A magnetically suspended blood pump

Abstract

The present invention provides a magnetic suspension blood pump, including a mounting seat, a pump casing and an impeller, wherein the inner rotor magnetic ring on the peripheral wall of the impeller is magnetically coupled with the outer rotor magnetic ring in the mounting seat to form an axial support system; the dynamic magnetic ring on the peripheral wall of the impeller and the static magnetic ring on the inner wall of the pump casing form a group of radial passive magnetic bearings that repel each other, and the first axial magnetic ring at the bottom of the impeller and the second axial magnetic ring in the mounting seat form a group of radial passive magnetic bearings that attract each other. Both the axial support system and the radial support system are passive magnetic bearings that rely on the magnetic force of permanent magnets to achieve magnetic suspension, so there is no need to set up an active control system (sensor, controller, electromagnet, etc.), so the energy consumption is low and the cost is low.

Description

Technical Field

[0001] The present invention relates to the field of ventricular assist technology, and in particular to a magnetically suspended blood pump. Background Art

[0002] Blood pumps are divided into implantable, extracorporeal and interventional types. Centrifugal blood pump technology is mostly used for implantable and extracorporeal blood pumps. After three generations of technology evolution, the third-generation magnetic levitation blood pump is recognized as the centrifugal blood pump with the best blood compatibility. The magnetic levitation blood pump uses a magnetic levitation system to suspend the impeller inside the pump in the pump casing to avoid blood cell damage caused by mechanical bearing friction, thereby achieving better blood compatibility. The design of a blood pump is usually a balance between blood compatibility and hydraulic performance, and factors that affect blood compatibility include the shear stress that the blood is subjected to and the length of time it is exposed to shear stress.

[0003] Magnetic suspension bearings achieve rotor suspension by energizing electromagnetic coils to generate electromagnetic force. According to Earnshaw theory, stable passive suspension cannot be achieved by permanent magnets alone. To maintain the stability of the system, at least one direction of movement must be actively controlled. Therefore, existing magnetic suspension blood pumps all have an active control system, including sensors, controllers, electromagnets, etc. This inevitably brings a series of problems such as large size and high energy consumption, which largely restricts the development of magnetic suspension blood pumps. Summary of the invention

[0004] The present invention provides a magnetic suspension blood pump which does not require an active control system and has good stability.

[0005] In order to achieve the above-mentioned purpose, the technical solution adopted by the present invention is: a magnetic levitation blood pump, including a mounting seat, a pump casing and an impeller, the inner rotor magnetic ring on the peripheral wall of the impeller is magnetically coupled with the outer rotor magnetic ring in the mounting seat to form an axial support system; the dynamic magnetic ring on the peripheral wall of the impeller and the static magnetic ring on the inner wall of the pump casing form a group of repelling radial passive magnetic bearings, and the first axial magnetic ring at the bottom of the impeller and the second axial magnetic ring in the mounting seat form a group of attractive radial passive magnetic bearings.

[0006] A driving unit is arranged in the mounting seat, and the driving unit includes a rotating shaft, a magnetic steel is fixed on the shaft body of the rotating shaft, a stator coil is arranged on the outer periphery of the magnetic steel, and a bearing is arranged at each end of the rotating shaft. The second axial magnetic ring is fixed on the rotating shaft near the bottom of the impeller and leaves a gap with the bottom of the pump casing.

[0007] A rotating body is extended from the end of the rotating shaft and the two are arranged coaxially. The rotating body as a whole is in the shape of a barrel with its opening facing the impeller. The outer rotor magnetic ring is fixed on the inner wall of the barrel, the pump casing is placed in the barrel, and an inner rotor magnetic ring is fixed on the outer peripheral wall of the impeller at a position corresponding to the outer rotor magnetic ring.

[0008] The second axial magnetic ring is embedded in the rotating shaft, the end face of the second axial magnetic ring is flush with the barrel bottom of the rotating body and is coaxially arranged with the rotating shaft and the second axial magnetic ring; the first axial magnetic ring is embedded in the bottom of the impeller, the end face of the first axial magnetic ring is flush with the bottom of the impeller and the first axial magnetic ring is coaxially arranged with the impeller; preferably, the second axial magnetic ring is coaxially arranged with the first axial magnetic ring and has the same diameter.

[0009] The dynamic magnetic ring is arranged on the peripheral wall of the impeller located outside the rotating body, and the static magnetic ring is arranged on the inner wall of the pump casing corresponding to the position of the dynamic magnetic ring.

[0010] The first axial magnetic ring and the second axial magnetic ring are axially magnetized magnetic ring structures, and different magnetic poles are arranged adjacent to each other to attract each other; the inner rotor magnetic ring and the outer rotor magnetic ring are radially magnetized multi-stage permanent magnetic tiles or soft magnet structures, and different magnetic poles are arranged adjacent to each other to achieve synchronous rotation and axial limitation of the two; the dynamic magnetic ring and the static magnetic ring are axially magnetized permanent magnets, and the same magnetic poles are arranged adjacent to each other to support the radial balance and suspension of the impeller.

[0011] An inner rotor sleeve is provided on the impeller shaft, which completely wraps the shaft, the inner rotor magnetic ring and the first axial magnetic ring to form a sealed fit. The pump casing includes an upper shell and an isolation sleeve, and the two are sealed and connected. The impeller is arranged in a chamber enclosed by the upper shell and the isolation sleeve.

[0012] The impeller comprises a plurality of long blades and a plurality of short blades, and the long blades and the short blades are alternately arranged on the wheel disc and spirally surround the wheel disc; preferably, one long blade and one short blade form a blade group.

[0013] There are multiple blade groups arranged evenly on the wheel disc. The head end of the blade is arc-shaped and the tail has an inclined guide portion. The rotation angle between the head and tail of the short blade is α, and the rotation angle between the head and tail of the long blade is β, wherein α<β<2α.

[0014] A concave cavity is provided in the mounting seat, and the pump casing is placed in the concave cavity to form a fixed connection, and a closed structure is formed between the pump casing and the mounting seat. The upper shell is provided with a liquid inlet pipe and a liquid outlet pipe, wherein the liquid inlet pipe is consistent with the axial direction of the impeller, and the liquid outlet pipe is arranged on the side of the upper shell, and a guide cone column is provided in the middle part of the wheel disc protruding toward the inner cavity of the liquid inlet pipe, and the flow channel in the upper shell is an annular flow channel or a spiral flow channel.

[0015] In the above scheme, both the axial support system and the radial support system are passive magnetic bearings, which rely on the magnetic force of permanent magnets to achieve magnetic suspension. Therefore, there is no need to set up an active control system (sensor, controller, electromagnet, etc.), so the energy consumption is low and the cost is low. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a schematic diagram of the structure of a magnetically suspended blood pump;

[0017] Figure 2 for Figure 1 Schematic diagram of magnetization direction of each magnet;

[0018] Figure 3 It is a schematic diagram of the structure of the pump casing;

[0019] Figure 4 is a schematic diagram of the structure of the impeller;

[0020] Figure 5 It is a schematic diagram of the structure of the mounting base and the driving unit;

[0021] Figure 6 is a three-dimensional diagram of the impeller;

[0022] Figure 7 is a top view of the impeller;

[0023] Figure 8a It is a schematic diagram of the structure of the upper shell of the spiral flow channel;

[0024] Figure 8b It is a schematic diagram of the structure of the upper shell of the annular flow channel;

[0025] Fig. 9 It is a comparison diagram of flow field velocity vector distribution simulation in Example 1 and Example 2;

[0026] Fig.10 This is a comparison diagram of the impeller wall shear stress simulation in Example 1 and Example 2;

[0027] Fig.11 It is a comparison diagram of the head-flow curve in Example 1 and Example 2;

[0028] Fig.12 It is a comparison diagram of the pressure distribution simulation in Example 1 and Example 2. DETAILED DESCRIPTION

[0029] The following is combined with Figure 1-12 The present invention is described in further detail.

[0030] like Figure 1 As shown, a magnetic levitation blood pump includes a mounting seat 10, a pump casing 20 and an impeller 30. The inner rotor magnetic ring A1 on the peripheral wall of the impeller 30 is magnetically coupled with the outer rotor magnetic ring A2 in the mounting seat 10 to form an axial support system; the dynamic magnetic ring B1 on the peripheral wall of the impeller 30 and the static magnetic ring B2 on the inner wall of the pump casing 20 form a group of repelling radial passive magnetic bearings, and the first axial magnetic ring C1 at the bottom of the impeller 30 and the second axial magnetic ring C2 in the mounting seat 10 form a group of attractive radial passive magnetic bearings.

[0031] The power source for the rotation of the impeller 30 comes from the inner rotor magnetic ring A1 and the outer rotor magnetic ring A2. The power drives the outer rotor magnetic ring A2 to rotate. Under the action of magnetic coupling, the outer rotor magnetic ring A2 drives the inner rotor magnetic ring A1 to rotate, and then drives the entire impeller 30 to rotate together. The magnetic suspension movement of the inner rotor magnetic ring A1 drives the blood from the inlet to the outlet of the pump housing 20, completing a continuous blood pumping cycle. The inner rotor magnetic ring A1 and the outer rotor magnetic ring A2 not only serve as magnetic coupling power transmission components, but also play the role of axial positioning support to ensure the stability of the axial position of the impeller 30. The stability of the radial position of the impeller 30 is achieved by relying on two sets of magnetic bearings, that is, the dynamic magnetic ring B1 and the static magnetic ring B2 constitute a set of radial passive magnetic bearings that repel each other, and the first axial magnetic ring C1 and the second axial magnetic ring C2 constitute a set of radial passive magnetic bearings that attract each other. When the speed of the impeller 30 reaches a certain value, the entire impeller 30 will find its own bowl-shaped potential energy minimum point at a specific point, thereby generating a stable movement of complete magnetic suspension.

[0032] In the above scheme, both the axial support system and the radial support system are passive magnetic bearings, which completely rely on the magnetic force of permanent magnets to achieve magnetic suspension. Therefore, there is no need to set up an active control system (sensor, controller, electromagnet, etc.), with low energy consumption and low cost.

[0033] See also Figure 5 , a drive unit 40 is arranged in the mounting seat 10, and the drive unit 40 includes a rotating shaft 41, a magnetic steel 42 is fixed on the shaft body of the rotating shaft 41, a stator coil 43 is arranged on the outer periphery of the magnetic steel 42, and a bearing 44 is arranged at each end of the rotating shaft 41, and the second axial magnetic ring C2 is fixed on the rotating shaft 41 near the bottom of the impeller 30 and has a gap with the bottom of the pump housing 20. The bearing 44 is a high-precision standard ball bearing, which adopts a self-lubricating closed ball bearing with internal grease. Under normal working conditions, the maximum long-term stable operating temperature of the bearing does not exceed 95°C, and the rated service life is not less than 25,000 hours. It should be emphasized here that the second axial magnetic ring C2 is fixed on the rotating shaft 41, so it will rotate with the rotation of the rotating shaft 41, that is, the second axial magnetic ring C2 is not fixed, and the rotating second axial magnetic ring C2 will introduce a certain amount of power to the entire radial support system, improve the energy transfer efficiency, and thus improve the hydraulic performance of the blood pump.

[0034] In order to realize the rotation of the outer rotor magnetic ring A2, a rotating body 45 is extended from the end of the rotating shaft 41 and the two are arranged coaxially. The rotating body 45 is in the shape of a barrel with its opening facing the impeller 30. The outer rotor magnetic ring A2 is fixed on the inner wall of the barrel, and the pump housing 20 is partially placed in the barrel, and the inner rotor magnetic ring A1 is fixed on the outer peripheral wall of the impeller 30 at the position corresponding to the outer rotor magnetic ring A2. The setting of the rotating body 45 provides installation space for the setting of the pump housing 20 on the one hand, and enables the outer rotor magnetic ring A2 to rotate on the outer periphery of the inner rotor magnetic ring A1 on the other hand, while the end faces of the first axial magnetic ring C1 and the second axial magnetic ring C2 are aligned to ensure the utilization efficiency of the magnetic force. The shaft core of the rotating body 45 preferably coincides with the axis of the rotating shaft 41, thereby improving the stability of the movement of the impeller 30.

[0035] In order to reduce the size of the entire blood pump, the second axial magnetic ring C2 is embedded in the rotating shaft 41, and the end surface of the second axial magnetic ring C2 is flush with the barrel bottom of the rotating body 45 and is coaxially arranged with the rotating shaft 41 and the second axial magnetic ring C2. In this way, the axial size of the blood pump is minimized while ensuring that the second axial magnetic ring C2 can rotate synchronously with the rotating shaft 41.

[0036] Similarly, the first axial magnetic ring C1 is embedded in the bottom of the wheel shaft 31 of the impeller 30, the end face of the first axial magnetic ring C1 is flush with the bottom of the impeller 30, and the first axial magnetic ring C1 is coaxially arranged with the impeller 30. It has been explained above that the axis of the rotating body 45 coincides with the rotating shaft 41, so the second axial magnetic ring C2 is located at the center of the rotating body 45, and the first axial magnetic ring C1 is also arranged at the center of the impeller 30, which can be used together with the yoke of the matching soft magnet, and is fastened to the axial center threaded hole of the wheel shaft 31 by the fastening screw. The second axial magnetic ring C2 can be used together with the yoke of the matching soft magnet, and is fixed to the axial center threaded hole of the rotating shaft 31 by the fastening screw. The second axial magnetic ring C2 interacts with the first axial magnetic ring C1 to ensure that the impeller 30 always rotates at the center line position of the rotating body 45, prevents it from being offset, and improves the stability of the magnetic suspension motion. Preferably, the second axial magnetic ring C2 is coaxially arranged with the first axial magnetic ring C1 and has the same diameter. It needs to be explained that it is an ideal state that the second axial magnetic ring C2 is coaxial with the first axial magnetic ring C1. During the normal suspension and rotation of the impeller 30, it is inevitable that there will be a movement trend of left and right deflection and centerline tilt. At this time, the interacting end faces of the second axial magnetic ring C2 and the first axial magnetic ring C1 can be corrected in time, so that the end faces of the second axial magnetic ring C2 and the first axial magnetic ring C1 are exactly opposite to each other, thereby ensuring that the impeller 30 is suspended in the center position as much as possible.

[0037] In order to avoid magnetic interference between the magnetic rings, the dynamic magnetic ring B1 is arranged on the peripheral wall of the axle 31 of the impeller 30 located outside the rotating body 45, and the static magnetic ring B2 is arranged on the inner wall of the pump housing 20 corresponding to the position of the dynamic magnetic ring B1. It is preferred to arrange a magnetic isolation component between them to prevent magnetic interference. The dynamic magnetic ring B1 is arranged outside the rotating body 45, on the one hand, to prevent it from interfering with the interaction between the inner rotor magnetic ring A1 and the outer rotor magnetic ring A2, and on the other hand, to ensure that it can better interact with the static magnetic ring B2 on the inner wall of the pump housing 20.

[0038] like Figure 2 As shown, the first axial magnetic ring C1 and the second axial magnetic ring C2 are axially magnetized magnetic ring structures, and different magnetic poles are arranged adjacently to attract each other, and at the same time, they play a certain radial correction role due to the end face effect; the inner rotor magnetic ring A1 and the outer rotor magnetic ring A2 are radially magnetized multi-stage permanent magnetic tiles or soft magnetic magnet structures, and different magnetic poles are arranged adjacently to achieve synchronous rotation and axial limit of the two; the dynamic magnetic ring B1 and the static magnetic ring B2 are axially magnetized permanent magnets, and the same magnetic poles are arranged adjacently to support the radial balance and suspension of the impeller 30. In simple terms, radial magnetization is magnetization in the diameter direction, and axial magnetization is magnetization in the vertical direction. The magnets obtained in different magnetization directions have different functions, and the arrangement of the two sets of magnetic poles will also play different roles. From the above content, it can be seen that through the arrangement position of each magnetic ring and the selection of the magnetization direction of each magnetic ring, each pair of magnetic rings does not play only one role, but at least two roles, thereby ensuring the stability of the central rotation and suspension of the impeller 30.

[0039] like Figure 4As shown, the wheel shaft 31 of the impeller 30 is sleeved with an inner rotor sleeve 32, and the inner rotor sleeve 32 completely wraps the wheel shaft 31, the inner rotor magnetic ring A1 and the first axial magnetic ring C1 and forms a sealed fit. The pump housing 20 includes an upper housing 21 and an isolation sleeve 22, and the two are sealed and connected. The impeller 30 is arranged in a chamber surrounded by the upper housing 21 and the isolation sleeve 22. In the present invention, the inner rotor magnetic ring A1 and the first axial magnetic ring C1 can be bonded to the wheel shaft 31 by dispensing glue, and the wheel shaft 31, the inner rotor magnetic ring A1 and the first axial magnetic ring C1 are completely wrapped into a whole by the inner rotor sleeve 32. The outer part of the inner rotor sleeve 32 is relatively regular and smooth, so the shear force on the blood flowing through the outer part of the inner rotor sleeve 32 is smaller, and the hemolysis effect is better. The impeller 30 is suspended in the pump housing 20, so that the impeller 30 is completely out of contact with the pump housing 20 when rotating at high speed, reducing friction and reducing damage to the blood. The inner rotor sleeve 32 is selected from one of polytetrafluoroethylene and zirconium oxide ceramics, which has good biocompatibility and good wear resistance. The isolation sleeve 22 is selected from one of stainless steel and titanium alloy, wherein the thickness, strength and eddy current loss of titanium alloy are better than those of stainless steel, and should be used first. The inner cavity of the isolation sleeve 22 is a relatively smooth and fluent chamber, and the outer wall of the inner rotor sleeve 32 is also a relatively smooth and fluent continuous barrel shape, which makes the blood flow smoother, further reducing the formation of thrombus, and also reducing the damage to blood.

[0040] like Figure 6 As shown, the impeller 30 includes a plurality of long blades 33 and a plurality of short blades 34, and the long blades 33 and the short blades 34 are alternately arranged on the wheel disk 35 and spirally surround the wheel disk 35; the impeller 30 is a semi-open structure, and the composite blade design thereon reduces the diffusion degree of the impeller flow channel without increasing the inlet displacement of the impeller 30, inhibits the flow separation on the blade surface, and has a relatively obvious improvement in the hydraulic performance of the blood pump.

[0041] As a preferred embodiment of the present invention, the blade groups are provided in multiple groups and are evenly spaced on the impeller 35. The tail of the long blade 33 and the head of the long blade 33 and the short blade 34 in the adjacent blade group are basically located on the same radial line. The head end of the blade is arc-shaped and the tail has an inclined guide portion, which is beneficial to reduce blood damage and guide the blood to increase the head. The rotation angle between the head and tail of the short blade 34 is α, and the rotation angle between the head and tail of the long blade 33 is β, wherein α<β<2α. The rotation angle and position of the blade group have a very important influence on the hydraulic performance and hemolytic performance of the impeller 30. Figure 7 In the figure, the impeller structure shown by the solid line is Example 1 of the present invention, and the impeller structure shown by the dotted line is Example 2 of the present invention. The blade rotation angle and the position of the blade head are different in the two embodiments, and the other conditions are the same for both. The hydraulic performance and hemolytic performance are verified through simulation experiments below.

[0042] Considering the application scenario of the blood pump, this simulation uses a combination of mass flow inlet and pressure outlet, where the inlet mass flow is 0.083333 kg / s, the outlet pressure is 13332 Pa, and referring to the physical properties of blood, the transport medium density is 1050 kg / m 3 , the dynamic viscosity is The SST model was selected as the turbulence model, the impeller speed was 2000rpm, all physical interfaces in the pump adopted no-slip wall boundary conditions, the near-wall area adopted the standard wall function, the interface between the rotating domain and the stationary domain was set to "Frozen rotor", and the interface between the stationary domain was set to "None", the maximum number of steady-state iterations was 2000, the second-order discrete format was used, and the convergence accuracy was set to 10 -6 .

[0043] in Fig. 9 This is a comparison diagram of the flow field velocity vector distribution simulation in Example 1 and Example 2. In Example 2, the pressure change gradient is slower, which is conducive to the improvement of hemolytic performance; Fig.10 This is a comparison diagram of the shear stress simulation on the impeller wall in Example 1 and Example 2. It can be seen that there are fewer dark areas in Example 2, that is, the shear stress level on the impeller wall in Example 2 is significantly lower than that in Example 1; Fig.11 This is a comparison of the head-flow curves in Example 1 and Example 2. Under the condition of the same flow rate, the head of the impeller in Example 2 is higher; Fig.12 It is a comparison diagram of the pressure distribution simulation in Example 1 and Example 2. It can be seen that the pressure at the impeller inlet in Example 2 is smaller, and the impeller inlet and outlet pressure difference in Example 2 is greater than the impeller inlet and outlet pressure difference in Example 1.

[0044] It can be seen from the above simulation effect comparison diagram that the inlet and outlet pressure difference in Example 2 is larger, the wall shear force is smaller, the head is larger, and the hydraulic performance and hemolytic performance are significantly better than those in Example 1, so it is a more preferred embodiment of the present invention.

[0045] See also Figure 1 and Figure 5 A concave cavity is provided in the mounting seat 10, and the pump casing 20 is placed in the concave cavity to form a fixed connection, and a closed structure is formed between the pump casing 20 and the mounting seat 10. The pump casing 20 and the mounting seat 10 form a detachable connection and can form a closed structure at the same time. The upper shell 21 is provided with an inlet pipe 211 and a liquid outlet pipe 212, wherein the inlet pipe 211 is axially consistent with the impeller 30, and the liquid outlet pipe 212 is arranged on the side of the upper shell 21, and the middle part of the wheel disc 35 protrudes toward the inner cavity of the inlet pipe 211 and is provided with a guide cone column 36, which has a certain inhibitory effect on the production of vortexes at the inlet and other adverse flow conditions, and better improves the inlet flow condition of the blood pump and improves the cavitation performance of the blood pump.

[0046] The flow channel in the upper shell 21 is an annular flow channel (such as Figure 8b as shown) or spiral flow channel (as shown Figure 8a As shown in the figure, the spiral water pressure chamber has relatively good hydraulic performance, but the small gap at the tongue causes the dynamic and static interference to increase the stress of the blood medium, resulting in blood squeezing and shearing damage, resulting in relatively poor hemolysis performance. The gap between the impeller and the pump casing of the annular water pressure chamber is large, the squeezing and shearing damage of the blood is small, the hemolysis performance is better, but the hydraulic performance is relatively weak. The design method of the flow channel can be reasonably selected according to the actual blood pump flow requirements.

[0047] During production, the entire impeller 30 can be assembled and placed in the closed pump housing 20 as a whole to effectively prevent liquid leakage. When in use, the whole is made into a disposable component. For different patients, the mounting seat and the drive unit 40 thereon can be reused, which can greatly improve the utilization rate of the pump, save costs, and benefit more patients. At the same time, the pump housing 20 and the mounting seat 10 are completely independent, so a heat sink (such as Figure 5 The heat dissipation ribs on the left and right sides shown in the figure), the flushing system (not shown in the figure) and other structures assist in heat dissipation, thereby improving the safety performance of the entire blood pump operation.

[0048] It should be noted that the above describes some embodiments of the present application. Other embodiments are within the scope of the appended claims. In some cases, the schemes or steps recorded in the claims can be performed in an order different from that in the above embodiments and still achieve the desired results. In addition, the processes depicted in the accompanying drawings do not necessarily require the specific order or continuous order shown to achieve the desired results. In some embodiments, multitasking and parallel processing are also possible or may be advantageous.

Claims

1. A magnetically suspended blood pump, comprising a mounting seat (10), a pump housing (20), and an impeller (30) located in the pump housing (20), characterized in that: The inner rotor magnetic ring (A1) on the peripheral wall of the impeller (30) and the outer rotor magnetic ring (A2) in the mounting seat (10) are magnetically coupled to form an axial support system; the drive unit (40) drives the outer rotor magnetic ring (A2) to rotate, thereby driving the inner rotor magnetic ring (A1) to rotate; the dynamic magnetic ring (B1) on the peripheral wall of the impeller (30) and the static magnetic ring (B2) on the inner wall of the pump casing (20) form a group of radial passive magnetic bearings that repel each other; the first axial magnetic ring (C1) at the bottom of the impeller (30) and the second axial magnetic ring (C2) in the mounting seat (10) form a group of radial passive magnetic bearings that attract each other; A drive unit (40) is arranged in the mounting seat (10), the drive unit (40) comprising a rotating shaft (41), a magnetic steel (42) being fixed on the shaft body of the rotating shaft (41), a stator coil (43) being arranged on the outer periphery of the magnetic steel (42), a bearing (44) being arranged at each end of the rotating shaft (41), and the second axial magnetic ring (C2) being fixed at a position of the rotating shaft (41) near the bottom of the impeller (30) and leaving a gap with the bottom of the pump casing (20).

2. The magnetically suspended blood pump according to claim 1, characterized in that: A rotating body (45) is extended from the end of the rotating shaft (41) and the two are arranged coaxially. The rotating body (45) is in the shape of a barrel with its opening facing the impeller (30). The outer rotor magnetic ring (A2) is fixed on the inner wall of the barrel. The lower part of the pump housing (20) is placed in the barrel. An inner rotor magnetic ring (A1) is fixed on the outer peripheral wall of the axle (31) of the impeller (30) at a position corresponding to the outer rotor magnetic ring (A2).

3. The magnetically suspended blood pump according to claim 1, characterized in that: The second axial magnetic ring (C2) is embedded in the rotating shaft (41), the end surface of the second axial magnetic ring (C2) is flush with the barrel bottom of the rotating body (45), and is coaxially arranged with the rotating shaft (41) and the second axial magnetic ring (C2); the first axial magnetic ring (C1) is embedded in the bottom of the impeller (30), the end surface of the first axial magnetic ring (C1) is flush with the bottom of the impeller (30), and the first axial magnetic ring (C1) and the impeller (30) are coaxially arranged.

4. The magnetically suspended blood pump according to claim 1, characterized in that: The dynamic magnetic ring (B1) is arranged on the peripheral wall of the wheel shaft (31) of the impeller (30) located outside the rotating body (45), and the static magnetic ring (B2) is arranged on the inner wall of the pump casing (20) corresponding to the position of the dynamic magnetic ring (B1).

5. The magnetically suspended blood pump according to claim 1, characterized in that: The first axial magnetic ring (C1) and the second axial magnetic ring (C2) are axially magnetized magnetic ring structures, with different magnetic poles arranged adjacent to each other; The inner rotor magnetic ring (A1) and the outer rotor magnetic ring (A2) are radially magnetized multi-stage permanent magnetic tiles or soft magnet structures, and different magnetic poles are arranged adjacent to each other to achieve synchronous rotation and axial limitation of the two; the dynamic magnetic ring (B1) and the static magnetic ring (B2) are axially magnetized permanent magnets, and the same magnetic poles are arranged adjacent to each other.

6. The magnetically suspended blood pump according to claim 1, characterized in that: An inner rotor sleeve (32) is sleeved on the wheel shaft (31) of the impeller (30), and the inner rotor sleeve (32) completely encloses the wheel shaft (31), the inner rotor magnetic ring (A1) and the first axial magnetic ring (C1) to form a sealed fit. The pump housing (20) comprises an upper housing (21) and an isolation sleeve (22), and the two are sealedly connected. The impeller (30) is arranged in a chamber enclosed by the upper housing (21) and the isolation sleeve (22).

7. The magnetically suspended blood pump according to claim 1, characterized in that: The impeller (30) comprises a plurality of long blades (33) and a plurality of short blades (34); the long blades (33) and the short blades (34) are alternately arranged on the wheel disc (35) and spirally arranged around the wheel disc (35); one long blade (33) and one short blade (34) form a blade group.

8. The magnetically suspended blood pump according to claim 7, characterized in that: The blade groups are provided in a plurality of groups and are evenly spaced on the wheel disc (35); the head end of the blade is arc-shaped and the tail end has an inclined guide portion; the rotation angle between the head and tail of the short blade (34) is α, and the rotation angle between the head and tail of the long blade (33) is β, wherein α<β<2α.

9. The magnetically suspended blood pump according to claim 1, characterized in that: A concave cavity is provided in the mounting seat (10), the pump housing (20) is placed in the concave cavity to form a fixed connection, a closed structure is formed between the pump housing (20) and the mounting seat (10), the upper housing (21) is provided with a liquid inlet pipe (211) and a liquid outlet pipe (212), wherein the liquid inlet pipe (211) is axially consistent with the impeller (30), the liquid outlet pipe (212) is provided on the side of the upper housing (21), a guide cone column (36) is provided in the middle of the wheel disc (35) protruding toward the inner cavity of the liquid inlet pipe (211), and the flow channel in the upper housing (21) is an annular flow channel or a spiral flow channel.

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