Centrifugal blood pump with magnetic levitation bearing and method of operation

Abstract

The application discloses a centrifugal blood pump adopting a magnetic suspension bearing and a working method, and solves the problem of a large volume of a blood pump in the prior art, has the beneficial effects of reducing the volume of the blood pump and avoiding thrombosis, and specifically has the following technical scheme: a centrifugal blood pump adopting a magnetic suspension bearing, comprising a mounting seat, the mounting seat being provided with a first recess, an electromagnetic coil being arranged on the peripheral side of the first recess of the mounting seat, and a driving coil being arranged on the inner side of the first recess of the mounting seat; a volute is provided with a second recess, and a first permanent magnetic ring is arranged on one side of the first recess of the volute; a pump cover is detachably connected with the volute and covers the second recess of the volute; a rotor is arranged at the second recess of the volute, and the rotor comprises a rotor body, an impeller structure being arranged on the side of the rotor body close to the pump cover, the rotor body being provided with a second permanent magnetic ring and a third permanent magnetic ring, a suspension coil generating a suspension force on the second permanent magnetic ring, the rotor being actively radially suspended, and the driving coil generating a driving force on the second permanent magnetic ring.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of centrifugal blood pumps, in particular to a centrifugal blood pump adopting magnetic suspension bearing and working method. BACKGROUND

[0002] The statements in this section merely provide background information related to the present application and do not necessarily constitute the prior art.

[0003] In recent years, the research and clinical application of blood pumps at home and abroad have developed rapidly. Many blood pumps applied in clinical practice adopt the third generation of non-contact suspension bearing. The suspension bearing effectively avoids the problems of heating and thrombosis caused by contact wear of mechanical bearings, so it is a hot spot in modern blood pump research.

[0004] According to the different principles of realizing suspension, the suspension bearing is divided into three ways: magnetic suspension type, hydraulic suspension type and magnetic liquid coupling type (hybrid) suspension bearing. Among them, the magnetic suspension bearing realizes the suspension of the rotor by the electromagnetic force generated by the energization of the electromagnetic coil. According to Earnshaw's theory, only permanent magnets cannot realize stable passive suspension. In order to maintain the stability of the system, at least one direction of movement needs to be actively controlled. Therefore, the existing magnetic suspension type blood pump has a set of active control system, including sensors, controllers, electromagnets, etc. (for example, US patent US7470246). The inventor found that this inevitably brings a series of problems such as large size and high energy consumption, which to a large extent restricts the development of magnetic suspension type blood pump; the hydraulic suspension bearing realizes the passive suspension of the rotor by using the dynamic pressure generated by the moving fluid in the wedge-shaped gap. Compared with the magnetic suspension bearing, it has simple structure, no active control and small energy consumption, but the thrombosis problem caused by small suspension gap cannot be ignored; the magnetic liquid coupling type suspension bearing couples the magnetic suspension and the hydraulic suspension bearing together to realize the suspension support of the impeller. SUMMARY

[0005] In view of the deficiencies of the prior art, the purpose of the present application is to provide a centrifugal blood pump adopting magnetic suspension bearing, which reduces the size and weight of the magnetic suspension type blood pump, avoids excessive energy consumption, and improves the safety and stability of the blood pump.

[0006] In order to achieve the above purpose, the present application is realized by the following technical scheme:

[0007] A centrifugal blood pump adopting magnetic suspension bearing, comprising:

[0008] The mounting seat has a first recess, and the mounting seat is provided with a driving coil and a suspension coil on the circumferential side of the first recess, and the mounting seat is provided with a first permanent magnetic ring on the inner side of the suspension coil;

[0009] The volute is provided with a second recess, the volute is provided with a blood outlet communicated with the recess, one side of the volute is inserted into the first recess of the mounting seat, and the volute is provided with a first permanent magnetic ring at one side in the first recess;

[0010] The pump cover is detachably connected with the volute and covers the second recess of the volute, and the pump cover is provided with a blood inlet communicated with the second recess;

[0011] The rotor is located at the second recess of the volute, the rotor comprises a rotor body, the rotor body is provided with an impeller structure at one side close to the pump cover, the rotor body is provided with a second permanent magnetic ring and a third permanent magnetic ring, a suspension coil generates a suspension force (Maxwell force) on the second permanent magnetic ring to realize active radial suspension of the rotor, a driving coil generates a driving force (Lorentz force) on the second permanent magnetic ring to rotate the rotor, the third permanent magnetic ring is in position correspondence with the first permanent magnetic ring to generate a repulsion force to realize passive suspension of the rotor, and the directions of the driving force and the repulsion force are perpendicular to each other.

[0012] The centrifugal blood pump with the magnetic suspension bearing as described above, the rotor further comprises a rotor cover plate, the rotor cover plate is located at one side of the impeller structure away from the rotor body, the rotor cover plate is connected with the rotor body, and a plurality of first spiral grooves with a radius range centered on the rotor cover plate are arranged on one side of the rotor cover plate away from the impeller structure.

[0013] The rotor cover plate has a set distance from the inner surface of the pump cover, which is beneficial to improve the initial speed of blood falling on the rotor cover plate.

[0014] The centrifugal blood pump with the magnetic suspension bearing as described above, from the center of the rotor cover plate outward, the width of the first spiral groove is narrow inside and wide outside, which is beneficial to increase the flowability of blood.

[0015] Further, the ratio a2 / a1 of the groove ridge and the groove width of the first spiral groove is 0.8-1.3.

[0016] The centrifugal blood pump with the magnetic suspension bearing as described above, the surface of the rotor body away from the impeller structure is provided with a second spiral groove.

[0017] From the center of the rotor body outward, the width of the second spiral groove is wide inside and narrow outside, which provides greater hydraulic support and makes the rotor more stable when suspended.

[0018] In the second spiral groove, the ratio b1 / b2 of the width of the second spiral groove at the inner diameter and the width of the second spiral groove at the outer diameter is 1.90-2.30.

[0019] The centrifugal blood pump with magnetic suspension bearing as described above, wherein the second recess has a step inside, so that the second recess comprises a first section and a second section, the inner diameter of the first section is larger than that of the second section, and the blood outlet is located at the side wall of the first section of the second recess of the volute.

[0020] The centrifugal blood pump with magnetic suspension bearing as described above, wherein the height of the third permanent magnetic ring is smaller than that of the second permanent magnetic ring, the width of the second permanent magnetic ring is smaller than that of the third permanent magnetic ring, and the third permanent magnetic ring is flat;

[0021] The magnetization ranges of the first permanent magnetic ring and the third permanent magnetic ring correspond to each other.

[0022] The centrifugal blood pump with magnetic suspension bearing as described above, wherein the outer diameter of the third permanent magnetic ring is smaller than the inner diameter of the second permanent magnetic ring.

[0023] The mounting seat is provided with a magnetic coupler on the circumferential side of the first recess, the magnetic coupler is connected with the driving coil, the third permanent magnetic ring is embedded in the side surface of the rotor body close to the magnetic coupler, and the second permanent magnetic ring is embedded in the circumferential direction of the rotor body.

[0024] The centrifugal blood pump with magnetic suspension bearing as described above, wherein the impeller structure comprises a plurality of first blades and a plurality of second blades, the first blades and the second blades are alternately fixed to the rotor body, and the first blades and the second blades are alternately arranged, which is beneficial to increase the lift of the centrifugal blood pump, avoid flow displacement at the inlet of the blades, and prevent the generation of secondary flow in the impeller; the rotor cover plate is connected with the rotor body through a support, and the first blades and the second blades are arranged in a spiral shape around the support.

[0025] The length of the first blade is greater than that of the second blade.

[0026] The centrifugal blood pump with magnetic suspension bearing as described above, wherein the inlet angle of the first blade and the second blade ranges from 20° to 35°.

[0027] The outlet angle of the first blade and the second blade ranges from 35° to 45°.

[0028] The wrap angle of the first blade and the second blade ranges from 60° to 80°.

[0029] In a second aspect, the application further provides a working method of the centrifugal blood pump with magnetic suspension bearing, which comprises the following contents.

[0030] The second permanent magnetic ring generates suspension force with the suspension coil, so as to realize active radial suspension of the rotor; the third permanent magnetic ring generates repulsion force with the first permanent magnetic ring, so as to realize passive axial suspension of the rotor; and the second permanent magnetic ring generates driving force with the driving coil, so as to drive the rotor to rotate.

[0031] After the blood enters the pump cover through the blood inlet, the blood enters the second recess;

[0032] The centrifugal force of the rotation of the rotor makes part of the blood flow to the blood outlet after passing through the impeller structure, and part of the blood flow to the blood outlet after passing through the rotor and the volute gap.

[0033] The beneficial effects of the present application are as follows:

[0034] 1) The present application provides a centrifugal blood pump, which comprises a pair of permanent magnetic rings, a second permanent magnetic ring and a driving coil, and the rotor is suspended relative to the volute, the second permanent magnetic ring generates a suspension force with the suspension coil, the rotor is actively suspended in the radial direction, the second permanent magnetic ring generates a driving force with the driving coil, the driving coil generates a magnetic field, the second permanent magnetic ring cuts the magnetic induction lines to ensure the continuous rotation of the rotor, and the blood flow path is ensured, and the space between the rotor and the volute can support the rotor to form a hydrodynamic bearing, so that the blood pump has a smaller volume and weight, energy is effectively saved, and the hydrodynamic suspension of the blood pump is increased, so that the rotor is more stable when suspended.

[0035] 2) The present application provides a centrifugal blood pump, which comprises a pair of permanent magnetic rings, a second permanent magnetic ring and a driving coil, and the rotor is suspended relative to the volute, the second permanent magnetic ring generates a suspension force with the suspension coil, the rotor is actively suspended in the radial direction, the second permanent magnetic ring generates a driving force with the driving coil, the driving coil generates a magnetic field, the second permanent magnetic ring cuts the magnetic induction lines to ensure the continuous rotation of the rotor, and the blood flow path is ensured, and the space between the rotor and the volute can support the rotor to form a hydrodynamic bearing, so that the blood pump has a smaller volume and weight, energy is effectively saved, and the hydrodynamic suspension of the blood pump is increased, so that the rotor is more stable when suspended.

[0036] 3) The present application provides a centrifugal blood pump, which comprises a pair of permanent magnetic rings, a second permanent magnetic ring and a driving coil, and the rotor is suspended relative to the volute, the second permanent magnetic ring generates a suspension force with the suspension coil, the rotor is actively suspended in the radial direction, the second permanent magnetic ring generates a driving force with the driving coil, the driving coil generates a magnetic field, the second permanent magnetic ring cuts the magnetic induction lines to ensure the continuous rotation of the rotor, and the blood flow path is ensured, and the space between the rotor and the volute can support the rotor to form a hydrodynamic bearing, so that the blood pump has a smaller volume and weight, energy is effectively saved, and the hydrodynamic suspension of the blood pump is increased, so that the rotor is more stable when suspended.

[0037] 4) The present application provides a centrifugal blood pump, which comprises a pair of permanent magnetic rings, a second permanent magnetic ring and a driving coil, and the rotor is suspended relative to the volute, the second permanent magnetic ring generates a suspension force with the suspension coil, the rotor is actively suspended in the radial direction, the second permanent magnetic ring generates a driving force with the driving coil, the driving coil generates a magnetic field, the second permanent magnetic ring cuts the magnetic induction lines to ensure the continuous rotation of the rotor, and the blood flow path is ensured, and the space between the rotor and the volute can support the rotor to form a hydrodynamic bearing, so that the blood pump has a smaller volume and weight, energy is effectively saved, and the hydrodynamic suspension of the blood pump is increased, so that the rotor is more stable when suspended.

[0038] 5) The present application provides a centrifugal blood pump, which comprises a pair of permanent magnetic rings, a second permanent magnetic ring and a driving coil, and the rotor is suspended relative to the volute, the second permanent magnetic ring generates a suspension force with the suspension coil, the rotor is actively suspended in the radial direction, the second permanent magnetic ring generates a driving force with the driving coil, the driving coil generates a magnetic field, the second permanent magnetic ring cuts the magnetic induction lines to ensure the continuous rotation of the rotor, and the blood flow path is ensured, and the space between the rotor and the volute can support the rotor to form a hydrodynamic bearing, so that the blood pump has a smaller volume and weight, energy is effectively saved, and the hydrodynamic suspension of the blood pump is increased, so that the rotor is more stable when suspended.

[0039] 6) The present application provides a centrifugal blood pump, which comprises a pair of permanent magnetic rings, a second permanent magnetic ring and a driving coil, and the rotor is suspended relative to the volute, the second permanent magnetic ring generates a suspension force with the suspension coil, the rotor is actively suspended in the radial direction, the second permanent magnetic ring generates a driving force with the driving coil, the driving coil generates a magnetic field, the second permanent magnetic ring cuts the magnetic induction lines to ensure the continuous rotation of the rotor, and the blood flow path is ensured, and the space between the rotor and the volute can support the rotor to form a hydrodynamic bearing, so that the blood pump has a smaller volume and weight, energy is effectively saved, and the hydrodynamic suspension of the blood pump is increased, so that the rotor is more stable when suspended. BRIEF DESCRIPTION OF DRAWINGS

[0040] The accompanying drawings, which form a part of this specification, are included to provide a further understanding of the application, and are incorporated into and constitute a part of this specification. The embodiments of the application, and their

[0041] Figure 1 is a schematic diagram of the structure principle of a centrifugal blood pump with magnetic levitation bearing according to one or more embodiments of the present application.

[0042] Figure 2 is a schematic diagram of the structure of the lower volute of a centrifugal blood pump with magnetic levitation bearing according to one or more embodiments of the present application.

[0043] Figure 3 is a sectional view of the rotor of a centrifugal blood pump with magnetic levitation bearing according to one or more embodiments of the present application.

[0044] Figure 4 is a schematic diagram of the parameters of the impeller structure of a centrifugal blood pump with magnetic levitation bearing according to one or more embodiments of the present application.

[0045] Figure 5 is a schematic diagram of the first helical groove on the surface of the rotor cover plate of a centrifugal blood pump with magnetic levitation bearing according to one or more embodiments of the present application.

[0046] Figure 6(a) is a schematic diagram of the second helical groove on the surface of the rotor body of a centrifugal blood pump with magnetic levitation bearing according to one or more embodiments of the present application.

[0047] Figure 6(b) is an enlarged view of B in Figure 6(a) of the present application.

[0048] Figure 6(c) is an enlarged view of A in Figure 6(a) of the present application.

[0049] Figure 7 is a schematic diagram of the principle of the main flow channel of a centrifugal blood pump with magnetic levitation bearing according to one or more embodiments of the present application.

[0050] Figure 8 is a schematic diagram of the principle of the flow channel at the impeller structure of a centrifugal blood pump with magnetic levitation bearing according to one or more embodiments of the present application.

[0051] Figure 9 is a schematic diagram of the levitation sectional principle of a centrifugal blood pump with magnetic levitation bearing according to one or more embodiments of the present application.

[0052] In the drawings: the mutual distances or dimensions are exaggerated for showing the positions of the parts, and the schematic diagrams are only for illustration.

[0053] Wherein: 1-pump cover, 2-volute, 3-rotor, 4-mounting base, 3A-rotor cover plate, 3B-first blade, 3C-second blade, 3D-rotor body, 3E-second spiral groove, 3F-first spiral groove, 3G-second permanent magnetic ring, 3H-third permanent magnetic ring, 4A-magnetic coupling, 4B-driving coil, 4C-suspension coil, 4D-first permanent magnetic ring. DETAILED DESCRIPTION

[0054] It should be noted that the following detailed description is illustrative only, and is intended to provide further description of the application. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs.

[0055] It is to be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of example embodiments in accordance with the present application. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises" and / or "comprising," when used in this specification, specify the presence of stated features, steps, operations, elements, and / or components, but do not preclude the presence or addition of one or more other features, steps, operations, elements, components, and / or groups thereof.

[0056] For the convenience of description, if "upper", "lower", "left", "right" appear in the present application, it only means consistent with the upper, lower, left, right direction of the drawing itself, and does not limit the structure, only for the convenience of describing the present application and simplifying the description, and does not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application.

[0057] The terms "mounting", "connected", "connection", "fixed", and the like in the present application should be understood in a broad sense, for example, can be fixed connection, can also be detachable connection, or integral; can be mechanical connection, can also be electrical connection, can be direct connection, can also be indirect connection through an intermediate medium, can be internal connection of two elements, or interaction relationship between two elements, and those skilled in the art can understand the specific meaning of the above terms in the present application according to the specific circumstances.

[0058] As introduced in the background, there is a problem of large volume of blood pump in the prior art, in order to solve the above technical problem, the present application proposes a centrifugal blood pump adopting magnetic suspension bearing.

[0059] Example one

[0060] In a typical embodiment of the present application, reference is made to Figure 1 , Figure 2 and Figure 9As shown, a centrifugal blood pump with magnetic suspension bearing comprises:

[0061] The mounting seat 4 has a first recess, the mounting seat 4 is provided with a magnetic coupling 4A on the circumferential side of the first recess, the mounting seat 4 is provided with a driving coil 4B and a suspension coil 4C, the suspension coil and the driving coil are arranged in an upper and lower manner, and the driving coil is connected with the magnetic coupling 4A;

[0062] The volute 2 is provided with a second recess, the volute 2 is provided with a blood outlet communicated with the recess, one side of the volute 2 is inserted into the first recess of the mounting seat 4, and the volute 2 is provided with a first permanent magnetic ring on one side of the first recess;

[0063] The pump cover 1 is detachably connected with the volute 2 and covers the second recess of the volute, and the pump cover is provided with a blood inlet communicated with the second recess;

[0064] The rotor 3 is located at the second recess of the volute 2, the rotor 3 comprises a rotor body 3D, the rotor body is provided with an impeller structure on the side close to the pump cover, the rotor body is provided with a second permanent magnetic ring and a third permanent magnetic ring, the suspension coil generates a suspension force on the second permanent magnetic ring to realize active radial suspension of the rotor, the driving coil generates a driving force on the second permanent magnetic ring to make the rotor rotate, the third permanent magnetic ring corresponds to the position of the first permanent magnetic ring to generate a repulsive force to realize passive suspension of the rotor, and the directions of the driving force and the repulsive force are perpendicular to each other.

[0065] The pump cover 1 has a set height, the pump cover 1 is T-shaped, the pump cover 1 is provided with a blood inlet channel, the blood inlet channel is communicated with the second recess, the top of the blood inlet channel is the blood inlet, and the pump cover is fastened with the second recess of the volute through fasteners such as bolts.

[0066] The mounting seat 4 has a set height, the magnetic coupling 4A is located on the circumferential side of the first recess, the first permanent magnetic ring 4D is located below the first recess, the magnetic coupling 4A adopts an existing magnetic coupling, the magnetic coupling 4A has an iron core, the suspension coil is wound on the two sides of the iron core, the driving coil is wound on the side away from the first recess, the suspension coil 4C is located above the driving coil 4B, the suspension coil is located on the circumferential side of the first permanent magnetic ring 4D, and the suspension coil has a set distance from the first permanent magnetic ring, the iron core between the magnetic coupling and the driving coil passes through the suspension coil, and the magnetic coupling adjusts the size of the driving force by changing the distance between the magnetic coupling and the second permanent magnetic ring.

[0067] The rotor 3 further comprises a rotor cover plate 3A, the rotor cover plate 3A has a set height, the rotor cover plate is located on the side away from the rotor body of the impeller structure, the rotor cover plate 3A is connected with the rotor body 3D, and the rotor cover plate 3A is provided with a plurality of first spiral grooves with a set radius range and taking the rotor cover plate as the center on the side away from the impeller structure.

[0068] Understandably, there is a set distance between the rotor cover 3A and the inner surface of the pump cover 1, so that after the blood enters from the blood inlet of the pump cover, it enters the blood channel of the pump cover and then falls to the surface of the rotor cover, which helps to increase the initial velocity of the blood falling to the rotor cover.

[0069] refer to Figure 3 As shown, the rotor includes a rotor cover plate, the rotor height is h, which ranges from 15 to 24 mm, and the depth of the first helical groove is h0, which ranges from 0.06 to 0.12 mm.

[0070] refer to Figure 5 As shown, r i Let θ be the radius vector. i α1 is the polar angle, α2 is the helix angle, and r1 is the polar angle θ. i When the radial direction is zero, from the center of the rotor cover plate 3A outwards, the width of the first spiral groove 3F is narrower inside and wider outside, which is beneficial to increase the flow of blood; in this embodiment, the ratio of the groove ridge to the groove width of the first spiral groove 3F, a2 / a1, is 0.8-1.3.

[0071] In addition, a second helical groove 3E is provided on the surface of the rotor body 3D away from the impeller structure; from the center of the rotor body outward, the width of the second helical groove 3E is wider at the inside and narrower at the outside, providing greater hydraulic support and making the rotor more stable when suspended.

[0072] Referring to Figures 6(a), 6(b) and 6(c), in the second spiral groove 3E, the ratio of the width of the second spiral groove at the inner diameter to the width of the second spiral groove at the outer diameter, b1 / b2, is 1.90-2.30.

[0073] Understandably, both the first spiral groove 3F and the second spiral groove 3E are composed of two logarithmic spirals, with the spiral angle α of the logarithmic spirals ranging from 10 to 30° and the spiral groove depth h0 ranging from 0.06 to 0.12 mm.

[0074] In this embodiment, the second recess has a step inside, so that the second recess includes a first section and a second section. The inner diameter of the first section is larger than the inner diameter of the second section. The blood outlet is located on the side wall of the first section of the second recess of the volute. The blood outlet is aligned with the lower half of the rotor cover plate 3A and the upper half of the impeller structure. The volute has an outlet pipe with an outlet channel. The blood outlet is located at the inlet end of the outlet channel.

[0075] The height of the third permanent magnet ring 3H is less than the height of the second permanent magnet ring 3G, and the width of the second permanent magnet ring is less than the width of the third permanent magnet ring.

[0076] It is easy to understand that after the rotor enters the second recess, the second permanent magnet ring 3G is located on the inner side of the magnetic coupling 4A, there is a set distance between the second permanent magnet ring and the suspension coil, the suspension force is generated between the suspension coil and the second permanent magnet ring, the first permanent magnet ring 4D and the third permanent magnet ring 3H are parallel to each other, and the magnetization ranges of the first permanent magnet ring and the third permanent magnet ring correspond one by one.

[0077] The outer diameter of the third permanent magnet ring 3H is smaller than the inner diameter of the second permanent magnet ring 3G; the third permanent magnet ring is embedded in the side surface of the rotor body close to the first permanent magnet ring 4D, and the second permanent magnet ring is embedded in the circumferential direction of the rotor body, so as to ensure that the rotor is radially suspended, and the third permanent magnet ring is located at the end side of the rotor, thereby ensuring that the rotor is axially suspended.

[0078] It can be understood that the driving coil, the suspension coil and the magnetic coupling are all prior art.

[0079] Regarding the impeller structure, the impeller structure includes a plurality of first blades 3B and a plurality of second blades 3C, the first blades 3B and the second blades 3C are fixed alternately to the rotor body, and the first blades and the second blades are arranged alternately, which is beneficial to increase the lift of the centrifugal blood pump, avoid flow exclusion at the inlet of the blades, and prevent the generation of secondary flow in the impeller; the rotor cover plate 3A is connected to the rotor body 3D through a support, the first blades 3B and the second blades 3C are arranged in a spiral shape around the support, and the support can be a hollow support; the length of the first blades is greater than the length of the second blades.

[0080] In this embodiment, the first blades 3B are uniformly distributed, and the number is 4-8; the second blades 3C are uniformly distributed, and the number is 4-8.

[0081] The first blades 3B and the second blades 3C each have a height, and in some examples, the height of the first blades and the second blades gradually decreases from the center of the rotor to the outer side of the rotor, which is beneficial to guide blood from the side of the impeller structure into the side gap between the rotor body and the volute.

[0082] In this embodiment, the support forms a circular ring, which defines the inner diameter d of the rotor body, and the value is 10-15 mm, and D is the outer diameter of the rotor body, and the value is 30-40 mm.

[0083] Reference Figure 4 As shown, the inlet angle β1 of the first blades 3B and the second blades 3C is in the range of 20°-35°; the outlet angle β2 of the first blades and the second blades is in the range of 35°-45°; the wrap angle δ of the first blades and the second blades is in the range of 60°-80°, and w is the width of the large impeller 3B and the small impeller 3C, and the value is 0.5-1.5 mm.

[0084] It can be understood that the diameter of the rotor cover plate 3A is smaller than the maximum outer diameter of the impeller structure, the maximum outer diameter of the impeller structure is greater than the outer diameter of the rotor body, the main body of the rotor body is located in the second section of the second recess of the volute, and the impeller structure and the rotor cover plate are located at the first section of the second recess.

[0085] The centrifugal blood pump provided by the embodiment can generate a rotating magnetic field after the driving coil is electrified, drive the second permanent magnetic ring in the rotor to rotate, drive the large impeller and the small impeller to rotate, make blood flow out of the outlet of the volute, assist the heart to complete blood circulation, the first spiral groove on the surface of the rotor cover plate can increase the flow of blood, the spiral groove on the side of the rotor body away from the impeller structure can increase the hydrodynamic support, the first spiral groove with the narrow inside and the wide outside in the rotor cover plate is provided with multiple sections, the efficiency of the blood pump can be improved, the hydraulic loss can be reduced, the blood flow can be increased, and thus the formation of thrombus can be avoided; the second spiral groove with the wide inside and the narrow outside in the rotor body can provide greater hydrodynamic support, and the rotor can be more stable when suspended.

[0086] Embodiment two

[0087] The embodiment provides a working method of the centrifugal blood pump with the magnetic suspension bearing in embodiment one, and the working method comprises the following contents. Figure 8 and Figure 9 As shown in the drawings, the working method comprises the following contents.

[0088] The volute is connected with the mounting seat, the second permanent magnetic ring and the suspension coil generate a suspension force, the rotor is actively radially suspended, the third permanent magnetic ring and the first permanent magnetic ring interact to generate repulsive forces F1 and F2, and the rotor is axially passively suspended; the driving coil is electrified to generate a rotating magnetic field, the second permanent magnetic ring is driven to cut a magnetic induction line to generate a driving force to drive the rotor to rotate, and the rotor rotates clockwise.

[0089] After the blood enters the pump cover through the blood inlet, the blood enters the second recess, falls to the surface of the rotor cover plate, and is distributed to the circumferential side of the rotor cover plate along the first spiral groove on the surface of the rotor cover plate.

[0090] The centrifugal force of the rotating rotor makes most of the blood flow through the first blade and the second blade to reach the blood outlet, and a small part of the blood flows through the space between the impeller structure and the side wall of the second recess to reach the blood outlet by combining with the main blood flow through the rotor and the volute side gap, when the blood flows through the second spiral groove, the second spiral groove is beneficial to increasing the blood flow between the rotor and the volute, and simultaneously provides passive support force to the rotor, and when part or all of the permanent magnetic rings fail, the rotor still realizes suspension relative to the volute.

[0091] The above only describes the preferred embodiments of the present application and is not used to limit the present application. For those skilled in the art, the present application can have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A centrifugal blood pump employing magnetic levitation bearings, characterized in that, The application relates to a blood pump, comprising: a mounting seat, which is provided with a first recess, a driving coil and a suspension coil on the periphery of the first recess, and a first permanent magnetic ring on the inner side of the suspension coil; a volute, which is provided with a second recess, a blood outlet communicated with the recess, and the first permanent magnetic ring on one side of the first recess; a pump cover, which is detachably connected with the volute, covers the second recess of the volute, and is provided with a blood inlet communicated with the second recess; a rotor, which is located at the second recess of the volute, comprises a rotor body, is provided with an impeller structure on the side close to the pump cover, is provided with a second permanent magnetic ring and a third permanent magnetic ring, and is suspended by the suspension coil to realize active radial suspension of the rotor, and is driven by the driving coil to rotate, wherein the third permanent magnetic ring is correspondingly arranged with the first permanent magnetic ring to generate repulsion force and realize passive suspension of the rotor, and the driving force and the repulsion force are perpendicular to each other; the height of the third permanent magnetic ring is smaller than that of the second permanent magnetic ring, and the width of the second permanent magnetic ring is smaller than that of the third permanent magnetic ring; the magnetization ranges of the first permanent magnetic ring and the third permanent magnetic ring are one-to-one corresponding; the outer diameter of the third permanent magnetic ring is smaller than the inner diameter of the second permanent magnetic ring; the rotor further comprises a rotor cover plate, which is provided with a plurality of first spiral grooves with a radius range centered on the rotor cover plate on the side away from the impeller structure; the rotor cover plate is located on the side of the impeller structure away from the rotor body and is connected with the rotor body; from the center of the rotor cover plate to the outside, the width of the first spiral groove is narrow in the inside and wide in the outside; the surface of the rotor body away from the impeller structure is provided with a second spiral groove; from the center of the rotor body to the outside, the width of the second spiral groove is wide in the inside and narrow in the outside; the first spiral groove and the second spiral groove are both composed of two logarithmic spiral lines.

2. A centrifugal blood pump employing magnetic levitation bearings according to claim 1, characterized in that the rotor cover plate and the inner surface of the pump cover have a set distance.

3. A centrifugal blood pump employing magnetic levitation bearings according to claim 2, characterized in that Further, the ratio of the land width to the land width of the first spiral groove is 0.8-1.3 a 2 / a 1is 0.8-1.

3.

4. A centrifugal blood pump employing magnetic levitation bearings according to claim 1, characterized in that In the second spiral groove, the ratio of the width of the second spiral groove at the inner diameter to the width of the second spiral groove at the outer diameter is b 1 / b 2is 1.90-2.

30.

5. A centrifugal blood pump employing magnetic levitation bearings according to claim 1, characterized in that, the second recess has a step inside, so that the second recess comprises a first section and a second section, the inner diameter of the first section is larger than that of the second section, and the blood outlet is located at the side wall of the first section of the second recess of the volute.

6. A centrifugal blood pump employing magnetic levitation bearings according to claim 1, characterized in that the mounting seat is provided with a magnetic coupler on the periphery of the first recess, the magnetic coupler is connected with the driving coil, the third permanent magnetic ring is embedded in the side of the rotor body close to the magnetic coupler, and the second permanent magnetic ring is embedded in the circumferential direction of the rotor body.

7. A centrifugal blood pump employing magnetic levitation bearings according to claim 2, characterized in that the impeller structure comprises a plurality of first blades and a plurality of second blades, the first blades and the second blades are alternately fixed to the rotor body, the rotor cover plate is connected with the rotor body through a support, and the first blades and the second blades are arranged in a spiral shape around the support; the length of the first blades is larger than that of the second blades.

8. A centrifugal blood pump employing magnetic levitation bearings according to claim 7, characterized in that the inlet angle of the first blades and the second blades ranges from 20 DEG to 35 DEG; the outlet angle of the first blades and the second blades ranges from 35 DEG to 45 DEG; the wrap angle of the first blades and the second blades ranges from 60 DEG to 80 DEG.

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