Five-degree-of-freedom permanent magnet biased magnetic suspension blood pump

Abstract

The invention discloses a five-degree-of-freedom permanent magnet biased magnetic suspension blood pump which comprises a pump shell, a rotor impeller, a magnetic suspension bearing and a motor used for driving the rotor impeller to rotate and do work, the magnetic suspension bearing comprises a bearing stator and a bearing rotor, and the bearing stator is fixed in an inlet pipe; the stator comprises an annular stator core and stator magnetic rings distributed at the two axial ends of the stator core, a plurality of first stator teeth are arranged on the inner wall of the stator core in the radial direction, and each first stator tooth is wound with a first coil; the bearing rotor is fixed in the pump rotor, the bearing rotor comprises a rotor iron core, rotor teeth are arranged on the outer circumferential surface of the rotor iron core, and the multiple first stator teeth are arranged opposite to the rotor teeth in the radial direction; the stator magnetic rings located at the two axial ends of the stator iron core are magnetized in the axial direction, the magnetizing directions are opposite, and closed magnetic loops can be formed between the stator magnetic rings and the stator iron core and between the stator magnetic rings and the rotor iron core. Five-degree-of-freedom suspension control can be achieved, the size is small, and power consumption is low.

Description

Technical Field

[0001] The invention relates to the technical field of medical devices, and in particular to a five-degree-of-freedom permanent magnet biased magnetic suspension blood pump. Background Art

[0002] Blood pumps, or ventricular assist devices, are used to provide mechanical support for blood circulation in patients with progressive refractory heart failure, i.e. transitional treatment before heart transplantation or to restore heart function, as well as long-term treatment. The current mainstream third-generation magnetic levitation blood pumps mainly use hydraulic suspension, magnetic fluid suspension, hydrodynamic bearing contact, and full magnetic suspension. Among them, full magnetic suspension technology is the most stable of the current blood pump suspension methods. The main advantages of magnetic levitation technology are: no friction, less heat generation, good blood compatibility, high durability, reduced noise and vibration, and improved patient comfort.

[0003] However, in order to achieve the full magnetic levitation function, the current full magnetic levitation blood pumps on the market use high-power electromagnetic drives and complex magnetic circuit structures, which makes it difficult to effectively reduce the overall volume and the power consumption remains high. For blood pumps that need to be implanted in the body, the larger volume not only increases the difficulty and risk of surgery, but also causes greater trauma and burden on the patient's body. The blood pump has poor adaptability in the body. At the same time, high power consumption will also increase the patient's dependence on external energy, affecting the patient's normal activities and life. Therefore, how to achieve low power, small size and light weight for blood pumps is still a major problem at present. Summary of the invention

[0004] The problem to be solved by the present invention is to provide a five-degree-of-freedom permanent magnet biased magnetic suspension blood pump to overcome the defects of the existing full magnetic suspension blood pump, such as large size and high power consumption.

[0005] The technical solution adopted by the present invention to solve its technical problems is: a five-degree-of-freedom permanent magnet biased magnetic suspension blood pump, comprising a pump housing, a rotor impeller, a magnetic suspension bearing and a motor for driving the rotor impeller to rotate and do work, the pump housing comprising a pump chamber and an inlet pipe fixedly arranged at the top of the pump chamber and connected to the pump chamber, the rotor impeller comprising an impeller and a pump rotor fixedly arranged at the top of the impeller, the impeller being accommodated in the pump chamber, and the pump rotor extending into the inlet pipe;

[0006] The magnetic bearing comprises a bearing stator and a bearing rotor. The bearing stator is fixed in the inlet pipe and comprises an annular stator core and stator magnetic rings distributed at the two axial ends of the stator core. A plurality of first stator teeth distributed in annular shapes and at equal intervals are radially arranged on the inner wall of the stator core, and a first coil is wound around each of the first stator teeth. The bearing rotor is fixed in the pump rotor and is gap-matched with the bearing stator. The bearing rotor comprises a rotor core, and rotor teeth are arranged on the outer circumferential surface of the rotor core. A plurality of the first stator teeth are radially arranged opposite to the rotor teeth. The stator magnetic rings located at the two axial ends of the stator core are magnetized along the axial direction and in opposite directions, and a closed magnetic circuit can be formed between the stator magnetic ring and the stator core and the rotor core.

[0007] As a further improvement of the present invention, the bearing stator also includes two first stator yokes, which are respectively fixed on the ends of the stator magnetic ring located at the axial ends of the stator core and facing away from each other, and the two first stator yokes both have an annular inner flange extending radially inward, and the two ends of the rotor core have an annular first outer flange extending radially outward, and the two inner flanges correspond one-to-one to the two first outer flanges, are distributed radially relative to each other and are clearance-matched.

[0008] As a further improvement of the present invention, the bearing rotor further comprises rotor magnetic rings distributed at both axial ends of the rotor core, and the stator magnetic ring and the rotor magnetic ring located on the same side of the axial direction are distributed radially opposite to each other;

[0009] The rotor magnetic rings at the axial ends of the rotor core are magnetized axially and in opposite directions. Meanwhile, the magnetization direction of any rotor magnetic ring is opposite to that of the stator magnetic ring radially opposite to it.

[0010] As a further improvement of the present invention, the bearing rotor further comprises two rotor yokes, the two rotor yokes are respectively fixed on ends of the rotor magnetic ring located at two axial ends of the rotor core and facing away from each other, and both of the two rotor yokes have an annular second outer flange extending radially outward;

[0011] The bearing stator also includes two first stator yokes, which are respectively fixed on the ends of the stator magnetic ring located at the axial ends of the stator core and facing away from each other, and the two first stator yokes both have an annular inner flange extending radially inward, and the two inner flanges correspond one-to-one to the two second outer flanges, which are relatively distributed radially and fit with clearance.

[0012] As a further improvement of the present invention, the rotor teeth are provided in plurality and are spaced apart and distributed along the axial direction, and the inner side surface of each of the first stator teeth is provided with a plurality of tooth portions, which are the same in number as the rotor teeth and are distributed one by one.

[0013] As a further improvement of the present invention, the magnetic suspension bearing is configured with at least two magnetic suspension bearings arranged and distributed along the axial direction, and non-magnetic washers are installed between two adjacent bearing stators and two adjacent bearing rotors.

[0014] As a further improvement of the present invention, the five-degree-of-freedom permanent magnet biased magnetic levitation blood pump also includes two groups of rotor position detection components, and the two groups of rotor position detection components include sensor components and detection magnetic rings. One sensor component is respectively installed at the upper and lower ends of the inlet pipe, and one detection magnetic ring is respectively installed at the upper and lower ends of the pump rotor. The two sensor components and the two detection magnetic rings are used in a one-to-one correspondence to detect the position of the pump rotor.

[0015] As a further improvement of the present invention, the sensor assembly includes a mounting ring, a plurality of Hall sensors and a plurality of buckle groups, the number of the Hall sensors and the buckle groups are the same as the number of the first coils and correspond one to one; the mounting ring is provided with a plurality of mounting grooves at equal intervals in an annular manner, and a mounting plate is formed in each of the mounting grooves, and the plurality of Hall sensors are respectively mounted on the plurality of mounting plates in a one-to-one correspondence through the plurality of buckle groups;

[0016] The buckle group includes a first buckle and two second buckles, both of which are U-shaped. The first buckle is fixed to the mounting plate by a positioning pin, and its opening direction is distributed radially inward, and the two claws on the first buckle are respectively clamped on the upper and lower sides of the Hall sensor; the two second buckles are respectively arranged on the left and right sides of the Hall sensor, and are clamped on the mounting plate, and the opening directions of the two second buckles are distributed radially outward;

[0017] Magnetic shielding washers are provided on both the upper and lower sides of the mounting ring, and the magnetic shielding washers are used together with the buckle assembly to magnetically shield the remaining surfaces of the Hall sensor except for a side surface facing the detection magnetic ring.

[0018] As a further improvement of the present invention, the motor includes a motor stator installed on the top of the pump chamber and a motor magnetic ring installed on the impeller, the motor stator includes a second stator yoke and a plurality of second stator teeth axially arranged on the bottom surface of the second stator yoke and distributed in a ring-shaped and equidistant pattern, each of the second stator teeth is wound with a second coil; a plurality of tooth slots are arranged in a ring-shaped and equidistant pattern at the top of the pump chamber, the end of the second stator tooth protrudes out of the second coil and is inserted into the corresponding tooth slot, and is axially arranged opposite to the motor magnetic ring.

[0019] As a further improvement of the present invention, a lower chamber magnetic ring is installed at the bottom of the pump chamber, and an impeller magnetic ring is installed at the bottom of the impeller. The lower chamber magnetic ring and the impeller magnetic ring are axially arranged opposite to each other and there is suction between the two.

[0020] The beneficial effects of the present invention are:

[0021] 1. The present invention provides a five-degree-of-freedom permanent magnet biased magnetic suspension blood pump. By installing the magnetic suspension bearing in the inlet pipe and the pump rotor of the blood pump, the volume of the blood pump can be greatly reduced, and the thinning of the pump cavity can improve the patient's comfort and physiological adaptability. At the same time, since the magnetic suspension bearing is installed in the inlet pipe and the pump rotor of the blood pump, the heat generated by the magnetic suspension bearing during operation can be transferred to the inner tube. When the blood pump is running, the heat can be taken away by the rapid flow of blood, so the heat dissipation performance is good and the service life is improved.

[0022] 2. The magnetic bearing of the present invention is provided with stator magnetic rings at both ends of the stator core, and the permanent magnetic force of the stator magnetic rings is used to provide a static bias magnetic field. At the same time, the electromagnet composed of the first stator tooth and the first coil is used as a dynamic suspension auxiliary adjustment. This combination of permanent magnet and electromagnetic not only maintains the low power consumption characteristics of the permanent magnetic bearing, but also realizes high-precision suspension and adjustment through electromagnetic control, and realizes five-degree-of-freedom suspension. It can not only reduce the bias current required for electromagnetic control and significantly reduce the power consumption of the system, making the magnetic bearing more advantageous in application scenarios that require long-term operation or limited energy supply, but also makes the magnetic bearing have higher load-bearing capacity and better stability, and can adapt to various complex working conditions;

[0023] 3. The stator magnetic rings on the upper and lower sides of the stator core in the present invention can form two closed magnetic loops through the first stator teeth of the stator core in the middle and the rotor teeth of the rotor core, so that the magnetic force utilization rate is higher. Under the same magnetic force requirements, the volume of the magnetic suspension bearing can be smaller and the structure is more compact. It can provide a stable static bias magnetic field. At the same time, the bias current required for electromagnetic control is small, thereby achieving the purpose of low power consumption, small volume and light weight. Under the premise of ensuring blood compatibility and long-term reliability, more efficient energy utilization and more compact structural design can be achieved to improve the overall performance and clinical applicability of the blood pump;

[0024] 4. The present invention installs the Hall sensor on the mounting ring through the first clip and the two second clips, and realizes reliable position limiting of the Hall sensor to prevent its position from deviation; at the same time, the magnetic shielding gasket is used together with the clip group to magnetically shield the remaining surfaces of the Hall sensor except for the side facing the detection magnetic ring, which can protect the Hall sensor only from detecting the magnetic field directly opposite to it, reduce the influence of other magnetic fields on the Hall sensor, and realize accurate detection. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a three-dimensional diagram of the five-degree-of-freedom permanent magnet biased magnetic suspension blood pump of the present invention;

[0026] Figure 2 It is a cross-sectional view of the five-degree-of-freedom permanent magnet biased magnetic suspension blood pump of the present invention;

[0027] Figure 3 An exploded view of the five-degree-of-freedom permanent magnet biased magnetic suspension blood pump of the present invention;

[0028] Figure 4 This is an exploded view of the present invention after removing the rotor impeller and the lower chamber of the pump;

[0029] Figure 5 is a cross-sectional view of a rotor impeller in the present invention;

[0030] Figure 6 A three-dimensional diagram of the magnetic bearing of the present invention;

[0031] Figure 7 is a cross-sectional view of the magnetic bearing in the present invention;

[0032] Figure 8 An exploded view of the bearing stator in the present invention;

[0033] Fig. 9 is a three-dimensional diagram of the bearing rotor in the present invention;

[0034] Fig.10 It is a cross-sectional view of two sets of magnetic bearings in the present invention;

[0035] Fig.11 It is a schematic diagram of the magnetic circuit of the magnetic suspension bearing in the present invention;

[0036] Fig.12 It is a schematic diagram of the axial offset of the bearing rotor of the magnetic bearing in the present invention;

[0037] Fig.13 It is a schematic diagram of radial offset of the bearing rotor of the magnetic bearing in the present invention;

[0038] Fig.14 It is a schematic diagram of radial deflection of bearing rotors of two sets of magnetic bearings in the present invention;

[0039] Fig.15 It is a perspective view of another embodiment of the assembly of the stator core and the first coil in the present invention.

[0040] Fig.16 A perspective view of a sensor assembly in the present invention;

[0041] Fig.17 An exploded view of the sensor assembly of the present invention;

[0042] Fig.18 is a three-dimensional diagram of the motor stator in the present invention;

[0043] Fig.19 An exploded view of the lower pump chamber of the pump housing of the present invention;

[0044] Fig. 20 is a perspective view of another embodiment of the bearing rotor in the present invention;

[0045] Fig.21 is a cross-sectional view of another embodiment of the magnetic bearing of the present invention;

[0046] Fig. 22 It is a cross-sectional view of another embodiment of the magnetic bearing in the present invention.

[0047] Combined with the accompanying drawings, the following description is given:

[0048] 1. Pump casing; 11. Pump chamber; 111. Tooth groove; 12. Inlet pipe; 121. Outer pipe; 122. Inner pipe; 123. Magnetic shielding pipe; 13. Outlet pipe; 2. Rotor impeller; 21. Impeller; 22. Pump rotor; 3. Magnetic suspension bearing; 31. Bearing stator; 311. Stator core; 3111. First stator tooth; 31111. Tooth; 312. Stator magnetic ring; 313. First coil; 314. First stator yoke; 3141. Inner flange; 32. Bearing rotor; 321. Rotor core; 3211. Rotor tooth; 3212. First outer convex flange; 322, rotor magnetic ring; 323, rotor yoke; 3231, second outer flange; 4, motor; 41, motor stator; 411, second stator yoke; 412, second stator tooth; 413, second coil; 42, motor magnetic ring; 5, non-magnetic gasket; 6, rotor position detection assembly; 61, sensor assembly; 611, mounting ring; 6111, mounting plate; 612, Hall sensor; 613, first buckle; 614, second buckle; 615, positioning pin; 62, detection magnetic ring; 63, magnetic shielding gasket; 7, lower chamber magnetic ring; 8, impeller magnetic ring. DETAILED DESCRIPTION

[0049] A preferred embodiment of the present invention is described in detail below in conjunction with the accompanying drawings.

[0050] Embodiment 1

[0051] See also Figures 1 to 19 The present invention provides a five-degree-of-freedom permanent magnet biased magnetic suspension blood pump, comprising: a pump housing 1, a rotor impeller 2, a magnetic suspension bearing 3 and a motor 4.

[0052] The rotor impeller 2 is accommodated in the pump housing 1, and the motor 4 is installed on the pump housing 1 and the rotor impeller 2. The motor 4 is used to drive the rotor impeller 2 to rotate and do work, and drive the blood circulation under the centrifugal force of the rotor impeller 2. The magnetic bearing 3 is also installed on the pump housing 1 and the rotor impeller 2, and is used to constrain the five degrees of freedom of the rotor impeller 2 except for the rotation, so as to control the suspension of the rotor impeller 2.

[0053] See also Figures 2 to 4 The pump housing 1 includes a pump chamber 11, an inlet pipe 12 and an outlet pipe 13.

[0054] In this embodiment, the pump chamber 11 is composed of an upper pump chamber and a lower pump chamber, and an outlet pipe is provided on one side of the pump chamber 11. The inlet pipe 12 is fixedly arranged at the top of the pump chamber 11 and communicated with the pump chamber 11. When the blood pump is working, blood enters the pump chamber 11 through the inlet pipe 12 and then flows out through the outlet pipe.

[0055] In this embodiment, the inlet pipe 12 includes an outer pipe 121 and an inner pipe 122, the inner pipe 122 is integrally connected to the top of the upper pump cavity, the outer pipe 121 is sleeved on the outside of the inner pipe 122, and the gap between the outer pipe 121 and the inner pipe 122 is used to install the bearing stator 31 of the magnetic suspension bearing 3. The outlet pipe 13 is fixed to the top of the upper pump cavity and is also sleeved on the outside of the inner pipe 122, and the bottom of the outer pipe 121 is fixedly connected to the top of the outlet pipe 13. The gap between the outlet pipe 13 and the inner pipe 122 is used to install the motor stator 41 of the motor 4, and the pipe opening on the outlet pipe 13 is used to lead the cables of the magnetic suspension bearing 3 and the motor 4 outward.

[0056] Furthermore, the rotor impeller 2 includes an impeller 21 and a pump rotor 22 coaxially fixed to the top of the impeller 21 . The impeller 21 is accommodated in the pump cavity 11 , and the pump rotor 22 extends into the inner tube 122 of the inlet pipe 12 .

[0057] See also Figures 6 to 9, the magnetic bearing 3 includes a bearing stator 31 and a bearing rotor 32. The bearing stator 31 is fixed in the inlet pipe 12, between the outer tube 121 and the inner tube 122. The bearing stator 31 includes an annular stator core 311 and stator magnetic rings 312 distributed at both axial ends of the stator core 311. In this embodiment, the number of stator magnetic rings 312 installed at the upper and lower ends of the stator core 311 is one. Of course, in other embodiments of the present invention, a plurality of superimposed stator magnetic rings 312 can also be fixedly installed at the upper and lower ends of the stator core 311. For ease of understanding, this article takes the installation of a stator magnetic ring 312 at each of the upper and lower ends of the stator core 311 as an example for explanation.

[0058] Preferably, the outer diameter and the ring width of the two stator magnetic rings 312 are the same as the outer diameter and the ring width of the ring portion of the stator core 311 , so as to ensure the consistency of the outer diameter of the bearing stator 31 .

[0059] Furthermore, a plurality of first stator teeth 3111 distributed in an annular shape and at equal intervals are radially arranged on the inner wall of the stator core 311 , and a first coil 313 is wound around each first stator tooth 3111 .

[0060] See also Figure 5 The pump rotor 22 is tubular, and is provided with a rotor inner tube and a rotor outer tube sleeved on the outer side of the rotor inner tube. The internal channel of the rotor inner tube and the channel between the rotor outer tube and the inlet tube 12 are both used as blood circulation channels. This dual-channel design can increase the blood flow efficiency. The bearing rotor 32 is annular, and is fixed in the gap between the rotor inner tube and the rotor outer tube of the pump rotor 22. The bearing rotor 32 and the bearing stator 31 are radially oppositely arranged and have clearance fit. The bearing rotor 32 includes a rotor core 321, and rotor teeth 3211 are provided on the outer circumferential surface of the rotor core 321, and a plurality of first stator teeth 3111 are radially oppositely arranged to the rotor teeth 3211.

[0061] In the present invention, the two stator magnetic rings 312 located at the axial ends of the stator core 311 are magnetized along the axial direction and in opposite directions, so that a closed magnetic circuit can be formed between the stator magnetic ring 312 and the stator core 311 and the rotor core 321 .

[0062] The radial suspension of the rotor impeller 2 of the present invention is mainly controlled by the permanent magnetic force between the bearing stator 31 and the bearing rotor 32. The permanent magnetic force generated by the two stator magnetic rings 312 at the upper and lower ends of the stator core 311 converges into the stator core 311 to form a main magnetic path. The main magnetic path is transmitted from the first stator tooth 3111 on the stator core 311 through the air gap between the stator core 311 and the rotor core 321 through the rotor tooth 3211 to the rotor core 321, and finally returns to the stator magnetic ring 312, so that a closed magnetic circuit can be formed between the stator magnetic rings 312 on the upper and lower sides and the stator core 311 and the rotor core 321, and the rotor impeller 2 is driven to suspend radially by the permanent magnetic force generated by the stator magnetic ring 312 on the rotor core 321. At the same time, by controlling the current direction and magnitude of the corresponding first coil 313, the attraction of the corresponding first stator tooth 3111 to the rotor core 321 is controlled, which serves as an auxiliary control force to regulate the radial displacement or deflection caused by interference to the rotor impeller 2, so as to return it to the radially centered suspension position.

[0063] The axial suspension of the rotor impeller 2 of the present invention is controlled by the permanent magnetic force between the bearing stator 31 and the bearing rotor 32, that is, it is controlled by the mutual attraction between the first stator tooth 3111 of the stator core 311 and the rotor tooth 3211 of the rotor core 321. When the rotor impeller 2 generates axial displacement, in order to ensure that the polar facing area of ​​the first stator tooth 3111 and the rotor tooth 3211 remains unchanged during the magnetic circuit transmission process, the bearing stator 31 exerts a permanent magnetic force on the bearing rotor 32 in the axial direction to restore the origin, so that the rotor impeller 2 returns to the axial suspension position. In this structure, whether the rotor impeller 2 is axially upward or axially downward, the axial direction will generate a force to restore the origin.

[0064] It can be seen that the magnetic bearing 3 in the present invention adopts the form of a combination of permanent magnet and electromagnet, and uses the permanent magnetic force of the stator magnetic ring 312 to provide a static bias magnetic field, and uses the electromagnet composed of the first stator tooth 3111 and the first coil 313 as a dynamic suspension auxiliary adjustment, which not only maintains the low power consumption characteristics of the permanent magnetic bearing, but also realizes high-precision suspension and adjustment through electromagnetic control, and realizes five-degree-of-freedom suspension. It can not only reduce the bias current required for electromagnetic control and significantly reduce the power consumption of the system, making the magnetic bearing 3 more advantageous in application scenarios that require long-term operation or limited energy supply, but also makes the magnetic bearing 3 have higher load-bearing capacity and better stability, and can adapt to various complex working conditions.

[0065] There is always a contradiction between the power consumption and volume of the magnetic suspension bearing 3 on the market, that is, when the power is low, the volume must be large; and when the volume is small, higher power is required to maintain stable suspension, and the heat generation will increase. In order to solve this technical problem, the present invention is provided with stator magnetic rings 312 at both ends of the stator core 311, and the stator magnetic rings 312 on both sides can form two closed magnetic circuits through the first stator teeth 3111 of the stator core 311 in the middle and the rotor teeth 3211 of the rotor core 321, so that the magnetic force utilization rate is higher, and under the same magnetic force requirements, the volume can be smaller and the structure is more compact, and a stable static bias magnetic field can be provided. At the same time, the bias current required for electromagnetic control is small, thereby realizing low power consumption, small volume and light weight five-degree-of-freedom permanent magnet bias magnetic suspension, and on the premise of ensuring blood compatibility and long-term reliability, more efficient energy utilization and more compact structural design can be achieved to improve the overall performance and clinical applicability of the blood pump.

[0066] Domestic full magnetic levitation competing products are currently placed at the bottom of the pump cavity 11, requiring a thicker pump cavity. The present invention, on the other hand, adopts the method of installing the magnetic bearing 3 in the inlet pipe 12 and the pump rotor 22 of the blood pump, which can greatly reduce the volume of the blood pump, and the thinning of the pump cavity 11 can improve the patient's comfort and physiological adaptability. At the same time, since the magnetic bearing 3 is installed in the inlet pipe 12 and the pump rotor 22 of the blood pump, the heat generated by the magnetic bearing 3 during operation can be transferred to the inner tube 122. When the blood pump is running, the heat can be taken away by the rapid flow of blood, which has good heat dissipation performance and improves the service life.

[0067] See also Figure 6 and Figure 7 The bearing stator 31 also includes two first stator yokes 314, both of which are annular and are respectively fixed on the ends of the stator magnetic rings 312 located at the axial ends of the stator core 311 that are opposite to each other, and the ends of the two first stator yokes 314 are radially inwardly extended with annular inner flanges 3141, and the two ends of the rotor core 321 are radially outwardly extended with annular first outer flanges 3212, the two inner flanges 3141 correspond one by one to the two first outer flanges 3212, and are radially relatively distributed and clearance-matched, so as to reduce the magnetic field air gap between the first stator yoke 314 and the rotor core 321, and improve the magnetic force conduction efficiency.

[0068] like Fig.11As shown, the permanent magnetic forces generated by the two stator magnetic rings 312 at the upper and lower ends of the stator core 311 converge into the stator core 311 to form a main magnetic path. The main magnetic path is transmitted from the first stator tooth 3111 on the stator core 311 through the air gap between the stator core 311 and the rotor core 321 to the rotor core 321 through the rotor tooth 3211, and then transmitted toward the first outer flanges 3212 at the upper and lower ends of the rotor core 321, and finally returned to the corresponding two stator magnetic rings 312 through the upper and lower first stator yokes 314, so that a closed magnetic circuit can be formed among the stator magnetic rings 312, the stator core 311, the rotor core 321 and the first stator yoke 314 located on the same side of the axial direction. The present invention can strengthen the magnetic circuit structure, improve the magnetic force conduction efficiency, reduce magnetic force loss, enhance the static bias magnetic field provided by the stator magnetic ring 312, improve the suspension stability effect, and better reduce the power effect by arranging the first stator yoke 314 at the upper and lower ends of the stator core 311.

[0069] See also Figure 7 and Figure 8 , a plurality of rotor teeth 3211 are arranged and distributed along the axial direction at intervals. In this embodiment, the rotor teeth 3211 are specifically arranged as three. The inner side surface of each first stator tooth 3111 is provided with a plurality of tooth portions 31111 which are the same in number as the rotor teeth 3211 and are distributed one by one. While ensuring that the area of ​​the stator core 311 and the rotor core 321 facing each other remains unchanged, by increasing the number of rotor teeth 3211 and tooth portions 31111, it is beneficial to increase the size of the axial force, and at the same time, it can also form a plurality of branch magnetic paths, thereby further strengthening the magnetic path structure.

[0070] In the present invention, the number of the first stator teeth 3111 is configured to be more than three, and the number of the corresponding first coils 313 is also configured to be more than three, preferably four to eight. In this embodiment, four first stator teeth 3111 are specifically used, and the first coils 313 wound on the four first stator teeth 3111 work independently, so that when the rotor impeller 2 is radially offset or deflected, the current direction and magnitude of the corresponding first coils 313 can be independently controlled. Fig.15 As shown, in other embodiments of the present invention, the number of the first stator teeth 3111 is set to eight, and each of the eight first stator teeth 3111 is wound with an independently controllable first coil 313. By independently controlling the eight first coils 313, a more stable auxiliary control radial suspension effect can be provided.

[0071] It is worth mentioning that the magnetic bearing 3 in the present invention is configured with at least two axially arranged and distributed magnetic bearings, such as Fig.10As shown, this article specifically takes two magnetic suspension bearings 3 as an example for explanation. The present invention provides two sets of magnetic suspension bearings 3, and relies on the permanent magnetic force of the stator magnetic rings 312 of the two sets of magnetic suspension bearings 3 to jointly provide a static bias magnetic field, thereby further improving the suspension stability of the rotor impeller 2 in the axial and radial directions, and having a better constraint effect on the axial and radial degrees of freedom, especially the radial deflection degree of freedom.

[0072] Among them, non-magnetic washers 5 are installed between the two bearing stators 31 and the two bearing rotors 32, which can effectively prevent the two sets of magnetic suspension bearings 3 from interfering with each other.

[0073] See also Figure 2 , Figure 4 and Figure 5 The five-DOF permanent magnet biased magnetic suspension blood pump of the present invention also includes two groups of rotor position detection components 6, both of which include sensor components 61 and detection magnetic rings 62. A sensor component 61 is installed at each of the upper and lower ends of the inlet pipe 12, and the two sensor components 61 are located at the top and bottom of the two bearing stators 31 respectively; a detection magnetic ring 62 is installed at each of the upper and lower ends of the pump rotor 22, and the two detection magnetic rings 62 are located at the top and bottom of the two bearing rotors 32 respectively, and the two detection magnetic rings 62 are distributed one by one with the two sensor components 61 in a radial direction. The two sensor components 61 and the two detection magnetic rings 62 are used in a one-to-one correspondence to detect the position of the pump rotor 22.

[0074] The present invention sets two upper and lower groups of rotor position detection components 6 to jointly detect the position of the rotor impeller 2, so as to obtain whether the rotor impeller 2 has radial displacement or radial deflection, so as to accurately control the current direction and size of the corresponding first coil 313, and drive the rotor impeller 2 to return to the radially centered suspension position.

[0075] In this embodiment, the detection magnetic ring 62 can be magnetized in the radial direction so that its magnetic polarity is distributed on the inner and outer circles.

[0076] See also Fig.16 and Fig.17 The sensor assembly 61 includes a mounting ring 611, a plurality of Hall sensors 612 and a plurality of buckle groups. The number of the Hall sensors 612 and the buckle groups is the same as that of the first coil 313 and corresponds one to one. The mounting ring 611 is provided with a plurality of mounting grooves at equal intervals in an annular manner, and a mounting plate 6111 is formed in each mounting groove. The plurality of Hall sensors 612 are respectively mounted on the plurality of mounting plates 6111 through a plurality of buckle groups in a one-to-one correspondence. In this embodiment, the number of the Hall sensors 612, the buckle groups and the mounting grooves is four.

[0077] Further, the buckle group includes a first buckle 613 and two second buckles 614, both of which are U-shaped. A fixing hole is radially opened on the mounting plate 6111. The first buckle 613 is fixed to the mounting plate 6111 by a positioning pin 615, and its opening direction is radially inwardly distributed. At the same time, the two claws on the first buckle 613 are respectively clamped on the upper and lower sides of the Hall sensor 612. The two second buckles 614 are respectively arranged on the left and right sides of the Hall sensor 612, and are both clamped on the mounting plate 6111, and the opening directions of the two second buckles 614 are radially outwardly distributed.

[0078] Among them, the mounting ring 611 is made of aluminum material, which is conducive to reducing weight; the first buckle 613, the second buckle 614 and the positioning pin 615 are all made of pure iron material and the surface is specially treated, which is conducive to shielding magnetic field interference.

[0079] In addition, magnetic shielding washers 63 are provided on both the upper and lower sides of the mounting ring 611. In this embodiment, the magnetic shielding washers 63 are composed of two pure iron washers and two magnetic shielding washers alternately stacked together.

[0080] In this way, the present invention installs the Hall sensor 612 on the mounting ring 611 through the first clip 613 and the two second clips 614, and realizes reliable limiting of the Hall sensor 612 to prevent its position from deviation; at the same time, the magnetic shielding gasket 63 is used in conjunction with the clip group to magnetically shield the remaining surfaces of the Hall sensor 612 except for the side facing the detection magnetic ring 62, which can protect the Hall sensor 612 only from detecting the magnetic field directly opposite to it, thereby reducing the influence of other magnetic fields on the Hall sensor 612.

[0081] It is worth mentioning that the inlet pipe 12 also includes a magnetic shielding tube 123, which is located between the outer tube 121 and the inner tube 122, and is mounted on the outside of the bearing stator 31 and the sensor assembly 61. It can protect the detection of the two sets of rotor position detection assemblies 6 from interference from the external magnetic field, protect the magnetic bearing 3 from interference from the external magnetic field, and also shield the interference of the magnetic field of the magnetic bearing 3 to the outside world.

[0082] See also Figure 4 and Fig.17 The motor 4 in the present invention is a disc motor, which includes a motor stator 41 and a motor magnetic ring 42. The motor stator 41 is installed in the gap between the outlet tube 13 and the inner tube 122, and includes a second stator yoke 411 and a plurality of second stator teeth 412 axially arranged on the bottom surface of the second stator yoke 411 and distributed in a ring-shaped and equidistant manner, and each second stator tooth 412 is wound with a second coil 413. The motor magnetic ring 42 is installed near the top of the impeller 21 and is sealed by an impeller upper cover plate, and the plurality of second stator teeth 412 are axially arranged opposite to the motor magnetic ring 42.

[0083] The motor magnetic ring 42 is a multi-stage magnetic ring composed of a plurality of fan-shaped permanent magnets. The motor magnetic ring 42 matches the number of motor slots, including but not limited to a 14-pole axial multi-pole magnetized magnetic ring, a 12-pole axial multi-pole magnetized magnetic ring, and a 10-pole axial multi-pole magnetized magnetic ring structure. The motor magnetic ring 42 transmits torque under the alternating magnetic field generated by the motor stator 41 to drive the rotor impeller 2 to rotate and do work.

[0084] As an improvement of the present invention, a plurality of tooth slots 111 are provided at equal intervals in an annular manner at the top of the upper pump chamber of the pump chamber 11, and the ends of the second stator teeth 412 protrude from the second coil 413 and are inserted into the corresponding tooth slots 111. The motor stator 41 of the present invention adopts a lengthened design of the second stator teeth 412, which is beneficial to reducing the air gap between the motor stator 41 and the motor magnetic ring 42, and is beneficial to heat dissipation of the motor stator 41 and increasing the efficiency of the motor.

[0085] See also Figure 2 and Fig.19 A ring groove is provided at the bottom of the pump chamber 11, and the lower chamber magnetic ring 7, the lower chamber magnetic shielding cover and the rear end cover are installed in the ring groove from top to bottom in sequence. The lower chamber magnetic shielding cover is made of pure iron material and is used to shield the magnetic field interference generated by the lower chamber magnetic ring 7 to the outside world; the rear end cover is made of titanium alloy material and is used to seal the lower chamber shielding cover and the lower chamber magnetic ring 7 in the ring groove.

[0086] In addition, an impeller magnetic ring 8 is installed at the bottom of the impeller 21. The lower cavity magnetic ring 7 and the impeller magnetic ring 8 are arranged opposite to each other along the axial direction. Both the lower cavity magnetic ring 7 and the impeller magnetic ring 8 are magnetized along the axial direction, and there is suction between the two to balance the attraction between the motor stator 41 and the motor magnetic ring 42.

[0087] like Fig.11 As shown, in this embodiment, for each magnetic suspension bearing 3, the upper end of the stator magnetic ring 312 located on the upper side is an S pole and the lower end is an N pole, and the upper end of the stator magnetic ring 312 located on the lower side is an N pole and the lower end is an S pole. The permanent magnetic force generated by the stator magnetic rings 312 on the upper and lower sides converges into the stator core 311 to form a main magnetic path, and the main magnetic path is transmitted from the first stator tooth 3111 on the stator core 311 through the air gap between the stator core 311 and the rotor core 321 through the rotor tooth 3211 to the rotor core 321, and then returns to the stator magnetic ring 312 through the first stator yoke 314, so that a closed magnetic circuit can be formed between the stator magnetic rings 312 on the upper and lower sides and the middle stator core 311 and the rotor core 321, and the first stator yoke 314 (such as Fig.11 In the direction indicated by the middle arrow), without being disturbed by external forces, the static bias magnetic field is provided by the permanent magnetic force of the two stator magnetic rings 312, so that the rotor core 321 is in an absolute dynamic suspension state in the axial and radial directions.

[0088] Of course, in other embodiments of the present invention, the magnetic pole directions of all stator magnetic rings 312 may also be set oppositely.

[0089] like Fig.12 As shown, when the rotor impeller 2 is disturbed by external force and deviates axially upward, the static bias magnetic field provided by the permanent magnetic force of the two stator magnetic rings 312 causes the first stator teeth 3111 and the first stator yoke 314 of the stator core 311 to generate an axial downward attraction on the rotor core 321, so that the rotor impeller 2 returns to the origin.

[0090] When the rotor impeller 2 is radially centered, the four Hall sensors 612 detect that the magnetic flux of the detection magnetic ring 62 is approximately equal. Fig.13 As shown, when the rotor impeller 2 is disturbed by external force and deviates radially to the right, the Hall sensor 612 on the right detects the increase of magnetic flux and feeds it back to the control system. The control system controls the current of the first coil 313 on the right to decrease, so as to reduce the attraction of the first stator tooth 3111 to the rotor core 321. If the current of the first coil 313 on the right is reduced to 0, and the rotor impeller 2 is still deviating to the right, the current direction of the first coil 313 on the right is changed to generate a magnetic field opposite to the direction of the main magnetic path, further reducing the attraction of the first stator tooth 3111 to the rotor core 321. At the same time, the current direction of the first coil 313 on the left can also be controlled and increased to generate a magnetic field in the same direction as the main magnetic path, so as to increase the attraction of the first stator tooth 3111 to the rotor core 321, until the Hall sensor 612 detects that the rotor impeller 2 is in the radial center position, the current direction of each first coil 313 is consistent, and the current is reduced to a continuous current that can keep the rotor impeller 2 stable.

[0091] When the rotor impeller 2 deflects in the radial direction, Fig.14As shown, the rotor impeller 2 deflects clockwise by a certain angle, and the Hall sensors 612 at the upper right and lower left both detect an increase in magnetic flux and feed it back to the control system. The control system controls the current of the first coil 313 at the upper right to decrease, so as to reduce the attraction of the first stator tooth 3111 at the upper right to the rotor core 321. When the current of the first coil 313 at the upper right is reduced to 0, if the rotor impeller 2 is still deflecting clockwise, the current direction of the first coil 313 at the upper right is changed to generate a magnetic field opposite to the direction of the main magnetic path, thereby further reducing the attraction of the first stator tooth 3111 at the upper right to the rotor core 321. At the same time, the control system controls the current of the first coil 313 at the lower left to decrease, so as to reduce the attraction of the first stator tooth 3111 at the lower left to the rotor core 321; similarly, if the current of the first coil 313 at the lower left is reduced to 0, and the rotor impeller 2 is still deflected clockwise, the current direction of the first coil 313 at the lower left is changed to generate a magnetic field opposite to the direction of the main magnetic path, further reducing the attraction of the first stator tooth 3111 at the lower left to the rotor core 321. At the same time, the current direction of the first coil 313 at the upper left and lower right can be controlled and increased to generate a magnetic field in the same direction as the main magnetic path, so as to increase the attraction of the first stator tooth 3111 at the upper left and lower right to the rotor core 321, until the Hall sensor 612 detects that the rotor impeller 2 is in the radial center position, the current direction of each first coil 313 is consistent, and the current is reduced to a continuous current that can keep the rotor impeller 2 stable.

[0092] Embodiment 2

[0093] The difference between this embodiment and the first embodiment is that the structure of the bearing rotor 32 is different.

[0094] Specifically, see Fig. 20 and Fig.21 The bearing rotor 32 also includes rotor magnetic rings 322 distributed at both axial ends of the rotor core 321. In a magnetic suspension bearing 3, the stator magnetic ring 312 and the rotor magnetic ring 322 located on the same side of the axial direction are distributed radially opposite to each other. The two rotor magnetic rings 322 located at both axial ends of the rotor core 321 are magnetized axially and in opposite directions, and the magnetization direction of any rotor magnetic ring 322 is also opposite to the magnetization direction of a stator magnetic ring 312 radially opposite to it.

[0095] The axial force of the rotor impeller 2 in this embodiment is controlled by the permanent magnetic force between the stator magnetic ring 312 and the rotor magnetic ring 322. Since both the stator magnetic ring 312 and the rotor magnetic ring 322 are axially magnetized, and the magnetization directions of the stator magnetic ring 312 and the rotor magnetic ring 322 on the same side are opposite, once the rotor impeller 2 is axially offset relative to the origin, due to the interaction force between the stator magnetic ring 312 and the rotor magnetic ring 322, a force will be generated in the axial direction to restore the rotor impeller 2 to the origin. In this structure, whether the rotor impeller 2 is axially upward or axially downward, a force will be generated in the axial direction to restore the origin, so that the rotor impeller 2 is axially suspended.

[0096] The radial force of the rotor impeller 2 in this embodiment is mainly controlled by the permanent magnetic force between the stator magnetic ring 312 and the rotor magnetic ring 322. The permanent magnetic force generated by the two stator magnetic rings 312 at the upper and lower ends of the stator core 311 converges into the stator core 311 to form a main magnetic path. The main magnetic path is transmitted from the first stator tooth 3111 on the stator core 311 through the air gap between the stator core 311 and the rotor core 321 to the rotor core 321, and then to the rotor magnetic ring 322. Therefore, a closed magnetic circuit can be formed between the stator magnetic rings 312 and the rotor magnetic ring 322 on the upper and lower sides and the stator core 311 and the rotor core 321, so as to drive the inner rotor group to suspend radially. At the same time, by controlling the current direction and magnitude of the first coil 313, the attraction of the first stator tooth 3111 to the rotor core 321 is controlled, which serves as an auxiliary control force.

[0097] It can be seen that this embodiment adopts the form of a combination of permanent magnet and electromagnet, and uses the permanent magnetic force between the stator magnetic ring 312 and the rotor magnetic ring 322 to provide a static bias magnetic field, and uses the electromagnet composed of the first stator tooth 3111 and the first coil 313 as a dynamic suspension auxiliary adjustment, which not only maintains the low power consumption characteristics of the permanent magnet bearing, but also realizes high-precision suspension and adjustment through electromagnetic control, and realizes five-degree-of-freedom suspension. It can not only reduce the bias current required for electromagnetic control and significantly reduce the power consumption of the system, making the blood pump more advantageous in application scenarios that require long-term operation or limited energy supply, but also enables the blood pump to have a higher load-bearing capacity and better stability, and can adapt to various complex working conditions.

[0098] In this embodiment, permanent magnet rings are provided at the upper and lower ends of the stator core 311 and the rotor core 321, and the permanent magnet rings on the upper and lower sides can form two closed magnetic circuits through the first stator teeth 3111 of the middle stator core 311 and the rotor core 321, so that the magnetic force utilization rate is higher. Under the same magnetic force requirement, the volume can be smaller and the structure is more compact, and a stable static bias magnetic field can be provided. At the same time, the bias current required for electromagnetic control is small, thereby realizing a five-degree-of-freedom permanent magnet biased magnetic suspension bearing 3 with low power consumption, small volume and light weight. Under the premise of ensuring blood compatibility and long-term reliability, more efficient energy utilization and more compact structural design can be achieved to improve the overall performance and clinical applicability of the blood pump.

[0099] In addition, the bearing rotor 32 also includes two rotor yokes 323, which are respectively fixed on the ends of the two rotor magnetic rings 322 located at the axial ends of the rotor core 321 and facing away from each other, and the two rotor yokes 323 both have an annular second outer flange 3231 extending radially outward, and the two second outer flanges 3231 correspond one by one to the inner flanges 3141 of the two first stator yokes 314, are relatively distributed in the radial direction and are clearance-matched, so as to reduce the magnetic field air gap between the first stator yoke 314 and the rotor yoke 323, thereby improving the magnetic force conduction efficiency.

[0100] Embodiment 3

[0101] See also Fig. 22 The difference between this embodiment and the second embodiment is that the bearing stator 31 in this embodiment does not have the first stator yoke 314, and the bearing rotor 32 does not have the rotor yoke 323. It can also achieve five-degree-of-freedom suspension, reduce the bias current required for electromagnetic control, and significantly reduce the power consumption of the system.

[0102] Many specific details are described in the above description to facilitate a full understanding of the present invention. However, the above description is only a preferred embodiment of the present invention. The present invention can be implemented in many other ways different from those described herein, so the present invention is not limited to the specific implementation disclosed above. At the same time, any person familiar with the art can make many possible changes and modifications to the technical solution of the present invention using the methods and technical contents disclosed above without departing from the scope of the technical solution of the present invention, or modify it into an equivalent embodiment of equivalent changes. Any simple modification, equivalent change and modification made to the above embodiments according to the technical essence of the present invention without departing from the content of the technical solution of the present invention still falls within the scope of protection of the technical solution of the present invention.

Claims

1. A five-degree-of-freedom permanent magnet biased magnetic suspension blood pump, comprising a pump housing (1), a rotor impeller (2), a magnetic suspension bearing (3) and a motor (4) for driving the rotor impeller (2) to rotate and perform work, wherein the pump housing (1) comprises a pump chamber (11) and an inlet pipe (12) fixedly arranged at the top of the pump chamber (11) and connected to the pump chamber (11), the rotor impeller (2) comprises an impeller (21) and a pump rotor (22) fixedly arranged at the top of the impeller (21), the impeller (21) is accommodated in the pump chamber (11), and the pump rotor (22) extends into the inlet pipe (12); Features: The magnetic bearing (3) comprises a bearing stator (31) and a bearing rotor (32); the bearing stator (31) is fixed in the inlet pipe (12), and comprises an annular stator core (311) and stator magnetic rings (312) distributed at two axial ends of the stator core (311); a plurality of first stator teeth (3111) distributed in an annular manner and at equal intervals are radially arranged on the inner wall of the stator core (311), and a first coil (313) is wound around each of the first stator teeth (3111); the bearing rotor (32) is fixed in the pump rotor (22); The bearing rotor (32) comprises a rotor core (321), and rotor teeth (3211) are arranged on the outer circumferential surface of the rotor core (321). The plurality of first stator teeth (3111) are arranged radially opposite to the rotor teeth (3211). The stator magnetic rings (312) located at the axial ends of the stator core (311) are magnetized in the axial direction and in opposite directions, and a closed magnetic circuit can be formed between the stator magnetic ring (312) and the stator core (311) and the rotor core (321).

2. The five-degree-of-freedom permanent magnet biased magnetic levitation blood pump according to claim 1, characterized in that: The bearing stator (31) further comprises two first stator yokes (314), the two first stator yokes (314) being respectively fixed on the ends of the stator magnetic ring (312) located at the two axial ends of the stator core (311) facing away from each other, and the two first stator yokes (314) both have an annular inner flange (3141) extending radially inward, and the two ends of the rotor core (321) have an annular first outer flange (3212) extending radially outward, and the two inner flanges (3141) and the two first outer flanges (3212) are distributed radially opposite to each other and are clearance-matched.

3. The five-degree-of-freedom permanent magnet biased magnetic levitation blood pump according to claim 1, characterized in that: The bearing rotor (32) further comprises rotor magnetic rings (322) distributed at two axial ends of the rotor core (321), and the stator magnetic ring (312) and the rotor magnetic ring (322) located on the same side in the axial direction are distributed relative to each other in the radial direction; The rotor magnetic rings (322) located at the axial ends of the rotor core (321) are magnetized along the axial direction and in opposite directions. At the same time, the magnetization direction of any rotor magnetic ring (322) is also opposite to the magnetization direction of a stator magnetic ring (312) radially opposite to it.

4. The five-degree-of-freedom permanent magnet biased magnetic levitation blood pump according to claim 3, characterized in that: The bearing rotor (32) further comprises two rotor yokes (323), the two rotor yokes (323) being respectively fixed on ends of the rotor magnetic ring (322) located at two axial ends of the rotor core (321) and facing away from each other, and both of the two rotor yokes (323) are provided with an annular second outer flange (3231) extending radially outward; The bearing stator (31) further comprises two first stator yokes (314), the two first stator yokes (314) being respectively fixed on the ends of the stator magnetic ring (312) located at the two axial ends of the stator core (311) facing away from each other, and the two first stator yokes (314) are both provided with an annular inner flange (3141) extending radially inward, and the two inner flanges (3141) and the two second outer flanges (3231) are distributed radially opposite to each other and are clearance-matched.

5. The five-degree-of-freedom permanent magnet biased magnetic suspension blood pump according to any one of claims 1 to 4, characterized in that: The rotor teeth (3211) are provided with a plurality of teeth (31111) arranged and distributed in an axial direction at intervals, and the inner side surface of each of the first stator teeth (3111) is provided with a plurality of teeth (31111) which are the same in number as the rotor teeth (3211) and are distributed one by one.

6. The five-degree-of-freedom permanent magnet biased magnetic levitation blood pump according to any one of claims 1 to 4, characterized in that: The magnetic suspension bearing (3) is configured with at least two magnetically non-conductive washers (5) arranged and distributed along the axial direction, and between two adjacent bearing stators (31) and two adjacent bearing rotors (32), non-magnetic washers (5) are installed.

7. The five-degree-of-freedom permanent magnet biased magnetic levitation blood pump according to claim 1, characterized in that: The invention also comprises two groups of rotor position detection components (6), each of which comprises a sensor component (61) and a detection magnetic ring (62). The upper and lower ends of the inlet pipe (12) are each equipped with one sensor component (61), and the upper and lower ends of the pump rotor (22) are each equipped with one detection magnetic ring (62). The two sensor components (61) and the two detection magnetic rings (62) are used in a one-to-one correspondence to detect the position of the pump rotor (22).

8. The five-degree-of-freedom permanent magnet biased magnetic suspension blood pump according to claim 7, characterized in that: The sensor assembly (61) comprises a mounting ring (611), a plurality of Hall sensors (612) and a plurality of buckle groups, wherein the number of the Hall sensors (612) and the buckle groups is the same as that of the first coil (313) and corresponds one to one; the mounting ring (611) is provided with a plurality of mounting grooves at equal intervals in an annular manner, and a mounting plate (6111) is formed in each of the mounting grooves, and the plurality of Hall sensors (612) are respectively mounted on the plurality of mounting plates (6111) in a one-to-one correspondence via the plurality of buckle groups; The buckle group comprises a first buckle (613) and two second buckles (614) both of which are U-shaped; the first buckle (613) is fixed to the mounting plate (6111) by a positioning pin (615), and its opening direction is distributed radially inward, and at the same time, the two claws on the first buckle (613) are respectively clamped on the upper and lower sides of the Hall sensor (612); the two second buckles (614) are respectively arranged on the left and right sides of the Hall sensor (612), and are both clamped on the mounting plate (6111), and the opening directions of the two second buckles (614) are distributed radially outward; Magnetic shielding washers (63) are provided on both the upper and lower sides of the mounting ring (611), and the magnetic shielding washers (63) are used together with the buckle assembly to magnetically shield the remaining surfaces of the Hall sensor (612) except for a side facing the detection magnetic ring (62).

9. The five-degree-of-freedom permanent magnet biased magnetic levitation blood pump according to claim 1, characterized in that: The motor (4) comprises a motor stator (41) mounted on the top of the pump chamber (11) and a motor magnetic ring (42) mounted on the impeller (21); the motor stator (41) comprises a second stator yoke (411) and a plurality of second stator teeth (412) axially arranged on the bottom surface of the second stator yoke (411) and distributed in an annular shape with equal spacing, and a second coil (413) is wound around each of the second stator teeth (412); a plurality of tooth slots (111) are arranged in an annular shape with equal spacing on the top of the pump chamber (11); ends of the second stator teeth (412) protrude from the second coil (413) and are inserted into corresponding tooth slots (111), and are arranged axially opposite to the motor magnetic ring (42).

10. The five-degree-of-freedom permanent magnet biased magnetic levitation blood pump according to claim 1, characterized in that: A lower chamber magnetic ring (7) is installed at the bottom of the pump chamber (11), and an impeller magnetic ring (8) is installed at the bottom of the impeller (21); the lower chamber magnetic ring (7) and the impeller magnetic ring (8) are arranged opposite to each other in the axial direction, and there is suction between the two.

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