An impeller assembly, a mold, and a fluid pumping system

Abstract

The present disclosure provides a kind of impeller assembly, mould and a kind of fluid pumping system, wherein the impeller assembly includes rotating shaft, which is axially provided with hollow structure;Hub, at least part of which is embedded in the hollow structure of the rotating shaft;Blade, the root of the blade is connected with the hub, and the blade extends radially outward along the rotating shaft;At least one of the axial ends of the blade includes a reinforcing portion, which is arranged on the hub.The scheme of the present disclosure changes the flow field distribution around the impeller, and improves the stability of the rotation of the impeller.

Description

Technical Field

[0001] This disclosure relates to the field of fluid machinery technology, specifically to an impeller assembly, a mold, and a fluid pumping system. Background Technology

[0002] Interventional ventricular assist devices (VADs) are commonly used fluid pumping devices to assist cardiac blood circulation in patients with heart failure. Among related technologies, foldable impeller designs exist. However, these designs suffer from drawbacks including high manufacturing complexity, large radial dimensions after folding, and poor blade motion stability. While increasing blade thickness can improve operational stability, it leads to an increase in impeller size. Therefore, reducing impeller size, especially after folding, while ensuring stable impeller operation, and mitigating manufacturing difficulty and costs are pressing issues that need to be addressed. Utility Model Content

[0003] In order to overcome at least one of the many problems in the related art, this disclosure provides an impeller assembly, a mold, and a fluid pumping system.

[0004] The first aspect of this disclosure provides an impeller assembly, comprising:

[0005] A rotating shaft with a hollowed-out structure along its axial direction;

[0006] The hub is at least partially embedded in the hollow structure of the rotating shaft;

[0007] The blade has its root connected to the hub and extends radially outward along the axis of rotation;

[0008] At least one of the axial ends of the blade includes a reinforcing portion, which is disposed on the hub.

[0009] In some alternative embodiments, the radial dimension of the portion of the reinforcement closer to the end of its adjacent rotating shaft is smaller.

[0010] In some optional embodiments, the blade further includes a main body and a transition portion, wherein the axial sides of the transition portion are respectively connected to the main body and the reinforcing portion;

[0011] The radial dimension of the main body is greater than the radial dimension of the reinforcing part, and the radial dimension of the transition part is between the radial dimension of the main body and the radial dimension of the reinforcing part.

[0012] In some optional embodiments, the outer contour curve of the transition portion is a convex shape away from the rotation axis; and / or, the outer contour curve of the reinforcing portion is a concave shape close to the rotation axis.

[0013] In some alternative embodiments, the blades may retract or expand relative to the axis of rotation.

[0014] In some optional embodiments, the side wall of the rotating shaft is provided with an injection molding opening that communicates with the hollow structure;

[0015] The hub includes an inner hub and an outer hub. The inner hub is embedded in the hollow structure, and the outer hub at least partially covers the outer wall surface of the side wall of the rotating shaft. The inner hub and the outer hub are correspondingly connected to the injection opening.

[0016] The root of the blade is connected to the outer hub.

[0017] In some optional embodiments, the inner hub and the outer hub are integrally formed.

[0018] In some optional embodiments, the inner hub, the outer hub, and the blade are integrally formed.

[0019] In some optional embodiments, the hollow structure extends through the distal end of the rotating shaft along the axial direction, and the distal and proximal ends of the rotating shaft are at least partially not covered by the outer hub.

[0020] The portion of the rotating shaft not covered by the outer hub at its distal end includes a first positioning part, and the portion of the rotating shaft not covered by the outer hub at its proximal end includes a second positioning part.

[0021] In some optional embodiments, the first positioning part and the second positioning part are respectively configured to be adapted to the processing mold.

[0022] In some alternative embodiments, the distal end of the inner hub extends beyond the distal end of the hollow structure to form the hub end.

[0023] In some alternative embodiments, the radial dimension of the hub end is tapered along the direction from the proximal end to the distal end to form a guide surface.

[0024] In some optional embodiments, the side wall of the rotating shaft is provided with an injection molding opening that communicates with the hollow structure;

[0025] The blade and the outer hub have a mating position; the extended shape of the injection opening matches the shape of the mating position.

[0026] A second aspect of the present invention provides a machining mold for an impeller assembly, the machining mold being used to machine any of the impeller assemblies described in the first aspect.

[0027] The processing mold has a forming cavity, which includes:

[0028] A first cavity extends axially and is used to accommodate a rotating shaft, the first cavity being radially clearance-fitted with the rotating shaft;

[0029] The second cavity is connected to the first cavity and extends radially by a predetermined distance from the sidewall of the first cavity. The cavity shape of the second cavity matches the blade, and the second cavity is used to form the blade.

[0030] In some optional embodiments, the distal and proximal ends of the first cavity are respectively provided with clamping portions;

[0031] The distal clamping portion mates with the corresponding portion at the distal end of the rotating shaft, and the proximal clamping portion mates with the corresponding portion at the proximal end of the rotating shaft.

[0032] A third aspect of the present invention provides a fluid pumping system, including a drive assembly and an impeller assembly as described in any of the first aspects, wherein the drive assembly drives the impeller assembly to operate in order to pump fluid.

[0033] The technical solution disclosed herein has the following advantages or beneficial effects:

[0034] (1) In some embodiments of this disclosure, the hub includes an inner hub and an outer hub. The inner hub is embedded in the hollow structure, and the outer hub at least partially covers the outer wall surface of the sidewall of the rotating shaft. At least one of the axial ends of the blade includes a reinforcing portion, which is connected to the outer hub. The radial dimension of the portion of the reinforcing portion closer to the adjacent end of the rotating shaft is shorter. This structure allows blood to first contact the reinforcing portion and enter the impeller during impeller operation. The gradually changing radial dimension of the reinforcing portion guides the blood movement, reducing the impact of blood on the blade and ensuring the stability of the blade movement. During the process of blood leaving the blade, the downstream reinforcing portion further guides the fluid to flow along the radially narrowing structure, avoiding fluid separation caused by abrupt changes in the blade structure and further reducing the impact force of eddies on the blade. In addition, the reinforcing portion connects the blade body and the outer hub, increasing the contact area between the blade and the outer hub, so that the outer hub can provide sufficient support for the blade.

[0035] (2) In some embodiments of this disclosure, the radial dimension of the transition portion is between the radial dimension of the main body and the radial dimension of the reinforcing portion, so as to gradually transition the outer contour of the blade to the reinforcing portion and ensure the smoothness of the blade profile. The outer contour curve of the transition portion presents a convex shape away from the rotation axis; and / or, the outer contour curve of the reinforcing portion presents an inward shape close to the rotation axis; so that the large diameter of the main body smoothly transitions to the small diameter at the reinforcing portion, so that the fluid can smoothly achieve body-fitting motion, and avoid the fluid entering the impeller and generating eddies due to separation, which would reduce the efficiency of transporting fluid when the blade rotates at high speed, and aggravate the instability of motion due to the violent reaction force generated by the eddies.

[0036] (3) In some embodiments of this disclosure, the first positioning part at the distal end of the rotating shaft and the second positioning part at the proximal end of the rotating shaft are used to position the rotating shaft. That is, by fixing both ends of the rotating shaft to position it, its axis is ensured to be in a set position so that the rotating shaft is coaxial with the impeller composed of blades and hub, thereby improving the motion stability of the impeller assembly. Attached Figure Description

[0037] The accompanying drawings are provided to better understand this disclosure and do not constitute an undue limitation thereof. Wherein:

[0038] Figure 1 This is a front view schematic diagram of an impeller assembly according to some embodiments of the present disclosure;

[0039] Figure 2 This is a schematic diagram of the outline of the blades in an impeller assembly according to some embodiments of the present disclosure;

[0040] Figure 3 This is a perspective view of a rotation axis according to some embodiments of the present disclosure;

[0041] Figure 4 This is a cross-sectional schematic diagram of a rotating shaft according to some embodiments of the present disclosure;

[0042] Figure 5 This is a front view schematic diagram of an impeller assembly according to some embodiments of the present disclosure;

[0043] Figure 6 This is a cross-sectional schematic diagram of an impeller assembly according to some embodiments of the present disclosure. Detailed Implementation

[0044] The exemplary embodiments of this disclosure are described below with reference to the accompanying drawings, including various details of the embodiments to aid understanding, and should be considered merely exemplary. Therefore, those skilled in the art will recognize that various changes and modifications can be made to the embodiments described herein without departing from the scope and spirit of this disclosure. Similarly, for clarity and brevity, descriptions of well-known functions and structures are omitted in the following description.

[0045] The terminology used in this application is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. The singular forms “a,” “the,” and “the” used in this application and the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise. It should also be understood that the term “and / or” as used herein refers to and includes any or all possible combinations of one or more of the associated listed items.

[0046] It should be understood that although the terms first, second, third, etc., may be used in this application to describe various information, such information should not be limited to these terms. These terms are only used to distinguish information of the same type from one another. For example, without departing from the scope of this application, first information may also be referred to as second information, and similarly, second information may also be referred to as first information. Depending on the context, the word "if" as used herein may be interpreted as "when," "when," or "in response to determination."

[0047] Furthermore, it should be noted that in the description of the embodiments of this application, unless otherwise explicitly defined, "in vivo" means inside the patient's tissues and organs, and "outside the body" means outside the patient's tissues and organs. Also, in the embodiments of this application, "distal" refers to the direction away from the physician, and "proximal" refers to the direction closer to the physician.

[0048] This application provides an interventional ventricular assist device (or interventional catheter device), which is commonly used to assist patients with heart failure in maintaining cardiac blood circulation. The device includes a pump head and a drive assembly connected to the pump head. The pump head includes a pump housing and an impeller assembly, the impeller assembly being disposed within the pump housing. The drive assembly is connected to the rotating shaft of the impeller assembly and is used to drive the rotating shaft to rotate, providing flow power to the blood, thereby providing stable blood delivery support to the patient and reducing the burden on the heart.

[0049] The impeller assembly is an important component of the pump head. In order to reduce the interventional size of interventional ventricular assist devices, most interventional ventricular assist devices currently use foldable impeller assemblies. These assemblies can be folded during the intervention and unfolded after the intervention is in place, thereby reducing the interventional size and preventing damage to blood vessels or corresponding organs.

[0050] While existing impeller assemblies employ a folded design to reduce the interventional size of ventricular assist devices, the stability of their rotational motion after the blades are unfolded is poor. This is because the blades, operating at high speed, are affected by blood flow forces. The pressure difference between the upstream and downstream surfaces of the blades causes deformation under blood pressure / impact. Excessive deformation can affect the pumping and hemolytic performance of the impeller assembly. Increasing blade thickness can improve the blades' resistance to deformation, thereby reducing instability. However, this solution would increase the radial dimension of the impeller assembly, affecting the interventional size of the ventricular assist device.

[0051] Therefore, in order to overcome at least one of the many problems in the related art, the first aspect of this disclosure provides an impeller assembly.

[0052] like Figure 1 As shown, the impeller assembly includes a rotating shaft 1. In some embodiments, the rotating shaft may be a single-diameter structure, i.e., the rotating shaft is a rod-shaped structure of uniform thickness, for example, the outer diameter of the rotating shaft is 0.6-2 mm, preferably 0.8-1.2 mm. See also Figure 3 and 4 The rotating shaft has a hollow structure 11 along the axial direction X inside. To reduce manufacturing costs, the internal contour shape and size of the hollow structure are also the same. In practice, a material with a certain rigidity, such as metal, can be selected, and the hollow structure can be machined inside to form the rotating shaft. The cross-sectional shape of the hollow structure 11 can be circular, square, or other shapes, preferably circular, as it is easier to process and manufacture.

[0053] See Figure 6 The diagram shows a schematic longitudinal section of the impeller assembly. The hub 22 includes an inner hub 211 and an outer hub 212. A small portion of the inner hub is embedded in the hollow structure of the rotating shaft, while the outer hub at least partially covers the outer wall of the rotating shaft. In some embodiments, the inner hub may be entirely embedded in the hollow structure. Preferably, filling the hollow structure with the inner hub prevents gaps from forming between the inner hub and the outer wall of the hollow structure, thereby preventing fluid from being stored in these gaps and addressing the problem of blood disruption during the fluid pumping process of the ventricular assist device.

[0054] Blade 22, the root of which connects to the hub to form impeller 2. The outer edge of the blade passes through the hollow structure of the rotating shaft and extends outward along the radial direction of the rotating shaft. The blade is elastic and can contract or expand relative to the rotating shaft. For example, the blade 22 can wrap around the rotating shaft to be in a contracted state and naturally expand after the constraint is released. During intervention, the blade moves towards the axis of the rotating shaft to reduce the overall outer diameter of the impeller assembly and maintains a compressed state during intervention; when the target point is reached, the radial constraint force on the blade is released, and it fully expands by relying on its own elastic recovery deformation. Figure 6 As shown, the hub in this disclosure is at least partially disposed within a hollow structure inside the rotating shaft, and partially covers the rotating shaft. The connection between the blades and the hub is also located inside and outside the rotating shaft. This connection method not only improves the connection strength at the blade root, reduces deformation during high-speed rotation, and improves motion stability, but also significantly reduces the overall outer diameter of the impeller with blades of a certain height. This reduces the radial dimension from the rotating shaft to the outer edge of the blade, thus allowing for a smaller overall radial dimension of the impeller in this application. The rotating shaft provides the hub with an internal mounting cavity and an outer support wall, thereby stably supporting and protecting the hub. This allows the hub to provide stable rotational support force to the blades without requiring a large radial dimension, while also preventing damage to the hub under the reaction force of the impeller. It is understood that when a material with suitable stiffness and strength is selected to manufacture the rotating shaft, the outer diameter of the rotating shaft can be further reduced, thereby further compressing the radial dimension of the impeller assembly in this disclosure.

[0055] refer to Figures 3 to 4The side wall of the rotating shaft 1 has injection openings 12 that communicate with the hollow structure 11. The number of injection openings can be equal to or greater than the number of blades. These injection openings allow the hub 21 and blades 22 to be integrally injection molded during the injection molding process; and the inner hub 211 and outer hub 212 are correspondingly connected to the injection openings 12. In this embodiment, the impeller assembly, by dividing the hub 21 into an inner hub 211 and an outer hub 212, and placing the inner hub 211 within the hollow structure 11 of the rotating shaft 1, and connecting the inner hub 211 and outer hub 212 to the injection openings 12 on the rotating shaft 1, ensures the supporting strength of the impeller assembly by having both the inner and outer hubs 211 and 212 bear the load simultaneously. This reduces the deformation of the blades 22 under the reaction force of the fluid during high-speed operation, while also improving the stability of the impeller 2 during winding and unwinding, and enhancing the reliability of the impeller assembly. Furthermore, under the same support strength, the thickness of the outer hub 212 can be reduced, and the radial dimension of the impeller assembly after winding can be reduced, thereby reducing the intervention size during the intervention of the ventricular assist device, reducing damage to blood vessels or corresponding organs, and reducing patient suffering.

[0056] Understandably, compared to methods that rely solely on the outer hub to bear the axial or radial forces of the blades, the impeller assembly in this embodiment can bear forces simultaneously through both the inner and outer hubs. This minimizes the size of the outer hub, thereby reducing the overall diameter of the hub and the pressure dimension during impeller radial clamping. Furthermore, by retaining a certain thickness of the outer hub in the impeller assembly of this embodiment, compared to methods that only use the inner hub, it is easier to mate the rotating shaft with the injection mold, reducing injection molding difficulty. Simultaneously, the formed inner and outer hubs are tightly fitted to the rotating shaft, reducing the risk of blood entering the gap between the hub and the rotating shaft during blood pumping by the interventional catheter device. Additionally, by using both the inner and outer hubs, the connection strength between the impeller and the rotating shaft in the axial and radial directions is increased, enhancing the support strength for the blades, reducing the deformation of the blades under fluid reaction forces during high-speed operation, and improving pumping performance.

[0057] Understandably, when a material with suitable stiffness and strength is selected to manufacture the rotating shaft 1, the outer diameter of the rotating shaft 1 can be further reduced, thereby further compressing the radial dimension of the impeller assembly of this application. At the same time, the rotating shaft 1 provides a mounting cavity for the inner hub 211, and the hollow structure 11 can stably support and protect the inner hub 211, so that the outer hub 212 does not need to have a large radial dimension to provide stable rotational support force for the blade 22, while also preventing the hub 21 from being damaged under the reaction force of the impeller 2.

[0058] Optionally, the radial dimension of the outer hub 212 is 0.05mm-0.1mm. By setting the radial dimension of the outer hub 212 to be greater than or equal to 0.05mm, it is easier to match the rotating shaft 1 with the injection mold and reduce the injection molding difficulty. By setting the radial dimension of the outer hub 212 to be less than or equal to 0.1mm, it is possible to provide stable rotational support force for the blade 22 while reducing the size of the outer hub 212, thereby reducing the overall diameter of the hub 21 and reducing the intervention size of the impeller assembly.

[0059] Further, see Figure 1 3 and 5, at least one of the axial ends of the blade includes a reinforcing portion. For example Figure 2 In the process, a reinforcing portion can be provided at each of the axial ends of the blade 22, namely the far-end reinforcing portion 1003 and the near-end reinforcing portion 1005 in the figure. The reinforcing portions are connected to the outer hub. During injection molding, at least the reinforcing portions, the blade body, and the outer hub are integrally injection molded. The radial dimension of the portion of the reinforcing portion closer to its adjacent rotating shaft end is shorter. For example... Figure 2 As shown, the radial dimension of the distal reinforcing portion 1003 gradually decreases as it extends towards the distal end of the rotating shaft along the axis of rotation; the radial dimension of the proximal reinforcing portion 1005 gradually decreases as it extends towards the proximal end of the rotating shaft along the axis of rotation. In some embodiments, the outer edge contour of the distal end of the reinforcing portion and / or the outer edge contour of the proximal end of the reinforcing portion merges with the outer hub. As described above, during pumping, blood first contacts the reinforcing portion and enters the impeller. Due to the gradually decreasing radial dimension of the reinforcing portion guiding the blood movement, the impact of blood on the blade is reduced, ensuring the stability of the blade movement. As the blood leaves the blade, the downstream reinforcing portion further guides the fluid to flow along the radially decreasing structure, avoiding fluid separation caused by abrupt changes in the blade structure, further reducing the impact force of eddies on the blade. More advantageously, since the reinforcing portion connects the blade body and the outer hub, it increases the contact area between the blade and the outer hub, allowing the outer hub to provide sufficient support for the blade. It is evident that the coordinated effect of the reinforced structure's placement, geometry, and connection points enhances the blade's motion stability during high-speed rotation.

[0060] See Figure 2As shown, in some optional embodiments, the blade further includes a main body 1001 and transition portions 1002 and 1004, with the main body and the reinforcing portion respectively connected to its axial sides. The radial dimension of the main body is larger than that of the reinforcing portion, and the radial dimension of the transition portion is between that of the main body and the reinforcing portion. By providing a transition portion on the side of the main body 1001 near the end of the rotation axis, the outer contour of the blade gradually transitions to the reinforcing portion, ensuring a smooth blade profile. Figure 2 In this design, the blade's main body 1001 has a transition portion 1002 at its distal end and a transition portion 1004 at its proximal end. The radial dimension of the transition portion is between the radial dimensions of the main body and the reinforcing portion, and it tapers from the blade's main body to the reinforcing portion. The spatial shape of the transition portion and the reinforcing portion continuously twists with the blade, resulting in a smooth blade surface and ensuring efficient blood delivery during pumping. In some embodiments, the radial dimension of the main body remains constant, meaning the main body extends along the axis of rotation with the same diameter. Figure 2 In this embodiment, to clearly illustrate the connection between the blade body, transition section, and reinforcing section at the outer edge of the blade, their outer contours are marked with thick black lines. The outer contour curve of the transition section presents a convex shape away from the rotation axis; and / or, the outer contour curve of the reinforcing section presents an inward concave shape close to the rotation axis. In other words, the curvature directions of the outer contour curves of the transition section and the reinforcing section are opposite. To clearly illustrate the curvature of the outer contour, in this embodiment, the rotation axis is used as a reference point, and the overall curve of the reinforcing section presents an inward concave shape close to the rotation axis; if the outer contour curve of the reinforcing section is approximated as an arc, its center is located on the side of the outer contour away from the rotation axis. The overall curve of the transition section presents a convex shape away from the rotation axis; if the outer contour curve of the transition section is approximated as an arc, its center is located on the side of the outer contour close to the rotation axis. Figure 2 As shown, the large diameter of the blade body is smoothly transitioned to the small diameter at the reinforcing part by two outer contours with opposite curved shapes, which allows the fluid to smoothly achieve body-fitting motion. This avoids the fluid from generating eddies after entering the impeller, which would reduce the efficiency of fluid transport when the blade rotates at high speed and exacerbate the instability of motion due to the violent reaction force generated by the eddies.

[0061] In some optional embodiments, the impeller 2 may be made of an elastic material, and the blades 22 may be wound (or compressed, folded, etc.) or unfolded about the rotation axis 1. The impeller 2 may be driven to rotate about the rotation axis to transport fluid in the axial direction X, and by making the impeller 2 of an elastic material, the impeller 2 can switch between a compressed state and an expanded state. The compressed state refers to the radially contracted state of the blades 22 under radial external force during storage, transportation, assembly, etc., while the expanded state refers to the natural expanded state of the blades 22 when no external force is applied. The blades 22 contain a strength-reinforcing material. It is understood that since the blades 22 need to switch between folded and unfolded states and effectively promote blood flow, they need to have both sufficient elasticity and sufficient strength. Therefore, in a preferred embodiment, the blades 22 are injection molded from a sufficiently elastic injection molding material, and reinforcing materials are added to the blades 22 to ensure sufficient strength. For example, fibers are added. Preferably, the Shore hardness of the injection molding material is >90A, and the injection molding material contains fibers, thereby improving injection molding efficiency and ensuring the strength of the blades 22.

[0062] See Figures 3 to 4 In some optional embodiments, the hollow structure 11 extends along the axial direction of the rotation shaft; the outer edge of the blade passes through the injection molding opening and through the rotation shaft. The hollow structure is formed inside the rotation shaft by drilling. The hollow structure can be a blind hole structure or a... Figure 4 The through-hole structure is shown. Furthermore, to facilitate the manufacturing of the hub and blades and to connect them with high strength, some embodiments of this disclosure employ a one-piece injection molding process to process the hub and blades. For this purpose, it is necessary to further provide injection openings on the rotating shaft corresponding to the blade positions. For example... Figure 3 and 4 The embodiments shown can be implemented through [the following methods] in actual processing: Figure 3The proximal end (or injection port) shown is filled with injection molding material. After flowing through the hollow structure, the injection molding material enters the radially extending injection opening and flows radially outward, leaving the rotating shaft and finally entering the mold forming the blade. Thus, in this embodiment, the hollow structure is connected to the injection opening; the hub and blade are integrally formed by sequentially injecting the injection molding material through the hollow structure and injection opening. This manufacturing process not only facilitates the processing of the hub and blade, effectively solving the connection problem between the blade and the hub, but also, more importantly, allows the hub to be embedded inside the rotating shaft, and the blade root to be embedded inside the rotating shaft through the injection opening. This ensures that both the hub and blade are tightly fitted to the rotating shaft, increasing the connection strength between the hub / blade and the rotating shaft in both axial and radial directions. This effectively limits the relative displacement between the blade and the rotating shaft during high-speed rotation, increases the support effect at the blade root, reduces the deformation of the blade under fluid reaction force during high-speed operation, and improves fluid pumping performance. Optionally, the injection port can also be located at the distal end of the rotating shaft. Furthermore, the distal and proximal ends of the rotating shaft are at least partially not covered by the outer hub. For example... Figure 5 As shown, the distal end 1101 of the rotating shaft is at least partially not covered by the outer hub, and correspondingly, the proximal end 1102 is also at least partially not covered by the outer hub. The portion of the rotating shaft not covered by the outer hub at the distal end includes a first positioning portion, and the portion of the rotating shaft not covered by the outer hub at the proximal end includes a second positioning portion. The first positioning portion may be at least some areas of the portion of the distal end not covered by the outer hub, or an additional positioning portion; the second positioning portion may be at least some areas of the portion of the proximal end not covered by the outer hub, or an additional positioning portion. The first and second positioning portions are used to position the rotating shaft. In some embodiments, the first and second positioning portions are respectively configured to be adapted to the processing mold. During actual injection molding, the first and second positioning portions at the distal and proximal ends of the rotating shaft can be clamped by the mold to achieve positioning of the rotating shaft. It is understandable that the blades, outer hub, and inner hub all rotate with the rotation of the rotating shaft. During the injection molding process, if the axis of the rotating shaft is not aligned with the axis of the blade during its working state, it will cause uneven rotation of the blade, affecting its motion stability. Therefore, in this embodiment, the two ends of the rotating shaft are clamped to position it, ensuring that its axis is in a set position so that the rotating shaft is coaxial with the impeller formed by the blades and hub.

[0063] See Figure 6In some optional embodiments, the hollow structure 11 extends through the distal end of the rotating shaft 1 along the axial direction X. The inner hub 211 and the outer hub 212 are not connected at the distal end of the rotating shaft 1. The portion of the inner hub extending beyond the distal end of the hollow structure forms a hub end 213. Along the axial direction X, from the proximal end to the distal end, the radial dimension of the hub end 213 gradually decreases, forming a guide surface. By forming a guide surface on the outer surface of the hub end 213, the axial blood flow can be guided uniformly and stably into the impeller 2 region, reducing turbulence, improving pumping performance, and reducing the probability of red blood cell damage. Optionally, the outer surface of the hub end 213 has an arc-shaped transition, thereby forming a streamlined hub end 213 with better guiding effect. In some optional embodiments, the guide surface is a guide cone surface, and the included angle at the top of the guide cone surface is 30°-80°. It is understandable that when the outer surface of the hub end 213 is set with an arc transition, the included angle at the top of the guide cone is the included angle between the tangents of the two arc surfaces. By controlling the included angle at the top of the guide cone, the drainage angle of the axial X blood flow can be controlled to better improve the blood pumping performance.

[0064] In some alternative embodiments, the blade and the outer hub have a mating position; the extended shape of the injection opening 12 matches the shape of the mating position, thereby shortening the force transmission path when the blade 22 is under force, making it easier to apply the force to the hub, especially in embodiments with an outer hub and an inner hub, which can better provide support for the blade. However, it should be noted that the matching can mean that the lengths of the two are the same; it can also mean that the length of the injection opening is shorter than the length of the mating position between the blade 22 and the hub. Figure 2 The latter is shown. Due to the presence of the reinforcement, its engagement point with the hub does not at least partially match the extension trajectory of the injection molding opening. In other words, the engagement point of the reinforcement with the hub is at least partially located outside the injection molding opening.

[0065] The high manufacturing difficulty and performance limitations of existing blades are significant technical problems that urgently need to be addressed. Therefore, reducing the manufacturing difficulty of blades and improving their performance and yield are issues that some embodiments of this disclosure aim to solve. To this end, a second aspect of this disclosure provides a processing mold (or injection mold) for impeller assemblies, used for processing any of the aforementioned impeller assemblies.

[0066] In some optional embodiments, a forming cavity is provided in the processing mold. The forming cavity includes a first cavity and a second cavity that are connected to each other. The first cavity extends along the axial direction X and is used to accommodate the rotating shaft 1. The first cavity is in clearance fit with the rotating shaft 1 along the radial direction Y. The second cavity is connected to the first cavity and extends a predetermined distance along the radial direction Y from the side wall of the first cavity. The cavity shape of the second cavity matches the blade 22. The second cavity is used to form the blade 22.

[0067] The injection mold in this embodiment is used to cooperate with the rotating shaft 1 to manufacture the hub 21 and blade 22 through an integral injection molding process. The hub 21 includes an inner hub 211 and an outer hub 212. The inner hub 211 is formed by the hollow structure 11 inside the rotating shaft 1, and the outer hub 212 is formed through the radial gap between the inner wall of the first cavity and the rotating shaft 1. The blade 22 is formed by the second cavity.

[0068] The impeller assembly formed by the aforementioned injection mold can fix the impeller 2 and the rotating shaft 1 together through injection molding. The inner hub 211, outer hub 212, and blades 22 are all tightly fitted to the rotating shaft 1, thereby increasing the connection strength between the impeller 2 and the rotating shaft 1 in the axial (X) and radial (Y) directions. This effectively limits the relative displacement between the blades 22 and the rotating shaft 1 during high-speed rotation, increases the root support effect of the blades 22, reduces the deformation of the blades 22 under the reaction force of the fluid during high-speed operation, and improves the fluid pumping performance. Furthermore, the first cavity has a clearance fit with the rotating shaft 1 along the radial (Y) direction, which makes it easier to assemble the rotating shaft 1 into the injection mold, reduces contact wear on the rotating shaft 1 and / or the injection mold during assembly, improves the reliability of the injection molding process, and extends the mold life.

[0069] Optionally, the injection mold may include multiple injection mold units, which are assembled to form the injection mold. Specifically, the first cavity has a cylindrical structure, and the second cavity extends radially from the cylindrical wall of the first cavity. That is, the first cavity is specifically a cylindrical structure fitted onto the side wall of the rotating shaft 1, and the cylindrical wall of the first cavity is at least partially clearance-fitted with the side wall of the rotating shaft 1, thereby facilitating the insertion of the rotating shaft into the first cavity and realizing the fit between the rotating shaft 1 and the injection mold. At the same time, after injecting injection material into the hollow structure of the rotating shaft 1, an annular outer hub can be formed between the outer wall of the rotating shaft 1 and the cylindrical wall of the first cavity, improving the reliability of molding. Further, the first cavity is provided with clamping parts at its distal and proximal ends; the clamping part at the distal end fits with the corresponding part at the distal end of the rotating shaft, as described above, and the clamping part at the proximal end fits with the corresponding part at the proximal end of the rotating shaft, as described above, and the clamping part at the proximal end fits with the corresponding part at the proximal end of the rotating shaft, as described above, and the clamping part at the proximal end fits with the corresponding part at the proximal end of the rotating shaft, as described above, and the clamping part at the proximal end fits with the second positioning part. After the rotating shaft is placed within the first cavity, the clamping portion holds the distal and proximal ends of the rotating shaft for positioning. In some embodiments, the clamping portion can also separate the outer hub and the inner hub to prevent them from connecting at the distal end of the rotating shaft.

[0070] This disclosure provides a third aspect of a method for processing an impeller assembly (or an injection molding method), which is used to process an impeller assembly as described in any of the first aspects. In this method, a rotating shaft 1 and an injection mold as described in the above embodiments are first provided. The rotating shaft 1 has a hollow structure 11 along its axial direction X, and an injection opening 12 is provided on its sidewall. The rotating shaft 1 can be provided directly with the hollow structure 11 and the injection opening 12, or it can be processed to form a rotating shaft 1 with the hollow structure 11 and the injection opening 12. The injection opening 12 on the rotating shaft 1 can be matched with the root of the blade 22; specifically, the injection opening 12 can vary with the curvature and thickness of the blade 22 to improve the support effect on the blade 22. Then, the rotating shaft 1 is placed in the first cavity of the injection mold; the clamping part at the far end of the first cavity mates with the part of the rotating shaft that is not covered by the outer hub, and the clamping part at the near end of the first cavity mates with the part of the rotating shaft that is not covered by the outer hub, so as to achieve positioning of the rotating shaft. By accurately fixing the rotating shaft 1 in the first cavity of the injection mold, the impeller assembly is injection molded using the rotating shaft 1 as the core, so that the impeller 2 and the rotating shaft are fixed together by injection molding, improving the reliability of the impeller assembly after injection molding. Finally, injection molding material is injected into the hollow structure 11 of the rotating shaft 1, and the injection molding material sequentially passes through the hollow structure 11, the injection opening 12, the radial Y gap between the side wall of the rotating shaft 1 and the first cavity and enters the second cavity to form the impeller 2 by injection molding. High-temperature molten injection molding material is injected into the hollow structure 11 from the near end of the rotating shaft 1. The injection molding material passes through the hollow structure 11, the injection opening 12, the radial Y gap between the side wall of the rotating shaft 1 and the first cavity, and then enters the second cavity. After cooling, the injection molding material in the hollow structure 11 forms the inner hub 211, the injection molding material in the radial Y gap between the side wall of the rotating shaft and the first cavity forms the outer hub 212, and the injection molding material in the second cavity forms the blade 22. The inner hub 211, the outer hub 212, and the blade 22 form an integrated injection molding structure, which increases the connection strength between the hub 21 and the blade 22 in the axial X and radial Y directions, limits the relative position of the blade 22 with the rotating shaft 1 during high-speed rotation, and improves the reliability of the impeller assembly.

[0071] This disclosure provides a fourth aspect of a fluid pumping system, comprising a drive assembly and any of the aforementioned impeller assemblies, wherein the drive assembly drives the impeller assembly to pump fluid. For example, fluid is transported from a distal end to the fluid pumping system; the fluid entering the system is pressurized by a pressurization unit and then pumped out of the system at a higher dynamic pressure. Alternatively, at a target location, the fluid pumping system can be used to accelerate the fluid flow rate, for example, around a ventricular assist device. Further, the fluid pumping system also includes a pump head, comprising a pump housing and the impeller assembly described above, the impeller assembly being disposed within the pump housing. The drive assembly is connected to the rotating shaft of the impeller assembly and drives the rotating shaft to rotate.

[0072] The specific embodiments described above do not constitute a limitation on the scope of protection of this disclosure. Those skilled in the art, after considering the specification and practicing the technical solutions disclosed in this application, will readily conceive of other embodiments of this disclosure. This application is intended to cover any variations, uses, or adaptations of this disclosure that follow the general principles of this disclosure and include common knowledge or customary technical means in the art not disclosed in this disclosure. The specification and embodiments are considered exemplary only, and the true scope and spirit of this disclosure are indicated by the following claims.

[0073] It should be understood that this disclosure is not limited to the precise structures described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. The scope of this disclosure is limited only by the appended claims.

Claims

1. An impeller assembly, characterized in that: include: A rotating shaft with a hollowed-out structure along its axial direction; The hub is at least partially embedded in the hollow structure of the rotating shaft; The blade has its root connected to the hub and extends radially outward along the axis of rotation; At least one of the axial ends of the blade includes a reinforcing portion, which is disposed on the hub.

2. The impeller assembly according to claim 1, characterized in that, The radial dimension of the portion of the reinforcing part that is closer to the end of the adjacent rotating shaft is smaller.

3. The impeller assembly according to claim 1, characterized in that, The blade also includes a main body and a transition section, with the main body and the reinforcing section respectively connected to the two axial sides of the transition section; The radial dimension of the main body is greater than the radial dimension of the reinforcing part, and the radial dimension of the transition part is between the radial dimension of the main body and the radial dimension of the reinforcing part.

4. The impeller assembly according to claim 3, characterized in that, The outer contour curve of the transition portion is a convex shape away from the axis of rotation; and / or, the outer contour curve of the reinforcing portion is a concave shape close to the axis of rotation.

5. The impeller assembly according to claim 1, characterized in that, The blades can retract or expand relative to the axis of rotation.

6. The impeller assembly according to claim 1, characterized in that, The side wall of the rotating shaft has an injection molding opening that communicates with the hollow structure; The hub includes an inner hub and an outer hub. The inner hub is embedded in the hollow structure, and the outer hub at least partially covers the outer wall surface of the side wall of the rotating shaft. The inner hub and the outer hub are correspondingly connected to the injection opening. The root of the blade is connected to the outer hub.

7. The impeller assembly according to claim 6, characterized in that, The inner hub and the outer hub are integrally formed.

8. The impeller assembly according to claim 6, characterized in that, The inner hub, the outer hub, and the blades are integrally formed.

9. The impeller assembly according to claim 6, characterized in that, The hollow structure extends through the distal end of the rotating shaft along the axial direction, and the distal and proximal ends of the rotating shaft are at least partially not covered by the outer hub. The portion of the rotating shaft not covered by the outer hub at its distal end includes a first positioning part, and the portion of the rotating shaft not covered by the outer hub at its proximal end includes a second positioning part.

10. The impeller assembly according to claim 9, characterized in that, The first positioning part and the second positioning part are respectively configured to be adapted to the processing mold.

11. The impeller assembly according to claim 6, characterized in that, The distal end of the inner hub extends beyond the distal end of the hollow structure to form the hub end.

12. The impeller assembly according to claim 11, characterized in that, Along the direction from the proximal end to the distal end, the radial dimension of the hub end is gradually reduced to form a guide surface.

13. The impeller assembly according to any one of claims 1-5 or 7-12, characterized in that, The side wall of the rotating shaft has an injection molding opening that communicates with the hollow structure; The blade and the outer hub have a mating position; the extended shape of the injection opening matches the shape of the mating position.

14. A mold for processing the impeller assembly according to any one of claims 1 to 13, characterized in that, The mold has a forming cavity, which includes: A first cavity extends axially and is used to accommodate a rotating shaft, the first cavity being radially clearance-fitted with the rotating shaft; The second cavity is connected to the first cavity and extends radially by a predetermined distance from the sidewall of the first cavity. The cavity shape of the second cavity matches the blade, and the second cavity is used to form the blade.

15. The mold according to claim 14, characterized in that, The first cavity is provided with clamping parts at its distal and proximal ends respectively; The distal clamping portion mates with the corresponding portion at the distal end of the rotating shaft, and the proximal clamping portion mates with the corresponding portion at the proximal end of the rotating shaft.

16. A fluid pumping system, characterized in that, It includes a drive assembly and an impeller assembly as described in any one of claims 1 to 13, wherein the drive assembly drives the impeller assembly to operate in order to pump fluid.

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