EP3025058B1 - Rotary-oscillating subassembly and rotary-oscillating volumetric pumping device for volumetrically pumping a fluid - Google Patents

Description

Technical area

The invention generally relates to an oscillating-rotational subassembly and an oscillating-rotary pumping device for volumetric pumping of a fluid.

Prior art

The use of volumetric pumping devices for production and / or reconstitution (liquid-solid or liquid-liquid mixtures) and / or administration (injection, infusion, oral, spray, etc.) is known, in particular for medical, aesthetic, veterinary applications, For this type of application, precise quantities of fluid, for example to a container, or to be administered directly to a patient via an injection device, must be pumped in a controlled manner, infusion or other suitable device.

In particular in the medical field, in a hospital context, in a care center or at home, it is known to use devices such as "push syringe", "cartridge shoots" and peristaltic pumps.

The devices of the "push syringe" type require the pre-filling of the syringe. This filling is, most of the time done manually, which represents a laborious operation to achieve, especially since this filling requires the respect of specific precautions to ensure the integrity of the liquid and the safety of the personnel.

Cartridge type devices require the use of silicone to lubricate the cartridge body and thereby facilitate sliding between the generally elastomeric piston and the cartridge body generally made of glass or plastic. The presence of silicone in direct contact with the fluid generates problems of stability of the molecules during storage in the cartridge before use.

Peristaltic pumps are bulky and bulky. Moreover, the operating principle of these peristaltic pumps requires them to have a flexible hose that prevents reaching high pressures. Due to the flexibility of the pipe, the volumetric efficiency (actual flow / demand flow) changes significantly with the pressure variations of the output fluid and quickly degrades the dosing accuracy without the help of auxiliary sensor (eg a flow sensor ). Thus, the operating pressures of such peristaltic pumps are typically less than 5 bar which limits their implementation with viscous liquids. In addition, it is common that this type of pump generates tiny air bubbles in the fluid, which can have an unacceptable effect. Finally, the rapid aging of the mechanical properties of the pipe poses problems of modifying the performances and / or the reliability over time of this type of pump. The same type of disadvantages are encountered with diaphragm pumps.

It is also possible to use flap pumps. However, the passage of the fluid is then free between the inlet and outlet ducts in the case where the inlet is in overpressure with respect to the outlet. Also, the valve pumps do not offer the possibility of having a neutral position in which any circulation of the fluid is prevented. Finally they are not reversible.

It is also possible to use gear or lobe pumps. However, this type of pump has a low self-priming capacity and a large internal volume of retained fluid which makes them difficult to use for such medical, aesthetic or veterinary applications.

The publications GB 122 629 , DE 36 30 528 and US 3,168,872 disclose an oscillating-rotational volumetric pumping device comprising a hollow body defining a cavity and the wall of which is traversed by two ducts opening into the cavity, a piston housed in the cavity in which it is angularly displaceable and in alternating axial translation to vary the volume of the working chamber that it defines with the cavity. US 3,168,872 describes in particular that the piston comprises a flat able to be successively in communication with one of the ducts during an intake phase, then none of the ducts during a switching phase, then the other of the ducts during a discharge phase, then again none of the conduits during a new switching phase, and so on. Thus, the fluid can be sucked by one of the conduits during the intake phase, stored in the working chamber during the switching phase, and then discharged by the other conduit during the discharge phase. However, the proper operation of this rotary tilt-rotary pumping device imposes a good seal between the piston and the cavity, which requires severe manufacturing tolerances, difficult to meet without significant additional cost of production and / or significant friction penalizing the energy efficiency of the rotary tilt-rotary pumping device.

Presentation of the invention

The object of the invention is to overcome these drawbacks by proposing an oscillation-rotary subassembly for volumetric pumping and a volumetric oscillation-rotary pumping device of a moderate manufacturing cost with a limited number of parts, reversible, precise , allowing the transfer of viscous liquid even at high pressure, and having a good fluid and energy efficiency.

• une première ligne d'étanchéité bordant angulairement ladite rainure, lesdites premières lignes d'étanchéité étant séparées entre elles d'un angle passant par ladite rainure, supérieur à chacun des angles séparant les bords d'un même conduit, et inférieur à chacun des angles séparant les bords adjacents d'un conduit et de l'autre conduit,
• et une seconde ligne d'étanchéité, chaque seconde ligne d'étanchéité étant séparée d'une desdites premières lignes d'étanchéité d'un angle ne passant pas par ladite rainure, inférieur à chaque angle séparant le bord d'un conduit et le bord adjacent de l'autre conduit, et supérieur à chaque angle séparant les bords opposés d'un même conduit,

et en ce que l'angle séparant chaque première ligne d'étanchéité d'au moins une des secondes lignes d'étanchéité en passant par ladite rainure est supérieur à l'angle séparant les bords axialement opposés des conduits.For this purpose, the subject of the invention is an oscillating-rotary subassembly for volumetric pumping of a fluid, comprising a hollow body defining a cylindrical cavity of longitudinal axis and having a wall which is traversed by at least two ducts opening radially in said cavity, a piston housed in said cavity with which it defines a working chamber and having, on its cylindrical surface, a kind of longitudinal groove or recess opening longitudinally in said working chamber, said piston being provided with a seal sealing material made of a material having a modulus of elasticity lower than that of said piston and said body and carried by said piston, running along said groove to ensure the fluidic seal between said piston and said cavity, being angularly movable to put said working chamber in fluid communication with at least one, then none, then at least the other of said conduits, and alternately in longitudinal translation so as to vary the volume of said working chamber and successively suck and then discharge said fluid by one then the other of said conduits, characterized in that the piston has a first axial end opposite a second axial end, said second axial end being in contact with the working chamber,
said seal is in a plurality of parts including a first torus-shaped sealing portion which extends around the cylindrical surface of the piston on the side of its first axial end, a second half-shaped sealing portion; torus which extends around the cylindrical surface of the piston on the side of its second axial end, the half-torus having two ends spaced apart from one another on the cylindrical periphery of the piston, and a third sealing part formed by two sealing tongues which respectively extend axially on the outer surface of the piston between a first end of the half-torus and the torus and a second end of the half-torus and the torus,
in that the two tabs are angularly distinct from one another and each define:

• a first sealing line angularly bordering said groove, said first sealing lines being separated from each other by an angle passing through said groove, greater than each of the angles separating the edges of the same conduit, and less than each of the angles separating the adjacent edges of one conduit and the other conduit,
• and a second sealing line, each second sealing line being separated from one of said first sealing lines by an angle not passing through said groove, less than each angle between the edge of a conduit and the edge adjacent to the other duct, and greater than each angle separating the opposite edges of the same duct,

and in that the angle between each first sealing line of at least one of the second sealing lines passing through said groove is greater than the angle between the axially opposite edges of the ducts.

The idea underlying the invention is to provide a seal between the piston and the body, this seal having a particular shape to ensure effective sealing while limiting friction to improve energy efficiency. and increase the flow accuracy of the tilt and turn subassembly.

• le piston comporte une gorge périphérique recevant le joint d'étanchéité, formée au moins d'une gorge annulaire recevant le tore d'étanchéité, d'une gorge demi-annulaire recevant le demi-tore d'étanchéité, et d'une gorge longitudinale reliant entre elles la gorge annulaire et la gorge demi-annulaire et recevant la languette d'étanchéité ;
• l'un au moins desdits tore d'étanchéité et gorge annulaire est prévu longitudinalement au-delà de ladite rainure par rapport à ladite chambre de travail et au-delà desdits conduits par rapport à ladite chambre de travail, en ce que l'un au moins desdites demi-tore d'étanchéité et gorge demi-annulaire est prévu longitudinalement au niveau de ladite extrémité de ladite rainure débouchant dans ladite chambre de travail et entre lesdits conduits et ladite chambre de travail ;
• le piston comporte, sur sa périphérie, au moins une zone évidée fermée entourée de toute part par ledit joint d'étanchéité, ladite zone évidée étant prévue angulairement de sorte à être en regard d'un conduit lorsque ladite rainure est en regard d'un autre conduit, ladite gorge longitudinale étant formée de deux bras prévus chacun entre ladite rainure et ladite zone évidée, en ce que chaque bras reçoit l'une desdites languettes d'étanchéité de sorte à isoler fluidiquement ladite zone évidée de ladite rainure en toute position longitudinale et angulaire dudit piston dans ledit corps ;
• la zone évidée s'étend sur un angle inférieur à chaque angle séparant les bords adjacents d'un conduit et de l'autre conduit ;
• le piston comporte au moins un plot d'équilibrage prévu dans ladite rainure et s'étendant radialement de sorte que son sommet soit en appui contre ladite cavité tout en autorisant le passage fluidique sur ses cotés ;
• il comporte au moins un premier et un second étage à chacun desquels correspond de manière distincte un ensemble de deux conduits, une chambre de travail, une rainure et un joint d'étanchéité.
• il comporte au moins une came et un doigt de guidage, portés l'un par ledit piston, l'autre par ledit corps, et agencés pour coopérer réciproquement de sorte que la rotation dudit piston par rapport audit corps provoque :
  • sur une première portion angulaire, la translation axiale dans un premier sens dudit piston par rapport audit corps,
  • sur une seconde portion angulaire, l'immobilisation axiale dudit piston par rapport audit corps,
  • sur une troisième portion angulaire, la translation axiale dans un second sens dudit piston par rapport audit corps,
  • sur une quatrième portion angulaire, l'immobilisation axiale dudit piston par rapport audit corps,
  • lesdits conduits, ledit joint d'étanchéité et ladite rainure étant agencés pour que lesdits conduits soient obturés pendant lesdites seconde et quatrième portions angulaires.

The oscillating-rotary subassembly according to the invention may advantageously have the following particularities:

• the piston comprises a peripheral groove receiving the seal, formed at least of an annular groove receiving the sealing torus, a semi-annular groove receiving the half-torus seal, and a longitudinal groove interconnecting the annular groove and the semi-annular groove and receiving the sealing tongue;
• at least one of said sealing torus and annular groove is provided longitudinally beyond said groove with respect to said working chamber and beyond said ducts with respect to said working chamber, in that one at least one of said half-torus and half-annular groove is provided longitudinally at said end of said groove opening into said working chamber and between said ducts and said working chamber;
• the piston comprises, on its periphery, at least one closed recessed area surrounded on all sides by said seal, said recessed area being angularly provided so as to be opposite a conduit when said groove is opposite a another conduit, said longitudinal groove being formed of two arms each provided between said groove and said recessed area, in that each arm receives one of said sealing tongues so as to fluidly isolate said recessed area of said groove in any longitudinal and angular position of said piston in said body;
• the recessed area extends at an angle less than each angle separating the adjacent edges of one duct and the other duct;
• the piston comprises at least one balancing pad provided in said groove and extending radially so that its top bears against said cavity while allowing the fluid passage on its sides;
• it comprises at least a first and a second stage each of which corresponds distinctly to a set of two ducts, a working chamber, a groove and a seal.
• it comprises at least one cam and one guide pin, carried one by said piston, the other by said body, and arranged to cooperate reciprocally so that rotation of said piston relative to said body causes:
  • on a first angular portion, the axial translation in a first direction of said piston relative to said body,
  • on a second angular portion, the axial immobilization of said piston relative to said body,
  • on a third angular portion, the axial translation in a second direction of said piston relative to said body,
  • on a fourth angular portion, the axial immobilization of said piston relative to said body,
  • said ducts, said seal and said groove being arranged so that said ducts are closed during said second and fourth angular portions.

The invention extends to an oscillation-rotating pump device for fluid, characterized in that it comprises drive means and an oscillating-rotational subassembly for pumping a fluid and removable mechanical coupling means for mechanically connecting said drive means to said piston in a removable manner. So, for applications or microbiological control is important, the fluidic portion formed by the oscillating-rotational subassembly can be easily separated from the drive means to be sterilized and / or changed.

Brief presentation of the drawings

• les figures 1 à 3 sont des vues frontales du piston portant le joint d'étanchéité du sous-ensemble oscillo-rotatif selon un premier mode de réalisation de l'invention, illustré selon trois orientations différentes ;
• la figure 4 est une vue en perspective du joint d'étanchéité des figures 1 à 3 illustré seul ;
• la figure 5 est une vue en perspective de l'extrémité du piston des figures 1 à 3 portant un joint d'étanchéité ;
• les figures 6 à 11 sont des vues de face en transparence du sous-ensemble oscillo-rotatif selon le premier mode de réalisation de l'invention, illustré en six positions de fonctionnement distinctes lors d'un cycle de pompage (admission, commutation, refoulement, commutation) ;
• la figure 12 est une vue schématique en coupe de dessus du piston et du corps du premier mode de réalisation de l'invention, illustrant les angles fonctionnels des lignes d'étanchéité du joint d'étanchéité par rapport au positionnement et au dimensionnement des conduits. Etant donné la symétrie, seul l'un de chacun de ces angles est représenté.
• les figures 13 et 14 sont respectivement une vue en perspective éclatée et une vue en perspective coupée d'un sous-ensemble oscillo-rotatif selon un second mode de réalisation de l'invention ;
• les figures 15 à 20 sont des vues en coupe du sous-ensemble oscillo-rotatif des figures 13 et 14, illustré en six positions de fonctionnement distinctes lors d'un cycle de pompage. Le doigt de guidage n'est pas représenté sur ces figures ;
• la figure 21 est une vue en perspective du corps du sous-ensemble oscillo-rotatif des figures 1 à 11 illustrant la position à 180° des embouts de raccordement ;
• la figure 22 est un graphe simplifié illustrant l'évolution dans le temps de la pression (en ligne continue) dans la chambre de travail d'un dispositif oscillo-rotatif simple effet et le débit obtenu (en ligne de points) au cours de la rotation sur 1 tour complet du piston. Ce graphe n'illustre pas les phases de transition décrites plus loin ;
• la figure 23 est un graphe simplifié illustrant l'évolution dans le temps de la pression (en lignes continue et pointillée) dans chacune des chambres de travail d'un dispositif oscillo-rotatif double effet et le débit obtenu (en ligne de points) au cours de la rotation sur 1 tour complet du piston. Ce graphe n'illustre pas les phases de transition décrites plus loin ;
• la figure 24 est une vue en perspective du corps d'un sous-ensemble oscillo-rotatif dont les embouts sont parallèles entre eux ;
• la figure 25 est une vue en coupe radiale selon un plan passant par les axes des conduits du corps du sous-ensemble oscillo-rotatif de la figure 24.

Sur les figures 13 à 20, les éléments analogues à ceux des figures précédentes y sont affectés des mêmes numéros de référence, augmentés de 100.The present invention will be better understood and other advantages will appear on reading the detailed description of two embodiments taken as non-limiting examples and illustrated by the appended drawings, in which:

• the Figures 1 to 3 are front views of the piston bearing the seal of the oscillating-rotational subassembly according to a first embodiment of the invention, illustrated in three different orientations;
• the figure 4 is a perspective view of the seal of Figures 1 to 3 illustrated alone;
• the figure 5 is a perspective view of the end of the piston of Figures 1 to 3 bearing a seal;
• the Figures 6 to 11 are transparent front views of the oscillating-rotary subassembly according to the first embodiment of the invention, illustrated in six different operating positions during a pumping cycle (admission, switching, repression, switching);
• the figure 12 is a schematic sectional view from above of the piston and the body of the first embodiment of the invention, illustrating the functional angles of the sealing lines of the seal relative to the positioning and sizing of the ducts. Given the symmetry, only one of each of these angles is represented.
• the Figures 13 and 14 are respectively an exploded perspective view and a cutaway perspective view of an oscillating-rotational subassembly according to a second embodiment of the invention;
• the Figures 15 to 20 are sectional views of the turret-rotary subassembly of Figures 13 and 14 , illustrated in six operating positions during a pumping cycle. The guide finger is not shown in these figures;
• the figure 21 is a perspective view of the body of the turret-rotary subassembly of Figures 1 to 11 illustrating the 180 ° position of the connection ends;
• the figure 22 is a simplified graph illustrating the evolution over time of the pressure (in continuous line) in the working chamber of a single-acting oscillating-rotary device and the flow obtained (in line of points) during the rotation on 1 complete turn of the piston. This graph does not illustrate the transition phases described below;
• the figure 23 is a simplified graph illustrating the evolution over time of the pressure (in continuous and dashed lines) in each of the working chambers of a double-acting oscillating-rotary device and the flow obtained (in line of points) during the rotation on 1 full turn of the piston. This graph does not illustrate the transition phases described below;
• the figure 24 is a perspective view of the body of an oscillating-rotary subassembly whose ends are parallel to each other;
• the figure 25 is a radial sectional view along a plane passing through the axes of the ducts of the body of the oscillating-rotary subassembly of the figure 24 .

On the Figures 13 to 20 elements similar to those of the preceding figures are assigned the same reference numbers, increased by 100.

Description of the embodiments

The oscillation-rotating subassembly for pumping according to the invention may have a single stage single-effect configuration, hereinafter described as a first embodiment illustrated by the Figures 1 to 11 , and a multistage multi-effect configuration, for example the double-acting configuration described later as a second illustrated embodiment by the Figures 12 to 19 .

With reference to Figures 6 to 11 , the oscillating-rotary subassembly 1 according to the first embodiment of the invention comprises a body 2 and a piston 3.

As detailed on the figure 7 , the body 2 is hollow and formed of two cylindrical portions 4, 5 of different diameters interconnected by a shoulder 6. The body 2 is for example made of plastic material or any other suitable material.

The inside of the cylindrical portion 4 of large diameter forms a bore 7 of longitudinal axis A. The free end of this cylindrical portion 4 of large diameter is open and intended to receive the longitudinal engagement of the piston 3. The other end is connected to the cylindrical portion of small diameter 5 by the shoulder 6. The wall of the cylindrical portion 4 of large diameter is traversed by an orifice 8 for receiving a radial guide pin 9 arranged to protrude into the 7. In the illustrated example, the guide pin 9 is a pin. The guide finger 9 may also be secured to the body by gluing or by any other suitable means. The guide pin 9 has for example a cylindrical section or any other adapted section.

The inside of the cylindrical portion 5 of small diameter defines a cavity 10 of longitudinal axis A and of smaller diameter than that of the bore 7. The free end of the cylindrical portion 5 of small diameter is closed and forms the bottom of the body 2. The bore 7 and the cavity 10 are intended to receive the piston 3 housed in the body 2. The wall of the cylindrical portion 5 of small diameter is traversed by two ducts 11, 12 opening radially into the cavity 10. These ducts 11, 12 have for example a circular section and have the same diameter and are coaxial with each other, diametrically opposite to each other and situated in the same radial plane perpendicular to the longitudinal axis A. Thus, in this case, embodiment, the mouths of the ducts 11, 12 in the cavity 10 are coaxial with each other, diametrically opposed to each other and located in the same radial plane. As illustrated in particular by the figure 21 , the body 2 comprises connecting tips 13, 14 individually surrounding each of the ducts 11, 12 and adapted to be connected for example to an inlet pipe or a discharge pipe or other suitable fluid connection material. Thus, the connection ends 13, 14 are offset from each other by an angle of 180 °. As described below, according to the chosen operating configuration, each of the ducts 11, 12 can equally be used for admission or for delivery of the fluid.

According to another embodiment not shown, the ducts may be slightly offset longitudinally relative to each other.

According to the embodiment illustrated by the Figures 24 and 25 , the mouths of the ducts may be offset from one another by a 180 ° angle while having ducts 11, 12 with a return allowing the end pieces to have an angle other than 180 °. In this example, the connecting tips 13, 14 are parallel to each other which can simplify the fluid connection configuration. On the same principle, while having the mouths of the ducts offset from one another by a 180 ° angle, one can have connecting end pieces 13, 14 having between them any other suitable angle. The same is true for pipe mouths offset by an angle other than 180 °.

According to another embodiment, the ducts may also be offset from each other by an angle other than 180 °.

With particular reference to Figures 1 to 5 , the piston 3 is formed of two cylindrical portions 15, 16 of different diameters interconnected by a shoulder 17. The piston 3 is for example made of plastic material or any other suitable material.

The cylindrical portion 16 of small diameter of the piston 3 has an outer diameter less than the diameter of the cavity 10 in which it can thus be accommodated. In the illustrated example, the cylindrical portion 16 of small The diameter of the piston 3 is made in two parts including an axis 19, integral with the rest of the piston 3 and having a diameter reduction, and a sleeve 20, attached to the reduced diameter portion of the axis 19, and whose diameter outside corresponds to the outer diameter of the axis 19. This cylindrical portion 16 of small diameter of the piston 3 can also be made in a single part.

With reference to the figure 4 , the sleeve 20 comprises an axial recess 21, and is for example secured to the axis 19 by force fitting, supplemented or not by gluing or by any other suitable means. This sleeve 20 may alternatively be made by overmolding on the axis 19. With particular reference to Figures 6 to 10 , the free end of the sleeve 20 defines, with the bottom of the body 2, a working chamber 31 for receiving the fluid.

The sleeve 20 comprises, on its periphery, a groove 22 extending longitudinally between a closed end 23 facing the cylindrical portion 15 of large diameter of the piston 3 and an open end 24 opening into the working chamber 31. In the example illustrated, the bottom of the groove 22 has a curved curved profile parallel to the longitudinal axis A. This profile may be different, for example flat by means of a flat, recessed curved, or any other adapted profile. In the illustrated example, the groove 22 is delimited by longitudinal edges substantially parallel to the longitudinal axis A and by transverse edges in an arc of a circle each located in a plane substantially perpendicular to the longitudinal axis A. The groove 22 has thus generally a tubular portion shape. The groove 22 may also have the shape of an inclined line, a cross or any other form adapted to the oscillatory-rotary movement of the piston 3. The sleeve 20 comprises, a balancing stud 25 provided in the groove 22, at its open end 24 and extending radially so that its top bears against the cavity 10 while allowing the passage of fluid on its sides. The balancing pad 25 is for example provided in the middle of the groove 22.

With reference in particular to the figure 4 , the sleeve 20 is provided with a peripheral groove having an annular groove 26, a half-annular groove 27 and two longitudinal grooves 28 interconnecting the annular groove 26 and the half-annular groove 27. According to an alternative embodiment not shown , the sleeve has a single longitudinal groove.

The annular groove 26 is hollowed in a plane perpendicular to the longitudinal axis A, and provided axially beyond the closed end 23 of the groove 22 relative to the open end 24 of the same groove 22, and beyond beyond the ducts 11, 12 with respect to the working chamber 31 when the piston 3 is in the body 2, even when the piston 3 is in its low position.

The half-annular groove 27 is hollowed parallel to the annular groove 26 in a plane perpendicular to the longitudinal axis A, and provided axially at the open end 24 of the groove 22. Thus, even when the piston 3 is in its high position in the body 2, the half-annular groove 27 is arranged axially between the ducts 11, 12 and the working chamber 31.

In the illustrated example, the longitudinal grooves 28 are hollowed parallel to the longitudinal axis A and connect the annular groove 26 and the ends of the half-annular groove 27. Thus, the groove 22 is framed on the one hand by the longitudinal grooves 28 and, secondly, by a portion of the annular groove 26. The longitudinal grooves 28 may also have a variable width along the longitudinal axis A and for example have an hourglass shape.

The sleeve 20 also comprises, on its periphery, a recessed area 29 closed, angularly opposite the groove 22. Each longitudinal groove 28 is disposed between the groove 22 and the recessed area 29. The recessed area 29 is thus framed, a part through the longitudinal grooves 28 and, secondly, by the half-annular groove 27 and a portion of the annular groove 26. This recessed area 29 limits the surface of the piston 3 in contact with the cavity 10 and thus to limit the friction. Thus, the oscillation-rotary displacement of the piston 3 is done with a good energy efficiency.

The end of the cylindrical portion 16 of small diameter of the piston 3 opposite the working chamber 31 is connected to the cylindrical portion 15 of large diameter of the same piston 3.

The cylindrical portion 15 of large diameter of the piston 3 has an outer diameter smaller than the diameter of the bore 7 in which it can thus be accommodated. The free end of the cylindrical portion 15 of large diameter has a hollow form 18 in the form of a cross (visible on the figure 5 ) intended to receive a complementary shape (not shown) coupled to the drive means for rotating the piston 3 relative to the body 2. The hollow form 18 may have any other profile adapted to a rotational drive, it can also be provided in relief. However, a recessed shape has the advantage of being less accessible, the position of the piston 3 can thus be less easily modified manually before use of the oscillating-rotary subassembly 1. Thus, when the first use, the position of the piston is known which ensures the operating phase at startup (suction, switching, discharge) and therefore to know precisely the dose transferred. For the same purpose, the recessed shape may be provided to require the use of a specific tool to be operated. The cylindrical portion 15 of large diameter of the piston 3 comprises two annular ribs 30 parallel to each other so as to define between them a double guide cam of the guide pin 9. Thus, the longitudinal spacing between the annular ribs 30, in all point of rotation to the right of the guide pin 9, is adjusted to the dimensions of the guide pin 9 to allow this guidance without play or excessive play. The guide pin 9 may also be provided with a rotating portion intended to roll on the annular ribs 30 and thus reduce friction. The energy efficiency is thus optimized. The annular ribs 30 each comprise a first and a second inclined portion SI1, SI2, symmetrical to one another with respect to a median longitudinal plane. The first and second inclined portions SI1, SI2 thus have inverted slopes on the periphery of the piston 3. The first and second inclined portions SI1, SI2 are separated from each other by first and second planar portions SP1, SP2 substantially parallel to each other and perpendicular to the longitudinal axis A. Thus, by means of the guide pin 9 and the annular ribs 30, the rotation in a first direction of rotation R of the piston 3 relative to the body 2, successively causes the axial translation of the piston 3 with respect to the body 2 in a first direction of translation T1 along the first inclined portion SI1, then the axial immobility of the piston 3 with respect to the body 2 along the first flat portion SP1, then the axial translation of the piston 3 relative to the body 2 in a second direction of translation T2 along the second inclined portion SI2, and finally the axial immobility of the piston 3 relative to the body 2 the ng of the second flat portion SP2, and so on. The piston 3 thus oscillates between a high position (Cf. figure 8 ) in which the working chamber 31 has a maximum volume and a low position in which the working chamber 31 has a minimum volume. Between these two positions of the piston 3, the working chamber 31 admits and then represses the fluid.

The piston 3 carries a seal housed in the peripheral groove, and made of a material having a modulus of elasticity lower than that of the piston 3 and the body 2. It is for example made of elastomer and is dimensioned so that, when the piston 3 is in the cavity 10, the seal is in contact with the inner wall of the cavity 10.

This seal is formed of a sealing torus 32 and a half-torus 33 coaxial and parallel to each other, connected to one another by two sealing tongues 34. piston has only one longitudinal groove, the seal has only one sealing tongue.

In the example shown, the sealing tongues 34 are arranged at 180 ° to one another. However, the sealing tabs 34 may be arranged otherwise provided that the geometrical constraints detailed below are respected. The sealing tabs 34 may have a constant width along the longitudinal axis A or a variable length to accommodate a variable width of the groove 22.

The sealing torus 32 is housed in the annular groove 26, the half-torus seal 33 is housed in the half-annular groove 27 and each sealing tongue 34 is housed in one of the longitudinal grooves 28. Thus, in any angular and axial position of the piston 3 in the body 2, the sealing torus 32 is axially located beyond the conduits 11, 12 with respect to the working chamber 31, the half-torus sealing 33 is axially located between the conduits 11, 12 and the working chamber 31. The seal seals around the recessed area 29 and around the groove assembly 22 and working chamber 31 ensuring fluid communication between the groove 22 and the working chamber 31.

Each sealing tongue 34 defines a first and a second sealing line L1, L2 (visible on the figures 4 and 12 ) extending longitudinally and angularly offset from each other. As illustrated by figure 12 the groove 22 is thus angularly bordered by the first sealing lines L1 of each of the two sealing tabs 34, and the recessed area 29 is angularly bordered by the second sealing lines L2 of each of the two sealing tabs. 34. The recessed area 29 makes it possible to limit the area of the seal in contact with the cavity 10 and thus to limit the friction. For the same purpose, according to an alternative embodiment not shown, each sealing tongue can be hollowed out.

• les premières lignes d'étanchéité L1 sont séparées entre elles d'un angle α1 passant par la rainure 22, supérieur à chacun des angles β1 séparant les bords d'un même conduit 11, 12, et inférieur à chacun des angles β2 séparant les bords adjacents d'un conduit 11 et de l'autre conduit 12,
• chaque seconde ligne d'étanchéité L2 est séparée d'une des premières lignes d'étanchéité L1 d'un angle α2 ne passant pas par la rainure 22, inférieur à chaque angle β2 et supérieur à chaque angles β1,
• l'angle α3 séparant chaque première ligne d'étanchéité L1 d'au moins une des secondes lignes d'étanchéité L2 en passant par la rainure 22 est supérieur à l'angle β3 séparant les bords axialement opposés des conduits 11, 12.

With reference in particular to the figure 12 , the body 2, the piston 3 and the seal are arranged to respect the following geometrical constraints:

• the first sealing lines L1 are separated from each other by an angle α1 passing through the groove 22, greater than each of the angles β1 separating the edges of the same duct 11, 12, and less than each of the angles β2 separating the edges adjacent to one duct 11 and the other duct 12,
• each second sealing line L2 is separated from one of the first sealing lines L1 by an angle α2 not passing through the groove 22, smaller than each angle β2 and greater than each angle β1,
• the angle α3 separating each first sealing line L1 from at least one of the second sealing lines L2 through the groove 22 is greater than the angle β3 separating the axially opposite edges of the ducts 11, 12.

The single-acting oscillating-rotary subassembly 1 is thus provided with a single stage comprising two ducts 11, 12, a working chamber 31, a groove 22 and a recessed area 29. Thus, with a pair of ducts 11, 12 said intake and discharge, corresponds to a single groove 22.

To operate the single-acting oscillating-rotary subassembly 1, one of the conduits 11, 12 is connected to a fluid supply pipe, the other to a discharge pipe of this same fluid, and the piston 3 is mechanically connected, through the hollow form 18, to rotary drive means (not shown) of known type. The operation of the single-acting tilt-rotary subassembly 1 according to the invention is described below with reference to the Figures 6 to 11 and to the graph of the figure 22 .

In the admission phase illustrated by the Figures 6 and 7 and the "Adm phase" of the figure 22 , the guide pin 9 circulates mainly along the first inclined portion SI1 of the cam which converts the rotation R of the piston 3 into a first translation T1 in a first direction of movement of the piston 3 relative to the body 2 which passes the piston 3 from a low position ( figure 11 ) in which the working chamber 31 has a minimum volume at a high position ( figure 7 ) in which the working chamber 31 has a maximum volume. During the intake phase, the piston 3 rotates relative to the body 2 with the groove 22 flowing in front of the orifice of the conduit 11 said admission. Thus the duct 11 said admission is in fluid communication with the working chamber 31 through the groove 22, and the fluid is sucked, by increasing the volume of the working chamber 31 caused by the first translation T1 and creating a depression in the working chamber 31 according to the arrow E. During this intake phase, the recessed area 29 flows in front of the orifice of the conduit 12 called discharge. The seal ensures the sealing of the conduit 12 said discharge which is not in fluid communication with the working chamber 31, which is schematized by a cross. Thus, during the intake phase via the intake duct 11, the fluid does not leave the working chamber 31 through the duct 12, said discharge. The rotation R of the piston 3 with respect to the body 2 is extended until reaching a first switching phase. Advantageously, at the beginning of the intake phase, during a transition phase, the guide pin 9 circulates on the end of the second flat portion SP2. Similarly, at the end of the intake phase, during a transition phase, the guide pin 9 flows on the beginning of the first flat portion SP1 of the cam. Thus the transition phases occur at constant volume of the working chamber 31. For the sake of simplification, these transition phases are not represented on the graph of the figure 22 .

In this first switching phase illustrated by the figure 8 and one of the "Comm Phase" of the figure 22 , the guide pin 9 flows along the first flat portion SP1 of the cam. The rotation R of the piston 3 then does not cause its translation and the piston 3 is axially stationary in its high position. Thus, the volume of the working chamber 31 does not vary and remains maximum. During this switching phase, the orifice of the duct 11 said intake and the orifice of the duct 12 said discharge are each opposite one of the sealing tabs 34 which prevent any fluid communication with one or other of the ducts 11, 12 said admission or discharge. Thus the working chamber 31 is fluidly sealed. The rotation R of the piston 3 relative to the body 2 is extended until reaching the discharge phase.

In this phase of repression illustrated by the Figures 9 and 10 and the "Ref phase" of the figure 22 , the guide pin 9 circulates mainly along the second inclined portion SI2 of the cam which converts the rotation R of the piston 3 into a second translation T2 in a second direction of displacement opposite to the first direction of movement during translation T1. Thus, the piston 3 moves from its high position ( figure 8 ) at its low position ( figure 11 ). During the discharge phase, the piston 3 rotates relative to the body 2 with the groove 22 flowing in front of the orifice of the pipe 12 said discharge. Thus the discharge conduit 12 is in fluid communication with the working chamber 31 via the groove 22, and the fluid is discharged, by reducing the volume of the working chamber 31 caused by the second translation T2 and creating an overpressure along the arrow S in the working chamber 31 by the conduit 12 said discharge. During this discharge phase, the recessed area 29 circulates in front of the orifice of the inlet duct 11. The seal ensures the sealing of the inlet duct 11, which is not in fluid communication with the working chamber 31. Thus, during the discharge phase via the discharge duct 12, the fluid between not in the working chamber 31 by the conduit 11 said admission. The rotation R of the piston 3 with respect to the body 2 is extended until reaching a second switching phase. Advantageously, at the beginning of discharge, during a transition phase, the guide pin 9 flows on the end of the first planar portion SP1. Similarly, at the end of the discharge phase, during a transition phase, the guide pin 9 flows on the beginning of the second flat portion SP2 of the cam. Thus the transition phases occur at constant volume of the working chamber 31. For the sake of simplification, these transition phases are not represented on the graph of the figure 22 .

This second switching phase, illustrated by the figure 11 and the other "Comm phase" of the figure 22 , is substantially similar to the first switching phase. It is distinguished by the piston 3 in the low position, the working chamber 31 which has a minimum volume and the position of the sealing tongues 34 relative to the ducts 11, 12 called intake and discharge, inverted relative at the first switching phase.

The tilt-and-turn cycle can be repeated. It is understood that, according to the direction of rotation of the piston 3 relative to the body 2, the inlet duct may correspond to the discharge duct and vice versa. During displacements of the piston 3 in the cavity 10, the contact between the balancing stud 25 and the wall of the cavity 10 prevents the piston 3 from tilting with respect to the longitudinal axis A, which would cause an increase in the friction, the appearance of leaks, or even a blockage of the piston 3 in the body 2.

By modifying the profiles of the first and second inclined portions SI1, SI2 as well as the positioning of the first and second sealing lines L1, L2, the ratio between the intake phase and the discharge phase can be adjusted. It is thus possible to extend the duration of one or the other of these phases of admission and discharge with respect to the other.

The oscillating-rotary subassembly 101 according to the second embodiment of the invention is illustrated by the Figures 13 to 20 and has a dual-effect configuration. For this purpose, it comprises two stages, a first stage similar to that of the oscillating-rotary subassembly 1 and a second stage comprising two conduits 111, 112, a working chamber 131, a groove 122, a recessed area 129 such that those of the first floor. Thus, each pair of pipes 11, 12 called intake and discharge, corresponds to a single groove 22, 122.

In the illustrated example, the admission ducts 11, 111 are superposed between them longitudinally, the conduits 12, 112 said discharge are superimposed between them longitudinally, the grooves 22, 122 are located 180 ° from each other and the recessed areas 29, 129 are located at 180 ° the one of the other. The fluidic connections through the ducts 11, 111 known as intake and the ducts 12, 112 known as intake are at 180 °. The body 102 has a cavity 110 longitudinally having a higher height for accommodating the two stages. The body 102 also comprises an annular groove 135, coplanar with the shoulder 106 separating the cavity 110 and the bore 107, oriented towards the inside of the body 102 and intended to receive, for example, a complementary seal 36 or any other sealing member ensuring the seal between the piston 103 and the body 102. Thus, as illustrated by the graph of the figure 23 when a stage is in the admission phase ("Adm phase") with the groove 22, 122 facing the duct 11, 111 said admission, the other stage is in the discharge phase ("phase Ref") with the groove 22, 122 facing the duct 12, 112 called discharge ( Figures 16, 17, 19 and 20 ). As for the oscillating-rotary subassembly 1, during the switching phases, the so-called intake ducts 11, 111 and the discharge ducts 12, 112 are sealed ( Figures 15 and 18 ).

According to a first configuration, the so-called inlet ducts 11, 111 of each stage can be fluidically connected to a common inlet of the same fluid and the so-called discharge ducts 12, 112 of each stage can be fluidically connected to a common outlet of the same fluid.

According to a second configuration, the double-acting oscillating-rotational subassembly can advantageously be used to produce mixtures using a stage for a first fluid and another stage for a second fluid, the pipes 12, 112 known as delivery pipes of each stage being for example connected to the same container for receiving the mixture obtained. By modifying the ratio between the working chambers 31, 131 and if possible the sections of the ducts 11, 111, 12, 112, the dosage of the mixture obtained can be varied.

In these two configurations, the flow rate of the pumping device incorporating such a double-effect oscillo-rotary subassembly 101 will be increased, with a pulse frequency that is twice as high, relative to a single-acting oscillating-rotary subset 1. .

According to a third configuration the conduit 12 said delivery of a stage can be fluidly connected to the conduit 11, said admission, the other floor. In this third configuration, the sucked fluid passes successively through the working chambers 31, 131. It is possible to accumulate in cascade the discharge pressures generated by each stage.

According to a fourth configuration, the two stages can be identical and simply offset from one another longitudinally. Thus, the two phases of admission of the two stages are concomitant with each other, and the two phases of discharge of the two stages are concomitant with each other. In this case, the flow rate of the pumping device incorporating such a double-acting oscillating-rotational subassembly 101 will be doubled with an identical pulse frequency with respect to a single-effect tilt-rotary subassembly 1.

According to another embodiment, not shown, each so-called intake duct is angularly offset from the corresponding discharge duct by a predetermined angle, the grooves are angularly offset from each other by the same predetermined angle and the recessed areas are also angularly offset from one another. same predetermined angle. The fluidic connections through the so-called intake ducts and the so-called intake ducts are in separate longitudinal planes angularly offset from the predetermined angle. This angle can be chosen to facilitate the spatial organization of the fluidic connections. This embodiment can be combined with the various configurations detailed above.

The invention achieves the previously mentioned objectives. Indeed, the oscillating-rotary subassembly 1, 101 according to the invention is simple to manufacture with a limited number of parts. The seal makes it possible to limit the geometrical constraints to be respected and facilitates the manufacture of the oscillating-rotational subassembly 1, 101. It is also easier to assemble and the recessed area 29, 129 makes it possible to improve its energy efficiency.

The oscillating-rotary subassembly 1, 101 makes it possible to ensure a precise flow independent of the user and / or the viscosity of the fluid. It can be coupled to an angular position sensor.

Furthermore, the oscillating-rotational subassembly 1, 101 according to the invention is reversible, simply by inverting the direction of rotation of the piston 3, 103. Thus the duct 11, 111 called admission becomes duct 12, 112 called repression and vice versa. The mechanical decoupling between the piston 3, 103 and the drive means make it possible to obtain a disposable tilt-rotary subassembly while the driving part is reusable. This ensures, at lower cost, the sterility of the tilt-rotary subassembly 1, 101 by replacing it between two uses. Thus, only the fluidic portion of the tilt-rotary pumping device is to be renewed, the motorization and control parts being kept between two uses. The fact that the axial forces are transmitted by the cam, allows the use of drive means limited to rotation, and mechanical coupling means between the piston 3 and these drive means limited to the simple transmission of a couple. The cam also makes it possible to ensure that the reciprocating translation of the piston 3 is synchronous with the rotation of the same piston 3.

The oscillating-rotational subassembly 1, 101 according to the invention prohibits any fluid flow with the ducts 11, 111, 12, 112 called inlet and discharge during the switching phases, without creating an overpressure effect. or depression by hydraulic blockage during these phases. It also allows to limit the dead volume.

The contact between the seal and the body makes it possible to angularly wedge the oscillating-rotational subassembly 1, 101 at the factory during its initial assembly. This angular setting will thus be easily preserved until the start of operation of the oscillating-rotational subassembly 1, 101 in the rotary-oscillation device. It is nevertheless possible to provide a visual reference of the angular position of the piston 3, 103 relative to the body 2, 102 or a sensor of any suitable technology.

It goes without saying that the present invention can not be limited to the foregoing description of one of its embodiments, may undergo some modifications without departing from the scope of the invention as defined by the claims.

Claims (9)

1. A rotary-oscillating sub-assembly (1; 101) for positive displacement pumping of a fluid, said sub-assembly comprising: a hollow body (2; 102) defining a cylindrical cavity (10; 110) of longitudinal axis (A) and having a wall with at least two ducts (11, 12; 111, 112) passing therethrough and opening out radially into said cavity (10; 110); a piston (3; 103) housed in said cavity (10; 110) with which it co-operates to define a working chamber (31; 131) and including, in its cylindrical surface, a longitudinal channel (22; 122) or recess that opens out longitudinally into said working chamber (31; 131), said piston (3; 103) being provided with a sealing gasket (32, 33, 34) that is made of a material having a modulus of elasticity that is less than the moduli of elasticity of said piston (3) and of said body (2), and that is carried by said piston (3; 103), the gasket running beside said channel so as to guarantee leaktight sealing between said piston (3; 103) and said cavity (10; 110), the piston being movable angularly so as to put said working chamber (31; 131) into fluid-flow communication with at least one, then none, then at least the other of said ducts (11, 12; 111, 112), and being movable in longitudinal translation to reciprocate so as to cause the volume of said working chamber (31; 131) to vary and successively suck in and then discharge said fluid via one then the other of said ducts (11, 12; 111, 112), said sub-assembly being characterized in that the piston (3; 103) includes a first axial end remote from a second axial end, said second axial end being in contact with the working chamber (31; 131);

   • said sealing gasket (32, 33, 34) is made up of a plurality of portions comprising: a first sealing portion in the shape of a ring (32) that extends around the cylindrical surface of the piston (3; 103) beside its first axial end; a second sealing portion in the shape of a half-ring (33) that extends around the cylindrical surface of the piston (3; 103) beside its second axial end, the half-ring (33) having two ends that are spaced apart from each other over the cylindrical periphery of the piston; and a third sealing portion that is formed by two sealing strips (34) that extend axially over the outside surface of the piston (3; 103) respectively between a first end of the half-ring (33) and the ring (32), and between a second end of the half-ring (33) and the ring (32);

   in that the two strips (34) are angularly offset from each other and each defines:

   • a first sealing line (L1) that angularly borders said channel (22; 122), said first sealing lines (L1) being spaced apart from each other by an angle (α1) containing said channel (22; 122), that is greater than each of the angles (pi) between the edges of either one of the ducts (11, 12; 111, 112), and that is less than each of the angles (p2) between the adjacent edges of either one of the ducts (11; 111) and of its corresponding duct (12; 112);

   • and a second sealing line (L2), each second sealing line (L2) being spaced apart from one of said first sealing lines (L1) by an angle (α2) that does not contain said channel (22; 122), that is less than each angle (β2) between the edge of one duct (11; 111) and the adjacent edge of its corresponding duct (12; 112), and that is greater than each angle (β1) between the opposite edges of either one of the ducts (11, 12; 111, 112); and in that

   • the angle (α3) between each first sealing line (L1) from at least one of the second sealing lines (L2), and containing said channel (22; 122), is greater than the angle (β3) between the axially-opposite edges of the two ducts (11, 12; 111, 112).
2. A rotary-oscillating sub-assembly (1; 101) according to claim 1, characterized in that said piston (3; 103) includes a peripheral groove that receives said sealing gasket (32, 33, 34), which peripheral groove is formed of at least one annular groove (26) that receives said sealing ring (32), a semi-annular groove (27) that receives said sealing half-ring (33), and a longitudinal groove (28) that interconnects said annular groove (26) and said semi-annular groove (27) and that receives said sealing strip (34).
3. A rotary-oscillating sub-assembly (1; 101) according to claim 2, characterized in that at least one of said sealing ring (32) and annular channel (26) extends longitudinally beyond said channel (22; 122) relative to said working chamber (31; 131) and beyond said ducts (11, 12; 111, 112) relative to said working chamber (31; 131), and in that at least one of said sealing half-ring (33) and semi-annular groove (27) extends longitudinally at said end of said channel (22; 122) opening out into said working chamber (31; 131) and between said ducts (11, 12; 111, 112) and said working chamber (31; 131).
4. A rotary oscillating sub-assembly (1; 101) according to claim 2, characterized in that, in its periphery, said piston (3; 103) includes at least one closed recessed zone (29; 129) that is entirely surrounded by said sealing gasket (32, 33, 34), said recessed zone (29; 129) extending angularly so as to be facing one of the ducts (11, 12; 111, 112) when said channel (22; 122) is facing another duct (12, 11; 112, 111), said longitudinal groove (28) being formed of two arms, each extending between said channel (22; 122) and said recessed zone (29; 129), and in that each arm receives one of said sealing strips (34) so as to isolate said recessed zone (29; 129) from said channel (22; 122) in leaktight manner, in any longitudinal and angular position of said piston (3; 103) in said body (2; 102).
5. A rotary-oscillating sub-assembly according to claim 4, characterized in that said recessed zone (29; 129) extends over an angle that is less than each of the angles (β2) between adjacent edges of either one of the ducts (11; 111) and of its corresponding duct (12; 112).
6. A rotary-oscillating sub-assembly (1) according to claim 1, characterized in that said piston (3) includes at least one balancing lug (25) that is provided in said channel (22) and that extends radially so that its periphery bears against said cavity (10) while allowing fluid to pass over its sides.
7. A rotary-oscillating sub-assembly (101) according to claim 1, characterized in that it includes at least first and second stages, each corresponding, in distinct manner, to a set of two ducts (11, 12, 111, 112), to a working chamber (31; 131), to a channel (22; 122), and to a sealing gasket (32, 33, 34).
8. A rotary-oscillating sub-assembly (1; 101) according to claim 1, characterized in that it includes at least a cam (30) and a guide finger (9), one carried by said piston (3; 103), the other by said body (2; 102), and arranged to co-operate reciprocally so that turning said piston (3; 103) relative to said body (2; 102) causes:

   • over a first angular portion, said piston (3; 103) to move in axial translation (T1) relative to said body (2; 102) in a first direction;

   • over a second angular portion, said piston (3; 103) to be axially stationary relative to said body (2; 102) ;

   • over a third angular portion, said piston (3; 103) to move in axial translation relative to said body (2; 102) in a second direction;

   • over a fourth angular portion, said piston (3; 103) to be axially stationary relative to said body (2; 102) ;

   said ducts (11, 12; 111, 112), said sealing gasket (32, 33, 34), and said channel (22; 122) being arranged so that said ducts (11, 12; 111, 112) are closed during said second and fourth angular portions.
9. A rotary-oscillating device for positive displacement pumping of a fluid, the device being characterized in that it comprises drive means and a rotary-oscillating sub-assembly (1; 101) for positive displacement pumping of a fluid according to any preceding claim, and releasable mechanical coupler means for mechanically connecting said drive means to said piston (3; 103) in releasable manner.

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