CN112494803A

CN112494803A - Blood pump

Info

Publication number: CN112494803A
Application number: CN202011525064.5A
Authority: CN
Inventors: 余顺周
Original assignee: Individual
Current assignee: Shenzhen Core Medical Technology Co Ltd
Priority date: 2020-12-22
Filing date: 2020-12-22
Publication date: 2021-03-16

Abstract

The invention provides a blood pump, which comprises a sleeve, an impeller arranged in the sleeve and a driving unit for rotating the impeller, wherein the sleeve is provided with a blood flow inlet and a blood flow outlet; the drive unit comprises a shell, and a rotor and a stator which are arranged in the shell, the proximal end of the sleeve is connected to the shell, the rotor comprises a rotating shaft, and the rotating shaft extends out of the shell and is connected with the impeller; the rotor is characterized by further comprising at least two magnets which are arranged on the rotating shaft at intervals along the axial direction, the stator is arranged around the rotating shaft and located between the two magnets, and a rotating magnetic field generated by the stator interacts with the two magnets respectively to enable the rotating shaft to rotate. The blood pump can increase the output power and the load torque of the driving unit of the blood pump on the basis of reducing the overall radial size of the blood pump.

Description

Blood pump

Technical Field

The invention relates to the field of medical devices, in particular to a blood pump which is inserted into a blood vessel of a patient through skin.

Background

Intravascular blood pumps, designed for percutaneous insertion into a patient's blood vessel, such as the blood vessels of the arteries or veins of the thigh or armpit, may be advanced into the patient's heart to function as either a left ventricular assist device or a right ventricular assist device. Accordingly, intravascular blood pumps may also be referred to as intracardiac blood pumps.

The intravascular blood pump mainly comprises an impeller and a motor for driving the impeller to rotate, and when the impeller rotates, blood is conveyed from a blood inflow port of the blood pump to a blood outflow port. Specifically, the motor generates a rotating magnetic field when working, and the impeller is provided with a magnet which interacts with the rotating magnetic field to enable the impeller to rotate around the axis of the impeller. However, the magnets on the impeller can increase the weight of the impeller, reducing the pumping efficiency of the impeller; furthermore, the size and shape of the impeller is limited by the magnets thereon, which increases the difficulty of machining the impeller.

Disclosure of Invention

In view of at least one of the above-mentioned drawbacks, it is necessary to provide a blood pump with high pumping efficiency.

The invention provides a blood pump, which comprises a sleeve, an impeller arranged in the sleeve and a driving unit for rotating the impeller, wherein the sleeve is provided with a blood flow inlet and a blood flow outlet; the drive unit comprises a shell, and a rotor and a stator which are arranged in the shell, the proximal end of the sleeve is connected to the shell, the rotor comprises a rotating shaft, and the rotating shaft extends out of the shell and is connected with the impeller; the rotor is characterized by further comprising at least two magnets which are arranged on the rotating shaft at intervals along the axial direction, the stator is arranged around the rotating shaft and located between the two magnets, and a rotating magnetic field generated by the stator interacts with the two magnets respectively to enable the rotating shaft to rotate.

In the blood pump of the invention, the stator comprises a plurality of columns arranged around the axis of the rotating shaft and a coil winding arranged around the periphery of each column, and the columns comprise a rod part, a first head part and a second head part which are respectively arranged at two ends of the rod part;

the two magnets are respectively a first magnet and a second magnet, the first magnet is opposite to the first head, and the second magnet is opposite to the second head.

In the blood pump of the present invention, the axial distance between the first magnet and the column is 0.1mm to 2 mm; and/or the axial distance between the second magnet and the column is 0.1-2 mm.

In the blood pump of the present invention, the rotor further includes at least two flywheels provided on the rotating shaft, and the two magnets are respectively fixed to the corresponding flywheels.

In the blood pump of the present invention, the flywheel has a disk-shaped structure, and the magnet is mounted on a side of the flywheel facing the stator.

In the blood pump of the present invention, a positioning structure is disposed at a position of the housing close to the flywheel, and a connection line of the coil winding is fixed in the positioning structure.

In the blood pump of the present invention, the rotor includes three flywheels axially spaced and disposed on the rotating shaft, and the flywheels are respectively a first flywheel, a second flywheel and a third flywheel, the first flywheel is equipped with a first magnet, the second flywheel is equipped with a second magnet and a third magnet, and the third flywheel is equipped with a fourth magnet;

the stator comprises a first stator and a second stator which are arranged along the axial direction, the first stator is positioned between the first magnet and the second magnet, and the second stator is positioned between the third magnet and the fourth magnet; the first stator and the second stator each include a plurality of legs arranged around an axis of the rotating shaft, and a coil winding around an outer periphery of each of the legs.

In the blood pump of the present invention, the housing includes a first housing sleeved outside the distal end of the rotor, a second housing sleeved outside the proximal end of the rotor, and a third housing sleeved outside the stator;

two ends of the third shell are respectively connected to the first shell and the second shell; the first shell is internally provided with a through hole, and the rotating shaft extends to the outside of the first shell and is fixedly connected with the impeller through the through hole.

In the blood pump of the present invention, the drive unit further includes a distal bearing and a proximal bearing respectively connected to the rotating shaft, and a control member electrically connected to the coil winding of the stator;

the distal bearing is fixed within the first housing and the proximal bearing is fixed within the second housing; the control piece is fixed in the first shell and/or the second shell, the control piece is provided with a mounting hole, and the rotating shaft penetrates through the mounting hole.

In the blood pump of the invention, the magnet is composed of a plurality of magnetic units arranged around the axis of the rotating shaft, and two adjacent magnetic units are arranged at intervals.

In conclusion, the blood pump disclosed by the invention has the following beneficial effects: the rotating magnetic field that the stator produced interacts with two magnets respectively, and it is rotatory through two magnet drive pivots, and the pumping efficiency of impeller is improved to the load torque and the power of the improvement pivot that can be very big.

Further, compared with the method that the magnet is directly arranged on the impeller, the magnet is arranged on the rotating shaft, so that the axial distance between the magnet and the stator is not interfered by other parts, particularly the axial distance between the impeller and the shell and the thickness of the shell are influenced, and a smaller axial distance is easily obtained between the magnet and the stator. When the axial distance between the magnet and the stator becomes smaller, the magnetic density between the magnet and the stator is increased, and the output power and the torque of the driving unit are increased. And, because the magnet setting is in the pivot for the size and the shape design of this application impeller do not receive the influence of magnet, and the design of impeller is more nimble, has reduced the processing degree of difficulty of impeller. In addition, this application makes magnet and stator along the setting of axial interval, adopts axial magnetic flux direct drive's mode drive pivot rotatory, can reduce drive unit's radial dimension. That is, the present application can increase the output power and the load torque of the drive unit on the basis of reducing the overall radial dimension of the drive unit.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings needed to be used in the description of the embodiments of the present invention will be briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art that other drawings can be obtained according to these drawings without inventive exercise.

Fig. 1 is a perspective view of a blood pump provided in accordance with a first embodiment of the present invention;

FIG. 2 is an exploded view of the blood pump of FIG. 1;

FIG. 3 is a cross-sectional view of the impeller and drive unit connection of the blood pump of FIG. 1;

FIG. 4 is an exploded view of the impeller and drive unit of the blood pump of FIG. 3;

FIG. 5 is an exploded view of the rotor and stator of the drive unit shown in FIG. 3;

FIG. 6 is a schematic view of the rotor shaft and flywheel of the rotor shown in FIG. 5;

FIG. 7 is an exploded view of the stator shown in FIG. 5;

FIG. 8 is an exploded view of the housing of the drive unit shown in FIG. 3;

FIG. 9 is a schematic view of a second housing of the housing of FIG. 8;

FIG. 10 is a cross-sectional view of an impeller and drive unit of a blood pump provided in accordance with a second embodiment of the present invention;

FIG. 11 is an exploded view of the stator and rotor of the drive unit of FIG. 10;

FIG. 12 is an exploded view of the impeller and drive unit shown in FIG. 10;

FIG. 13 is an exploded view of the post of the stator shown in FIG. 12;

fig. 14 is an exploded view of the housing of the drive unit shown in fig. 12.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, not all, embodiments of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

It will be understood that when an element is referred to as being "secured to" another element, it can be directly on the other element or intervening elements may also be present. When a component is referred to as being "connected" to another component, it can be directly connected to the other component or intervening components may also be present.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used in the description of the invention herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.

In the field of interventional medicine, it is generally defined that the end of the instrument proximal to the operator is the proximal end and the end distal to the operator is the distal end.

Referring to fig. 1 and 2, a blood pump 100 according to a first embodiment of the present invention includes at least an impeller 10, a drive unit 20, a cannula 30, and a catheter 40. The distal end of the catheter 40 is connected to the proximal end of the drive unit 20 and the proximal end of the cannula 30 is connected to the distal end of the drive unit 20. The impeller 10 is disposed within the casing 30 in rotational connection with the drive unit 20.

The conduit 40 is used for accommodating a supply line, such as a cleaning line, a wire electrically connected to the driving unit 20, and the like. The cannula 30 is provided with a blood inlet 31 and a blood outlet 32, and when the impeller 10 is operated, blood enters the cannula 30 through the blood inlet 31 and is discharged from the blood outlet 32 along the blood flow path in the cannula 30.

Referring to fig. 3, the driving unit 20 at least includes a housing 21, and a rotor 22 and a stator 23 disposed in the housing 21.

The rotor 22 includes a rotating shaft 221, and two magnets 223 mounted on the rotating shaft 221 in an axially spaced manner. The distal end of the rotating shaft 221 extends out of the housing 21 and is fixedly connected with the impeller 10, and the two magnets 223 are located in the housing 21.

The stator 23 is disposed around the rotation shaft 221 between the two magnets 223, and the rotating magnetic fields generated by the stator 23 interact with the two magnets 223, respectively, to rotate the rotation shaft 221.

Since the rotating magnetic field generated by the stator 23 interacts with the two magnets 223 respectively, the two magnets 223 drive the rotating shaft 221 to rotate, so that the load torque and power of the rotating shaft 221 can be greatly improved, and the pumping efficiency of the impeller 10 can be improved.

Further, compared with the arrangement of the magnet directly on the impeller, the arrangement of the magnet 223 on the rotating shaft 221 in the present application can make the axial distance between the magnet 223 and the stator 23 not interfered by other components, especially the axial distance between the impeller 10 and the casing 21 and the thickness of the casing 21, so that a smaller axial distance between the magnet 223 and the stator 23 can be easily obtained. When the axial distance between the magnet 223 and the stator 23 becomes smaller, the magnetic density between the magnet 223 and the stator 23 increases, and the output power and the torque of the driving unit 20 increase accordingly. In addition, the magnet 223 is arranged on the rotating shaft 221, so that the size and shape design of the impeller 10 is not affected by the magnet, the design of the impeller 10 is more flexible, and the processing difficulty of the impeller 10 is reduced.

In addition, the magnet 223 and the stator 23 are arranged at intervals along the axial direction, and the rotating shaft 221 is driven to rotate by adopting a mode of direct drive of axial magnetic flux, so that the radial dimension of the driving unit 20 can be reduced. That is, the present application can increase the output power and the load torque of the drive unit 20 on the basis of reducing the overall radial dimension of the drive unit 20.

The structure of the drive unit 20 will be specifically described below.

Referring to fig. 4, the driving unit 20 includes a housing 21, and a rotor 22, a stator 23, a distal bearing 24, a proximal bearing 25 and a control member 26 respectively installed in the housing 21.

Referring to fig. 5, the rotor 22 includes a rotating shaft 221, two flywheels 222, and two magnets 223.

Wherein, the distal end of the rotating shaft 221 extends out of the casing 21 and is fixedly connected with the impeller 10. The two flywheels 222 are axially spaced, and respectively include a first flywheel 222a and a second flywheel 222b, and each flywheel 222 is fixed on the rotating shaft 221 and extends in a radial direction toward a side away from the rotating shaft 221. The two magnets 223 are a first magnet 223a and a second magnet 223b, respectively, the first magnet 223a is fixed on the side of the first flywheel 222a facing the second flywheel 222b, and the second magnet 223b is fixed on the side of the second flywheel 222b facing the first flywheel 222 a. The stator 23 is located between the first magnet 223a and the second magnet 223b, and the rotating magnetic field generated by the stator 23 interacts with the two magnets 223 respectively, so that the magnets 223 and the flywheel 222 fixedly connected with the magnets 223 rotate together, thereby driving the rotating shaft 221 to rotate.

Specifically, each magnet 223 is formed by surrounding a plurality of magnetic units, and two adjacent magnetic units are arranged at intervals. If the gap between two adjacent magnetic units is too small, the innermost magnetic field extending between the two adjacent magnetic units cannot interact with the rotating magnetic field generated by the stator 23, and affects the rotation speed of the rotating shaft 221. Therefore, the present invention allows the adjacent two magnetic units to be spaced apart from each other, and adjusts the size of the gap between the adjacent two magnetic units according to the size of the axial distance between the magnet 223 and the stator 23.

In the present embodiment, the magnet 223 is composed of six magnetic units arranged at intervals around the axis of the rotating shaft 221. Each magnetic unit is a sector magnet, making the magnet 223a generally circular ring-shaped structure. It will be appreciated that in other embodiments, the magnet 223 may also be comprised of more or fewer magnetic elements, such as two, four, eight, or ten, etc.

Referring to fig. 6, each flywheel 222 includes a main body 2221 and a mounting boss 2222.

The main body portion 2221 has a generally disk-shaped structure, preferably a disk-shaped structure, which is fixed to the rotation shaft 221 to extend in a radial direction toward a side away from the rotation shaft 221. The magnet 223 is fixed to the side of the body portion 2221 facing the stator 23.

The mounting boss 2222 is located on a side of the body portion 2221 facing the stator 23, and the magnet 223 is disposed around an outer circumference of the mounting boss 2221. Specifically, one end of the mounting boss 2222 is fixed to the main body 2221, and the other end extends toward a side away from the main body 2221, and the outer diameter of the mounting boss 2222 is greater than the outer diameter of the rotating shaft 221 but smaller than the outer diameter of the main body 2221. By providing the mounting boss 2221 on the main body 2221, the magnet 223 can be conveniently assembled and positioned, so that the magnet 223 can be better fixed on the main body 2221.

According to the present invention, the flywheel 222 is disposed on the rotating shaft 221, and the magnet 223 is fixed on the corresponding flywheel 222, and the rotating shaft 221 is driven to rotate by the flywheel 222, such that the connection strength between the magnet 223 and the rotating shaft 221 can be increased, and the stability of the rotation of the rotating shaft 221 can be improved.

In this embodiment, the flywheel 222 and the rotating shaft 221 are integrally formed. In other embodiments, the flywheel 222 can be fixedly connected to the rotating shaft 221 by other means, such as adhesion, welding, etc.

It should be understood that the flywheel 222 of the present embodiment is only used as an example and is not limited to the present application, and the flywheel 222 of the present application may have other structures as long as the magnet 223 can be fixed on the rotating shaft 221. For example, in other embodiments, the flywheel 222 only includes the main body 2221, and the magnet 223 is fixed to a side of the main body 2221 facing the stator 23; alternatively, the flywheel 222 includes only the mounting boss 2222, and the magnet 223 is fixed on the outer circumferential surface of the mounting boss 2222; alternatively, the flywheel 222 is composed of a plurality of support rods spaced around the axis of the rotating shaft 221, one end of each support rod is fixed on the rotating shaft 221, the other end of each support rod extends in the radial direction to the first side far away from the rotating shaft 221, the number of the support rods is the same as that of the magnetic units, and one side of each support rod close to the stator 23 is fixed with one magnetic unit.

It is also understood that in other embodiments, the flywheel 222 may not be disposed on the rotating shaft 221, and the magnet 223 is directly fixed on the rotating shaft 221; or the rotation shaft 221 is provided with a fixing groove in which the magnet 223 is fitted.

Referring to fig. 7, the stator 23 includes a plurality of legs 231 arranged around the axis of the shaft 221, and a coil winding 232 wound around the outer circumference of each of the legs 231. The stator 23 has a passage extending through the center thereof in the axial direction, and the rotating shaft 221 rotatably passes through the passage.

Wherein, a plurality of posts 231 are arranged around the axis of the rotating shaft 221, and form a circular ring-like structure, and the rotating shaft 221 passes through the center of the circular ring-like structure. The post 231 serves as a magnetic core and is made of a soft magnetic material such as cobalt steel or the like. The post 231 is located between the two magnets 223 and is axially spaced from the two magnets 223, respectively. The axial distance between the column 231 and the first magnet 223a is 0.1mm to 2mm, preferably 0.1mm to 0.5 mm; and/or the axial distance between the post 231 and the second magnet 223b is 0.1mm to 2mm, preferably 0.1mm to 0.5 mm.

It should be noted that, when the end surface of the magnet 223 or the post 231 is a bevel or a non-flat surface, the "axial distance" between the post 231 and the magnet 223 refers to the axial distance between the point at the most proximal end of the magnet 223 and the point at the most distal end of the post 231; alternatively, the axial distance between the point of the magnet 223 that is farthest from the point of the post 231 that is closest to the post. The magnet 223 and the column 231 are axially arranged on the rotating shaft 221 at intervals, and the axial distance between the magnet 223 and the column 231 is set to be 0.1-2 mm, so that the magnet 223 and the column 231 have larger magnetic density, and the output power of the driving unit 20 is increased.

Specifically, each post 231 includes a stem portion 2311 and head portions 2312 disposed at opposite ends of the stem portion 2311. The two heads 2312 are a first head 2312a and a second head 2312b, respectively. The first head 2312a is opposite the first magnet 223a and the second head 2312b is opposite the second magnet 223 b.

The coil winding 232 includes a plurality of coils 2321, the number of coils 2321 is the same as the number of posts 231, and the outer circumference of each rod 2311 is surrounded by a corresponding coil 2321. The coil windings 232 are sequentially controlled by a control unit (not shown) to create a rotating magnetic field for driving the magnets 223.

Referring to fig. 8, the housing 21 includes a first housing 211, a second housing 212, and a third housing 213.

The first housing 211 is disposed outside the distal end of the rotor 22, the second housing 212 is disposed outside the proximal end of the rotor 222, and the third housing 213 is disposed outside the stator 23.

The first housing 211 is substantially an open-ended structure with the other end closed, and is sleeved outside the distal end of the rotor 22, and the distal end of the rotating shaft 221 passes through the first housing 211 and is connected to the impeller 10.

Along the direction from the proximal end to the distal end of the first housing 211, a first connection groove 2110, a first installation groove 2111, a first limit groove 2112, a second limit groove 2113 and a through hole 2114 are disposed in the first housing 211.

Wherein the first coupling groove 2110 is used to couple with the third housing 213. In assembling, the distal end connector 2131 of the third housing 213 is inserted into the first connecting groove 2110 to fixedly connect the first housing 211 and the third housing 213.

The first mounting groove 2111 is used for accommodating the first magnet 223a and the first flywheel 222a, and the first magnet 223a and the first flywheel 222a are rotatably accommodated in the first mounting groove 2111. The inner diameter of the first mounting groove 2111 is larger than the outer diameters of the first magnet 223a and the first flywheel 222a, so that the first magnet 223a and the first flywheel 222a are prevented from touching the inner wall of the first mounting groove 2111 during rotation.

The first retaining groove 2112 is used for accommodating the control member 26, and the control member 26 is fixed in the first retaining groove 2112. In this embodiment, the control member 26 includes three PCB boards, one of which is fixed in the first retaining groove 2112, and the other two of which are fixed in the second housing 212. The connection lines of the coil windings 232 are connected to the corresponding PCB boards, respectively. Each PCB is provided with a mounting hole, the mounting hole is in clearance fit with the rotating shaft 221, and the rotating shaft 221 can rotatably penetrate through the mounting hole. It is understood that the present embodiment is not limited to the specific number of PCB boards, and one, two or more PCB boards may be provided as required.

The second retaining groove 2113 is configured to receive the distal bearing 24, and the distal bearing 24 is fixed in the second retaining groove 2113. Wherein the distal bearing 24 abuts against the side wall of the second retaining groove 2113, preventing the distal bearing 24 from moving in the radial direction. As shown in fig. 6, the rotating shaft 221 is provided with a distal end limiting portion 2211, the distal end limiting portion 2211 is engaged with the bottom wall of the second limiting groove 2113, so as to limit the distal end bearing 24 between the distal end limiting portion 2211 and the second limiting groove 2113, and prevent the distal end bearing 24 from moving in the axial direction.

The through hole 2114 is for the distal end of the shaft 221 to pass through. The through hole 2114 is in clearance fit with the rotating shaft 221, and the distal end of the rotating shaft 221 extends out of the casing 21 through the through hole 2114 and is fixedly connected with the impeller 10.

Referring to fig. 8 and 9, the second housing 212 is generally an open-ended structure with the other end closed, and is disposed over the proximal end of the rotor 22.

In the direction from the distal end to the proximal end of the second housing 212, a second connecting groove 2120, a second mounting groove 2121, a third limiting groove 2122, a fourth limiting groove 2123 and a connecting hole 2124 are disposed in the second housing 212.

Wherein the second connecting slot 2120 is used for connecting with the third housing 213. When assembling, the proximal connector 2132 of the third housing 213 is inserted into the second connecting groove 2110, so that the second housing 212 and the third housing 213 are fixedly connected.

The second mounting groove 2121 is used for accommodating the second magnet 223b and the second flywheel 222b, and the second magnet 223b and the second flywheel 222b are rotatably accommodated in the second mounting groove 2121. The inner diameter of the second mounting groove 2121 is larger than the outer diameters of the second magnet 223b and the second flywheel 222b, so that the second magnet 223b and the second flywheel 222b are prevented from touching the inner wall of the second mounting groove 2121 during rotation.

The third limiting groove 2122 is used for accommodating the control element 26, and the control element 26 is fixed in the third limiting groove 2122. In this embodiment, the control component 26 includes three PCB boards, one of the three PCB boards is fixed in the first retaining groove 2112 of the first housing 211, and the other two PCB boards are axially stacked and fixed in the third retaining groove 2122 of the second housing 212.

The fourth limiting groove 2123 is used for accommodating the proximal bearing 25, and the proximal bearing 25 is fixed in the fourth limiting groove 2123. The proximal bearing 25 abuts against the side wall of the fourth retaining groove 2123 to prevent the proximal bearing 25 from moving in the radial direction. As shown in fig. 4 and 6, the rotating shaft 221 is provided with a proximal end limiting portion 2212, the proximal end limiting portion 2212 is engaged with the bottom wall of the fourth limiting groove 2123, so as to limit the proximal bearing 25 between the proximal end limiting portion 2212 and the fourth limiting groove 2123, and prevent the proximal bearing 25 from moving axially.

The connection hole 2124 is used for passing supply lines (e.g., a cleaning line, and a wire electrically connected to the PCB board) in the guide duct 40. In the embodiment shown in fig. 9, the connection holes 2124 include three, and each connection hole 2124 axially penetrates the second housing 212.

Referring to fig. 8 again, the third housing 213 is substantially a structure with two open ends, and is disposed outside the stator 23.

A distal connector 2131 and a proximal connector 2132 are respectively provided at both ends of the third housing 213. When assembling, the distal connector 2131 is inserted into the first connecting groove 2110 of the first housing 211, and the proximal connector 2132 is inserted into the second connecting groove 2120 of the second housing 212.

It should be understood that the housing 21 of the present embodiment is only used as an example, and is not limited to the present application, and the housing 21 of the present application may also have other structures as long as it can be sleeved outside the stator 23 and the rotor 22 to play a role in sealing the stator 23 and the rotor 22. For example, in other embodiments, the housing 21 includes a first housing 211 that fits over the distal end of the rotor 22, a second housing 212 that fits over the proximal end of the rotor 22, and a third housing 213 that fits over the stator 23. The third housing 213 and the second housing 212 are integrated, or the third housing 213 and the first housing 211 are integrated.

Referring to fig. 10 and 11, a second embodiment of the present invention provides a blood pump 100, which at least comprises an impeller 10, a drive unit, a cannula and a catheter. The driving unit includes at least a housing 21, and a rotor 22 and a stator 23 disposed in the housing 21. The rotor 22 includes a rotating shaft 221, and the rotating shaft 221 extends out of the casing 21 and is connected to the impeller 10.

The second embodiment is different from the first embodiment in that the rotor 22 includes three flywheels, namely a first flywheel 222a, a second flywheel 222b and a third flywheel 222c, axially spaced from each other and disposed on the rotating shaft 221. The first flywheel 222a is provided with a first magnet 223a, the second flywheel 222b is provided with a second magnet 223b and a third magnet 223c, and the third flywheel 222c is provided with a fourth magnet 223 d.

The stator 23 includes two, first and

second stators

23a and 23b, respectively. The first stator 23a is positioned between the first magnet 223a and the second magnet 223b, and the rotating magnetic field generated by the first stator 23a interacts with the first magnet 223a and the second magnet 223b, respectively, to rotate the rotating shaft 221. The second stator 23b is positioned between the third magnet 223c and the fourth magnet 223d, and the rotating magnetic field generated by the second stator 23b interacts with the third magnet 223c and the fourth magnet 223d, respectively, to rotate the rotating shaft 221.

Compared with the first embodiment, the second embodiment adopts two stators 23 to drive the three flywheels 222 to rotate, which can greatly increase the rotation speed of the rotating shaft 221, thereby improving the pumping efficiency of the impeller 10. Moreover, the two stators 23 are axially spaced, and the flywheel 222 is driven to rotate by adopting an axial magnetic flux direct driving mode, so that the output power of the driving unit 20 can be increased on the basis of not increasing the overall radial size of the driving unit 20.

The structure of the drive unit 20 will be specifically described below.

Referring to fig. 12, the driving unit 20 includes a housing 21, and a rotor 22, a first stator 23a, a second stator 23b, a distal bearing 24, a proximal bearing 25 and a control member 26 respectively installed in the housing 21.

Specifically, each stator 23 includes a plurality of posts 231 arranged around the axis of the rotating shaft 221, and a coil winding 232 wound around the outer periphery of each post 231. As shown in fig. 13, the post 231 includes a rod portion 2311, and a first head portion 2312a and a second head portion 2312b respectively disposed at both ends of the rod portion 2311.

The axial distance between the post 231 of the first stator 23a and the first magnet 223a or/and the second magnet 223b is 0.1mm to 2mm, preferably 0.1mm to 0.5 mm. The axial distance between the post 231 of the second stator 23b and the third magnet 223c or/and the fourth magnet 223d is 0.1mm to 2mm, preferably 0.1mm to 0.5 mm.

Since each stator 23 of the second embodiment has the same structure as that of the stator of the first embodiment, the detailed structure of the stator 23 will not be described herein.

Referring to fig. 14, the housing 21 includes a first housing 211, a second housing 212, two third housings 213 and a fourth housing 214.

The first housing 211 is disposed outside the distal end of the rotor 22, the second housing 212 is disposed outside the proximal end of the rotor 22, the two third housings 213 are disposed outside the two stators, and the fourth housing 214 is located between the two third housings 213 and disposed outside the second flywheel 222 b. Since the structures of the first housing 211, the second housing 212, and the third housing 213 of the second embodiment are the same as those of the first embodiment, the detailed structures of the first housing 211, the second housing 212, and the third housing 213 are not repeated herein.

The fourth housing 214 is substantially a structure with two open ends, and is disposed outside the flywheel 222. The two ends of the fourth shell 214 are respectively provided with a connecting piece matched with the third shell 213, so that the fourth shell 214 is fixedly connected with the third shells 213 positioned at the two sides thereof.

The inner wall of the fourth housing 214 is provided with a positioning structure 2141, and the connecting wires of the coil winding 232 are fixed in the positioning structure 2141. By fixing the connecting wires of the coil windings 232 on the positioning structure 2141, the connecting wires of the coil windings 232 can be kept away from the flywheel 222, and the connecting wires are prevented from moving randomly, so that the connecting wires are prevented from being damaged when the flywheel 222 rotates at a high speed.

In the embodiment shown in fig. 14, the positioning structure 2141 is an axially extending slot structure in which the connecting wires of the coil windings 232 are held to prevent the connecting wires from being randomly displaced. It is understood that the present embodiment does not limit the specific structure of the positioning structure 2141, as long as it can prevent the connecting wires of the coil winding 232 from being damaged by the flywheel 222. For example, in other embodiments, the positioning structure 2141 is two hole structures spaced apart from each other, and the connection wires of the coil winding 232 extend through one of the hole structures to the outside of the fourth housing 214, and then extend through the other hole structure to the inside of the fourth housing 214 after passing over the flywheel 222.

It should be understood that the housing 21 of the present embodiment is only used as an example, and is not limited to the present application, and the housing 21 of the present application may also have other structures as long as it can be sleeved outside the stator 23 and the rotor 22 to play a role in sealing the stator 23 and the rotor 22. For example, in other embodiments, the housing 21 includes a first housing 211 that fits over the distal end of the rotor 22, a second housing 212 that fits over the proximal end of the rotor 22, and a fifth housing that fits over both the stator and the flywheel.

It is understood that the present invention is not limited to the above embodiments, and various modifications and changes can be made without departing from the spirit and scope of the present invention.

It is clear to those skilled in the art that, for convenience and brevity of description, the specific working processes of the above-described systems, apparatuses and units may refer to the corresponding processes in the foregoing method embodiments, and are not described herein again.

The above description is only for the specific embodiments of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art can easily conceive of the changes or substitutions within the technical scope of the present invention, and all the changes or substitutions should be covered within the scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.

Claims

1. A blood pump comprising a cannula having a blood flow inlet and a blood flow outlet, an impeller disposed within the cannula, and a drive unit to rotate the impeller; the drive unit comprises a shell, and a rotor and a stator which are arranged in the shell, the proximal end of the sleeve is connected to the shell, the rotor comprises a rotating shaft, and the rotating shaft extends out of the shell and is connected with the impeller; the rotor is characterized by further comprising at least two magnets which are arranged on the rotating shaft at intervals along the axial direction, the stator is arranged around the rotating shaft and located between the two magnets, and a rotating magnetic field generated by the stator interacts with the two magnets respectively to enable the rotating shaft to rotate.

2. The blood pump of claim 1, wherein said stator comprises a plurality of posts disposed about the axis of said shaft, and a coil winding disposed about the periphery of each of said posts, said posts comprising a shaft portion, and first and second head portions disposed at opposite ends of said shaft portion;

3. The blood pump of claim 2, wherein the axial spacing of said first magnet from said post is between 0.1mm and 2 mm; and/or the axial distance between the second magnet and the column is 0.1-2 mm.

4. The blood pump of claim 2, wherein said rotor further comprises at least two flywheels disposed on said shaft, and wherein said two magnets are respectively secured to respective ones of said flywheels.

5. The blood pump of claim 4, wherein said flywheel is a disk-like structure, said magnet being mounted on a side of said flywheel facing said stator.

6. The blood pump of claim 4, wherein a positioning structure is provided at a position of said housing close to said flywheel, and connection wires of said coil windings are fixed in said positioning structure.

7. The blood pump according to claim 1, wherein said rotor comprises three flywheels axially spaced apart and disposed on said shaft, a first flywheel, a second flywheel and a third flywheel, respectively, said first flywheel having a first magnet mounted thereon, said second flywheel having a second magnet and a third magnet mounted thereon, respectively, and said third flywheel having a fourth magnet mounted thereon;

8. The blood pump of claim 1, wherein said housing comprises a first housing disposed over a distal end of said rotor, a second housing disposed over a proximal end of said rotor, and a third housing disposed over said stator;

9. The blood pump of claim 8, wherein said drive unit further comprises a distal bearing and a proximal bearing respectively connected to said shaft, and a control electrically connected to the coil windings of said stator;

10. The blood pump of claim 1, wherein said magnet is comprised of a plurality of magnetic units disposed about the axis of said shaft, adjacent ones of said magnetic units being spaced apart.