Magnetic suspension type centrifugal pump

Abstract

According to the magnetic suspension type centrifugal pump, rotation driving and axial position control of a rotor are completely independent and located on the two sides of a rotor body respectively, and the control logic is simple. Moreover, the full-suspension operation of the rotor can be realized through the magnetic action between the movable magnetic ring and the static magnetic ring, so that no mechanical contact exists between the rotor and the volute (equivalent to a stator); heating and abrasion are reduced, and the possibility of thrombus generation and rolling damage to blood cells is reduced to the maximum extent; and radial suspension limiting of the rotor can be realized by virtue of the movable magnetic ring and the static magnetic ring.

Description

[0001] This application is a divisional application. The application number of the parent application is 202210565543.2, the application date is May 23, 2022, and the name of the invention is “A magnetically levitation centrifugal pump”. Technical Field

[0002] The invention relates to the technical field of vibration reduction, and in particular to a magnetic suspension centrifugal pump. Background Art

[0003] Heart failure (heart failure in English, abbreviated as HF in Chinese), in layman's terms, means that the natural heart cannot pump enough blood to maintain systemic blood circulation. According to statistics from the World Health Organization (WHO), about 15% to 20% of people will suffer from heart failure to varying degrees, and the number of people over 65 years old who are hospitalized due to heart failure accounts for more than 50% of the total number of hospitalizations. At the same time, the mortality rate exceeds 50% after 5 years. For patients with heart failure, there are only three treatment options: conservative drug treatment, heart transplantation, and ventricular assist. The effect of drug treatment is poor, and heart transplantation is very difficult due to donor restrictions. Therefore, ventricular assist device (VAD) has become the most effective treatment for various types of end-stage heart failure recognized worldwide. The main component of the ventricular assist device is a blood pump (Blood Pump in English). Generally, the inflow pipe of the blood pump is connected to the left ventricle or right ventricle of the human heart, and connected to the aorta or pulmonary artery through the outflow pipe. The pump is connected to a control driver (with a power supply device). The control driver controls the blood pump to output blood with a certain pressure (generally in the range of 80-120 mmHg) and flow (generally in the range of 2-10 L / min), sharing the power demand of the human heart for normal human activities.

[0004] In view of the limitations of the use environment of the blood pump, how to make the blood pump have the characteristics of high integration and small size while meeting the functional requirements is a technical issue that technicians in this field have always paid attention to. Summary of the invention

[0005] The object of the present invention is to provide a magnetic suspension centrifugal pump with small volume and compact structure.

[0006] The present invention provides a magnetic suspension centrifugal pump, comprising a volute, a static magnetic ring and a rotor;

[0007] The volute has a suspension cavity, a medium inlet and a medium outlet, the rotor is located inside the suspension cavity, and the static magnetic ring is fixed to the volute.

[0008] The rotor comprises a rotor body, a moving magnetic ring positioned on the rotor body, and at least two blades; the moving magnetic ring is coaxial with the static magnetic ring and is nested to limit the radial position of the rotor body and the volute;

[0009] The rotor body is fixed with a magnetic steel assembly, the magnetic steel assembly includes N first magnetic steels arranged in the circumferential direction, and the magnetic poles of all the first magnetic steels are arranged in a staggered manner; the rotor body is also fixed with a magnetic member, the magnetic member includes at least one of a magnetic ring and an iron core;

[0010] The volute encapsulates a drive coil assembly that is arranged opposite to the magnetic steel assembly, and the drive coil assembly cooperates with the magnetic steel assembly to enable the rotor body to rotate circumferentially; the volute is fixed with a magnetic levitation coil assembly, and when the magnetic levitation coil assembly is energized, the magnetic part and the magnetic levitation coil assembly generate axial force.

[0011] Optionally, a position sensor is further included, for detecting the axial position of the rotor body;

[0012] Alternatively or alternatively, adjacent first magnetic steels are closely fitted together, or the magnetic steel assembly further includes a transverse magnetic conductive steel, the magnetic conductive steel is located between two first magnetic steels, and all the magnetic conductive steels and all the first magnetic steels form a Halbach magnetic steel array.

[0013] Optionally, the magnetic steel assembly and the magnetic member are respectively arranged at the first end and the second end of the rotor body, and the driving coil assembly and the magnetic levitation coil assembly are respectively arranged at the first end and the second end of the volute.

[0014] Optionally, the inner cavity of the volute comprises a first annular shell and a second annular shell, the first annular shell and the second annular shell are respectively located at the first end and the second end of the volute, the first annular shell and the volute form a first sealed cavity encapsulating the drive coil, the second annular shell and the volute form a second sealed cavity encapsulating the magnetic levitation coil assembly, the suspension cavity is formed between the first annular shell and the second annular shell, the first annular shell and the second annular shell are both ceramic structures, the drive coil assembly is arranged against the first annular shell, and the magnetic levitation coil is arranged against the second annular shell.

[0015] Optionally, the rotor body includes an annular body and a seat body, which are fixedly connected along the axial direction, and a liquid outlet is provided between the annular body and the seat body, the central through hole of the annular body is connected to the liquid outlet, the central through hole is coaxial with the medium inlet, each of the blades is located between the annular body and the seat body, the magnetic steel assembly is encapsulated inside the annular body, and the moving magnetic ring and the magnetic part are encapsulated inside the seat body.

[0016] Optionally, the seat body has an annular packaging cavity, the dynamic magnetic ring is sleeved on the inner annular wall of the annular packaging cavity, the magnetic part encapsulated in the seat body is located at the periphery of the dynamic magnetic ring, and along the radial direction, the axial height of the middle area of ​​the annular packaging cavity is greater than the axial height of the edge area.

[0017] Optionally, it also includes a base and a cover body, the cover body has a cylindrical barrel with an opening at one end and a guide cone connected to the other end of the cylindrical barrel, the opening of the cylindrical barrel is circumferentially sealed and buckled with the base, the static magnetic ring is fixed to the base by a threaded component and is located inside the cylindrical barrel, and the base is threadedly sealed and connected to the volute and is coaxial with the medium inlet, and the guide cone passes through the center hole of the annular packaging cavity and protrudes toward the medium inlet.

[0018] Optionally, a first auxiliary channel is formed between the outer circumferential surface and outer end surface of the annular body and the corresponding inner wall of the volute, a second auxiliary channel is formed between the outer circumferential surface and outer end surface of the annular packaging cavity and the corresponding inner wall of the volute, and between the inner circumferential wall of the annular packaging cavity and the cover body, and the outer end surface of the annular body and the outer end surface of the seat body both have a predetermined angle with the horizontal plane, and the distance between the outer end surface and the horizontal plane increases from the outside to the inside.

[0019] Optionally, the outer end surfaces of the annular body and the seat body are both provided with a plurality of protrusions, the protrusions extend from the inner edge side to the outer edge side, and the protrusions have a predetermined angle with the radial direction, and the distance between adjacent protrusions is smaller as they are closer to the inner edge side, or the height of the protrusions is lower as they are closer to the inner edge;

[0020] Optionally, the rotor is a centrifugal fully enclosed rotor structure, the blades are backward curved blades, the magnetic steel assembly and the magnetic member are respectively arranged at the first end and the second end of the rotor body, and the blades are located between the magnetic steel assembly and the magnetic member;

[0021] Alternatively or / and, the magnetic member comprises a magnetic ring.

[0022] The rotary drive and axial position control of the rotor in the present invention are completely independent and are located on both sides of the rotor body, respectively, and the control logic is relatively simple. In addition, the full suspension operation of the rotor can be achieved through the magnetic force between the dynamic magnetic ring and the static magnetic ring in the present invention, so that there is no mechanical contact between the rotor and the volute (equivalent to the stator), reducing heat and wear and minimizing the possibility of thrombosis and crushing damage to blood cells: the radial suspension limit of the rotor can be achieved by the dynamic magnetic ring and the static magnetic ring. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 A schematic diagram of the three-dimensional structure of a magnetic levitation centrifugal pump in one embodiment of the present invention;

[0024] Figure 2 It is a 3D cross-sectional view of a magnetic levitation centrifugal pump;

[0025] Figure 3 for Figure 1 A schematic cross-sectional structure diagram of ;

[0026] Figure 4 A schematic diagram of the structure of a rotor in an embodiment of the present invention;

[0027] Figure 5 for Figure 4 A schematic diagram of a cross-section of the rotor shown in another perspective;

[0028] Figure 6 A schematic diagram of the structure of a rotor body in an embodiment of the present invention;

[0029] Figure 7 is a schematic diagram of a rotor in another embodiment of the present invention;

[0030] Figure 8 FIG. 4 is a schematic diagram of a rotor in another embodiment of the present invention.

[0031] in, Figures 1 to 8 middle:

[0032] 100 rotor; 11 seat body; 111 lower cover plate; 112 annular sealing cavity; 113 inner peripheral wall; 12 annular body; 121 upper cover plate; 1211 outer end surface; 1212 protrusion; 13 blade; 14 magnetic steel assembly; 15 magnetic component; 16 moving magnetic ring; 17 magnetic component;

[0033] 200 volute; 201 first volute; 202 second volute; 203 first annular housing; 204 second annular housing; 21 driving coil assembly; 211 driving coil; 212 working iron core; 22 static magnetic ring; 23 base; 24 cover; 241 column; 242 guide cone; 26 position sensor; 27 magnetic levitation coil assembly; 271 magnetic levitation coil; 272 magnetic levitation iron core;

[0034] 300 import pipe;

[0035] 400 outlet pipe;

[0036] 1a first auxiliary flow channel; 1b second auxiliary flow channel; 100a liquid outlet. DETAILED DESCRIPTION

[0037] In the description of the present invention, it should be noted that the directions or positional relationships indicated by the terms "left", "right", "up", "down", "inside", "outside", etc. are based on the directions or positional relationships shown in the drawings, and are only for the convenience of describing the technology concisely, and do not indicate or imply that the device or element referred to must have a specific direction, specific orientation structure and operation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", etc. are only for the convenience of describing two or more structures or components with the same or similar structures and / or functions, and do not indicate any special limitation on the order and / or importance.

[0038] Without loss of generality, this article introduces the technical solution and technical effects by taking the application of a magnetic levitation centrifugal pump to heart pumping blood as an example. Those skilled in the art should understand that although the magnetic levitation centrifugal pump described in the present invention proposes a technical solution based on the research of blood pumps, the magnetic levitation centrifugal pump in this article is not limited to application to heart pumping blood, and its application in other fields is still within the protection scope of this article.

[0039] In order to enable those skilled in the art to better understand the technical solution of the present invention, the present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments.

[0040] Please refer to Figures 1 to 3 , Figure 1 A schematic diagram of the three-dimensional structure of a magnetic levitation centrifugal pump in one embodiment of the present invention; Figure 2 It is a 3D cross-sectional view of a magnetic levitation centrifugal pump; Figure 3 for Figure 1 Schematic diagram of the cross-sectional structure.

[0041] The invention provides a magnetic suspension centrifugal pump, comprising a volute, a static magnetic ring and a rotor. The volute is provided with a suspension cavity, a medium inlet and a medium outlet, and the rotor is located inside the suspension cavity.

[0042] The volute may include a first volute 201 and a second volute 202, which enclose the installation space of the rotor. The first volute 201 and the second volute 202 may be detachably installed to facilitate the installation and maintenance of the rotor and other parts. A medium inlet may be provided on the first volute 201, and a medium outlet may be enclosed by corresponding structures on the first volute 201 and the second volute 202. An inlet pipe 300 is installed at the medium inlet, and an outlet pipe 400 is installed at the medium outlet. The first volute 201, the second volute 202, the inlet pipe 300 and the outlet pipe 400 may all be made of titanium alloy.

[0043] Please refer to further Figure 4 and Figure 5 , Figure 4 A schematic diagram of the structure of a rotor in an embodiment of the present invention; Figure 5 for Figure 4 Schematic diagram of another view of the rotor shown.

[0044] The rotor in the present invention includes a rotor body, blades 13 , a moving magnetic ring 16 , a magnetic member 17 and a magnetic steel assembly 14 .

[0045] Among them, the rotor body mainly provides an installation basis for the installation of other parts constituting the rotor and cooperates with the volute for assembly. A specific structure of the rotor body will be specifically introduced later. The moving magnetic ring 16, the blades 13, the magnetic parts 17 and the magnetic steel assembly 14 are all installed on the rotor body. The number of blades 13 can be two or more, that is, the number of blades is at least two, and each blade is distributed along the circumferential direction. The blades 13 can be backward-bent blades. The backward-bent blades can obtain the most optimized fluid efficiency, shear force and streamline distribution. Under the same output flow and pressure requirements, the diameter of the rotor and the volute can be smaller, the requirements for motor speed and torque can be lower, and the volume of the volute, rotor and motor can be reduced. Under the condition of the same output capacity, the miniaturization of the pump can be achieved, and the possibility of hemolysis and thrombosis is minimized.

[0046] The number of blades 13 may be determined according to the specific volume of the pump, and may generally be 3 to 7 blades. For example, in a specific example, the number of blades is 5.

[0047] Of course, the blades 13 may also be blades of equal thickness or straight blades, as long as they can meet the use requirements.

[0048] The volute 200 is provided with a static magnetic ring 22, which is coaxial with the dynamic magnetic ring 16 and nested to limit the radial position of the rotor 100 and the volute 200. Both the static magnetic ring 22 and the dynamic magnetic ring 16 may include two or more annular magnets arranged in the axial direction. Figure 3 2 shows a specific example in which both the static magnetic ring 22 and the dynamic magnetic ring 16 have three annular magnetic rings, and the dynamic magnetic ring 16 is nested with the periphery of the static magnetic ring 22. Of course, the number of annular magnetic rings in the static magnetic ring 22 and the dynamic magnetic ring 16 is not limited to the description herein, and can also be other values.

[0049] During operation, the dynamic magnetic ring 16 and the static magnetic ring 22 define the radial position of the rotor relative to the volute 200. The radial suspension of the rotor is achieved by the repulsive force between the dynamic magnetic ring and the static magnetic ring. As mentioned above, the rotor body is equipped with a group of dynamic magnetic rings; the volute is equipped with a group of static magnetic rings; the dynamic magnetic ring and the static magnetic ring constitute a permanent magnetic radial suspension bearing. The static magnetic ring can adjust the axial position through the precision thread between the base 23 and the volute 200. In an ideal situation, the position of the static magnetic ring 22 is adjusted. When the rotor body is suspended axially in the middle of the volute suspension cavity, the axial position of the static magnetic ring 22 is just aligned with the dynamic magnetic ring 16. At this time, the radial stiffness of the permanent magnetic radial suspension bearing formed by the dynamic magnetic ring 16 and the static magnetic ring 22 is the maximum, and the axial force is 0.

[0050] The first end of the rotor body provided by the present invention is fixed with a magnetic steel assembly 14, and the magnetic steel assembly 14 includes N first magnetic steels 141 arranged along the circumferential direction, and the magnetic poles of all the first magnetic steels 141 are arranged in an alternating manner. Figure 4 , the first magnetic steel in the magnetic steel assembly is arranged alternately with the N pole and the S pole to form a circle. Each magnetic steel in the magnetic steel assembly 14 can be encapsulated inside the rotor body. In one example, the first magnetic steels 141 can fit tightly together to form a magnetic ring with a full pole arc, so that the disc motor formed with the drive coil assembly 21 installed on the volute 200 can obtain a greater motor efficiency.

[0051] Of course, the magnetic steel assembly 14 can also include transverse magnetic conductive magnetic steels 18, and the magnetic conductive magnetic steels 18 are located between the first magnetic steels 141, that is, an equal number of mutually exclusive transverse magnetic conductive magnetic steels 18 are arranged between the first magnetic steels 141 with staggered magnetic poles. For example, 10 groups of staggered first magnetic steels and magnetic conductive magnetic steels form a Halbach magnetic steel array (4-16 even groups are possible, and 10 groups are an optional solution). This magnetic steel array can have the effect of magnetic concentration, and the magnetic density between the air gaps of the motor is increased under the same magnetic steel volume, thereby further improving the motor efficiency.

[0052] Of course, the configuration of the magnetic steel assembly 14 is not limited to the method described in this article, and can also be other methods as long as the functions described in this article can be achieved.

[0053] Correspondingly, the first end of the volute 200 corresponding to the rotor mounted magnetic steel assembly 14 is encapsulated with a driving coil assembly 21, wherein the driving coil assembly 21 may include a driving coil 211 and a working iron core 212. During operation, the driving coil 211 is supplied with current to generate a magnetic field, and the working iron core 212 amplifies the magnetic field generated by the driving coil 211. The first magnetic steel 141 with staggered magnetic poles of the magnetic steel assembly 14 mounted on the rotor body will generate a rotational force to drive the rotor body to rotate. The driving coil assembly 21 and the magnetic steel assembly 14 mounted inside the rotor body form a disc motor.

[0054] When the magnetic levitation coil assembly 27 is powered, the magnetic part 17 and the magnetic levitation coil assembly 27 generate an axial force to control the axial position of the rotor body. By adjusting the current direction of the magnetic levitation coil assembly 27, the force direction between the magnetic levitation coil assembly 271 and the magnetic part 17 can be changed. The magnetic levitation coil assembly 27 may include a magnetic levitation coil 271 and a magnetic levitation core 272. The axial position of the rotor body may be obtained by a position sensor.

[0055] In this embodiment, the rotation drive and axial position control of the rotor are completely independent and are located on both sides of the rotor body, respectively, and the control logic is relatively simple. In addition, in the present invention, the full suspension operation of the rotor can be achieved through the magnetic force between the dynamic magnetic ring 16 and the static magnetic ring 22, so that there is no mechanical contact between the rotor 100 and the volute 200 (equivalent to the stator), reducing heat and wear and minimizing the possibility of thrombosis and crushing damage to blood cells: the radial suspension limit of the rotor 100 can be achieved by the dynamic magnetic ring and the static magnetic ring.

[0056] In this specific example, the inner cavity of the volute 200 has a first annular shell 203 and a second annular shell 204, the first annular shell 203 and the second annular shell 204 are respectively located at the first end and the second end of the volute, the first annular shell 203 and the volute form a first sealed cavity for encapsulating the drive coil, the second annular shell and the volute form a second sealed cavity for encapsulating the magnetic levitation coil assembly, the suspension cavity is formed between the first annular shell and the second annular shell, the first annular shell 203 and the second annular shell 204 are both ceramic structures, the drive coil assembly 21 is arranged against the first annular shell 203, and the magnetic levitation coil 271 is arranged against the second annular shell 204.

[0057] Each annular casing can be fixed to the volute by bonding or other means.

[0058] Ceramic materials have good compatibility with blood. Ceramic materials are very hard and insulating. In this way, the wall thickness of the annular shell can be relatively thin and the drive coil can be close to the inner wall, thereby greatly reducing the air gap between the drive coil and the first magnetic steel and completely eliminating eddy current losses. The first magnetic steel can be arranged in a Halbach array, which improves the efficiency of the motor and realizes the miniaturization of the blood pump while maintaining the maximum output capacity. Due to the insulating properties of ceramics, the risk of leakage current generated by the drive coil to the blood flowing in the volute can be minimized, and the possibility of the drive coil assembly and the first magnetic steel assembly forming a disc motor being disturbed by an external electric field is eliminated. For example: when a patient is receiving electric shock / electrical recovery / electrical knife cutting treatment, the magnetic levitation centrifugal pump can still work normally.

[0059] In one example, the rotor body includes an annular body 12 and a seat body 11, which are fixedly connected in the axial direction, each blade is located between the annular body 12 and the seat body 11, and there is a liquid outlet between the annular body 12 and the seat body 11, and the liquid outlet can be located between the two blades, and the central through hole of the annular body 12 is connected to the liquid outlet 100a, and the annular body 12 and the seat body 11 are both encapsulated with magnetic steel components, and the dynamic magnetic ring 16 is encapsulated inside the seat body 11. The annular body 12 and the seat body are fixedly connected in the axial direction, and there is a liquid outlet between the annular body 12 and the seat body 11, and the central through hole of the annular body 12 is connected to the liquid outlet, and the central through hole of the annular body 12 is coaxial with the medium inlet. The number of liquid outlets 100a can be multiple, evenly arranged along the circumferential direction, and the specific number can be determined according to the specific product, which is not limited in this article.

[0060] Specifically, the seat body has an annular packaging cavity, the dynamic magnetic ring is sleeved on the inner ring wall of the annular packaging cavity, the magnetic part encapsulated in the seat body is located on the periphery of the dynamic magnetic ring, and along the radial direction, the axial height of the middle area of ​​the annular packaging cavity is greater than the axial height of the edge area.

[0061] This can minimize the space occupied by the packaging cavity in the fluid inside the pump, which is conducive to a compact structure.

[0062] For easy installation, the annular packaging cavity can be formed by the following method: an annular groove is provided on the base body, and the lower cover plate 111 covers the notch of the annular groove to form a sealed chamber. Similarly, the sealed cavity for installing the magnetic steel assembly on the annular body can also be formed by providing an annular groove and an upper cover plate 121 to cooperate with the sealing method.

[0063] The rotor in the present invention can be a centrifugal fully enclosed rotor. When the centrifugal pump is working, a large amount of blood flows into the centrifugal pump through the inflow channel, is accelerated by the rotor centrifugal blades, flows out through the outflow channel, and injects the blood into the aorta, providing pressure and flow for the blood circulation of the whole body. The rotor centrifugal blades can be a hollow structure.

[0064] The static magnetic ring in the above-mentioned embodiments can be installed inside the volute in the following manner.

[0065] In one example, the magnetic levitation centrifugal pump can further include a base and a cover 24 that is buckled on the base 23. The cover 24 is sealed and fixed to the base, and the static magnetic ring is fixed to the base through a threaded component. The threaded component can be a screw, a bolt, or a screw. In addition, the static magnetic ring is installed in the installation space formed by the cover and the base. The second end of the volute is provided with a mounting through hole, which is coaxial with the medium inlet, and the base 23 is threaded and sealed to the mounting through hole. The cover 24 includes a cylinder 241 with an opening at one end and a guide cone 242 connected to the other end of the cylinder. The static magnetic ring 22 is located inside the cylinder 241, and the guide cone 242 passes through the center hole of the seat 11 and protrudes toward the medium inlet. The closer the guide cone 242 is to the medium inlet, the smaller the radial dimension, so that the fluid at the volute medium inlet can flow evenly in the circumferential direction under the diversion of the guide cone, and then evenly enter between the blades.

[0066] In the above embodiment, the base and the volute are connected via threads, and the axial position of the base relative to the volute can be accurately adjusted to precisely match the moving magnetic ring on the rotor.

[0067] Please refer to Figure 6 and Figure 7 In the above embodiments, the outer end surface of the annular body 12 and the outer end surface of the seat body are both provided with a plurality of protrusions 1212 (only the protrusions on the outer end surface of the annular body are shown in the figure), the protrusions extend from the inner edge side to the outer edge side, and the protrusions 1212 have a predetermined angle with the radial direction, the distance between adjacent protrusions is smaller as they are closer to the inner edge side, and the protrusions 1212 are in an inner spiral structure. In this way, a hydrodynamic liquid floating bearing is formed between the outer end surface of the annular body and the first annular shell, and between the outer end surface of the seat body and the second annular shell. When the rotor is greatly disturbed in the axial direction and one end approaches the annular shell on that side, the hydrodynamic liquid floating bearing can provide additional restoring force toward the center, thereby improving the stability of the impeller along the axial direction.

[0068] Of course, the closer the protrusion 1212 is to the inner edge, the lower the height is, and the above technical effect can also be achieved. Figure 7 shown.

[0069] In a specific embodiment, a first auxiliary channel is formed between the outer circumferential surface of the annular body, the outer end case and the corresponding inner wall of the volute, and a second auxiliary channel is formed between the outer circumferential surface of the annular packaging cavity, the outer end face and the corresponding inner wall of the volute, and between the inner circumferential wall 113 of the annular packaging cavity and the cover body 24.

[0070] During operation, the rotor is suspended in the middle of the volute 200 and rotates at a high speed. The blades between the annular body 12 and the seat body 11 and the inner wall of the volute 200 constitute the main flow channel of the pump. Blood flows in from the medium inlet, enters the main flow channel between the blades through the central through hole of the annular body, and after being accelerated by the rotation of the blades, enters the main flow channel inside the volute and flows out of the volute through the medium outlet.

[0071] At the same time, a small portion of the blood entering the main flow channel inside the volute 200 flows back to the inlet of the rotor body through the first auxiliary channel and the second auxiliary channel, re-enters between the blades and flows into the volute after acceleration. Through the above design, all the flow channels for blood entering the centrifugal pump are unidirectional, and there is no stationary or reflux area, thereby minimizing the possibility of thrombosis.

[0072] At the same time, as mentioned above, since the annular shell opposite to the end surface of the annular body and the seat body is made of ceramic material, its surface is hard and smooth, and when the rotor accidentally contacts the annular shell, the possibility of the surface of the annular shell being damaged is reduced. Because the motor efficiency is higher, under the same conditions, the thickness of the first magnetic steel in the rotor can be thinner, and the thickness of the outer end wall (cover plate) of the annular body 12 and the seat body 11 is also correspondingly thinned, thereby reducing the length of the return flow channel in the volute.

[0073] At the same time, the outer end faces of the annular body and the outer end faces of the seat body have a predetermined angle with the horizontal plane, and the distance between the outer end faces and the horizontal plane increases from the outside to the inside, that is, the outer end faces of the annular body and the seat body are concave inward, and the upper and lower outer end faces of the rotor have inward conical surfaces. Therefore, the outer gap of the auxiliary channel formed between the outer end face and the inner wall of the volute is smaller, and the inner gap is larger. In this way, when blood passes through the area with smaller outer gap, the shear force is relatively high but the flow rate is fast and the passing time is short. When passing through the area with larger inner gap, the relative flow rate is low but the shear force is also low, which minimizes the possibility of hemolysis and thrombosis. In this way, it is possible to relatively reduce the gap of the auxiliary channel, reduce the reflux loss of the centrifugal pump, and improve the fluid efficiency. Under the same output flow / pressure requirements of the centrifugal pump, the diameter of the rotor and the volute can be smaller, and the requirements for motor speed and torque can be lower, thereby reducing the volume of the volute / rotor and realizing the miniaturization of the centrifugal pump under the condition of the same output capacity.

[0074] The position sensor may be a Hall sensor or an eddy current sensor, as long as it can detect the axial position of the rotor body.

[0075] The above is a detailed introduction to a magnetic levitation centrifugal pump provided by the present invention. This article uses specific examples to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only used to help understand the method and core ideas of the present invention. It should be pointed out that for ordinary technicians in this technical field, without departing from the principles of the present invention, the present invention can also be improved and modified in a number of ways, and these improvements and modifications also fall within the scope of protection of the claims of the present invention.

Claims

1. A magnetic levitation centrifugal pump, characterized in that: It includes a volute, a static magnetic ring and a rotor; The volute has a suspension cavity, a medium inlet and a medium outlet, the rotor is located inside the suspension cavity, and the static magnetic ring is fixed to the volute. The rotor comprises a rotor body, a moving magnetic ring positioned on the rotor body, and at least two blades; the moving magnetic ring is coaxial with the static magnetic ring and is nested to limit the radial position of the rotor body and the volute; The rotor body is fixed with a magnetic steel assembly, the magnetic steel assembly includes N first magnetic steels arranged in the circumferential direction, and the magnetic poles of all the first magnetic steels are arranged in a staggered manner; the rotor body is also fixed with a magnetic member, the magnetic member includes at least one of a magnetic ring and an iron core; The volute encapsulates a driving coil assembly arranged opposite to the magnetic steel assembly, and the driving coil assembly cooperates with the magnetic steel assembly to make the rotor body rotate circumferentially; the volute is fixed with a magnetic levitation coil assembly, and when the magnetic levitation coil assembly is energized, the magnetic member and the magnetic levitation coil assembly generate an axial force; The rotor body includes an annular body and a seat body, which are fixedly connected along the axial direction, and a liquid outlet is provided between the annular body and the seat body. The central through hole of the annular body is connected to the liquid outlet, and the central through hole is coaxial with the medium inlet. Each of the blades is located between the annular body and the seat body, and the magnetic steel assembly is encapsulated inside the annular body, and the dynamic magnetic ring and the magnetic component are encapsulated inside the seat body.

2. The magnetic levitation centrifugal pump according to claim 1, characterized in that: Also includes a position sensor for detecting the axial position of the rotor body; Alternatively or alternatively, adjacent first magnetic steels are closely fitted together, or the magnetic steel assembly further includes a transverse magnetic conductive steel, the magnetic conductive steel is located between two first magnetic steels, and all the magnetic conductive steels and all the first magnetic steels form a Halbach magnetic steel array.

3. The magnetic levitation centrifugal pump according to claim 1, characterized in that: The magnetic steel assembly and the magnetic member are respectively arranged at the first end and the second end of the rotor body, and the driving coil assembly and the magnetic levitation coil assembly are respectively arranged at the first end and the second end of the volute.

4. The magnetic levitation centrifugal pump according to any one of claims 1 to 3, characterized in that: The inner cavity of the volute is provided with a first annular shell and a second annular shell, the first annular shell and the second annular shell are respectively located at the first end and the second end of the volute, the first annular shell and the volute form a first sealed cavity encapsulating the drive coil, the second annular shell and the volute form a second sealed cavity encapsulating the magnetic levitation coil assembly, the suspension cavity is formed between the first annular shell and the second annular shell, the first annular shell and the second annular shell are both ceramic structures, the drive coil assembly is arranged against the first annular shell, and the magnetic levitation coil is arranged against the second annular shell.

5. The magnetic levitation centrifugal pump according to any one of claims 1 to 3, characterized in that: The seat body has an annular packaging cavity, the dynamic magnetic ring is sleeved on the inner ring wall of the annular packaging cavity, the magnetic part encapsulated in the seat body is located at the periphery of the dynamic magnetic ring, and along the radial direction, the axial height of the middle area of ​​the annular packaging cavity is greater than the axial height of the edge area.

6. The magnetic levitation centrifugal pump according to claim 5, characterized in that: It also includes a base and a cover body, the cover body has a cylindrical barrel with an opening at one end and a guide cone connected to the other end of the cylindrical barrel, the opening of the cylindrical barrel is circumferentially sealed and buckled with the base, the static magnetic ring is fixed to the base by a threaded component and is located inside the cylindrical barrel, and the base is thread-sealed and connected to the volute and is coaxial with the medium inlet, and the guide cone passes through the central hole of the annular packaging cavity and protrudes toward the medium inlet.

7. The magnetic levitation centrifugal pump according to claim 6, characterized in that: A first auxiliary channel is formed between the outer circumferential surface and outer end surface of the annular body and the corresponding inner wall of the volute, a second auxiliary channel is formed between the outer circumferential surface and outer end surface of the annular packaging cavity and the corresponding inner wall of the volute, and between the inner circumferential wall of the annular packaging cavity and the cover body, and the outer end surface of the annular body and the outer end surface of the seat body both have a predetermined angle with the horizontal plane, and the distance between the outer end surface and the horizontal plane increases from the outside to the inside.

8. The magnetic levitation centrifugal pump according to any one of claims 1 to 3, characterized in that: The outer end faces of the annular body and the seat body are both provided with a plurality of protrusions, which extend from the inner edge side to the outer edge side and have a predetermined angle with the radial direction. The distance between adjacent protrusions is smaller as it is closer to the inner edge side or the height of the protrusion is lower as it is closer to the inner edge.

9. The magnetic levitation centrifugal pump according to claim 1 or 2, characterized in that: The rotor is a centrifugal fully enclosed rotor structure, the blades are backward curved blades, the magnetic steel assembly and the magnetic member are respectively arranged at the first end and the second end of the rotor body, and the blades are located between the magnetic steel assembly and the magnetic member; Alternatively or / and, the magnetic member comprises a magnetic ring.

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