PERISTALTIC PUMP

Abstract

A peristaltic pump including a support surface including an interior face, a drive device for driving the rotation of rollers so as to compress the tube at least at one point on the interior face of the support surface, this drive device being a direct-drive device.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is based on and claims priority under 35 U.S.C. § 119 to European Patent Application No. 23175131.4, filed on May 24, 2023, in the European Patent Office, the disclosure of which is incorporated by reference herein in its entirety.

BACKGROUND

Field

The technical field of the present disclosure is that of positive-displacement pumps and more particularly of deformable-tube peristaltic pumps.

Brief Description of Related Developments

Peristaltic pumps are well known and used in numerous technical fields, for example the chemical industry, the cosmetic industry, the oil industry, the agri-foodstuffs industry, and in medicine, particularly for conveying blood or other liquids administered as a drip, etc.

A peristaltic pump is made up of a supporting structure to which there is attached a motor the shaft of which drives the rotation of a cage containing a plurality of wiper wheels better known as rollers.

These rollers, which are free to rotate about their axis, successively squeeze a deformable tube until it is fully occluded.

The alternating pressure on and release of pressure from the walls of the deformable tube creates a negative pressure and suction effect so that a fluid trapped inside the deformable tube between the rollers is thus driven along the length of the tube.

A fluid pumped from one open end of the deformable tube, referred to as the intake or upstream end, is thus discharged at the other open end of the deformable tube, referred to as the discharge or downstream end.

A main advantage of this peristaltic pump is that the fluid thus displaced remains intact while it is being transferred because at no time is it in contact with the rollers, only with the internal wall of the deformable tube.

The peristaltic pump therefore constitutes a particularly clean pumping solution.

Conventionally, there are three distinct parts that can be discerned in a peristaltic pump, each having a determined function, and all of these functions together being required in order for the pump to work.

A first part consists of the peristaltic-pump motor, which comprises a motor shaft or spindle mounted so as to be able to rotate on two bearings spaced apart from one another within the motor body.

This motor provides a driving function.

The peristaltic pump is also provided with a reduction gear assembly which performs the function of “transmitting/gearing-down” the motor torque.

Finally, and as recalled above, a rotor with rollers performs a “pumping” function.

Correct operation of a peristaltic pump requires controlled and careful alignment of these three “functions”.

In particular, the two bearings of the motorized drive need to be precisely aligned with the bearing formed by the pump rotor.

However, it has been found that such alignment is generally difficult to achieve.

In order to overcome this difficulty, it is known practice to add components or to set up the pump in such a way as to be able to compensate for any alignment errors. Such peristaltic pumps nevertheless take longer and are more expensive to manufacture.

Moreover, it is found that such a pump of the prior art is typically designed for the one or few clearly defined applications for which it is envisioned, so that it has a predetermined reduction ratio.

In order to perform distinct operations it may therefore be necessary for the operator to have available peristaltic pumps that offer different reduction ratios so that these operations can be carried out correctly.

The management of such pumps presents a problem of cost and of storage.

There is therefore still a pressing need for a peristaltic pump of which the original design is able to overcome the above-mentioned disadvantages of the prior art.

SUMMARY

The present disclosure seeks to overcome the disadvantages of the prior art by proposing a peristaltic pump which is simple in its design and in its mode of operation, offering different reduction ratios in order to provide greater multifunctionality of use.

Another object of the present disclosure is for such a peristaltic pump to be particularly economical and able to be mass produced.

Yet another object of the present disclosure is for such a pump to be able to overcome the need for precise alignment between the drive and the rotor.

The present disclosure also relates to a preassembled subassembly comprising such a peristaltic pump and a deformable tube.

To this end, the disclosure relates to a peristaltic pump intended to operate with a deformable tube, this peristaltic pump comprising a support surface comprising an interior face, a drive device for driving the rotation of the rollers so as to compress said tube at least at one point on the interior face of said support surface, this drive device being a direct-drive device.

According to the disclosure:

• • said peristaltic pump comprises a central roller, positioned between said rollers and in contact therewith, said central roller forming a central point of contact for relaying the load applied to said at least one roller compressing said deformable tube against said interior face, said central roller having a longitudinal axis,
  • said peristaltic pump comprises a gearwheel support element which is pierced at its center and comprises pins on at least one of its faces to support peripheral gearwheels, a central gearwheel engaging with said peripheral gearwheels so as to drive same, the assembly forming a geared drive device for driving the rotation of said rollers so as to compress said tube at least at one point on the interior face of said support surface, and/or
  • said central roller comprises an orifice extending along its longitudinal axis and opening onto at least one of the lateral edges of said roller, said orifice having a female socket shape configured to be connected to the shaft of a motor for driving the rotation of said roller and, therefore, for driving the rotation of said rollers, this rotational driving of said rollers being what is known as friction drive, and
  • said peristaltic pump is thus configured to offer, using the same set of rollers, at least two different reduction ratios when it has two of said devices for driving the rollers, and at least three different reduction ratios when it comprises all three devices for driving the rollers.

Advantageously, such a peristaltic pump tolerates a broad range of applications thanks to its different reduction ratios.

It is therefore multifunctional, economical and particularly simple to operate.

Having a cage formed by two separators, it is reversible with respect to a shaft of a motor, or motor torque, so as to offer different reduction ratios.

Advantageously, the one same peristaltic pump thus offers a number of ways of driving the rotation of its rollers, offering up to four drive modes:

• • direct drive,
  • geared drive,
  • friction drive, and
  • hybrid drive.

Moreover and advantageously, the original design of the rotor of this peristaltic pump and the freedom of placement thereof, particularly as regards the hubs of the rollers, makes it possible to overcome the need for precise alignment between the motor axis and the rotor.

As a preference, this central roller is wedged between said rollers.

According to one aspect of this peristaltic pump, with said peristaltic pump comprising a device for the geared driving of the rollers and with said central roller comprising an orifice extending along its longitudinal axis and opening onto at least one of its lateral edges, said central gearwheel is removable so as to allow just the central roller to be driven directly by the shaft of a motor so as to drive the rotation of said rollers by friction, said peristaltic pump thus offering a third different geared-down reduction ratio.

According to another aspect of this peristaltic pump, it comprises a device for the geared driving of the rollers, and one lateral edge, or end, of said central roller is inserted into the central hole in said gearwheel support element in order to support said central roller.

According to yet another aspect of this peristaltic pump, comprising a device for the geared driving of the rollers and said gearwheel support element comprising pins for supporting said rollers and thus forming a separator, this peristaltic pump comprises a single separator and is said to be a single-separator pump, the central hole in this separator determining a female socket that complements the male end shape of the shaft of a motor so that these can be assembled by fitting the one into the other so as to allow direct rotational drive of said rollers.

As a preference, this central roller is configured so that it stays in position between said rollers.

By way of example, with said central roller having a longitudinal dimension greater than that of the rollers, each of its lateral edges, or ends, has a flared shape or a boss to prevent movement of said central roller along the main axis about which said rollers are rotationally driven by said geared driving device.

Alternatively, with said gearwheel support element also comprising pins for supporting said rollers and thus forming a first separator, this peristaltic pump comprises a second separator pierced at its center and comprising pins on at least one of its faces, said first and second separators defining a cage to receive and support at least said rollers and the central roller, said second separator comprising a central hole supporting a pinion intended to be driven directly by a shaft of a motor in order to drive the rotation of said rollers, or this central hole in said second separator defining a female socket that complements the male end shape of the shaft of a motor so that these can be assembled by fitting the one into the other so as to allow direct rotational drive of said rollers.

This female socket shaped is for example selected from the group comprising square, hexagonal, splined, flatted cylindrical, etc.

Purely by way of illustration, this externally-toothed gearwheel or pinion is assembled with the second separator by clip-fastening or else by elastic deformation thereof, inside the central hole in this separator.

As a preference, this peristaltic pump comprises an externally-toothed gearwheel or pinion supported by a separator distinct from said gearwheel support element, an assembly element projecting from the opposite face of this externally-toothed gearwheel from the face that is intended to face toward the motor, said assembly element being configured to allow assembly of the externally-toothed gearwheel and of said central roller, a central opening configured to house one end of said central roller and allow it to be assembled with said central roller, said peristaltic pump additionally comprising an individual component of which the periphery or external surface defines a shape, such as a square or hexagonal shape, intended to collaborate with an orifice of complementary shape belonging to a separator of said peristaltic pump, said individual component having a central orifice configured to allow the passage of the end of said central roller.

According to yet another aspect of this peristaltic pump, it comprises at least one separator pierced at its center and comprising at least six pins.

These pins may be positioned on the one same face of the separator or distributed between opposite faces of this separator.

By way of purely illustrative example, with this peristaltic pump comprising n rollers, said gearwheel support element comprising pins for supporting said rollers and thus forming a separator, said or at least one of said separators comprises two opposite faces, at least one of said faces receiving at least two sets of n pins, the n pins of a first set being distributed on a circle of diameter D and the n pins of another set being distributed on a circle of diameter G so as to define two distinct reduction ratios for said peristaltic pump using corresponding rollers.

Of course, these two sets of pins could be provided on the one same face of this separator.

This separator may be a disk pierced at its center, but it could adopt any other suitable shape such as square, rectangular, triangular, etc.

Alternatively, with said pump comprising n rollers, said gearwheel support element comprising pins for supporting said rollers and thus forming a separator, said or at least one of said separators comprises at least two sets of n holes distributed on corresponding circles of different diameters and a single set of n spindles so as to form, with each set of holes, pins for supporting corresponding rollers, said sets of n holes defining distinct reduction ratios for said peristaltic pump.

According to another aspect of this peristaltic pump, the rotor of this pump comprises between three (3) and five (5) rollers.

According to yet another aspect of this peristaltic pump, it comprises a single separator, said pump being said to be a single-separator pump.

Such an aspect advantageously makes it possible to simplify the assembly of the peristaltic pump while at the same time reducing the cost thereof.

According to yet another aspect of this peristaltic pump, it is configured in such a way that this secondary, so-called friction, driving of said rollers by said central roller combines with the geared-driving of the rotation of said rollers, the drive thus formed being said to be hybrid.

As a preference, with this peristaltic pump comprising a geared-drive device for driving the rollers and said central roller comprising an orifice extending along its longitudinal axis and opening onto at least one of its lateral edges, said central gearwheel has a hole placed facing the orifice of said central roller, the hole in said gearwheel and the orifice of said roller having the same female socket shape that complements the male shape of the shaft of a motor so that these can be assembled by fitting the one into the other so as to allow rotational driving of said rollers and of said central roller.

Alternatively, with said peristaltic pump comprising a device for the geared driving of the rollers and said central roller comprising an orifice extending along its longitudinal axis and opening onto at least one of its lateral edges, said central gearwheel comprises an assembly element projecting from its opposite face from the one that is intended to face toward the motor, said assembly element being configured for assembling this central gearwheel with said central roller.

According to yet another aspect of this peristaltic pump, and in a mode of driving of said peristaltic pump said to be a hybrid mode, this central roller is connected to the motor shaft for driving the rotation of this central roller, and, therefore, of said rollers with which it is in contact, this secondary drive being in addition to the geared or direct driving of the rotation of said rollers.

Such an aspect also advantageously makes it possible to avoid a potential phenomenon of twisting of the rollers when they are driven in their rotation by the rotor and when at least one of these rollers is compressing the tube against the interior face of the support surface of the peristaltic pump.

By way of illustration, with the drive device being a geared drive device comprising an epicyclic geartrain, the sun gear comprises:

• • an assembly element having a projection on its opposite face from the one intended to face toward the motor, said assembly element being configured for assembling said sun gear with said central roller, or
  • has a central opening configured to receive one end of said central roller and allow it to be assembled with said central roller.

Alternatively, with said drive device being a direct-drive device, this peristaltic pump comprises an externally-toothed gearwheel, an assembly element projecting from its opposite face from the one that is intended to face toward the motor, said assembly element being configured to allow assembly of said gearwheel and of said central roller, or comprises an externally-toothed gearwheel having a central opening configured to house one end of said central roller and allow it to be assembled with said central roller, said peristaltic pump additionally comprising an individual component of which the periphery or external surface defines a shape, such as a square or hexagonal shape, intended to collaborate with an orifice of complementary shape belonging to a separator of said peristaltic pump, said individual component having a central orifice configured to allow the passage of the end of said central roller.

According to yet another aspect of this peristaltic pump, said projecting assembly element is configured to allow it to be assembled by clip-fastening, or else elastic deformation thereof, in a recess in the end of said central roller.

Alternatively, with the opening in said sun gear or in said externally-toothed gearwheel having an oblong shape, one end of said central roller has an assembly face of complementing shape to allow assembly by fitting said central roller into said sun gear or said gearwheel.

According to yet another aspect of this peristaltic pump, the components that make up said pump are made of plastic, the body of the peristaltic pump, also known as the pump casing, being made as two half-casings assembled with one another, said half-casings being identical.

Advantageously, the components that make up said pump are made of plastic and are identical in the case of those components that are common to said geared-drive and direct-drive pumps, namely in respect of those components that are common to the two peristaltic pumps covered by the present disclosure.

According to yet another aspect of this peristaltic pump, comprising at least one rotor, said peristaltic pump comprises an electric motor driving the rotation of said rotor or rotors, this electric motor being selected from a stepper motor, a DC motor or an AC motor, possibly including an epicyclic reduction geartrain.

According to yet another aspect of this peristaltic pump, it comprises a casing comprising a casing first part and a casing second part, said casing first part comprising a hole for the passage of the motor shaft, an interior face and an exterior face, part of said exterior face of said casing first part defining, at said hole, a housing or support to house an entirely open end of the motor body, and the peristaltic pump comprising at least one means for fixing this motor body in this housing or support. Thus, the motor comprises a motor body containing a front bearing and a rear bearing, a shaft mounted so as to rotate on these two bearings, this shaft projecting from a front end of the motor body. This front end of the motor body is open.

Advantageously, the motorized drive for the peristaltic pump can therefore be fixed directly on the pump body, making this pump simpler and more economical.

As a preference, this support projects from said exterior face of the casing first part, being centered on this hole.

Advantageously, as the motor body is tubular, this support forms a flange or two concentric annular lips to receive the open end of the motor body.

Alternatively, the support forms a tubular portion in which said pump body is intended to be received.

By way of example, said fixing means consists of threaded holes to receive fixings of the motor body.

The present disclosure also relates to a preassembled subassembly comprising a peristaltic pump as described hereinabove and a peristaltic pump deformable tube.

The present disclosure further relates to such a preassembled subassembly comprising at least two sets of different rollers, making it possible to change the reduction ratios of said peristaltic pump.

BRIEF DESCRIPTION OF THE DRAWINGS

Other advantages, aims and particular features of the present disclosure will become apparent from the following description, which is provided for explanatory purposes and is non-limiting and in which reference is made to the accompanying drawings, in which:

FIG. 1

FIG. 1 is an exploded view of a peristaltic pump according to a first aspect of the present disclosure, said pump comprising a device for the geared driving of the rotor;

FIG. 2

FIG. 2 is a view in cross section of the peristaltic pump of FIG. 1, showing the layout of the rollers and of the central roller;

FIG. 3

FIG. 3 is an exploded view of a peristaltic pump according to a second aspect of the present disclosure, said pump comprising a device for the direct driving of the rotor;

FIG. 4

FIG. 4 is a view in cross section of the peristaltic pump of FIG. 3, showing the layout of the rollers and of the central roller;

FIG. 5

FIG. 5 is a schematic depiction of the separator of the peristaltic pump illustrated in FIG. 3;

FIG. 6

FIG. 6 is a view of the rear face, intended to face toward the motorized driver of the pump, of the separator illustrated in FIG. 5;

FIG. 7

FIG. 7 is a schematic and exploded view of a peristaltic pump according to a third aspect of the present disclosure, said pump being said to have hybrid drive;

FIG. 8

FIG. 8 is a schematic depiction of the central roller, of the pierced gearwheel and of the ring of the peristaltic pump illustrated in FIG. 7;

FIG. 9

FIG. 9 is a schematic depiction of a peristaltic pump according to another aspect of the present disclosure, said pump comprising a geared drive device and a direct drive device for driving the rollers, the rollers here being driven in their rotation directly;

FIG. 10

FIG. 10 shows the peristaltic pump illustrated in FIG. 9, in which the rotational driving of the rollers is performed by the geared drive device of this pump alone;

FIG. 11

FIG. 11 shows the peristaltic pump illustrated in FIG. 9, in which the rotational driving of the rollers is performed by a friction drive, the central gearwheel of the geared drive device having been removed;

FIG. 12

FIG. 12 shows the peristaltic pump illustrated in FIG. 9, in which the rotational driving of the rollers is performed by a drive of hybrid drive type, combining friction driving and geared driving of the rotor.

DETAILED DESCRIPTION

The drawings and the description below contain, for the most part, elements of a determinate nature. They will therefore not only serve to better understand the present disclosure but also contribute to the definition thereof, where appropriate.

Firstly, it will be noted that the figures are not to scale.

FIGS. 1 and 2 schematically illustrate a peristaltic pump 10 according to a first aspect of the present disclosure.

This peristaltic pump 10, which comprises a geared device for driving the rotor, is said to be a single-separator pump, which is to say it comprises a single separator.

It comprises a casing 11 which is formed by two identical casing-body parts assembled with one another to determine a space in which to house a support surface 12. These casing-body parts 11 are obtained here by molding in a plastics material.

The pump also comprises a pump body tube (not depicted) for transporting liquid. This pump body tube is made from an elastomeric material.

The peristaltic pump 10 comprises a rotor bearing three rollers 13 that are free to rotate, the rotor being driven in rotation by the geared driving device which here comprises an epicyclic reduction motor 18. The rollers 13 borne by pins 14 of the separator 15 are uniformly distributed at the periphery of the rotor, each roller 13 thus being angularly spaced from its neighbor by an angle of 120°.

The interior face of the support surface 12 forms a support against which the pump body tube is squeezed by the rollers in order to occlude this tube and displace the liquid contained therein.

This peristaltic pump 10 additionally comprises a central roller 16, positioned between the rollers 13 and in contact therewith, this central roller forming a central point of contact for relaying the load applied to said at least one roller 13 compressing said deformable tube against said interior face, at each instant.

The ends of this central roller 16 have bosses 17 for holding it in position and automatically centering it on the rollers 13.

All of the components of this peristaltic pump, with the exception of its motorized drive, are made of plastic. This peristaltic pump is therefore particularly economical while at the same time being particularly reliable.

FIGS. 3 and 4 schematically illustrate a peristaltic pump 20 according to a second aspect of the present disclosure.

Those elements of the peristaltic pump 20 illustrated in FIGS. 3 and 4 that bear the same references as those of the peristaltic pump 10 illustrated in FIGS. 1 and 2 represent the same objects, which will not be described again below.

This peristaltic pump 20, said to be a single-separator pump, differs from the pump depicted in FIGS. 1 and 2 in that it comprises a direct-drive device.

FIGS. 7 and 8 show an exploded view of a peristaltic pump 30 according to a third aspect, this peristaltic pump 30 being said to have hybrid drive.

Those elements of the peristaltic pump 30 illustrated in FIGS. 7 and 8 that bear the same references as those of the peristaltic pump 10 illustrated in FIGS. 1 and 2 represent the same objects, which will not be described again below.

In addition to having a main drive of the rollers 13 that is provided by the direct drive device of the peristaltic pump, the rollers have a secondary drive achieved by connecting the motor shaft to one end of the central roller 16.

To do that, the peristaltic pump 30 comprises an externally-toothed gearwheel 31 comprising an oblong central opening to accept an end, of complementing shape, of the central roller 16 and allow the one to be assembled with the other.

The peristaltic pump 30 additionally comprises a ring 32 of which the periphery or external surface defines a shape, in this instance hexagonal, intended to engage with an orifice of complementing shape placed in the separator 15 of the peristaltic pump, this ring 32 having a central orifice configured to allow the end of the central roller 16 to pass.

The end of the motor shaft is introduced directly into a longitudinal opening of the central roller opening at the tip 33 of the end of the roller so as to connect this motor shaft and the central roller 16.

Not only is the central roller 16 immobilized axially by its connection to the motor shaft, but also, the driving of this central roller 16 by the motor shaft generates an additional friction driving of the rollers 13 that are in contact with this central roller.

It may be noted that this dual driving of the rollers 13 prevents any possible twisting of these rollers during operation of the peristaltic pump 30.

FIGS. 9 to 12 show the various drive modes for driving a peristaltic pump 40 according to another aspect of the present disclosure.

This one same peristaltic pump 40 advantageously offers a plurality of reduction ratios, while having up to four drive modes:

• • direct drive (FIG. 9): reduction ratio equal to 1,
  • geared drive (FIG. 10): reduction ratio here equal to 7,
  • friction drive (FIG. 11): reduction ratio here equal to 8, and
  • hybrid drive (FIG. 12): reduction ratio here equal to 7.

The body of this peristaltic pump 40 is formed of two identical half-casings made of plastic and assembled with one another. Each of these half-casings thus has a central orifice for the insertion of the shaft of a motor 41.

Most of the components of this peristaltic pump 40 are likewise made of plastic, making the cost of production of this pump very economical.

The pump comprises two separators 42, 43 supporting its rollers 44 and its central roller 16

Advantageously, the separators 42, 43 are likewise identical and on one of their opposite faces have pins to support the peripheral gearwheels of the geared-drive device.

In addition, with this peristaltic pump comprising three rollers 44, each separator 42, 43 comprises two sets of three (3) holes distributed on corresponding circles of different diameters, and one set of three (3) spindles 45 to form, with each set of holes, supports for supporting corresponding rollers 44.

By merely changing these rollers 44 having a first diameter D for other rollers having a second diameter D′, the present peristaltic pump offers new reduction ratios for compressing the tube 46 at least at one point on the interior face of the support surface of this peristaltic pump 40.

A separator 42 supports a pinion 47 for the direct-driving of the rotation of the rollers. Alternatively, the central hole in this separator 42 could comprise a female socket shape that complements the male end shape of the shaft of the motor 41 so that these can be assembled by fitting the complementing shapes one inside the other to allow direct drive of the rotation of said rollers 44.

Claims

1. A peristaltic pump intended to operate with a deformable tube, said peristaltic pump comprising a support surface comprising an interior face, a drive device for driving the rotation of the rollers so as to compress said tube at least at one point on the interior face of said support surface, this drive device being a direct-drive device, characterized in that said peristaltic pump comprises a central roller, positioned between said rollers and in contact therewith, said central roller forming a central point of contact for relaying the load applied to said at least one roller compressing said deformable tube against said interior face, said central roller having a longitudinal axis,said peristaltic pump comprises a gearwheel support element which is pierced at its center and comprises pins on at least one of its faces to support peripheral gearwheels, a central gearwheel engaging with said peripheral gearwheels so as to drive same, the assembly forming a geared drive device for driving the rotation of said rollers so as to compress said tube at least at one point on the interior face of said support surface, and/orsaid central roller comprises an orifice extending along its longitudinal axis and opening onto at least one of the lateral edges of said roller, said orifice having a female socket shape configured to be connected to the shaft of a motor for driving the rotation of said roller and, therefore, for driving the rotation of said rollers, this rotational driving of said rollers being what is known as friction drive, andsaid peristaltic pump is thus configured to offer, using the same set of rollers, at least two different reduction ratios when it has two of said devices for driving the rollers, and at least three different reduction ratios when it comprises all three devices for driving the rollers.

2. The peristaltic pump according to claim 1, characterized in that, with said peristaltic pump comprising a device for the geared driving of the rollers and with said central roller comprising an orifice extending along its longitudinal axis and opening onto at least one of its lateral edges, said central gearwheel is removable so as to allow just the central roller to be driven directly by the shaft of a motor so as to drive the rotation of said rollers by friction, said peristaltic pump thus offering a third different geared-down reduction ratio.

3. The peristaltic pump according to claim 1, characterized in that, with said peristaltic pump comprising a device for the geared driving of the rollers, one lateral edge, or end, of said central roller is inserted into the central hole in said gearwheel support element in order to support said central roller.

4. The peristaltic pump according to claim 1, characterized in that, with said peristaltic pump comprising a device for the geared driving of the rollers and with said gearwheel support element comprising pins for supporting said rollers and thus forming a separator, said peristaltic pump comprises a single separator and is said to be a single-separator pump, the central hole in this separator determining a female socket that complements the male end shape of the shaft of a motor so that these can be assembled by fitting the one into the other so as to allow direct rotational drive of said rollers.

5. The peristaltic pump according to claim 4, characterized in that said central roller is configured to maintain its position between said rollers.

6. The peristaltic pump according to claim 5, characterized in that, with said central roller having a longitudinal dimension greater than that of the rollers, each of its lateral edges, or ends, has a flared shape or a boss to prevent movement of said central roller along the main axis about which said rollers are rotationally driven by said geared driving device.

7. The peristaltic pump according to Claims claim 1, characterized in that, with said gearwheel support element also comprising pins for supporting said rollers and thus forming a first separator, it comprises a second separator pierced at its center and comprising pins on at least one of its faces, said first and second separators defining a cage to receive and support at least said rollers and the central roller, said second separator comprising a central hole supporting a pinion intended to be driven directly by a shaft of a motor in order to drive the rotation of said rollers, or this central hole in said second separator defining a female socket that complements the male end shape of the shaft of a motor so that these can be assembled by fitting the one into the other so as to allow direct rotational drive of said rollers.

8. The peristaltic pump according to claim 1, characterized in that, with said pump comprising n rollers, said gearwheel support element comprising pins for supporting said rollers and thus forming a separator, said or at least one of said separators comprises two opposite faces, at least one of said faces receiving at least two sets of n pins, the n pins of a first set being distributed on a circle of diameter D and the n pins of another set being distributed on a circle of diameter G so as to define two distinct reduction ratios for said peristaltic pump using corresponding rollers.

9. The peristaltic pump according to claim 1, characterized in that, with said pump comprising n rollers, said gearwheel support element comprising pins for supporting said rollers and thus forming a separator, said or at least one of said separators comprises at least two sets of n holes distributed on corresponding circles of different diameters and a single set of n spindles so as to form, with each set of holes, pins for supporting corresponding rollers, said sets of n holes defining distinct reduction ratios for said peristaltic pump.

10. The peristaltic pump according to claim 1, characterized in that it is configured in such a way that this secondary, so-called friction, driving of said rollers by said central roller combines with the geared-driving of the rotation of said rollers the drive thus formed being said to be hybrid.

11. The peristaltic pump according to claim 10, characterized in that, with said peristaltic pump comprising a geared-drive device for driving the rollers and said central roller of comprising an orifice extending along its longitudinal axis and opening onto at least one of its lateral edges, said central gearwheel has a hole placed facing the orifice of said central roller, the hole in said gearwheel and the orifice of said roller having the same female socket shape that complements the male shape of the shaft of a motor so that these can be assembled by fitting the one into the other so as to allow rotational driving of said rollers and of said central roller.

12. The peristaltic pump according to claim 10, characterized in that, with said peristaltic pump comprising a device for the geared driving of the rollers and said central roller comprising an orifice extending along its longitudinal axis and opening onto at least one of its lateral edges, said central gearwheel comprises an assembly element projecting from its opposite face from the one that is intended to face toward the motor, said assembly element being configured for assembling this central gearwheel with said central roller.

13. The peristaltic pump according to claim 7, characterized in that it comprises an externally-toothed gearwheel supported by a separator distinct from said gearwheel support element, an assembly element projecting from the opposite face of this externally-toothed gearwheel from the face that is intended to face toward the motor, said assembly element being configured to allow assembly of said externally-toothed gearwheel and of said central roller, or a central opening configured to house one end of said central roller and allow it to be assembled with said central roller, said peristaltic pump additionally comprising an individual component of which the periphery or external surface defines a shape, such as a square or hexagonal shape, intended to collaborate with an orifice of complementary shape belonging to a separator of said peristaltic pump, said individual component having a central orifice configured to allow the passage of the end of said central roller.

14. The peristaltic pump according to claim 1 characterized in that the components that make up said pump are made of plastic, the body of the peristaltic pump, also known as the pump casing, being made as two half-casings assembled with one another, said half-casings being identical.

15. A preassembled subassembly comprising a peristaltic pump according to claim 1 and a peristaltic-pump deformable tube.