EP1668249B1 - Peristaltic pump - Google Patents

Abstract

The invention relates to a multi-channel peristaltic pump, wherein the housing is constituted by a dimensionally stable support frame ( 1 ) and a tube retainer ( 2 ) clipped thereto by means of a snap connection. A rotor ( 3 ) is provided with three rotatable delivery rolls ( 33 a, 33 b, 33 c) and is mounted on the support frame ( 1 ). The tube retainer ( 2 ) is provided with a tube bed body ( 25 ) which defines on the inside a tube bed and at the end two legs ( 2 a, 2 b). Flexible tube sections ( 43 ) are received in the tube bed and can be squeezed by the delivery rolls ( 33 a, 33 b, 33 c) to peristaltically deliver a medium. The two legs ( 2 a, 2 b) are resiliently elastic so that they can be radially clipped into the support frame ( 1 ). The tube bed body ( 25 ) has a substantially omega-shaped design and is provided with a continuous inlet and outlet area that ensures a peristaltic delivery of the respective medium with only few pulsations. The inventive pump is compact in design, consists of few components and can be quickly and easily assembled.

Description

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

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

A fundamental disadvantage of peristaltic pumps is that their delivery volume is not constant but more or less pulsates. In addition, the torque to be applied by the drive motor per rotor revolution is also subject to certain fluctuations, which of course is just as undesirable.

From the DE 198 14 943 A1 is a generic peristaltic pump known. The pump is provided with a pump housing in which the pump hose and a rotor provided with two constriction means in the form of rollers is arranged. The two constricting means are diametrically opposite each other. In order to enable the most continuous delivery operation, it is proposed to enlarge the pump hose in the inlet region of the constricting means in its cross section. This is intended to provide an increased volume for delivery in the entry region and to prevent backflow of the medium from the exit side into the pump hose. Regardless of whether the desired effect can be achieved with the described features, the torque to be applied by the drive motor per rotor revolution is subject to great fluctuations. In addition, the production of such a pump hose should be expensive. Care must also be taken to ensure that the hose is inserted precisely into the pump. Since hoses with increasing service life have a tendency to become longer, there is also a risk that the widened piece of tubing migrates with increasing use and the desired effect is gradually lost.

The object of the present invention is therefore to improve a trained according to the preamble of claim 1 pump such that it allows low-pulsation conveying, is low-wear and has a high efficiency that commercial hoses can be used and that of the drive motor per rotor revolution To be applied torque peaks are minimized.

This object is achieved with a pump which is provided with the features cited in the characterizing part of claim 1.

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

Fig. 1

eine Explosionsdarstellung der peristaltischen Pumpe;

Fig. 2

die zusammengesetzte Pumpe gemäss Fig. 1 in einem ersten Querschnitt, und

Fig. 3

die zusammengesetzte Pumpe gemäss Fig. 1 in einem weiteren Querschnitt.

Hereinafter, a preferred embodiment of the invention will be explained in more detail with reference to drawings. In these drawings shows:

Fig. 1

an exploded view of the peristaltic pump;

Fig. 2

the composite pump according to Fig. 1 in a first cross section, and

Fig. 3

the composite pump according to Fig. 1 in a further cross section.

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

The dimensionally stable formed support frame 1 forms together with the hose holder 2, the actual housing of the pump. For rotatable mounting of the rotor 3 1 bearing bushes 11 are arranged on the support frame. The two end sides of the support frame 1 are formed by plates 12, which are provided with slots 15a, 15b for fixing the support frame 1 and 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 tube receptacle 2 are clamped fixable, as will be explained in more detail below.

The tube receptacle 2 has a substantially omega-shaped tubular bed body 25 which extends on the inside coaxial with the axis of rotation of the rotor 3 over approximately 130 ° circular arc portion-shaped and forms a tube bed. In the present case, omega-shaped means that the tube bed body 25 essentially has the shape of a large omega (Ω). In the end region of the tube bed body 25 forms two legs 2a, 2b, which pass from the inside to the outside in a smooth transition from a concave to a convex shape. The tube bed is divided by groove-shaped recesses 21 into six sections, which serve to receive the flexible tube sections 43. Instead of the groove-shaped recesses 21 for the formation of six sections could also be a hose mat, consisting of six interconnected hoses to Use come. In this case, the tube bed body 25 could be provided with a substantially smooth inside. The two legs 2a, 2b of the hose bed body 25 are provided on the outside with locking lugs 22, by means of which the hose receptacle 2 can be fixed to the slot-shaped recesses 13 of the support frame 1. On the outside of the hose bed body 25 radially extending reinforcing ribs 23 and axially extending reinforcing ribs 24 are provided. The radially extending reinforcing ribs 23 extend approximately 180 ° beyond the outside of the tube bed body 25. In any case, the tube receptacle 2 is dimensioned such that the two legs 2a, 2b of the tube bed body 25 are elastically resilient endwise in the radial direction and rapid fixation of the tube receptacle 2 allow 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. On the rotor body 31 three formed in the form of rollers conveyor rollers 33 are rotatably mounted. 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 connecting element 4 consists of a base member 41, are attached to the twelve pipe sections 42. At the upper parts of these pipe sections 41 a total of six flexible hose sections 43 are arranged, which create after assembly of the pump on the inside of the hose bed body 25 and for the peristaltic promotion of a medium by the conveyor rollers 33 are squeezed. It is understood that the design of the inlet and outlet area is not limited to a six-channel pump, but the number of channels is virtually arbitrarily variable.

The assembly of the items shown to a pump can be done in a few steps by first the individual tube sections 43 are attached to the connection element 4 and then the rotor 3 is inserted from the side into the loops forming tube sections 43. Thereafter, the tube holder 2 is placed in a U-shape and the rotor 3 is inserted together with the connection element 4 and the tube sections 43 connected thereto from above. Subsequently, the support frame 1 is placed and exerted a pressure, so that the axis 32 of the rotor 3 and the locking lugs 22 snap. Finally, the connection element 4 is fixed to the support frame 1. In the embodiment shown here, the connection element 4 is fastened by means of screws. Alternatively, however, for securing the connection element 4 a Snap connection are provided, which allows quick fixation of the connection element 4 on the support frame 1. The entire assembly of the pump can be done very quickly and without the aid of tools from one side, which is an advantage in automatic production.

The Fig. 2 shows a first cross section through the composite pump. From this illustration, in particular, the rotor body 31 together with the three rotatably arranged thereon and rolling on the respective tube section 43 conveyor rollers 33a, 33b, 33c, the tube holder 2 with the omega-shaped tube bed body 25 and the radial and axial reinforcing ribs 23, 24 can be seen. The reinforcing ribs 23, 24 ensure that the tube receptacle 2 is dimensionally stable and does not deform during operation under the load of the conveyor rollers 33a, 33b, 33c. If, as in the present case, a rotation direction D of the rotor 3 is assumed to be counterclockwise, then the area provided with the reference numeral 35 represents the inlet area, while the area provided with the reference numeral 36 forms the outlet area 36 of the pump. Due to the omega-shaped design of the tube bed body 25 with a "soft" inlet and outlet areas, a continuous and low pulsation peristaltic delivery of the respective medium is ensured. Another advantage of the soft inlet and outlet is the reduction of torque peaks, which would burden the engine and transmission. The pump can be operated both clockwise and counterclockwise.

Soft or continuous inlet and outlet region means that both the inlet region 35 and the outlet region 36 are designed in such a way that the conveying effective tube cross section is continuously reduced or enlarged by the conveying roller 33a, 33c rolling on the respective flexible tube section 43. It is important in this context that the tube bed body 25 is made accurately and has a high dimensional accuracy during operation, so that the predetermined distances between conveyor roller 33a, 33b, 33c and tube bed body 25 are maintained.

In addition to the aforementioned advantages, further advantages result from a continuous inlet and outlet region 35, 36, for example, in that the torque fluctuations occurring during the rotation of the rotor 3 are minimized. This is additionally facilitated by the fact that the rotor 3 is provided with three conveyor rollers 33a, 33b, 33c and the inlet area 35 is offset from the outlet area 36 by approximately 240 ° about the axis of rotation of the rotor 3, so that the first conveyor roller 33a is located approximately in the middle of the inlet region 35 when the third conveyor roller 33c is located approximately in the middle of the outlet region 36. By the shown design In addition, a high efficiency is achieved and reduces the mechanical stress on the hose sections, which increases their service life. Since the pump is designed symmetrically, it can also be operated bidirectionally, ie in both directions of rotation. From the illustration according to Fig. 2 It can also be seen that the respective tube section 43 is not completely squeezed together in the inlet region 35 and in the outlet region 36, while after the inlet region 35 it is completely squeezed out by the corresponding conveyor roller 33b and enables peristaltic delivery of the respective medium. Such a designed pump is particularly suitable for the gentle conveyance of liquid media such as blood, since the blood cells are spared 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 resilient legs 2a, 2b allows a very quick and easy installation by the hose receptacle 2 is simply clipped to the support frame. Although the legs 2a, 2b must be resiliently resilient for assembly, the tube bed body 25 must retain high dimensional accuracy and precision geometry after fixation. This is u.a. achieved in that the resilient parts are positioned and stiffened by means of external positive support on the support frame 1.

From the Fig. 3 , which shows the composite pump in a cross section between two tube sections 43, in particular the clamping fixation of the tube bed body 25 on the support frame 1 can be seen. The arranged on the outside of the hose bed body 25 locking elements 22 engage in the slot-shaped recesses 13 in the support frame 1 a. The locking elements 22 also engage positively on an upper, the slot-shaped recesses 13 delimiting web 14 of the support frame 1 at. In order to ensure a high rigidity in the flexible region of the fixed to the support frame 1 hose bed body 25, the legs 2a, 2b of the hose bed body 25 are supported by the web 14 of the support frame 1 on the outside form fit. This design ensures, in particular, the precise adherence to the optimized distances between the conveyor rollers 33a, 33b, 33c and the tube bed body 25.

The individual, elastic tube sections 43 additionally support the fixation of the tube bed body 25 on the support frame 1, since the conveyor rollers 33a, 33b, 33c of the rotor 3 load the tube bed body 25 in the radial direction via the tube sections 43 so that its fixation on the support frame 1 is additionally supported ,

The connecting element 4 is designed and tuned to the hose receiving 2 and the rotor 3, that the single hose section 43 is substantially tangential in the hose bed body 25 of the hose receiving 2 in and out again.

Although previously always referred to the illustrated in the drawings embodiment of a pump with 3 conveyor rollers, it is understood that the number of conveyor rollers in the context of the invention defined by the claims is virtually arbitrarily variable. In this case, the tubular bed body 25, the rotor 3 depending on the number of conveyor rollers wrap around at least as far as that always at least one conveyor roller 33a, 33b 33c is active, that is engaged with the respective tube section and squeezes it. The minimum wrap or the minimum wrap angle can be calculated as follows: $$\mathrm{Umschligung}=360°/\mathrm{number}-\mathrm{conveyor\; rollers}$$

When using peristaltic pumps for higher pressures, it may also be advantageous to have at least two conveyor rollers engaged at all times. In this case, the wrap is calculated according to the following formula: $$\mathrm{Umschligung}=2\times 360°/\mathrm{Number\; of\; conveyor\; rollers}$$

The calculated loop is to be understood as a minimum. Preferably, the wrap is selected to be about 10 ° greater than the wrap angle calculated by the preceding formula. By wrap is meant that part of the tubular bed which comprises the rotor coaxially.

In summary, it can be stated that a pump configured according to the invention enables low-pulsation conveying, that it has a high degree of efficiency, is low-wear and is subject to slight torque fluctuations. In addition, it is simple and compact, consists of a few parts, can be assembled quickly and without tools from a mounting direction, so that it is particularly suitable for automatic production. In addition, the existing of support frame 1 and 2 hose housing housing the pump after assembly on a high dimensional stability and stability. The pump can also be operated bidirectionally and used universally. It is also particularly suitable for the gentle promotion of liquids such as blood.

Claims (14)

1. Peristaltic pump, having a rotor (3) which is received in a housing and is provided with at least one rotatably mounted conveying roller (33a, 33b, 33c), and having a tube receptacle (2) for receiving at least one flexible tube section (43) which can be squeezed by the conveying roller (33a, 33b, 33c) in order to convey a medium peristaltically, characterized in that the tube receptacle (2) is provided with a tube bed element (25) for receiving at least one tube section (43), the inlet and/or outlet region (35, 36) of the tube bed element (25) being configured in such a way that the tube cross section which is active for conveying is continuously reduced or increased by the conveying roller (33a, 33b, 33c) which rolls on the respective tube section (43).
2. Pump according to Claim 1, characterized in that, as viewed in the rotational direction of the rotor (3), the tube bed element (25) merges in the inlet region (35) in a flowing transition from a convex into a concave shape.
3. Pump according to Claim 1 or 2, characterized in that, as viewed in the rotational direction of the rotor (3), the tube bed element (25) merges in the outlet region (36) in a flowing transition from a concave into a convex shape.
4. Pump according to one of the preceding claims, characterized in that at least two conveying rollers (33a, 33b, 33c) are provided, and in that, with regard to the rotational axis of the rotor (3), the inlet region (35) is arranged in relation to the outlet region (36) in such a way that, when a conveying roller (33a) is situated in the inlet region (35), another conveying roller (33c) is situated at the same time in the outlet region (36).
5. Pump according to one of the preceding claims, characterized in that the tube bed element (25) is of substantially omega-shaped configuration.
6. Pump according to one of the preceding claims, characterized in that the tube bed element (25) is wrapped coaxially around the rotor (3) at least partially.
7. Pump according to one of the preceding claims, characterized in that the tube bed element (25) forms the housing of the pump together with a loadbearing frame (1), the tube bed element (25) having on the end side two limbs (2a, 2b) which are resilient in the radial direction in a spring-elastic manner and are provided with latching elements, by means of which the tube bed element (25) can be clipped in on cut-outs (13) on the loadbearing frame (1) in the manner of a snap-in connection.
8. Pump according to one of the preceding claims, characterized in that the tube bed element (25) is configured in such a way that its accuracy of shape and its fixing on the loadbearing frame (1) are assisted by the force action of the squeezed tube section or the squeezed tube sections (43) in addition to the spring-elastic internal stress of the limbs (2a, 2b).
9. Pump according to one of the preceding claims, characterized in that the tube bed element (25) is provided with a multiplicity 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 element (25) is provided on the inside with a multiplicity of groove-shaped recesses (21) for receiving and guiding a multiplicity of tube sections (43).
11. Pump according to one of the preceding claims, characterized in that the conveying rollers (33a, 33b, 33c) are of roll-shaped configuration and extend in the axial direction beyond the groove-shaped recesses (21).
12. Pump according to one of the preceding claims, characterized in that the respective tube section (43) is guided substantially tangentially into the tube bed element (25) and out of it again.
13. Pump according to one of the preceding claims, characterized in that the rotor (3) is provided with at least two conveying rollers (33a, 33b, 33c), and in that the tube bed element (25) is wrapped coaxially around the rotor (3) by at least 360° divided by the number of conveying rollers.
14. Pump according to one of Claims 1 to 12, characterized in that the rotor (3) is provided with three conveying rollers (33a, 33b, 33c) and the inlet region (35) is offset with respect to the outlet region (36) about the rotational axis of the rotor (3) by from 210 to 270°, preferably by approximately 240°.

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