A radial permanent magnet suspension bearing

Abstract

This utility model discloses a radial permanent magnet suspension bearing, including a radial support structure. The radial support structure includes an outer permanent magnet ring and an inner permanent magnet ring placed inside the outer permanent magnet ring and coaxially arranged with it. The outer permanent magnet ring includes a first permanent magnet segment, a second permanent magnet segment, and a third permanent magnet segment arranged sequentially. The inner and outer diameters of the first and third permanent magnet segments have opposite polarities, and the inner diameters of the first and third permanent magnet segments also have opposite polarities. The inner permanent magnet ring includes a fourth, a fifth, and a sixth permanent magnet segment arranged sequentially. The inner and outer diameters of the fourth and sixth permanent magnet segments have opposite polarities, the outer diameter of the fourth permanent magnet segment has the same polarity as the inner diameter of the first permanent magnet segment, and the outer diameter of the sixth permanent magnet segment has the same polarity as the inner diameter of the third permanent magnet segment. The second and fifth permanent magnet segments have different polarities at their two ends, and the same polarity at the same ends of the second and fifth permanent magnet segments is the same. This design can improve the stability of the suspension support.

Description

Technical Field

[0001] This utility model belongs to the technical field of cardiac assist devices, specifically relating to a radial permanent magnet suspension bearing. Background Technology

[0002] Patent application number 202311849700.3 discloses a "dual-heart assisted centrifugal blood pump", which includes a pump housing assembly, a rotor assembly, a support mechanism, and a drive mechanism. The pump housing assembly has a pump housing body, a partition plate disposed on the pump housing body and dividing it into two pump chambers, and two sets of pipe assemblies respectively communicating with the two pump chambers. The rotor assembly has a rotor passing through the two pump chambers and an inlet pipe, and two impellers sleeved on the outside of the rotor, with the two impellers respectively placed in the two pump chambers. The support mechanism has two sets of radial support mechanisms spaced apart on the rotor and an axial support mechanism disposed between the two impellers. The radial support mechanism and the axial support mechanism work together to keep the rotor assembly in a stable suspended state. The drive mechanism can drive the rotor assembly to rotate, so that the two impellers drive the blood circulation flow in the two pump chambers respectively.

[0003] The magnetic levitation dual-center auxiliary device requires radial levitation support and axial levitation support. The existing radial levitation support adopts a structure of multiple sets of external magnetic components and internal magnetic columns. The internal magnetic columns are made of strong permanent magnet material and are axially magnetized, belonging to the rotor part of the magnetic bearing. Multiple sets of external magnetic components are symmetrically distributed around the internal magnetic columns, belonging to the stator part of the magnetic bearing. The permanent magnet cores of the external magnetic components have the same magnetic poles facing the internal magnetic columns. Relying on this static magnetic repulsion, the internal magnetic columns can be passively levited radially to a certain extent.

[0004] However, the stability of the radial support in this structure still needs to be improved. Utility Model Content

[0005] To address the problem of low stability in existing radial suspension supports, this invention proposes a radial permanent magnet suspension bearing.

[0006] The objective of this utility model is achieved through the following technical solution:

[0007] This utility model discloses a radial permanent magnet suspension bearing, including a radial support structure. The radial support structure includes an outer permanent magnet ring and an inner permanent magnet ring placed inside the outer permanent magnet ring and coaxially arranged with the outer permanent magnet ring.

[0008] The outer permanent magnet ring includes a first permanent magnet segment, a second permanent magnet segment, and a third permanent magnet segment arranged sequentially. The inner and outer diameters of the first and third permanent magnet segments have opposite polarities, and the inner diameters of the first and third permanent magnet segments also have opposite polarities.

[0009] The inner permanent magnet ring includes a fourth permanent magnet segment, a fifth permanent magnet segment, and a sixth permanent magnet segment arranged sequentially. The inner and outer diameters of the fourth and sixth permanent magnet segments have opposite polarities. The polarity of the outer diameter of the fourth permanent magnet segment is the same as the polarity of the inner diameter of the first permanent magnet segment, and the polarity of the outer diameter of the sixth permanent magnet segment is the same as the polarity of the inner diameter of the third permanent magnet segment.

[0010] The polarities at both ends of the second permanent magnet segment and the fifth permanent magnet segment are different, and the polarities at the same ends of the second permanent magnet segment and the fifth permanent magnet segment are the same.

[0011] The beneficial effects of this utility model are:

[0012] The radial support structure in this scheme has two permanent magnet rings that are radially magnetized, with one polarity on the inner and one on the outer side. The second permanent magnet ring in the middle is axially magnetized. The three magnetic rings, which are stacked together, appear to be attached to each other on the same magnetic poles from the inside. The radial magnetic fields of the outer and inner permanent magnet rings are all opposite to each other, and they generate radial repulsion by repulsion, which can improve the stability of the suspension support. Attached Figure Description

[0013] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0014] Figure 1 This is a schematic diagram of the structure of the magnetic levitation dual-center auxiliary device of this utility model;

[0015] Figure 2 This is a schematic diagram of the pump body.

[0016] Figure 3 This is a schematic diagram of the rotor assembly.

[0017] Figure 4 This is a schematic diagram of the axially limiting sliding bearing.

[0018] Figure 5 This is a schematic diagram of an internal sliding head.

[0019] Figure 6 A schematic diagram showing the state of the axially limited sliding bearing achieving the upper movement limit;

[0020] Figure 7 This is a schematic diagram of a radial support structure;

[0021] Figure 8 A schematic diagram of the main pump chamber;

[0022] Figure 9 This is a schematic diagram of the axial support structure;

[0023] Figure 10 This is a force analysis diagram of the rotor assembly;

[0024] Figure 11 This is a schematic diagram of the dual-center auxiliary device for magnetic levitation of this utility model.

[0025] Figure 12 This is a schematic diagram of the single-center auxiliary function of the magnetic levitation dual-center auxiliary device of this utility model.

[0026] The attached figures are labeled as follows:

[0027] 1-Pump body; 111-Inner pipe; 112-Outer pipe; 12-Main pump chamber; 121-Main pump outlet pipe; 13-Connecting hole; 131-Fixing groove; 14-Auxiliary pump chamber; 141-Outer inlet pipe; 142-Auxiliary pump outlet pipe; 15-Bridging cavity; 16-Pour-in hole; 17-Lead-in hole; 18-Annular plate;

[0028] 2-Rotor assembly; 21-Shaft; 22-Connecting rod; 231-Main upper cover; 232-Main blade; 241-Secondary upper cover; 242-Secondary blade;

[0029] 3-Radial support structure; 31-First permanent magnet segment; 32-Second permanent magnet segment; 33-Third permanent magnet segment; 34-Fourth permanent magnet segment; 35-Fifth permanent magnet segment; 36-Sixth permanent magnet segment;

[0030] 4-Axial support structure; 41-Sensor; 42-Iron core; 43-First winding; 44-Second winding;

[0031] 5-Axial limiting sliding bearing; 51-Inner sliding head; 511-Cut structure; 52-Upper limit ring; 521-Second cut structure; 53-Lower limit ring; 531-Third cut structure;

[0032] 61-Regulating valve; 62-First connecting pipe; 63-Second connecting pipe; 64-Third connecting pipe; 65-Second regulating valve;

[0033] 7-Electrical control system;

[0034] 8-Infusion system. Detailed Implementation

[0035] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, not all embodiments. The components of the embodiments of this utility model described and shown in the accompanying drawings can typically be arranged and designed in various different configurations.

[0036] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0037] It should be noted that, where there is no conflict, the embodiments and features in the embodiments of this utility model can be combined with each other.

[0038] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0039] In the description of this utility model, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product of this utility model is in use, or the orientation or positional relationship commonly understood by those skilled in the art. They are only used for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model. In addition, the terms "first," "second," etc., are only used to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0040] In the description of this utility model, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0041] This utility model provides a magnetic levitation dual-center auxiliary device, including a pump body 1, a rotor assembly 2, a support assembly and a drive assembly.

[0042] Among them, reference Figure 1 , 2 As shown, the pump body 1 includes a main pump inlet pipe, a main pump chamber 12, a connecting hole 13, and a secondary pump chamber 14 connected in sequence. The main pump inlet pipe includes an inner pipe 111 and an outer pipe 112 placed outside the inner pipe. The main pump chamber 12 is connected to a main pump outlet pipe 121. The secondary pump chamber 14 is connected to an outer inlet pipe 141 and a secondary pump outlet pipe 142. The connecting hole 13 is surrounded by a partition 15 and a filling hole 16 connected to the connecting hole 13.

[0043] Reference Figure 1 , 3 As shown, the rotor assembly 2 includes a shaft 21 with one end placed inside the inner tube 111, a first impeller assembly placed in the main pump chamber 12, a connecting rod 22 placed in the connecting hole 13, and a second impeller assembly placed in the auxiliary pump chamber 14, which are connected in sequence.

[0044] Reference Figure 1 As shown, the support assembly includes a radial support structure disposed on the inner tube 111 and the shaft 21 and acting on the shaft 21 to achieve radial support of the rotor assembly, and an axial support structure disposed in the cavity 15 and acting on the second impeller assembly to achieve axial support of the rotor assembly.

[0045] Reference Figure 1 As shown, the drive assembly is used to drive the rotor assembly 2 to rotate and is disposed within the cavity 15.

[0046] With the above structure, a single drive assembly and rotor assembly simultaneously drive the blood in the two pump chambers to circulate, thereby effectively realizing the dual-heart assist function and avoiding the drawbacks of existing implanted blood pumps.

[0047] With the above structure, the drive assembly is located between the main pump chamber and the auxiliary pump chamber, and the radial support structure is only located on the main pump inlet pipe. This not only reduces the length of the main pump inlet pipe and improves the success rate of the operation, but also achieves a dual flow channel by using an inner pipe 111 and an outer pipe structure. The radial support structure is located on both sides of the inner flow channel formed by the inner pipe 111 and the shaft 21. The radial air gap between the inner and outer magnetic fields can be very small, while the gap in the outer flow channel is large. This provides sufficient pump inlet cross-sectional area for the high-efficiency design of the pump fluid, keeps the channel smooth, and reduces resistance.

[0048] By adopting the above structure, the drive component is placed in the cavity, separated from the radial support structure and with sufficient spacing. This not only does not affect the pump's fluid efficiency, but also eliminates the mutual interference between the magnetic levitation device and the motor, which is beneficial to improving the mechanical efficiency, stability and safety of the blood pump.

[0049] With the above structure, the cavity volume is large, providing sufficient space for the drive components, which further increases the power of the drive components, meets the required mechanical power consumption, and improves efficiency.

[0050] The radial support structure is part of the radial permanent magnet levitation bearing in this scheme.

[0051] Specifically, there are many ways to implement the first and second impeller groups of rotor assembly 2. For example, the structure disclosed in patent application number 202311849700.3, a "dual-heart assisted centrifugal blood pump," is used, where both the upper and lower ends of the blades are closed and covered. However, with the above structure, the impellers are subjected to a large passive axial upward hydraulic thrust. Therefore, preferably, rotor assembly 2 adopts the following... Figure 3 The structure shown is such that the first impeller assembly includes a main upper cover 231 and main blades 232, and the second impeller assembly includes a secondary upper cover 241 and secondary blades 242. With this structure, the lower ends of the first and second impeller assemblies are open and without covers, which can reduce the passive axial upward hydraulic thrust experienced by the two impeller assemblies.

[0052] The rotor assembly 2 structure described above, i.e., the single-sided open design, can be used to generate hydrodynamic pressure in a single direction along the axial direction. Figure 1 The direction shown is downward, which is used to counteract the large attraction of the stator core to the rotor magnet. The electromagnet can also determine the axial position of the impeller and the direction and magnitude of the axial force at any time through the detection of the sensor. As needed, it can generate an axial force in a different direction to balance the axial force, so that the dynamic axial resultant force is zero or approaches zero, achieving a steady-state axial suspension effect.

[0053] The main cover 231 and the secondary cover 241 are coaxial and parallel to each other.

[0054] Further, in the above structure, such as Figure 8As shown, an annular plate 18 is disposed within the main pump chamber 12. The annular plate 18 is positioned between the main blade 232 and the bottom of the main pump chamber 12, and the distance between the annular plate 18 and the bottom of the main pump chamber 12 gradually increases from the outer diameter to the inner diameter. That is, the annular plate 18 has an overall concave structure, forming a backflow channel with the bottom of the main pump chamber 12. The inlet of the backflow channel is the gap between the annular plate 18 and the side wall of the main pump chamber 12, and the outlet of the backflow channel is the gap between the annular plate 18 and the rotor assembly 2. The pressure at the inlet of the backflow channel is greater than the pressure at the outlet of the middle backflow channel. The secondary backflow driven by the pressure difference can effectively flush the sliding bearing opening, preventing thrombosis.

[0055] In a further embodiment of the above structure, the outer diameter of the main blade 232 is larger than the outer diameter of the auxiliary blade 242. The large outer diameter of the main blade 232 is to maintain the requirement of high fluid efficiency, while the small outer diameter of the auxiliary blade 242 ensures that the auxiliary pump pressure is always kept below 30 mmHg, but the auxiliary flow rate can be ensured to avoid pulmonary hypertension during right ventricular assist.

[0056] In a further embodiment of the above structure, the drive assembly includes a magnet to establish and maintain a magnetic field, and the main upper cover 231 can be directly used as the magnet of the drive assembly. In this case, the main upper cover 231 adopts a strong permanent magnet material of type 52-58 neodymium iron boron.

[0057] In order to increase the component and energy density of the built-in rotor magnets to improve the efficiency of the motor, increase the axial downward hydraulic pressure and the axial suspension performance of the rotor impeller, the outer diameter of the main upper cover 231 is smaller than the outer diameter of the secondary upper cover 241.

[0058] Axial support structure 4 achieves axial suspension balance of rotor assembly 2, such as Figure 9 As shown, it includes a sensor 41 for detecting the axial movement of the rotor assembly 2, a plurality of iron cores 42 evenly distributed around the connecting rod 22, and a first winding 43 wound on the iron cores 42.

[0059] The sensor can be implemented as a position sensor, distance sensor, etc.

[0060] The iron core 42 has 6 cores, and one end of each core is plate-shaped.

[0061] In order to simultaneously achieve stable detection of rotor assembly 2, there are multiple sensors 41, which are evenly distributed around the connecting rod 22.

[0062] There are many ways to implement the drive component. In order to simplify the structure, the drive component and the axial support structure 4 share some components. That is, the drive component includes a second winding 44 wound on the iron core 42, that is, they share the iron core 42.

[0063] Using the aforementioned axial support structure 4 and drive structure, during operation, the main upper cover 231 and the upper surface of the main pump chamber 12 form the main return flow channel, and the auxiliary upper cover 241 and the upper surface of the auxiliary pump chamber 14 form the auxiliary return flow channel. Both channels will experience backflow due to pressure difference, generating two hydraulic pressures: the main hydraulic pressure F2 and the auxiliary hydraulic pressure F3. These two forces are axially downwards, and their magnitudes are positively correlated with the impeller speed and the pump pressure. During high-speed operation, the entire device is affected by multiple axial forces, which can be categorized into weak and strong axial forces. Weak axial forces mainly include the axial component of the rotor assembly's gravity, the liquid impingement force of the main pump inlet pipe, the liquid buoyancy force of the impeller assembly, and the axial force generated by the slight offset of the radial magnetic levitation assembly. These are weak influencing factors and can be disregarded in the analysis. Figure 10 As shown, the strong axial force mainly includes four axial forces: magnetic attraction F1, main hydraulic pressure F2, auxiliary hydraulic pressure F3, and active electromagnetic force F4. F1 is the attraction force generated by the rotor magnets on the stator core 42, with the force direction being axially upward. The magnitude of the force is positively correlated with the mass and distance between the two forces. Since the outer circumferential pressure of the main blade 232 is 5-10 times higher than that of the auxiliary blade 242, F2 is much larger than F3. Because the upward axial force F1 is relatively large, while the downward hydraulic pressures F1 and F2 vary significantly due to the uncertain rotational speed, the combined force of F2 and F3 is insufficient to counteract F1 when the rotor assembly operates at low speeds. When the rotor assembly experiences a slight axial displacement, including upward displacement of the impeller at low speeds and upward / downward displacement due to impact, the sensor will detect the position of the rotor assembly. After signal amplification, feedback, and control, an active electromagnetic force F4 will be generated to pull the rotor impeller back to the equilibrium position. The combined force of F2, F3, and F4 is sufficient to balance F1, keeping the total axial force zero, so that the rotor assembly is always in an axially suspended state.

[0064] Generally, the assembly consisting of the iron core 42, the first winding 43, and the second winding 44 is arranged in 6 groups, and the power supply connection can be divided into two groups of 3+3. During normal operation, the active electromagnetic force F4 is an auxiliary force, and its value should not be too large. The direction can be downward or upward, and it can generally work intermittently, with low power consumption and heat generation.

[0065] Under the action of the support components, the rotor assembly maintains a suspended and balanced state. To protect the rotor assembly and prevent damage during startup, sudden changes, and emergency situations, an axially limiting sliding bearing 5 is also included. Figures 4 to 6 As shown, the axial limiting sliding bearing includes an upper limiting ring 52 and a lower limiting ring 53, both fixed on the communicating hole 13, and an inner sliding head 51 fixed on the connecting rod 22 and placed between the upper limiting ring 52 and the lower limiting ring 53.

[0066] Both ends of the inner sliding head 51 are provided with a first slicing structure 511. The upper limit ring 52 and the lower limit ring 53 are respectively provided with a second slicing structure 521 and a third slicing structure 531 parallel to the first slicing structure 511 at the corresponding positions of the first slicing structure 511. The injection hole 16 is provided between the second slicing structure 521 and the third slicing structure 531.

[0067] To enhance the stability of the upper limit ring 52 and the lower limit ring 53, a fixing groove can be provided on the side wall of the connecting hole to achieve the installation and fixing of the limit rings.

[0068] During normal operation, there are gaps between the first sectional structure of the inner sliding head 51 and the second sectional structure 521 and the third sectional structure 531, so they do not contact each other. The rotor assembly is in a suspended state and will not wear. The injection system 8 can provide anticoagulant for lubrication through the injection hole 16.

[0069] When the rotor assembly moves up and down, the amount of vertical movement can be limited to prevent the rotor assembly from impacting or scraping against the pump chamber, thus avoiding safety accidents and complications such as thrombosis and hemolysis. In addition to upper and lower limits, radial limits can also be implemented to prevent mechanical wear and damage caused by malfunctions or accidents.

[0070] The inner sliding head 51 can be made of hard materials such as diamond, silicon carbide, silicon nitride, or boron carbide; the upper limit ring 52 and the lower limit ring 53 can be made of alumina, zirconium oxide, or yttrium zirconium oxide composite ceramic materials.

[0071] There are many ways to implement the radial support structure 3. For example, the structure disclosed in patent application number 202311849700.3 is from a "dual-heart assisted centrifugal blood pump". To improve the stability of the radial support, it is preferable to adopt a structure such as... Figure 7 The structure shown, namely the radial support structure 3, includes an outer permanent magnet ring disposed on the inner tube 111 and an inner permanent magnet ring disposed on the shaft 21;

[0072] The outer permanent magnet ring includes a first permanent magnet segment 31, a second permanent magnet segment 32, and a third permanent magnet segment 33 arranged sequentially. The inner and outer diameters of the first permanent magnet segment 31 and the third permanent magnet segment 33 have opposite polarities, and the inner diameters of the first permanent magnet segment 31 and the third permanent magnet segment 33 have opposite polarities.

[0073] The inner permanent magnet ring includes a fourth permanent magnet segment 34, a fifth permanent magnet segment 35, and a sixth permanent magnet segment 36 arranged sequentially. The inner and outer diameters of the fourth permanent magnet segment 34 and the sixth permanent magnet segment 36 have opposite polarities. The polarity of the outer diameter of the fourth permanent magnet segment 34 is the same as the polarity of the inner diameter of the first permanent magnet segment 31. The polarity of the outer diameter of the sixth permanent magnet segment 36 is the same as the polarity of the inner diameter of the third permanent magnet segment 33.

[0074] The polarities of the two ends of the second permanent magnet segment 32 and the fifth permanent magnet segment 35 are different, and the polarities of the same ends of the second permanent magnet segment 32 and the fifth permanent magnet segment 35 are the same.

[0075] Using the above structure, the outer permanent magnet ring includes a first permanent magnet segment 31, a second permanent magnet segment 32, and a third permanent magnet segment 33 arranged sequentially. The upper and lower permanent magnet segments form radial magnetization, with one polarity in the radial direction (inner and outer). The second permanent magnet segment 32 is axially magnetized, meaning its two ends have different polarities. When the upper, middle, and lower magnetic rings are stacked together, they appear to be in contact with each other on the same magnetic poles from the inside. The inner permanent magnet ring includes a fourth permanent magnet segment 34, a fifth permanent magnet segment 35, and a sixth permanent magnet segment 36 arranged sequentially. The upper and lower permanent magnet segments form radial magnetization, with one polarity in the radial direction (inner and outer). The fifth permanent magnet segment 35 is axially magnetized. When the upper, middle, and lower magnetic rings are stacked together, they appear to be in contact with each other on the same magnetic poles from the outside. The radial magnetic fields of the outer and inner permanent magnet rings are all opposite each other, generating radial repulsion through repulsion. When axial alignment is maintained, the inner and outer magnetic groups can achieve radial magnetic levitation.

[0076] To further improve radial stability, the radial support structure 3 has two sets, and the two sets of radial support structures 3 are coaxially arranged.

[0077] When installing the two sets of radial support structures 3 at the main pump inlet pipe, they should be spaced as far apart as possible. This is to avoid magnetic interference and to ensure more stable radial levitation. Since two points determine a line, if the two sets of radial support structures 3 are too close, the rotor's radial direction may easily deflect. Installing the two sets of radial support structures 3 with a distance between them also makes the rotor impeller's center of gravity more stable, resulting in better radial levitation. Coaxially aligning the two sets of radial support structures 3 allows the rotor assembly to maintain radial magnetic levitation. Combined with the gyroscopic axis-fixing effect during rotation, this achieves a good radial levitation effect. Considering both the length of the main pump inlet pipe and radial stability, the preferred distance between the two sets of radial support structures 3 is greater than or equal to 10 mm and less than 15 mm.

[0078] For example, if the axial direction of the shaft is defined as the up-down direction, such as... Figure 4As shown, the outer diameter surface of the first permanent magnet segment 31 has an S pole polarity, and the inner diameter surface has an N pole polarity; the upper and lower ends of the second permanent magnet segment 32 have N and S pole polarities, respectively; the outer diameter surface of the third permanent magnet segment 33 has an N pole polarity, and the inner diameter surface has an S pole polarity; the outer diameter surface of the fourth permanent magnet segment 34 has an N pole polarity, and the inner diameter surface has an S pole polarity; the upper and lower ends of the fifth permanent magnet segment 35 have N and S pole polarities, respectively; and the outer diameter surface of the sixth permanent magnet segment 36 has an S pole polarity, and the inner diameter surface has an N pole polarity. This arrangement allows the relative positions of the outer and inner permanent magnet rings to generate combined and enhanced N and S poles, with radially similar magnetic poles facing each other. Due to magnetic short circuits at the outer diameter surface of the outer permanent magnet ring and the center of the inner permanent magnet ring, the magnetism is extremely weak. This arrangement can significantly improve the energy density and magnetic levitation effect of permanent magnet levitation.

[0079] The polarities of the two sets of radial support structures 3 are symmetrically arranged with respect to their perpendicular bisectors, meaning that one set of radial support structures 3 is formed by flipping and inverting the other set. The same magnetic poles of the two sets of radial support structures 3 are opposite each other, and the distance between them also minimizes their mutual magnetic interference.

[0080] The radial support structure 3 uses a strong permanent magnet material of type 52-58 neodymium iron boron.

[0081] An external perfusion system delivers heparin-based anticoagulant solution into the cavity of pump body 1 through perfusion port 16. A lead hole can be provided on pump body 1 for connecting the delivery pipe of the perfusion system and the control line of the axial support structure 4 and drive assembly. The heparin-based anticoagulant solution delivered by the perfusion system can flush the bearing port of the axial limiting sliding bearing through perfusion port 16, thus providing a dynamic seal for the bearing. The anticoagulant solution can prevent blood clotting and thrombus formation; the perfusion solution can also lubricate the bearing.

[0082] The external perfusion system 8 delivers heparin-based anticoagulants, which have an anticoagulant effect, especially in small gaps and dead spaces, such as the fit gaps of mechanical bearings, effectively preventing thrombosis and even embolism. Furthermore, the internal pressure perfusion and flushing of the bearing's confined space acts as a dynamic seal at the bearing opening, preventing blood intrusion and avoiding thrombosis and hemolysis caused by mechanical abrasion. The anticoagulant also lubricates the bearing, extending the mechanical lifespan of both the bearing and the blood pump. The perfusion system has alarm prompts, requiring patients to replenish anticoagulants promptly as instructed; patients do not need to take oral anticoagulants, and there is no need to worry about thrombosis within the blood pump due to forgotten or missed doses.

[0083] The magnetic levitation dual-heart auxiliary device described above not only has dual-heart auxiliary function, but also allows for the installation of only the main pump, with the left heart being assisted by the main pump chamber 12.

[0084] For patients with dual heart failure, refer to Figure 11Through open-chest surgery, a magnetically levitated dual-heart assist device is installed in the patient's chest cavity. The main pump inlet tube is directly inserted into the left ventricle and secured with a suture ring. The main pump outlet tube 121 is connected to a first connecting tube 62, which connects to the aortic opening. A first regulating valve 61 on the first connecting tube regulates the flow rate. The external inlet tube 141 is connected to a second connecting tube 63, which is inserted into the right ventricle. The auxiliary pump outlet tube 142 is connected to a third connecting tube 64, which connects to the pulmonary artery opening. A second regulating valve 65 on the third connecting tube 64 regulates the flow rate. The signal wire of the winding coil is led out of the patient's body through a lead hole and connected to an external electrical control system 7. Driven by a motor, the system drives the rotor assembly, using centrifugal force to promote the circulation of blood in both the systemic and pulmonary systems, thus providing dual-heart assistance.

[0085] This structure allows for the immediate shutdown of one blood pump. If, due to the recovery of function in one ventricle, the doctor decides to reduce its auxiliary flow rate to a very low level or even shut it off, this can be done via external electrical control. If the left ventricle recovers, adjusting the first regulating valve 61 decreases the main pump outlet diameter, reducing the flow rate; shutting it off completely shuts off the flow. If the right ventricle recovers, adjusting the second regulating valve 65 decreases the auxiliary pump outlet diameter, reducing the flow rate; shutting it off completely shuts off the flow. However, it is generally not recommended to completely shut off the valves; leaving a small diameter and adjusting the flow rate to a very low level is sufficient. The motor continues to rotate, maintaining the necessary flow assistance to the other failing ventricle. Due to the infusion of anticoagulant, intrapump coagulation and thrombosis will not occur inside the shut-off auxiliary pump or at the connected ventricular inlet. When the patient experiences heart failure again and needs to restart the auxiliary function of the shut-off pump, simply increasing the outlet regulating valve is sufficient; the operation is extremely convenient. Because of the regulating valves, left and right ventricular auxiliary pumps work well together, and the flow rate matching is adjustable.

[0086] When only the main pump is installed, such as Figure 12 As shown, the installation method of the main pump inlet pipe and main pump outlet pipe 121 is the same as that for patients with dual heart failure. The difference is that a connecting pipe is used to directly connect the external inlet pipe 141 and the auxiliary pump outlet pipe 142. This is equivalent to eliminating the auxiliary function of the auxiliary pump chamber. Although the second impeller assembly is still rotating, it is only the anticoagulant fluid filled in the pump that is circulating on its own, so there is no need to worry about complications such as thrombosis.

[0087] With the above structure, the main upper cover 231, i.e. the magnet, is located inside the auxiliary pump chamber. Since the auxiliary pump chamber has a sufficiently large and ample space, the rotor magnet can be designed to be large enough according to the motor design requirements, and the magnetic air gap can be very small. This not only improves the efficiency of the motor but also does not affect the fluid efficiency of the auxiliary pump. Because the motor has high power conversion efficiency and low heat generation, the damage to blood cells and complications such as thermal hemolysis are reduced, thus improving the safety of the blood pump.

[0088] The structure of this design allows for dual-cardiac support with a single pump, or operation with only one pump, such as for left ventricular support. This facilitates clinical surgical implantation and reduces the manufacturing and sales costs of the pump. Its novel, rational, and simple structure significantly improves the usability of the pump; the small pump volume and light weight reduce the invasiveness of implantation.

[0089] Those skilled in the art will recognize that the embodiments described herein are intended to help the reader understand the principles of this invention, and should be understood that the scope of protection of this invention is not limited to such specific statements and embodiments. Those skilled in the art can make various other specific modifications and combinations based on these technical teachings disclosed in this invention without departing from the essence of this invention, and these modifications and combinations are still within the scope of protection of this invention.

Claims

1. A radial permanent magnet levitation bearing, comprising a radial support structure (3), characterized in that, The radial support structure (3) includes an outer permanent magnet ring and an inner permanent magnet ring placed inside the outer permanent magnet ring and coaxially arranged with the outer permanent magnet ring; The outer permanent magnet ring includes a first permanent magnet segment (31), a second permanent magnet segment (32), and a third permanent magnet segment (33) arranged sequentially. The inner and outer diameters of the first permanent magnet segment (31) and the third permanent magnet segment (33) have opposite polarities, and the inner diameters of the first permanent magnet segment (31) and the third permanent magnet segment (33) have opposite polarities. The inner permanent magnet ring includes a fourth permanent magnet segment (34), a fifth permanent magnet segment (35), and a sixth permanent magnet segment (36) arranged sequentially. The inner and outer diameters of the fourth permanent magnet segment (34) and the sixth permanent magnet segment (36) have opposite polarities. The polarity of the outer diameter of the fourth permanent magnet segment (34) is the same as the polarity of the inner diameter of the first permanent magnet segment (31), and the polarity of the outer diameter of the sixth permanent magnet segment (36) is the same as the polarity of the inner diameter of the third permanent magnet segment (33). The polarities of the two ends of the second permanent magnet segment (32) and the fifth permanent magnet segment (35) are different, and the polarities of the same ends of the second permanent magnet segment (32) and the fifth permanent magnet segment (35) are the same.

2. The radial permanent magnet levitation bearing according to claim 1, characterized in that, The radial support structure (3) has two sets, and the two sets of radial support structures (3) are coaxially arranged.

3. A radial permanent magnet levitation bearing according to claim 2, characterized in that, The polarities of the two sets of radial support structures (3) are symmetrically arranged with respect to their perpendicular lines.

4. A radial permanent magnet levitation bearing according to claim 3, characterized in that, The polarity of the outer diameter surface of the first permanent magnet segment (31) of the first radial support structure (3) is S pole, and the polarity of the inner diameter surface is N pole. The polarities of the upper and lower ends of the second permanent magnet segment (32) are N pole and S pole, respectively. The first permanent magnet segment (31) of the second radial support structure (3) is adjacent to the third permanent magnet segment (33) of the first radial support structure (3). The polarity of the outer diameter surface of the first permanent magnet segment (31) of the second radial support structure (3) is N pole, and the polarity of the inner diameter surface is S pole. The polarities of the upper and lower ends of the second permanent magnet segment (32) are S pole and N pole, respectively.

5. A radial permanent magnet levitation bearing according to claim 1, characterized in that, The radial support structure (3) is provided in only one set, and the polarity of the outer diameter surface of the first permanent magnet segment (31) is S pole and the polarity of the inner diameter surface is N pole. The polarities of the upper and lower ends of the second permanent magnet segment (32) are N pole and S pole, respectively.

6. A radial permanent magnet levitation bearing according to claim 1, characterized in that, It also includes an inner tube (111) for fixing the outer permanent magnet ring, a shaft (21) for fixing the inner permanent magnet ring, and an outer tube (112) sleeved outside the inner tube (111).

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