Pump housing, and pump

Abstract

The invention relates to a pump housing (1), in particular of a blood pump, comprising a pump chamber (1c) in which a rotor (2) is arranged which can be rotated about an axis of rotation (3) and by means of which a fluid can be conveyed from an inlet (4) of the pump housing (1) to an outlet (6) of the pump housing (1), wherein the pump chamber (1c) comprises an outlet chamber (5) which is arranged in a region radially outside around the rotor (2) and which opens into the outlet (6), wherein a fluid chamber (7) is arranged radially outside around the outlet chamber (5) and is separated from the outlet chamber (5) by a chamber wall (8) which is movable at least in regions. The invention also relates to a pump comprising such a pump housing (1) and a drive by means of which the rotor (2) can be driven in the pump housing (1), preferably wherein the rotor (2) is driven by the drive through a wall of the pump housing (1) by means of magnetic interaction.

Description

[0001] Pump housing and pump

[0002] The invention relates to a pump housing, in particular a blood pump, comprising a pump chamber in which a rotor rotatable about an axis of rotation is arranged, with which a fluid can be conveyed from an inlet of the pump housing to an outlet of the pump housing, wherein the pump chamber comprises an outlet chamber which is arranged in a region radially outwardly around the rotor and which opens into the outlet.

[0003] The invention further relates to a pump, in particular a blood pump with such a pump housing.

[0004] Such a rotor is preferably rotatably mounted, e.g., on or by means of a contact-based bearing located in the pump chamber, e.g., on a shaft or a ball or spherical surface. Such a rotor can be at least rotatably mounted in a non-operating pump housing, which in particular means that the rotor is only stably mounted for rotation about the rotational axis during operation of a pump encompassing the pump housing.

[0005] This is the case, for example, if the rotor is not stably or indifferently mounted in the non-rotating case and the rotor only reaches the state of stable rotatable mounting in this operating situation through a magnetic interaction in an operating situation and / or through a hydrodynamic interaction with the pumped fluid in an operating situation, in particular in each case together with a contact-based bearing.

[0006] In particular, this is preferably the case with blood pumps in which blood flows around the rotor during operation, which at least contributes to the hydrodynamic bearing and / or the rotor is held in a floating state in the pump housing or in a rotatable state supported on a contact-based bearing, in particular being set in rotation, by at least one magnetic field acting on the rotor, e.g. a magnetic field that absorbs tilting moments.

[0007] For this purpose, it can preferably be provided that at least one rotating magnetic field generated by a drive of a pump acts through at least one wall of the pump housing, in particular the wall of the base, on the rotor, in particular on magnetic or at least magnetizable elements integrated therein, e.g. permanent magnets.

[0008] The invention described below is preferably used in blood pumps, but can in principle be used in pumps of any kind.

[0009] The outlet chamber of a pump housing, in particular of a pump housing according to the invention, is often also referred to in technical terms or in English as a “volute”. In particular, this refers to a spatial region of the pump chamber which is arranged outside the rotor or around the blade ends at least in an axial height region in which the blades of the rotor are located, or in an axial region of the entire axial extent of the rotor. In the direction of rotation during operation or in the intended direction of rotation of the rotor, this outlet chamber opens into the outlet of the pump housing. In particular, the pumped fluid is thus pumped from the inlet of the pump housing, which is preferably located axially in front of the blades of the rotor, with the blades radially outwards and in the circumferential direction around the axis of rotation / the rotor towards the outlet.

[0010] The terms "axial" or "radial" or "circumferential direction," and in particular other directional terms, are preferably to be understood with respect to the rotor's axis of rotation, in particular the axis the rotor assumes at least in a stable operating situation. The inlet and / or outlet can preferably be designed as nozzles on the pump housing in the invention. The inlet nozzle is preferably coaxial with the axis of rotation. The outlet nozzle is preferably tangential or at least substantially tangential to the radially outer wall of the outlet chamber.

[0011] In a known embodiment, which can also be provided in the invention, such an outlet space can expand at least in some regions with increasing circumferential angle in the radial direction, in particular also in the axial direction.

[0012] In the case of a radial expansion, the outlet chamber is spiral-shaped, at least in some areas. Outlet chambers shaped in this way are often also referred to as spiral chambers. In another embodiment, which can also be provided in the invention, the outlet chamber is provided with no radial and / or axial expansion.

[0013] Pumps of this type, in which the pumped fluid is accelerated radially outwards, in particular so-called radial pumps, are used in medical technology, for example, to pump blood in order to replace a patient's heart or at least to support it temporarily during recovery.

[0014] These pumps are characterized by the fact that they are often used over a wide operating point range, even though they are designed for only one fixed operating point, known as the design point. Operating blood pumps outside the design point can be associated with complications such as hemolysis or thrombus formation, e.g., due to blood recirculation.

[0015] Against this background, it is an object of the invention to provide a pump housing of the type mentioned at the outset and a pump with such a pump housing, in which the geometry of the pump housing can be adapted to changing operating points.

[0016] According to the invention, this object is achieved in a pump housing mentioned at the outset in that a fluid chamber is arranged radially outside around the outlet space, which fluid chamber is separated from the outlet space by a chamber wall which is at least partially movable.

[0017] The invention can be provided in such a way that the movable chamber wall can be moved, in particular displaced, by changing the pressure difference between the sides radially on both sides of the chamber wall.

[0018] Preferably, the movable chamber wall is movable, in particular displaceable, by a pressure change in the outlet chamber. Such a pressure change can be caused, for example, by changing the speed of the rotor or generated externally through the inlet or outlet. Preferably, it can also be provided that the movable chamber wall is movable, in particular displaceable, by a pressure change in the fluid chamber.

[0019] It is preferably provided that the chamber wall is designed to be movable over its entire circumferential extent around the axis of rotation, in particular over 360 degrees.

[0020] The object is achieved in a pump mentioned above in that this pump comprises a pump housing according to the invention and a drive with which the rotor can be driven in the pump housing, preferably with the drive driving the rotor through a wall of the pump housing by means of magnetic interaction, which opens up the preferred use as a blood pump. According to the invention, the outlet space of the pump housing is thus delimited radially outwardly not by rigid walls of the pump housing, but rather by the aforementioned movable chamber wall.

[0021] Preferably, the invention can be effected in such a way that, upon a reduction in the pressure in the fluid chamber, in particular relative to the pressure in the outlet chamber, the chamber wall is moved in a direction away from the axis of rotation, and upon an increase in the pressure in the fluid chamber, in particular relative to the pressure in the outlet chamber, the chamber wall is moved in the direction of the axis of rotation or toward the rotor or the blades. Thus, in the first case, the free cross-section of the outlet chamber can be increased, and in the second case, the free cross-section of the outlet chamber can be reduced.

[0022] A pump according to the invention preferably has a control device with which the pressure in the fluid chamber and / or in the outlet chamber can be changed. Such a change can be made independently / without knowledge of the currently prevailing pressure in the fluid chamber and / or in the outlet chamber, or dependently / with knowledge of the currently prevailing pressure in the fluid chamber and / or in the outlet chamber, e.g., after measuring the pressure in the fluid chamber and / or in the outlet chamber.

[0023] The hydraulic properties of a pump with a pump housing according to the invention can thus be changed by geometric changes in the pump housing, in particular during operation of the pump, which is particularly advantageous in blood pumps.

[0024] The operating behavior of pumps, preferably blood pumps, can be adjusted, for example, by changing the outlet chamber cross-section. For example, the operating behavior of blood pumps can be adapted to different recovery states of a diseased heart. The aforementioned adjustments can preferably be made actively, e.g., by a previously mentioned control device, or passively, e.g., by the pressure change in the fluid chamber and / or the outlet chamber that occurs automatically when the operating point changes.

[0025] The change in pressure in the fluid chamber and / or the outlet chamber can be achieved by any means, e.g., by a volume-changing element arranged in the fluid chamber, which can change its volume through an external, e.g., electrical, control. Such a volume-changing element can be part of the aforementioned control device.

[0026] However, it is particularly preferred in the invention that the pump housing has a chamber connection opening into the fluid chamber, through which a fluid can be introduced into the fluid chamber, e.g. injected, or led out of the fluid chamber, e.g. sucked out.

[0027] In one possible embodiment, the fluid chamber can be open to the environment or to a passive fluid reservoir through the chamber connection, in particular so that the movement of the chamber wall occurs purely passively through the hydraulic pressure on the blood side (radially inward of the chamber wall), in particular against the material elasticity of the chamber wall.

[0028] An increase in pressure in the fluid chamber can also be achieved by injecting fluid into the fluid chamber and a reduction in pressure by sucking fluid out of the fluid chamber. Injection or suction can preferably be performed actively using an actuator. For this purpose, a pump device can preferably be connected to the aforementioned chamber connection. This can, for example, be part of the aforementioned control device.

[0029] The fluid used is preferably an incompressible fluid, and in the case of blood pumps, an aqueous sodium chloride solution is preferred.

[0030] A preferred embodiment provides that pressure changes, in particular passively occurring and / or actively generated pressure changes in the fluid chamber and / or the outlet chamber, can change the shape of the chamber wall, viewed in cross-section parallel to the axis of rotation, between concave to the rotor and convex to the rotor, in particular starting from a rectilinear chamber wall existing without a pressure difference between the fluids on either side of the chamber wall. In particular, the chamber wall is understood to be convex to the rotor if it is bulged toward the rotor, in particular between two fastening points.

[0031] It can be provided that a state in which the chamber wall is concave to the rotor can exist such that the radially outer surface of the chamber wall, i.e., the one facing into the fluid chamber, contacts the radially outer inner surface of the fluid chamber. This is particularly achievable when all fluid has been removed from the fluid chamber, e.g., pumped out or forced out. In this way, the maximum possible internal cross-section of the outlet chamber is defined.

[0032] In a possible preferred embodiment, the chamber wall is formed from an elastomer, in particular silicone. This enables movement of the chamber wall through reversible expansion of the chamber wall, starting from a relaxed state of the chamber wall. In particular, in such a relaxed state, the chamber wall, viewed in cross-section parallel to the rotor's axis of rotation, is rectilinear.

[0033] In another possible preferred embodiment, the chamber wall is formed from a plastic or metal foil. Movement of the chamber wall is preferably enabled by the chamber wall being stretchable, starting from a state in which the chamber wall is secured between two axially spaced-apart fastening points with an axial oversize.

[0034] A preferred embodiment of the chamber wall provides that it is formed by a ring that is completely closed in the circumferential direction around the axis of rotation, wherein a pipe socket is arranged on the ring, in particular arranged tangentially to the chamber wall, which opens radially inward into the chamber wall, preferably wherein the pipe socket is formed integrally with the ring.

[0035] Particularly preferably, the pipe socket is made of the same material as the ring. Thus, the ring can be molded together with the pipe socket, e.g., by injection molding an elastomer, preferably silicone.

[0036] A preferred further development then provides that the outlet of the pump housing is formed by an outlet nozzle in which the pipe nozzle of the ring lies at least in part.

[0037] In order to achieve a fluid-tight transition between the outlet nozzle and the pipe nozzle, the invention preferably provides that a connector is inserted into the free end of the outlet nozzle, which connector contacts the inner wall of the outlet nozzle with a first axial section and contacts the inner wall of the pipe nozzle of the ring with a second axial section, which has a smaller cross-section than the first section.

[0038] By contacting the inner wall of the pipe socket of the ring, it is further achieved that this pipe socket is expanded from the inside and thus the outer wall of this pipe socket is pressed tightly against the inner wall of the outlet socket of the pump housing.

[0039] Preferably, the connector has a connection piece at its free end, to which subsequent components can be connected. A preferred development provides that the ring forming the chamber wall has fastening elements at both axial ends, with which the ring can be secured in the pump housing.

[0040] In this case, a respective fastening element is preferably designed as an annular material thickening (in particular in comparison to the other wall regions between the two axial ends), which lies in a respective annular recess in the pump housing, in particular in a force-fitting manner, preferably which is glued in the recess or to an edge region of the recess.

[0041] Furthermore, it is provided in all possible embodiments that the pump housing is designed in several parts, preferably in two parts, and comprises at least a lower housing pot and an upper housing cover.

[0042] With reference to the aforementioned embodiment, the preferred implementation of this fastening design provides for an annular groove in the housing cup and an annular groove in the housing cover. The attached chamber wall then extends between these two annular recesses, in particular with the axially end-side material thickenings being located in a respective associated groove.

[0043] Preferably, the lower housing pot surrounds the majority of the rotor in the axial direction, in particular, it completely surrounds the part of the rotor located below the blades of the rotor. Further preferably, an axially lower portion of the blades, in particular precisely the lower half of the blades, is surrounded by the housing pot.

[0044] The housing cover preferably surrounds an axially upper portion of the rotor blades, in particular an upper half. Further preferably, the housing cover and housing pot each partially enclose the outlet, in particular the outlet connection of the pump housing, in particular in half.

[0045] Preferably, the housing pot and the housing cover are connected to one another in a connecting plane perpendicular to the axis of rotation, wherein the connecting plane intersects the chamber wall, preferably between the material thickenings, and / or axially centrally.

[0046] Preferred embodiments of the invention are described with reference to the figures.

[0047] Figure 1 shows an exploded view and Figure 2 shows a sectional view of a pump housing 1 and a pump constructed therewith, in particular a blood pump, according to the invention, wherein the pump housing 1 comprises a lower pump chamber 1a and an upper pump cover 1b. A rotor 2 is arranged in the pump chamber 1c of the pump housing 1 and is mounted for rotation about the axis of rotation 3. The rotor 2 is preferably supported by contact on a spherical surface of a bearing ball 2b arranged in the pump chamber 1a, against which the rotor 2 is supported, here preferably on the underside and on the side of the rotor 2 facing away from the inlet 4.

[0048] The embodiment of the invention is not limited to the type of bearing shown, since the bearing of the rotor 2 is fundamentally irrelevant to the invention. Other types of bearing are also possible, e.g., on a shaft or purely hydrodynamically.

[0049] The rotor 2 carries on its upper side, opposite the pump cover 1b, a plurality of blades 2a, with which, when the rotor 2 rotates, a fluid to be pumped is pumped from the inlet 4 through the outlet chamber 5 to the outlet 6. Inlet 4 and outlet 6 are preferably designed as nozzles on the pump housing 1. The blades 2a can also be covered by a cover (not provided here) which has an upper passage, preferably which is aligned with the inlet 4. The figures show the pump housing 1 of a pump preferably designed as a blood pump. In this case, the rotor 2 is contact-mounted in the pump housing 1 and is additionally magnetically mounted, but in particular is magnetically driven.

[0050] Magnetically acting elements provided for the magnetic drive in the rotor 2 are formed in its interior, for example, as permanent magnets 2c, which interact with a rotating magnetic field of the drive 20 acting from outside the pump housing 1. The drive 20 preferably has a housing in which a drive disk 20b is set in rotation by an electrically operated motor 20a, into which drive magnets 20c (e.g.

[0051] Permanent magnets) are integrated, so that the rotating drive disk 20b generates a rotating magnetic field that acts on the permanent magnets 2c of the rotor 2, in particular to drive it, preferably with tilting moments around the contact-based bearing on the ball 2b being absorbed. The speed of the motor 20a is controlled / regulated via the power supply and / or signal supply 20d.

[0052] Here, the rotor 2 preferably has a central bore, in particular one that is open around the contact-based bearing on the ball 2b, so that blood can also circulate around the rotor 2 through the bore. This can be provided, for example, to prevent stagnation in the lower gap and / or to form a hydrodynamic bearing function and / or to dissipate heat from the contact-based bearing. The central bore shown here is not essential to the invention and can also be omitted in other embodiments.

[0053] It is essential to the invention that a fluid chamber 7 is arranged radially outwardly around the outlet chamber 5. The outlet chamber 5, which is a partial region of the pump chamber 1c, and the fluid chamber 7 are separated by a chamber wall 8, which is designed as a ring closed by a full 360 degrees around the axis of rotation 3, on which a pipe socket 8a is arranged, which is preferably oriented at least substantially tangentially to the chamber wall 8 and opens into its inner surface, thus being in fluid communication with the pump chamber 1c.

[0054] At the two axial ends of the annular chamber wall 8, it has fastening elements 8b designed as material thickenings (particularly with a square cross-section), which are adhesively secured in respective annular recesses 9 in the pump housing 1a and pump cover 1b with an adhesive seam 12. These material thickenings are shown enlarged in detail A of Figure 2. They preferably have a square cross-section.

[0055] The detailed enlargement A of the sectional view of Figure 2 further shows that the pump pot 1a and the pump cover 1b are connected in a connecting plane E, e.g. materially bonded, which intersects the annular chamber wall 8, in this embodiment preferably centrally or at least between the fastening elements 8b.

[0056] The fluid chamber 7, formed radially outwardly by the chamber wall 8 and between the chamber wall 8 and the pump housing 1, has a chamber connection 10, which is guided through the wall of the pump housing 1 and serves to pump a fluid into or out of the fluid chamber, thereby changing the pressure in the fluid chamber 7 and thus generating a displacement of the chamber wall 8 compared to a relaxed state in which no displacing force acts on the chamber wall. In such a relaxed state, the chamber wall can preferably be straight between the fastening elements 8b or have another predefined shape.

[0057] For the pressure change, a control device 30 is preferably provided, in particular comprising a pumping device 31, which here is implemented as a piston syringe, the piston of which can be actuated by a drive. The control device 30, in particular the pumping device 31 or the internal volume of the piston syringe, is connected to the fluid chamber 7 via the connecting tube 32, so that fluid can be injected into the fluid chamber 7 or withdrawn from it.

[0058] The pipe socket 8a is located in the outlet 6 of the pump housing 1 and is sealed to it by a connector 11. The mounted position of the connector 11 is shown in Figures 3 and 4.

[0059] These Figures 3 and 4 further illustrate the function of the invention. In Figure 3, the fluid chamber 7 is at least partially filled with fluid, with the chamber wall 8 between the fastening elements 8b assuming an at least substantially rectilinear extension or only slightly bulged / convex extension toward the radially outer wall of the fluid chamber 7, or only slightly concave toward the rotor 2.

[0060] By pumping fluid into the fluid chamber 7, the chamber wall 8 can be caused to bulge in the direction of the rotor 2, whereby the cross section of the outlet chamber 5 is reduced.

[0061] Figure 4 shows a situation in which, compared to Figure 3, the fluid has been pumped out of the fluid chamber 7, in particular completely. Compared to Figure 3, Figure 4 shows a retracted position of the piston of the syringe. The chamber wall 8 is thereby displaced such that it is concave toward the rotor, in particular maximally concave, and in particular is in contact with the radially outer wall of the fluid chamber 7. As a result, the cross-section of the outlet chamber 5 is maximally enlarged.

[0062] By varying the filling levels of the fluid chamber 7, the geometry of the chamber wall 8 and thereby the cross-section of the outlet chamber 5 can be changed, whereby the pump housing 1 can be geometrically adapted to different operating points.

[0063] Figure 5 shows a change in the chamber wall compared to Figure 3, with an otherwise identical design. In the embodiment shown in Figure 3, this is preferably made of an elastomer, e.g., silicone, which allows the chamber wall to be movable / stretchable within its elastic range.

[0064] In contrast, in the embodiment of Figure 5, the chamber wall 8 is formed by a film, e.g., made of plastic or metal. Between the fastening elements 8b, the chamber wall 8 is formed with an oversize, in particular, which means that the axial length of the film / chamber wall 8 is greater than the axial distance between the fastening elements 8b. This allows the film / chamber wall to move into or out of the fluid chamber 7 between the fastening elements 8b, in particular with the film / chamber wall 8 lying between two extreme layers, e.g., folded or without a defined extension.

Claims

Patent claims 1. Pump housing (1), in particular of a blood pump, comprising a pump chamber (1c) in which a rotor (2) is arranged which is rotatable about an axis of rotation (3) and with which a fluid can be conveyed from an inlet (4) of the pump housing (1) to an outlet (6) of the pump housing (1), wherein the pump chamber (1c) comprises an outlet chamber (5) which is arranged in a region radially outward around the rotor (2) and which opens into the outlet (6), characterized in that a fluid chamber (7) is arranged radially outward around the outlet chamber (5), which is separated from the outlet chamber (5) by a chamber wall (8) which is movable at least in regions.

2. Pump housing according to claim 1, characterized in that the movable chamber wall is movable, in particular displaceable, by a. a pressure change in the outlet space (5), and / or b. a pressure change in the fluid chamber (7), in particular wherein the pump housing (1) has a chamber connection (10) opening into the fluid chamber (7), through which a fluid can be introduced, in particular injected, into the fluid chamber (7) or led out, in particular sucked out, from the fluid chamber (7), in particular by means of a pumping device.

3. Pump housing according to one of the preceding claims, characterized in that by pressure changes in the fluid chamber (7) and / or the outlet space (5) the shape of the chamber wall (8) at Viewed in cross section parallel to the axis of rotation (3) can be changed between concave to the rotor (2) and convex to the rotor (2), in particular starting from a chamber wall (8) which is present in a predefined form and preferably extends in a straight line on both sides of the chamber wall (8) without any pressure difference between the fluids.

4. Pump housing according to one of the preceding claims, characterized in that the chamber wall (8) is formed from one of the following materials: a. from an elastomer, in particular from silicone, in particular wherein a movement of the chamber wall (8) is made possible by reversible stretching starting from a relaxed state, b. from a plastic or metal foil, in particular wherein a movement of the chamber wall (8) is made possible by the chamber wall (8) being stretchable starting from a state in which the chamber wall (8) is fastened with an excess between two axially spaced fastening points (9).

5. Pump housing according to one of the preceding claims, characterized in that the chamber wall (8) is formed by a ring which is completely closed in the circumferential direction around the axis of rotation (3), wherein a pipe socket (8a) is arranged on the ring, in particular arranged tangentially to the chamber wall (8), which opens radially inward into the chamber wall (8), preferably wherein the pipe socket (8a) is formed integrally with the ring.

6. Pump housing according to claim 5, characterized in that the outlet (6) of the pump housing (1) is formed by an outlet nozzle in which the pipe nozzle (8a) of the ring lies at least in part.

7. Pump housing according to claim 6, characterized in that a. the pipe socket (a) of the ring and the outlet socket (6) are glued to one another in a fluid-tight manner, and / or b. a connector (11) is inserted into the free end of the outlet socket (6), which connector contacts the inner wall of the outlet socket (6) with a first axial section and contacts the inner wall of the pipe socket (8a) of the ring with a second axial section, which has a smaller cross-section than the first section.

8. Pump housing according to one of the preceding claims 5 to 7, characterized in that the ring has fastening elements (8b) at its two axial ends, with which the ring can be fastened in the pump housing (1).

9. Pump housing according to claim 8, characterized in that a respective fastening element (8b) is designed as an annular material thickening which lies in a respective annular recess (9) in the pump housing (1), in particular in a force-fitting manner, preferably in the recess (9) or is glued to an edge region of the recess (9).

10. Pump housing according to one of the preceding claims, characterized in that it is designed in several parts, preferably in two parts, and comprises at least one lower housing pot (1a) and one upper housing cover (1b).

11. Pump housing according to claim 10, characterized in that the housing pot (1a) and the housing cover (1b) are connected to one another in a connecting plane (E) lying perpendicular to the axis of rotation (3). wherein the connecting plane (E) intersects the chamber wall (8), preferably axially centrally.

12. Pump comprising a pump housing (1) according to one of the preceding claims and a drive with which the rotor (2) in the pump housing (1) can be driven, preferably, wherein the drive drives the rotor (2) through a wall of the pump housing (1) by means of magnetic interaction.

13. Pump according to claim 12, characterized in that it comprises a control device with which the pressure in the fluid chamber (7) can be changed.

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