Device for replacing pump unit of centrifugal pump and centrifugal pump

Abstract

The invention relates to a device for replacing a pump unit of a centrifugal pump, comprising a pump unit and a stator which extends in the axial direction from a first axial end, at which a cup-shaped recess is provided, into which the pump unit can be inserted, to a second axial end, the cup-shaped part can be inserted into a cup-shaped recess of the stator, a rotor for conveying a fluid is arranged in the pump housing, the rotor is provided with a magnetically effective core, the rotor can rotate around the axial direction, and the stator is designed for non-contact magnetic driving and non-contact magnetic suspension of the rotor. Wherein the rotor is passively geomagnetically stable relative to the stator at least in the axial direction. The device comprises an actuating device with which a mechanical force can be exerted on the pump unit, the mechanical force acting in the axial direction and being oriented such that the mechanical force separates the pump unit from the stator in the axial direction. The invention further relates to a centrifugal pump for conveying a fluid, comprising such a device.

Description

Technical Field

[0001] The invention relates to a device for replacing a pump unit of a centrifugal pump according to the preamble of the independent patent claim. The invention further relates to a centrifugal pump having such a device. Background Art

[0002] Centrifugal pumps are known which consist of a pump unit and a stator, wherein a rotor is arranged in the pump unit and forms the impeller of the centrifugal pump. The pump unit can be inserted into the stator and together with the stator forms an electromagnetic rotary drive. In the pump unit, the rotor can be magnetically supported in a contactless manner by means of the stator and can be driven in a contactless manner to rotate about an axial direction. Such centrifugal pumps are known, for example, by the applicant under the product name BPS pumps are available on the market.

[0003] In these centrifugal pumps, a cup-shaped recess is provided in one of the axial ends of the stator, into which a pump unit can be inserted, wherein the pump unit comprises a pump housing having a cup which can be inserted into the cup-shaped recess of the stator.

[0004] The stator and the rotor form an electromagnetic rotary drive, which is designed according to the principle of a bearingless motor. The term bearingless motor refers to an electromagnetic rotary drive in which the rotor can be fully magnetically supported relative 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 a stator of the electric drive and a stator of the magnetic bearing. The electric winding of the stator can be used to generate a magnetic rotating field, which exerts a torque on the rotor on the one hand, which realizes the rotation of the rotor around the desired rotation axis defined by the axial direction, and the magnetic rotating field exerts an arbitrarily adjustable lateral force on the rotor on the other hand, so that the radial position of the rotor can be actively controlled or adjusted. Therefore, the three degrees of freedom of the rotor, namely its rotation and its radial position (two degrees of freedom), can be actively adjusted. With regard to the other three degrees of freedom, namely its position in the axial direction and the tilt relative to the radial plane perpendicular to the desired rotation axis (two degrees of freedom), the rotor is passively magnetically supported or stabilized by magnetic resistance, that is, it cannot be controlled. The lack of a separate magnetic bearing with a complete magnetic bearing is the property of the rotor which gives the bearingless motor its name. In a bearing and drive stator, the bearing function cannot be separated from the drive function.

[0005] A particular advantage of such a centrifugal pump is that the rotor is designed as a one-piece rotor, which is both the rotor of the electromagnetic rotary drive and thus the rotor of the electromagnetic drive and the magnetic bearing, and also the rotor of the pump for conveying the fluid. This results in the advantage of a very compact and space-saving design.

[0006] Centrifugal pumps with contactless magnetically supported and magnetically driven rotors, such as those designed according to the principle of bearingless motors, have proven themselves in a large number of applications. Due to the lack of mechanical bearings, such centrifugal pumps are suitable for applications in which very sensitive substances are conveyed, such as blood pumps, or for applications with very high demands on purity, such as in the semiconductor industry, the pharmaceutical industry, the biotechnology industry, or for applications in which abrasive or aggressive substances are conveyed which would very quickly destroy mechanical bearings, such as pumps for slurries, sulfuric acid, phosphoric acid or other chemicals in the semiconductor industry.

[0007] In the biotechnology industry or in the pharmaceutical industry, such centrifugal pumps are for example used in combination with bioreactors, for example, for fluid transport to or from bioreactors. Particularly in such applications, for example, in the process of carrying out biological activities therein, sterility is very important. It is very often a time-consuming and cost-intensive factor to sterilize the device (for example, by means of steam sterilization). For this reason, nowadays, the components of the corresponding device are more and more tended to be designed as single-use parts for such biotechnology processes, in order to avoid time-consuming sterilization processes or to reduce them to a minimum. In particular, those components that are in direct contact with biological substances during the process are usually designed as single-use parts. The term single-use component specifies a component or component that can only be used once according to its intended purpose. After use, the single-use component is disposed of and replaced by a new (that is, unused) single-use component for the next application.

[0008] Therefore, centrifugal pumps are known in which the pump unit is designed as a single-use component. After the respective application, the pump unit is separated from the stator and replaced by a new, unused pump unit. With regard to the highest possible efficiency, it is desirable that the pump unit can be replaced in a very simple and quick manner and with the least possible effort.

[0009] For this purpose, it is known to lock the pump unit in the cup-shaped recess of the stator, for example by means of a bayonet lock. In order to replace the pump unit, the bayonet lock is then opened, the pump unit is replaced with a new pump unit, and the bayonet lock is locked again.

[0010] Although this design has proven to be very successful in practice, there is a need for improvement, especially for such centrifugal pumps designed for very high powers, for example centrifugal pumps with an electric rotary drive designed for powers greater than 4 kW. Such centrifugal pumps usually include very strong permanent magnets arranged in the rotor and / or stator. In particular, in such designs, huge magnetic forces act between the rotor and the stator. Even when the windings of the stator are no longer applied with current, passive magnetic forces (i.e., for example magnetic resistance) continue to act. If the pump unit is then to be replaced, these huge magnetic forces between the rotor and the stator must be overcome. Here, there is a very significant risk that the operating personnel will be injured or the components of the centrifugal pump will be damaged when replacing the pump unit. The magnetic forces are usually so great that it is almost impossible to separate the pump unit from the stator by hand, or only with great effort. Summary of the invention

[0011] Starting from this prior art, the object of the present invention is therefore to propose a device for replacing the pump unit of a centrifugal pump with a contactless magnetic drive and a magnetically suspended rotor, which device makes it possible to separate the pump unit from the stator very simply, quickly and safely. In addition, the object of the present invention is to propose a centrifugal pump with such a device for replacing the pump unit.

[0012] The subject matter of the invention which meets this object is characterized by the features of the independent patent claims.

[0013] Therefore, according to the invention, a device for replacing a pump unit of a centrifugal pump is proposed, the centrifugal pump comprising a pump unit and a stator extending in the axial direction from a first axial end to a second axial end, wherein a cup-shaped recess is provided at the first axial end, into which the pump unit can be inserted, wherein the pump unit comprises a pump housing with a cup-shaped portion, which can be inserted into the cup-shaped recess of the stator, wherein a rotor for conveying a fluid is arranged in the pump housing, the rotor having a magnetically effective core, wherein the rotor can rotate about the axial direction, and wherein the stator is designed for contactless magnetic drive and contactless magnetic suspension of the rotor, wherein the stator is passively magnetically stabilized relative to the stator at least in the axial direction. The device comprises an actuating device with which a mechanical force can be exerted on the pump unit, wherein the mechanical force acts in the axial direction and is oriented in such a way that it separates the pump unit from the stator in the axial direction.

[0014] By means of such a device, with which a mechanical force can be exerted on the pump unit in the axial direction, the pump unit can be separated from the stator by the operator in a particularly simple manner and with very little manual effort. This results in a significantly reduced risk of injury to the operator and the pump unit is also reliably protected from damage. In addition, the device enables a particularly rapid replacement of the pump unit, which is a great advantage, in particular but not only for applications such as in biotechnology, in which the pump unit is designed as a single-use component. This is because, in particular in such embodiments in which the pump unit is designed as a single-use component, it is a substantial aspect that the pump unit can be replaced or exchanged in as little time as possible.

[0015] However, even in applications where the pump unit is designed for multiple use or for repeated use, the simple and rapid detachability of the pump unit from the stator is an advantage, for example if the pump unit or a component of the pump unit needs to be serviced, repaired or replaced. For example, it may be necessary to replace a rotor forming a wheel or impeller of a centrifugal pump.

[0016] Preferably, the device is fixable to or relative to the stator.

[0017] Embodiments are possible in which the device for replacing the pump unit is permanently attached to the stator, i.e. not only when the pump unit is to be replaced. In other embodiments, the device is only fixed to the stator for the replacement process. After the pump unit has been replaced, the device is removed and separated from the stator. Embodiments are also possible in which the device can be fixed relative to the stator, for example by fixing the device and the stator on a common rail or the like.

[0018] According to a preferred embodiment, the actuating device is designed so that a mechanical force acts on a cup-shaped recess in the stator or on a cup-shaped portion of the pump housing. The actuating device then presses against the bottom of the cup-shaped portion or against the bottom of the cup-shaped recess so that the pump unit alone or the pump unit together with the cup-shaped recess is pressed out of the stator in the axial direction.

[0019] In a preferred embodiment, the actuating device comprises a piston displaceable in the axial direction, wherein the piston is insertable into a centrally arranged opening in the stator, and the displacement of the piston relative to the stator generates a mechanical force that separates the pump unit from the stator in the axial direction. The centrally arranged opening preferably extends in the axial direction from the second axial end of the stator to the cup-shaped recess or the cup-shaped portion of the pump unit. The piston is arranged in the centrally arranged opening, which piston is displaceable in the axial direction relative to the stator. By displacing the piston, the pump unit is then pressed out of the stator alone or together with the cup-shaped recess in the axial direction. If the piston acts directly on the cup-shaped portion of the pump unit, the cup-shaped recess is provided with an opening through which the piston can pass.

[0020] The displacement of the piston in the axial direction can be performed, for example, by means of a manually operated threaded crank or by means of a motor, for example by means of a spindle motor.

[0021] A preferred measure is that the device comprises a guide rail that can be fixed to the stator, wherein a support element that can be displaced in the axial direction is arranged on the guide rail, which support element protects the pump unit from tilting when the pump unit is separated from the stator. The guide rail with the support element protects the pump unit from tilting relative to the axial direction both when the pump unit is inserted into the stator and when the pump unit is separated from the stator, and ensures that the pump unit cannot become twisted in the stator.

[0022] According to a further preferred embodiment, the actuating device is designed so that the mechanical force acts on a region of the pump housing arranged outside the cup-shaped recess of the stator. Thus, when the pump unit is inserted into the stator, the force acting on the pump unit is applied here to a region of the pump unit that is not arranged in the cup-shaped recess of the stator.

[0023] Of course, embodiments are also possible in which the forces acting on the pump unit are applied both to the area of ​​the pump unit which is arranged in the cup-shaped recess of the stator and to the area which is not arranged in the cup-shaped recess of the stator.

[0024] A further preferred measure is that the actuating device comprises a spring element which can be inserted into a centrally arranged opening in the stator, wherein the spring element is designed such that when the pump unit is inserted into the cup-shaped recess, the spring element is tensioned in the axial direction. As long as the pump unit is fixed in the stator, the spring element is under tension. If the pump unit is now to be separated from the stator, this tension on the spring element serves to support or cause the separation of the pump unit from the stator.

[0025] Therefore, the spring element is designed and arranged in such a way that the spring element is tensioned when the pump unit is inserted, i.e. the pump unit is inserted into the stator against the force of the spring element. When the pump unit is inserted, the spring element has a damping effect, which has the advantage that strong magnetic forces trying to pull the pump unit into the stator can be counteracted. In this way, the pump unit can be inserted gently and carefully into the stator. In particular, it can be reliably avoided that the pump unit hits the stator during insertion. When the pump unit is separated from the stator, the tensioned spring element exerts a force on the pump unit that acts in the axial direction, which force supports or causes the separation from the stator.

[0026] According to a preferred embodiment, the device comprises a mounting device which can be fixed to a first axial end of the stator, wherein the mounting device has an annular base which is designed to surround the pump housing, wherein several guide elements are arranged on the base in order to guide the pump housing in the axial direction into the cup-shaped recess of the stator, wherein several attachment elements are provided for fixing the pump housing, and wherein the mounting device comprises several elastic elements which are tensioned in the axial direction when the pump unit is fixed in the stator.

[0027] When the pump unit is inserted into the stator, the elastic element (e.g., spring) is tensioned, i.e., the pump unit is inserted into the stator against the spring force of the elastic element. When the pump unit is separated from the stator, the elastic element causes a mechanical force that acts in the axial direction and tries to push the pump unit out of the stator.

[0028] In a further preferred embodiment, the device comprises a mounting ring, which can be fixed to a first axial end of the stator, such that the mounting ring is arranged around the cup-shaped recess, wherein a first guide rod and a second guide rod are arranged on the mounting ring, each of which extends in the axial direction, wherein a pivotable holding device for holding the pump unit is provided at the first guide rod, the holding device being pivotable into a holding position in which the holding device rests against the second guide rod, and wherein at least one tensioning lever is provided, by actuation of which the holding device can be displaced in the axial direction along the guide rod. In this embodiment, a mechanical force is generated by means of the at least one tensioning lever, which can displace the pump unit in the axial direction along the guide rod.

[0029] It is preferred here that a locking element is provided at one of the guide rods, with which the retaining device can be fixed to the guide rod when the pump housing is arranged in the cup-shaped recess. In doing so, an unintentional separation of the pump unit from the stator is avoided.

[0030] In a further preferred embodiment, the device comprises a bayonet ring which is fixable to the first axial end of the stator such that the bayonet ring is arranged around the cup-shaped recess, wherein the bayonet ring is designed for bayonet connection to a pump housing of the pump unit.

[0031] Preferably, the bayonet ring is designed in such a way that the pump housing can be fixed in the bayonet ring by a rotational movement relative to the bayonet ring about the axial direction, subsequently a movement in the axial direction and subsequently a rotational movement about the axial direction.

[0032] Preferably, a fixing pin is provided at the bayonet ring, with which the pump unit can be fixed in the bayonet ring when the pump housing is arranged in the cup-shaped recess. In doing so, an unintentional separation of the pump unit from the stator is avoided.

[0033] Furthermore, the invention proposes a centrifugal pump for conveying a fluid, comprising a pump unit and a stator extending in an axial direction from a first axial end to a second axial end, wherein a cup-shaped recess is provided at the first axial end, into which the pump unit can be inserted, wherein the pump unit comprises a pump housing with a cup-shaped portion, which can be inserted into the cup-shaped recess of the stator, wherein a rotor for conveying the fluid is arranged in the pump housing, the rotor having a magnetically effective core, wherein the rotor together with the stator forms an electromagnetic rotary drive, wherein the stator is designed for contactless magnetic drive and contactless magnetic suspension of the rotor, and wherein the rotor is passively magnetically stabilized at least in the axial direction. A device designed according to the invention for replacing the pump unit is provided.

[0034] According to a preferred embodiment, the device for replacing the pump unit is designed such that it can in each case be removed from the centrifugal pump after the pump unit has been replaced.

[0035] Of course, embodiments are also possible in which the device for replacing the pump unit is always fixed to the centrifugal pump, ie not only when replacing the pump unit.

[0036] In a particularly preferred embodiment of the centrifugal pump, the electromagnetic rotary drive is designed as a temple motor, wherein the stator has a plurality of coil cores, each of the plurality of coil cores comprising a longitudinal leg and a transverse leg, the longitudinal leg extending in an axial direction from a first end to a second end, the transverse leg being arranged at the second end of the longitudinal leg and extending in a radial direction perpendicular to the axial direction, wherein the coil core is arranged around the rotor with respect to the circumferential direction such that the rotor is arranged between the transverse legs of the coil core, and wherein at least one concentrated winding is provided on each longitudinal leg, which winding surrounds the corresponding longitudinal leg.

[0037] Further advantageous measures and embodiments of the invention are evident from the dependent claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] In the following the invention will be explained in more detail with reference to embodiments and with reference to the accompanying drawings, in which are shown (partially in section):

[0039] Figure 1a : Perspective view of a centrifugal pump, partially in section,

[0040] Figure 1b :like Figure 1a , but for the centrifugal pump variant,

[0041] Figure 2 : From Figure 1a or Figure 1b Cross-sectional view of a pump unit of a centrifugal pump,

[0042] Figure 3 : A perspective exploded view, partly in section, of a first embodiment of a device for replacing a pump unit of a centrifugal pump,

[0043] Figure 4 : A perspective view of a first embodiment fixed to a centrifugal pump,

[0044] Figure 5 :like Figure 4 , but when replacing the pump unit,

[0045] Figure 6 : A perspective exploded view, partly in section, of a second embodiment of a device for replacing a pump unit of a centrifugal pump,

[0046] Figure 7 : A perspective view of a second embodiment fixed to a centrifugal pump,

[0047] Figure 8 : A perspective view of a third embodiment of a device for replacing a pump unit of a centrifugal pump, the pump unit being separated from the stator,

[0048] Fig. 9 :like Figure 8 , but after the first stage of inserting the pump unit into the stator,

[0049] Fig.10 :like Fig. 9 , but after the pump unit has been inserted into the stator,

[0050] Fig.11 : A perspective exploded view of a variant of the third embodiment,

[0051] Fig.12 : From Fig.11 A perspective view of a variant of

[0052] Fig.13 : A perspective view of a fourth embodiment of a device for replacing a pump unit of a centrifugal pump, and

[0053] Figure 14-17 : Perspective views of a fourth embodiment in various stages of insertion of a pump unit in each case. DETAILED DESCRIPTION

[0054] The present invention proposes a device for replacing a pump unit of a centrifugal pump. Figure 1a , Figure 1b and Figure 2 An embodiment of a centrifugal pump is explained, to which the device according to the invention is suitable.

[0055] Figure 1aAn embodiment of a centrifugal pump known per se is shown in a perspective view (partially in section) and is denoted in its entirety by reference numeral 200. Figure 1a In the expression of Figure 1b A variant of a centrifugal pump 200 is shown. The centrifugal pump 200 comprises a pump unit 50 and a stator 100, which extends in the axial direction A from a first axial end 101 to a second axial end 102. The stator 100 further comprises a stator housing 120, which is preferably designed as a hermetically sealed stator housing 120 and surrounds the other components of the stator 100 in a hermetically sealed manner. A cup-shaped recess 121 is provided at the first axial end 101 of the stator 100, into which the pump unit 50 can be inserted.

[0056] Figure 2 Shown from Figure 1a or Figure 1b A cross-sectional view of a pump unit 50 of a centrifugal pump 200 is shown. A rotor 51 is arranged in the pump unit 50, which forms a wheel or impeller with which a fluid is conveyed. When the pump unit 50 is inserted into the cup-shaped recess 121 of the stator 100, the stator 100 and the rotor 51 form an electromagnetic rotary drive for rotating the rotor 51 about an axial direction A. The stator 100 is designed for contactless magnetic suspension of the rotor 51, preferably according to the principle of a bearingless motor. For this purpose, the stator 100 is designed as a bearing and drive stator, with which the rotor 51 can be contactlessly magnetically driven for rotation about the axial direction A and can be contactlessly magnetically suspended relative to the stator 100, wherein the rotor 51 is passively magnetically stabilized relative to the axial direction A and is oriented in a radial plane perpendicular to the axial direction A (which is determined by the radial plane). Figure 1a and Figure 1b Line E in the figure indicates active magnetic levitation.

[0057] The term bearingless motor refers to an electromagnetic rotary drive in which the rotor 51 can be completely magnetically suspended relative to the stator 100, wherein no separate magnetic bearing is provided. For this purpose, the stator 100 is designed as a bearing and drive stator, which is both an electrically driven stator 100 and a magnetically suspended stator 100. The electric windings of the stator 100 can be used to generate a magnetic rotating field, which on the one hand exerts a torque on the rotor 51, which realizes the rotation of the rotor 51 around the desired rotation axis defined by the axial direction A, and on the other hand exerts an arbitrarily adjustable lateral force on the rotor 51, so that the radial position of the rotor 51 in the radial plane E can be actively controlled or adjusted. Therefore, three degrees of freedom of the rotor 51 can be actively adjusted, namely its rotation and its radial position (two degrees of freedom). With regard to the other three degrees of freedom, namely its position in the axial direction A and its tilt relative to the radial plane E perpendicular to the desired rotation axis (two degrees of freedom), the rotor 51 is passively magnetically suspended or stabilized by magnetic resistance, that is, it cannot be controlled. The lack of separate magnetic bearings with full magnetic suspension of the rotor 51 is the property that gives the bearingless motor its name. In the bearing and drive stator 100, the bearing function cannot be separated from the drive function.

[0058] Preferably, the electromagnetic rotary drive with the stator 100 and the rotor 51 is designed as a so-called temple motor. The stator 100 comprises a plurality of coil cores 125, here eight coil cores 125, each of which comprises a longitudinal leg 126 and a transverse leg 127, the longitudinal leg 126 extending in the axial direction A from the first end (at Figure 1a and Figure 1b The transverse legs 127 are arranged at the second ends of the longitudinal legs 126 and in the radial plane E. Each transverse leg 127 extends from the associated longitudinal leg 126 in the radial direction toward the rotor 51 or the cup-shaped recess 121 and is limited by a radial inner end face. The coil core 126 is arranged around the cup-shaped recess 121 with respect to the circumferential direction so that the rotor 51 is arranged between the radial inner end faces of the transverse legs 127 of the coil core 126.

[0059] All first ends of the longitudinal legs 126 are connected to each other via a back iron 122 for conducting magnetic flux. At each longitudinal leg 126, at least one concentrated winding 160, 161 is arranged, which surrounds the corresponding longitudinal leg 126. With regard to the number and arrangement of the concentrated windings 160, 161, many variants are known, which are not explained in more detail here. For example, there are such windings 160, which are wound around exactly one longitudinal leg 126, and such windings 161, which are arranged around exactly two longitudinal legs 126.

[0060] The plurality of longitudinal legs 126 extending in the axial direction A and reminiscent of the columns of a temple give the temple-shaped motor its name.

[0061] exist Figure 1b In the variant represented in , the stator 100 has a centrally arranged opening 103, which extends in the axial direction A from the second axial end 102 of the stator 100 into the cup-shaped recess 121. The centrally arranged opening 103 is designed in a cylindrical manner and penetrates the bottom of the cup-shaped recess 121. Therefore, the centrally arranged recess 121 extends in the axial direction A from the first axial end 101 through the entire stator 100 to the second axial end 102. With respect to the radial direction, the centrally arranged opening 103 is delimited by an inner wall 104. Preferably, the inner wall 104 is designed as a gas-tight sealing wall 104, so that components arranged in the stator 100, such as the coil core 125 on which the concentrated windings 160, 161 are arranged, are gas-tightly sealed.

[0062] exist Figure 1a In the embodiment represented in , there is no centrally arranged opening 103 .

[0063] The pump unit 50 includes a pump housing 52 having an inlet 523 and an outlet 524 for a fluid, and a rotor 51 for conveying the fluid arranged in the pump housing 52, which can rotate around an axial direction A. The rotor 51 includes a magnetically effective core 511, which interacts magnetically with the stator 100 to form a torque and generate a magnetic levitation force. For example, the magnetically effective core 511 is a permanent magnet ring or a permanent magnetic disk.

[0064] The pump housing 52 is preferably made of a synthetic material (eg, polypropylene (PP), polyethylene (PE), polytetrafluoroethylene (PTFE) or a perfluoroalkoxy polymer). Of course, an embodiment in which the pump housing 52 is made of a metallic material (eg, stainless steel) is also possible.

[0065] In particular, the pump unit 50 may also be designed for a single use, i.e., as a single-use component. The term "single-use component" and other combinations of the component "single use" (such as single-use member, single-use device, etc.) refer to those devices, members or components designed for a single use, i.e., they can only be used once as expected, and then disposed of. For new applications, new, previously unused single-use components must then be used. When the pump unit 50 is constructed or designed as a single-use device, it is a substantial aspect that the pump unit can be easily assembled with or separated from the reusable stator 100 as much as possible. Therefore, the pump unit 50 should be able to be replaced very easily without requiring large assembly efforts.

[0066] Embodiments are also possible in which the magnetically active core 511 is designed in a non-permanent-magnetic manner, i.e. without permanent magnets. The rotor 51 is then designed, for example, as a reluctance rotor. The magnetically active core 511 of the rotor 51 is then made, for example, of a soft magnetic material. Suitable soft magnetic materials for the magnetically active core 511 are, for example, ferromagnetic or ferrimagnetic materials, i.e. in particular iron, nickel-iron, cobalt-iron, silicon-iron, μ-metal.

[0067] In addition, embodiments are possible in which the magnetically active core 511 of the rotor 51 comprises both ferromagnetic material and permanent magnetic material. For example, permanent magnets may be placed or inserted into a ferromagnetic matrix. Such embodiments are advantageous, for example, if one wishes to reduce the cost of a large rotor by saving permanent magnetic material.

[0068] Typically, the magnetically active core 511 is completely encapsulated in a plastic material. In other embodiments, the magnetically active core 511 is completely surrounded by a sheath composed of a ceramic material or a metallic material (eg, stainless steel or titanium or tantalum).

[0069] Furthermore, the rotor 51 comprises a plurality of guide vanes 513 for conveying the fluid from the inlet 523 to the outlet 524. The guide vanes 513 are arranged on a plastic sheath or on a sheath of the magnetically active core 511. The guide vanes 513 are preferably made of a plastic material and can, for example, be designed as a single piece with the plastic sheath. Of course, it is also possible to manufacture individual guide vanes 513 or all guide vanes 513 in a separate manufacturing process and then connect them to the plastic sheath of the magnetically active core 511, for example, by means of a welding process.

[0070] The impeller formed by the rotor 51 with the guide vanes 513 is preferably designed as a radial impeller, to which the fluid approaches from the inlet 523 in the axial direction A and which then deflects the fluid in the radial direction.

[0071] The pump housing 52 includes a bottom part 521 and a cover 522 for closing the bottom part 521. The bottom part 521 of the pump housing 52 has a cup 531 for receiving the rotor 51. The cup 531 is inserted into the cup-shaped recess 121 in the stator 100 so that the rotor 51 (more precisely, the magnetically effective core 511 of the rotor 51) is arranged between the transverse legs 127 of the coil core 125.

[0072] For example, the pump unit 50 is attached to the stator housing 120 by means of a plurality of screws 111. In other embodiments, the pump unit 50 is fixed to the stator 100 by means of a bayonet connection. In particular in embodiments of the pump unit 50 as a single-use component, the bayonet connection enables a quick replacement of the pump unit 50. Typically, the bayonet connection is secured by a pin lock.

[0073] In particular, if the centrifugal pump 200 is designed for very high outputs, for example for outputs of 4 kW or more, very large or very strong magnets, for example permanent magnets, are used in the rotor 51 and / or in the stator 100. This results in huge magnetic forces, making it very difficult to replace the pump unit 50. When replacing the pump unit 50, there is a significant risk of injury to the operator or damage to the pump unit 50 or the stator 100.

[0074] If the rotor 51 is passively magnetically suspended in the axial direction A, passive magnetic forces typically also act when the stator 100 is currentless, ie when no current is applied to the windings 160 , 161 of the stator 100 . In order to replace the pump unit 50 , these passive magnetic forces acting between the rotor 51 and the stator 100 must be overcome.

[0075] According to the invention, therefore, a device is proposed for replacing a pump unit 50 of a centrifugal pump 200. The device is designated in its entirety by the reference numeral 1.

[0076] Figure 3 A perspective exploded view of a first exemplary embodiment of a device 1 for replacing a pump unit 50 of a centrifugal pump 200 is shown. Figure 3 The representation in FIG. is partially in cross-section. Figure 4 A perspective view of a first embodiment of the device 1 is shown, wherein the device 1 is fixed to a centrifugal pump 200. Figure 4 In the settings, Figure 5 The device 1 is shown when the pump unit 50 is replaced.

[0077] The device 1 comprises an actuating device 6 with which a mechanical force can be exerted on the pump unit 50. The mechanical force acts in the axial direction A and is directed such that it separates the pump unit 50 from the stator 100 in the axial direction.

[0078] In a first embodiment, the actuating device 6 comprises a piston 61, which is preferably designed in a cylindrical manner, a fixed plate 62 and a crank 64, which is designed as a threaded crank with a threaded rod 641. The piston 61 is connected to the threaded rod 641 in a torque-proof manner. For example, the piston 61 and the threaded rod 641 can also be designed as a single piece. The fixed plate 62 is provided with an internal thread, which is designed to interact with the threaded rod 641. The piston 61 is arranged on one side of the fixed plate 62, and the threaded rod 641 protrudes on the other side of the fixed plate 62, so that the threaded rod 641 displaces the piston 61 linearly relative to the fixed plate 62 by turning the crank 64.

[0079] As in particular Figure 3As can be appreciated in the drawings, the stator 100 has a centrally arranged opening 103, which extends from the second axial end 102 of the stator 100 into the cup-shaped recess 121 in the axial direction A. The centrally arranged opening 103 is designed in a cylindrical manner and is dimensioned such that the piston 61 can be inserted into the centrally arranged opening 103 and can be moved back and forth in the opening 103 in the axial direction A.

[0080] The piston 61 is inserted into the centrally arranged opening 103 from the second axial end 102 of the stator 200. Subsequently, the fixing plate 62 is attached to the second axial end 102 of the stator by means of a plurality of screws 65, so that the fixing plate 62 is fixed to the stator 100. By actuating the crank 64, the piston 61 can now be moved back and forth in the centrally arranged opening 103 in the axial direction A.

[0081] By displacing the piston 61 in the direction of the first axial end 101 of the stator 100, a mechanical force can now be generated which pushes the pump unit 50 out of the stator 100 (see Figure 5 ).

[0082] exist Figure 4 and Figure 5 In the centrifugal pump 200 shown in FIG. 1 , the stator 100 comprises a receiving pot 105, in which a cup-shaped recess 121 is arranged, into which the pump unit 50 can be inserted. The receiving pot 105 forms a first axial end 101 of the stator 100. The receiving pot 105 is securely connected to the stator housing 120, for example by means of a form-locking connection and / or by means of an elastic seal. Of course, the receiving pot 105 can also be attached to the stator housing 120 by means of screws.

[0083] The pump unit 50 comprises an attachment ring 55 which extends around the cup 531 of the pump housing 52 and is firmly connected to the pump housing 52. The attachment ring 55 is used to attach the pump unit 50 to the stator 100, for example by means of screws 551.

[0084] exist Figure 4 and Figure 5 In the embodiment represented in , the pump unit 50 is pushed out of the stator 100 in the axial direction A in order to replace the pump unit 50 , ie a mechanical force is exerted on the cup 531 so that the cup and thus the entire pump unit 50 are pushed out of the stator 100 .

[0085] Figure 4 The centrifugal pump 200 is shown in a ready-to-operate state in which the pump unit 50 is arranged in the cup-shaped recess 121 of the stator 100. Figure 41 , the threaded rod 641 protrudes from the second axial end 102 of the stator 100. If the pump unit 50 is now to be separated from the stator 100, for example because the pump unit 50 is to be replaced by a new pump unit 50, the crank 64 is actuated so that the piston 61 in the centrally arranged opening 103 is displaced in the direction of the first axial end 101 of the stator 100. Since the centrally arranged opening 103 extends into the cup-shaped recess 121, a channel is provided in the bottom of the cup-shaped recess 121 so that the piston 61 can move through the bottom of the cup-shaped recess 121 and then press directly against the cup 531 of the pump housing 52 of the pump unit 50. Once the piston 61 rests against the cup 531 of the pump housing 52, the pump unit 50 is pushed out of the stator 100 when the crank 64 is further actuated. Figure 5 The centrifugal pump 200 is shown in an end position in which the pump unit 50 is completely pushed out of the stator 100. In this position, the pump unit 50 can be removed or replaced very easily, since only very weak magnetic forces (if any) still act between the rotor 51 and the stator 100. Figure 5 , it can also be appreciated that the threaded rod 641 has now been moved significantly further into the stator 100 .

[0086] Optionally, the device 1 for replacing the pump unit 50 includes a guide rail 66, which can be fixedly fixed to the stator 100 or fixedly fixed to the stator 100, and the guide rail 66 extends away from the stator 100 in the axial direction A from the first end 101 of the stator 100. A support element 67 is arranged on the guide rail 66, and the support element 67 is supported on the guide rail 66 and can move back and forth on the guide rail 66 in the axial direction A. The support element 67 is designed in such a way that the support element 67 supports the pump unit 50 when the pump unit 50 is pushed out of the stator 100. For example, the support element 67 can partially surround the pump unit 50 so that the pump unit 50 is just pushed out of the stator 100 in the axial direction A. In doing so, the pump unit 50 can be effectively prevented from being deformed or tilted due to a strong magnetic force, especially when the pump unit 50 is pushed out of the stator 100.

[0087] Of course, embodiments are also possible in which the movement of the piston 61 in the centrally arranged opening 103 is performed by a motor. For this purpose, a spindle motor can be provided instead of the crank 64, for example, which moves the piston 61 in the centrally arranged opening 103.

[0088] The device 1 may be permanently mounted on the centrifugal pump 200 or on the stator 100 , for example also during operation of the centrifugal pump 200 .

[0089] Alternatively, it is also possible that the device 1 is only fixed to the stator 100 when needed (i.e. to replace the pump unit 50) and is removed from the stator 100 again after the pump unit 50 has been replaced. Furthermore, it is possible that some components of the device 1 are permanently fixed to the stator 100, while other components of the device 1 are only fixed to the stator 100 for replacing the pump unit.

[0090] Figure 6 A perspective exploded view of a second embodiment of a device 1 for replacing a pump unit 50 according to the invention is shown, wherein the representation is partially in section. For a better understanding, Figure 7 Also shown is a perspective view of a second embodiment secured to a centrifugal pump 200 .

[0091] In the following, only the differences from the first embodiment will be discussed. Identical parts or functionally equivalent parts of the second embodiment are marked with the same reference numerals as in the first embodiment. In particular, the reference numerals have the same meanings as have been explained in conjunction with the first embodiment. It is understood that all previous explanations of the first embodiment also apply to the second embodiment in the same way or in a similarly identical way.

[0092] In the second embodiment, the actuating device 6 is designed so that the mechanical force acts on a region of the pump housing 52 arranged outside the cup-shaped recess 121 of the stator 100. Since the mechanical force does not directly act on the cup-shaped recess 121 or the cup 531 of the pump housing 52 in the second embodiment, the second embodiment also does not require a centrally arranged opening 103 in the stator 100.

[0093] In the second embodiment, the actuating device 6 comprises a mounting device 70, which can be fixed to the first axial end 101 of the stator 100, for example, by means of a plurality of fixing screws 75. The mounting device 70 comprises an annular base 71, which is designed so that it can surround the pump housing 52 and in particular the cup 531 of the pump housing 52. The annular base 71 is attached to the first axial end 101 of the stator 100 by means of the fixing screws 75, so that the annular base 71 is arranged around the cup-shaped recess 121. Then, the cup 531 of the pump housing 52 can be inserted into or removed from the cup-shaped recess 121 through the annular base 71.

[0094] Several (here four) guide elements 72 are arranged on the annular base 71, each of which extends from the annular base 71 away from the stator 100 in the axial direction A. Each guide element 72 is designed in a rod-shaped manner here. The guide elements 72 are arranged so that the pump housing 52 of the pump unit 50 is guided between the guide elements 72 in the axial direction A. Optionally, a groove 74 extending in each case in the axial direction A can be provided on the pump housing 52 for each guide element 72, in which groove the corresponding guide element 72 engages. In doing so, a twisting of the pump housing 52 relative to the mounting device 70 can be effectively avoided.

[0095] Furthermore, several attachment elements 77 are provided at the pump housing 52, with which the pump housing 52 can be fixed to the mounting device 70. The attachment elements 77 are designed, for example, as fixing screws 77, which are arranged at the pump housing 52. For each fixing screw 77, an internal thread 78 is provided on the annular base 71 in each case, into which the respective fixing screw 77 engages. In this way, the pump unit 50 can be reliably attached to the mounting device 70.

[0096] The mounting device 70 includes a plurality of elastic elements 79 arranged so that when the pump unit 50 is fixed in the stator 100, the elastic elements 79 are tensioned in the axial direction A. This means that when the pump unit 50 is inserted into the cup-shaped recess 121 and the fixing screws 77 are tightened, the elastic elements 79 are tensioned. Therefore, the pump unit 50 is inserted into the cup-shaped recess 121 against the elastic force of the elastic elements 79. Figure 7 The pump unit is shown in the inserted state.

[0097] If the pump unit 50 is now to be replaced, the fixing screws 77 are loosened and the tensioned spring elements 79 push the pump unit 50 in the axial direction A out of the stator 100 by their spring force.

[0098] Figure 6 A possible design and arrangement of the elastic element 79 is shown. Each of the guide elements 72 has on its radial inner side an axial groove 721 extending in the axial direction A. An articulated spring is arranged as an elastic element 79 in each axial groove 721. If the pump unit 50 is now inserted into the cup-shaped recess 121 by means of the mounting device 70 and attached with the fixing screw 77, the articulated spring is tensioned in the axial groove 721.

[0099] If the fixing screw 77 is loosened to replace the pump unit 50 , the pump unit 50 is pushed out of the stator along the guide element 72 by the spring force of the hinge spring acting in the axial direction A.

[0100] Of course, many other variations of the specific embodiments are possible. An essential aspect of the second embodiment is that the insertion of the pump unit 50 into the stator 100 is carried out against the force of the elastic elements 79, preferably against the force of the spring elements, so that when the pump unit 50 is fixed in the stator 100, these elastic elements 79 are tensioned in the axial direction A.

[0101] For example, an axial spring may also be provided between the pump housing 52 and the mounting device 70 .

[0102] Figure 8 A perspective view of a third exemplary embodiment of a device for replacing a pump unit 50 of a centrifugal pump 200 is shown, wherein the pump unit 50 is separated from the stator. Fig. 9 The third embodiment is shown after a first stage of insertion of the pump unit 50 into the stator 100 . Fig.10 The third embodiment is shown after the insertion of the pump unit 50 into the stator 100 is completed.

[0103] In the following, only the differences from the first and second embodiments will be discussed. The same components or functionally equivalent components of the third embodiment are marked with the same reference numerals as in the first and second embodiments. In particular, the reference numerals have the same meanings as have been explained in conjunction with the first and second embodiments. It is understood that all previous explanations of the first and second embodiments also apply to the third embodiment in the same way or in a similarly identical way.

[0104] In the third embodiment, the removal of the pump unit 50 from the stator 100 and the insertion of the pump unit 50 into the stator 100 are performed by means of a lever device.

[0105] exist Figure 8 , the pump unit 50 is shown separately from the stator 100. In the third embodiment, the actuating device 6 of the device 1 comprises a mounting ring 80, which can be fixed to the first axial end 101 of the stator 100, for example by means of a plurality of screws 801. The mounting ring 80 is designed so that it can surround the pump housing 52 and in particular the cup 531 of the pump housing 52. The mounting ring 80 is attached to the first axial end 101 of the stator 100 by means of the screws 801, so that the mounting ring 80 is arranged around the cup-shaped recess 121. Then, the cup 531 of the pump housing 52 can be inserted into or removed from the cup-shaped recess 121 by the mounting ring 80.

[0106] A first guide rod 81 and a second guide rod 82 are arranged on the mounting ring 80, each extending from the mounting ring 80 away from the stator 100 in the axial direction A. Preferably, the two guide rods 81, 82 are arranged along a diameter. A pivotable holding device 83 for holding the pump unit 50 is provided at the first guide rod 81. The holding device 83 can be pivoted around the first guide rod 81. For this purpose, the holding device 83 has, for example, a first guide pin 831, which engages in the first guide rod 81 and can be rotated in the first guide rod 81. In addition, the first guide pin 831 can be displaced in the first guide rod 81 in the axial direction A.

[0107] The holding device 83 further includes a second guide pin 832 ( Fig. 9 ), the second guide pin 832 is preferably arranged diametrically relative to the first guide pin 831. In addition, for each guide pin 831, 832, a tensioning lever 85 is provided on the holding device 83 in each case, which can be adjusted in the open position ( Fig. 9 ) and closed position ( Fig.10 ) to move back and forth.

[0108] Figure 8 The holding device 83 is shown in a first position. From this first position, the holding device 83 can be pivoted about the first guide rod 81 into a holding position, preferably by 180°. Fig. 9 In the holding position, the holding device 83 rests against the second guide rod 82. The second guide pin 832 is now aligned with the second guide rod 82 so that when the holding device 83 is displaced in the axial direction A, the second guide pin 832 can engage in the second guide rod 82. This can be particularly Fig. 9 Recognized in.

[0109] The holding device 83 further has a holding opening 833, which is designed so that it can surround the pump housing 52 of the pump unit 50. The holding opening 833 is open on one side so that the holding device 83 can be pivoted on the pump unit 5 so that the pump housing 52 is arranged in the holding opening 833 of the holding device 83. The pump housing 52 and the holding opening 833 are designed so that when the pump housing 52 is arranged in the holding opening 833, the pump housing 52 can no longer be displaced in the axial direction A relative to the holding device 83.

[0110] Preferably, a removable protective sleeve 87 is provided at the pump housing 52, which surrounds the cup 531 of the pump housing 52 in an annular manner. The protective sleeve 87 has an outer diameter that is larger than the inner diameter of the cup-shaped recess 121, so that the pump unit 50 cannot be accidentally pulled into the cup-shaped recess 121. The protective sleeve 87 is preferably designed in two parts, for example with two half shells ( Fig. 9) so that the protective sleeve 87 can be easily removed from the cup-shaped portion 531 of the pump housing 52.

[0111] The protective cup 87 not only prevents the strong magnetic force from forcibly pulling the pump unit 52 into the stator 100 (thereby causing the pump unit 50 to be damaged by being forcibly pushed into the stator 100), but also prevents the cup 531 from being protected from being attracted by ferromagnetic objects, especially in the case of a rotor 51 designed in a permanent magnetic manner.

[0112] It is understood that the protective cup 87 can also be provided in other embodiments of the device 1 according to the invention.

[0113] In the following, reference Figures 8 to 10 The insertion of the pump unit 50 into the stator 100 is described. First, the retaining device 83 is in the Figure 8 The pump unit 50 with the protective cup 87 is arranged in the mounting ring 80 and rests on the first end 101 of the stator 100 .

[0114] Now, the holding device 83 is in Fig.10 , i.e. the holding device 83 is pivoted about the first guide rod 81 and on the pump unit 50 so that the pump unit 50 is held in the holding opening 833 of the holding device 83. The protective cup 87 is now removed. By actuating the tensioning lever 85, i.e. by tilting the tensioning lever 85 downwards by 180° (according to Fig. 9 ), the pump unit 50 is pushed into the cup-shaped recess in the stator 100 in the axial direction A.

[0115] In order to separate the pump unit 50 from the stator 100, the tensioning lever 85 is moved from the closed position ( Fig.10 ) to the open position ( Fig. 9 ), whereby the pump unit 50 is pulled out of the cup-shaped recess 121 in the axial direction A. Subsequently, the retaining device 83 is pivoted to the first position ( Figure 8 ) and the pump unit 50 can be removed.

[0116] Preferably, a locking element 88 is provided at the second guide rod 82, by means of which the retaining device 83 can be fixed to the first guide rod 81 when the pump housing 52 is arranged in the cup-shaped recess 121. The locking element 88 is designed, for example, as a locking pin with a snap-in function, which engages in a hole in the second guide pin 832 when the pump housing 52 is arranged in the cup-shaped recess 121.

[0117] exist Fig.11 and Fig.12 A variation on the third embodiment is shown in FIG. Fig.11 A perspective exploded view showing a variant of the third embodiment is shown, and Fig.12 A perspective view of a variant is shown. The pump unit 50 is similar to Figure 8 In a similar manner, it is shown separately from the stator 100.

[0118] For other embodiments, for example, for the second embodiment, in a similar manner, the variations described below are also possible. The variations are described here as examples for the third embodiment.

[0119] exist Fig.11 and Fig.12 In the variant shown in FIG. 1 , the stator 100 has a centrally arranged opening 103, which is combined with Figure 3 In a similar manner to that described, the actuating device 6 extends in the axial direction A from the second axial end 102 of the stator 100 to the cup-shaped recess 121. The centrally arranged opening 103 is designed in a cylindrical manner. In this variant, the actuating device 6 comprises a spring element 60, which is arranged in the centrally arranged opening 103. The spring element 60 is designed so that when the pump unit 50 is inserted into the cup-shaped recess 121, the spring element 60 is tensioned in the axial direction A. Therefore, when the pump unit 50 is inserted, the spring element 60 has a damping effect. When the pump unit 50 is separated from the stator 100, the spring element 60 facilitates the removal of the pump unit 50 from the cup-shaped recess 121 due to the spring force acting in the axial direction A.

[0120] For example, the spring element 60 is designed as a gas spring. Fig.11 As recognized in , the spring element 60 comprises a cylinder 602 in which a plunger 603 is arranged, which is movable in the axial direction A. A plate 601 is arranged at the end of the plunger 603, which is arranged outside the cylinder 602 and is located in the cup-shaped recess 121. The cup-shaped recess 121 is provided at its bottom with a channel through which the plunger 603 extends. When the pump unit 50 is inserted into the cup-shaped recess 121, the plate 601 and the plunger 603 are displaced in the direction of the cylinder 602, whereby the gas volume is compressed in the cylinder 602 in a manner known per se. This compression causes a spring force directed in the axial direction A in such a way that it attempts to displace the plate 601 in the direction of the first axial end 101 of the stator 100.

[0121] At the second axial end 102 of the stator 100 a base element 604 is provided which is fixed to the stator 100 and engages in the centrally arranged opening 103. The spring element 60 is supported on this fixed base element 604.

[0122] In the following, reference Figures 13 to 17 A fourth embodiment of the device 1 for replacing a pump unit 50 is explained. Fig.13 A perspective view of a fourth embodiment of the device 1 is shown. Fig.13 The pump unit 50 is not shown. Figures 14 to 17 The fourth embodiment is shown in each case in a perspective view in various stages of inserting a pump unit 50 into a stator 100 .

[0123] In the following, only the differences from the first, second and third embodiments will be discussed. The same parts of the fourth embodiment or parts equivalent in function are marked with the same reference numerals as in the previously described embodiments. In particular, the reference numerals have the same meanings as have been explained in conjunction with the first, second and third embodiments. It is understood that all previous explanations of the first, second and third embodiments also apply to the fourth embodiment in the same way or in a similarly identical way.

[0124] In a fourth embodiment of the device 1 according to the invention, the pump unit 50 is fixed in the stator 100 via a bayonet connection. For this purpose, the device 1 comprises a bayonet ring 90, which can be fixed to the first axial end 101 of the stator 100, so that the bayonet ring 90 is arranged around the cup-shaped recess 121. The bayonet ring 90 is designed for bayonet connection to the pump housing 52 of the pump unit 50. For this purpose, the bayonet ring 90 comprises a plurality of claws 91, which are designed to engage with the protrusions 92 ( Fig.14 ) interaction, wherein the projection 92 is arranged at the outer side of the pump housing 52. In addition, a plurality of receiving grooves 93 are provided in the radial inner surface of the bayonet ring 90, by means of which a bayonet connection between the pump housing 50 and the bayonet ring 90 can be formed and released.

[0125] The bayonet ring 90 is attached to the first axial end 101 of the stator by means of a plurality of fixing screws 94 , such that the bayonet ring 90 is securely connected to the stator 100 .

[0126] Particularly preferably, the bayonet ring 90 is designed in such a way that the pump housing can be fixed in the bayonet ring 90 by a rotational movement relative to the bayonet ring 90 about the axial direction A, a subsequent movement in the axial direction A and a subsequent rotational movement about the axial direction A. Both rotational movements take place in the same direction. For this purpose, the receiving groove 93 in the bayonet ring 90 is designed accordingly. This can be Fig.13 After the pump housing has been inserted into the receiving groove 93, the pump housing 52 must first be rotated about the axial direction A relative to the bayonet ring 90 before the pump housing 52 can be moved in the receiving groove 93 in the axial direction A toward the stator 100. After completing this linear movement, the pump housing 52 must be rotated about the axial direction A relative to the bayonet ring 90 again so that the claws 91 of the bayonet ring 90 engage with the protrusions 92 at the pump housing 52, whereby the pump unit 50 is fixed in the bayonet ring 90. The release of the pump unit 50 is performed in the reverse order.

[0127] Preferably, a securing pin 95 is also provided at the bayonet ring 90, which engages in a recess in the pump housing 52 as soon as the pump housing 52 is secured in the bayonet ring 90. The securing pin 95 has a snap-in function known per se, i.e. the securing pin 95 automatically engages in a recess in the pump housing 52 as soon as the pump housing 52 is in a position in which the pump housing is secured in the bayonet ring 90. In order to separate the pump unit 50 from the stator again, the securing pin 95 must first be pulled out of the recess in the pump housing 50 by hand before the bayonet connection can be released. The securing pin 95 thus prevents an unintentional separation of the pump unit 50 from the stator 100.

[0128] refer to Figures 14 to 17 The formation of the bayonet connection between the pump unit 50 and the stator 100 is explained. First, the pump unit is inserted into the bayonet ring 90 in the axial direction A so that Fig.14 Now, according to Fig.14 and Fig.15 As shown in FIG. 1 , the pump unit 50 is rotated clockwise around the axial direction A until the pump housing 50 rests against the nose 931 defining the receiving groove 93. This state is Fig.15 Subsequently, the pump unit 50 moves in the axial direction A toward the first axial end 101 of the stator 100. After this movement in the axial direction A, the pump unit 50 is in Fig.16 Then, according to Fig.16 and Fig.17 As shown in FIG. 1 , the pump unit 50 rotates clockwise around the axial direction A. Due to this rotational movement, the claw 91 of the bayonet ring 90 engages with the protrusion 92 at the pump housing 52, the nose 931 surrounds the outlet 524 of the pump housing 52, and the fixing pin 95 engages in the recess in the pump housing 52. This state is Fig.17 In this position, the pump unit 50 is fixed in the bayonet ring 90 and is protected against unintentional release.

[0129] In the fourth embodiment, with reference Fig.11 and Fig.12 The actuating device 6 is designed in a similar manner to the variant of the third embodiment explained. The actuating device 6 therefore comprises a spring element 60 which is arranged in a centrally arranged opening 103 of the stator 100 .

[0130] The spring element 60 is designed such that when the pump unit 50 is inserted into the cup-shaped recess, the spring element 60 is tensioned in the axial direction A. Therefore, the spring element 60 has a damping effect when the pump unit 50 is inserted. When the pump unit 50 is separated from the stator 100, the spring element 60 causes (or at least facilitates) the removal of the pump unit 50 from the cup-shaped recess 121 by the spring force acting in the axial direction A.

[0131] The spring element 60 is designed as a gas spring, for example, and comprises a cylinder 602, in which a plunger 603 is arranged, which can be moved in the axial direction A. A plate 601 located in a cup-shaped recess 121 is arranged at the end of the plunger 603, which is arranged outside the cylinder 602. The cup-shaped recess 121 is provided at its bottom with a channel through which the plunger 603 extends. When the pump unit is inserted into the cup-shaped recess 121, the plate 601 and the plunger 603 are displaced in the direction of the cylinder 602, whereby the gas volume is compressed in the cylinder 602 in a manner known per se. This compression causes a spring force directed in the axial direction A in such a way that it displaces the plate 601 in the direction of the first axial end 101 of the stator 100. At the second axial end 102 of the stator 100 a base element 604 is provided which is fixed to the stator 100 and engages in the centrally arranged opening 103. The spring element 60 is supported on this fixed base element 604.

Claims

1. A device for replacing a pump unit (50) of a centrifugal pump (200), the centrifugal pump (200) comprising the pump unit (50) and a stator (100) extending in an axial direction (A) from a first axial end (101) to a second axial end (102), wherein: A cup-shaped recess (121) is provided at the first axial end (101), into which the pump unit (50) can be inserted, wherein the pump unit (50) comprises a pump housing (52) having a cup-shaped portion (531), which can be inserted into the cup-shaped recess (121) of the stator (100), wherein a rotor (51) for conveying a fluid is arranged in the pump housing (52), the rotor having a magnetically effective core (511), wherein the rotor (51) can rotate about the axial direction (A), and wherein, The stator (100) is designed for non-contact magnetic drive and non-contact magnetic suspension of the rotor (51), wherein the rotor (51) is passively magnetically stabilized relative to the stator at least in the axial direction (A), characterized in that the device includes an actuator (6) by which a mechanical force can be applied to the pump unit (50), wherein the mechanical force acts in the axial direction (A) and is oriented in such a way that the mechanical force separates the pump unit (50) from the stator (100) in the axial direction (A).

2. The device according to claim 1, wherein: The actuating device (6) is designed so that the mechanical force acts on the cup-shaped recess (121) in the stator (100) or on the cup-shaped portion (531) of the pump housing.

3. A device according to any one of the preceding claims, wherein: The actuating device (6) comprises a piston (61) which can be displaced in an axial direction (A), wherein the piston (61) can be inserted into a centrally arranged opening (103) in the stator (100), and the displacement of the piston (61) relative to the stator (100) generates the mechanical force that separates the pump unit (50) from the stator (100) in the axial direction (A).

4. A device according to any one of the preceding claims, wherein: The device comprises a guide rail (66) which can be fixed to the stator (100), and wherein a support element (67) which is displaceable in an axial direction (A) is arranged on the guide rail (66), and when the pump unit (50) is separated from the stator (100), the support element protects the pump unit (50) from tilting.

5. A device according to any one of the preceding claims, wherein: The actuating device (6) is designed such that the mechanical force acts on a region of the pump housing (52) that is arranged outside the cup-shaped recess (121) of the stator (100).

6. A device according to any one of the preceding claims, wherein: The actuating device (6) comprises a spring element (60) which can be inserted into a centrally arranged opening (103) in the stator (100), wherein the spring element (60) is designed such that when the pump unit (50) is inserted into the cup-shaped recess (121), the spring element (60) is tensioned in the axial direction (A).

7. A device according to any one of the preceding claims, comprising a mounting device (70) which can be fixed to the first axial end (101) of the stator (100), wherein: The mounting device (70) has an annular base (71) which is designed to surround the pump housing (52), wherein a plurality of guide elements (72) are arranged on the base (71) so as to guide the pump housing (50) into the cup-shaped recess (121) of the stator (100) in an axial direction (A), wherein a plurality of attachment elements (75) are provided for fixing the pump housing (52), and wherein the mounting device (70) includes a plurality of elastic elements (79) which are tensioned in the axial direction (A) when the pump unit (50) is fixed in the stator (100).

8. The device according to any one of claims 1 to 6, comprising a mounting ring (80) which can be fixed to the first axial end (101) of the stator (100) such that the mounting ring (80) is arranged around the cup-shaped recess (121), wherein: A first guide rod (81) and a second guide rod (82) are arranged on the mounting ring (80), each of which extends in an axial direction (A), wherein a pivotable retaining device (83) for retaining the pump unit (5) is provided at the first guide rod (81), the retaining device being pivotable to a retaining position in which the retaining device (83) rests against the second guide rod (82), and wherein at least one tensioning lever (85) is provided, by actuation of which the retaining device (83) can be displaced in the axial direction (A) along the guide rods (81, 82).

9. The device according to claim 8, wherein: A locking element (88) is provided at one of the guide rods (82), by means of which the retaining device (83) can be fixed to the guide rod (82) when the pump housing (52) is arranged in the cup-shaped recess (121).

10. The device according to any one of claims 1 to 6, comprising a bayonet ring (90) which can be fixed to the first axial end (101) of the stator (100) such that the bayonet ring (90) is arranged around the cup-shaped recess (121), wherein: The bayonet ring (90) is designed for bayonet connection to the pump housing (52) of the pump unit (50).

11. The device according to claim 10, wherein: The bayonet ring (90) is designed in such a way that the pump housing (52) can be fixed in the bayonet ring (90) by a rotational movement relative to the bayonet ring (90) about the axial direction (A), a subsequent movement in the axial direction (A) and a subsequent rotational movement about the axial direction (A).

12. The device according to any one of claims 10 to 11, wherein: A fixing pin (95) is provided at the bayonet ring (90), and when the pump housing (52) is arranged in the cup-shaped recess (121), the pump unit (50) can be fixed in the bayonet ring (90) by means of the fixing pin.

13. A centrifugal pump for conveying a fluid, comprising a pump unit (50) and a stator (100) extending in an axial direction (A) from a first axial end (101) to a second axial end (102), wherein: A cup-shaped recess (121) is provided at the first axial end (101), into which the pump unit (50) can be inserted, wherein the pump unit (50) comprises a pump housing (52) having a cup-shaped portion (531), which can be inserted into the cup-shaped recess (121) of the stator (100), wherein a rotor (51) for conveying the fluid is arranged in the pump housing (52), the rotor having a magnetically effective core (511), wherein the rotor (51) forms an electromagnetic rotary drive together with the stator (100), wherein the stator (100) is designed for non-contact magnetic drive and non-contact magnetic suspension of the rotor (51), wherein the rotor (51) is passively magnetically stabilized at least in the axial direction (A), and characterized in that a device for replacing the pump unit (50) designed according to any of the preceding claims is provided.

14. The centrifugal pump according to claim 13, wherein: The device (1) for replacing the pump unit (50) is designed such that the device (1) can in each case be removed from the centrifugal pump (100) after the pump unit (50) has been replaced.

15. A centrifugal pump according to any one of claims 13 to 14, wherein: The electromagnetic rotary drive is designed as a temple motor, wherein the stator (100) has a plurality of coil cores (125), each of the plurality of coil cores comprising a longitudinal leg (126) and a transverse leg (127), the longitudinal leg extending in an axial direction (A) from a first end to a second end, the transverse leg being arranged at the second end of the longitudinal leg (126) and extending in a radial direction perpendicular to the axial direction (A), wherein the coil core (125) is arranged around the rotor (51) with respect to a circumferential direction, so that the rotor (51) is arranged between the transverse legs (127) of the coil core (125), and wherein at least one concentrated winding (160, 161) is provided at each longitudinal leg (126), the winding surrounding the corresponding longitudinal leg (126).

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