CN218685727U - Magnetic-liquid double-suspension centrifugal blood pump - Google Patents

Abstract

The utility model discloses a two suspension centrifugal blood pumps of magnetism liquid includes: the device comprises an inlet pipeline, a pump cavity, a rotor, an impeller, a servo motor, a magnetic suspension bearing and a ceramic bearing; the servo motor comprises a stator component and rotor magnetic steel, the rotor and the impeller are integrated, the rotor is arranged in an inner tube of the blood pump, and the rotor drives the impeller to do work by the servo motor; the magnetic suspension bearing consists of an inner magnetic core group, an outer magnetic ring group and a magnetic ring group, and can generate radial magnetic suspension effect on the rotor and the impeller; the ceramic ball bearing consists of a ceramic ball and a ceramic wafer, and can play a role in supporting when the blood pump is started, so that the impeller cannot collide the wall and rub; the two ends of the impeller blade are provided with inclined planes, and a wedge-shaped groove is formed between the inclined planes and the inner surface of the pump cavity, so that hydraulic pressure can be generated when the pump works, and the impeller is subjected to liquid suspension. The utility model discloses an optimize the support bearing of blood pump, support bearing system is reliable and stable to improve the stability of work.

Description

Magnetic-liquid double-suspension centrifugal blood pump

Technical Field

The utility model relates to the technical field of medical equipment, specific saying so relates to a two suspension centrifugal blood pumps of magnetism liquid.

Background

The ventricle auxiliary device is an auxiliary artificial heart, which is also called a blood pump for short, and has been widely applied in clinic in recent years, and the clinical application amount is nearly ten thousand cases every year. At present, the most applied products in the international market are four major products in the United states, wherein two blood pumps are the second generation blood pumps, two blood pumps are the third generation blood pumps, and the second generation blood pump is of a mechanical bearing type structure, and the main defects are as follows: mechanical bearings are easy to wear, and the service life of the blood pump is seriously limited; because of bearing friction, the resulting hemolysis is relatively severe; the third generation blood pump is of a magnetic suspension type structure, and although the service life is long, the third generation blood pump also has new problems, namely the main problem: firstly, the magnetic suspension structure is complex, the volume of the blood pump is increased, and the invasiveness of the operation is increased, for example, the volume and the weight of a third-generation magnetic suspension blood pump HeartMate III are more than three times that of a second-generation blood pump Jarvik 2000; secondly, the structure is complex, blood flow dead angles and even dead spaces exist, and complications such as thrombus easily occur.

The utility model discloses a utility model patent of publication No. CN112473000A discloses a magnetic suspension centrifugal blood pump, and this utility model patent is the magnetic suspension blood pump, nevertheless because the magnetic suspension bearing is established at the front end of blood pump, and the main load of blood pump during operation is undertaken by the impeller in the rear end of pump, and this one end of impeller does not have radial suspension to support, therefore the holding power of axial suspension is obviously not enough, easy unstability when high-speed rotation.

Disclosure of Invention

In order to overcome the defects, the utility model provides a two suspension centrifugal blood pumps of magnetism liquid optimizes the support bearing of blood pump, and support bearing system is reliable and stable to improve the stability of work.

The utility model discloses a solve the technical scheme that its technical problem adopted and be:

a magnetic-liquid double-suspension centrifugal blood pump comprises a pump shell, a servo motor, a rotor, an impeller, a magnetic suspension bearing and a support bearing, wherein the pump shell comprises an inlet pipeline positioned above, and an upper pump cavity cover and a lower pump cavity cover positioned below;

the inlet pipeline is formed by sequentially sleeving an outer pipe, a middle pipe and an inner pipe, a pump inlet is formed in the upper end of the inlet pipeline and communicated with the inner pipe, the lower end of the inlet pipeline is hermetically connected with the pump cavity upper cover, the pump cavity upper cover is hermetically connected with the pump cavity lower cover, a pump cavity formed in the pump cavity upper cover is communicated with a cavity of the inner pipe, and a pump outlet communicated with the pump cavity is formed in the pump cavity lower cover;

the rotor is correspondingly arranged in the inner tube, an integrated impeller is arranged below the rotor, and the impeller is arranged in a pump cavity formed by sealing the pump cavity upper cover and the pump cavity lower cover;

the servo motor comprises rotor magnetic steel arranged in the rotor and a stator component arranged between a middle pipe and an inner pipe of the inlet pipeline, and the stator component drives the rotor and the impeller to respectively rotate in the inner pipe and the pump cavity to do work when being electrified;

the magnetic suspension bearing comprises an inner magnetic core group and an outer magnetic ring group which are respectively composed of annular magnetic sheets with the same number, the inner magnetic core group is arranged in the lower end of the rotor, and the outer magnetic ring group is arranged between a middle pipe and an inner pipe at the lower end of the inlet pipeline;

the support bearing comprises a ceramic ball and a ceramic pad, the ceramic ball is arranged at the bottom of the rotor, a boss is upwards arranged at the middle part of the lower cover of the pump cavity corresponding to the bottom of the rotor, and the ceramic pad is arranged on the boss.

As a further improvement, the utility model also includes a magnetic shielding group, which is composed of a shielding ring and a shielding ring, wherein the shielding ring is arranged in the rotor and above the inner magnetic core group, and the shielding ring is arranged between the middle pipe and the inner pipe of the inlet pipeline and above the outer magnetic ring group.

As a further improvement of the utility model, a support is arranged on the upper end parts of the inner pipe and the outer pipe of the inlet pipeline.

As a further improvement of the present invention, the stator assembly includes a stator winding, a stator core and a cable disposed between the inner tube and the outer tube of the inlet duct.

As a further improvement of the present invention, the rotor includes a rotor housing disposed outside the rotor magnetic steel.

As a further improvement of the utility model, the impellers are four and are evenly arranged below the rotor.

As a further improvement of the present invention, the upper side surface and the lower side surface of the blade of the impeller are respectively provided with an upper inclined surface and a lower inclined surface, the upper inclined surface and the lower inclined surface respectively and the pump cavity is formed with an upper wedge-shaped hydraulic pressure groove and a lower wedge-shaped hydraulic pressure groove therebetween.

As a further improvement of the utility model, the inclination angle of the upper inclined plane and the lower inclined plane is 3-10 degrees.

As a further improvement of the utility model, the inner magnetic core group and the outer magnetic ring group are respectively bonded together by two or three or four ring-shaped magnetic sheets which are in like-polarity repulsion.

As a further improvement of the utility model, a sewing ring is arranged on the outer side surface of the lower end of the outer pipe of the inlet pipeline.

The utility model has the advantages that:

the suspension bearing provided by the utility model is a permanent magnet bearing, belongs to passive magnetic suspension, does not need complex detection, feedback and control systems, has simpler structure and stable radial suspension performance; the two end surfaces of the impeller are subjected to hydraulic pressure, the axial liquid suspension effect is good, the radial suspension and the axial suspension are combined, the four-degree-of-freedom suspension of the impeller can be realized, and the technical reliability and the use safety of the blood pump can be greatly improved; the volume and the weight of the blood pump are smaller, so that the surgical invasiveness of the blood pump can be reduced, and the practicability is improved; the internal structure of the full-suspension blood pump is simple and smooth, has no dead space or dead angle, and can effectively prevent thrombosis.

Drawings

Fig. 1 is a schematic structural cross-sectional view of a magnetic-liquid double-suspension centrifugal blood pump according to an embodiment of the present invention;

FIG. 2 is a schematic structural view of a magnetic-liquid double-suspension centrifugal blood pump according to an embodiment of the present invention when starting;

fig. 3 is a schematic view of a rotation state of an impeller according to an embodiment of the present invention.

The reference numbers illustrate:

1. an inlet duct; 101. an outer tube; 102. a middle tube; 103. an inner tube; 104. a support; 105. a pump inlet; 2. a servo motor; 201. rotor magnetic steel; 202. a stator winding; 203. a stator core; 204. a cable; 3. a rotor; 301. a rotor housing; 4. an impeller; 401. a blade; 402. an upper inclined plane; 403. a lower inclined surface; 5. a pump chamber; 501. a pump cavity upper cover; 502. the inner surface of the upper cavity; 503. a pump cavity lower cover; 504. the inner surface of the lower cavity; 505. a boss; 506. an outlet of the pump; 6. a magnetic suspension bearing; 601. an outer magnetic ring set; 602. the inner magnetic core group; 7. a support bearing; 701. ceramic balls; 702. a ceramic pad; 8. an upper wedge groove; 9. a lower wedge groove; 10. a magnetic shield group; 1001. an inner shielding ring; 1002. an outer shield ring; 11. and (6) sewing the ring.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present disclosure more apparent, the technical solutions of the embodiments of the present disclosure will be described in detail below. It is to be understood that the embodiments described are only some of the embodiments of the specification and not all of them. All other embodiments obtained by a person of ordinary skill in the art without any inventive work based on the examples in the present specification fall within the scope of protection of the examples in the present specification.

The following further describes the concrete implementation of the embodiment with reference to the attached drawings of the embodiment in the specification.

Referring to fig. 1 to 3, an embodiment of the present specification provides a magnetic-liquid double-suspension centrifugal blood pump, including a pump system, a motor system, and a support system.

The pump system comprises an inlet conduit 1, a pump chamber 5, a rotor 3 and an impeller 4.

The inlet conduit 1 comprises an outer tube 1001, a middle tube 1002, an inner tube 1003, a bracket 1004, and a pump inlet 105.

The pump chamber 5 comprises a pump chamber upper cover 501, an upper chamber inner face 502, a pump chamber lower cover 503, a lower chamber inner face 504, a boss 505, and a pump outlet 506.

The rotor 3 is arranged at the center of the inner tube 1003; is connected with the impeller 4 at the lower end into a whole.

The impeller 4 comprises a plurality of blades 401, and the roots of the blades are connected with the rotor 3 and are uniformly distributed; the upper and lower end faces of the impeller are provided with an upper inclined surface 402 and a lower inclined surface 403 with an angle of 5-10 degrees.

Optionally, the impeller 4 comprises 3 blades or 4 blades or 5 blades or 6 blades.

The inlet support 104 is convex, so as to prevent the pump from working failure and embolism caused by the negative pressure sucking the ventricular septum when the blood pump works.

A cavity is formed between the outer pipe 101 and the middle pipe 102, so that the heat-resisting and cooling effects can be achieved, and the safe and effective work of the blood pump and the motor can be guaranteed.

A suture ring 11 is arranged on the outer tube 101 near the upper cover 501 of the pump cavity and is used for fixing the blood pump and the apex of the heart.

The pump cavity upper cover 501 is circular, the central opening is coaxially connected with the inner pipe 103, the outer circle is connected with the pump cavity lower cover 503, and the joint needs to be welded and leak-proof.

The pump cavity lower cover 503 has a boss 505 at the inner bottom and a pump outlet 505 at the side, and the pump cavity upper cover 501 is sealed and welded after the pump cavity lower cover 503 is fastened.

The rotor 3 is driven by the servo motor to drive the impeller 4 to do work, so that blood continuously flows in from the pump inlet 105, and flows out from the pump outlet 506 after being centrifuged.

The motor system is a servo motor 2, and the servo motor 2 mainly comprises rotor magnetic steel 201, a stator iron core 203, a stator winding 202 and a cable 204 which are positioned in a rotor 3.

Rotor magnetic steel 201 is arranged in rotor 3; the stator core 203 and the stator winding 202 are annular and are arranged in the interlayer of the middle pipe 102 and the inner pipe 103.

The cable 204 is disposed between the middle tube and the outer tube, and is used for transmitting electric energy and electric signals, one end of the cable is connected to the stator winding 202, and the other end extends to the outside of the body and is connected to a control system.

The servo motor 2 is integrated with the pump system, so that the pump-motor integration is formed.

The magnetic suspension bearing 6 comprises an outer magnetic ring group 601 and an inner magnetic core group 602, is positioned at the joint of the rear end of the rotor 3 and the impeller, and can provide radial suspension support, and the stability of the radial suspension of the rotor 3 and the impeller 4 is better because the position is in the middle section of the pump.

The ceramic bearing 7 includes ceramic balls 701 and ceramic pads 702.

The supporting system comprises a magnetic suspension bearing 6, a hydraulic structure and a ceramic bearing 7.

The magnetic suspension bearing 6 comprises an inner magnetic core group 1001 and an outer magnetic ring group 1002. The inner magnetic core group 1001 is formed by overlapping two round magnetic sheets together with the same axle center and is internally arranged at the top end inside the rotor; the outer magnetic ring group 1002 is formed by overlapping two magnetic rings together coaxially and sleeved on the outer wall of the inner pipe, and the axial installation position of the outer magnetic ring group is aligned with the central line of the inner magnetic core group 1001. The magnetic directions of the circular magnetic sheet and the magnetic ring are axial, and the stacking sequence is that the same poles are opposite and are bonded together forcibly.

Optionally, the inner magnetic core group 1001 may be formed by combining three circular magnetic sheets, and the outer magnetic ring group 1002 is formed by combining three magnetic rings; or the inner magnetic core group 1001 is formed by combining four round magnetic sheets, the outer magnetic ring group 1002 is formed by combining four magnetic rings, and the installation position is close to the lower edge.

Preferably, the magnetic material of the magnetic suspension bearing is strong magnetic neodymium iron boron.

The hydraulic structure is that the upper end and the lower end of each blade 401 of the impeller 4 are provided with an upper inclined surface 402 and a lower inclined surface 403, and an upper wedge-shaped groove 8 and a lower wedge-shaped groove 9 are respectively formed with an upper cavity inner surface 502 and a lower cavity inner surface 504, the space size of the two wedge-shaped grooves is variable, the space of the wedge-shaped groove is reduced when the end surface of the blade is close to the cavity inner surface, the space of the wedge-shaped groove is increased when the end surface of the blade is far away from the cavity inner surface, the flow inlet of the wedge-shaped groove is an inlet, the outlet is an outlet, the inlet is larger than the outlet, when the pump works, an incompressible liquid flow enters the wedge-shaped groove from the inlet, hydraulic pressure is generated due to extrusion, the impeller is higher in rotating speed, the included angle of the wedge-shaped groove is larger, the smaller is the larger is the hydraulic pressure, a set of opposite axial thrust is generated at the two ends of the blade 401 due to the hydraulic pressure, the impeller is axially suspended, and the set of force can be automatically adjusted along with the change of the upper and lower wedge-shaped space of the impeller, so the axial suspension is self-suspension.

Optionally, the included angle between the upper wedge-shaped groove 8 and the lower wedge-shaped groove 9 is 5-10 °.

The supporting system comprises a ceramic bearing, the ceramic bearing belongs to a temporary supporting point, the ceramic bearing comprises a ceramic ball 701 and a ceramic pad 702, the ceramic ball 701 is embedded at the lower end of the impeller 4, approximately half of the ceramic ball 701 is exposed, the top end of the boss 505 embedded in the ceramic pad 702 is flush with the edge of the boss, the ceramic ball 701 abuts against the ceramic pad 702 under the action of axial pressure generated by the magnetic suspension magnetic group to form a group of sliding bearings, and the magnetic suspension blood pump can be well supported and started.

In the magnetic-liquid double-suspension centrifugal blood pump provided by the embodiment of the specification, after the blood pump is started, if the impeller is required to be completely suspended and stably operated, firstly, the effect of radial suspension and axial suspension is mainly good, the design requirements of the limiting structures of the ceramic bearing and the pump cavity are reasonable, in addition, the dynamic balance requirements of the rotor and the impeller are precise, otherwise, the suspension of the rotor and the impeller is not good, and the vibration and noise are large.

Radial suspension is mainly realized by a magnetic suspension bearing 6, and an inner magnetic core group 1001 in a rotor and an outer magnetic ring group 1002 in a pump head stator are radially repelled due to magnetic force, so that the rotor and an impeller are radially centered and a radial suspension state is kept.

How to achieve axial suspension requires analysis of the axial force. The blood pump can receive the influence of a plurality of axial force when working, mainly includes, first axial force: the direction of the impulsive force of the liquid flow at the inlet of the pump to the rotor and the impeller is axial and downward, and the size of the impulsive force is positively correlated with the rotating speed; second axial force: the thrust generated by the pressure difference between the pump outlet and the inlet is in the axial direction and upward direction, and the magnitude of the thrust is positively correlated with the rotating speed; third axial force: the axial component of the gravity of the rotor and the wheel has a downward direction, and the size of the axial component is changed along with the posture adjustment of the blood pump; fourth axial force: the magnetic suspension bearing generates axial thrust to the rotor and the impeller, the direction of the axial thrust is upward or downward, and the size and the direction of the axial thrust can be changed along with the position of the magnetic suspension magnetic group; fifth axial force: the ceramic bearing axially supports force, the direction is upward, and the force disappears after the impeller is suspended; sixth axial force: the axial thrust of the hydraulic pressure generated in the upper wedge-shaped groove 8 is in the axial downward direction; seventh axial force: the axial thrust of the hydraulic pressure generated in the lower wedge-shaped groove 9 is in the axial direction upward; the sixth axial force and the seventh axial force are positively correlated with the magnitude of the force and the rotating speed, positively correlated with the wedge-shaped included angle, negatively correlated with the magnitude of the wedge-shaped space and in exponential relation. The first to fifth axial forces are passive forces and are called weak influence forces; the sixth axial force and the seventh axial force are main forces and are called strong influence forces, the two forces are automatically kept balanced under the condition of overcoming the first axial force to the fifth axial force, and the axial suspension of the rotor and the impeller is ensured only when the sum of the axial force vectors is kept zero.

The above expressions downward or upward are with reference to the direction of the presentation as shown in the drawing, and with reference to the drawing, the radial forces are in the horizontal direction.

As mentioned above, the radial suspension and the axial suspension can make the rotor and the impeller fully suspended, thereby realizing the smooth running and the work of the blood pump.

The technical effects that can be achieved by the embodiments of the present description are as follows:

the patent is based on a patent technology, namely a position-controlled magnetic suspension centrifugal blood pump (publication No. CN 112473000A), and the technical improvement is carried out, a magnetic suspension bearing is arranged at the middle section of the blood pump, because an impeller is a part bearing load, the magnetic suspension bearing can ensure that the radial suspension effect is better, the gravity center of a rotor and the impeller is more stable, and the vibration or vibration amplitude is smaller; the impeller is also technically optimized, and the bidirectional hydraulic pressure can be generated, so that the axial suspension effect of the impeller is better; the axial suspension and the radial suspension are combined, the suspension freedom degree of the rotor and the impeller is higher, and the blood pump works more stably.

Compared with the existing mechanical bearing blood pump, the blood pump disclosed by the embodiment of the specification has the advantages that in the suspension state when the blood pump works normally, the bearings have no friction, the hemolysis can be reduced, the service life of the blood pump is prolonged, and the thrombosis complications triggered by friction heating can be reduced.

Compared with the existing magnetic suspension blood pump, the suspension bearing in the embodiment of the specification is a permanent magnet bearing, belongs to passive magnetic suspension, does not need a complex detection, feedback and control system, has a simpler structure and stable performance, and can greatly improve the technical reliability and the use safety of the blood pump; the volume and the weight of the blood pump are smaller, so that the operation invasion of the blood pump can be reduced, and the practicability is improved; the internal structure of the full-suspension blood pump is simple and smooth, has no dead space or dead angle, and can effectively prevent thrombosis.

In the description herein, references to the description of the term "one embodiment," "some embodiments," "an example," "a specific example," or "some examples," etc., mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, the schematic representations of the terms used above do not necessarily refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

Although embodiments of the present invention have been shown and described, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention, and that variations, modifications, substitutions and alterations of the above embodiments may be made by those of ordinary skill in the art without departing from the scope of the present invention.

Claims (10)

1. A magnetic-liquid double-suspension centrifugal blood pump comprises a pump shell, a servo motor (2), a rotor (3), an impeller (4), a magnetic suspension bearing (6) and a support bearing (7),

the pump shell comprises an inlet pipeline (1) positioned above, and a pump cavity upper cover (501) and a pump cavity lower cover (503) positioned below;

the inlet pipeline (1) is formed by sequentially sleeving an outer pipe (101), a middle pipe (102) and an inner pipe (103), a pump inlet (105) is formed in the upper end of the inlet pipeline (1) and communicated with the inner pipe (103), the lower end of the inlet pipeline (1) is hermetically connected with a pump cavity upper cover (501), the pump cavity upper cover (501) is hermetically connected with a pump cavity lower cover (503), a pump cavity (5) is formed in the pump cavity upper cover (503) and communicated with a cavity of the inner pipe (103), and a pump outlet (506) is formed in the pump cavity lower cover (503) and communicated with the pump cavity (5);

the rotor (3) is correspondingly arranged in the inner pipe (103), an integrated impeller (4) is arranged below the rotor (3), and the impeller (4) is arranged in a pump cavity (5) formed by sealing the pump cavity upper cover (501) and the pump cavity lower cover (503);

the servo motor (2) comprises rotor magnetic steel (201) arranged in the rotor (3) and a stator assembly arranged between a middle pipe (102) and an inner pipe (103) of the inlet pipeline (1), and the stator assembly drives the rotor (3) and the impeller (4) to respectively rotate in the inner pipe and the pump cavity to do work when being electrified;

the method is characterized in that:

the magnetic suspension bearing (6) comprises an inner magnetic core group (602) and an outer magnetic ring group (601) which are respectively composed of the same number of annular magnetic sheets, the inner magnetic core group (602) is arranged in the lower end of the rotor (3), and the outer magnetic ring group is arranged between a middle pipe (102) and an inner pipe (103) at the lower end of the inlet pipeline (1);

the support bearing (7) comprises a ceramic ball (701) and a ceramic pad (702), the ceramic ball (701) is arranged at the bottom of the rotor (3), the middle of the pump cavity lower cover (503) corresponds to the bottom of the rotor (3) and is upwards provided with a boss (505), and the ceramic pad (702) is arranged on the boss (505).

2. The magnetic-fluid double-suspension centrifugal blood pump of claim 1, wherein: the magnetic shielding device is characterized by further comprising a magnetic shielding group (10), wherein the magnetic shielding group (10) comprises a shielding ring (1001) which is arranged in the rotor (3) and positioned above the inner magnetic core group (602), and an outer shielding ring (1002) which is arranged between the middle pipe (102) and the inner pipe (103) of the inlet pipeline (1) and positioned above the outer magnetic ring group (601).

3. The magnetic-fluid double-suspension centrifugal blood pump of claim 1, wherein: and the upper end parts of the inner pipe and the outer pipe of the inlet pipeline (1) are provided with brackets (104).

4. The magnetic-fluid double-suspension centrifugal blood pump of claim 1, wherein: the stator assembly comprises a stator winding (202), a stator core (203) and a cable (204) arranged between an inner pipe and an outer pipe of the inlet pipeline (1).

5. The magnetic-fluid double-suspension centrifugal blood pump of claim 4, wherein: the rotor (3) comprises a rotor shell (301) arranged outside the rotor magnetic steel (201).

6. The magnetic-fluid double-suspension centrifugal blood pump of claim 1, wherein: the number of the impellers is four, and the impellers are uniformly arranged below the rotor.

7. The magnetic-fluid double-suspension centrifugal blood pump of claim 1, wherein: the upper side surface and the lower side surface of the blade of the impeller are respectively provided with an upper inclined surface (402) and a lower inclined surface (403), and an upper wedge-shaped hydraulic pressure groove (8) and a lower wedge-shaped hydraulic pressure groove (9) are respectively formed between the upper inclined surface (402) and the lower inclined surface (403) and the pump cavity.

8. The magnetic-fluid double-suspension centrifugal blood pump of claim 7, wherein: the inclination angle of the upper inclined surface and the lower inclined surface is 3-10 degrees.

9. The magnetic-fluid double-suspension centrifugal blood pump of claim 1, wherein: the inner magnetic core group (602) and the outer magnetic ring group (601) are respectively bonded together by two or three or four annular magnetic sheets which are in like magnetic repulsion.

10. The magnetic-fluid double-suspension centrifugal blood pump of claim 1, wherein: the outer side surface of the lower end of the outer pipe of the inlet pipeline (1) is provided with a sewing ring (11).

Images