 26. Le fluide est également présent à pression inférieure ou égale à la pression atmosphérique dans le reste de la soupape 17 (corps creux 25 et chemin de réalimentation), dans le chemin de dégazage, dans la chambre de vidange 11 et dans le canal de vidange 12.The pump according to the invention thus shaped, the hydraulic control fluid is present only in the second part 7. The fluid is thus present and under pressure in the hydraulic chamber 8, the passage channels 23, the conduit 27 connecting the hydraulic chamber 8 to the valve 17 and the main channel 26. The fluid is also present at a pressure less than or equal to the atmospheric pressure in the remainder of the valve 17 (hollow body 25 and feed path), in the degassing path, in the drain chamber 11 and in the drain channel 12.

L'air à dégazer se trouve très majoritairement à la jonction entre la deuxième partie 7 et le corps de dosage 14 et est évacué par le chemin de dégazage et se trouve minoritairement (voire même est inexistant) dans la chambre hydraulique 8 et est évacué préférentiellement par la soupape 17 et notamment le canal principal 26 et le passage de purge 32.Most of the air to be degassed is at the junction between the second part 7 and the metering body. 14 and is evacuated by the degassing path and is in a minority (or even nonexistent) in the hydraulic chamber 8 and is preferably evacuated by the valve 17 and in particular the main channel 26 and the purge passage 32.

La pompe selon l'invention permet donc un dégazage efficace et continu de l'air présent dans le fluide hydraulique et évite la présence d'une trop grande quantité de bulles d'air dans la chambre hydraulique 8. Le débit de la pompe selon l'invention s'avère ainsi régulier, précis et stable.The pump according to the invention thus allows an effective and continuous degassing of the air present in the hydraulic fluid and avoids the presence of too much air bubbles in the hydraulic chamber 8. The flow rate of the pump according to the invention the invention thus proves to be regular, precise and stable.

Bien entendu l'invention n'est pas limitée aux modes de réalisation décrits et on peut y apporter des variantes de réalisation sans sortir du cadre de l'invention tel que défini par les revendications.Naturally, the invention is not limited to the embodiments described and variant embodiments can be made without departing from the scope of the invention as defined by the claims.

En particulier, la pompe pourra avoir une autre forme que celle décrite. Ainsi, en référence à la figure 2, dans une variante de l'invention (les éléments en commun avec le mode de réalisation décrit précédemment conservent la même numérotation augmentée d'une centaine) un canal de connexion 140 de la chambre de vidange 111 au chemin de réalimentation est ménagé dans la deuxième partie 107. Typiquement, ledit canal de connexion 140 débouche en partie basse du chemin de réalimentation ici dans le volume de réalimentation 129. Ceci ne nuit pas outre mesure au bon dégazage par le chemin de dégazage du fait de l'agencement optimisé entre le premier canal 133 et le deuxième canal 134 dudit chemin de dégazage qui assure que les bulles d'air remontent préférentiellement par le deuxième canal 134 plutôt que par le canal de connexion 140.In particular, the pump may have another shape than that described. So, with reference to the figure 2 in a variant of the invention (the elements in common with the embodiment described above retain the same numbering increased by a hundred) a connection channel 140 of the emptying chamber 111 to the feed path is formed in the second Part 107. Typically, said connection channel 140 opens at the bottom of the feed path here in the feed volume 129. This does not unduly affect the good degassing by the degassing path because of the optimized arrangement between the first channel 133 and the second channel 134 of said degassing path which ensures that the air bubbles rise preferentially through the second channel 134 rather than by the connection channel 140.

Le chemin de dégazage pourra également avoir une toute autre forme que celle indiquée : ledit chemin pourra ainsi comporter un nombre différent de canaux et lesdits canaux pourront être orientés différemment. Par exemple le deuxième canal pourra s'étendre verticalement ou s'étendre transversalement en direction de la soupape. Le premier canal et le deuxième canal pourront être connectés l'un à l'autre sans l'intermédiaire de la chambre de vidange. Les moyens de dégazage dédiés pourront comporter plusieurs chemins de dégazage.The degassing path may also have any other shape than indicated: said path may thus comprise a different number of channels and said channels may be oriented differently. For example the second channel may extend vertically or extend transversely towards the valve. The first channel and the second channel can be connected to each other without the intermediary of the emptying chamber. The dedicated degassing means may include several degassing paths.

Par ailleurs, la soupape pourra avoir une toute autre forme que celle indiquée. La soupape pourra ainsi être une soupape telle que décrite dans la demande EP 2 394 056 de la présente demanderesse.In addition, the valve may have any other shape than that indicated. The valve may thus be a valve as described in the application EP 2 394 056 of the present applicant.

La membrane pourra être différente de ce qui a été décrite. La membrane pourra ainsi être une membrane composite comprenant une paroi interne épaisse entourée de deux parois métalliques minces telle que décrite dans les demandes FR 2 670 537 et FR 2 934 332 de la demanderesse.The membrane may be different from what has been described. The membrane may thus be a composite membrane comprising a thick inner wall surrounded by two thin metal walls as described in the applications FR 2,670,537 and FR 2 934 332 of the plaintiff.

La pompe pourra en outre comporter un dispositif de détection de rupture de la membrane.The pump may further comprise a device for detecting rupture of the membrane.

La soupape pourra comporter tout autre dispositif de dégazage du fluide hydraulique de commande connu que le passage de purge décrit.The valve may comprise any other known control hydraulic fluid degassing device than the purge passage described.

Claims (9)

Pompe à membrane à commande hydraulique, comportant : - une tête de dosage (1 ; 101) comprenant une première partie (2 ; 102) ayant une chambre de pompage (3 ; 103) et une deuxième partie (7 ; 107) dans laquelle est ménagée une chambre hydraulique (8 ; 108) qui est remplie d'un fluide hydraulique de commande et qui est séparée de la chambre de pompage par une membrane (3 ; 103), - un corps de dosage (14 ; 114) comprenant des moyens d'entraînement en translation d'un piston (13 ; 113) de la pompe dans la chambre hydraulique selon un axe de translation (X), - au moins un joint d'étanchéité (16 ; 116) agencé sur le piston au niveau d'une jonction entre la deuxième partie et le corps de dosage, - une soupape (17 ; 117) de régularisation de pression au voisinage d'un point le plus haut de la chambre hydraulique dans la position de travail de la pompe, la soupape ayant un corps creux (25 ; 125) en communication avec la chambre hydraulique via un clapet (24 ; 124) qui est passant dans le sens de la chambre hydraulique vers le corps creux, - des moyens de dégazage dédiés du fluide, lesdits moyens comprenant au moins un chemin de dégazage (33, 34, 36, 37 ; 133, 134, 136, 137) s'étendant dans la deuxième partie non parallèlement à l'axe de translation de sorte qu'une première extrémité du chemin formant le point le plus bas dudit chemin débouche au niveau d'une jonction entre le piston et le joint et qu'une deuxième extrémité du chemin formant le point le plus haut dudit chemin débouche dans le corps de soupape au-dessus du clapet. Hydraulically operated diaphragm pump, comprising: a metering head (1; 101) comprising a first portion (2; 102) having a pumping chamber (3; 103) and a second portion (7; 107) in which a hydraulic chamber (8; 108) is formed; which is filled with a hydraulic control fluid and which is separated from the pumping chamber by a membrane (3; 103), a metering body (14; 114) comprising means for translational movement of a piston (13; 113) of the pump in the hydraulic chamber along a translation axis (X); at least one seal (16; 116) arranged on the piston at a junction between the second part and the metering body; a pressure regulating valve (17; 117) in the vicinity of an uppermost point of the hydraulic chamber in the working position of the pump, the valve having a hollow body (25; 125) in communication with the chamber; hydraulic via a valve (24; 124) which is passing in the direction of the hydraulic chamber towards the hollow body, dedicated degassing means for the fluid, said means comprising at least one degassing path (33, 34, 36, 37, 133, 134, 136, 137) extending in the second part not parallel to the translation axis; so that a first end of the path forming the lowest point of said path opens at a junction between the piston and the seal and a second end of the path forming the highest point of said path opens into the body Valve above the valve. Pompe selon la revendication 1, dans laquelle le chemin de dégazage comporte plusieurs canaux (33, 34, 36, 37 ; 133, 134, 136, 137).Pump according to claim 1, wherein the degassing path comprises a plurality of channels (33, 34, 36, 37, 133, 134, 136, 137). Pompe selon la revendication 2, dans laquelle le chemin de dégazage comporte : - un premier canal (33 ; 133) dont une des extrémités forme la première extrémité du chemin de dégazage, le premier canal s'étendant transversalement par rapport à l'axe de translation, - un deuxième canal (34 ; 134) qui est relié au premier canal et qui s'étend transversalement à l'axe de translation, - un troisième canal (36 ; 136) qui est connecté au deuxième canal et qui s'étend transversalement par rapport à l'axe de translation, - un quatrième canal (37 ; 137) ayant une extrémité connectée au troisième canal et une extrémité définissant la deuxième extrémité du chemin de dégazage. Pump according to claim 2, wherein the degassing path comprises: a first channel (33; 133), one end of which forms the first end of the degassing path, the first channel extending transversely with respect to the translation axis; a second channel (34; 134) which is connected to the first channel and which extends transversely to the translation axis, a third channel (36; 136) which is connected to the second channel and which extends transversely with respect to the translation axis, a fourth channel (37; 137) having an end connected to the third channel and an end defining the second end of the degassing path. Pompe selon la revendication 3, dans laquelle une extrémité basse du deuxième canal (34 ; 134) et l'autre des extrémités du premier canal (33 ; 133) débouchent dans une chambre de vidange (11 ; 111) de la deuxième partie (7 ; 107).A pump according to claim 3, wherein a lower end of the second channel (34; 134) and the other end of the first channel (33; 133) open into a discharge chamber (11; 111) of the second portion (7; 107). Pompe selon la revendication 4, dans laquelle l'extrémité basse du deuxième canal (34 ; 134) débouche dans la chambre de vidange (11 ; 111) en partie supérieure de ladite chambre de vidange sensiblement au même niveau que l'autre extrémité du premier canal (33 ; 133).Pump according to claim 4, in which the lower end of the second channel (34; 134) opens into the emptying chamber (11; 111) in the upper part of said emptying chamber substantially at the same level as the other end of the first channel (33; 133). Pompe selon la revendication 5, dans laquelle l'extrémité basse du deuxième canal (34 ; 134) débouche au-dessus de l'autre extrémité du premier canal (33 ; 133).The pump of claim 5 wherein the lower end of the second channel (34; 134) opens above the other end of the first channel (33; 133). Pompe selon la revendication 3, dans laquelle le deuxième canal (34 ; 134) s'étend en direction opposée de la soupape (17 ; 117) et le premier canal (33 ; 133) et le troisième canal (36 ; 136) s'étendent en direction de la soupape de régularisation.The pump of claim 3 wherein the second channel (34; 134) extends in the opposite direction of the valve (17; 117) and the first channel (33; 133) and the third channel (36; 136) extend towards the regulating valve. Pompe selon la revendication 3, dans laquelle le deuxième canal (34 ; 134) a une section plus importante que le premier canal (33 ; 133), le troisième canal (36 ; 136) et le quatrième canal (37 ; 137).The pump of claim 3, wherein the second channel (34; 134) has a larger section than the first channel (33; 133), the third channel (36; 136) and the fourth channel (37; 137). Pompe selon la revendication 1, dans laquelle le chemin de dégazage a une section globale plus importante que celle des canaux reliant la chambre hydraulique (8 ; 108) à la soupape (17 ; 117).The pump of claim 1, wherein the degassing path has a larger overall cross section than the channels connecting the hydraulic chamber (8; 108) to the valve (17; 117).
EP15168751.4A 2014-05-27 2015-05-21 Diaphragm pump with hydraulic control including a dedicated degassing path Withdrawn EP2949936A1 (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
FR1454797A FR3021713B1 (en) 2014-05-27 2014-05-27 HYDRAULICALLY CONTROLLED MEMBRANE PUMP COMPRISING A DEDICATED DEGASSAGE PATH

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EP2949936A1 true EP2949936A1 (en) 2015-12-02

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US (1) US9856870B2 (en)
EP (1) EP2949936A1 (en)
JP (1) JP6290825B2 (en)
CN (1) CN105134564B (en)
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Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US11149723B2 (en) * 2019-12-31 2021-10-19 Psg California Llc Diaphragm pump leak detection

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0283026A2 (en) * 1987-03-18 1988-09-21 LEWA Herbert Ott GmbH + Co. Method and device for starting an hydraulic membrane pump against a load
FR2670537A1 (en) 1990-12-18 1992-06-19 Milton Roy Dosapro HYDRAULICALLY CONTROLLED MEMBRANE PUMP FOR HIGH PRESSURES.
FR2934332A1 (en) 2008-07-28 2010-01-29 Milton Roy Europe Fluid metering pump, has membrane mounted between cylindrical body and pump head, and comprising cylindrical peripheral rim for directly locking membrane between body and head, where concavity of membrane is turned towards pumping chamber
WO2010098707A1 (en) * 2009-02-24 2010-09-02 Tetra Laval Holdings & Finance S.A. A membrane pump head for a homogenizer or a high-pressure pump
CN101037992B (en) * 2007-03-29 2010-10-06 合肥华升泵阀有限责任公司 Fine vacuum diaphragm pump
EP2394056A1 (en) 2009-02-03 2011-12-14 Milton Roy Europe Pump with an elastic membrane and hydraulic control

Family Cites Families (15)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
SU659786A1 (en) * 1978-02-17 1979-04-30 Особое Конструкторское Бюро По Конструированию,Исследованию И Внедрению Глубинных Бесштанговых Насосов Submersible diaphragm electric pump
DE3446952A1 (en) * 1984-12-21 1986-07-10 Lewa Herbert Ott Gmbh + Co, 7250 Leonberg DIAPHRAGM PUMP WITH ROTATING
DE4241030C1 (en) * 1992-12-05 1994-06-01 Lang Apparatebau Gmbh Dosing pump with vent valve
US6086340A (en) * 1999-05-11 2000-07-11 Milton Roy Company Metering diaphragm pump having a front removable hydraulic refill valve
RU16527U1 (en) * 2000-07-21 2001-01-10 Агапов Валерий Ибрагимович MEMBRANE HYDRAULIC DRIVE DOSING PUMP
US7175397B2 (en) * 2002-09-27 2007-02-13 Pulsafeeder, Inc. Effervescent gas bleeder apparatus
RU31153U1 (en) * 2003-04-18 2003-07-20 Подрезов Александр Владимирович Diaphragm hydraulic metering pump
RU38854U1 (en) * 2004-02-26 2004-07-10 Подрезов Александр Владимирович MEMBRANE HYDRAULIC DRIVE DOSING PUMP
US7665974B2 (en) * 2007-05-02 2010-02-23 Wanner Engineering, Inc. Diaphragm pump position control with offset valve axis
CN201884234U (en) * 2010-07-28 2011-06-29 德帕姆(杭州)泵业科技有限公司 Pump head of diaphragm type metering pump
CN201972872U (en) * 2010-12-29 2011-09-14 大庆德美特尔泵业制造有限公司 Large discharge diaphragm metering pump with oil filling limit and automatic deflation system
CA2824025A1 (en) 2011-01-31 2012-08-09 Laitram, L.L.C. Grader
CN202023725U (en) * 2011-04-08 2011-11-02 南方泵业股份有限公司 Automatic oil supply control system of diaphragm type metering pump
CN202659465U (en) * 2012-06-02 2013-01-09 范学齐 Flow-adjustable hydraulic diaphragm metering pump
US20140180125A1 (en) 2012-12-21 2014-06-26 Volcano Corporation Rotational imaging apparatus

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0283026A2 (en) * 1987-03-18 1988-09-21 LEWA Herbert Ott GmbH + Co. Method and device for starting an hydraulic membrane pump against a load
FR2670537A1 (en) 1990-12-18 1992-06-19 Milton Roy Dosapro HYDRAULICALLY CONTROLLED MEMBRANE PUMP FOR HIGH PRESSURES.
CN101037992B (en) * 2007-03-29 2010-10-06 合肥华升泵阀有限责任公司 Fine vacuum diaphragm pump
FR2934332A1 (en) 2008-07-28 2010-01-29 Milton Roy Europe Fluid metering pump, has membrane mounted between cylindrical body and pump head, and comprising cylindrical peripheral rim for directly locking membrane between body and head, where concavity of membrane is turned towards pumping chamber
EP2394056A1 (en) 2009-02-03 2011-12-14 Milton Roy Europe Pump with an elastic membrane and hydraulic control
WO2010098707A1 (en) * 2009-02-24 2010-09-02 Tetra Laval Holdings & Finance S.A. A membrane pump head for a homogenizer or a high-pressure pump

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CN105134564A (en) 2015-12-09
JP6290825B2 (en) 2018-03-07
FR3021713B1 (en) 2019-04-05
US20150345488A1 (en) 2015-12-03
RU2598499C1 (en) 2016-09-27
JP2015224643A (en) 2015-12-14
CN105134564B (en) 2018-02-09
US9856870B2 (en) 2018-01-02
FR3021713A1 (en) 2015-12-04

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