Magnetic suspension type centrifugal pump

Abstract

According to the magnetic suspension type centrifugal pump, axial force is provided through magnetic steel assemblies arranged at the two ends of a rotor and corresponding driving coil assemblies on a volute, additional coils and sensor assemblies are not needed, and the size and the weight can be greatly reduced; the position of the rotor body is controlled by adjusting the upper and lower disc type motors, and no extra power consumption is generated due to position control; due to the fact that the axial position control does not need a sensor assembly, the centrifugal pump implanted into the body is not provided with an electronic device, the anti-interference capacity is higher, the reliability is higher, and the performance does not decline along with the prolonging of working time. Therefore, compared with the prior art, the axial suspension technology can realize high reliability and miniaturization of the blood pump.

Description

[0001] This application is a divisional application. The application number of the parent application is 202210565532.4, 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 out enough blood flow to maintain blood circulation throughout the body. 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 therapy, 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 devices (Ventricular Assist Device, VAD) have 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 and a moving magnetic ring positioned on the rotor body; 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 also fixed with a magnetic steel assembly, wherein the magnetic steel assembly includes N first magnetic steels arranged along the circumferential direction, and the magnetic poles of all the first magnetic steels are arranged in a staggered manner;

[0010] The two ends of the volute are also encapsulated with driving coil assemblies, and the two driving coil assemblies cooperate with the magnetic steel assembly to provide axial force and rotational force for the axial movement of the rotor body.

[0011] The centrifugal pump provided by the present invention provides axial limit through the magnetic steel components arranged at both ends of the rotor body and the corresponding driving coil components on the volute, without the need for additional coils and sensor components, and no additional power consumption is generated due to position control; because the axial position control does not require sensor components, the centrifugal pump implanted in the body has no electronic devices, has stronger anti-interference ability, higher reliability, and the performance does not decrease with the extension of working time. Therefore, compared with the existing technology, this axial suspension technology can achieve high reliability and miniaturization of the blood pump.

[0012] 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 and the static magnetic ring, so that there is no mechanical contact between the rotor and the volute (equivalent to the stator), which reduces heat and wear and minimizes the possibility of thrombosis and crushing damage to blood cells: the radial suspension limit of the rotor can be achieved by relying on the dynamic magnetic ring and the static magnetic ring.

[0013] Optionally, the magnetic steel components are provided at both ends of the rotor body, the magnetic steel components at both ends of the rotor body are symmetrical about the central cross section of the rotor body, the driving coil components at both ends of the volute are symmetrical about the central cross section of the suspension chamber, the magnetic steel components and the driving coil components on the same side form a group of disc motors, and the disc motors at both ends jointly provide the axial force and rotational force of the rotor body along the axial movement;

[0014] Alternatively or / and, adjacent first magnetic steels are closely fitted, 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.

[0015] Optionally, at least one end of the rotor body is also encapsulated with a magnetic component, and the corresponding end of the volute is encapsulated with a magnetic levitation coil. When the magnetic levitation coil is energized, the magnetic levitation coil and the magnetic component generate axial force; wherein the magnetic component includes at least one of an iron core or a second magnetic steel.

[0016] Optionally, the magnetic components are encapsulated at both ends of the rotor body, and the two magnetic components are symmetrical about the central cross-section of the rotor body, and the magnetic levitation coils are encapsulated at both ends of the volute, and the two magnetic levitation coils are symmetrical about the central cross-section of the suspension chamber.

[0017] Optionally, there are multiple magnetic components, which are evenly arranged along the circumferential direction, and the magnetic components are arranged between adjacent first magnetic steels;

[0018] Alternatively or alternatively, the magnetic component and the first magnetic steel are axially overlapped;

[0019] Alternatively or alternatively, the magnetic levitation coil and the driving coil assembly are arranged to overlap in the axial direction.

[0020] Optionally, the inner cavity of the volute has an annular shell, the annular shell and the volute form a sealed cavity, the drive coil assembly is located in the sealed cavity, the suspension cavity is formed between two annular shells located at both ends, the annular shell is a ceramic structure, and the drive coil assembly is arranged close to the annular shell.

[0021] 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, a central through hole of the annular body is connected to the liquid outlet, the central through hole is coaxial with the medium inlet, blades are provided between the annular body and the seat body to form a fully enclosed rotor structure, the magnetic steel assembly is encapsulated inside the annular body and the seat body, and the moving magnetic ring is encapsulated inside the seat body.

[0022] Optionally, the seat body has a first annular packaging cavity, the dynamic magnetic ring is sleeved on the inner ring wall of the first annular packaging cavity, the first iron core and magnetic steel assembly encapsulated in the seat body are located outside the dynamic magnetic ring, and along the radial direction, the axial height of the middle area of ​​the first annular packaging cavity is greater than the axial height of the edge area.

[0023] 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 section, 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 first annular packaging cavity and protrudes toward the medium inlet.

[0024] Optionally, a first auxiliary channel is formed between the outer circumferential wall, outer end wall of the annular body and the corresponding inner wall of the volute, a second auxiliary channel is formed between the outer circumferential wall, outer end wall of the first annular packaging cavity and the corresponding inner wall of the volute, and between the inner circumferential wall of the first 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.

[0025] 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;

[0026] Alternatively or / and, the blades are backward curved blades.

[0027] Optionally, the rotor body is an annular shell, the number of the magnetic steel assembly is one, each of the first magnetic steels is encapsulated in the inner cavity of the annular shell, each of the first magnetic steels extends from one end of the rotor body to the other end, and the end surface of the annular shell facing the medium inlet of the volute has at least two grooves, the opening of the grooves faces the medium inlet of the volute, the grooves are located between adjacent first magnetic steels, and the grooves form the main liquid flow channel of the rotor body. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 A schematic diagram of the three-dimensional structure of a magnetic levitation centrifugal pump in one embodiment of the present invention;

[0029] Figure 2 It is a 3D cross-sectional view of a magnetic levitation centrifugal pump;

[0030] Figure 3 for Figure 1 A schematic cross-sectional structure diagram of ;

[0031] Figure 4 A schematic diagram of the structure of a rotor in an embodiment of the present invention;

[0032] Figure 5 for Figure 4 a schematic diagram of another view of the rotor shown;

[0033] Figure 6 is a schematic diagram of a rotor in another embodiment of the present invention;

[0034] Figure 7 A schematic diagram of a rotor in another embodiment of the present invention;

[0035] Figure 8 A cross-sectional schematic diagram of a magnetic suspension centrifugal pump in a second embodiment of the present invention;

[0036] Fig. 9 For the present invention Figure 8 A schematic cross-sectional view of the rotor shown;

[0037] Fig.10 A schematic diagram of a rotor in another embodiment of the present invention;

[0038] Fig.11 for Fig.10 A partial cross-sectional view of the rotor shown.

[0039] in, Figures 1 to 11 middle:

[0040] 100 rotor; 11 seat body; 111 lower cover plate; 112 first annular packaging 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 dynamic magnetic ring; 18 magnetic conductive magnetic steel;

[0041] 100' rotor; 14 magnetic steel assembly; 141 first magnetic steel; 110 annular shell; 120 slot body; 111' cover plate;

[0042] 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 core; 22 static magnetic ring; 23 base; 24 guide cone; 25 magnetic levitation coil;

[0043] 300 import pipe;

[0044] 400 outlet pipe;

[0045] 1a first auxiliary channel; 1b second auxiliary channel; 100a liquid outlet. DETAILED DESCRIPTION

[0046] 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.

[0047] 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.

[0048] 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.

[0049] 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.

[0050] The present invention provides a magnetic suspension centrifugal pump, comprising a volute 200, a static magnetic ring 22 and a rotor 100. The volute 200 has a suspension cavity, a medium inlet and a medium outlet, and the rotor 100 is located inside the suspension cavity.

[0051] The volute 200 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. The first volute may be provided with a medium inlet, and the medium outlet may be enclosed by corresponding structures on the first volute and the second volute. The medium inlet is provided with an inlet pipe, and the medium outlet is provided with an outlet pipe. The first volute, the second volute, the inlet pipe and the outlet pipe may all be made of titanium alloy.

[0052] 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.

[0053] The rotor in the present invention includes a rotor body, blades 13 , a moving magnetic ring 16 and a magnetic steel assembly 14 .

[0054] Among them, the rotor body mainly provides an installation basis for the installation of other components that constitute the rotor and is assembled with the volute. A specific structure of the rotor body will be specifically introduced later. The moving magnetic ring, blades and magnetic steel components are all installed on the rotor body. The number of blades 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 can be backward-curved blades. The backward-curved 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 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.

[0055] The number of blades 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.

[0056] Of course, the blades may also be blades of equal thickness or straight blades, as long as they can meet the use requirements.

[0057] The volute 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 and the volute. Both the static magnetic ring and the dynamic magnetic ring may include two or more annular magnets arranged in the axial direction. Figure 3 A specific example is shown in which both the static magnetic ring and the dynamic magnetic ring have three annular magnetic rings, and the dynamic magnetic ring is nested on the periphery of the static magnetic ring. Of course, the number of annular magnetic rings in the static magnetic ring and the dynamic magnetic ring is not limited to the description in this article, and can also be other values. 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 and the volute, and the radial suspension of the rotor is achieved by the repulsive force between the dynamic magnetic ring and the static magnetic ring.

[0058] The two ends of the rotor body provided by the present invention are fixed with a magnetic steel assembly 14, which includes N first magnetic steels 141 arranged along the circumferential direction, and the magnetic poles of all the first magnetic steels 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 can be encapsulated inside the rotor body. In one example, the first magnetic steels 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 installed on the volute can obtain a higher motor efficiency.

[0059] Of course, the magnetic steel assembly can also include transverse magnetic conductive steel 18, which is located between the first magnetic steels, that is, an equal number of mutually exclusive transverse magnetic conductive steels are arranged between the first magnetic steels with staggered magnetic poles. For example, 10 groups of staggered first magnetic steels and magnetic conductive steels form a Halbach magnetic steel array (4-16 even groups are acceptable, 10 groups are an optional solution). This magnetic steel array can have the effect of magnetic concentration, which increases the magnetic density between the air gaps of the motor under the same magnetic steel volume, thereby further improving the motor efficiency.

[0060] Of course, the configuration of the magnetic steel assembly 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.

[0061] Correspondingly, the ends of the volute and the rotor corresponding to the magnetic steel assembly are both encapsulated with a drive coil assembly 21, wherein the drive coil assembly may include a drive coil 211 and a working iron core 212. The drive coil assemblies at both ends may be symmetrically arranged about the central cross section of the suspension cavity, or may be asymmetrically arranged. During operation, the drive coil is supplied with an alternating current to generate a magnetic field, and the working iron core amplifies the magnetic field generated by the drive coil. The first magnetic steel with staggered magnetic poles of the magnetic steel assembly installed on the rotor body will generate an axial force. The controller detects the difference in electromotive force or inductance feedback from the upper and lower drive coils to confirm the difference in the position of the rotor from the upper and lower drive coils, thereby adjusting the drive parameters of the upper and lower drive coils (not limited to current, voltage, duty cycle, etc.) to change the magnitude of the axial force generated by the drive coil on the first magnetic steel in the rotor, thereby controlling the axial position of the rotor, so that the rotor body is always balanced and suspended at a central position equal to the upper and lower end walls of the volute under the action of the axial electromagnetic force of the motor.

[0062] This suspension method can significantly reduce the volume and weight because it does not require additional coils and sensor components; the control of the rotor body position is achieved by adjusting the current of the upper and lower motors, and there is no additional power consumption due to position control; because the axial position control does not require sensor components, the centrifugal pump implanted in the body has no electronic devices, has stronger anti-interference ability, higher reliability, and the performance does not decrease with the extension of working time. Therefore, compared with the existing technology, this axial suspension technology can achieve high reliability and miniaturization of the blood pump.

[0063] 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 and the static magnetic ring, so that there is no mechanical contact between the rotor and the volute (equivalent to the stator), which reduces heat and wear and minimizes the possibility of thrombosis and crushing damage to blood cells: the radial suspension limit of the rotor can be achieved by relying on the dynamic magnetic ring and the static magnetic ring.

[0064] Please refer to Figure 8 and Fig. 9 , Figure 8A cross-sectional schematic diagram of a magnetic suspension centrifugal pump in a second embodiment of the present invention; Fig. 9 For the present invention Figure 8 A schematic cross-sectional view of the rotor shown.

[0065] In order to simplify the control logic, at least one end of the rotor body in the present invention is also encapsulated with a magnetic component 15, and the accompanying drawings show a specific example in which both ends of the rotor body are encapsulated with magnetic components. The magnetic component can be at least one of an iron core or a second magnetic steel. The corresponding end of the volute is also encapsulated with a magnetic levitation coil 25. When the magnetic levitation coil is passed through a direct current, the magnetic levitation coil and the magnetic component generate an axial force.

[0066] When magnetic components are encapsulated at both ends of the rotor body, the two magnetic components can be symmetrical about the central cross-section of the rotor body, and magnetic levitation coils are encapsulated at both ends of the volute, and the two magnetic levitation coils are symmetrical about the central cross-section of the suspension cavity. The symmetrical arrangement facilitates control.

[0067] In this way, the rotation of the rotor body can be achieved by controlling the current of the drive coil, and the axial position of the rotor body can be adjusted by controlling the current of the magnetic levitation coil.

[0068] In a specific example, the number of magnetic components can be multiple, and they are evenly arranged along the axial direction. The magnetic components are arranged between adjacent first magnetic steels, wherein Fig. 9 The specific implementation of the arrangement of the magnetic components and the first magnetic steel in an alternating manner is shown in FIG. The magnetic suspension centrifugal pump of this implementation has a relatively compact structure.

[0069] Of course, the magnetic component and the first magnetic steel may also be arranged to be stacked in the axial direction.

[0070] In this specific example, the inner cavity of the volute has an annular shell, and the annular shell and the volute form a sealed cavity. The drive coil assembly is located in the sealed cavity. Of course, for the above-mentioned embodiment with a magnetic levitation coil, the magnetic levitation coil is also located in the sealed cavity. The suspension cavity is formed between the two annular shells at both ends. This article defines the annular shell installed on the first volute as the first annular shell 203, and the annular shell installed on the second volute as the second annular shell 204. In other words, the rotor body can reciprocate axially between the two annular shells. The annular shell is a ceramic structure.

[0071] The annular casing can be fixed to the volute by bonding or other means.

[0072] 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 achieves the miniaturization of the blood pump while maintaining the maximum output capacity. The insulating properties of ceramics can also minimize the risk of leakage current generated by the drive coil to the blood flowing in the volute, and eliminate the possibility of the drive coil assembly and the first magnetic steel assembly forming a disc motor that is disturbed by an external electric field. For example: when a patient is receiving electric shock / electrical recoil / electrical knife cutting treatment, the magnetic levitation centrifugal pump can still work normally.

[0073] Please refer to Figure 6 and Figure 7 , Figure 6 is a schematic diagram of a rotor in another embodiment of the present invention; Figure 7 FIG. 4 is a schematic diagram of a rotor in another embodiment of the present invention.

[0074] In one example, the rotor body includes an annular body 12 and a seat body 11, which are fixedly arranged along the axial direction, and a liquid outlet 100a is provided 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 each blade is located between the annular body 12 and the seat body 11, and magnetic steel components are encapsulated inside the annular body 12 and the seat body 11, and the dynamic magnetic ring is encapsulated inside the seat body 11. The annular body 12 and the seat body 11 are fixedly arranged along the axial direction, and a liquid outlet is provided 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, and the number of liquid outlets can be multiple, and they are 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.

[0075] Specifically, the seat body 11 has a first annular packaging cavity 111, the dynamic magnetic ring is sleeved on the inner ring wall of the first annular packaging cavity, the first iron core and magnetic steel assembly encapsulated in the seat body 11 are located on the periphery of the dynamic magnetic ring, and along the radial direction, the axial height of the middle area of ​​the first annular packaging cavity is greater than the axial height of the edge area.

[0076] This can minimize the space occupied by the packaging cavity in the fluid inside the pump, which is conducive to a compact structure.

[0077] For easy installation, the first annular packaging cavity can be formed by the following method: an annular groove is provided on the base body 11, 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 12 can also be formed by providing an annular groove and an upper cover plate 121 to cooperate in sealing.

[0078] 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 are hollow structures.

[0079] See also Fig.10 and Fig.11 In another specific embodiment, the rotor body 100' includes an annular shell 110, the number of the magnetic steel assembly 14 can be one, each first magnetic steel 141 is encapsulated in the inner cavity of the annular shell 110, and the first magnetic steel 141 extends from one end of the rotor body to the other end, and the N pole and S pole of the first magnetic steel 141 are respectively close to the two ends of the annular shell 110, and the end surface of the annular shell 110 facing the medium inlet of the volute also has at least two slots 120, the opening of the slots 120 faces the medium inlet of the volute, and the slots 120 are located between adjacent first magnetic steels. The slots 120 form the main liquid flow channel of the rotor body, that is, in this embodiment, the medium entering from the medium inlet of the volute flows out from the slots 120 to flow to the medium outlet, and the rotor 100' can be a centrifugal semi-closed rotor structure. The installation method of the moving magnetic ring 16 in the rotor can be the same as that of the above embodiment.

[0080] The static magnetic ring in the above-mentioned embodiments can be installed inside the volute in the following manner.

[0081] In one example, the magnetic levitation centrifugal pump can further include a base and a cover body that is snapped onto the base. The cover body is sealed and fixed to the base. 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 body and the base. The second end of the volute is provided with a mounting through hole. The mounting through hole is coaxial with the medium inlet, and the base thread is sealed and connected to the mounting through hole. The cover body includes a cylindrical barrel with an opening at one end and a guide cone 24 connected to the other end of the cylindrical barrel. The static magnetic ring is located inside the cylindrical barrel. The guide cone passes through the center hole of the seat body 11 and protrudes toward the medium inlet. The closer the guide cone is to the medium inlet, the smaller the radial dimension is. In this way, the fluid at the medium inlet of the volute can flow evenly in the circumferential direction under the diversion of the guide cone, and then evenly enter between the blades.

[0082] In the above embodiment, the base 23 is connected to the volute through a threaded connection, and the axial position of the base relative to the volute can be accurately adjusted to accurately match the moving magnetic ring on the rotor.

[0083] Please refer to Fig. 9In the above embodiments, the outer end surface 1211 of the annular body 12 and the outer end surface (not numbered) of the seat body 11 are both provided with a plurality of protrusions 1212, which 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, and the protrusions 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 12 and the upper annular shell, and between the outer end surface of the seat body 11 and the lower 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.

[0084] Please refer to Fig.10 Of course, the closer the protrusion is to the inner edge, the lower the height is, and the above-mentioned technical effect can still be achieved.

[0085] In a specific embodiment, a first auxiliary channel is formed between the outer peripheral wall, outer end wall of the annular body 12 and the corresponding inner wall of the volute, and a second auxiliary channel is formed between the outer peripheral wall, outer end wall of the first annular packaging cavity and the corresponding inner wall of the volute, and between the inner peripheral wall 113 of the first annular packaging cavity and the cover body.

[0086] During operation, the rotor is suspended in the middle of the volute 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 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 12, 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.

[0087] At the same time, a small part of the blood entering the main flow channel inside the volute flows back to the inlet of the rotor body through the first auxiliary channel 1a and the second auxiliary channel 1b, 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.

[0088] At the same time, as mentioned above, since the annular shell opposite to the end faces of the annular body 12 and the seat body 11 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.

[0089] At the same time, the outer end faces of the annular body 12 and the outer end faces of the seat body 11 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 12 and the seat body 11 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 a 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 a 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.

[0090] 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 and a moving magnetic ring positioned on the rotor body; 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 also fixed with a magnetic steel assembly (14), wherein the magnetic steel assembly comprises N first magnetic steels arranged in a circumferential direction, and the magnetic poles of all the first magnetic steels are arranged in a staggered manner; The two ends of the volute are also encapsulated with drive coil assemblies, and the two drive coil assemblies cooperate with the magnetic steel assembly to provide axial force and rotational force for the rotor body to move axially; At least one end of the rotor body is also encapsulated with a magnetic component, and the corresponding end of the volute is encapsulated with a magnetic levitation coil. When the magnetic levitation coil is energized, the magnetic levitation coil and the magnetic component generate axial force; wherein the magnetic component includes at least one of an iron core or a second magnetic steel.

2. The magnetic levitation centrifugal pump according to claim 1, characterized in that: The magnetic steel components are provided at both ends of the rotor body, the magnetic steel components at both ends of the rotor body are symmetrical about the central cross section of the rotor body, the driving coil components at both ends of the volute are symmetrical about the central cross section of the suspension chamber, the magnetic steel components and the driving coil components on the same side form a group of disc motors, and the disc motors at both ends jointly provide the axial force and rotational force of the rotor body along the axial movement; Alternatively or / and, adjacent first magnetic steels are closely fitted, 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 components are encapsulated at both ends of the rotor body, and the two magnetic components are symmetrical about the central cross section of the rotor body. The magnetic levitation coils are encapsulated at both ends of the volute, and the two magnetic levitation coils are symmetrical about the central cross section of the suspension chamber.

4. The magnetic levitation centrifugal pump according to claim 1, characterized in that: There are multiple magnetic components, which are evenly arranged along the circumferential direction, and the magnetic components are arranged between adjacent first magnetic steels; Alternatively or alternatively, the magnetic component and the first magnetic steel are axially overlapped; Alternatively or alternatively, the magnetic levitation coil and the driving coil assembly are arranged to overlap in the axial direction.

5. The magnetic levitation centrifugal pump according to claim 1 or 2, characterized in that: The inner cavity of the volute has an annular shell, the annular shell and the volute form a sealed cavity, the drive coil assembly is located in the sealed cavity, the suspension cavity is formed between two annular shells located at both ends, the annular shell is a ceramic structure, and the drive coil assembly is arranged close to the annular shell.

6. The magnetic levitation centrifugal pump according to claim 2, characterized in that: The rotor body includes an annular body and a seat body, which are fixedly connected in the axial direction, and a liquid outlet is provided between the annular body and the seat body, a central through hole of the annular body is connected to the liquid outlet, and the central through hole is coaxial with the medium inlet, and blades are provided between the annular body and the seat body to form a fully enclosed rotor structure, the magnetic steel assembly is encapsulated inside the annular body and the seat body, and the dynamic magnetic ring is encapsulated inside the seat body.

7. The magnetically suspended centrifugal pump according to claim 6, characterized in that: The seat body has a first annular packaging cavity, the dynamic magnetic ring is sleeved on the inner ring wall of the first annular packaging cavity, the first iron core and magnetic steel assembly encapsulated in the seat body are located on the periphery of the dynamic magnetic ring, and along the radial direction, the axial height of the middle area of ​​the first annular packaging cavity is greater than the axial height of the edge area.

8. The magnetic levitation centrifugal pump according to claim 7, characterized in that: It also includes a base and a cover body, the cover body has a column with an opening at one end and a guide cone connected to the other end of the column segment, the opening of the column 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 column, 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 first annular packaging cavity and protrudes toward the medium inlet.

9. The magnetic levitation centrifugal pump according to claim 6, characterized in that: A first auxiliary channel is formed between the outer peripheral wall, outer end wall of the annular body and the corresponding inner wall of the volute, a second auxiliary channel is formed between the outer peripheral wall, outer end wall of the first annular packaging cavity and the corresponding inner wall of the volute, and between the inner peripheral wall of the first 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.

10. The magnetic levitation centrifugal pump according to claim 6, characterized in that: 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; Alternatively or / and, the blades are backward curved blades.

11. The magnetic levitation centrifugal pump according to claim 1, characterized in that: The rotor body is an annular shell, the number of the magnetic steel assembly is one, each of the first magnetic steels is encapsulated in the inner cavity of the annular shell, each of the first magnetic steels extends from one end of the rotor body to the other end, the end surface of the annular shell facing the medium inlet of the volute has at least two grooves, the openings of the grooves face the medium inlet of the volute, the grooves are located between adjacent first magnetic steels, and the grooves form the main liquid flow channel of the rotor body.

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