WO2005031166A1

WO2005031166A1 - Peristaltic pump

Info

Publication number: WO2005031166A1
Application number: PCT/CH2004/000390
Authority: WO
Inventors: Stephan Michels; René Fässler; Corinne SCHÄRER; Daniel Saxer
Original assignee: Ismatec Sa, Laboratoriumstechnik
Priority date: 2003-09-26
Filing date: 2004-06-25
Publication date: 2005-04-07
Also published as: EP1680600B1; EP1680600A1; ATE381673T1; US20070104599A1; DE502004005771D1

Abstract

The invention relates to a peristaltic pump in which a case is formed by a dimensionally stable supporting frame (1) and by a tube reception device (2) formed thereon by clipping. A rotor (3) provided with three rotatable transport rollers (33a, 33b, 33c). Said tube reception device (2) is provided with a tube bearing body (25) which forms a bed for the tubes on the internal surface and comprises two legs (2a, 2b) on the ends thereof. The tube flexible sections (43) are compresses by said transport rollers (33a, 33b, 33c) in order to ensure the peristaltic conveyance of a medium. The two legs (2a, 2b) are elastically deformable in a radial direction in order to be elastically adaptable on the supporting frame (1). The bearing body (25) is substentially omega-shaped and provided with uniform input and output areas which ensure a medium continuous low-pulsed peristaltic conveyance. The inventive pump is constructed in such a way that it is small-sized, comprises few spare parts and is rapidly and easily mounted.

Description

Peristaltic pump

The invention relates to a peristaltic pump according to the preamble of claim 1.

Peristaltic pumps of the type in question are known in principle. They are used to pump a wide variety of liquid or gaseous media.

From EP 1 137 886 a roller pump for peristaltic delivery of media is known, which is provided with a hose cassette. The hose cassette is fixed to the roller pump by means of a lockable cover. The conveyor rollers are resiliently supported on a rotating body. As can be seen in particular from the illustration according to FIG. 1 of this document, such a roller pump together with the hose cassette has a relatively large length and accordingly requires a lot of space.

A peristaltic pump is known from WO 02/25112, which is provided with a multi-part housing in which a reduction gear is arranged. The pressure tubes for squeezing a flexible hose section are integrated in the reduction gear. Such a pump consists of a large number of individual parts, is relatively expensive to manufacture and takes a long time to assemble.

Finally, US Pat. No. 5,857,843 discloses a peristaltic pump which has a support frame on which the rotor is exchangeably mounted. The support frame is provided with pawl-shaped locking elements which serve to fix a plate forming the upper housing part. The plate is concave on the inside and serves to accommodate a flexible hose section. Although such a pump is very simple and inexpensive to manufacture, it has, among other things. the disadvantage that only a comparatively small tube or circular arc section is available for peristaltic delivery. In addition, the plate should be relatively unstable, particularly in the transverse direction, which has a negative effect on a constant conveying rate. In addition, the force of the squeezed hose can cause the locking elements to bend apart.

The object of the present invention is to improve a pump designed in accordance with the preamble of claim 1 in such a way that it is compact and can be produced inexpensively, that it can be assembled easily and quickly, and that it is very stable when assembled and has a high degree of shape accuracy. This object is achieved with a pump with the in the characterizing part of the claim

1 listed features is provided.

Advantageous developments of the peristaltic pump are defined in the dependent claims 2 to 14.

A preferred exemplary embodiment of the invention is explained in more detail below with reference to drawings. In these drawings:

Figure 1 is an exploded view of the peristaltic pump.

2 shows the assembled pump according to FIG. 1 in a first cross section, and

3 shows the assembled pump according to FIG. 1 in a further cross section.

Figure 1 shows a six-channel peristaltic pump in an exploded view. The pump essentially consists of a support frame 1, a hose receptacle 2, a rotor 3 and a connecting element 4 with six hose sections 43 arranged thereon. A gearwheel 5 provided for coupling to a drive motor (not shown) is also shown.

The dimensionally stable support frame 1 forms together with the hose receptacle

2 the actual housing of the pump. For the rotatable mounting of the rotor 3, two bearing bushes 11 are arranged on the support frame 1. The two end faces of the support frame 1 are formed by plates 12 which are provided with slots 15a, 15b for fixing the support frame 1 or the entire pump. Finally, the support frame 1 is provided on both sides with a plurality of slot-shaped recesses 13, in which locking elements 22 of the hose receptacle 2 can be clamped, as will be explained in more detail below.

The hose receptacle 2 has an essentially omega-shaped hose bed body 25 which extends on the inside coaxially to the axis of rotation of the rotor 3 over approximately 130 ° in the form of a circular arc and forms a hose bed. In the present case, omega-shaped means that the tubular bed body 25 essentially has the shape of a large omega (Ω). In the end region, the tubular bed body 25 forms two legs 2a, 2b, which transition from a concave to a convex shape in a smooth transition. The tube bed is divided into six sections by groove-shaped recesses 21, which serve to accommodate the flexible tube sections. Instead of the groove-shaped recesses 21 for - ~

A tube mat consisting of six interconnected tubes could also be used to form six sections. In this case, the tubular bed body 25 could be provided with a largely smooth inside. The two legs 2a, 2b of the tube bed body 25 are provided on the outside with locking elements 22, by means of which the tube receptacle 2 can be fixed to the slot-shaped recesses 13 of the support frame 1. Radially extending reinforcing ribs 23 and axially extending reinforcing ribs 24 are provided on the outside of the tubular bed body 25. The radially extending reinforcing ribs 23 extend approximately 180 ° over the outside of the tubular bed body 25. In any case, the tubular receptacle 2 is dimensioned such that the two legs 2a, 2b of the tubular bed body 25 are resiliently resilient in the radial direction at the ends, and the tubular receptacle is quickly fixed 2 enable in the sense of a snap connection on the support frame 1.

The rotor 3 consists of a rotor body 31 which is provided with a central axis 32 which is inserted into the bearing bushes 11 of the support frame 1. Three conveyor rollers 33 in the form of rollers are rotatably mounted on the rotor body 31. The rotor body 3 is preferably made of plastic, while the central axis 32 and the conveyor rollers 33 are preferably made of metal.

The connection element 4 consists of a base element 41 to which twelve pipe sections 42 are fastened. A total of six flexible hose sections 43 are arranged on the upper parts of these pipe sections 42, which, after the pump has been assembled, put on the inside of the hose bed body 25 and can be squeezed off by the conveyor rollers 33 for the peristaltic conveying of a medium. It goes without saying that the design of the inlet and outlet area is not limited to a six-channel pump, but the number of channels can be varied practically as desired.

The individual parts shown can be assembled into a pump in a few simple steps, by first fastening the individual hose sections 43 to the connecting element 4 and then inserting the rotor 3 from the side into the hose sections 43 forming the loops. Then the hose holder 2 is set up in a U-shape and the rotor 3, together with the connecting element 4 and the hose sections 43 connected to it, are pushed in from above. The support frame 1 is then placed on and a pressure is exerted so that the axis 32 of the rotor 3 and the latching elements 22 snap into place. Finally, the connection element 4 is fixed on the support frame 1. At the The embodiment shown here is attached to the connecting element 4 by means of screws. Alternatively, a snap connection can be provided to fasten the connection element 4, which enables the connection element 4 to be fastened to the support frame 1 quickly. The entire assembly of the pump can be done from one side and without the aid of tools, which is an advantage in automatic production.

2 shows a first cross section through the assembled pump. This illustration shows, in particular, the rotor body 31 together with the three conveyor rollers 33a, 33b, 33c which are rotatably arranged thereon and roll on the respective hose section 43, the hose holder 2 with the omega-shaped hose bed body 25 and the radial and axial reinforcing ribs 23, 24. The reinforcing ribs 23, 24 ensure that the hose holder 2 is dimensionally stable and does not deform during operation under the load on the conveyor rollers 33a, 33b, 33c. The omega-shaped design of the tubular bed body 25 with a “soft” inlet and outlet area ensures a continuous and low-pulsation peristaltic conveying of the respective medium. Another advantage of the soft inlet and outlet is the reduction of torque peaks, which would put a load on the engine and transmission. If a direction of rotation D in the counterclockwise direction is assumed, the area provided with the reference number 35 represents the inlet area, while the area provided with the reference number 36 forms the outlet area of the pump. The pump can be operated both clockwise and counterclockwise.

A soft or continuous inlet and outlet area means that both the inlet area 35 and the outlet area 36 are designed in such a way that the conveying-effective hose cross-section is continuously reduced or enlarged by the conveying roller 33a, 33c rolling on the respective flexible hose section 43. It is important in this context that the tubular bed body 25 is manufactured precisely and has a high degree of dimensional accuracy during operation, so that the predetermined distances between the conveyor roller 33a, 33b, 33c and tubular bed body 25 are maintained.

In addition to the advantage mentioned, a continuous inlet and outlet area 35, 36 results in further advantages, for example by minimizing the torque fluctuations that occur during the rotation of the rotor 3. This is additionally favored by the fact that the rotor 3 is provided with three conveyor rollers 33a, 33b, 33c and the inlet area 35 is offset by approximately 240 ° about the axis of rotation of the rotor 3 with respect to the outlet area 36, so that the first conveyor roller 33a is approximately in the middle of the inlet area 35 when the third conveyor roller is 33c is located approximately in the middle of the outlet area 36. The design shown also achieves a high degree of efficiency and reduces the mechanical load on the hose sections 43, which increases their service life. Since the pump is designed symmetrically, it can also be operated bidirectionally, ie in both directions of rotation. 2 also shows that the respective hose section 43 in the inlet area 35 and in the outlet area 36 is not completely squeezed, while after the inlet area 35 it is completely squeezed out by the corresponding conveying roller 33b and enables peristaltic conveying of the respective medium , A pump designed in this way is also particularly suitable for the cell-friendly conveying of liquid media such as blood, since the blood cells are protected by the specific design of the inlet and outlet areas 35, 36.

The formation of the hose receptacle 2 with a dimensionally stable hose bed body 25 and elastically flexible legs 2a, 2b enables a very quick and simple assembly by simply clipping the hose receptacle 2 onto the supporting frame. Although the legs 2a, 2b must be resilient for installation, the tubular bed body 25 must retain a high dimensional stability and a precise geometry after fixing. Among other things, this achieved in that the resiliently flexible parts are positioned and stiffened on the support frame 1 by means of external positive support.

3, which shows the assembled pump in a cross section between two hose sections 43, shows in particular the clamping fixation of the hose bed body 25 on the support frame 1. The locking elements 22 arranged on the outside of the tubular bed body 25 engage in the slot-shaped recesses 13 in the support frame 1. The latching elements 22 also engage in a form-fitting manner on an upper web 14 of the supporting frame 1 that delimits the slot-shaped recesses 13. In order to ensure a high degree of rigidity in the flexible region of the tubular bed body 25 fixed to the supporting frame 1, the legs 2a, 2b of the tubular bed body 25 are positively supported on the outside by the web 14 of the supporting frame 1. This design also ensures in particular the precise maintenance of the optimized distances between the conveyor rollers 33a, 33b, 33c and the inside 25a of the tubular bed body 25.

The individual, elastic tube sections 43 additionally support the fixing of the tube bed body 25 to the support frame 1, since the conveyor rollers 33a, 33b, 33c of the rotor 3 radially extend the tube bed body 25 via the tube sections 43 Load direction so that its fixation on the support frame 1 is additionally supported.

The connection element 4 is designed and matched to the hose receptacle 2 and the rotor 3 in such a way that the individual hose section 43 is guided substantially tangentially into and out of the hose bed body 25 of the hose receptacle 2.

Although reference was always made to the exemplary embodiment of a pump with 3 conveyor rollers shown in the drawings, it is understood that the number of conveyor rollers can be varied practically as desired within the scope of the invention defined by the claims. Depending on the number of conveyor rollers, the tubular bed body 25 must wrap around the rotor 3 at least to such an extent that at least one conveyor roller 33a, 33b 33c is always active, i.e. engages with the respective hose section and squeezes it. The minimum wrap or the minimum wrap angle can be calculated as follows:

Wrapping = 360 ° / number of conveyor rollers

When using peristaltic pumps for higher pressures, it can also be advantageous to have at least two conveyor rollers in operation at all times. In this case, the wrap is calculated using the following formula:

Wrapping = 2x360 number of conveyor rollers

The calculated wrap is to be understood as a minimum dimension. The wrap is preferably chosen to be approximately 10 ° larger than the wrap angle calculated according to the preceding formula. Wrapping is to be understood as that part of the hose bed which coaxially encompasses the rotor.

In summary, the following advantages of a peristaltic pump designed according to the invention can be stated:

- It is simply constructed and consists of a few parts;

- It can be assembled from one assembly direction and is therefore suitable for automatic production; - It can be assembled quickly and without tools;

- After assembly, it has a high level of shape (rigidity);

- It can be manufactured inexpensively;

- It is compact and light;

- It can be single or multi-channel;

- It is suitable for the gentle delivery of liquids such as blood;

- It can be operated bidirectionally and used universally.

- It reduces pulsation, torque peaks, is low-wear and therefore has an increased efficiency.

Claims

_ _Patent claims

1. peristaltic pump, with a rotor (3) accommodated in a housing, which is provided with at least one rotatably mounted conveyor roller (33a, 33b, 33c), and a hose receptacle (2) for receiving at least one flexible hose section (43), which can be squeezed by the conveyor roller (33a, 33b, 33c) for the peristaltic conveying of a medium, characterized in that the housing is formed by a dimensionally stable support frame (1) and the hose receptacle (2), the hose receptacle (2) at least partially in this way is designed to be spring-elastic so that it can be clipped onto the support frame (1) in the sense of a snap connection, and the hose receptacle (2) is fixed in a dimensionally stable manner on the support frame (1) after the clipping.

2. Pump according to claim 1, characterized in that the hose receptacle (2) is provided with a hose bed body (25) which forms a hose bed on the inside and two legs (2a, 2b) at the end, the latter being resilient in the radial direction ,

3. Pump according to claim 2, characterized in that the tubular bed body (25) wraps around the rotor (3) at least partially coaxially.

4. Pump according to claim 2 or 3, characterized in that the two legs (2a, 2b) of the tubular bed body (25), in the region of the respective leg end, in a smooth transition from a concave to a convex shape.

5. Pump according to one of the preceding claims, characterized in that the tubular bed body (25) is substantially omega-shaped.

6. Pump according to one of the preceding claims, characterized in that the support frame (1) with recesses (13) and the legs (2a, 2b) of the tubular body (25) at the end with locking elements (22) for clipping onto the recesses (13) of the support frame (1) are provided.

7. Pump according to claim 6, characterized in that the latching elements (22) on the outside of the legs (2a, 2b) are arranged and the support frame (1) above the recesses (13), on the inside of the tubular body (25) facing , with a web (14) for positive and / or non-positive support of the each leg (2a, 2b) of the tubular bed body (25) is provided on the outside.

8. Pump according to one of the preceding claims, characterized in that the tubular bed body (25) is designed such that its shape and fixation on the support frame (1) in addition to the resilient internal stress of the legs (2a, 2b) by the force of the squeezed hose section or the squeezed hose sections (43) is supported.

9. Pump according to one of claims 2 to 8, characterized in that the tubular bed body (25) is provided with a plurality of radially and / or axially extending reinforcing ribs (23, 24).

10. Pump according to one of the preceding claims, characterized in that the tube bed body (25) is provided on the inside with a plurality of groove-shaped recesses (21) for receiving and guiding a plurality of tube sections (43).

11. Pump according to claim 9, characterized in that the respective conveyor roller (33a, 33b, 33c) is roller-shaped and extends in the axial direction over the groove-shaped recesses (21).

12. Pump according to one of the preceding claims, characterized in that the respective hose section (43) is guided substantially tangentially into the hose bed body (25) and also out again.

13. Pump according to one of the preceding claims, characterized in that the rotor (3) is provided with at least two conveyor rollers (33a, 33b, 33c) and that the tubular bed body (25) divides the rotor (3) by at least 360 ° Number conveyor rollers coaxially wrapped.

14. Pump according to one of claims 1 to 12, characterized in that the rotor (3) is provided with three conveyor rollers (33a, 33b, 33c) and the inlet area (35) relative to the outlet area (36) by 210 to 270 °, is preferably offset by approximately 240 ° about the axis of rotation of the rotor (3).