EP3824183A1

EP3824183A1 - Precision, constant-flow reciprocating pump

Info

Publication number: EP3824183A1
Application number: EP19842361.8A
Authority: EP
Inventors: Florent Junod; Thierry Navarro
Original assignee: Swissinnov Product SARL
Current assignee: Swissinnov Product SARL
Priority date: 2018-10-14
Filing date: 2019-10-10
Publication date: 2021-05-26
Also published as: WO2020078825A1; KR20210075100A; BR112021006246A2; JP2022502591A; CN112840124B; US20210293226A1; AU2019360341A1; CN112840124A; US11867162B2; CA3115604A1

Abstract

Disclosed is a pump comprising two pistons which are driven by a cam belonging to an external rotor and which are inserted into two cylinder blocks mounted parallel to each other in such a way as to form two opposite, parallel, eccentric pump chambers which have at least one inlet port through which liquid is drawn into the pump chambers during the fill stroke of the pistons, and then expelled from the pump chambers during the discharge stroke of the pistons to at least one outlet port, the outflow rate of which is constant and even.

Description

CONTINUOUS FLOW PRECISION PRECISION PUMP

The invention relates to a positive displacement pump consisting of two pistons for the precise and variable delivery of liquid, medicine, food, detergent, cosmetic, chemical compound or any other type of fluid, gel or gas. The prior art

There are different pumps with cam as described in patent PCT / IB2013 / 059393, the operating principle of which consists in driving a rotor containing two cylinders and pistons to obtain a flow without pulsation.

In patent PCT / IB2013 / 059393, the drive of each piston is done by means of an axis guided by one or both ends of the axis traveling in a cam placed in the stator and optionally by another similar opposite cam in the cover. This mechanism is integrated in the interchangeable fluid module or pump head, made of plastic for single use.

The main problem encountered by this system stems from the fact that the piston drive elements are integrated into the interchangeable fluid module, made of economical plastic, impacting the precision of the pump since the stroke of the pistons depends on the quality of the movement imparted. on the guide pins along the cam. The wear of the plastic parts reduces the life of the pump head which in some cases even results in the rupture of the cam when heating due to the friction of the axes along the cam is prolonged. The lateral supports of the cam can also deform or even break when the pressure in the pump increases, which limits the use of this type of pump for applications requiring pressures greater than a few bars. Another disadvantage is that the seal between the rotor and the stator is made using a circular seal which undergoes unidirectional circular friction during the operation of the pump, thus creating significant localized heating on the rotor. which can quickly deform and make the pump inoperative. Description of the invention

The present invention relates to an efficient pump composed of a reduced number of parts at very low production cost for pumping and dosing liquids, viscous products or gases with variable flow without pulsation.

This invention solves the problems set out above, by controlling the movements of the pistons and of the valve switching element, preferably linearly and parallel to each other, by a single rotor positioned in a drive mechanism of the external pump. interchangeable fluid module. All movements of the drive mechanism are carried out by robust, precise standard guiding elements, ensuring reliable guiding of the pistons and capable of withstanding very high pressures in the pump. It is thus possible to produce a variable flow pump without pulsation, very precise, durable and suitable for applications requiring pressures greater than a few bars.

The production of the pump head is also more economical since the latter advantageously comprises a reduced number of elements in contact with the fluid, that is to say two preferably identical cylinder blocks, two preferentially identical pistons, a valve switching element and preferably seals. The pumping principle consists in driving a rotor placed, in the pump mechanism, provided with a guide cam groove making it possible to move the pistons independently axially in the cylinder blocks by means of carriages. This cam groove is composed of six segments: a drain start segment at a flow rate lower than the nominal pump flow rate a long drain segment at the nominal pump flow rate

a drain end segment at a flow rate lower than the nominal pump flow rate

a valve switching segment switching between the outlet port and then the inlet port on the pumping chamber

a filling segment

a valve switching segment switching between the inlet port and then the outlet port on the pumping chamber

During the emptying phase of a chamber at the nominal flow rate of the pump, the other chamber switches from the outlet port to the inlet port, then fills completely and switches from the inlet port to the outlet port. On the other hand, the two chambers simultaneously expel towards the outlet port each at a reduced rate according to the two start and end drain segments, placed in opposition on the cam. The sum of these two reduced flow rates is equivalent to the nominal flow rate of the pump so that the output flow rate always remains equivalent to the nominal flow rate, continuous, uninterrupted and without pulsation. The rotor also includes an eccentric axis enabling the switching element of the valves to be moved, via a valve carriage, in synchronization with the pumping movements of the pistons. Description of the drawings

The present invention will be better understood on reading the description of the examples given, for information only and in no way limiting, with reference to the appended drawings in which:

Figure 1 is a view of the interchangeable fluid module.

Figure 2 is a bottom view of the interchangeable fluid module.

Figure 3 is an overview of the pumping mechanism.

Figure 4 is an overview of the pumping mechanism with the interchangeable fluid module inserted.

Figure 5 is an exploded view of the interchangeable fluid module.

Figure 6 is a view of the valve switching element.

Figure 7 is a front view of the invention.

Figure 8 is a top view of the invention.

FIG. 9 is a sectional view along the line A- A of FIG. 7.

FIG. 10 is a sectional view along line C-C of FIG. 7.

FIG. 11 is a sectional view along the line B -B in FIG. 8.

FIG. 12 is a sectional view along the line E-E of FIG. 8.

FIG. 13 is a sectional view along line D-D of FIG. 8.

FIG. 14 is a sectional view along line F-F of FIG. 7.

FIG. 15 is a graph showing the linear displacements of the pistons as a function of the angular displacement of the superimposed rotor with a second graph representing the state of the valves as a function of the angle of the axis of the valves. FIG. 16 is a view of the interchangeable fluid module produced by plastic injection.

FIG. 17 is an exploded view of the interchangeable fluid module produced by plastic injection.

Figure 18 is a front view of the interchangeable fluid module.

FIG. 19 is a sectional view along the line G-G of FIG. 18.

FIG. 20 is a sectional view along line I-I of FIG. 18.

FIG. 21 is a view of a variant of the fluid module interchangeable with the switching element of the cylindrical valves.

FIG. 22 is an exploded view of the variant of the fluid module interchangeable with the switching element of the cylindrical valves.

FIG. 23 is a front view of the variant of the fluid module interchangeable with the switching element of the cylindrical valves.

FIG. 24 is a sectional view along line D-D of FIG. 23.

FIG. 25 is a sectional view along the line A- A of FIG. 23.

FIG. 26 is a side view of the variant of the fluid module interchangeable with the switching element of the cylindrical valves.

FIG. 27 is a sectional view along the line B -B in FIG. 26.

FIG. 28 is a sectional view along line C-C in FIG. 26.

FIG. 29 is a view of the variant of the fluid module interchangeable with the switching element of the cylindrical valves driven by the center.

Figure 30 is a view of a variant of the double cylinder block in one piece of the variant of the fluid module interchangeable with the switching element of the cylindrical valves driven by the center. FIG. 31 is a view of a variant of the fluid module interchangeable with the switching element of the cylindrical valves driven by one side and the inlet and outlet ports of which are fixed to the cylinder blocks.

FIG. 32 is a side view of FIG. 31.

- Figure 33 is a sectional view along line B-B of Figure 32.

FIG. 34 is a perspective view of the switching element of the cylindrical valves of the variant of the interchangeable fluid module of FIG. 31.

According to Figures 1 to 5 and 11 and 13, the interchangeable fluid module (1) consists of two cylinder blocks (2,2 '), preferably identical, assembled in opposition to the assembly line (34) parallel to the axes displacement piston (35,35 ') and a valve switching element (4) positioned between the two cylinder blocks (2,2'). The cylinder blocks (2,2 ') include openings (70', 70 ”) on their rear face so as to form an opening (70), when joined, allowing access to the switching element valves (4) from the outside. Each cylinder block (2.2 ’) each has an opening

(80.80 ’) on its back so as to allow access to the pistons (3.3’) from the outside. The axis of rotation (97) of the rotor (14) is preferably located between the axes of movement of the pistons (35.35 ’) and equidistant from each of them. The axis of rotation (97) of the rotor (14) is preferably perpendicular to the axes of movement of the pistons (35.35 ’) and parallel to the switching axis (7).

Figure 3 shows the pumping mechanism (5) coupled to a motor (30). The pumping axes (6,6 ') and the switching axis (7) actuate the two pistons (3,3') and the valve switching element (4) of the interchangeable fluid module (1) respectively. On the face 12, the pumping axes (6,6 ') are fixed on pumping carriages (15,15') guided by linear bearings (24, 24 ', 24 ”, 24'”). Each carriage (15,15 ') is actuated simultaneously but independently of one another during the angular displacement of the rotor (14). The switching axis (7) of the valves is fixed on the valve carriage (16) also guided by linear bearings (25, 25 '). Figure 4 shows the pumping mechanism with the interchangeable fluid module (1) inserted. The inlet port (8) is preferably located on the cylinder block (2), and the outlet port (9) on the cylinder block (2 ').

According to Figures 5, 6, 11 and 13, the two pistons (3,3 ') receive sealing elements, preferably O-rings (10, 10', 10 ”, 10 '”) and are inserted in the pumping chambers (11,11 ') opposite, preferably cylindrical, of the cylinder blocks (2,2') parallel and eccentric with respect to the axis of rotation (97) of the rotor (14). The port (13) of the pumping chamber (11) communicates with the opening (71), and the port (13 ’) of the pumping chamber (11’) communicates with the opening (71 ’). The inlet port (8) communicates with the valve inlet port (8 ’) and the outlet port (9) communicates with the valve outlet port (9’). The inlet port (8) and the outlet port (9) are located between the pumping chambers (11.11 ’).

The valve seals (12,12 ') are inserted on each side of the valve switching element (4). Each shape joint (12,12 ') preferably comprises three contours respectively (60,61,62) and (60', 61 ', 62') and of which these can be linked together during the molding of the shape joints ( 12.12 ') in single joints. It is also possible to make the shape joints (12,12 ') by the use of Orings joints not interconnected. The shape seal (12) does not have the same geometry as the seal (12 ') in order to allow on the one hand the simultaneous opening of the ports (13,13') of the pumping chambers (11,11 ') to the outlet port (9) and the alternative opening of the ports (13,13 ') of the pumping chambers (11,11') to the inlet port (8). The contours (60, 60 ') and (61, 6) respectively surround the inlet (50, 50 ') and outlet (51, 5) transfer chambers. The shape seals (62, 62 ') provide sealing with the outside. Figures 5 and 6 illustrate among other things the valve switching element (4) which preferably has the geometry of a rectangular block. The port (22) allows the connection between the inlet transfer chambers (50,50 '), and the port 23 allows the connection between the outlet transfer chambers (51,51'). The inlet transfer chambers (50.50 ') are thus always connected to the inlet port (8). The outlet transfer chambers (51, 51 ') are thus always connected to the outlet port (9).

The rotor (14) moves the valve switching element back and forth and thus connects the port (13) of the pumping chamber (11) with the inlet transfer chamber (50) for filling or with the outlet transfer chamber (51) for emptying, and the port (13 ') of the pumping chamber (11') with the inlet transfer chamber (50 ') for filling or with the outlet transfer chamber (51 ') for emptying. These connections are synchronized with the movement of the pistons. The inlet transfer chamber (50) is preferably arranged to be on either side of the outlet transfer chamber (51).

According to Figures 3, 9 and 12, the rotor (14) is coupled to the axis of the motor (30) and held by ball bearings (19,19 ') on the base (20) of the pumping mechanism (5). A guide element (17), preferably a ball bearing, placed on the valve drive axis (18) mounted eccentrically on the rotor (14), and housed in a groove (33), exerts an alternating linear drive. of the valve carriage (16) guided by linear bearings

(25.25 '). According to FIGS. 9, 10 and 12, a cam groove (36) placed axially in the rotor (14) makes it possible to move the pumping axes by rolling guide elements (2l, 2r, 2l ”, 2r”). , preferably ball bearings, inside the cam groove (36) and thus to exert a reciprocating linear movement on the pumping carriages (15,15 ') guided by linear guides (24, 24', 24 ”, 24 '”). The movement of the valve carriage (16) is carried out with the linear guide elements (25,25 ').

Figure 11 shows the coupling of the pump axes (6.6 ’) in the pistons (3.3’) and the switching axis (7) in the valve switching element (4). This sectional view also illustrates the ports around the valve switching element (4), i.e. the connection between the pumping chambers (11.11 ') with the ports (13.13') and the port. inlet (8) with the valve inlet port (8 '), and the outlet port (9) with the valve outlet port (9').

Figure 13 shows the profile of the cam groove (36) in the rotor (14). The two pistons (3.3 ') perform their respective independent linear movement in opposition, i.e. 180 ° from each other, via the pumping axes (6.6'), along the profile of the cam groove (36). This profile is broken down into 6 segments (26, 27, 28, 29, 30, 31) designed for clockwise rotation of the rotor (14). The cam groove (36) can also be profiled for rotation of the rotor (14) counterclockwise. The segment (26) corresponds to the initial emptying phase with reduced displacement of a piston, preferably corresponding to half of the nominal flow rate. The segment (27) corresponds to the emptying phase at nominal displacement of a piston, corresponding to the nominal flow. The segment (28) corresponds to the final phase of emptying with reduced displacement of a piston, preferably corresponding to half of the nominal flow rate. The segment (29) corresponds to the switching phase of the valves which closes the connection between the port of a pumping chamber and the respective outlet transfer chamber and then links the transfer chamber inlet with the port of the pumping chamber, and without movement of the piston. The segment (30) corresponds to the filling phase of a pumping chamber. The segment (31) corresponds to the switching phase of the valves which closes the connection between the port of a pumping chamber and the respective inlet transfer chamber and then links the outlet transfer chamber with the port of the handling chamber. pumping, and without movement of the piston. The segments (26, 27, 28) for emptying the chambers are dimensioned in order to produce a linear displacement of the pistons (3.3 ′) proportional to the angle of rotation of the rotor (14). The segments (26) and (28) placed in opposition, make it possible to obtain a continuous linear flow rate, because the piston starting its emptying phase on the segment (26) simultaneously delivers with the piston ending its emptying phase on the segment ( 28).

According to Figure 14, the ball bearing (17), housed in the groove (33) of the valve carriage (16), allows the reciprocating linear displacement of the latter in order to effect the switching of the valves by driving the element of switching valves (4) placed between the cylinder blocks (2, 2 ') and connected to the valve carriage (16) via the switching axis (7). Figure 15 shows two superimposed graphs illustrating the synchronization of the different pump operating sequences according to the movement of the two pistons along the segments of the cam (top graph) and the angular movement of the valve drive axis ( 18) producing the movement of the switching elements of the valves (4) as well as the states of the valves (bottom graph). The vertical line (32) corresponds to the angular position of the pump in FIG. 12. The curve of "chamber 1" relates to the pumping axis (6) corresponding to the pumping chamber (11) and the curves of the "Chamber 2" relates to the pumping axis (6 ') corresponding to the pumping chamber (11'). Pumping segments (26,27,28,29,30,31) of the cam groove (36) shown in FIG. 12 are indicated by braces on the curve of chamber 1, which are also valid for chamber 2.

The curve (100) corresponds to the cumulative displacement of the two pistons, on the portions during which the outlet valves are open for each of the chambers, as a function of the angular displacement of the rotor. It can be seen that this curve (100) is a continuous straight line without interruption corresponding to a continuous, uninterrupted and regular output flow from the pump.

In the lower graph, the switching of the valves is indicated according to the pumping segments of chambers 1 and 2.

According to the preceding descriptions, the controlled displacements of the pistons (3,3 ′) and of the switching element of the valves (4) preferably take place alternately and parallel to each other while being synchronized with the angular displacement of the rotor (14).

The cam groove (36) can be dimensioned to produce any form of output and input flow signal.

Figures 16 to 20 show the version of the interchangeable fluid module (101) with parts produced by plastic injection. The fixing between the cylinder blocks is ensured by clips (37, 37 ', 37 ”, 37'”). Access to the pistons and pumping chambers is protected by the protective elements (38, 38 ') enabling the pumping chamber to be covered by one cylinder block with the other cylinder block and vice versa. An arrow (39) fixed on the valve switching element identifies the inlet (8) and the outlet (9) of the pump. The insertion and orientation of the pistons (103,103 ') in the pumping chambers (11,11') is ensured by the angular positioning pins (42,42 ') housed respectively in the grooves (43,43') located on the cylinder blocks (102,102 '). Figure 19 illustrates the inlet chamfers (40, 40 ') on the pistons (103,103') to allow the insertion of the pumping axes (6,6 ') whatever the position of the pistons (103,103').

FIG. 20 illustrates the inlet chamfers (41) around the opening (44) on the valve switching element (104) allowing the insertion of the switching pin (7) whatever its position.

The inlet (8) and outlet (9) ports can be placed on the front or sides of the cylinder blocks (2,2 ’, 102, 102’). In a variant not illustrated, the valve seals (12,12 ') can be housed in the cylinder blocks (2, 2', 102, 102 '), in contact with the valve switching element (4, 104 ) In the variant illustrated in FIGS. 21 to 30, the interchangeable fluid module (201) has a valve switching element (204) of preferably cylindrical section. This valve switching element (204) slides in a housing formed by two openings 271, 271 ’) preferably contiguous in the cylinder blocks (202, 202’) parallel to the pumping chambers (211, 211 ’). The valve switching element (204) is preferably driven at its ends by preferably two opposite elements (not shown) fixed on the valve carriage (16).

The valves are switched by aligning the port (213) of the pumping chamber with the inlet (250) or outlet (251) transfer chambers, and the port (213 ') of the pumping with the inlet (250 ') or outlet (251') transfer chambers. The port (213) of the pumping chamber (211) communicates with the opening (271), and the port (213 ') of the pumping chamber (211') communicates with the opening (271 '). The peripheral sealing of the inlet (250, 250 ') and outlet (251, 251') transfer chambers is preferably ensured by O-rings (274, 274 ', 274 ”) and (275, 275', 275 ”). A seal (280) located between and around the openings (271,271 ') provides internal sealing between the cylinder blocks (202,202'). The input communication port (222) of the valve switching element (204) communicates with the input transfer chambers (250, 250 ') and the input port (208) of the pump. The output communication port (223) of the valve switching element (204) communicates with the output transfer chambers (251, 251 ') and the output port (209) of the pump. The inlet port (208) and the outlet port (209) are located between the pumping chambers

(211,211 ’).

FIG. 29 shows a variant of the interchangeable fluid module (201) having a valve switching element (204) of cylindrical section which is driven by the medium. An opening (240) located between the cylinder blocks (220,220 ’) allows access to the valve switching element (204) through the drive element (not shown).

FIG. 30 shows a variant of the interchangeable fluid module (201) having a switching element for the valves (204) of cylindrical section where the cylinder blocks are made in one piece (230).

According to Figures 31 to 34, the inlet (308) and outlet (309) ports are placed on the cylinder blocks (302,302 '). The inlet port (308) is preferably of wide section in order to be able to suck viscous fluids at high flow rate and is fixed to the end of the opening (371) of the block. cylinder (302 '). The outlet port (309) is preferably fixed on one face of the cylinder block (302) and perpendicular to the movement of the valve element (304).

The input communication port (322) of the valve switching element (304) communicates with the input transfer chambers (350, 350 ’) and the input port (308) of the pump. The output communication port (323) of the valve switching element (304) communicates with the output transfer chambers (351, 351 ’) and the output port (309) of the pump.

The valve switching element (304) preferably comprises on one of its sides an opening (344) receiving the switching axis (7). In a variant not illustrated, conduits preferably in connection with the inlet and outlet ports can be placed in the cylinder blocks and adapted so as to connect pressure measuring elements such as, for example, membranes or any other component reacting to the pressure variation.

In a variant not illustrated, the valve element may be wholly or partly rounded so as to pivot or rotate during the movement of the pistons by means of the rotor (14).

The assembly of the cylinder blocks can preferably be carried out by clips, screws, conical shapes, by welding or recasting.

The sealing between the movable and fixed parts is preferably carried out using elastomers, O-rings, shaped seals, overmolded seals or any other sealing element. However, it is possible to produce the pump preferably without seals by adjustment between parts. The elements constituting the interchangeable fluid module (1,101, 201, 301) are preferably made of single-use plastic, preferably by injection or by machining. The pump can be sterilized for the distribution of food, medicine or body fluids for example. The choice of materials is not limited to plastics, however. In a variant not illustrated, the switching element of the valves can be in the form of a rotary disc, preferably axially and in direct engagement with the rotor.

The invention can be incorporated into devices intended for pumping chemical, pharmaceutical, petroleum or any other kind of fluid. It can also be integrated into medical devices intended to inject or suck fluids into / from the body. These devices can combine several pumps in parallel or in series with external elements such as valves, connectors or any other component allowing multiple fluid circuits to be produced. The invention lends itself particularly well to an operation requiring the diffusion or the mixing of fluids under pressure and high pressure precisely. It can also be used in systems requiring dynamic flow control manually or automatically such as medical pumps / injectors and dosing / filling systems.

The pump can also be used as an air compressor and made of durable materials such as steel and ceramics for devices requiring intensive operation with a long service life.

Although the invention is described according to an embodiment, there are other variants which are not presented. The scope of the invention is therefore not limited to this embodiment described above.

Claims

1. A pump with interchangeable fluid module (1) comprising at least two pistons (3.3 ') placed in two opposite pumping chambers (11.11') located respectively in two cylinder blocks (2, 2 ', 202, 202 ', 302, 302') held together parallel to the axes of movement of the pistons (35.35 ') and having at least one inlet port (8,208,308) through which the fluid is sucked into the pumping chambers (11, 11 ', 211, 211', 311, 311 ') during the piston filling movement, then expelled from the pumping chambers during the piston emptying movement towards at least one outlet port (9,209, 309) characterized by an element switching valves (4,204,304) including inlet (50, 50 ', 250, 250', 350, 350 ') and outlet transfer chambers

(51.51 ’, 251.251’, 351.351 ’) of the communicating pump by means of the input (22,222,322) and output (23,223,323) communication ports located in the valve switching element (4,204,304).

2. Pump according to claim 1, in which the valve switching element (4) is placed between the cylinder blocks (2, 2 ’, 202, 202’) parallel to the pistons (3,3 ’).

3. Pump according to claim 1, the axis of linear displacement of the valve switching element (4,204,304) is parallel to the pistons (3,3 ’).

4. Pump according to claim 1, whose inlet (8,208,308) and outlet (9,209, 309) ports are located between pumping chambers (11, 11 ', 211, 211', 311, 311 ').

5. Pump according to claim 1, the output flow is preferably continuous without pulsation.

6. Pump according to claim 1, the rotor (14) of which comprises a cam groove (36) actuating displacement of the pistons (3.3 ’).

7. Pump according to claim 6, the profile of the cam groove (36) is composed of six segments.

8. Pump according to claim 1, in which the linear displacement of the pistons (3.3 ’) is independent of one another.

9. Pump according to claim 1, the parts of the interchangeable fluid module (1) are plastic and disposable.

10. Pump according to claim 1, the sum of the reduced flow rates of the drain start segments (26) and end of drain (28) corresponds to the nominal flow rate of the drain segment (27).

11. Pump according to claim 1, in which the mechanism for driving the pistons (3,3 ′) and the valve switching element (4,204,304) is external to the interchangeable fluid module (1).

12. Pump according to claim 1, in which the two pumping chambers (11, 1 G, 211,211 ', 311,311') simultaneously expel towards the outlet port (9,209,309) on a segment of the cam groove (36) of the rotor ( 14). 13. Pump according to claim 1, the sealing between the movable and fixed parts of the interchangeable fluid module (1) is carried out with at least one elastomer.

14. Pump according to claim 1, the valve switching element (204,304) is cylindrical.

15. Pump according to claim 1, in which the inlet port (208, 308) and / or the outlet port (209, 309) are placed on the valve switching element (204, 304).

16. Pump according to claim 1, in which the inlet port (8) and / or the outlet port (9, 309) are placed on the cylinder blocks (2, 2 ’, 302).

17. Pump according to claim 1, whose cylinder blocks are made in one piece

(230).