Pumping device, single-use device and method for operating a pumping device

Abstract

A pumping device for conveying a fluid is proposed, having a disposable device and a reusable device, wherein the disposable device is designed to be inserted into the reusable device and comprises two pump units arranged in series, wherein each pump unit comprises a rotor for conveying the fluid, wherein each rotor is designed as a rotor of a bearingless electric motor and can be contactlessly magnetically suspended and contactlessly driven for rotation about an axial direction, wherein the reusable device is designed for insertion of the disposable device and comprises for each rotor a stator which forms with the rotor an electromagnetic rotary drive for rotating the rotor about the axial direction, wherein each stator is designed as a bearing and drive stator through which the rotor can be contactlessly magnetically driven and can be contactlessly magnetically suspended relative to the stator, and wherein for each stator an independent control device is provided.

Description

TECHNICAL FIELD

[0001] The present invention relates to a pumping device for conveying a fluid, to a single-use device for such a pumping device, and to a method for operating a pumping device. BACKGROUND

[0002] In biotechnological or medical-technological applications, pumps are often required through which very sensitive substances, such as blood or cell cultures or proteins, can be conveyed, whereby it is of great importance that these substances are damaged as little as possible by the pump. For this purpose, on the one hand, peristaltic pumps are known, and on the other hand, centrifugal pumps are known, in which a rotating rotor (impeller) with vanes acts on the fluid to be conveyed.

[0003] Centrifugal pumps are known which comprise an electromagnetic rotary drive which is designed and operated according to the principle of a bearingless motor. In this connection, the term "bearingless motor" refers to an electromagnetic rotary drive in which the rotor is completely magnetically suspended with respect to the stator, wherein no separate magnetic bearing is provided. For this purpose, the stator is designed as a bearing and drive stator, which is both the stator of the electric drive and the stator of the magnetic suspension. By means of the electrical windings of the stator, a rotating magnetic field can be generated which, on the one hand, exerts a torque on the rotor, which influences the rotation of the rotor, and which, on the other hand, exerts a shear force which can be set as desired on the rotor, so that the radial position of the rotor can be actively controlled or adjusted. Thus, three degrees of freedom of the rotor can be actively adjusted, i.e. its rotation and its radial position (two degrees of freedom). For the other three degrees of freedom, i.e. its position in the axial direction and its inclination with respect to a radial plane perpendicular to the desired axis of rotation (two degrees of freedom), the rotor is passively magnetically suspended or stabilized by magnetic resistance forces, i.e. it cannot be activated. The characteristic is the lack of a separate magnetic bearing, which has a completely magnetically suspended rotor, which gives the bearingless motor its name.

[0004] At the same time, bearingless motors have become sufficiently well known to the person skilled in the art and are used for many different applications. Some basic descriptions can be found, for example, in EP-A-0 860 046 and EP-A-0 819 330.

[0005] Centrifugal pumps designed according to the principle of a bearingless motor have proven themselves in a large number of applications.

[0006] Centrifugal pumps designed according to the principle of bearingless electric machines are particularly suitable for such applications due to the absence of mechanical bearings: in them, the very sensitive substances mentioned at the outset are conveyed, for example, as blood pumps, or as pumps in which very high requirements are made with regard to purity, for example, in the pharmaceutical industry or in the biotechnology industry, or also for applications in which abrasive or corrosive substances are conveyed, which would very quickly destroy mechanical bearings, for example, pumps for slurries or acidic fluids used in the semiconductor industry.

[0007] An example of such applications is extracorporeal membrane oxygenation (ECMO), in which blood is continuously conveyed through a membrane oxygenator, which replaces the gas exchange in the lungs, removes carbon dioxide from the blood and fills it with oxygen. In addition, there are machines that take over the function of the lungs during surgery as cardiopulmonary machines (CPB, extracorporeal circulation). In biotechnology, for example, pumps are required to circulate nutrient liquids through bioreactors or to move fluids through filter units in which the substrate to be produced is extracted.

[0008] In these applications, particularly in medical technology and biotechnology applications, redundancy must of course be provided, because if the pumping device fails, it must of course be ensured that the patient or the substance to be produced is not endangered. It is therefore common practice to keep a second, usually identical pumping device ready to replace the faulty pumping device and to take over its function if it fails.

[0009] In all these applications, centrifugal pumps designed according to the principle of bearingless electric machines have proven successful, particularly because no mechanical bearings are provided here, which can have a negative effect on the purity of the process.

[0010] A further advantage of the principle of bearingless electric machines is the design of the rotor as an integral rotor, which is both the rotor of the electromagnetic drive and the rotor of the centrifugal pump. In addition to the contactless magnetic levitation, the advantage here is a very compact and space-saving design.

[0011] In addition, the principle of the bearingless motor also allows the following centrifugal pump design: in which the rotor or the pump housing, which has the rotor arranged therein, can be separated from the stator very easily. This is a great advantage because in this way, for example, the pump housing, which has the rotor arranged therein, can be designed as a single-use component for single-use applications. Today, such single-use applications are often replacing processes in which, due to very high purity requirements, all those components that come into contact with the fluid to be treated in the process have to be cleaned and disinfected in a careful manner, for example, by means of steam sterilization. When designed for single use, those components that come into contact with the fluid to be treated are used exactly once and are then replaced by new, i.e. unused, single-use components for the next application.

[0012] When using centrifugal pumps for the transport of sensitive substances such as blood or other biological fluids, the problem arises of the interaction between the blades of the rotor and the fluid to be transported. In this respect, in particular two aspects can damage cells present in the fluid, for example red blood cells, namely the shear forces acting on the cells or other particles and the residence time of the shear forces, i.e. the time during which the particles are exposed to these shear forces. At the same time, it is known that the magnitude of the shear forces is the more important factor in relation to the damage in the transported fluid.

[0013] Therefore, starting from this prior art, it is the object of the present application to propose a pumping device which, on the one hand, is able to transport very sensitive fluids, for example fluids containing cells, with as little damage to the fluid as possible and, on the other hand, has redundancy. In addition, a single-use component for such a pumping device and a method for operating such a pumping device should be proposed.

[0014] The subject matter of the present application which meets these objects is described in detail in the following description. SUMMARY

[0015] According to the application, therefore, a pumping device for conveying a fluid is proposed, which has a single-use device designed for single use and has a reusable device designed for multiple use, wherein the single-use device is designed to be inserted into the reusable device and comprises two pump units arranged in series one after the other, wherein each pump unit comprises a rotor for conveying the fluid, wherein each rotor is designed as a rotor of a bearingless electric motor and can be contactlessly magnetically suspended and contactlessly driven for rotation about an axial direction, wherein the reusable device is designed for insertion of the single-use device and comprises for each rotor a stator which forms with the rotor an electromagnetic rotary drive for rotating the rotor about the axial direction, wherein each stator is designed as a bearing and drive stator through which the rotor can be contactlessly magnetically driven and can be contactlessly magnetically suspended relative to the stator, and wherein for each stator an independent control device is provided which is designed for independent activation of the respective stator.

[0016] The reusable device designed for multiple use is thus designed in such a way that the single-use device can be inserted into the reusable device, the reusable device and the single-use device can be assembled and separated very easily. Since the pumping device according to the application comprises two pump units arranged in series, in order for the pumping device to generate a predetermined pressure, the two rotors can be operated at a lower rotational speed than if the same pressure had to be generated with only one pump unit, i.e. with only one rotor. It is known that the damage to cells, for example red blood cells, contained in a biological fluid conveyed by a centrifugal pump increases disproportionately with the rotational speed of the centrifugal pump. The rotational speed at which a centrifugal pump is operated is a decisive factor for the magnitude of the shear forces to which the biological cells in the fluid are subjected. The magnitude of this shear force in turn is an essential factor responsible for the damage or destruction of the cells.

[0017] It is known that in a centrifugal pump the pressure generated, more precisely the pressure difference between the pressure at the inlet of the pump and the pressure at the outlet of the pump, is at least in very good approximation proportional to the square of the rotational speed. However, this means that if a pressure difference is to be generated with two identical pump units connected in series, the rotational speed for each pump unit can be reduced by a factor of 1 divided by the square root of 2 ), i.e. each of the two pump units is operated at approximately 0.71 times the rotational speed at which a single pump unit would have to be operated if it were to generate the same pressure difference. This reduction in the rotational speed significantly reduces the damage to cells in the fluid to be conveyed.

[0018] Furthermore, since each stator is provided with an independent control device, so that each stator can be activated independently, the pumping device according to the application enables thermal redundancy, so that it is not necessary to keep a replacement pumping device available. In the normal case, i.e. fault-free operation, the two pump units connected in series together produce the desired pressure difference. If one of the two pump units now fails, the rotational speed of the other pump unit is increased by a factor of . This thermal redundancy, which allows independent activation of each stator, is significantly advantageous, in particular in medical applications, such as blood pumping and biotechnological applications, such as cell culture.

[0019] According to a preferred embodiment, the single-use device has two cup-shaped protrusions, in each of which a rotor is arranged, and the reusable device has two recesses, each of which is designed to receive one of the cup-shaped protrusions. This embodiment enables particularly easy assembly and separation of the single-use device and the reusable device.

[0020] A preferred embodiment is that the reusable device is designed such that, in the operating state, the rotors of the single-use device each rotate around a rotational axis, which encloses an angle with the vertical which is different from zero, which is less than 90°. In this embodiment, in the operating state, the two pump units are then arranged one after the other in a plane, which is inclined to the horizontal and to the vertical. This embodiment is particularly advantageous for priming the pump units, since it is more effective in preventing air bubbles from adhering, as in a siphon, for example in the flow connection between the two pump units.

[0021] According to a preferred embodiment, each pump unit is configured as a radial pump unit. The first pump unit has a first inlet and a first outlet for a fluid, and the second pump unit has a second inlet and a second outlet for a fluid, wherein each inlet is designed such that the fluid flows from an axial direction to the respective rotor, and wherein each outlet is designed such that the fluid leaves the respective pump unit in a discharge direction, which is aligned perpendicular to the axial direction.

[0022] In a first embodiment, the disposable of the pumping device is designed such that the fluid is deflected between the first outlet and the second inlet by at least 90° and preferably by 90°. If this disposable is aligned such that the rotational axes of the pump units are aligned in the vertical direction (direction of gravity), the two pump units are arranged offset with respect to the axial direction. The fluid leaves the first pump unit in a discharge direction extending perpendicular to the axial direction, is then deflected by 90° and then flows through the second inlet of the second pump unit in the vertical direction.

[0023] In a second embodiment, the disposable of the pumping device is designed such that the fluid is deflected between the first outlet and the second inlet by a total of 270°. If this disposable is aligned such that the rotational axes of the pump units are aligned in the vertical direction (direction of gravity), the two pump units are arranged at the same height with respect to the vertical direction, i.e. next to each other. The fluid leaves the first pump unit in a discharge direction extending perpendicular to the vertical direction, is then first deflected by 90° upwards in the vertical direction, is then again deflected by 90° in a direction perpendicular to the vertical direction (horizontal direction), is then deflected by 90° downwards in the vertical direction and finally flows through the second inlet of the second pump unit in the vertical direction.

[0024] An advantageous measure is that in each case a separate power supply is provided for each stator, such that if one of the power supplies fails, one of the stators can still be supplied with power. Thus, each stator and the control device assigned to it and, if necessary, further components are also completely independent of the power supply, i.e. they can not only be activated, but also supplied with power completely independently of the state of another stator or stators.

[0025] As an advantageous option, a high-level control unit can be provided, which is signal-connected to all control devices for the stators.

[0026] A further advantageous option is that an emergency energy store is provided, from which energy can be supplied to each stator if the primary energy source for supplying the stators with power can no longer provide energy to one or all pump units.

[0027] For example, the primary energy source can be designed as a power supply unit that receives power from an external power supply system. For example, the emergency energy store can be designed as an accumulator or a battery and provides energy even if the power supply unit is not connected to the external power supply system or if the power supply unit is defective. For example, such an accumulator or such a battery is very advantageous when a patient is connected to the pumping device and has to be transported from one place to another.

[0028] Preferably, each power supply comprises both a primary energy source, which is designed as a power supply unit that can be connected to an external power supply system, and an accumulator or battery, which serves as an emergency energy store.

[0029] A further advantageous measure is that the single-use device and / or the reusable device comprise an identification element, with which the single-use device and the reusable device can exchange information with one another. In particular, each identification element can also be designed as an RFID (Radio Frequency Identification) or as a bar code, in particular as a two- or three-dimensional bar code.

[0030] Furthermore, the application also proposes a single-use device, which is designed for single use and for a pumping device designed according to the application.

[0031] The application also proposes a method for operating a pumping device designed according to the application, wherein a desired value for an operating parameter of the pumping device is predetermined for each control device, wherein an actual value for this operating parameter is determined by means of a sensor, and wherein the actual value is transmitted to each control device.

[0032] Preferably, the control devices exchange signals with one another, by means of which each control device can determine the function of the other pump unit.

[0033] A preferred operating parameter is the flow rate through the pumping device or the pressure differential generated by the pumping device.

[0034] An advantageous option is that the flow rate through the pumping device is determined by the rotational speed and the torque at which the rotor is driven.

[0035] Further advantageous measures and embodiments of the application are described in detail below. BRIEF DESCRIPTION OF DRAWINGS

[0036] In the following, the application will be explained in more detail on the basis of embodiments and on the basis of the drawings, both from the perspective of the equipment and from the perspective of the process engineering. In the schematic drawings (partly in cross section):

[0037] Figure 1 : Schematic cross-sectional illustration of a first embodiment of a pumping device according to the application in a cross section along the cross-sectional line I-I in Figure 2

[0038] Figure 2 : Schematic cross-sectional illustration of the first embodiment in a cross section along the cross-sectional line II-II in Figure 1

[0039] Figure 3 : Schematic cross-sectional illustration of the first embodiment in a cross section along the cross-sectional line III-III in Figure 4 ​​schematic cross-sectional view of the first variant for a single-use device in a cross-section along the section line III-III in Fig. 3,

[0040] Figure 4 : in a cross-section along the section line IV-IV in Fig. 4, Figure 3 schematic cross-sectional view of the first variant for a single-use device in a cross-section along the section line IV-IV in Fig. 4,

[0041] Figure 5 : in a cross-section along the section line V-V in Fig. 5, Figure 6 schematic cross-sectional view of the second embodiment of the pumping device according to the application in a cross-section along the section line V-V in Fig. 5,

[0042] Figure 6 : in a cross-section along the section line VI-VI in Fig. 6, Figure 5 schematic cross-sectional view of the second embodiment in a cross-section along the section line VI-VI in Fig. 6,

[0043] Figure 7 : in a cross-section along the section line VII-VII in Fig. 7, Figure 8 schematic cross-sectional view of the second variant for a single-use device in a cross-section along the section line VII-VII in Fig. 7,

[0044] Figure 8 : in a cross-section along the section line VIII-VIII in Fig. 8, Figure 7 schematic cross-sectional view of the second variant for a single-use device in a cross-section along the section line VIII-VIII in Fig. 8,

[0045] Figure 9 : in a cross-section similar to Fig. 9, Figure 5 schematic cross-sectional view of the third embodiment of the pumping device according to the application in a cross-section similar to Fig. 9,

[0046] Figure 10 : in a cross-section along the section line X-X in Fig. 10, Figure 11 schematic cross-sectional view of the fourth embodiment of the pumping device according to the application in a cross-section along the section line X-X in Fig. 10,

[0047] Figure 11 : in a cross-section along the section line XI-XI in Fig. 11, Figure 10 schematic cross-sectional view of the fourth embodiment of the pumping device according to the application in a cross-section along the section line XI-XI in Fig. 11,

[0048] Figure 12 : in a cross-section along the section line XII-XII in Fig. 12, Figure 13 schematic cross-sectional view of the third variant for a single-use device in a cross-section along the section line XII-XII in Fig. 12,

[0049] Figure 13 : in a cross-section along the section line XIII-XIII in Fig. 13, Figure 12 schematic cross-sectional view of the third variant for a single-use device in a cross-section along the section line XIII-XIII in Fig. 13,

[0050] Figure 14 : a schematic cross-sectional view of a third variant of a disposable device in a cross-section taken along a cross-sectional line XIV-XIV in Figure 12

[0051] Figure 15 : a symbolic representation of an embodiment of a pumping device according to the present application, to explain an embodiment of a method according to the present application, for operating a pumping device according to the present application,

[0052] Figure 16 : a flow chart for an embodiment of a method according to the present application, and

[0053] Figures 17-20 : different variants of an embodiment of a method according to the present application, each illustrated in a similar way as Figure 15 DETAILED DESCRIPTION

[0054] In the following description of the present application based on embodiments, examples and variants thereof, identical parts or functionally equivalent parts are designated by the same reference signs throughout. It is understood that the explanations with respect to examples of embodiments or a specific embodiment or a specific variant are also applied in the same way or in a similar same way to other embodiments, examples and variants thereof. This means that only the differences to the above-described embodiments, examples or variants thereof will be discussed in more detail.

[0055] Figure 1 A first embodiment of a pumping device according to the present application is illustrated in a schematic cross-sectional view, which is indicated as a whole by the reference sign 1. For a better understanding, Figure 2 A schematic cross-sectional view of the first embodiment of the pumping device 1 according to the present application is still illustrated, wherein the cross-section is made along a cross-sectional line II-II in Figure 2 In Figure 2 , the cross-sectional line I-I is drawn for the cross-sectional view illustrated in Figure 1 .

[0056] To ensure the purity or sterility of those components which come into contact with the fluid to be conveyed, e.g. blood or another biological fluid, the pumping device 1 has a disposable device, which is designated as a whole by the reference sign 2 and is designed for one-off use, and a reusable device, which is designated as a whole by the reference sign 3 and is designed for permanent use, i.e. multiple use. The disposable device 2 comprises those components which come into contact with the fluid to be conveyed during the operation of the pumping device 1.

[0057] ​​The terms "single-use device" and other components having the component "single-use" (e.g. single-use component, single-use assembly, etc.) refer to those components or parts which are designed for a single use, i.e. which can only be used as intended once and then disposed of. For a new application, then a new, previously unused single-use component has to be inserted. Thus, a fundamental aspect when constructing or designing the single-use device 2 is that the single-use device 2 can be produced as simply and economically as possible and that this results in low costs. Another fundamental aspect is that the single-use device 2 can be assembled with and detached from the reusable device 3 as easily as possible. Thus, the single-use device 2 should be able to be replaced very easily without high assembly effort. It is particularly preferred that the single-use device 2 should be able to be assembled with and detached from the reusable device 3 without the use of tools.

[0058] For this purpose, the single-use device 2 is designed to be inserted into the reusable device 3 and the reusable device 3 is designed to receive the single-use device 2, i.e. in such a way that the single-use device 2 can be inserted into the reusable device 3.

[0059] The single-use device 2 is designed according to a first variant, which is represented in two schematic sectional views in Figure 3 and Figure 4 . Figure 3 A first variant of the single-use device 2 is shown in cross section along the sectional line III-III in Figure 4 , and Figure 4 a second variant of the single-use device 2 is shown in cross section along the sectional line IV-IV in Figure 3 .

[0060] The single-use device 2 comprises two pump units, i.e. a first pump unit 21 and a second pump unit 22. The first pump unit 21 comprises a first inlet 211 and a first outlet 212 for the fluid to be conveyed. The second pump unit 22 comprises a second inlet 221 and a second outlet 222 for the fluid to be conveyed. The two pump units 21, 22 are arranged in series or one after the other, i.e. the first outlet 212 is flow-connected to the second inlet 221 by means of a connecting channel 23. Thus, in the operating state, the fluid flows through the first inlet 211 into the first pump unit 21, flows through the first pump unit 21 and leaves the first pump unit 21 through the first outlet 212. From there, the fluid passes through the connecting channel 23 to the second inlet 221, flows through the second pump unit 22 and leaves the second pump unit 22 through the second outlet 222, as is represented by the two arrows without reference symbols in Figure 1 .

[0061] Each pump unit 21, 22 comprises in each case a pump housing 213 or 223 (Fig. 1) Figure 3 ), in which in each case a rotor 214 or 224 for conveying fluid is provided, which forms the respective impeller of the pump unit 21. Each rotor 214, 224 is designed at the same time as a rotor 214, 224 of an electromagnetic rotary drive, each rotor being constructed according to the principle of a bearingless motor, which will be explained further below. For this purpose, each rotor 214, 224 comprises in each case a magnetically effective core 215 or 225, which can be produced for example as a permanent magnet ring or also as a ring of a soft magnetic material, for example iron. As a rule, this magnetically effective core 215 or 225 is completely covered or encapsulated by a sheath, which is preferably made of plastic. Then, in each case, an impeller 216 or 226 is arranged on this sheath, which acts on the fluid to be conveyed with a plurality of blades.

[0062] Preferably, each pump unit 21, 22 is designed as a radial centrifugal pump, in which the respective rotor 214, 215 rotates about a rotational axis Al or A2. The fluid flows in the direction of the respective rotational axis Al or A2 to the respective rotor 214, 224 and deflects the fluid in a discharge direction D (Fig. 1) Figure 4 ) perpendicular to the respective rotational axis Al or A2.

[0063] Preferably, but not necessarily, the two pump units 21, 22 are designed identically at least with respect to their hydraulics. It is particularly preferred that the rotational axes Al and A2 are parallel to one another. This common direction is designated hereinafter as axial direction A, both parallel rotational axes Al, A2 extending in this common direction. The direction perpendicular thereto is designated as radial direction.

[0064] Furthermore, it is preferred that the two pump units 21, 22 are rigidly connected to one another by a connecting channel 23, so that the two pump units 21, 22 and the connecting channel 23 form a structural unit, which can be inserted as a whole into the reusable device 3.

[0065] The longitudinal direction of the connecting channel 23 determines the discharge direction D (Fig. 1) Figure 4 ) in which the fluid leaves the first pump unit 21. The connecting channel 23 is aligned such that the discharge direction D is perpendicular to the axial direction A on the one hand and forms an angle different from 0° and 90° with an imaginary shortest connecting line M between the two rotational axes Al and A2 on the other hand. In the illustration in Figure 4 , the connecting line M lies on the section line III-III.

[0066] As is particularly apparent in Figure 1 and Figure 3As can be seen, in the first variant of the disposable device 2, the connecting channel 23 is designed such that the fluid is deflected 90° relative to the axial direction A between the first outlet 212 and the second inlet 221. The connecting channel 23 extends downstream of the first outlet 212, initially perpendicular to the axial direction A, such that the discharge direction D is perpendicular to the axial direction A. Subsequently, the connecting channel 23 bends downwards by 90°, whereby "below" refers to... Figure 1 neutralization Figure 3 The illustration shows fluid flowing through the second inlet 221 in the axial direction A. This embodiment has the following results: Figure 1 In the usage position indicated in the figure, the rotation axes A1 and A2 of pump units 21 and 22 are aligned in the vertical direction (gravity direction), and the two pump units 21 and 22 are arranged to be offset relative to the vertical direction.

[0067] Each pump unit 21, 22 has a pot-shaped or cup-shaped protrusion 217 or 227, which in each case is formed by a corresponding pump housing 213 or 223. Each rotor 214, 224 is arranged in the associated pump housing 213 or 223 such that at least the magnetically effective core 215 or 225 of the corresponding rotor 214, 224 is arranged in the corresponding cup-shaped protrusion 217 or 227.

[0068] Reusable device 3 ( Figure 1 The device includes a stator housing 35 in which two stators, namely a first stator 31 and a second stator 32, are disposed for interaction with one of the rotors 214 or 224. The reusable device 3 further includes two basin-shaped or cup-shaped recesses 33 or 34 disposed in the stator housing 35, and they are sized and arranged such that each of the cup-shaped recesses 33, 34 can, in each case, receive and surround one of the cup-shaped protrusions 217, 227 of the disposable device 2. The dimensions of each recess 33, 34 and each protrusion 217, 227 are matched to each other in such a way that each recess 33, 34 tightly surrounds one of the protrusions 217, 227 in the assembled state, and its housing surface abuts against the housing surface of the corresponding protrusion 217, 227.

[0069] Two stators 31, 32 are arranged around one of the grooves 33 or 34, and surround the respective grooves 33, 34 as closely as possible. Each stator 31, 32 is arranged such that, in the assembled state of the pumping device 1, each of the magnetically active cores 215, 225 is surrounded by the corresponding one of the stators 31, 32, or by the stator pole of the stator 31 or 32, thereby providing the best possible magnetic interaction between the respective stator 31, 32 and the respective magnetically active core 215, 225.

[0070] The embodiment with the protrusions 217, 227 in the single-use device 2 and the recesses 33, 34 in the reusable device 3 enables a particularly easy connection or separation of the single-use device 2 and the reusable device 3. The two protrusions 217, 227 are inserted into the two recesses 33, 34 in a simple manner and the pumping device 1 is ready for operation, the two protrusions 217, 227 having the rotors 214, 224 arranged therein. In the same simple manner, the two protrusions 217, 227 can be pulled out of the recesses 33, 34, thus separating the single-use device 2 from the reusable device 3. Of course, safety elements such as a click connection can be provided to prevent an accidental separation of the single-use device 2 and the reusable device 3.

[0071] As already mentioned, the two rotors 214, 224 and the two stators 31, 32 are designed such that the first stator 31 and the first rotor 214 and the second stator 32 and the second rotor 224 form an electromagnetic rotary drive which is designed as a bearingless electric motor.

[0072] For this purpose, each stator 31, 32 is designed as a bearing and drive stator through which the respective rotor 214, 224 can be driven contactlessly magnetically for rotation about the respective rotation axis Al, A2 and can be magnetically suspended without contact with respect to the stator 31, 32.

[0073] Since the two rotation axes Al, A2 are parallel, in the following reference will be made to the axial direction A.

[0074] The magnetically effective core 215 or 225 of the rotor 214 or 224, which can be designed in the form of a circular disk or a circular cylinder or a ring, refers to the region of the rotor 214, 224 which interacts with the respective stator 31, 32 for forming a torque and for generating a magnetic bearing force. Depending on the design, the magnetically effective core 215, 225 can comprise one or more permanent magnets. As an alternative, it is also possible to design the magnetically effective core 215, 225 without permanent magnets, for example as a reluctance rotor. In this case, the magnetically effective core 215, 225 is at least partially composed of a ferromagnetic material, for example iron.

[0075] For example, the respective rotary drive with the first rotor 214 and the first stator 31 or with the second rotor 224 and the second stator 32 is designed as a so-called temple motor.

[0076] The characteristic features as an embodiment of a temple motor are characterized in that the stators 31, 32 comprise a plurality of individual coil cores, each coil core comprising a bar-shaped longitudinal leg which extends in the axial direction A from a first end to a second end, wherein all first ends are connected by a yoke. Furthermore, each coil core comprises a transverse leg which is arranged at the second end of the respective longitudinal leg and which extends in the radial direction, i.e. perpendicular to the axial direction A and thus to the respective longitudinal leg. Each transverse leg extends in the radial direction inwards, i.e. towards the respective rotor 214, 224. Thus, each coil core has an L-shaped design, wherein the longitudinal legs each form the long leg of the L which extends in the axial direction A and the transverse leg which extends perpendicular to the longitudinal leg in the radial direction towards the rotor 214, 224 forms the short leg of the L.

[0077] The radially inner end of the transverse leg each forms a stator pole. The stator poles are arranged in an annular shape around the respective recess 33, 34, with the rotor 214 or 224 located inside. In the operating state, the stator poles and the magnetically active core 215 or 225 are at the same level with respect to the axial direction A if the rotor 214, 224 is not deflected from its nominal position.

[0078] The parallel longitudinal legs of the coil cores which all extend parallel to the axial direction A and surround the rotor 214 or 224 give the temple motor its name, as these parallel longitudinal legs remind one of the columns of a temple.

[0079] Each stator 31, 32 further comprises a plurality of windings for generating an electromagnetic rotating field by which the respective rotor 214, 224 can be magnetically driven contactlessly and magnetically suspended contactlessly with respect to the stator 31 or 32. For example, the windings are designed as individual coils, wherein one coil is provided on each of the longitudinal legs of the stator 31, 32. Each coil is arranged around the respective longitudinal leg such that in each case the coil axis is parallel to the axial direction A.

[0080] Each temple motor is designed according to the principle of a bearingless motor. This means that during operation of the pumping device 1 the respective magnetically active core 215, 225 of the rotor 214, 224 interacts with the respective stator 31, 32 according to the above-mentioned principle of a bearingless motor, in which the respective rotor 214, 224 can be magnetically driven contactlessly and magnetically suspended contactlessly with respect to the respective stator 31, 32.

[0081] At the same time, the principles of bearingless electric machines are well known to the person skilled in the art, so that a more detailed description of their functioning is no longer required. The principles of bearingless electric machines mean that the rotors 214, 224 can be magnetically driven and magnetically suspended, wherein the stators 31, 32 are designed as bearing and drive stators, which are both stators of an electric drive and stators of a magnetic suspension. For this purpose, the stators 31 or 32 comprise windings, by means of which both the drive function and the bearing function are implemented in each case. By means of the windings, an electromagnetic rotating field can be generated, which on the one hand exerts a torque on the magnetically effective cores 215, 225 of the rotors 214, 224, which leads to a rotation thereof about the axial direction A, and which on the other hand exerts an arbitrarily settable shear force on the magnetically effective cores 215, 225 of the rotors 214, 224, so that their radial position, i.e. their position in a radial plane perpendicular to the axial direction A, can be actively controlled or adjusted. In the case of bearingless electric machines, in contrast to conventional magnetic bearings, the magnetic suspension and the drive of the electric machine are achieved via an electromagnetic rotating field, which exerts a torque and a settable shear force on the magnetically effective cores of the rotors. The rotating field required for this can either be generated by different coils or can be generated by a mathematical superposition of the required magnetic fluxes and then resort to a single coil system. It is therefore not possible in the case of bearingless electric machines to divide the electromagnetic flux generated by the windings of the stators 31, 32 into an electromagnetic flux which only provides the drive of the rotors 214, 224 and an electromagnetic flux which only achieves the magnetic suspension of the rotors 214, 224.

[0082] According to the principles of bearingless electric machines, at least three degrees of freedom of the rotors 214, 224, i.e. their position in the radial plane and their rotation about the axial direction A, can be actively adjusted. With regard to their axial deflection in the axial direction A, the magnetically effective cores 215, 225 of the rotors 214, 224 are passively magnetically stabilized by a magnetic resistance, i.e. it cannot be activated. With regard to the remaining two degrees of freedom, i.e. the tilting relative to the radial plane perpendicular to the rotational axis A1, A2, the rotors 214, 224 are also passively magnetically stabilized. Thus, by the interaction of the magnetically effective cores 215, 225 with the stators 31, 32, the rotors 214, 224 are passively magnetically suspended or passively magnetically stabilized in the axial direction A and against tilting (three degrees of freedom in total) and actively magnetically suspended in the radial plane (two degrees of freedom). In this way, the respective rotor 214, 224 can be driven contactlessly magnetically for rotation about the respective rotational axis A1, A2 and can be contactlessly magnetically suspended relative to the respective stator 31, 32.

[0083] A substantial aspect of the pumping device 1 according to the present application is that for each stator 31, 32 an independent control device 41, 42 is provided, i.e. a first control device 41 for the first stator 31 and a second control device 42 for the second stator 32. Each control device 41, 42 is designed such that an independent activation of the respective stator 31, 32 is possible.

[0084] Thus, in principle, the first control device 41 does not need any information from the second control device 42 in order to operate the first stator 31 and the first rotor 214 according to the principle of a bearingless electric machine. Conversely, the second control device 42 does not need any information from the first control device 41 in order to operate the second stator 32 and the second rotor 224 according to the principle of a bearingless electric machine.

[0085] This means that if one of the control devices 41 or 42 fails, the pumping device 1 is still in operation, since the operation of the pumping device 1 can be maintained by the other control device 42 or 41. Thus, the pumping device 1 according to the present application can be designed as hot redundant.

[0086] Preferably, according to the illustration in Figure 1 Each control device 41 or 42 is designed as an electronic board arranged below the respective stator 31, 32 and fixed to the respective stator 31, 32. Each electronic board comprises all components necessary for the operation of the respective bearingless electric machine, such as power electronics for activating the windings, and the necessary evaluation, regulation and activation components.

[0087] Furthermore, for each control device 41, 42, a power supply 51, 52 is provided, which supplies the respective control device 41, 42 with power, preferably with electrical power, i.e. a first power supply 51, which supplies the first control device 41 with power, and a second power supply 52, which supplies the second control device 42 with power. The first power supply 51 is connected to the first control unit 41 via a first power supply line 101, and the second power supply 52 is connected to the second control unit 42 via a second power supply line 102.

[0088] Preferably, the power supplies 51, 52 are arranged in the stator housing 35.

[0089] Each power supply 51, 52 comprises a primary energy source 511, 521 and an emergency energy store 512, 522. For example, in each case, the primary energy source 511, 521 can be designed as a power supply unit, which receives electrical power from an external power supply system. For example, in each case, the emergency energy store 512, 522 can be designed as an accumulator or a battery and provides energy even if the power supply unit is not connected to the external power supply system or if the power supply unit fails. Such an accumulator or such a battery is very advantageous, for example, when a patient is connected to the pumping device 1 and has to be transported from one place to another.

[0090] In the case of other embodiments, only one common power supply is provided, which provides electrical energy to both control units 41, 42. Even in such embodiments, the common energy supply comprises both the main energy source, which is designed as a power supply unit that can be connected to an external power supply system, and the accumulator or battery as an emergency energy store.

[0091] The pumping device 1 further comprises at least one sensor 6 by means of which an operating parameter of the pumping device 1 can be determined. For example, the sensor 6 is a flow sensor 61 by means of which the flow rate of the fluid through the pumping device 1 can be determined. For example, the flow sensor 61, which is designed as an ultrasonic flow measuring device, can be arranged at or near the second outlet 222. It is possible that the flow sensor 61 or more generally the sensor 6 is part of the reusable device 3. Furthermore, it is possible that the flow sensor 61 or more generally the sensor 6 is part of the disposable device 2.

[0092] The sensor 6 is connected to the first control device 41 by means of a first signal connection 601 and to the second control device 42 by means of a second signal connection 602. This also ensures that the control devices 41, 42 are independent of one another, since each control device 41, 42 receives the signal from the sensor 6 independently of the other control device 42, 41.

[0093] Preferably, a communication connection 12 is provided via which the two control devices 41 and 42 can exchange signals or information with one another. For example, this communication connection 12 can be used so that each control unit 41, 42 can check the functionality of the other control unit 42, 41 or of the other pump unit 22, 21.

[0094] The disposable device 2, apart from the magnetically active core 215, 225, is preferably made of one or more plastics. In particular, the pump housing 213, 223, the inlet 211, 221, the outlet 212, 222, the connecting channel 23, the impeller 216, 226, the protrusion 217, 227 and the sheath of the magnetically active core 215, 225 are made of plastic. Of course, not all components of the disposable device 2 have to be made of the same plastic.

[0095] The selection of a suitable plastic naturally depends on the respective application. Suitable plastics are, for example: polyethylene (PE), polypropylene (PP), low-density polyethylene (LDPE), ultra-low-density polyethylene (ULDPE), ethylene vinyl acetate (EVA), polyethylene terephthalate (PET), polyvinyl chloride (PVC), polyvinylidene fluoride (PVDF), acrylonitrile butadiene styrene (ABS), polyurethane (PU), polyacrylic acid, polycarbonate (PC), silicone.

[0096] In the following text, based on Figures 5-8 A second embodiment of the pumping device 1 according to the invention is explained, which illustrates a second variant for the single-use device 2. As already stated, the differences from the first embodiment and the first variant will be discussed in more detail only.

[0097] Figure 5 With similar Figure 1 The illustration shows along Figure 6 A schematic cross-sectional view of the second embodiment of the pumping device 1 according to the present invention, showing the cross-section VV of the cross-section line. However, in Figure 5 The diagrams of the power supplies 51, 52 and various connections in the stator housing 35 have been omitted because they are designed in a manner similar to the first embodiment.

[0098] Figure 6 With similar Figure 2 The illustration shows along Figure 5 A schematic cross-sectional view of the second embodiment of the pumping device 1 according to the present invention, in the section of section line VI-VI. Figure 7 With similar Figure 3 The illustration shows along Figure 8 A schematic cross-sectional view of the second variant of the single-use device 2 in the section of section line VII-VII. Figure 8 With similar Figure 4 The illustration shows along Figure 7 A schematic cross-sectional view of the second variant of the single-use device 2 in the cross-section of section line VIII-VIII.

[0099] In a second variant of the disposable device 2, a disposable housing 28 is provided, in which pump units 21 and 22 are arranged. For example, the disposable housing 28 forms a box, which, as a disposable component, can be inserted into or detached from the reusable device 3 in a particularly simple manner.

[0100] For example, especially in Figure 5 and Figure 7 As can be seen, in the second variant of the disposable device 2, the connecting channel 23 is designed such that the fluid is deflected a total of 270° relative to the axial direction A between the first outlet 212 and the second inlet 221. The connecting channel 23 is essentially designed to be U-shaped. The connecting channel 23 first extends perpendicularly to the axial direction A downstream of the first outlet 212, such that the discharge direction D ( Figure 8 ( ) Perpendicular to the axial direction A. Then, connecting channel 23 bends upwards by 90°, where "above" refers to... Figure 5 neutralization Figure 7The diagram in the image shows this. Then, connecting channel 23 bends 90° to the right, where "right" refers to... Figure 5 neutralization Figure 7 As illustrated in the diagram, connecting channel 23 is once again perpendicular to the axial direction A. Finally, connecting channel 23 bends downwards by 90°, where "downwards" refers to... Figure 5 neutralization Figure 7 The illustration shows fluid flowing through the second inlet 221 in the axial direction A. This embodiment has the following results: Figure 5 In the usage position shown, the rotation axes A1 and A2 of pump units 21 and 22 are aligned in the vertical direction (gravity direction), and the two pump units 21 and 22 are arranged at the same height relative to the vertical direction, that is, adjacent to each other.

[0101] The reusable device 3 is suitable for this embodiment of the disposable device 2.

[0102] Figure 9 It shows that in relation to Figure 5 A schematic cross-sectional view of a third embodiment of the pumping device 1 according to the invention, in a similar cross-section. The third embodiment of the pumping device 1 according to the invention includes a disposable device 2 designed according to a second variant of the disposable device 2. It is understood that the third embodiment of the pumping device 1 according to the invention may also be arranged in a similar manner to the disposable device 2, which is designed according to a first variant for the disposable device 2.

[0103] The substantial difference from the previously described embodiments lies in the fact that, in the third embodiment of the pumping device 1 according to the invention, the reusable device 3 is designed such that the rotors 214 and 224 of the disposable device 2 rotate about rotation axes A1 and A2 respectively in the operating state, wherein rotation axes A1 and A2 form an angle with the vertical line that is different from zero degrees, said angle being less than 90°. This means that, in the operating state, the two rotation axes A1 and A2 are inclined relative to the vertical line at an angle different from zero degrees and 90°. The vertical line corresponds to the vertical direction, that is, the direction in which gravity acts.

[0104] With this embodiment, it is particularly easy to prevent gas bubbles (e.g., air bubbles) from adhering to the connection channel 23 during the preparation of the pumping device 1, which could cause considerable damage to the patient connected to the pumping device 1 during operation. For example, the adhesion of gas bubbles (as is desired in a siphon tube) is effectively prevented by the inclined positions of the two pump units 21, 22 relative to the vertical and horizontal directions.

[0105] exist Figures 10 to 14In the following, a fourth embodiment of the pumping device 1 according to the present application is explained, which has a third variant for the single-use device 2. Here, too, only the differences to the previously described embodiments and variants are discussed in more detail.

[0106] It is understood that the fourth embodiment of the pumping device 1 according to the present application can also be provided with a single-use device 2 in a similarly identical manner, which is designed according to the first or second variant for the single-use device 2.

[0107] Figure 10 A schematic cross-sectional illustration of the fourth embodiment of the pumping device 1 according to the present application in a cross-section along the cross-sectional line X-X in Figure 1 is shown in a similar manner to the illustration in Figure 11 . Figure 11 A schematic cross-sectional illustration of the fourth embodiment of the pumping device 1 according to the present application in a cross-section along the cross-sectional line XI-XI in Figure 6 is shown in a similar manner to the illustration in Figure 10 . Figure 12 A schematic cross-sectional illustration of the third variant for the single-use device 2 in a cross-section along the cross-sectional line VII-VII in Figure 7 is shown in a similar manner to the illustration in Figure 13 . Figure 13 A schematic cross-sectional illustration of the third variant for the single-use device 2 is shown in a cross-section along the cross-sectional line XIII-XIII in Figure 12 , and Figure 14 A schematic cross-sectional illustration of the third variant for the single-use device 2 is shown in a cross-section along the cross-sectional line XIV-XIV in Figure 12 .

[0108] In the fourth embodiment of the pumping device 1 according to the present application, the reusable device 3 is designed in a similar manner to the third embodiment, such that in the operating state the rotors 214, 224 of the single-use device 2 each rotate about a rotation axis Al, A2, wherein the rotation axes Al and A2 enclose an angle with the perpendicular which is different from zero degrees and which is smaller than 90°. This means that in the operating state the two rotation axes Al and A2 are inclined at an angle which is different from zero and 90° with respect to the perpendicular.

[0109] The single-use device 2 is designed according to the third variant, in which the flow of the fluid in the single-use device 2 is similar to the flow of the fluid in the second variant of the single-use device 2. It is of course also possible that the third variant of the single-use device 2 is designed in a similarly identical manner, such that the flow of the fluid takes place in a similar manner to the first variant, i.e. such that the fluid is deflected by 90° with respect to the axial direction A only between the first outlet 212 and the second inlet 221.

[0110] In a third variant, the single-use device 2 comprises three components 291, 292, 293, each of which is produced separately and then joined together in a joining process. The three components 291, 292, 293 are designed such that their respective boundary surfaces are aligned perpendicular to the axial direction A. The first component 291 comprises two protrusions 217, 227 through which the single-use device 2 can be inserted into the reusable device 3. The second component 292 comprises the regions which are adjacent to the first component 291 with respect to the axial direction A and which define the cavities upwards into which the two rotors 214 and 224 are arranged. Here, "upwards" means in the direction of the arrow A. Figure 12 The third component 293 forms the regions which define the single-use device 2 on the side which faces away from the reusable device 3 with respect to the axial direction A and which comprise the first inlet 211 and the component of the connecting channel 23.

[0111] From a manufacturing perspective, this embodiment is particularly advantageous. Each of the components 291, 292, 293 can be manufactured in a simple manner, preferably by means of an injection-moulding process, and the three components 291, 292, 293 are subsequently joined together firmly.

[0112] In Figure 13 and Figure 14 , the first component 291 and the second component 292 are illustrated. In these cross-sectional illustrations, the cross-section is made perpendicular to the axial direction in the boundary surface between the first component 291 and the second component 292 ( Figure 13 ) or in the boundary surface between the second component 292 and the third component 293 ( Figure 14 ). The position of the cross-section is illustrated in Figure 12 . This means that Figure 13 a plan view is shown on the first component 291 and Figure 14 a plan view is shown on the second component 292, each from the axial direction A.

[0113] As already mentioned, each of the three components 291, 292, 293 is preferably an injection-molded component. In order to manufacture the single-use device 2, the following steps are preferred: The three components 291, 292, 293 are made from plastic by means of an injection-molding process. Subsequently, in each case, the rotor 214 or 224 is inserted into the two protrusions 217, 227 of the first component 291. Then, the second component 292 is placed on the first component 291 and is firmly and sealingly connected to the first component 291 in a joining process. This joining process can be, for example, a bonding process, for example, by means of an adhesive which can be cured with ultraviolet radiation. Furthermore, the joining process can be a welding process, for example, infrared welding or laser welding or ultrasonic welding. The third component 293 is connected to the second component 292 in a similarly identical manner. In this variant, the connecting channel 23 and the pump housing 213, 223 are thus each formed by a cavity which is provided in the three components 291, 292, 293. Of course, it is also possible that all components 291, 292, 293 are placed on top of one another first and only then, in a welding or bonding process, the three components 291, 292, 293 are firmly connected.

[0114] As can be seen in particular in Figure 12 , a measuring channel 7 can be provided in the single-use device 2 or several measuring channels can also be provided which extend from the outside of the single-use device 2 to one of the two inlets 211, 221 or to one of the outlets 212, 222. Sensors (not shown) can be arranged in such a measuring channel with which operating parameters, for example, pressure or flow through the pumping device 1, can be determined.

[0115] In a fourth embodiment of the pumping device 1 according to the application, a high-level control unit 40 is further provided in the stator housing 35 Figure 10 . Of course, such a high-level control unit 40 can also be provided in the previously described embodiments.

[0116] This high-level control unit 40 is signal-connected to the first control device 41 via a first connection 401 and to the second control device 42 via a second signal connection 402, so that the high-level control unit 40 can exchange signals or information with both control devices 41, 42.

[0117] Furthermore, the single-use device 2 comprises an identification element 81 with which the single-use device 2 can identify itself on the reusable device 3. The identification element 81 contains specific data, in particular for the single-use device 2, for example, calibration data, so that the single-use device 2 can be recognized by the reusable device 3 and the specific properties of the respective single-use device 2 can be transmitted to the reusable device 3.

[0118] To this end, the reusable device 3 preferably comprises an identification element 82 which is designed in such a way that it can identify the respective single-use device 2 or its properties via an interaction with the identification element 81.

[0119] Preferably, both the identification element 81 and the identification element 82 are each designed as an RFID (Radio Frequency Identification) element. In other embodiments, the identification element 81 and / or the identification element 82 can comprise a barcode, in particular a two- or three-dimensional barcode.

[0120] The identification element 82 is signal-connected to the high-level control unit 40 via an identification connection, so that the high-level control unit 40 can receive specific data, for example calibration data, from the single-use device 2 inserted in the reusable device 3 in each case and / or can transmit data to this single-use device 2.

[0121] Furthermore, two pressure sensors 621 and 622 are provided, wherein the first pressure sensor 621 is arranged in such a way that it can be used to determine the pressure of the fluid at the first inlet 211 and the second pressure sensor 622 is arranged in such a way that it can be used to determine the pressure at the second outlet 222. Thus, the pressure difference generated by the pumping device 1 can be determined by means of the two pressure sensors 621 and 622.

[0122] The two pressure sensors 621 and 622 are signal-connected to the high-level control unit 40 via connections 611 and 612. In addition, or if no high-level control unit 40 is provided, the pressure sensors 621 and 622 can be signal-connected to any of the control units 41 and 42. This is Figure 10 In the figure only the pressure sensor 622 at the second outlet 222 is illustrated with the dashed connections 623 and 624.

[0123] The third part 293 can have a protrusion 294 or several protrusions 294 at its end facing the second part 292, for example one protrusion 294 at each corner, which are designed to interact with holding elements 394 on the surface of the stator housing 35 (see Figure 11 ). Preferably, the protrusions 294 on the single-use device 2 interact in the form of a snap connection with the holding elements 394 on the reusable device 3, which prevents an accidental separation of the single-use device 2 and the reusable device 3.

[0124] In the following, the method according to the application, which is used to operate the pumping device 1 according to the application, is now discussed in more detail. In this respect, the pumping device 1 according to the application can be designed according to any of the preceding embodiments or variants.

[0125] In the method according to the application, the desired value for the operating parameter of the pumping device 1 is predetermined for each control device 41, 42. The actual value for this operating parameter is determined by means of a sensor, and the actual value is transmitted to each control device 41, 42.

[0126] Figure 15 An embodiment of the pumping device 1 according to the application is shown in a symbolic diagram, which has two pump units 21, 22, has two control devices 41, 42 and has a communication connection 12 between the two control devices 41, 42. Furthermore, the first connection 43 and the second connection 44 are shown symbolically in dashed lines. The first connection 43 illustrates the communication of the first control device 41 with the first pump unit 21, and the second connection illustrates the communication of the second control device 42 with the second pump unit 22.

[0127] In principle, the method according to the application is based on the fact that, for a predetermined pressure difference to be produced by the pumping device 1, two pump units 21, 22 are used in normal, i.e. fault-free, operation in series. In doing so, the rotational speed for each of the two pump units 21, 22 can be reduced by a factor of compared to the case when only one pump unit 21 or 22 is used to produce the same pressure difference. This reduction in rotational speed results in a significant reduction in the shear forces acting on the fluid to be pumped in the pump units 21, 22. This is a great advantage, in particular when biological substances are being conveyed which include cells or other sensitive substances, such as blood.

[0128] If now, for whatever reason, one of the two pump units 21, 22 or control units 41, 42 fails, the rotational speed of the other pump unit 22 or 21 is increased by a factor of so that the desired pressure difference is now produced by only one remaining pump unit 22 or 21. The possibility of this hot redundancy design is a great advantage, in particular for medical applications, such as pumping blood, or for biotechnological applications, such as cell culture.

[0129] In Figure 15 , the arrow with the reference symbol N illustrates the desired value for the rotational speed of the pump units 21, 22. This desired value N is transmitted to both control devices 41, 42. Via the connection 43 or 44, which has its assigned pump unit 21 or 22, each control device 41, 42 receives the actual value for the current rotational speed of the electric motor, which respective electromagnetic rotary drive rotates at the current rotational speed. This rotational speed is determined in the bearingless electric motor, for example, by means of a Hall sensor.

[0130] The arrow on the pump units 21, 22 without a reference symbol symbolizes the fluid to be conveyed.

[0131] Via the communication connection 12, the two control devices 41, 42 can exchange control signals with one another and, in particular, also the respective actual values for the rotational speed of the electric machines. As an option (not shown in Figure 15 In addition, an additional signal connection can be provided via which the first control device 41 receives the actual value of the rotational speed of the electric machine of the second pump unit 22 directly, i.e. not via the second control device 42, and the second control device 42 receives the actual value of the rotational speed of the electric machine of the first pump unit 21 directly, i.e. not via the first control device 41.

[0132] In the flowchart in Figure 16 the previously described basic embodiment is illustrated. In step 10, each control device 41, 42 reads in a desired value for the rotational speed of the pump, i.e. a desired value for the rotational speed of the pumping device 1.

[0133] In step 11, the two control devices 41 and 42 communicate with one another via the communication connection 12 in order to determine whether the shaftless electric machine of the respective further pump unit 21 or 22 is operating without faults. For such a check, numerous error detection procedures are known to the person skilled in the art.

[0134] If it is determined in step 11 that the shaftless electric machines of both pump units 21, 22 are operating without faults, then in step 12 the actual value for the rotational speed of the electric machine for both pump units 21, 22 is set to be smaller than the desired value for the rotational speed of the pump by a factor (not shown in ).

[0135] If it is determined in step 11 that one of the two shaftless electric machines of the two pump units 21, 22 is not operating, then in step 13 the desired value for the rotational speed of the electric machine for the other shaftless electric machine is set to be the value for the rotational speed of the pump.

[0136] In step 14, it is then checked after step 12 or after step 13 whether the difference between the actual value for the rotational speed of the electric machine and the desired value is within a predefinable tolerance range.

[0137] In step 15, the two control devices 41 and 42 subsequently exchange the result of the check in step 14 via the communication connection 12.

[0138] The process then starts again at step 10.

[0139] In order to ensure a particularly high operating reliability, preferably all connections are designed redundantly, information is exchanged via the connections, i.e. for example the communication connection 12.

[0140] Figure 17 A symbolic illustration similar to Figure 15 shows a first variant of an embodiment of the method according to the application. In this first variant, the flow rate through the pumping device 1 is used as an operating parameter. For this purpose, a flow rate sensor 61 is provided, which is preferably arranged in the vicinity of the second outlet 222. As already described above, the flow rate sensor 61 is signal-connected to the first control unit 41 via a first signal connection 601 and to the second control unit 42 via a second signal connection 602. Thus, the flow rate sensor 61 can direct the actual value of the flow rate to both control devices 41, 42, which then compare this actual value with the desired value for the flow rate and, in the event of a discrepancy, adjust the actual value of the flow rate to the desired value. For this adjustment, a communication connection 12 between the two control devices 41, 42 is not absolutely necessary. If one of the control devices 41 or 42 or one of the pump units 21 or 22 fails, this will result in a change in the actual value of the flow rate, which is communicated to both control devices 41, 42 via the signal connections 601, 602. The control device 41 or 42 of the still functioning pump unit 21 or 22 will then change the rotational speed of the associated bearingless motor such that the actual value of the flow rate returns to the desired value of the flow rate.

[0141] Figure 18 A symbolic illustration similar to Figure 15 shows a second variant of an embodiment of the method according to the application. In this second variant, the flow rate through the pumping device 1 is also used as an operating parameter. In contrast to the first variant, in the second variant, the flow rate measurement for determining the actual value of the flow rate is redundantly designed. For example, as shown in Figure 18 , this can be achieved by providing a second flow rate sensor 63 in addition to the flow rate sensor 61. Each flow rate sensor 61, 63 is then signal-connected to each control device 41, 42. The flow rate sensor 61 is signal-connected to the first control device 41 or to the second control device 42 via the signal connections 601, 602, and the second flow rate sensor 63 is signal-connected to the first control device 41 or to the second control device 42 via the signal connections 603 and 604. As an alternative, it is of course also possible to provide only one flow rate sensor instead of two flow rate sensors 61, 63, which is redundantly designed in such a way, for example by the number of ultrasonic transducers, that it can make two independent measurements of the flow rate.

[0142] Figure 19 A symbolic illustration similar to Figure 15The symbolic illustration shows a third variant for an embodiment of the method according to the application. In this third variant, the pressure difference generated by the pumping device 1 is used as operating parameter. For this purpose, two pressure sensors 621 and 622 (see also Figure 10 ) are provided, wherein the first pressure sensor 621 is arranged such that with it the pressure of the fluid at the first inlet 211 can be determined and the second pressure sensor 622 is arranged such that with it the pressure at the second outlet 222 can be determined. Thus, by means of the two pressure sensors 621 and 622, the pressure difference generated by the pumping device 1 can be determined. Each of the two pressure sensors 621 and 622 is in each case signal-connected to both control devices 41 and 42. The pressure sensor 622 is signal-connected to the first control unit 41 or to the second control unit 42 via the connection 623 or 624. The pressure sensor 621 is signal-connected to the first control device 41 or to the second control device 42 via the connection 625 or 626.

[0143] Thus, in each case, the two pressure sensors 621 and 622 can transmit the actual value of the pressure at the first inlet 211 and the actual value of the pressure at the second outlet 222 to both control devices 41, 42. The control devices 41, 42 then determine the actual value of the pressure difference generated by the pumping device 1 and compare it with the desired value for the pressure difference. In the event of a deviation between the actual value for the pressure difference and the desired value for the pressure difference that exceeds a predefinable tolerance range, the actual value of the pressure difference is adjusted to the desired value. For this adjustment, the communication connection 12 between the two control devices 41, 42 is not absolutely necessary. If one of the control devices 41 or 42 or one of the pump units 21 or 22 fails, this leads to a change in the actual value for the pressure difference, which can be detected by both control devices 41, 42. The control device 41, 42 of the still functioning pump unit 21 or 22 or of the still functioning control device 41 or 42 then changes the rotational speed of the associated bearingless motor such that the actual value of the pressure difference returns to the desired value for the pressure difference.

[0144] Figure 20 The symbolic illustration shows a fourth variant for an embodiment of the method according to the application, which is similar to the third variant Figure 15 . In this fourth variant, two operating parameters are used, namely the pressure difference generated by the pumping device 1 and the flow through the pumping device 1. Thus, this fourth variant is a combination of the third variant Figure 19 and the second variant Figure 18 or of the third variant Figure 17combination of the pressure sensors 621 and 622, by which the pressure difference generated by the pumping device 1 can be determined, and the flow sensor 61, by which the flow through the pumping device 1 can be determined. In this case, it is possible to provide only one flow sensor 61, as explained in Figure 17 Figure 18

[0145] In particular with regard to the operating parameters pressure difference and flow, it is also possible to determine these operating parameters alternatively or additionally from other operating parameters of the pumping device 1.

[0146] For example, the flow through the pumping device 1 can be determined from the rotational speed of the bearingless motor and the generated torque. The torque of the bearingless motor is very precisely known from electrical values, since there is no friction as in the case of mechanical bearings, for example.

[0147] The torque for different rotational speeds can then be plotted as a function, which depends on the density of the fluid, its viscosity (dynamic viscosity) and the flow. Using a reference fluid, for example human or animal blood at a temperature of 37°C, a family of characteristic curves for different rotational speeds can then be recorded experimentally, which shows the dependence of the flow on the torque. As has been described, this family of characteristic curves can then be described by a family of functions in order to determine the coefficients for the parameters in the functional dependence in this way. These parameters or the functional dependence can then be stored in the control devices 41, 42, so that during operation the actual value of the flow can be determined from the actual value of the torque. As an alternative, it is of course also possible to store the entire family of characteristic curves, for example as a look-up table, in the two control units 41, 42.

[0148] Depending on which values are known from the "torque-flow" characteristic curve family, it is also possible to determine other values of the fluid. For example, in the "torque-flow" characteristic curve family, the torque at zero flow is proportional to the viscosity. This means, for example, that if the flow is determined by measurement, the viscosity of the fluid can be determined. In this way, for example, it is also possible to generate a "torque-flow" characteristic curve family in which the viscosity is a parameter, i.e. the different curves of the characteristic diagram belong to different viscosities.

[0149] ​​The pumping device 1 according to the invention or the method according to the invention is particularly suitable for applications in which highly sensitive substances, such as blood or biotechnological fluids containing cells, proteins, or other sensitive components, are delivered. Exemplary features are described herein in applications such as extracorporeal membrane oxygenation (ECMO) to support lung function, applications in heart-lung machines, biopharmaceutical manufacturing processes, such as filtration processes, in which desired substances (e.g., proteins) are removed as permeates from fluids produced in bioreactors, and perfusion processes in the biotechnology or biopharmaceutical industries.

[0150] In the preceding description, pumping device 1, having two pump units 21, 22, was explained. However, such embodiments of the pumping device according to the invention are also possible, in which two or more pump units, such as three or even more pump units, are connected in series one after another.

Claims

1. A pumping device for conveying fluid, the pumping device having a disposable device (2) designed for single use and a reusable device (3) designed for multiple uses, wherein, The disposable device (2) is designed to be inserted into the reusable device (3) and includes two pump units (21, 22) arranged in series, one after the other. Each pump unit (21, 22) includes a rotor (214, 224) for conveying fluid. Each rotor (214, 224) is designed as a bearingless motor rotor and is magnetically levitated and driven without contact for rotation about an axial direction (A). The reusable device (3) is designed to be inserted into the disposable device (2) and includes a stator (31, 32) for each rotor (214, 224). The stators (31, 32) and the rotors (214, 224) form an electromagnetic rotary actuator for rotating the rotors (214, 224) about the axial direction (A), wherein each stator (31, 32) is designed as a bearing and actuator stator through which the rotors (214, 224) can be magnetically driven without contact and magnetically levitated without contact relative to the stators (31, 32), and wherein each stator (31, 32) is provided with an independent control device (41, 42) designed for independent activation of the respective stator (31, 32).

2. The pumping device according to claim 1, wherein, The disposable device (2) has two cup-shaped protrusions (217, 227), in each of the cup-shaped protrusions (217, 227) a rotor (214, 224) is disposed therein, and wherein the reusable device (3) has two grooves (33, 34), each of the grooves (33, 34) being designed to receive one of the cup-shaped protrusions (217, 227).

3. The pumping device according to claim 2, wherein, The reusable device (3) is designed such that, in the operating state, the rotors (214, 224) of the disposable device (2) each rotate about a rotation axis (A1, A2), the rotation axis (A1, A2) forming an angle with the vertical line that is different from zero degrees, the angle being less than 90°.

4. The pumping device according to any one of claims 1 to 3, wherein, The first pump unit (21) has a first inlet (211) and a first outlet (212) for fluid, wherein the second pump unit (22) has a second inlet (221) and a second outlet (222) for fluid, wherein each inlet (211, 221) is designed such that fluid flows from the axial direction (A) to the corresponding rotor (214, 224), and wherein each outlet (212, 222) is designed such that fluid exits the corresponding pump unit (21, 22) in a discharge direction (D) perpendicular to the axial direction (A).

5. The pumping device according to claim 4, which is designed such that the fluid is deflected at least 90° between the first outlet (212) and the second inlet (221).

6. The pumping device according to claim 4, which is designed such that the fluid is deflected a total of 270° between the first outlet (212) and the second inlet (221).

7. The pumping apparatus according to any one of claims 1 to 3, wherein, In each case, a separate power supply (51, 52) is provided for each stator (31, 32) so that if one of the power supplies (51, 52) fails, power can still be supplied to one of the stators (31, 32).

8. The pumping apparatus according to any one of claims 1 to 3, wherein, An advanced control unit (40) is provided, whose signals are connected to all control devices (41, 42) for the stator (31, 32).

9. The pumping apparatus according to any one of claims 1 to 3, wherein, An emergency energy storage device (512, 522) is provided so that if the main energy source (511, 521) used to power the stators (31, 32) can no longer supply energy to one or all pump units (21, 22), energy can be supplied from the emergency energy storage device (512, 522) to each stator (31, 32).

10. The pumping apparatus according to any one of claims 1 to 3, wherein, The single-use device (2) and / or the reusable device (3) include identification elements (81, 82), through which the single-use device (2) and the reusable device (3) can exchange information with each other.

11. A single-use device designed for single use and for use in a pumping device (1) designed according to any one of claims 1 to 10.

12. A method for operating a pumping device, said pumping device being designed according to any one of claims 1 to 10, wherein, The expected value of the operating parameter for the pumping device (1) is predetermined for each control device (41, 42), wherein the actual value for this operating parameter is determined by means of sensors (6, 61, 63, 621, 622), and wherein the actual value is transmitted to each control device (41, 42).

13. The method according to claim 12, wherein, The control devices (41, 42) exchange signals with each other, by means of which each control device (41, 42) can check the function of another pump unit (21, 22) that is different from its own pump unit.

14. The method according to any one of claims 12 to 13, wherein, The operating parameters are: the flow rate through the pumping device (1) or the pressure difference generated by the pumping device (1).

15. The method according to any one of claims 12 to 13, wherein, The flow rate of the pumping device (1) is determined from the rotational speed and torque, and the rotors (214, 224) are driven by the rotational speed and the torque.

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