Axial limit sliding bearing

Abstract

The utility model discloses an axial position limiting sliding bearing, including the upper limit ring and the lower limit ring of the communication hole of even fixed in the pump body, the inner sliding head for being fixed on the connecting rod and being placed between the upper limit ring and the lower limit ring. The utility model adopts the upper limit ring and the lower limit ring to realize the upper and lower movement limit of rotor assembly, and the upper limit ring and the lower limit ring have a certain distance, and the distance is convenient for the perfusion port design of perfusion anticoagulation system.

Description

Technical Field

[0001] This utility model belongs to the technical field of cardiac assist devices, specifically relating to an axial limiting sliding bearing. Background Technology

[0002] For patients with advanced heart failure, there are currently no effective medical treatments; only heart transplantation and artificial hearts are highly effective surgical options. However, due to a severe shortage of donors, heart transplantation has become a symbolic treatment, thus artificial hearts have become a source of great hope.

[0003] Artificial hearts and cardiac assist devices can both be simply referred to as "blood pumps." Artificial hearts can be classified according to function into total artificial hearts and assistive artificial hearts. In recent years, cardiac assist devices, represented by centrifugal or axial flow blood pumps with blades, have become the mainstream in the development of artificial hearts. However, these devices require the installation of two blood pumps, resulting in a large implantation size and significant invasiveness. Furthermore, the external controller and battery also require two systems, leading to a poor quality of life for patients. Therefore, there is an urgent clinical need for blood pumps with dual cardiac assist functions that are also compact.

[0004] 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 comprises a main body, a partition separating the main body into two pump chambers, and two sets of pipe assemblies communicating with the two pump chambers respectively. The rotor assembly includes rotors passing through the two pump chambers and an inlet pipe, and two impellers fitted around the rotors, each impeller positioned within one of the two pump chambers. The support mechanism includes two sets of radial support mechanisms spaced apart from the rotors and an axial support mechanism positioned between the two impellers. The radial and axial support mechanisms work together to maintain the rotor assembly in a stable suspended state. The drive mechanism drives the rotor assembly to rotate, enabling the two impellers to drive the blood circulation within the two pump chambers respectively. The pump employs sliding bearings to protect the rotor assembly, preventing impact during pump startup, abnormal conditions, or emergency situations, thus improving the stability and safety of the pump operation. The two pump chambers flow in series through the intermediate shaft hole of the bearing bore. However, this dual-heart-assisted centrifugal blood pump lacks a perfusion anticoagulation system to provide anticoagulant, which can prevent thrombosis and even embolism. However, the existing bearing structure is unsuitable for the design of a perfusion anticoagulation system. Utility Model Content

[0005] To address the problem that existing bearings are inconvenient for designing anti-coagulation systems when preventing rotor assembly collisions, this invention proposes an axially limiting sliding bearing.

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

[0007] This utility model discloses an axially limiting sliding bearing, including an upper limit ring and a lower limit ring both fixed on the connecting hole of the pump body, and an inner sliding head for fixing on the connecting rod and placed between the upper limit ring and the lower limit ring.

[0008] The beneficial effects of this utility model are:

[0009] This utility model uses an upper limit ring and a lower limit ring to limit the upper and lower movement of the rotor assembly. There is a certain distance between the upper limit ring and the lower limit ring, which facilitates the design of the injection port of the injection anticoagulant system. Attached Figure Description

[0010] 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.

[0011] Figure 1 is a schematic diagram of the structure of the magnetic levitation dual-center auxiliary device of this utility model;

[0012] Figure 2 is a schematic diagram of the pump body;

[0013] Figure 3 is a schematic diagram of the rotor assembly;

[0014] Figure 4 is a schematic diagram of the axial limiting sliding bearing;

[0015] Figure 5 is a schematic diagram of an internal sliding head;

[0016] Figure 6 is a schematic diagram of the axially limited sliding bearing achieving the upper movement limit;

[0017] Figure 7 is a schematic diagram of a radial support structure;

[0018] Figure 8 is a structural schematic diagram of the main pump chamber;

[0019] Figure 9 is a schematic diagram of the axial support structure;

[0020] Figure 10 shows the force analysis diagram of the rotor assembly;

[0021] Figure 11 is a schematic diagram of the dual-center auxiliary device of the present invention using the dual-center auxiliary function;

[0022] Figure 12 is a schematic diagram of the single-heart auxiliary function of the magnetic levitation dual-heart auxiliary device of this utility model.

[0023] The attached figures are labeled as follows:

[0024] 1-Pump body; 111-Inner pipe; 112-Outer pipe; 12-Main pump chamber; 121-Main pump outlet pipe; 13-Connecting hole;

[0025] 131-Fixed groove; 14-Secondary pump chamber; 141-External inlet pipe; 142-Secondary pump outlet pipe; 15-Bridging chamber; 16-Injection hole; 17-Lead hole; 18-Annular plate;

[0026] 2-Rotor assembly; 21-Shaft; 22-Connecting rod; 231-Main upper cover; 232-Main blade; 241-Secondary upper cover; 242-Secondary blade;

[0027] 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;

[0028] 4-Axial support structure; 41-Sensor; 42-Iron core; 43-First winding; 44-Second winding;

[0029] 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;

[0030] 61-Regulating valve; 62-First connecting pipe; 63-Second connecting pipe; 64-Third connecting pipe; 65-Second regulating valve;

[0031] 7-Electrical control system;

[0032] 8-Infusion system. Detailed Implementation

[0033] 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 generally be arranged and designed in various different configurations.

[0034] 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.

[0035] 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.

[0036] It should be noted that similar reference numerals 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. 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 figures shown.

[0037] The orientation or positional relationship of the device or component, whether it is the orientation or positional relationship commonly used when the product is in use, or the orientation or positional relationship commonly understood by those skilled in the art, is used only for the convenience of describing the present invention and simplifying the description, and is not intended to indicate or imply that the device or component referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention. Furthermore, the terms "first," "second," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0038] 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.

[0039] 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.

[0040] Referring to Figures 1 and 2, 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.

[0041] Referring to Figures 1 and 3, 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.

[0042] Referring to FIG1, 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.

[0043] Referring to FIG1, the drive assembly is used to drive the rotor assembly 2 to rotate and is disposed within the cavity 15.

[0044] 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.

[0045] 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.

[0046] 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.

[0047] 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.

[0048] 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.

[0049] 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 in the axial direction. As shown in Figure 1, the direction is downward. This is used to counteract the large attraction of the stator core to the rotor magnet. Furthermore, the electromagnet can also determine the axial position of the impeller and the direction and magnitude of the axial force at any time through sensor detection. 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.

[0050] The main cover 231 and the secondary cover 241 are coaxial and parallel to each other.

[0051] Further, as shown in Figure 8, an annular plate 18 is provided inside 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, with the distance between the annular plate 18 and the bottom of the main pump chamber 12 gradually increasing from its outer diameter to its inner diameter. That is, the annular plate 18 has a concave structure, forming a backflow channel with the bottom of the main pump chamber 12. The backflow channel inlet is the gap between the annular plate 18 and the side wall of the main pump chamber 12, and the backflow channel outlet is the gap between the annular plate 18 and the rotor assembly 2. The pressure ratio at the backflow channel inlet is...

[0052] The high pressure at the outlet of the reflux channel, driven by the pressure difference, can effectively flush the sliding bearing port and prevent thrombosis.

[0053] Furthermore, in 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.

[0054] 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.

[0055] 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.

[0056] The axial support structure 4 achieves axial suspension balance of the rotor assembly 2, as shown in Figure 9. It includes a sensor 41 for detecting the axial movement of the rotor assembly 2, multiple iron cores 42 evenly distributed around the connecting rod 22, and a first winding 43 wound on the iron cores 42.

[0057] The sensor can be implemented as a position sensor, distance sensor, etc.

[0058] The iron core 42 has 6 cores, and one end is plate-shaped.

[0059] 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.

[0060] 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.

[0061] Using the aforementioned axial support structure 4 and drive structure, during operation, the main upper cover 231 and the upper cavity surface of the main pump chamber 12 form the main return flow channel, and the auxiliary upper cover 241 and the upper cavity 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. The 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.

[0062] Weak influencing factors can be disregarded in the analysis. As shown in Figure 10, 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. Among them, F1 is the attraction force generated by the rotor magnet of the motor on the stator core 42, and the direction of the force is axially upward. The magnitude of the force is positively correlated with the mass and distance between the two. 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 F1 value is large, while the downward hydraulic pressures F1 and F2 vary greatly due to the uncertain rotational speed, the resultant force of F2 and F3 is insufficient to offset F1 when the rotor assembly is running at low speed. When the rotor assembly experiences a slight axial displacement, including upward displacement of the impeller at low speeds or 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 resultant 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.

[0063] 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.

[0064] 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. Figure 4 As shown in Figure 6, 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.

[0065] There are many ways to implement the inner sliding head 51 and its upper limit ring 52 and lower limit ring 53, for example,

[0066] The upper limit ring 52 and lower limit ring 53 are plate-shaped, and the inner sliding head 51 is cylindrical. The outer diameter of the inner sliding head 51 is larger than the inner diameter of the upper limit ring 52 and the inner diameter of the lower limit ring 53. In order to improve the smoothness of the flow of anticoagulant to the main pump chamber 12 and the auxiliary pump chamber 14, preferably, as shown in Figures 4 and 5, both ends of the inner sliding head 51 are provided with a first sectional structure 511. The upper limit ring 52 and the lower limit ring 53 are respectively provided with a second sectional structure 521 and a third sectional structure 531 parallel to the first sectional structure 511 at the corresponding positions. The injection hole 16 is disposed between the second sectional structure 521 and the third sectional 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, and 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] Preferably, in order to improve the smoothness of the flow of the anticoagulant, a gap is provided between the inner sliding head 51 and the inner wall of the connecting hole 13, that is, the outer diameter of the inner sliding head 51 is smaller than the diameter of the connecting hole 13.

[0070] The injection hole 16 is located between the upper limit ring 52 and the lower limit ring 53. Furthermore, in order to facilitate the setting of the injection hole, the distance between the upper limit ring 52 and the lower limit ring 53 is greater than the diameter of the injection hole 16.

[0071] Axial limiting sliding bearings with any of the above structures can limit the vertical movement of the rotor assembly, preventing it from impacting or scraping the pump chamber and causing safety accidents, thus avoiding complications such as thrombosis and hemolysis. They also facilitate the installation of the infusion port and the infusion anticoagulant system. In addition to vertical limiting, radial limiting can also be achieved to prevent mechanical wear and damage caused by malfunctions or accidents.

[0072] 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.

[0073] There are many ways to implement the radial support structure 3. For example, the structure disclosed in patent application number 202311849700.3 is used in 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;

[0074] 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.

[0075] 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.

[0076] 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.

[0077] 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 are radially magnetized, with one polarity in the radial direction and one in the inner direction. The second permanent magnet segment 32 is axially magnetized, meaning that the two ends have different polarities. The upper, middle, and lower magnet segments are stacked together in the inner ring.

[0078] From the outside, the two permanent magnet rings appear to be attached together on the same magnetic poles. 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 and one in the inner direction. The fifth permanent magnet segment 35 is axially magnetized. The upper, middle, and lower magnetic rings are stacked together and appear to be attached together on the same magnetic poles from the outside. 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. When the axial alignment is maintained, the inner and outer magnetic groups can achieve radial magnetic levitation.

[0079] 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.

[0080] 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. Setting the two sets of radial support structures 3 coaxially and axially aligned 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 10mm and less than 15mm.

[0081] For example, if the axial direction of the shaft is defined as the up-down direction, as shown in Figure 4, 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; the polarity of the outer diameter surface of the third permanent magnet segment 33 is N pole, and the polarity of the inner diameter surface is S pole. The outer diameter surface of the fourth permanent magnet segment 34 has the N pole polarity, and the inner diameter surface has the S pole polarity. The upper and lower ends of the fifth permanent magnet segment 35 have the N pole and the S pole polarity, respectively. The outer diameter surface of the sixth permanent magnet segment 36 has the S pole polarity, and the inner diameter surface has the 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 the magnetic short circuit 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.

[0082] 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.

[0083] Radial support structure 3 uses strong permanent magnet material of type 52-58 neodymium iron boron.

[0084] An external infusion system delivers heparin-based anticoagulant into the cavity of pump body 1 through infusion port 16. A lead hole can be provided on pump body 1 for the delivery pipe of the infusion system and the axial support structure 4 and drive assembly.

[0085] The control line is externally connected. The heparin-based anticoagulant delivered by the perfusion system can flush the bearing port of the axial limiting sliding bearing through the perfusion hole 16, thus acting as a dynamic seal for the bearing. The anticoagulant can prevent blood clotting and thrombus formation; the perfusion fluid can also lubricate the bearing.

[0086] 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.

[0087] 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.

[0088] For patients with dual heart failure, referring to Figure 11, a magnetically levitated dual-heart assist device is installed in the patient's chest cavity via open-chest surgery. 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 orifice. A first regulating valve 61 is installed on the first connecting tube to regulate flow. The external inlet tube 141 is connected to a second connecting tube 63 and 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 orifice. A second regulating valve 65 is installed on the third connecting tube 64 to regulate flow. The signal wire of the winding coil is led out of the patient's body through the 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.

[0089] 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 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 reduces the diameter of the main pump outlet pipe, decreasing the flow rate; closing it completely shuts off the flow. If the right ventricle recovers, adjusting the second regulating valve 65 reduces the diameter of the auxiliary pump outlet pipe, decreasing the flow rate; closing it 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 to a very low level is sufficient. The motor continues to rotate, maintaining the necessary flow assistance to the other failing ventricle. Because of the infusion of anticoagulant, the blood inside the shut-off auxiliary pump and at the connected ventricular inlet will not be pumped.

[0090] Internal coagulation and thrombosis; when the patient experiences heart failure again and needs to restart the auxiliary function of the shut-off pump, simply increase the outlet regulating valve, which is very convenient to operate; because of the regulating valve, the left and right ventricular assist functions work well together, and the flow matching is adjustable.

[0091] When only the main pump is installed, as shown in Figure 12, 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, so there is no need to worry about complications such as thrombosis.

[0092] With the above structure, the main upper cover 231, i.e. the magnet, is located in 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.

[0093] 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.

[0094] 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. An axially limiting sliding bearing, characterized in that, It includes an upper limit ring (52) and a lower limit ring (53) fixed on the connecting hole (13) of the pump body (1), an inner sliding head (51) for fixing on the connecting rod (22) and placed between the upper limit ring (52) and the lower limit ring (53), and a filling hole (16).

2. The axially limiting sliding bearing according to claim 1, characterized in that, Both ends of the inner sliding head (51) are provided with a first slit structure (511). The upper limit ring (52) and the lower limit ring (53) are respectively provided with a second slit structure (521) and a third slit structure (531) parallel to the first slit structure (511) at the corresponding positions of the upper limit ring (521) and the lower limit ring (531). The injection hole (16) is located between the second slit structure (521) and the third slit structure (531).

3. The axially limiting sliding bearing according to claim 1, characterized in that, The inner sliding head (51) is cylindrical, and the upper limit ring (52) and lower limit ring (53) are sheet-like. The outer diameter of the inner sliding head (51) is greater than the inner diameter of the upper limit ring (52) and the inner diameter of the lower limit ring (53).

4. The axially limiting sliding bearing according to claim 1, characterized in that, A gap is provided between the inner sliding head (51) and the inner wall of the connecting hole (13).

5. An axially limiting sliding bearing according to claim 1, characterized in that, The connecting hole (13) is located between the upper limit ring (52) and the lower limit ring (53) and is provided with an injection hole (16).

6. An axially limiting sliding bearing according to claim 5, characterized in that, The distance between the upper limit ring (52) and the lower limit ring (53) is greater than the diameter of the injection hole (16).

7. An axially limiting sliding bearing according to claim 1, characterized in that, The sidewall of the connecting hole (13) is provided with a fixing groove for fixing the upper limit ring (52) and the lower limit ring (53).

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