Transcutaneous interventional axial flow blood pump

Abstract

The utility model belongs to the technical field of medical equipment, specifically discloses a kind of percutaneous intervention axial flow blood pump, comprising: driving component, driven transmission assembly, isolating bushing, shell and be set in the impeller in shell;Driven transmission assembly includes from magnetic steel sealingly installed in impeller, driving component includes main magnetic steel and drive source, main magnetic steel is installed in the output end of drive source, and sealingly installed in isolating bushing, isolating bushing is set between driving component and driven transmission assembly;Drive source drives main magnetic steel to drive from magnetic steel rotation, from magnetic steel drives impeller rotation.The utility model effectively improves the sealing of pump, avoids the power source of driving shaft to be damaged due to overload.

Description

Technical Field

[0001] This utility model belongs to the field of medical equipment technology, specifically relating to a percutaneous interventional axial flow blood pump. Background Technology

[0002] The percutaneous axial flow pump is a short-term percutaneous mechanical circulatory support device. Currently, it is mainly used to treat patients with acute aortic heart failure (ADHF) accompanied by cerebral vascular regeneration (CRS). Preclinical studies have shown that the pump, inserted via a delivery catheter through the femoral artery at the level of the descending aorta diaphragm, allows blood flow from the aorta to enter the pump. The pump accelerates this blood flow, increasing overall downward blood flow velocity, increasing renal artery perfusion, reducing proximal aortic resistance, increasing distal aortic flow, thereby reducing left ventricular afterload and improving cardiac output.

[0003] The core components of a pump mainly consist of a motor and an impeller, with the impeller's rotation powered by the motor. In existing technology, the motor transmits force via a contact coupling. Contact is required between the drive and driven shafts for force and torque transmission. When pumping blood, the blood contains corrosive substances such as hemoglobin and sodium chloride, and impurities are generated during motor operation. If these impurities mix with the blood, they can affect the patient. Therefore, the contact coupling uses a dynamic seal, but dynamic seals carry the risk of leakage. Furthermore, when the load torque on the driven shaft exceeds the maximum torque that the drive shaft can provide, the power source of the drive shaft (motor) is at risk of being damaged due to overload. Utility Model Content

[0004] The purpose of this invention is to provide a percutaneous interventional axial flow blood pump that effectively improves the pump's sealing performance and prevents the power source of the drive shaft from being damaged due to overload.

[0005] The purpose of this utility model is achieved through the following technical solution: a percutaneous interventional axial flow blood pump is provided, comprising: an active transmission assembly, a driven transmission assembly, an isolation sleeve, a housing, and an impeller disposed within the housing; the driven transmission assembly includes a driven magnet sealed and installed within the impeller, the active transmission assembly includes a main magnet and a drive source, the main magnet is installed at the output end of the drive source and sealed and installed within the isolation sleeve, the isolation sleeve being disposed between the active transmission assembly and the driven transmission assembly; the drive source drives the main magnet to rotate the driven magnet, and the driven magnet drives the impeller to rotate.

[0006] Operating based on the principle of magnetic coupling, the rotation of the active drive assembly generates a magnetic torque between it and the driven drive assembly, causing the driven magnet to rotate synchronously. The driven magnet then drives the driven shaft and impeller to rotate. The driven magnet is sealed within the impeller, and the active drive assembly is isolated from the blood via an isolation sleeve, preventing direct contact between the driven and main magnets and the blood. This reduces the corrosive and impact effects of the blood environment on the driven and main magnets, eliminating the risk of motor damage due to overload.

[0007] Preferably, the housing includes an end cap and an outer cover, one end of the outer cover being connected to the outside of the active drive assembly, and the end cap being installed at the other end of the outer cover.

[0008] Preferably, the isolation sleeve is provided with a third groove, and the driven transmission assembly further includes a driven shaft, which is installed in the impeller and is installed in the housing through a bearing assembly. The bearing assembly includes an end face bearing and an upper sliding bearing. The upper sliding bearing is disposed in the housing, and the end face bearing is disposed at the end of the impeller away from the active transmission assembly. One end of the driven shaft is disposed in the third groove, and the other end passes through the end face bearing and is connected to the upper sliding bearing.

[0009] Preferably, the isolation sleeve is provided with a third groove, and the driven transmission assembly further includes a driven shaft, which is installed in the impeller and is installed in the housing through a bearing assembly. The bearing assembly includes a bearing housing, a first lower sliding bearing and an upper sliding bearing. The upper sliding bearing is disposed in the housing, one end of the bearing housing is installed in the third groove, and the other end is connected to the first lower sliding bearing. One end of the driven shaft is disposed in the impeller, and the other end is connected to the upper sliding bearing.

[0010] Preferably, the driven transmission assembly further includes a driven shaft, which is installed in the impeller and is installed in the housing via a bearing assembly. The bearing assembly includes a second lower sliding bearing and an upper sliding bearing. The upper sliding bearing is disposed in the housing. One end of the second lower sliding bearing is connected to the isolation sleeve and the other end is connected to the driven magnet. One end of the driven shaft is disposed in the impeller and the other end is connected to the upper sliding bearing.

[0011] Preferably, it further includes a first sealing assembly, which includes a first cover plate and a first sealing ring. The impeller has a first groove and a second groove that communicate with each other. The first cover plate is disposed on the outside of the first groove, and the first sealing ring is disposed on the outside of the second groove.

[0012] Preferably, it further includes a second sealing assembly, which includes a second cover plate and a second sealing ring. A first lower sliding bearing is installed in the magnet to form an assembly. The second cover plate and the second sealing ring are respectively disposed at both ends of the assembly. The first lower sliding bearing, the second cover plate, the second sealing ring and the inner wall of the impeller form a sealing space for the magnet.

[0013] Preferably, a first gap of 0.1 to 0.25 mm is provided between the end face bearing and the upper sliding bearing.

[0014] Preferably, the bearing housing includes a disc portion and a protrusion extending axially outward from the center of the disc portion, the outer surface of the protrusion being composed of a plurality of outwardly convex and inwardly concave arc surfaces.

[0015] Preferably, the driven shaft is provided with a circular protrusion on the outer circumference near the end cover, the circular protrusion is connected to the tail end of the impeller, and the circular protrusion and the end cover are provided with a second gap of 0.1 to 0.25 mm.

[0016] Due to the adoption of the above technical solution, this utility model has the following advantages: The slave magnet seal is installed inside the impeller, while the main magnet seal is installed inside the isolation sleeve. This reduces the corrosion and impact of external environments, such as blood, on the slave and main magnets, thus delaying their aging and damage. Through the principle of magnetic coupling, force and torque can be transmitted between the drive shaft and the driven shaft without direct contact. When the load torque on the driven shaft exceeds the maximum torque that the magnetic coupling can transmit, the drive shaft and the driven shaft will automatically decouple, eliminating the risk of motor damage due to overload. Attached Figure Description

[0017] To more clearly illustrate the specific embodiments of this utility model, the accompanying drawings used in the specific embodiments will be briefly introduced below. In all the drawings, the elements or parts are not necessarily drawn to scale.

[0018] Figure 1 This is an exploded view of a percutaneous interventional axial flow blood pump according to the present invention; Figure 2 This is a schematic diagram of the outer casing; Figure 3 This is a schematic diagram of the end cap; Figure 4 This is a cross-sectional view of Embodiment 1; Figure 5 This is an exploded view of Example 2; Figure 6 This is a cross-sectional view of Example 2; Figure 7 This is an exploded view of Example 3; Figure 8 This is a cross-sectional view of Example 3; Figure 9 This is a schematic diagram of the impeller in Example 1; Figure 10 This is a schematic diagram of the isolation sleeve in Example 1; Figure 11 This is a schematic diagram of the isolation sleeve in Example 3; Figure 12 This is a schematic diagram of the second lower sliding bearing; Figure 13 This is a schematic diagram of the assembly of the isolation sleeve and the second lower sliding bearing; Figure 14 This is a schematic diagram of the bearing housing; Figure 15 The diagram shows the impellers for Embodiments 2 and 3.

[0019] Figure label: 1-Active drive assembly, 11-Second step, 12-Motor, 13-Drive shaft, 14-Main magnet, 15-Second sealed space; 2-Driven transmission assembly, 21-Driven shaft, 211-Annular protrusion, 22-Driven magnet, 23-Magnet protection ring; 3-Isolation sleeve, 31-First step, 32-Third groove, 33-First boss; 4-Impeller, 41-Mounting cavity, 42-First groove, 43-Second groove, 44-First sealing space, 45-Liquid inlet; 5-Outer shell, 51-Inlet, 52-Outlet, 53-End cap, 531-Upper sliding bearing hole, 54-Outer cover; 6-Sealing assembly, 61-First cover plate, 62-First sealing ring, 63-Second cover plate, 64-Second sealing ring, 65-Third cover plate, 66-Third sealing ring; 7-Bearing assembly, 71-End face bearing, 72-Upper sliding bearing, 73-Bearing housing, 731-Disc portion, 732-Protrusion, 74-First lower sliding bearing, 75-Second lower sliding bearing, 751-Mounting portion, 752-Second boss; 8 - First gap, 9 - Second gap. Detailed Implementation

[0020] The embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0021] Please see Figures 1 to 4A percutaneous axial flow blood pump includes: an active drive assembly 1, a driven drive assembly 2, an isolation sleeve 3, a housing 5, and an impeller 4 disposed within the housing 5. The driven drive assembly 2 includes a driven magnet 22 sealed within the impeller 4. The active drive assembly 1 includes a main magnet 14 and a drive source. The main magnet 14 is mounted at the output end of the drive source and sealed within the isolation sleeve 3, which is disposed between the active drive assembly 1 and the driven drive assembly 2. The drive source drives the main magnet 14 to rotate the driven magnet 22, which in turn drives the impeller 4 to rotate. Specifically, the active drive assembly 1 further includes an active shaft 13. The drive source is preferably a motor 12, the output end of which is connected to the active shaft 13. The main magnet 14 is fixedly mounted on the outside of the active shaft 13 and disposed within the isolation sleeve 3. One end of the isolation sleeve 3 is sealed to the motor 12, and the other end is connected to the housing 5. The outer side of the outer casing 5 is provided with several outlets 52 evenly spaced circumferentially. One side surface of the outer casing 5 is provided with an inlet 51 communicating with the outlets 52. A portion of the blood in the aorta flows into the pump from the inlet 51. The blood flowing into the pump is accelerated by the impeller 4 and flows out of the pump from the outlet 52 in the form of a high-speed jet. The high-speed blood flow carries blood from outside the pump together, which accelerates the overall blood flow in the aorta and increases the blood volume. The end of the isolation sleeve 3 facing the driven transmission component 2 is provided with a first step 31. The outer casing 5 is mounted on the isolation sleeve 3 through the first step 31. One end of the motor 12 is provided with a second step 11. The motor 12 can be glued to the outer surface of the second step 11, or through an interference fit, or by any of the existing installation methods, so that the active transmission component 1 and the isolation sleeve 3 are sealed together. The isolation sleeve 3 is disposed between the active transmission component 1 and the driven transmission component 2. The isolation sleeve 3 and the motor 12 form a second sealed space 15, and the main magnet 14 is located inside the second sealed space 15.

[0022] This invention relates to a percutaneous axial flow blood pump, in which a motor 12 provides power and drives a drive shaft 13 to rotate, which in turn drives a main magnet 14 to rotate. Through magnetic coupling, force and torque transmission between the drive assembly 1 and the driven assembly 2 is achieved without direct contact. The main magnet 14 and the driven magnet 22 are installed using static sealing, resulting in a better seal than existing dynamic seals. Operating according to the magnetic coupling principle, after the drive assembly 1 rotates, a magnetic torque is generated between the main magnet 14 and the driven magnet 22, causing the driven magnet 22 to rotate synchronously. The driven magnet 22 then drives an impeller 4 to rotate. Blood enters through the inlet 51, is guided by the rotating impeller 4 to move in a predetermined direction, and exits through the outlet 52. The driven magnet 22 is sealed and installed inside the impeller 4. The active drive assembly 1 is isolated from blood or gas by the isolation sleeve 3, preventing blood from directly acting on the surface of the driven magnet 22 or the main magnet 14, thereby reducing the corrosion and impact on the driven magnet 22 and the main magnet 14, and delaying the aging and damage of the driven magnet 22 and the main magnet 14. When the load torque on the driven drive assembly 2 exceeds the maximum torque that the magnetic coupling can transmit, the active drive assembly 1 and the driven drive assembly 2 will automatically decouple (no torque transmission between the master and slave), eliminating the risk of damage to the power source of the drive shaft 13 due to overload.

[0023] Further, please refer to Figures 1 to 3 The outer casing 5 includes an end cap 53 and an outer cover 54. One end of the outer cover 54 is connected to the outside of the active transmission assembly 1, and the end cap 53 is installed at the other end of the outer cover 54. Specifically, the outer cover 54 has a plurality of outlets 52 evenly spaced along its circumference on its outer side, and one end of the outer cover 54 is sealed to the first step 31 by adhesive. The end cap 53 is installed at one end of the outer cover by adhesive or interference fit, and the surface of the end cap 53 has a plurality of perforated grooves evenly spaced along its circumference, which serve as blood inlets 51.

[0024] Example 1 Further, please refer to Figure 1 , Figure 3 , Figure 4 , Figure 9 and Figure 10The isolation sleeve 3 is provided with a third groove 32. The driven transmission assembly 2 also includes a driven shaft 21, which is installed in the impeller 4 and is installed in the housing 5 through a bearing assembly 7. The bearing assembly 7 includes an end face bearing 71 and an upper sliding bearing 72. The upper sliding bearing 72 is disposed in the housing 5, and the end face bearing 71 is disposed at the end of the impeller 4 away from the driving transmission assembly 1. One end of the driven shaft 21 is disposed in the third groove 32, and the other end passes through the end face bearing 71 and is connected to the upper sliding bearing 72. Specifically, the impeller 4 is provided with a mounting cavity 41 for mounting the driven shaft 21. The first groove 42 and the second groove 43 communicate with the mounting cavity 41. One end of the driven shaft 21 is fixedly installed in the impeller 4, and the other end is connected to the upper sliding bearing 72. The outer side of the driven shaft 21 is provided with a step that cooperates with the sealing assembly 6 and the impeller 4. The isolation sleeve 3 has a third groove 32 at its shaft center, and the end cover 53 has an upper sliding bearing hole 531 at its shaft center, with the upper sliding bearing 72 disposed in the upper sliding bearing hole 531. One end of the driven shaft 21 is disposed in the third groove 32, and the other end is disposed in the upper sliding bearing 72. The end face bearing 71 is a sealed bearing, disposed on the outer side of the driven shaft 21 near the end cover 53, and the end face bearing 71 further seals the first sealing space 44.

[0025] Further, please refer to Figure 4 A first gap 8 of 0.1–0.25 mm is provided between the end face bearing 71 and the upper sliding bearing 72. With this structure, the driven transmission assembly 2 is provided with axial displacement space during operation. When the impeller 4 is transporting blood, the blood flows through the first gap 8 to the upper sliding bearing 72, lubricating it. This blood lubrication reduces the frictional force generated by the relative movement between the end face bearing 71 and the sliding bearing 72, and between the driven shaft 21 and the upper sliding bearing 72. Simultaneously, the flow of blood carries away the heat generated by friction, preventing localized overheating. The first gap 8 has a spacing value of 0.1–0.25 mm. When the first gap is greater than 0.25 mm, it cannot effectively limit the axial movement of the driven transmission assembly 2; when it is less than 0.1 mm, the lubrication effect will be poor. Preferably, the first gap 8 is 0.2 mm, which can effectively limit the axial movement of the driven shaft 21 while providing good lubrication.

[0026] Further, please refer to Figure 1 and Figure 4The device also includes a first sealing assembly 6, which includes a first cover plate 61 and a first sealing ring 62. The impeller 4 has a communicating first groove 42 and a second groove 43. The first cover plate 61 is disposed on the outside of the first groove 42, and the first sealing ring 62 is disposed on the outside of the second groove 43. Specifically, the first cover plate 61 is installed on the outside of the first groove 42 by adhesive, and the first sealing ring 62 is installed on the outside of the second groove 43 by adhesive. The first cover plate 61, the first sealing ring 62, and the inner wall of the first groove 42 form a first sealing space 44. The magnet 22 is located in the first sealing space 44, and the first cover plate 61 seals and limits the movement of the magnet 22.

[0027] Example 2 Further, please refer to Figure 5 , Figure 6 and Figure 14 The isolation sleeve 3 is provided with a third groove 32. The driven transmission assembly 2 also includes a driven shaft 21, which is installed in the impeller 4 and is installed in the housing 5 via a bearing assembly 7. The bearing assembly 7 includes a bearing seat 73, a first lower sliding bearing 74, and an upper sliding bearing 72. The upper sliding bearing 72 is disposed in the housing 5. One end of the bearing seat 73 is installed in the third groove 32, and the other end is connected to the first lower sliding bearing 74. One end of the driven shaft 21 is disposed in the impeller 4, and the other end is connected to the upper sliding bearing 72. Specifically, the impeller 4 is provided with a mounting cavity 41 for mounting the driven shaft 21. One end of the driven shaft 21 is fixedly installed in the impeller 4 by an interference fit, and the other end is connected to the upper sliding bearing 72, which is disposed in the end cover 53. The bearing seat 73 includes a disc portion 731 and a protrusion 732 extending axially outward from the center of the disc portion. The outer surface of the protrusion is composed of several outwardly convex and inwardly concave arc surfaces. The disc portion 731 is installed within the third groove 32, and the protrusion 732 abuts against the inner wall of the first lower sliding bearing 74. With this structure, the bearing seat 73 can reduce the contact area with the first lower sliding bearing 74, thereby reducing frictional loss. Preferably, there are three protrusions, and the inner recesses and protrusions are smoothly connected by arc segments.

[0028] Further, please refer to Figure 6 and Figure 15The assembly also includes a second sealing component, which comprises a second cover plate 63 and a second sealing ring 64. A first lower sliding bearing 74 is mounted in the secondary magnet 22 to form an assembly. The second cover plate 63 and the second sealing ring 64 are respectively disposed at both ends of the assembly. The first lower sliding bearing 74, the second cover plate 63, the second sealing ring 64, and the inner wall of the impeller 4 constitute a sealing space for the secondary magnet 22. Specifically, the inner side of the first lower sliding bearing 74 is clearance-fitted with the outer side of the bearing seat 73, and the outer side is installed in the shaft hole of the secondary magnet 22 by adhesive bonding or by interference fit. After assembly, both ends are sealed by the second cover plate 63 and the second sealing ring 64 by adhesive bonding. Therefore, the secondary magnet 22 is sealed in the space formed by the second cover plate 63, the first lower sliding bearing 74, the second sealing ring 64, and the inner wall of the impeller 4. With this structure, multiple liquid inlets 45 can be set on the outside of the impeller. During operation, blood enters through the liquid inlets 45. Since the bearing housing 73 and the first lower sliding bearing 74 are clearance fit, the blood flows between the bearing housing 73 and the first lower sliding bearing 74 and then enters the outer casing 5 for discharge. During this process, the blood lubricates the bearing housing 73 and the first lower sliding bearing 74, reducing the friction generated by their relative movement. At the same time, the flow of blood carries away the heat generated by friction, avoiding local overheating.

[0029] Example 3 Further, please refer to Figure 7 , Figure 8 , Figure 11 , Figure 12 and Figure 13The implementation method of this embodiment is basically the same as that of Embodiment 2, except that the structure of the isolation sleeve 3 is different. Specifically, the driven transmission assembly 2 also includes a driven shaft 21, which is installed in the impeller 4 and is installed in the housing 5 through a bearing assembly 7. The bearing assembly 7 includes a second lower sliding bearing 75 and an upper sliding bearing 72. The upper sliding bearing 72 is disposed in the housing 5. One end of the second lower sliding bearing 75 is connected to the isolation sleeve 3, and the other end is connected to the driven magnet 22. One end of the driven shaft 21 is disposed in the impeller 4, and the other end is connected to the upper sliding bearing 72. Specifically, the impeller 4 is provided with a mounting cavity 41 for mounting the driven shaft 21. One end of the driven shaft 21 is fixedly mounted in the impeller 4 by interference fit or adhesive, and the other end is connected to the upper sliding bearing 72. The outer end face of the isolation sleeve 3 is provided with a plurality of first protrusions 33, which are spaced apart circumferentially. The inner wall of one end of the second lower sliding bearing 75 is provided with a second boss 752 that mates with the first boss 33. The inner wall of the second boss 752 is clearance-fitted with the outer side of the first boss 33. Preferably, there are three first bosses 33. This structure can reduce the contact area, reduce friction, and thus reduce the loss and heat generated by friction. Furthermore, it also includes a third sealing assembly, which includes a third cover plate 65, a third sealing ring 66, and a magnet protective ring 23. The magnet protective ring 23 is installed in the shaft hole of the magnet 22 by interference fit or adhesive, and after assembly, it forms an assembly. The other end of the second lower sliding bearing 75 is provided with a mounting part 751. The third cover plate 65, the assembly, and the third sealing ring 66 are installed sequentially from the mounting part 751 to the first groove 42. Therefore, the magnet 22 is sealed in the space formed by the third cover plate 65, the magnet protective ring 23, the third sealing ring 66, the inner wall of the impeller 4, and the inner wall of the second lower sliding bearing 75. With this structure, multiple liquid inlets 45 can be set on the outside of the impeller. During operation, blood enters through the liquid inlets 45. Since the second lower sliding bearing 75 and the isolation sleeve 3 are clearance fit, the blood flows between the second lower sliding bearing 75 and the isolation sleeve 3 and then enters the outer casing 5 for discharge. During this process, the blood lubricates the second lower sliding bearing 75 and the isolation sleeve 3, reducing the friction generated by their relative movement. At the same time, the flow rate carries away the heat generated by friction, avoiding local overheating.

[0030] Further, please refer to Figure 6 and Figure 8 In Embodiments 2 and 3, a circular protrusion 211 is provided circumferentially on the outer side of the driven shaft 21 near the end cover 53. The circular protrusion 211 is connected to the tail end of the impeller 4, and a second gap 9 of 0.1 to 0.25 mm is provided between the circular protrusion 211 and the end cover 53. Specifically, the circular protrusion 211 is installed at the rear end of the mounting cavity 41 by interference fit or adhesive bonding. The function and principle of the second gap 9 are the same as the first gap 8 in Embodiment 1.

[0031] This utility model discloses a percutaneous axial flow blood pump. The driven magnet 22 is sealed within the impeller 4 via a sealing assembly, while the main magnet 14 is sealed within a second sealing space 15. This prevents blood from corroding and impacting the driven and main magnets 22 and 14, thus delaying their aging and damage. Utilizing the principle of magnetic coupling, force and torque transmission between the drive shaft 13 and driven shaft 21 can be achieved without direct contact, making it suitable for blood transport applications. A first gap 8 and a second gap 9 are provided. When the impeller 4 is transporting blood, the blood flows through the gaps to the upper sliding bearing 72, lubricating it and reducing friction and heat generated by the rotation of the upper sliding bearing 72. The percutaneous axial flow blood pump employs various structures, allowing selection based on different application scenarios.

[0032] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of this utility model. It should be understood that the above description is only a specific embodiment of this utility model and is not intended to limit this utility model. Any modifications, equivalent substitutions, and improvements made within the scope of the spirit of this utility model should be included within the protection scope of this utility model.

Claims

1. A percutaneous interventional axial flow blood pump, characterized in that, include: The active drive assembly (1), the driven drive assembly (2), the isolation sleeve (3), the housing (5), and the impeller (4) disposed in the housing (5); the driven drive assembly (2) includes a driven magnet (22) sealed and installed in the impeller (4), the active drive assembly (1) includes a main magnet (14) and a drive source, the main magnet (14) is installed at the output end of the drive source and sealed and installed in the isolation sleeve (3), the isolation sleeve (3) is disposed between the active drive assembly (1) and the driven drive assembly (2); the drive source drives the main magnet (14) to drive the driven magnet (22) to rotate, and the driven magnet (22) drives the impeller (4) to rotate.

2. The percutaneous axial flow blood pump according to claim 1, characterized in that, The housing (5) includes an end cap (53) and an outer cover (54). One end of the outer cover (54) is connected to the outside of the active drive assembly (1), and the end cap (53) is installed at the other end of the outer cover (54).

3. The percutaneous axial flow blood pump according to claim 2, characterized in that, The isolation sleeve (3) is provided with a third groove (32). The driven transmission assembly (2) also includes a driven shaft (21). The driven shaft (21) is installed in the impeller (4), and the driven shaft (21) is installed in the end cover (53) through the bearing assembly (7). The bearing assembly (7) includes an end face bearing (71) and an upper sliding bearing (72). The upper sliding bearing (72) is located in the end cover (53). The end face bearing (71) is located at one end of the impeller (4) away from the active transmission assembly (1). One end of the driven shaft (21) is located in the third groove (32), and the other end passes through the end face bearing (71) and is connected to the upper sliding bearing (72).

4. The percutaneous axial flow blood pump according to claim 2, characterized in that, The isolation sleeve (3) is provided with a third groove (32). The driven transmission assembly (2) also includes a driven shaft (21). The driven shaft (21) is installed in the impeller (4), and the driven shaft (21) is installed in the end cover (53) through the bearing assembly (7). The bearing assembly (7) includes a bearing seat (73), a first lower sliding bearing (74), and an upper sliding bearing (72). The upper sliding bearing (72) is disposed in the end cover (53). One end of the bearing seat (73) is installed in the third groove (32), and the other end is connected to the first lower sliding bearing (74). One end of the driven shaft (21) is disposed in the impeller (4), and the other end is connected to the upper sliding bearing (72).

5. The percutaneous axial flow blood pump according to claim 2, characterized in that, The driven transmission assembly (2) also includes a driven shaft (21), which is installed in the impeller (4) and is installed in the end cover (53) via a bearing assembly (7). The bearing assembly (7) includes a second lower sliding bearing (75) and an upper sliding bearing (72). The upper sliding bearing (72) is located in the end cover (53). One end of the second lower sliding bearing (75) is connected to the isolation sleeve (3) and the other end is connected to the driven magnet (22). One end of the driven shaft (21) is located in the impeller (4) and the other end is connected to the upper sliding bearing (72).

6. The percutaneous axial flow blood pump according to claim 3, characterized in that, It also includes a first sealing assembly (6), which includes a first cover plate (61) and a first sealing ring (62). The impeller (4) is provided with a first groove (42) and a second groove (43) that are connected. The first cover plate (61) is located on the outside of the first groove (42), and the first sealing ring (62) is located on the outside of the second groove (43).

7. The percutaneous axial flow blood pump according to claim 4, characterized in that, It also includes a second sealing assembly, which includes a second cover plate (63) and a second sealing ring (64). A first lower sliding bearing (74) is installed in the magnet (22) to form an assembly. The second cover plate (63) and the second sealing ring (64) are respectively disposed at both ends of the assembly. The first lower sliding bearing (74), the second cover plate (63), the second sealing ring (64) and the inner wall of the impeller (4) form a sealing space for the magnet (22).

8. The percutaneous axial flow blood pump according to claim 3, characterized in that, A first gap (8) of 0.1 to 0.25 mm is provided between the end face bearing (71) and the upper sliding bearing (72).

9. The percutaneous axial flow blood pump according to claim 4, characterized in that, The bearing housing (73) includes a disc portion (731) and a protrusion (732) extending outward along the axial direction from the center of the disc portion. The outer surface of the protrusion (732) is composed of several outwardly convex and inwardly concave arc surfaces.

10. The percutaneous axial flow blood pump according to claim 4, 5 or 9, characterized in that, The driven shaft (21) has a circular protrusion (211) on the outer circumferential side near the end cover (53). The circular protrusion (211) is connected to the tail end of the impeller (4), and the circular protrusion (211) and the end cover (53) have a second gap (9) of 0.1 to 0.25 mm.

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