Magnetic control position suspension centrifugal blood pump

Abstract

The utility model discloses a magnetic control position suspension centrifugal blood pump which comprises a pump shell, a rotor and an impeller, the pump shell is provided with a pump cavity and a pump pipe vertically connected to the top of the pump cavity, the impeller is contained in the pump cavity, and the rotor is inserted into the pump pipe in the vertical direction and fixedly connected to the top of the impeller; a first permanent magnet suspension bearing and a second permanent magnet suspension bearing are arranged between the upper end and the lower end of the rotor and the pump pipe correspondingly and both used for applying radial acting force to the rotor. A third permanent magnet suspension bearing and a fourth permanent magnet suspension bearing are arranged between the upper end and the lower end of the impeller and the pump cavity correspondingly and both used for applying axial acting force to the impeller. The suspension effect of the blood pump can be greatly improved, a complex structure and a control system are not needed, stable suspension can be achieved in an axial extremely short distance interval, and miniaturization and light weight of the blood pump can be achieved.

Description

Technical Field

[0001] The utility model relates to the technical field of implantable medical devices, and particularly relates to a magnetically controlled position suspension centrifugal blood pump. Background Art

[0002] A centrifugal blood pump is an artificial heart assist circulation device, which generally consists of components such as a pump body, a motor, an impeller, and a bearing. The pump body is the outer shell of the blood pump. The motor usually consists of a rotor and a stator winding, which is used to drive the impeller to rotate and do work. The bearing is used to support the rotor. When the motor of the blood pump drives the rotor to drive the impeller to rotate, blood is sucked into the interior of the pump body and is pushed towards the outlet of the pump body under the action of the centrifugal force of the impeller, realizing blood circulation.

[0003] Because there is no physical contact during the operation of the magnetic suspension blood pump, the rotor will not generate wear, foreign objects, and heat during rotation, nor will it have a squeezing effect on the blood, so it can greatly reduce the damage to the blood and reduce complications. Therefore, the magnetic suspension blood pump is the mainstream direction of current blood pump research and development.

[0004] At present, the suspension bearings used in existing magnetic suspension blood pumps can be roughly divided into hydrodynamic liquid suspension bearings and electromagnetic permanent magnet hybrid magnetic suspension bearings. The hydrodynamic liquid suspension bearings not only have a small suspension force, but also have poor restrictions on the radial displacement and deflection freedom of the rotor impeller, and the suspension effect is not good. The electromagnetic permanent magnet hybrid magnetic suspension bearing contains a magnetic bearing that can be actively controlled. Although its stiffness is controllable and the suspension stability is good, its system and structure are complex, and its volume and weight are large, which is not conducive to human implantation. Therefore, it is necessary to improve the existing technology to overcome the defects in the existing technology. Content of the Utility Model

[0005] In order to solve the above technical problems, the utility model provides a magnetically controlled position suspension centrifugal blood pump, which adopts four groups of permanent magnet suspension bearings, can effectively and reliably control the axial displacement freedom and the radial displacement and deflection freedom of the rotor and the impeller, improves the suspension stability, and has a small volume and a light weight.

[0006] The technical solution adopted by the present utility model to solve its technical problems is as follows: A magnetically controlled position-suspended centrifugal blood pump, comprising: a pump housing, a rotor, and an impeller. The pump housing is provided with a pump chamber and a pump pipe vertically connected to the top of the pump chamber. The impeller is accommodated in the pump chamber, and the rotor is inserted into the pump pipe in the vertical direction and fixedly connected to the top of the impeller. A first permanent magnet suspension bearing and a second permanent magnet suspension bearing are respectively arranged between the upper and lower ends of the rotor and the pump pipe. Both the first permanent magnet suspension bearing and the second permanent magnet suspension bearing are used to apply radial acting forces to the rotor. A third permanent magnet suspension bearing and a fourth permanent magnet suspension bearing are respectively arranged between the upper and lower ends of the impeller and the pump chamber. Both the third permanent magnet suspension bearing and the fourth permanent magnet suspension bearing are used to apply axial acting forces to the impeller.

[0007] As a further improvement of the present utility model, both the first permanent magnet suspension bearing and the second permanent magnet suspension bearing include an outer magnetic sheet and an inner magnetic sheet. The outer magnetic sheet is fixedly arranged in the pump pipe, and the inner magnetic sheet is fixedly arranged in the rotor. Both the outer magnetic sheet and the inner magnetic sheet are magnetized along the axial direction and there is a radial acting force between them.

[0008] As a further improvement of the present utility model, the outer magnetic sheet and the inner magnetic sheet are offset in the axial direction, so that there is also an axial acting force between them. When at rest, the resultant axial acting force applied by the first permanent magnet suspension bearing and the second permanent magnet suspension bearing to the rotor and the axial acting force applied by the third permanent magnet suspension bearing and the fourth permanent magnet suspension bearing to the impeller act axially downward.

[0009] As a further improvement of the present utility model, both the third permanent magnet suspension bearing and the fourth permanent magnet suspension bearing include a first magnetic sheet and a second magnetic sheet. The first magnetic sheet and the second magnetic sheet are respectively fixedly arranged on the impeller and the pump chamber and are distributed oppositely up and down. Both the first magnetic sheet and the second magnetic sheet are magnetized along the axial direction and there is an axial acting force between them.

[0010] As a further improvement of the present utility model, the rotor is a tubular shape with a hollow interior and open ends at both ends. Thus, a first liquid inlet flow channel is formed by its internal cavity, and a second liquid inlet flow channel is formed by the gap between the rotor and the pump pipe. Both the first liquid inlet flow channel and the second liquid inlet flow channel lead to the interior of the impeller.

[0011] As a further improvement of the present utility model, the impeller includes an upper cover plate, a lower cover plate, and a plurality of blades fixedly arranged between the upper cover plate and the lower cover plate and distributed in a circular array. Both the upper cover plate and the lower cover plate are circular, and the inner hole diameter of the upper cover plate is larger than the inner hole diameter of the lower cover plate. The cross-sections of the plurality of blades are all spiral-shaped.

[0012] As a further improvement of the present utility model, a central cone is provided in the inner hole of the lower cover plate. A ceramic ball is installed at the bottom of the central cone, and a ceramic block is provided on the inner bottom wall of the pump chamber. The ceramic ball is supported on the ceramic block.

[0013] As a further improvement of the present utility model, the cross-section of the inner peripheral wall of the pump chamber is spiral-shaped, and the impeller is eccentrically arranged in the pump chamber so that the gap between the outer periphery of the impeller and the inner peripheral wall of the pump chamber gradually increases along the rotation direction of the impeller, thereby forming a spiral-shaped water pressure chamber between the outer periphery of the impeller and the inner peripheral wall of the pump chamber.

[0014] As a further improvement of the present utility model, the pump housing is further provided with a pump outlet pipe connected to the pump chamber, and the larger end of the water pressure chamber leads to the pump outlet pipe.

[0015] As a further improvement of the present utility model, a conical diffusion channel is provided in the pump outlet pipe, and the inner diameter of the diffusion channel gradually increases from the end connected to the water pressure chamber to the other end.

[0016] The beneficial effects of the present utility model are as follows:

[0017] 1. The present utility model provides a magnetically controlled position suspension centrifugal blood pump, which uses four groups of permanent magnet suspension bearings to control the degrees of freedom in multiple directions of the radial displacement, radial deflection and axial displacement of the rotor and the impeller. The remaining axial rotation degree of freedom is the working degree of freedom. This method can greatly improve the suspension effect, without complex structures and control systems, has good suspension control stability, is easy to achieve relatively stable suspension in a very short axial distance interval, and is beneficial to the miniaturization and light weight of the blood pump.

[0018] 2. By providing a first liquid inlet flow channel in the rotor, the present utility model can reduce the gap between the rotor and the pump tube without reducing the cross-sectional area of the liquid inlet flow channel, thereby reducing the air gap between the stator winding and the rotor magnet of the motor and improving the motor efficiency.

[0019] 3. The pump chamber in the present utility model has a spiral structure. By eccentrically arranging the impeller in the pump chamber, the gap between the outer periphery of the impeller and the inner peripheral wall of the pump chamber gradually increases along the rotation direction of the impeller, thereby forming a spiral-shaped water pressure chamber between the outer periphery of the impeller and the inner peripheral wall of the pump chamber. When the impeller rotates, the blood is pushed into the water pressure chamber between the outer periphery of the impeller and the inner peripheral wall of the pump chamber. Since the water pressure chamber has a spiral structure, the flow rate of the blood will be reduced, and the kinetic energy will be converted into pressure energy, thereby increasing the output pressure and improving the energy efficiency of the blood pump. Description of the Drawings

[0020] Figure 1 is a three-dimensional view of the magnetically controlled position suspension centrifugal blood pump of the present utility model;

[0021] Figure 2 This is a longitudinal sectional view of the magnetically controlled position suspension centrifugal blood pump of the present utility model;

[0022] Figure 3 For the present utility model Figure 2 An enlarged view of part A in it;

[0023] Figure 4 For the present utility model Figure 2 An enlarged view of part B in it;

[0024] Figure 5 This is an exploded view of the magnetically controlled position suspension centrifugal blood pump of the present utility model;

[0025] Figure 6 This is a transverse sectional view of the magnetically controlled position suspension centrifugal blood pump of the present utility model;

[0026] Figure 7 This is a three-dimensional view of the rotor and impeller of the magnetically controlled position suspension centrifugal blood pump of the present utility model;

[0027] Figure 8 This is a three-dimensional view of the rotor and impeller of the magnetically controlled position suspension centrifugal blood pump of the present utility model from another perspective;

[0028] Figure 9 This is a longitudinal sectional view of the rotor and impeller of the magnetically controlled position suspension centrifugal blood pump of the present utility model.

[0029] In conjunction with the attached drawings, the following description is made:

[0030] 1. Pump housing; 11. Pump chamber; 111. Ceramic block; 112. Water pressing chamber; 12. Pump pipe; 120. Second liquid inlet flow channel; 121. Outer pipe; 122. Inner pipe; 13. Pump outlet pipe; 131. Diffusion channel; 14. Pump cover; 2. Rotor; 201. First liquid inlet flow channel; 3. Impeller; 31. Upper cover plate; 32. Lower cover plate; 321. Central cone; 322. Ceramic ball; 33. Blade; 4. First permanent magnet suspension bearing; 5. Second permanent magnet suspension bearing; 451. Outer magnetic sheet; 452. Inner magnetic sheet; 6. Third permanent magnet suspension bearing; 7. Fourth permanent magnet suspension bearing; 671. First magnetic sheet; 672. Second magnetic sheet; 8. Stator winding; 9. Rotor magnet. Specific embodiments

[0031] The following is a detailed description of the preferred embodiments of the present utility model in conjunction with the attached drawings.

[0032] Referring to Figures 1 to 9 , the present utility model provides a magnetically controlled position suspension centrifugal blood pump, including: pump housing 1, rotor 2, impeller 3, stator winding 8 and rotor magnet 9.

[0033] Among them, the pump housing 1 is provided with a pump chamber 11, a pump pipe 12, a pump outlet pipe 13 and a pump cover 14. The pump pipe 12 is vertically connected to the top of the pump chamber 11; the pump outlet pipe 13 is in the same plane as the pump chamber 11 and is connected to one side of the pump chamber 11; the pump cover 14 covers the top of the pump chamber 11.

[0034] In this embodiment, the pump pipe 12 is composed of an outer pipe 121 and an inner pipe 122. The inner pipe 122 is integrally arranged at the top of the pump chamber 11, the outer pipe 121 is sleeved outside the inner pipe 122, and a receiving cavity is left between the two.

[0035] Furthermore, the impeller 3 is accommodated in the pump chamber 11. The rotor 2 is inserted vertically into the pump pipe 12 and fixedly connected to the top of the impeller 3, and the axis of the rotor 2 coincides with the axis of the impeller 3. The stator winding 8 is fixedly installed in the receiving cavity between the outer pipe 121 and the inner pipe 122, the rotor permanent magnet 9 is fixedly installed in the rotor 2, and the rotor permanent magnet 9 is located in the middle of the stator winding 8. Thus, the columnar motor is jointly composed of the rotor 2, the stator winding 8 and the rotor permanent magnet 9. Using this columnar motor can facilitate the radial suspension and stable control of the rotor 2 and the impeller 3.

[0036] Exemplarily, the columnar motor is a DC brushless motor, and sinusoidal wave control can be adopted. The current change is relatively smooth to reduce the vibration and noise of the motor.

[0037] In the present utility model, the rotor 2 of the columnar motor is integrated with the impeller 3. Driven by the columnar motor, the rotating rotor 2 drives the impeller 3 to rotate. Under the centrifugal force of the impeller 3, the blood is pushed to flow.

[0038] Refer to Figure 2 , a first permanent magnet suspension bearing 4 is arranged between the upper end of the rotor 2 and the pump pipe 12, and a second permanent magnet suspension bearing 5 is arranged between the lower end of the rotor 2 and the pump pipe 12. Both the first permanent magnet suspension bearing 4 and the second permanent magnet suspension bearing 5 are used to apply radial forces to the rotor 2 to constrain the radial displacement freedom degree of the rotor 2; at the same time, this up-and-down distribution method of the first permanent magnet suspension bearing 4 and the second permanent magnet suspension bearing 5 can also constrain the radial deflection freedom degree of the rotor 2 to prevent the rotor 2 from tilting. The present utility model uses two sets of permanent magnet suspension bearings (i.e., the first permanent magnet suspension bearing 4 and the second permanent magnet suspension bearing 5) up and down to provide radial displacement freedom degree and radial deflection freedom degree support for the rotating body (i.e., the rotor 2 and the impeller 3), so that the rotating body can maintain radial centering and improve stability.

[0039] It can be understood that "a first permanent magnet suspension bearing 4 is arranged between the upper end of the rotor 2 and the pump pipe 12" does not mean that "the first permanent magnet suspension bearing 4 is arranged in the gap between the upper end of the rotor 2 and the pump pipe 12", but means that "a part of the first permanent magnet suspension bearing 4 is installed at the upper end of the rotor 2 and another part is installed in the pump pipe 12". The same applies to the following text.

[0040] In addition, the first permanent magnet magnetic suspension bearing 4 and the second permanent magnet magnetic suspension bearing 5 can also apply axial acting forces to the rotor 2 simultaneously.

[0041] Furthermore, a third permanent magnet magnetic suspension bearing 6 is arranged between the upper end of the impeller 3 and the pump chamber 11, and a fourth permanent magnet magnetic suspension bearing 7 is arranged between the lower end of the impeller 3 and the pump chamber 11. Both the third permanent magnet magnetic suspension bearing 6 and the fourth permanent magnet magnetic suspension bearing 7 are used to apply axial acting forces to the impeller 3 to ensure stable axial suspension when the rotor 2 and the impeller 3 rotate.

[0042] When at rest, the axial acting forces applied by the first permanent magnet magnetic suspension bearing 4 and the second permanent magnet magnetic suspension bearing 5, plus the axial acting forces applied by the third permanent magnet magnetic suspension bearing 6 and the fourth permanent magnet magnetic suspension bearing 7, result in a downward axial resultant force on the rotor 2 and the impeller 3, enabling the rotor 2 and the impeller 3 to be supported on the inner bottom wall of the pump chamber 11 for smooth startup during operation.

[0043] It can be seen that the present utility model uses four groups of permanent magnet magnetic suspension bearings to control the degrees of freedom in multiple directions of the radial displacement, radial deflection, and axial displacement of the rotor 2 and the impeller 3. The remaining axial rotation degree of freedom is the working degree of freedom. This method can greatly improve the suspension effect, without the need for complex structures and control systems, has good suspension control stability, is easy to achieve relatively stable suspension within a very short axial distance range, and is conducive to the miniaturization and light weight of the blood pump.

[0044] Refer to Figure 3 and Figure 4 Both the first permanent magnet magnetic suspension bearing 4 and the second permanent magnet magnetic suspension bearing 5 include an outer magnetic sheet 451 and an inner magnetic sheet 452. The outer magnetic sheet 451 and the inner magnetic sheet 452 are both annular. The outer magnetic sheet 451 is fixedly arranged in the pump tube 12, and the inner magnetic sheet 452 is fixedly arranged in the rotor 2. Both the outer magnetic sheet 451 and the inner magnetic sheet 452 are magnetized axially and there is a radial acting force between them. Among them, the number, thickness, and magnetic pole direction of the outer magnetic sheet 451 and the inner magnetic sheet 452 are not limited and can be configured accordingly according to requirements.

[0045] Exemplarily, the outer magnetic sheet 451 of the first permanent magnet magnetic suspension bearing 4 is provided with four. The four outer magnetic sheets 451 are axially stacked and distributed. The magnetic pole directions of the first and third ones from top to bottom are the same, with the upper end being the S pole and the lower end being the N pole; the magnetic pole directions of the second and fourth ones from top to bottom are the same, with the upper end being the N pole and the lower end being the S pole. The inner magnetic sheet 452 of the first permanent magnet magnetic suspension bearing 4 is the same as its outer magnetic sheet 451, and the second permanent magnet magnetic suspension bearing 5 is the same as the first permanent magnet magnetic suspension bearing 4. Specifically, refer to Figure 3 and Figure 4 Here, no more details will be elaborated.

[0046] In addition, the outer magnetic disc 451 and the inner magnetic disc 452 are axially offset, so that there is also an axial force between them, and then an axial force is applied to the rotor 2. In this embodiment, the inner magnetic disc 452 of the first permanent magnetic suspension bearing 4 is distributed above its outer magnetic disc 451 (as Figure 3 shown), and the inner magnetic disc 452 of the second permanent magnetic suspension bearing 5 is distributed below its outer magnetic disc 451 (as Figure 4 shown). However, the resultant axial force applied by the first permanent magnetic suspension bearing 4 and the second permanent magnetic suspension bearing 5 to the rotor 2 is downward axially. The magnitude of this resultant force is determined by the liquid suspension force generated when the impeller 3 rotates. When the blood pump is working, this resultant force, the liquid suspension force, and the axial forces applied by the third permanent magnetic suspension bearing 6 and the fourth permanent magnetic suspension bearing 7 reach equilibrium.

[0047] Furthermore, both the third permanent magnetic suspension bearing 6 and the fourth permanent magnetic suspension bearing 7 include a first magnetic disc 671 and a second magnetic disc 672. The first magnetic disc 671 and the second magnetic disc 672 are respectively fixed to the impeller 3 and the pump chamber 11 and are distributed opposite to each other vertically; both the first magnetic disc 671 and the second magnetic disc 672 are magnetized axially and there is an axial force between them.

[0048] Among them, the impeller 3 includes an upper cover plate 31, a lower cover plate 32, and a plurality of blades 33 fixed between the upper cover plate 31 and the lower cover plate 32 and distributed in a circular array.

[0049] As Figure 4 shown, the first magnetic disc 671 of the third permanent magnetic suspension bearing 6 is fixed in the upper cover plate 31, and the second magnetic disc 672 of the third permanent magnetic suspension bearing 6 is fixed in the upper wall of the pump chamber 11; there are no restrictions on the number, thickness, and magnetic pole directions of the first magnetic disc 671 and the second magnetic disc 672. In this embodiment, one first magnetic disc 671 and one second magnetic disc 672 are provided for the third permanent magnetic suspension bearing 6. The magnetic poles at the ends facing each other of the two are the same, so that there is an axial repulsive force between them; exemplarily, the magnetic poles at the upper and lower ends of the first magnetic disc 671 of the third permanent magnetic suspension bearing 6 are S and N respectively; the magnetic poles at the upper and lower ends of the second magnetic disc 672 of the third permanent magnetic suspension bearing 6 are N and S respectively.

[0050] The first magnetic piece 671 of the fourth permanent magnet suspension bearing 7 is fixedly arranged in the lower cover plate 32, and the second magnetic piece 672 of the fourth permanent magnet suspension bearing 7 is fixedly arranged in the lower wall of the pump chamber 11; there are no restrictions on the number, thickness and magnetic pole direction of the first magnetic piece 671 and the second magnetic piece 672. In this embodiment, two first magnetic pieces 671 and two second magnetic pieces 672 of the third permanent magnet suspension bearing 6 are each provided, and both are annular. The two first magnetic pieces 671 are distributed inside and outside, and similarly the two second magnetic pieces 672 are also distributed inside and outside; the ends of the first magnetic piece 671 and the second magnetic piece 672 facing each other have the same magnetic pole, so that there is an axial repulsive force between the two. Exemplarily, in the fourth permanent magnet suspension bearing 7, the upper and lower magnetic poles of the outer first magnetic piece 671 are S and N respectively; the upper and lower magnetic poles of the inner first magnetic piece 671 are N and S respectively; the upper and lower magnetic poles of the outer second magnetic piece 672 are N and S respectively; the upper and lower magnetic poles of the inner second magnetic piece 672 are S and N respectively. In this embodiment, the fourth permanent magnet suspension bearing 7 can not only provide an axial repulsive force for the impeller 3 in this way, but also restrict the radial displacement freedom of the impeller 3 by relying on the acting force between the inner and outer magnetic pieces.

[0051] Refer to Figure 2 and Figure 3 , the rotor 2 is a tubular shape with a hollow interior and open ends at both ends, and thus a first liquid inlet flow channel 201 is formed by its internal cavity. The gap between the rotor 2 and the pump pipe 12 forms a second liquid inlet flow channel 120. Both the first liquid inlet flow channel 201 and the second liquid inlet flow channel 120 lead to the inside of the impeller 3. Since the first liquid inlet flow channel 201 is provided in the rotor 2 in the present utility model, without reducing the cross-sectional area of the liquid inlet flow channel, the gap between the rotor 2 and the pump pipe 12 can be reduced, thereby reducing the air gap between the stator winding 8 and the rotor magnet 9 of the motor and improving the motor efficiency.

[0052] Refer to Figure 7 , both the upper cover plate 31 and the lower cover plate 32 are circular rings, and the inner hole diameter of the upper cover plate 31 is larger than the inner hole diameter of the lower cover plate 32. The inner hole of the upper cover plate 31 is for blood to enter between the blades 33 from the first liquid inlet flow channel 201 and the second liquid inlet flow channel 120, and the inner hole of the lower cover plate 32 is for the blood between the lower cover plate 32 and the inner bottom wall of the pump chamber 11 to return to between the blades 33. The present utility model adopts the impeller 3 with this closed structure, so that the impeller 3 can generate axial hydraulic power when rotating, enabling the impeller 3 to axially suspend.

[0053] In this embodiment, each blade 33 extends in the vertical direction, and its cross-section is in a spiral shape, more precisely, it is taken from a certain section of the spiral. The blades 33 with this shape can more effectively throw out the blood when rotating.

[0054] Refer to Figure 8 and Figure 9, a central cone 321 is provided in the inner hole of the lower cover plate 32. The central cone 321 is fixed in the inner hole of the lower cover plate 32 by several connecting ribs. The top of the central cone 321 is in a sharp cone shape, which is located in the middle of the impeller 3 and is opposite to the first liquid inlet flow channel 201, used to reduce the liquid inlet resistance and guide the blood to flow towards the blade 33. A ceramic ball 322 is installed at the bottom of the central cone 321. The ceramic ball 322 protrudes downward from the bottom surface of the lower cover plate 32, and a ceramic block 111 is provided on the inner bottom wall of the pump chamber 11; when at rest, the ceramic ball 322 is supported on the ceramic block 111.

[0055] It is worth mentioning that, as Figure 6 shown, the pump chamber 11 of the present utility model is not circular, but a spiral structure. Specifically, the cross-section of the inner peripheral wall of the pump chamber 11 is spiral-shaped. The impeller 3 is eccentrically arranged in the pump chamber 11 so that the gap between the outer periphery of the impeller 3 and the inner peripheral wall of the pump chamber 11 gradually increases along the rotation direction of the impeller 3, thereby forming a spiral water pressure chamber 112 between the outer periphery of the impeller 3 and the inner peripheral wall of the pump chamber 11. The end with a larger size of the water pressure chamber 112 leads to the pump outlet pipe 13.

[0056] When the impeller 3 rotates, the blood enters the pump chamber 11 through the first liquid inlet flow channel 201 and the second liquid inlet flow channel 120 and generates kinetic energy under the action of the impeller 3. The impeller 3 pushes the blood into the water pressure chamber 112 between the outer periphery of the impeller 3 and the inner peripheral wall of the pump chamber 11. Since the water pressure chamber 112 is a spiral structure and its size gradually increases along the rotation direction of the impeller 3, when the impeller 3 drives the fluid to flow along the spiral direction of the water pressure chamber 112, the flow rate of the fluid will be reduced, converting the kinetic energy into pressure energy, thereby increasing the output pressure and improving the energy efficiency of the blood pump.

[0057] In addition, a conical diffusion channel 131 is provided in the pump outlet pipe 13, and the inner diameter of the diffusion channel 131 gradually increases from the end connected to the water pressure chamber 112 towards the other end. Similarly, by setting the conical diffusion channel 131, when the blood flows outwards along the diffusion channel 131, the flow rate of the blood can be further reduced, converting the kinetic energy into pressure energy, and further increasing the output pressure to pressurize and push the blood flowing through the blood pump into the output pipeline connected to the pump outlet pipe 13.

[0058] When at rest, the radial repulsive forces generated by the first permanent magnetic suspension bearing 4 and the second permanent magnetic suspension bearing 5 make the rotor 2 and the impeller 3 radially balanced and stable; the axially downward pressure generated by the bias of the first permanent magnetic suspension bearing 4 and the second permanent magnetic suspension bearing 5, plus the axially downward repulsive force generated by the third permanent magnetic suspension bearing 6, is greater than the axially upward repulsive force generated by the fourth permanent magnetic suspension bearing 7, making the ceramic ball 322 supported on the ceramic block 111. At this time, the distance between the fourth permanent magnetic suspension bearings 7 is the closest and the repulsive force is the largest; the distance between the third permanent magnetic suspension bearings 6 is the farthest and the repulsive force is the smallest.

[0059] After the blood pump is started, the radial repulsive forces generated by the first permanent magnetic suspension bearing 4 and the second permanent magnetic suspension bearing 5 keep the rotor 2 and the impeller 3 radially balanced and stable; the suspension force generated by the rotation of the impeller 3 increases with the increase of the rotational speed until the liquid suspension force and the resultant force of each axial acting force are zero and the impeller is suspended. After the rotor 2 and the impeller 3 float upward, the axial pressure generated by the offset of the first permanent magnetic suspension bearing 4 and the second permanent magnetic suspension bearing 5 becomes smaller; the distance between the fourth permanent magnetic suspension bearings 7 becomes larger and the repulsive force becomes smaller, that is, the upward buoyancy becomes smaller; the distance between the third permanent magnetic suspension bearings 6 becomes smaller and the repulsive force becomes larger, that is, the pressure becomes larger, pressing the impeller 3 to the equilibrium position, so that relatively stable suspension can be achieved within a very short axial distance range.

[0060] It can be seen from this that the magnetically controlled position suspension centrifugal blood pump of the present invention uses four groups of permanent magnetic suspension bearings to achieve multiple degrees of freedom in controlling the radial displacement, radial deflection and axial displacement of the rotor 2 and the impeller 3. The remaining axial rotation degree of freedom is the working degree of freedom. This method can greatly improve the suspension effect, without complex structures and control systems, has good suspension control stability, is easy to achieve relatively stable suspension within a very short axial distance range, and is conducive to the miniaturization and light weight of the blood pump. At the same time, the present invention is provided with a first liquid inlet channel 201 in the rotor 2. Without reducing the cross-sectional area of the liquid inlet channel, the gap between the rotor 2 and the pump tube 12 can be reduced, thereby reducing the air gap between the stator winding 8 and the rotor magnet 9 of the motor and improving the motor efficiency. In addition, the pump chamber 11 in the present invention is of a spiral structure. By eccentrically arranging the impeller 3 in the pump chamber 11, the gap between the outer periphery of the impeller 3 and the inner peripheral wall of the pump chamber 11 gradually increases along the rotation direction of the impeller 3, so as to form a spiral water pressure chamber 112 between the outer periphery of the impeller 3 and the inner peripheral wall of the pump chamber 11. When the impeller 3 rotates, the blood is pushed into the water pressure chamber 112 between the outer periphery of the impeller 3 and the inner peripheral wall of the pump chamber 11. Since the water pressure chamber 112 is of a spiral structure, the flow rate of the blood will be reduced, converting kinetic energy into pressure energy, thereby increasing the output pressure and improving the energy efficiency of the blood pump.

[0061] Many specific details have been set forth 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, and the present invention can be implemented in many other ways different from those described herein. Therefore, the present invention is not limited by the specific embodiments disclosed above. At the same time, any person skilled in the art can make many possible changes and modifications to the technical solution of the present invention by 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 with equivalent changes. All simple modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention still fall within the scope of the protection of the technical solution of the present invention.

Claims

1. A magnetically controlled position suspension centrifugal blood pump, comprising a pump housing (1), a rotor (2) and an impeller (3), wherein the pump housing (1) is provided with a pump chamber (11) and a pump tube (12) vertically connected to the top of the pump chamber (11), the impeller (3) is accommodated in the pump chamber (11), and the rotor (2) is vertically inserted into the pump tube (12) and fixedly connected to the top of the impeller (3); characterized in that: A first permanent magnetic suspension bearing (4) and a second permanent magnetic suspension bearing (5) are respectively arranged between the upper and lower ends of the rotor (2) and the pump pipe (12), and the first permanent magnetic suspension bearing (4) and the second permanent magnetic suspension bearing (5) are both used to apply a radial force to the rotor (2); a third permanent magnetic suspension bearing (6) and a fourth permanent magnetic suspension bearing (7) are respectively arranged between the upper and lower ends of the impeller (3) and the pump chamber (11), and the third permanent magnetic suspension bearing (6) and the fourth permanent magnetic suspension bearing (7) are both used to apply an axial force to the impeller (3).

2. The magnetically controlled position suspension centrifugal blood pump according to claim 1, characterized in that: The first permanent magnetic suspension bearing (4) and the second permanent magnetic suspension bearing (5) both comprise an outer magnetic sheet (451) and an inner magnetic sheet (452); the outer magnetic sheet (451) is fixedly disposed in the pump pipe (12); the inner magnetic sheet (452) is fixedly disposed in the rotor (2); the outer magnetic sheet (451) and the inner magnetic sheet (452) are both magnetized along the axial direction and a radial force exists between the two.

3. The magnetically controlled position suspension centrifugal blood pump according to claim 2, characterized in that: The outer magnetic sheet (451) and the inner magnetic sheet (452) are distributed in an offset manner in the axial direction so that an axial force exists between the two. When stationary, the combined force of the axial force applied by the first permanent magnetic suspension bearing (4) and the second permanent magnetic suspension bearing (5) to the rotor (2) and the axial force applied by the third permanent magnetic suspension bearing (6) and the fourth permanent magnetic suspension bearing (7) to the impeller (3) is axially downward.

4. The magnetically controlled position suspension centrifugal blood pump according to claim 1, characterized in that: The third permanent magnetic suspension bearing (6) and the fourth permanent magnetic suspension bearing (7) both comprise a first magnetic sheet (671) and a second magnetic sheet (672); the first magnetic sheet (671) and the second magnetic sheet (672) are respectively fixed to the impeller (3) and the pump chamber (11) and are relatively distributed up and down; the first magnetic sheet (671) and the second magnetic sheet (672) are both magnetized along the axial direction and there is an axial force between the two.

5. The magnetically controlled position suspension centrifugal blood pump according to claim 1, characterized in that: The rotor (2) is in the shape of a tube with a hollow interior and openings at both ends, and the cavity inside the rotor forms a first liquid inlet channel (201), and the gap between the rotor (2) and the pump pipe (12) forms a second liquid inlet channel (120), and both the first liquid inlet channel (201) and the second liquid inlet channel (120) lead to the interior of the impeller (3).

6. The magnetically controlled position suspension centrifugal blood pump according to claim 1, characterized in that: The impeller (3) comprises an upper cover plate (31), a lower cover plate (32), and a plurality of blades (33) fixedly arranged between the upper cover plate (31) and the lower cover plate (32) and distributed in an annular array; the upper cover plate (31) and the lower cover plate (32) are both annular in shape, the inner hole diameter of the upper cover plate (31) is larger than the inner hole diameter of the lower cover plate (32), and the cross sections of the plurality of blades (33) are all in the shape of a spiral line.

7. The magnetically controlled position suspension centrifugal blood pump according to claim 6, characterized in that: A central cone (321) is provided in the inner hole of the lower cover plate (32), a ceramic ball (322) is installed at the bottom of the central cone (321), a ceramic block (111) is provided on the inner bottom wall of the pump chamber (11), and the ceramic ball (322) is supported on the ceramic block (111).

8. The magnetically controlled position suspension centrifugal blood pump according to claim 1, characterized in that: The cross section of the inner peripheral wall of the pump chamber (11) is in the shape of a spiral line. The impeller (3) is eccentrically arranged in the pump chamber (11), so that the gap between the outer periphery of the impeller (3) and the inner peripheral wall of the pump chamber (11) gradually increases along the rotation direction of the impeller (3), thereby forming a spiral water pressure chamber (112) between the outer periphery of the impeller (3) and the inner peripheral wall of the pump chamber (11).

9. The magnetically controlled position suspension centrifugal blood pump according to claim 8, characterized in that: The pump housing (1) is also provided with a pump outlet pipe (13) connected to the pump chamber (11), and the larger end of the water pressure chamber (112) leads to the pump outlet pipe (13).

10. The magnetically controlled position suspension centrifugal blood pump according to claim 9, characterized in that: A conical diffusion channel (131) is provided in the pump outlet pipe (13), and the inner diameter of the diffusion channel (131) gradually increases from one end connected to the water pressure chamber (112) toward the other end.

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