Magnetic levitation type centrifugal pump

Abstract

The application discloses a magnetic suspension type centrifugal pump, wherein the rotation driving and axial position control of a rotor are completely independent and are respectively located at two sides of a rotor body, and the control logic is relatively simple; and the full suspension operation of the rotor can be realized through the magnetic force action between a dynamic magnetic ring and a static magnetic ring, so that the rotor and a volute (equivalent to a stator) are not in mechanical contact, heat generation and abrasion are reduced, and the possibility of thrombosis and the crushing damage to blood cells is maximally reduced; and the radial suspension limiting of the rotor can be realized by the dynamic magnetic ring and the static magnetic ring.

Description

Technical Field

[0001] This invention relates to the field of vibration reduction technology, and in particular to a magnetically levitated centrifugal pump. Background Technology

[0002] Heart failure (also known as ventricular assist device) is a condition where the heart is unable to pump enough blood to maintain the body's circulation. According to the World Health Organization (WHO), approximately 15% to 20% of people will experience heart failure to varying degrees. Over 50% of hospitalizations for heart failure occur in individuals over 65 years of age, and the five-year mortality rate exceeds 50%. For heart failure patients, there are only three treatment options: conservative drug therapy, heart transplantation, and ventricular assist devices (VADs). Drug therapy is less effective, and heart transplantation is extremely difficult due to donor availability. Therefore, VADs are recognized worldwide as the most effective treatment for various types of end-stage heart failure. The main component of a VAD is a blood pump. Generally, the inflow pipe of the blood pump is connected to the left or right ventricle of the human heart, and the outflow pipe is connected to the aorta or pulmonary artery. The pump is connected to a control driver (with a power supply device), which controls the blood pump to output blood with a certain pressure (generally ranging from 80 to 120 mmHg) and flow rate (generally ranging from 2 to 10 L / min) to share the power demand of the human heart for normal human activities.

[0003] Given the limitations of the operating environment for blood pumps, how to make blood pumps highly integrated and small in size while meeting functional requirements has always been a technical issue of concern to those skilled in the art. Summary of the Invention

[0004] The purpose of this invention is to provide a small-sized and compact magnetic levitation centrifugal pump.

[0005] This invention provides a magnetically levitated centrifugal pump, comprising a volute, a static magnetic ring, and a rotor;

[0006] 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.

[0007] The rotor includes a rotor body, a moving magnetic ring positioned on the rotor body, and at least two blades; the moving magnetic ring is coaxial with and nested with the stationary magnetic ring to limit the radial position of the rotor body and the volute.

[0008] The rotor body is fixed with a magnet assembly, which includes N first magnets arranged circumferentially, and the magnetic poles of all the first magnets are arranged alternately; the rotor body is also fixed with a magnetic component, which includes at least one of a magnetic ring and an iron core.

[0009] The volute encapsulates a drive coil assembly disposed opposite to the magnet assembly. The drive coil assembly cooperates with the magnet assembly to make the rotor body rotate circumferentially. The volute is fixed with a magnetic levitation coil assembly. When the magnetic levitation coil assembly is energized, the magnetic element and the magnetic levitation coil assembly generate an axial force.

[0010] Optionally, a position sensor may also be included for detecting the axial position of the rotor body;

[0011] Alternatively, or adjacent first magnets may be in close contact, or the magnet assembly may further include a transverse magnetic guide magnet located between two first magnets, with all the magnetic guide magnets and all the first magnets forming a Halbach magnet array.

[0012] Optionally, the magnet assembly and the magnetic element are respectively disposed at the first end and the second end of the rotor body, and the drive coil assembly and the magnetic levitation coil assembly are respectively disposed at the first end and the second end of the volute.

[0013] Optionally, the inner cavity of the volute has a first annular shell and a second annular shell, the first annular shell and the second annular shell being located at a first end and a second end of the volute, respectively. The first annular shell and the volute form a first sealed cavity for encapsulating the drive coil, and the second annular shell and the volute form a second sealed cavity for encapsulating the magnetic levitation coil assembly. The levitation cavity is formed between the first annular shell and the second annular shell. Both the first annular shell and the second annular shell are 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.

[0014] Optionally, the rotor body includes an annular body and a base body, which are fixedly connected along the axial direction, and there is a liquid outlet between the annular body and the base 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 blade is located between the annular body and the base body. The magnet assembly is encapsulated inside the annular body, and the moving magnetic ring and the magnetic component are encapsulated inside the base body.

[0015] Optionally, the base has an annular encapsulation cavity, the moving magnetic ring is sleeved on the inner ring wall of the annular encapsulation cavity, the magnetic component encapsulated in the base is located around the moving magnetic ring, and along the radial direction, the axial height of the middle region of the annular encapsulation cavity is greater than the axial height of the edge region.

[0016] Optionally, it also includes a base and a cover, the cover having a cylindrical tube open at one end and a flow guide cone connected to the other end of the cylindrical tube, the opening of the cylindrical tube being circumferentially sealed to the base, the static magnetic ring being fixed to the base by a threaded component and located inside the cylindrical tube, and the base being threadedly sealed to the volute and coaxial with the medium inlet, the flow guide cone passing through the central hole of the annular encapsulation cavity and protruding toward the medium inlet.

[0017] Optionally, a first auxiliary channel is formed between the outer peripheral surface and the outer end surface of the annular body and the corresponding inner wall of the volute; a second auxiliary channel is formed between the outer peripheral surface and the outer end surface of the annular encapsulation cavity and the corresponding inner wall of the volute, and between the inner peripheral wall of the annular encapsulation cavity and the cover; and the outer end surface of the annular body and the outer end surface of the base both have a predetermined angle with the horizontal plane, and the distance of the outer end surface from the horizontal plane increases from the outside to the inside.

[0018] Optionally, both the annular body and the seat body have a plurality of protrusions on their outer end faces. The protrusions extend from the inner edge to the outer edge, and the protrusions have a predetermined angle with the radial direction. The distance between adjacent protrusions is smaller as they approach the inner edge, or the height of the protrusions is lower as they approach the inner edge.

[0019] Optionally, the rotor is a centrifugal fully enclosed rotor structure, the blades are backward-curved blades, the magnet assembly and the magnetic element are respectively disposed at the first end and the second end of the rotor body, and the blades are located between the magnet assembly and the magnetic element;

[0020] Alternatively / and, the magnetic element includes a magnetic ring.

[0021] In this invention, the rotor's rotation drive and axial position control are completely independent and located on opposite sides of the rotor body, resulting in relatively simple control logic. Furthermore, the invention achieves full levitation of the rotor through the magnetic force between the moving and stationary magnetic rings. This eliminates mechanical contact between the rotor and the volute (equivalent to the stator), reducing heat generation, wear, and minimizing the possibility of thrombosis and crushing damage to blood cells. Radial levitation limiting of the rotor can be achieved using the moving and stationary magnetic rings. Attached Figure Description

[0022] Figure 1 This is a three-dimensional structural schematic diagram of a magnetically levitated centrifugal pump in one embodiment of the present invention;

[0023] Figure 2 A 3D cross-sectional view of a magnetically levitated centrifugal pump;

[0024] Figure 3 for Figure 1 A schematic diagram of the cross-sectional structure;

[0025] Figure 4 This is a schematic diagram of the rotor structure in one embodiment of the present invention;

[0026] Figure 5 for Figure 4 A schematic diagram showing another cross-sectional view of the rotor;

[0027] Figure 6 This is a schematic diagram of the rotor body in one embodiment of the present invention;

[0028] Figure 7 This is a schematic diagram of the rotor in another embodiment of the present invention;

[0029] Figure 8 This is a schematic diagram of the rotor in another embodiment of the present invention.

[0030] in, Figures 1 to 8 middle:

[0031] 100 Rotor; 11 Base; 111 Lower cover plate; 112 Annular sealing cavity; 113 Inner peripheral wall; 12 Ring body; 121 Upper cover plate; 1211 Outer end face; 1212 Protrusion; 13 Blade; 14 Magnet assembly; 15 Magnetic component; 16 Moving magnetic ring; 17 Magnetic element;

[0032] 200 Volute housing; 201 First volute housing; 202 Second volute housing; 203 First annular housing; 204 Second annular housing; 21 Drive coil assembly; 211 Drive 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;

[0033] 300 imported pipe;

[0034] 400 outlet pipe;

[0035] 1a First auxiliary flow channel; 1b Second auxiliary flow channel; 100a Liquid outlet. Detailed Implementation

[0036] In the description of this invention, it should be noted that the terms "left," "right," "upper," "lower," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the sake of simplicity in describing the technology, and do not indicate or imply that the device or element referred to must have a specific orientation, specific orientation structure, or operation, and therefore should not be construed as limiting the invention. Furthermore, the terms "first," "second," etc., are only for the convenience of describing two or more structures or components that are structurally and / or functionally the same or similar, and do not indicate any special limitation on the order and / or importance.

[0037] Without loss of generality, this article uses the application of a magnetic levitation centrifugal pump to heart pumping as an example to introduce the technical solution and its effects. Those skilled in the art should understand that although the magnetic levitation centrifugal pump described in this invention is based on the research of blood pumps, the magnetic levitation centrifugal pump in this article is not limited to heart pumping, and its application in other fields is still within the scope of protection of this article.

[0038] To enable those skilled in the art to better understand the technical solutions of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0039] Please refer to Figures 1 to 3 , Figure 1 This is a three-dimensional structural schematic diagram of a magnetically levitated centrifugal pump in one embodiment of the present invention; Figure 2 A 3D cross-sectional view of a magnetically levitated centrifugal pump; Figure 3 This is a schematic diagram of the cross-sectional structure shown in Figure 1.

[0040] This invention proposes a magnetically levitated centrifugal pump, comprising a volute, a static magnetic ring, and a rotor. The volute has a suspension cavity, a medium inlet, and a medium outlet, and the rotor is located inside the suspension cavity.

[0041] The volute can include a first volute 201 and a second volute 202, which together form the mounting space for the rotor. The first volute 201 and the second volute 202 can be detachably installed to facilitate the installation and maintenance of the rotor and other components. A medium inlet can be provided on the first volute 201, and a medium outlet can be formed 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 can all be made of titanium alloy.

[0042] Please refer to further information. Figure 4 and Figure 5 , Figure 4 This is a schematic diagram of the rotor structure in one embodiment of the present invention; Figure 5 for Figure 4A schematic diagram of the rotor from another perspective.

[0043] The rotor in this invention includes a rotor body, blades 13, a moving magnetic ring 16, magnetic components 17, and a magnet assembly 14.

[0044] The rotor body primarily provides the mounting foundation for other components of the rotor and facilitates assembly with the volute. A specific structure of the rotor body will be described later. The moving magnetic ring 16, blades 13, magnetic components 17, and magnet assembly 14 are all mounted on the rotor body. The number of blades 13 can be two or more, with a minimum of two. Each blade is circumferentially distributed. The blades 13 can be backward-curved. Backward-curved blades achieve optimized fluid efficiency, shear force, and streamline distribution. Under the same output flow rate and pressure requirements, the diameters of the rotor and volute can be smaller, and the requirements for motor speed and torque can be lower. This reduces the volume of the volute, rotor, and motor, enabling pump miniaturization under the same output capacity and minimizing the possibility of hemolysis and thrombosis.

[0045] The number of blades 13 can be determined according to the specific pump volume, and can usually be 3 to 7 blades. For example, in a specific example, the number of blades is 5.

[0046] Of course, blade 13 can also be a blade of equal thickness or a straight blade, as long as it meets the usage requirements.

[0047] A stationary magnetic ring 22 is mounted on the volute 200. The stationary magnetic ring 22 and the moving magnetic ring 16 are coaxial and nested to limit the radial position of the rotor 100 and the volute 200. Both the stationary magnetic ring 22 and the moving magnetic ring 16 may each consist of two or more annular magnets arranged axially. Figure 3 The diagram shows a specific example where both the stationary magnetic ring 22 and the moving magnetic ring 16 have three annular magnetic rings, with the moving magnetic ring 16 nested around the stationary magnetic ring 22. Of course, the number of annular magnetic rings in the stationary magnetic ring 22 and the moving magnetic ring 16 is not limited to those described herein and can be other values.

[0048] During operation, the principle by which the moving magnetic ring 16 and the stationary magnetic ring 22 define the radial position of the rotor relative to the volute 200 is as follows: the radial suspension of the rotor is achieved by the repulsive force between the moving and stationary magnetic rings. As mentioned above, a set of moving magnetic rings is installed on the rotor body; a set of stationary magnetic rings is installed on the volute; the moving and stationary magnetic rings together constitute a permanent magnet radial suspension bearing. The axial position of the stationary magnetic rings can be adjusted by the precision thread between the base 23 and the volute 200. Ideally, when the position of the stationary magnetic ring 22 is adjusted, and the rotor body is axially suspended in the middle of the volute suspension cavity, the axial positions of the stationary magnetic ring 22 and the moving magnetic ring 16 are exactly aligned; at this time, the radial stiffness of the permanent magnet radial suspension bearing formed by the moving magnetic ring 16 and the stationary magnetic ring 22 is at its maximum, while the axial force is 0.

[0049] The rotor body provided by this invention has a magnet assembly 14 fixed at its first end. The magnet assembly 14 includes N first magnets 141 arranged circumferentially, with the magnetic poles of all the first magnets 141 arranged alternately. Please refer to [reference needed]. Figure 4 In the magnet assembly, the first magnets are arranged in alternating N and S poles to form a complete circle. Each magnet in the magnet assembly 14 can be encapsulated inside the rotor body. In one example, the first magnets 141 can be tightly fitted together to form a full-pole arc magnetic ring, so that the disc motor formed by the drive coil assembly 21 mounted on the volute 200 can achieve a large motor efficiency.

[0050] Of course, the magnet assembly 14 may also include transverse magnetic guide magnets 18, which are located between the first magnets 141. That is, an equal number of mutually exclusive transverse magnetic guide magnets 18 are arranged between the first magnets 141 with staggered magnetic poles. For example, 10 sets of staggered first magnets and magnetic guide magnets form a Halbach magnet array (4-16 even sets are all possible, 10 sets are an optional scheme). This magnet array can achieve the effect of focusing magnets and increase the magnetic density between the air gaps of the motor with the same magnet volume, thereby further improving the motor efficiency.

[0051] Of course, the arrangement of the magnet assembly 14 is not limited to the method described in this article, and can also be in other ways, as long as the function described in this article can be achieved.

[0052] Correspondingly, the first end of the volute 200 corresponding to the rotor-mounted magnet assembly 14 is encapsulated with a drive coil assembly 21, wherein the drive coil assembly 21 may include a drive coil 211 and a working iron core 212. During operation, current flows through the drive coil 211 to generate a magnetic field, and the working iron core 212 amplifies the magnetic field generated by the drive coil 211. The first magnets 141, whose magnetic poles are arranged alternately on the magnet assembly 14 mounted on the rotor body, will generate a rotational force, driving the rotor body to rotate. The drive coil assembly 21 and the magnet assembly 14 installed inside the rotor body form a disc motor.

[0053] When the magnetic levitation coil assembly 27 is energized, the magnetic element 17 and the magnetic levitation coil assembly 27 generate an axial force, which is used to control the axial position of the rotor body. By adjusting the current direction of the magnetic levitation coil assembly 27, the direction of the force between the magnetic levitation coil assembly 271 and the magnetic element 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 can be obtained through a position sensor.

[0054] In this embodiment, the rotation drive and axial position control of the rotor are completely independent and located on opposite sides of the rotor body, resulting in relatively simple control logic. Furthermore, the invention achieves full suspension of the rotor through the magnetic force between the moving magnetic ring 16 and the stationary magnetic ring 22. This eliminates mechanical contact between the rotor 100 and the volute 200 (equivalent to the stator), reducing heat generation, wear, and minimizing the possibility of thrombosis and crushing damage to blood cells. The radial suspension limit of the rotor 100 can be achieved using the moving and stationary magnetic rings.

[0055] 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 located at the first end and the second end of the volute, respectively. The first annular shell 203 and the volute form a first sealed cavity for encapsulating the drive coil, and 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. Both the first annular shell 203 and the second annular shell 204 are 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.

[0056] Each annular shell can be fixed to the volute shell by bonding or other means.

[0057] Ceramic materials exhibit excellent biocompatibility with blood. Their hardness and insulating properties allow for a thinner annular shell and a closer fit of the drive coil to the inner wall, significantly reducing the air gap between the drive coil and the first magnet and completely eliminating eddy current losses. The first magnet can be arranged in a Halbach array, improving motor efficiency and achieving miniaturization of the blood pump while maintaining maximum output capacity. The insulating properties of ceramic also minimize the risk of leakage current from the drive coil to the blood flowing within the shell and eliminate the possibility of external electric field interference affecting the disc-type motor operation formed by the drive coil and first magnet assemblies. For example, the magnetically levitated centrifugal pump can still operate normally while the patient is receiving electric shock / rehabilitation / electrosurgical treatment.

[0058] In one example, the rotor body includes an annular body 12 and a base 11, which are axially fixedly connected. Each blade is located between the annular body 12 and the base 11. A liquid outlet is located between the annular body 12 and the base 11, and the liquid outlet can be located between two blades. The central through-hole of the annular body 12 connects to the liquid outlet 100a. Both the annular body 12 and the base 11 are internally encapsulated with magnetic steel assemblies, and a moving magnetic ring 16 is encapsulated inside the base 11. The annular body 12 and the base are axially fixedly connected, and a liquid outlet is located between them. The central through-hole of the annular body 12 connects 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 circumferentially. The specific number depends on the specific product and is not limited herein.

[0059] Specifically, the base has an annular encapsulation cavity, a moving magnetic ring is sleeved on the inner ring wall of the annular encapsulation cavity, and the magnetic component encapsulated in the base is located around the moving magnetic ring. In the radial direction, the axial height of the middle region of the annular encapsulation cavity is greater than the axial height of the edge region.

[0060] This minimizes the space occupied by the encapsulation cavity within the pump's internal fluid space, resulting in a more compact structure.

[0061] For ease of installation, the annular encapsulation cavity can be formed by providing an annular groove on the base body, with the lower cover plate 111 covering the opening of the annular groove to form a sealed chamber. Similarly, the sealed cavity for mounting the magnet assembly on the annular body can also be formed by providing an annular groove and the upper cover plate 121 for sealing.

[0062] The rotor in this 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 inlet channel. After being accelerated by the centrifugal blades of the rotor, it flows out through the outlet channel, injecting the blood into the aorta and providing pressure and flow for the whole body's blood circulation. The centrifugal blades of the rotor can be hollow.

[0063] In the above embodiments, the static magnetic ring can be installed inside the volute in the following ways.

[0064] In one example, the magnetically levitated centrifugal pump can further include a base and a housing 24 that is fastened to the base 23. The housing 24 is sealed and fixed to the base, and the static magnetic ring is fixed to the base by a threaded component, such as a screw, bolt, or threaded rod. The static magnetic ring is installed in the mounting space formed by the housing and the base. A mounting through-hole is provided at the second end of the volute, coaxial with the medium inlet. The base 23 is threaded and sealed to the mounting through-hole. The housing 24 includes a cylindrical tube 241 with one open end and a guide cone 242 connected to the other end of the cylindrical tube. The static magnetic ring 22 is located inside the cylindrical tube 241, and the guide cone 242 passes through the central hole of the housing 11 and protrudes towards the medium inlet. The guide cone 242 has a smaller radial dimension closer to the medium inlet, allowing the fluid at the medium inlet of the volute to flow uniformly circumferentially under the diversion of the guide cone, and thus uniformly enter between the blades.

[0065] In the above embodiment, the base and the volute are connected by a thread, which allows for precise adjustment of the axial position of the base relative to the volute so as to precisely match the moving magnetic ring on the rotor.

[0066] Please refer to Figure 6 and Figure 7 In the above embodiments, both the outer end face of the annular body 12 and the outer end face of the seat are provided with a plurality of protrusions 1212 (only the protrusions on the outer end face of the annular body are shown in the figure). The protrusions extend from the inner edge to the outer edge, and the protrusions 1212 have a predetermined angle with the radial direction. The distance between adjacent protrusions is smaller as they approach the inner edge. The protrusions 1212 have an internal spiral structure. In this way, a hydrodynamic hydraulic bearing is formed between the outer end face of the annular body and the first annular shell, and between the outer end face of the seat and the second annular shell. When the rotor is subjected to great axial disturbance and one end approaches the annular shell on that side, the hydrodynamic hydraulic bearing can provide additional restoring force towards the center, thereby improving the axial stability of the impeller.

[0067] Of course, the protrusion 1212 is lower in height closer to the inner edge, which can still achieve the above-mentioned technical effect, such as... Figure 7 As shown.

[0068] In one specific embodiment, a first auxiliary channel is formed between the outer peripheral surface and the outer end face of the annular body and the corresponding inner wall of the volute, and a second auxiliary channel is formed between the outer peripheral surface and the outer end face of the annular encapsulation cavity and the corresponding inner wall of the volute, and between the inner peripheral wall 113 of the annular encapsulation cavity and the cover 24.

[0069] During operation, the rotor is suspended and rotates at high speed in the middle of the volute 200. The blades between the annular body 12 and the seat 11 and the inner wall of the volute 200 form 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.

[0070] Meanwhile, a small portion of the blood entering the main flow channel inside the volute 200 flows back to the rotor body inlet through the first and second auxiliary channels, respectively, and then re-enters between the blades for acceleration before flowing into the volute. Through this design, all blood flowing through the centrifugal pump is unidirectional, with no stagnant or backflowing areas, thus minimizing the possibility of thrombosis.

[0071] Meanwhile, as mentioned above, since the annular shell, which is opposite to the end face of the annular body and the base body, is made of ceramic material, its surface is hard and smooth, reducing the possibility of damage to the surface of the annular shell when the rotor accidentally comes into contact with it. Because the motor efficiency is higher, under the same conditions, the thickness of the first magnet inside the rotor can be thinner, and the thickness of the outer end wall (cover plate) of the annular body 12 and the base body 11 is also correspondingly reduced, thereby reducing the length of the return flow channel inside the volute.

[0072] Simultaneously, both the outer end face of the annular body and the outer end face of the base have a predetermined angle with the horizontal plane. From the outside in, the distance between the outer end face and the horizontal plane increases, meaning that the outer end faces of the annular body and the base are concave inward. 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, while the inner gap is larger. This means that when blood passes through the area with the smaller outer gap, the shear force is relatively high, but the flow rate is fast and the transit time is short. When it passes through the area with the larger inner gap, the relative flow rate is low, but the shear force is also low. This minimizes the possibility of hemolysis and thrombosis. This allows for a relatively smaller gap in the auxiliary channel, reducing the backflow loss of the centrifugal pump and improving fluid efficiency. Under the same output flow / pressure requirements of the centrifugal pump, the diameter of the rotor and volute can be smaller, and the requirements for motor speed and torque can be lower, thereby reducing the volume of the volute / rotor and achieving miniaturization of the centrifugal pump under the same output capacity.

[0073] The aforementioned position sensor can be a Hall sensor or an eddy current sensor, as long as it can detect the axial position of the rotor body.

[0074] The present invention provides a detailed description of a magnetically levitated centrifugal pump. Specific examples have been used to illustrate the principles and implementation methods of the invention. These embodiments are merely illustrative and are intended to aid in understanding the method and core concepts of the invention. It should be noted that those skilled in the art can make various improvements and modifications to the invention without departing from its principles, and these improvements and modifications also fall within the scope of protection of the claims.

Claims

1. A magnetically levitated centrifugal pump, characterized in that, Includes the volute, the static magnetic ring, and the 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 includes a rotor body, a moving magnetic ring positioned on the rotor body, and at least two blades; the moving magnetic ring is coaxial with and nested with the stationary magnetic ring to limit the radial position of the rotor body and the volute. The rotor body is fixed with a magnet assembly, which includes N first magnets arranged circumferentially, and the magnetic poles of all the first magnets are arranged alternately; the rotor body is also fixed with a magnetic component, which includes at least one of a magnetic ring and an iron core. The volute encapsulates a drive coil assembly disposed opposite to the magnet assembly. The drive coil assembly cooperates with the magnet assembly to make the rotor body rotate circumferentially. The volute is fixed with a magnetic levitation coil assembly. When the magnetic levitation coil assembly is energized, the magnetic element and the magnetic levitation coil assembly generate an axial force. The inner cavity of the volute has a first annular shell and a second annular shell. The first annular shell and the second annular shell are located at the first end and the second end of the volute, respectively. The first annular shell and the volute form a first sealed cavity for encapsulating the drive coil assembly. 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. Both the first annular shell and the second annular shell are ceramic structures. The drive coil assembly is arranged against the first annular shell, and the magnetic levitation coil assembly is arranged against the second annular shell.

2. The magnetically levitated centrifugal pump as described in claim 1, characterized in that, It also includes a position sensor for detecting the axial position of the rotor body; Alternatively, or adjacent first magnets may be in close contact, or the magnet assembly may further include a transverse magnetic guide magnet located between two first magnets, with all the magnetic guide magnets and all the first magnets forming a Halbach magnet array.

3. The magnetically levitated centrifugal pump as described in claim 1, characterized in that, The magnet assembly and the magnetic component are respectively disposed at the first end and the second end of the rotor body, and the drive coil assembly and the magnetic levitation coil assembly are respectively disposed at the first end and the second end of the volute.

4. The magnetically levitated centrifugal pump as described in any one of claims 1 to 3, characterized in that, The rotor body includes an annular body and a base body, which are fixedly connected along the axial direction. There is a liquid outlet between the annular body and the base 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 blade is located between the annular body and the base body. The magnetic steel assembly is encapsulated inside the annular body. The moving magnetic ring and the magnetic component are encapsulated inside the base body.

5. The magnetically levitated centrifugal pump as described in claim 4, characterized in that, The base has an annular encapsulation cavity, the moving magnetic ring is sleeved on the inner ring wall of the annular encapsulation cavity, and the magnetic component encapsulated in the base is located around the moving magnetic ring in the radial direction. The axial height of the middle region of the annular encapsulation cavity is greater than the axial height of the edge region.

6. The magnetically levitated centrifugal pump as described in claim 5, characterized in that, It also includes a base and a cover, the cover having a cylindrical tube open at one end and a flow guide cone connected to the other end of the cylindrical tube. The opening of the cylindrical tube is circumferentially sealed to the base. The static magnetic ring is fixed to the base by a threaded component and located inside the cylindrical tube. The base is threadedly sealed to the volute and coaxial with the medium inlet. The flow guide cone passes through the central hole of the annular encapsulation cavity and protrudes toward the medium inlet.

7. The magnetically levitated centrifugal pump as described in claim 6, characterized in that, A first auxiliary channel is formed between the outer peripheral surface and the outer end surface of the annular body and the corresponding inner wall of the volute. A second auxiliary channel is formed between the outer peripheral surface and the outer end surface of the annular encapsulation cavity and the corresponding inner wall of the volute, and between the inner peripheral wall of the annular encapsulation cavity and the cover. The outer end surface of the annular body and the outer end surface of the base both have a predetermined angle with the horizontal plane. From the outside to the inside, the distance of the outer end surface from the horizontal plane increases.

8. The magnetically levitated centrifugal pump as described in claim 4, characterized in that, Both the annular body and the seat body have a number of protrusions on their outer end faces. The protrusions extend from the inner edge to the outer edge and have a predetermined angle with the radial direction. The distance between adjacent protrusions is smaller as they approach the inner edge, or the height of the protrusions is lower as they approach the inner edge.

9. The magnetically levitated centrifugal pump as described in claim 1 or 2, characterized in that, The rotor is a centrifugal fully enclosed rotor structure, the blades are backward-curved blades, the magnet assembly and the magnetic element are respectively disposed at the first end and the second end of the rotor body, and the blades are located between the magnet assembly and the magnetic element; Alternatively / and, the magnetic element includes a magnetic ring.

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