Hose roller pump

Abstract

The invention relates to a peristaltic pump, comprising a pump housing, in the pump bed of which a rotor is accommodated, which rotor has at least two pressing elements offset from one another in the circumferential direction, and which pump housing has a support surface which extends in an arcuate manner about the rotor axis and which is radially spaced from the rotor, the support surface is provided for supporting a hose segment that can be introduced between the support surface and the rotor. According to the invention, the rotor has a rocker arm which is pivotably fixed to the rotor in a spring-loaded manner, an introduction aid by means of which the hose segment can be pressed during penetration of the hose segment into the pump bed, and a hose guide element by means of which the hose segment can be oriented in the middle of the pressing element. In order to maintain the penetration process as simply as possible for the user and to maximally protect the hose segment to be penetrated into the peristaltic pump from damage while simplifying the structure, not only the auxiliary part is introduced, but also the hose guide element is integrated into the rocker arm adjacent to the pressing element in the rotational direction of the rotor.

Description

Technical Field

[0001] The invention relates to a hose roller pump or peristaltic pump, i.e. a volumetric pump, in which the medium to be conveyed is squeezed through the hose by external mechanical deformation of the hose. Such pumps are usually used in devices for extracorporeal blood treatment, in particular dialysis machines, for conveying fluids, in particular blood. The fluid is conveyed from the low-pressure side to the high-pressure side by means of a peristaltic pump, wherein an elastically deformable fluid line in the form of a hose segment (the hose segment is also referred to as a pump segment) arranged between the low-pressure side and the high-pressure side is deformed, in particular squeezed, by means of at least two squeezing elements between a support surface of a pump bed and a rotor rotating relative to the support surface. Background Art

[0002] In peristaltic pumps, as are known, for example, from EP 1 749 549 B1 and as are known in Figure 8 and Fig. 9 As schematically shown in FIG. 1 , two pressure elements 320 in the form of elastically supported pressure rollers are arranged diametrically offset relative to each other on a rotor 310 rotatably supported in a pump housing 305 with a pump bed 307, and the support surface 330 is formed by a circular arc surface, which extends over a sufficiently large central angle of more than 180°. The pressure rollers are rotatably supported on a rocker arm 341, which is pivotally fixed to the rotor 310 by means of a hinge pin 338 and an axis A338 and is loaded with a radially outwardly directed force FR by a compression spring 336 (see FIG. 1 ). Figure 8 ).

[0003] In order to put the peristaltic pump into operation, it is necessary to Figure 8 A hose segment, i.e. a pump segment, not shown in greater detail, is guided from a connection point PN on the low-pressure side above the rotor 310 in an arc shape following the support surface 330 to a connection point PP on the high-pressure side and is then inserted into the pump bed 307 by manual rotation of the rotor 310 in the direction of the arrow D. As an insertion aid or introduction aid for supporting manual insertion, the known peristaltic pump has two guide protrusions 380 in the form of hooks 360 carried by the rotor 310, which are arranged between two pressure rollers 320. In contrast to the automatic insertion scheme of the pump segment, in which the rotor is automatically oriented into the optimal insertion position, in the case of the peristaltic pump known from document EP 1749549B1, the user must take care to insert the hose before the hook 360 in order to prevent it from getting stuck. To this end, the rotor 310 must be manually rotated as in Figure 8 In order to guide the hose section already caught by the hook 360 and to orient it centrally relative to the pressing element, guide pins 370 , 390 inserted into the rotor and serving as hose guide elements are additionally used, which run behind the hook 360 . Summary of the invention

[0004] The object of the present invention is to improve a peristaltic pump of the corresponding type in such a way that the threading process is simpler for the user to design with a simplified design, wherein the hose section to be threaded into the peristaltic pump should be protected as much as possible from damage.

[0005] This object is achieved according to the invention.

[0006] According to the new development, both the introduction aid and the hose guide element are integrated into the rocker arm adjacent to the extrusion element in the direction of rotation of the rotor. This reduces the number of components and thus also the manufacturing and assembly costs, since only the rocker arm needs to be installed for this purpose. Since the introduction aid is adjacent to the assigned extrusion element, i.e., directly in front of it in each case, manual insertion of the pump segment is possible without the user having to pay attention to the specific position of the rotor.

[0007] Advantageously, the rocker arm is mounted on the rotor by means of a pivot bearing which is arranged offset relative to the displacement element in the direction of rotation of the rotor, wherein the introduction aid and the hose guide element are seated on the pivot bearing. With this design, the structure of the rocker arm with the integrated introduction aid and hose guide can be designed to be particularly compact.

[0008] Tests have shown that, due to the arrangement according to the invention of the introduction aid on the pivot bearing of the rocker arm, it is sufficient to construct the introduction aid as a simple pin-shaped guide body for protective and secure insertion of the hose segment, which extends from the pivot bearing approximately in a radial direction away from the rotor axis in the direction of the support surface and which, when viewed in cross section, has approximately a rounded wedge shape pointing in the direction of rotation of the rotor, which is inclined toward the pump bed at an acute angle of preferably between 30° and 50°.

[0009] It is further advantageous that the guide body has two functional surfaces, wherein the outer functional surface running in front in the direction of rotation of the rotor and facing away from the middle plane of the rocker arm is constructed as a rounded wedge surface, and the inner functional surface facing the middle plane is formed by a cylindrical segment surface preferably connected to the wedge surface in a stepless manner. When the rotor is rotated manually, the rounded wedge surface presses the hose segment to be inserted gently downward into the pump bed, wherein the rounded geometry prevents damage to the hose segment. The cylindrical segment surface connected to the wedge surface can be used in an advantageous manner to guide the hose segment centrally relative to the extrusion element during the operation of the peristaltic pump. It should of course be noted here that the quality of the surface of the guide body that contacts the hose segment is implemented so that the hose segment is protected as well as possible.

[0010] According to the application, the cross section of the guide body can have very different shapes, provided that the wedge surface and the cylindrical segment surface are formed on the side facing the hose section. However, if the cross section of the guide body has a center axis, this results in simplified production, especially in the case where the guide body is attached to the rocker arm as a separate component. For the alternative case, i.e. the rocker arm and guide body are formed in one piece, an additional advantage is that the guide body is additionally supported on the rocker arm by means of struts following the center axis. This design allows the guide body to be formed in a filamentary but stable manner, which even opens up the possibility of a construction with a hollow profile.

[0011] If the guide body is arranged on the pivot bearing hole of the rocker arm, preferably mounted integrally on the pivot bearing hole, the radial supporting forces and bending forces applied to the guide body during insertion can be well introduced into the rocker arm, because the pivot bearing hole is stably supported by the pivot axis and is accordingly subjected to only minimal deformation.

[0012] Another advantageous embodiment of the peristaltic pump is that the rocker arm is provided with a stop surface for the compression spring at its end section facing away from the pivot bearing hole, and the pressure element is arranged, for example rotatably supported, between the pivot bearing hole and the stop surface. In this way, the rocker arm acquires a compact shape, so that sufficient free space remains on the circumference of the rotor for forming further functional surfaces, for example guide surfaces for hose segments.

[0013] Preferably, a further second guide body is assigned to the first guide body constituting the above-mentioned introduction aid, which second guide body is constructed and oriented symmetrically to the first guide body relative to a horizontal plane parallel to the pump bed. The cylindrical segment surfaces of the two mirror-arranged guide bodies facing each other thus constitute the functional surface of the hose guide element. Here, the integration of the introduction aid and the hose guide element into the rocker arm is ensured with further reduced manufacturing costs. Due to the mirror-arranged and oriented guide bodies, the guide bodies guide the hose segments in a funnel-shaped and protective manner to the center of the relevant extrusion element when the peristaltic pump is in operation, which has a positive effect on the delivery accuracy of the peristaltic pump.

[0014] The production of the rocker arm is further simplified if the horizontal plane, with respect to which the two guide bodies are arranged symmetrically, is at the same time the plane of symmetry of the rocker arm.

[0015] Advantageously, the hose section is thus also protected better against wear if the introduction aid and preferably also the hose guide element are formed and / or coated from a material having sliding properties which minimize wear.

[0016] The rocker arm with integrated introduction aid and integrated hose guide element constructed according to the present application can be manufactured in very different ways. The rocker arm can also be made of different materials and assembled into an integral structural unit, wherein in this case, very different forming manufacturing methods, such as CNC milling technology, can be used. When the rocker arm is constructed as an integral component manufactured by the metal injection molding (MIM) method, special advantages are obtained in terms of manufacturing, installation and material consumption. It has been shown that in this manufacturing method, the surface quality of the hose segment is guaranteed to be protected to the greatest extent without further processing. It should be pointed out that the manufacture of the rocker arm by the MIM method (metal injection molding) is to be regarded as a separate invention, which is independent of the geometric design of the rocker arm and requires separate protection for this separate invention. In this case, the rocker arm of the rotor is preferably made of high-strength stainless steel with very good chemical properties. This manufacturing makes it possible to integrate additional functions, such as insertion aids and hose segment guides, while significantly reducing the raw materials used and manufacturing costs compared to cutting manufacturing. Here, mechanical reprocessing can be limited to a minimum by the forming MIM method. In addition, the MIM method allows fine contours (e.g. reinforcing ribs) to be realized, thereby further reducing the mass of the component while maintaining the same strength. These fine contours can only be produced with difficulty or not at all using milling technology. Due to the good surface quality that can be achieved with the MIM method, no special post-processing is required in the area of ​​the surface that comes into contact with the hose segment, which can also serve to reduce production costs. Other powder injection molding methods, such as ceramic powder injection molding, can also be used to produce the rocker arm.

[0017] Tests have shown that such materials, for example austenitic heat-resistant chromium-nickel steel, such as is known, for example, under the name 1.4841 (X15CrNiSi25-21), can be easily produced in the MIM method with a sufficiently high density and the components produced therefrom have optimal properties for peristaltic pumps. The rocker arms produced in this way are chemically stable to very different media and have such high strength, using only a few cm3 of minimal material, that on the one hand the contact force of the rollers during conveying operation of very different media with a groove structure is ensured and on the other hand the fit of the roller shaft is ensured without deformation of the rocker arm. This results in the additional advantage that the chemical properties of the material obviate the need for additional surface treatments, such as painting or anodizing.

[0018] The introduction aid and the hose guide geometry are integrated into the rocker arm. This reduces the production and installation costs. The hose guide geometry has two areas. Figure 6 The area at the upper trumpet, which is indicated by a dashed line in the figure of FIG, is a rounded bevel, which presses the hose downwards during insertion. The rounded geometry prevents damage to the hose. Figure 6 The circular surfaces on the upper and lower trumpets, indicated by dashed lines, position the hose during operation so that the pump segment is guided centrally on the pressure roller. The quality of the surface is selected in the area of ​​the hose guidance so that the hose is not damaged. The surface quality can be produced without special post-processing. By arranging the insertion aid directly in front of the pressure roller, the user does not have to pay attention to the special position of the rotor during manual threading. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] An embodiment of the present invention is explained in more detail below with the aid of a schematic diagram. It is shown:

[0020] Figure 1 is a perspective view of an exemplary embodiment of a peristaltic pump that can be used in conjunction with an apparatus for extracorporeal blood treatment;

[0021] Figure 2 is based on the inserted hose segment Figure 1 A three-dimensional view of a peristaltic pump, wherein the hose segment forms a pump segment;

[0022] Figure 3 is based on Figure 1 and Figure 2 A three-dimensional view of the rotor used in the peristaltic pump;

[0023] Figure 4 is a perspective view of a rotor base of a peristaltic pump with an attached rocker arm;

[0024] Figure 5 From Figure 2 Different viewing directions show a perspective view of the rotor;

[0025] Figure 6 Shown on a strongly exaggerated scale along Figure 5 In the viewing direction of the arrow "VI" in Figure 1 and Figure 2 A side view of a rocker arm used in a peristaltic pump;

[0026] 7A to 7D is a schematic top view of a peristaltic pump for illustrating different stages of penetration of a pump segment;

[0027] Figure 8 is a schematic top view of a peristaltic pump according to the prior art; and

[0028] Fig. 9 is based on Figure 8 A stereoscopic view of the rotor used in a peristaltic pump.

[0029] Among them: A-rotor axis; D-rotation direction; PN-low pressure connection part; PP-high pressure connection part; PS-pump segment; ES-symmetry plane; F1-functional surface; F2-functional surface; FR-radial direction; 5-pump housing; 7-pump bed; 10-rotor; 20-extrusion element; 30-support surface; 38-pivot bearing / hinge pin; 40-rotor base; 42-rotor cover; 44-button; 46-guide surface; 48-guide surface; 50-bearing hole; 52-bearing hole; 54-stop surface; 56-compression spring; 58-upper -Arch arm; 60-lower arch arm; 62-upper supporting part; 64-lower supporting part; 66-rotation axis; 70-upper guide body; 72-lower guide body; 76-pillar; 78-free space; 305-housing; 307-pump bed; 310-rotor; 320-extrusion element; 330-support surface; 341-rocker arm; 336-compression spring; 338-hinge pin; A338-axis; 341-rocker arm; 360-hook; 370-guide pin; 380-guide protrusion; 390-guide pin. DETAILED DESCRIPTION

[0030] exist Figure 1 , for example, is used in a dialysis machine. The task of the peristaltic pump is to convey a defined volume of medium, for example blood or dialysis fluid, by deforming and clamping an elastically deformable fluid line. Peristaltic pumps for conveying blood usually convey from the negative pressure side PN (low pressure connection) to the positive pressure side PP (high pressure connection).

[0031] As in Figures 1 to 3 As shown in the figure, the peristaltic pump has Figure 1 The rotor or pump housing 5 shown in the figure is unfolded, in which a rotor 10 is accommodated which can rotate about a rotor axis A and has at least two displacement elements 20, in this case pressure rollers, which are offset in the circumferential direction, for example, in diameter. The pump housing 5 comprises a pump bed 7 which extends in an arc shape about the rotor axis A and has a support surface 30 which is radially spaced from the rotor 10. The support surface 30 is provided for radially supporting a displacement element which can be introduced between it and the rotor 10. Figure 2 The pump segment PS shown in FIG. 2 is supported, for example, in a spring-loaded manner. Figure 1 The rocker arm is mounted on a rocker arm (not shown in detail) which is itself fastened to the rotor 10 via a joint pin 38 so that it can be pivoted.

[0032] The hose segments used in the peristaltic pump, that is to say accommodated in the pump bed 7, are referred to below as pump segments. Figure 1The hose section in the pump bed 7, which is not shown in the figure, is supported radially on the support surface 30. The support surface 30 is usually formed by a cylinder surface, but the cylinder surface can also be recessed in a groove shape. The direction of rotation of the rotor 10 is indicated by the arrow D when conveying the fluid.

[0033] Figure 3 The rotor 10 is shown in detail. The rotor has a rotor base body 40 (not shown in more detail) and a rotor cover 42. The rotor 10 can be removed from a drive shaft (not shown in more detail) by means of a laterally operable button 44. The pressing element 20 is rotatably mounted on a rocker arm 41 which is supported elastically in an articulated manner on the rotor base body 40.

[0034] The rotor cover 42, which rotates with the rotor 10, carries guide surfaces 46, 48 in the region of the extrusion element 20, wherein one guide surface 46 runs in front of the extrusion element 20 and the other guide surface 48 runs behind the extrusion element 20. The guide surfaces 46, 48 are therefore arranged and designed on both sides adjacent to the extrusion element 20 in the circumferential direction, so that the guide surfaces together with the support surface 30 form a circular segment-shaped guide channel, in which the pump segment inserted into the pump bed 7 is radially captured with a predetermined clearance fit. The pump segment can be fixed to the pump bed 7 during the operation of the peristaltic pump by means of a fitting body, not shown in more detail, which can be fixed immovably in a corresponding connection of the pump housing 5.

[0035] Before the peristaltic pump is put into operation, the hose segment, which during operation of the pump becomes the pump segment of the device, must be introduced or inserted into the pump bed 7 and centered with respect to the squeeze element 20. The initial phase of this insertion is Figure 2 Presented in.

[0036] The pump segment denoted by PS is first Figure 2 , so that the pump segment extends from the connection point PN on the low-pressure side in an arc-shaped manner following the rotor 10 above the support surface 30 to the connection point PP on the high-pressure side. The pump segment PS is still completely above the rotor 10 at this stage, more precisely above the rotor cover 42. Now, in order to insert the pump segment PS into the pump bed 7 by manually rotating the rotor 10 in the direction of the arrow D and to keep the stress on the pump segment PS as small as possible and the handle as simple as possible, the rotor 10 carries an introduction aid and a hose guide element, by means of which the hose or pump segment can be pressed during the insertion of the hose segment or pump segment PS into the pump bed 7, and by means of which the hose segment or pump segment PS can be centered relative to the extrusion element 20. Next, with the aid of Figures 4 to 6 The introduction aid and the hose guiding element are described in more detail.

[0037] The support of the introduction aid and the hose guide element is in the present invention a rocker arm 41 which is pivotably mounted on the rotor base body 40. More precisely, the introduction aid and the hose guide element are integrated into the rocker arm 41 as follows:

[0038] As shown in FIG. 40 , Figure 4 As shown in FIG. 4 , the rotor cover 42 is removed from the rotor base, and the rocker arm 41 is pivotally fixed to the hinge pin 38 by means of two bearing holes 50, 52 with a pivot axis A38. Figure 4 and Figure 6 As can be seen in FIG. 4 , the rocker arm 41 has a stop surface 54 for a compression spring 56 at its end section facing away from the bearing holes 50, 52, by which the rocker arm 41 is loaded with a pressure directed away from the rotor base body 40. Figure 4 As can be seen from the illustration, between the bearing holes 50, 52 and the stop surface 54, the rocker arm 41 is designed in the form of a slightly convexly curved frame with two frame arms 58, 60 located in parallel spacing, which are themselves designed for the rotation axis 66 of the pressure roller 20 (see Figure 4 ) bearing positions 62, 64. The rocker arm 41 has a symmetry plane ES, relative to which the pressure roller 20 is also centrally positioned in this way.

[0039] The guide bodies 70, 72 which are formed on the pivot bearing, more precisely on the bearing openings 50, 52, i.e. integrated into the rocker arm 41 as close as possible to the pressure roller 20, serve as an introduction aid and guide element for the pump segment PS, and which extend from the pivot bearing, i.e. from the axis A38 of the joint pin 38, approximately in the radial direction from the rotor axis A, i.e. from the rotor base body 40, so far that they (e.g. from the Figure 2 As can be seen in Figure 2 The guide body 70 , in which only the upper part is visible, comes as close as possible to the support surface 30 when the rotor 10 rotates.

[0040] The upper guide body 70 forms an introduction aid, which is described in more detail below with regard to its function, and the two guide bodies 70 , 72 together serve as a hose guide element, by means of which the pump segment PS is centered relative to the pressure element or pressure roller 20 .

[0041] At least the upper guide body 70 (in the illustrated embodiment, however, both guide bodies 70, 72) of the introduction aid are formed in cross section and in accordance with Figure 6 In a radial view of the rotor, the rotor has a substantially rounded wedge shape pointing in the direction of rotation D of the rotor, which is at an acute angle WA (see Figure 6 ) is inclined relative to the pump bed 7 and therefore relative to the symmetry plane ES of the rocker arm 41 which is parallel thereto.

[0042] At least the upper guide body 70 has two functional surfaces F1 and F2, wherein the outer functional surface F1 (in the direction of rotation D) running forward and facing away from the plane of symmetry ES Figure 6 The rounded wedge surface is formed by a dot-dash line in FIG. 1 and a functional surface F2 (in FIG. 1 ) facing the inner side of the symmetry plane ES. Figure 6 The guide body 72 (indicated by dashed lines in FIG. 1 ) is formed by a cylindrical segment surface which is preferably connected steplessly to the wedge surface. The lower guide body 72 forms at least the inner functional surface F2. Here, the functional surface F1 serves as an introduction aid when inserting the pump segment 40, and the opposite functional surface F2 serves as a hose guide element in order to center the pump segment PS relative to the pressure element, i.e. the pressure roller 20, when the peristaltic pump is in operation.

[0043] In the exemplary embodiment shown, the cross section of the guide bodies 70, 72 each has a center axis or axis of symmetry, wherein Figure 6 Only the symmetry axis SA70 of the guide body 70 is drawn. Figure 6 It can also be seen in FIG. 7 that the guide bodies 70 , 72 are additionally supported on the rocker arm 41 by means of a strut 76 following the axis of symmetry SA70 .

[0044] Overall, the upper guide body 70 together with the outer functional surface F1 is designed as an introduction aid for the pump segment PS, while the two guide bodies 70 , 72 together with their functional surfaces F2 serve as hose guiding elements.

[0045] The following working method is obtained with the help of this design, which is based on Figure 2 and 7A to 7D To describe:

[0046] From any rotational position, e.g. Fig. 7A Starting from the position of the rotor 10 shown in FIG. 1 , on which the inserted pump segment PS extends from the connection point PN to the connection point PP following the support surface 30 , the rotor 10 can be rotated manually by the user holding the rotor 10 in the free space 78 between the guide surfaces 46, 48. In this phase, the guide body 70 does not yet contact the pump segment PS.

[0047] Once the rotor reaches Figure 7B The rotational position (which is also Figure 2 ), the outer functional surface F1 of the guide body 70 slides onto the pump segment PS. Figure 6 As the rotor 10 continues to rotate, the functional surface F1 of the guide body 70 now continues to press the pump segment PS downward into the pump bed, so that the pump segment PS is finally captured by the functional surface F2 in the center relative to the symmetry plane ES, because the pump segment rests on the support surface 30. This function also continues when the support surface 30 is swept (see Figure 7C), so that ultimately the entire pump segment PS is centered relative to the pressure rollers in the pump bed 7.

[0048] Fig.7D The rotational position of the rotor 10 is shown when the guide body 70*, which is not involved in the insertion process and is offset by 180° from the guide body 70, encounters the pump segment PS which is already in the pump bed 7. In this phase, the guide bodies 70 and 72 approach the pump segment PS so that they guide the pump segment PS between the functional surfaces F2 like a funnel and thus center the pump segment relative to the pressure roller 20. This mode of action occurs every time the pressure roller is activated during the operation of the peristaltic pump, whereby the delivery volume of the peristaltic pump can be kept constant.

[0049] Preferably, the guide bodies 70 , 72 are formed from and / or coated with a material having sliding properties that minimize wear.

[0050] In the embodiment shown, the guide bodies 70, 72 are integrally mounted on the rocker arm 41, more precisely on the pivot bearing bores 50, 52. In order to produce the rocker arm 41, an injection molding method, such as a metal injection molding (MIM) method, can be used in this case, whereby it is even possible to produce the rocker arm 41 from a stainless steel material, such as a heat-resistant austenitic chromium-nickel steel (X15CrNiSi25-21), as it is known under the name 1.4841. This steel is particularly resistant to oxidation and it has been shown that the surface quality that can be achieved in the MIM method is sufficient to make the functional surfaces F1 and F2 sufficiently smooth without further processing in order to press the pump segment PS into the pump bed smoothly and without wear and to orient it centrally relative to the pressure roller.

[0051] Of course, deviations from the described embodiments are possible without departing from the essential idea of ​​the invention.

[0052] For example, it is also possible to construct the guide bodies 70, 72 as separate components and then connect these separate components to the rocker arm 41 to form an integral structural unit. The guide bodies 70, 72 do not have to be designed axially symmetrically to each other. The lower guide body 70 can have a cylindrical cross section, for example.

[0053] The rocker arm 41 with the integrated introduction aid and the hose guiding element can also be produced from very different materials and / or by a milling method.

[0054] In the above-described peristaltic pump, two extrusion elements are provided, which are arranged rigidly or at a fixed angle of 180° to each other in a relative position of 180°. However, it can also be provided that there are more than two extrusion elements and that these extrusion elements are designed to be positionable relative to each other in the direction of rotation at an angle. For this purpose, the extrusion elements can be arranged on a rotor arm, which can be designed to be pivotable relative to the rotor in the circumferential direction.

[0055] The pressing elements do not have to be designed as pressing rollers or pressure rollers, which advantageously roll on the fluid line in a material-protecting manner. Sliding shoes that slide on the hose section can also be provided.

[0056] The present invention therefore provides a peristaltic pump, in particular for conveying fluids in an apparatus for extracorporeal blood treatment, the peristaltic pump having a pump housing, a rotor rotatable about a rotor axis being accommodated in a pump bed of the pump housing, the rotor having at least two displacement elements offset from each other in the circumferential direction, and the pump housing having a support surface extending in an arc about the rotor axis and radially spaced from the rotor, the support surface being provided for supporting a hose segment, i.e. a pump segment, which can be introduced between the support surface and the rotor. For holding the displacement element, the rotor has a rocker arm pivotally and spring-loadedly fixed to the rotor, an introduction aid, by means of which the hose segment can be pressed during its insertion into the pump bed, and by means of which the hose segment can be oriented in the middle of the displacement element.

[0057] In order to make the threading process as simple as possible for the user with a simplified design and thereby to protect the hose section to be threaded into the peristaltic pump from damage to the greatest extent possible, both the introduction aid and the hose guide element are integrated into the rocker arm adjacent to the pressing element in the direction of rotation of the rotor.

Claims

1. A peristaltic pump, in particular for conveying fluid in an apparatus for extracorporeal blood treatment, the peristaltic pump having A pump housing (5), a rotor (10) rotatable about a rotor axis (A) being accommodated in a pump bed (7) of the pump housing, the rotor having at least two displacement elements (20) offset relative to one another in the circumferential direction, and the pump housing having a support surface (30) extending in an arc shape about the rotor axis (A) and radially spaced apart from the rotor (10), the support surface being provided for supporting a hose section (PS) which can be introduced between the support surface and the rotor (10), in, The rotor (10) The squeeze element (20) carries a rocker arm (41) which is pivotally and spring-loadedly fastened to the rotor (10), an introduction aid (70, F1), by means of which the hose section (PS) can be pressed during manual insertion into the pump bed (7), and a hose guide element (70, 72), by means of which the hose section (PS) can be oriented in the middle of the squeeze element (20), characterized in that Both the introduction aid (70, F1) and the hose guide element (70, 72, F2) are integrated into the rocker arm (41) adjacent to the pressing element (20) in the direction of rotation (D) of the rotor (10).

2. The peristaltic pump according to claim 1, It is characterized in that The rocker arm (41) is mounted on the rotor (10) by means of a pivot bearing (38), which is arranged offset in the direction of rotation relative to the displacement element (20), wherein the introduction aid (70, F1) and the hose guide element (70, 72, F2) are mounted on the pivot bearing (38).

3. The peristaltic pump according to claim 2, It is characterized in that The introduction aid (70, F1) is formed by a pin-shaped guide body (70), which extends from the pivot bearing (38) approximately in a radial direction away from the rotor axis (A) and which, when viewed in cross section, has approximately a rounded wedge shape pointing in the direction of rotation (D), which is inclined at an acute angle (WA) relative to the pump bed (7).

4. The peristaltic pump according to claim 3, It is characterized in that The guide body (70) has two functional surfaces (F1, F2), wherein the outer functional surface (F1) which is in front in the direction of rotation (D) of the rotor (10) and faces away from the center plane (ES) is designed as a rounded wedge surface, and the inner functional surface (F2) facing the center plane (ES) is formed by a cylindrical segment surface which is preferably continuously connected to the wedge surface.

5. The peristaltic pump according to claim 3 or 4, It is characterized in that The cross section of the guide body (70) has a central axis (SA70), wherein the guide body (70) is preferably additionally supported on the rocker arm (41) by means of a strut (76) following the central axis (SA70).

6. A peristaltic pump according to any one of claims 2 to 5, It is characterized in that The guide body (70) is preferably integrally mounted on the pivot bearing hole (50) of the rocker arm (41).

7. The peristaltic pump according to claim 6, It is characterized in that The rocker arm (41) is configured with a stop surface (54) for a compression spring (56) at its end section facing away from the pivot bearing eye (50, 52), wherein the pressure element (20) is arranged, for example rotatably supported, between the pivot bearing eye (50, 52) and the stop surface (54).

8. A peristaltic pump according to any one of claims 3 to 7, It is characterized in that A further second guide body (72) is assigned to the first guide body (70) which constructs the introduction aid (70, F1), and is constructed and oriented symmetrically to the first guide body (70) with respect to a horizontal plane (ES) parallel to the pump bed (7), so that the facing cylindrical segment surfaces (F2) of the two guide bodies (70, 72) constitute the functional surfaces of the hose guide element (70, 72, F2).

9. The peristaltic pump according to claim 8, It is characterized in that The horizontal plane (ES) is the symmetry plane of the rocker arm (41).

10. A peristaltic pump according to any one of claims 1 to 9, It is characterized in that At least the introduction aid (70, F1) and / or the hose guide element (70, 72, F2) are made of and / or coated with a material having sliding properties that minimize wear.

11. A peristaltic pump according to any one of claims 1 to 10, It is characterized in that The rocker arm (41) with the integrated introduction aid (70, F1) and the hose guide element (70, 72, F2) is designed as a one-piece component which is preferably produced by a metal injection molding (MIM) method.

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