Motor for extracorporeal blood pump and extracorporeal blood pump

Abstract

A motor (2) for an extracorporeal blood pump and an extracorporeal blood pump. The motor (2) is used for being engaged with a pump head (1) of the extracorporeal blood pump. The motor (2) comprises: a motor housing (90) inside which an accommodating chamber is formed; an end cover assembly (80) arranged at an upper end of the motor housing (90), wherein the end cover assembly (80) has an inner surface and an outer surface, the inner surface of the end cover assembly (80) faces the accommodating chamber, and the outer surface of the end cover assembly (80) is used for being engaged with the pump head (1); a driving-control assembly arranged in the accommodating chamber and used for driving an impeller (20) in the pump head (1) to rotate and / or controlling the impeller (20) in the pump head (1) to suspend; a first potting glue (40) filling at least a part of the gap between the driving-control assembly and the motor housing (90); and a second potting glue (30) covering at least a part of the inner surface of the end cover assembly (80); wherein the hardness of the first potting glue (40) after curing is greater than that of the second potting glue (30) after curing, and the heat conductivity coefficient of the first potting glue (40) is higher than that of the second potting glue (30).

Description

Motor for extracorporeal blood pump and extracorporeal blood pump

[0001] This application claims priority to the Chinese patent application filed with the China Patent Office on January 26, 2024, with application number 202410111427.2 and invention name “Motor for extracorporeal blood pump and extracorporeal blood pump”, the entire contents of which are incorporated by reference into this application. Technical Field

[0002] The present disclosure generally relates to the field of medical devices, and more particularly to a motor for an extracorporeal blood pump and the extracorporeal blood pump. Background Art

[0003] Blood pumps are used to assist or replace the heart's pumping function, providing a new treatment option for patients with cardiogenic shock and heart failure who were previously hopeless to treat. Based on implantability and clinical use, blood pumps can be divided into implantable blood pumps and extracorporeal blood pumps. Implantable blood pumps can be implanted into the patient's body to temporarily or long-term maintain human blood circulation. They are mainly used for transplantation replacement therapy for patients with end-stage heart failure. Extracorporeal blood pumps are located outside the patient's body when in use. With the help of instruments such as cannulae, they establish a blood circulation circuit with the human body. They can provide transitional life support and treatment with less trauma.

[0004] Whether implantable or extracorporeal, blood pumps inevitably generate heat during operation. This heat increases with the pump's operating time, speed, and auxiliary flow rate. If heat cannot be dissipated quickly, it can damage the pump's electronic components, causing it to malfunction or even stop functioning. Therefore, heat dissipation in blood pumps is a crucial issue.

[0005] When working, an implantable blood pump is located inside the human body and is surrounded by surrounding human tissue. It cannot dissipate heat by transferring heat to the surrounding human tissue. Otherwise, heat will accumulate in these human tissues and cause unacceptable damage. Therefore, for implantable blood pumps, heat dissipation is usually achieved with the help of blood. The heat generated by the blood pump is transferred to the continuously circulating blood and is quickly carried away by the blood to achieve heat dissipation and cooling.

[0006] However, even if the heat is carried away by the blood, it will inevitably cause the temperature of the blood to rise. When the temperature rise exceeds a certain range, it will still cause damage to the blood.

[0007] For an extracorporeal blood pump, since it is located outside the human body during use, a more preferred heat dissipation method is to dissipate the generated heat into the surrounding environment.

[0008] An extracorporeal blood pump mainly includes a motor and a pump head connected to the motor. The heat generated by the blood pump mainly comes from the motor. Research has found that potting compound can be used to fill the gaps inside the motor so that its internal components are surrounded by the cured potting compound. Potting compound usually has better thermal conductivity than air and can quickly transfer the heat generated by the internal components of the motor to the motor housing, which is further dissipated from the motor housing to the surrounding environment, thereby achieving heat dissipation of the motor. At the same time, due to process requirements, some internal components of the motor are glued during the assembly process. Over time, the glued parts may separate, fall off, and fail. By fully filling the gaps between the internal components of the motor and the housing with potting compound, these internal components are fully surrounded by the cured potting compound, thereby enhancing the structural stability and vibration resistance during subsequent use.

[0009] However, in the prior art, a single type of potting compound is usually used for potting motors. Since the potting compound is isotropic in thermal conductivity, that is, the potting compound conducts the heat generated by the internal components of the motor to the surroundings indiscriminately, the temperature of the pump head connected to the motor will also increase accordingly, thereby causing the temperature of the blood pumped inside to increase, and the risk of blood damage.

[0010] On the other hand, in order to minimize the gap between the pump head and the motor, the end cover assembly is usually designed to be thinner, and the volume of the potting compound will change during the curing process, which will generate stress on the surrounding parts. When the stress transmitted to stress-sensitive components such as the end cover assembly is too large, the end cover assembly will be deformed by the force, resulting in the pump head being unable to be assembled smoothly or the impeller being tilted or the impeller position being not centered relative to the pump head housing after assembly. In severe cases, it may even cause the end cover assembly to loosen or break. Summary of the Invention

[0011] In view of the deficiencies in the prior art, the present invention provides a motor for an extracorporeal blood pump and an extracorporeal blood pump to solve at least one of the above technical problems.

[0012] To achieve the above objectives, the present invention provides the following technical solutions.

[0013] In one aspect, the present invention provides a motor for an extracorporeal blood pump, configured to engage with a pump head of the extracorporeal blood pump, the motor comprising:

[0014] a motor housing, wherein an accommodating chamber is formed inside the motor housing;

[0015] an end cover assembly disposed at the upper end of the motor housing, the end cover assembly having an inner surface and an outer surface, the inner surface of the end cover assembly facing the accommodating chamber, and the outer surface of the end cover assembly being used to engage the pump head;

[0016] a drive control assembly, disposed in the accommodating chamber, for driving the impeller in the pump head to rotate and / or controlling the suspension of the impeller in the pump head;

[0017] a first potting compound filling at least a portion of a gap between the drive control assembly and the motor housing;

[0018] a second potting compound covering at least a portion of the inner surface of the end cap assembly;

[0019] The hardness of the first potting glue after curing is greater than the hardness of the second potting glue after curing, and the thermal conductivity of the first potting glue is higher than the thermal conductivity of the second potting glue.

[0020] In another aspect, the present invention provides an extracorporeal blood pump comprising:

[0021] The motor described above; and

[0022] A pump head is detachably engaged with the motor, and the pump head includes a pump casing and an impeller accommodated in the pump casing; the impeller includes a rotor assembly, and the rotor assembly can drive the impeller to rotate and / or suspend under the control of the drive control assembly.

[0023] The present invention fills at least a portion of the gap between the drive control component and the motor housing with a first potting compound. The first potting compound has good thermal conductivity and can quickly transfer the heat generated by the drive control component during operation to the housing, thereby achieving efficient heat dissipation of the motor.

[0024] In the present invention, at least a portion of the inner surface of the end cover assembly is covered with a second potting compound. The second potting compound has poor thermal conductivity and can inhibit the heat generated when the drive control assembly is working from being transferred to the pump head, thereby avoiding a sharp rise in the blood temperature in the pump head and reducing the risk of blood damage.

[0025] That is to say, the present invention realizes directional heat dissipation of the motor based on the differentiated design of the thermal conductivity of the first potting compound and the second potting compound. The directional heat dissipation allows the heat to be basically directed toward the motor housing and finally dissipated to the external environment with the help of the outer surface of the housing. In this way, while achieving heat dissipation, damage to the blood is avoided.

[0026] The first potting compound of the present invention is relatively hard after curing, and has a good supporting and positioning effect on the drive control component. When the motor is subjected to external vibration or impact, it can ensure that the drive control component covered by the first potting compound inside the motor does not shift, thereby ensuring the stability of the internal structure of the shell.

[0027] The second potting compound of the present invention is relatively soft after curing and can fully deform. Therefore, it can effectively absorb external stress and effectively prevent stress generated elsewhere from being transmitted to the end cap assembly, effectively preventing stress-sensitive components such as the end cap assembly from deformation and damage. Furthermore, the soft second potting compound provides cushioning and vibration resistance, protecting the end cap assembly during the connection process between the pump head and the motor.

[0028] The above-mentioned beneficial effects and other beneficial effects of the present invention will be further reflected in the specific embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] FIG1 is a cross-sectional view of an extracorporeal blood pump.

[0030] Explanation of the accompanying symbols: 1. Pump head; 10. Pump head housing; 11. Volute; 12. Annular housing; 14. Blood inlet; 15. Blood outlet; 16. Pump chamber; 17. Annular accommodating chamber; 171 / 172, Radial secondary flow channel; 173, Axial secondary flow channel; 20. Impeller; 21. Impeller housing; 22. Blades; 23. Rotor assembly; 231, Rotor rotating assembly; 232, Rotor suspension assembly; 2. Motor; 30. Second potting compound; 31. First part; 32. Second part; 33. Third part; 40. First potting compound; 41. Part A; 42. Part B; 50. Suspension drive control assembly; 51. Stator teeth; 511. Horizontal part; 512. Vertical part; 52. Stator yoke; 53. Coil; 54. Stator permanent magnet; 55. Axial power body; 60. Rotary drive control assembly; 61. Motor; 62. Output shaft; 63. Active magnet; 70. Drive control circuit board; 71. First drive control circuit board; 80. End cap assembly; 81. Disk; 811. Upper surface of disk; 812. Lower surface of disk; 82. Recess; 822. Outer periphery of recess; 823. Lower end surface of recess; 83. Protrusion; 90. Motor housing; 91. Heat sink DETAILED DESCRIPTION

[0031] As shown in Figure 1, the extracorporeal blood pump of this embodiment includes a motor 2 and a pump head 1 coupled to the motor 2 for pumping blood. In an optional embodiment, the pump head 1 and the motor 2 are detachably coupled, and the specific detachable coupling method can be implemented using the solutions provided in Publication Nos. CN209187707U, CN209204247U, or CN209204246U.

[0032] The pump head 1 includes a pump head housing 10 and an impeller 20 housed within the pump head housing 10. The impeller 20 can be driven by a motor 2 to rotate and pump blood. In an optional embodiment, the impeller 20 can also be controlled by the motor 2 to be suspended within the pump head housing 10. Specifically, the impeller 20 can be suspended within the pump head housing 10 using the magnetic bearings provided in CN111561519B or CN114748788B.

[0033] Although the following description uses a magnetic levitation blood pump and motor as the main scenario, it should be understood that the solution of this embodiment is also applicable to other types of blood pumps and corresponding motors, such as a hydraulically suspended blood pump and its motor, and a mechanical bearing blood pump and its motor.

[0034] Continuing to refer to Figure 1, the pump head housing 10 is roughly composed of two parts, namely a volute 11 located at the upper part, which is roughly in the shape of a flat cylinder, and a ring housing 12 located at the lower part, which is roughly in the shape of a cylindrical cylinder. A blood inlet 14 is provided at a roughly central position on the upper part of the volute 11, and a blood outlet 15 is provided at the outer periphery of the volute 11 along a roughly tangential direction. The pump head housing 10 forms an internal chamber for accommodating an impeller 20. Specifically, the internal chamber of the pump head housing 10 includes a pump chamber 16 formed by the volute 11 and an annular accommodating chamber 17 formed by the annular shell 12, the annular accommodating chamber 17 is located below the pump chamber 16 and is connected thereto, the impeller 20 includes an impeller housing 21, blades 22 located on the upper part of the impeller housing 21, and a rotor assembly 23 fixed to the inside of the impeller housing 21, wherein the blades 22 are roughly located in the pump chamber 16, and the impeller housing 21 and the rotor assembly 23 therein are roughly located in the annular accommodating chamber 17; further, the rotor assembly 23 includes a rotor rotating assembly 231 and a rotor suspension assembly 232.

[0035] Continuing to refer to Figure 1, the motor 2 includes a motor housing 90, an end cover assembly 80 and a drive control assembly. The interior of the motor housing 90 forms a accommodating chamber, which is used to accommodate the drive control assembly. The end cover assembly 80 is arranged at the upper end of the motor housing 90. The end cover assembly 80 has an inner surface and an outer surface. The inner surface of the end cover assembly faces the accommodating chamber, and the outer surface of the end cover assembly is used to engage the pump head 1. The drive control assembly is used to interact with the rotor assembly 23 of the impeller to achieve stable rotation and suspension of the impeller 20.

[0036] The end cover assembly 80 includes an end cover body and components such as sensors, isolation plates, and circuit boards (not shown). Before installing the end cover assembly 80 on the motor housing 90, the sensors, isolation plates, circuit boards and other components will be pre-assembled to the inner surface of the end cover body to form the end cover assembly 80.

[0037] The end cap assembly 80 has a shape that generally fits the pump head 1. Specifically, the end cap assembly 80 includes a generally circular disk 81, the center of which is recessed downward (i.e., toward the side away from the pump head 1) to form a recessed portion 82. The recessed portion 82 is generally annular. When the end cap assembly 80 is engaged with the pump head 1, the annular shell 12 of the pump head 1 is embedded in the recessed portion 82 of the end cap assembly 80, while the lower surface of the volute 11 of the pump head abuts against the upper surface 811 of the disk of the end cap assembly. Therefore, the accurate position of the end cap assembly 80 after assembly determines the accurate position of the pump head 1 after engagement, and further determines whether the rotor assembly 23 inside the pump head can operate stably according to the preset position. For example, if the end cover assembly 80 deviates radially from the preset position, the pump head 1 will also deviate radially from the preset position, while the rotor assembly 23 still maintains a radially centered setting relative to the drive assembly under the action of the drive assembly. The position of the rotor assembly 23 is not centered relative to the pump head housing, that is, the size of the radial secondary flow channels 171 and 172 between the impeller housing 21 and the annular accommodating chamber 17 deviates from the preset value, thereby affecting the fluid mechanics performance of the blood pump. In severe cases, the impeller housing 21 may even touch the side wall of the annular accommodating chamber 17, causing blood damage or even the impeller 20 to stop rotating. At the same time, the radial clearance between some rotating parts in the drive assembly and the end cover assembly 80 will be affected, and in severe cases, the two may collide with each other, affecting the drive efficiency. For another example, if the end cover assembly 80 deviates axially from the preset position, and the rotor assembly 23 still maintains the original preset axial setting under the action of the drive assembly, the size of the axial secondary flow channel 173 between the impeller housing 21 and the annular accommodating chamber 17 will deviate from the preset value, thereby affecting the fluid mechanics performance of the blood pump. In severe cases, the impeller housing 21 may even touch the bottom wall of the annular accommodating chamber 17, causing blood damage or even the impeller 20 to stop rotating. Similarly, it will also have an adverse effect on the driving efficiency.

[0038] For mechanical bearing blood pumps, inaccurate positioning of the end cap assembly 80 after assembly is also unacceptable. Radially deviating the end cap assembly 80 from its preset position directly causes the rotor assembly 23 to also deviate radially from its preset position, making it difficult to balance the rotational driving force in all radial directions, and thus making it difficult for the impeller 20 to rotate stably. Conversely, axially deviating the end cap assembly 80 from its preset position directly causes the rotor assembly 23 to also deviate axially from its preset position, also resulting in a decrease in the rotational driving force, which in turn reduces the driving efficiency of the impeller 20 and increases the heat generation of the motor 2.

[0039] In an optional embodiment, the drive control component includes a rotation drive control component 60, a suspension drive control component 50, and a drive control circuit board 70 for drive control signal processing. In a working state, the rotation drive control component 60 is used to interact with the rotor rotation component 231 to drive the impeller 20 to rotate around its rotation axis, thereby pumping blood from the blood inlet 14 of the pump head housing to the blood outlet 15 of the pump head housing. In addition, the suspension drive control component 50 is used to interact with the rotor suspension component 232 to achieve stable suspension of the impeller 20 in the pump head housing 10, thereby avoiding contact between the impeller 20 and the pump head housing 10 during rotation.

[0040] In an optional embodiment, as shown in FIG. 1 , the suspension drive control assembly 50 includes a stator yoke 52 and a plurality of stator teeth 51 provided on the stator yoke 52 . The stator teeth 51 are roughly in the shape of an inverted "L", including a vertical portion 512 and a horizontal portion 511 that are perpendicular to each other. The lower surface of the vertical portion 512 is arranged on the stator yoke 52, and the horizontal portion 511 is located at the upper end of the vertical portion 512 and extends radially inward. A coil 53 is provided on the outside of the vertical portion 512, and a stator permanent magnet 54 is provided on the lower surface of the horizontal portion 511. The stator permanent magnet 54 is in a circular ring shape, and a circular axial power body 55 is also provided below the inner side of the stator permanent magnet 54. As disclosed in CN111561519B or CN114748788B, the magnetic field generated by the coil 53 when it is energized acts together with the magnetic fields of the stator permanent magnet 54 and the axial power body 55 on the rotor suspension assembly 232 in the impeller 20, thereby realizing the suspension of the impeller 20.

[0041] In an optional embodiment, as shown in Figure 1, the rotation drive control assembly 60 includes a motor 61 arranged in the accommodating chamber, and the motor 61 includes a motor body and a motor housing (not shown) arranged on the periphery thereof. The output shaft 62 of the motor 61 extends into the center position of the annular recess 82 of the end cover assembly 80, and an active magnet 63 is fixedly connected to the output shaft 62. When the blood pump is working, the active magnet 63 and the passive magnet (not shown) in the rotor rotating assembly 231 are coupled through magnetic force, thereby transmitting the rotational driving force of the motor 2 to the impeller 20, thereby realizing the rotation of the impeller 20.

[0042] In an optional embodiment, the drive control circuit board includes a first drive control circuit board 71 and a second drive control circuit board (not shown). The first drive control circuit board 71 is disposed between the end cap assembly 80 and the coil 53. Electronic components are disposed on the upper surface of the first drive control circuit board 71. The first drive control circuit board 71 is electrically connected to the coil 53 and is used to control the on / off state, direction, and magnitude of the current in the coil 53, thereby adjusting the direction and magnitude of the magnetic flux and achieving centering of the horizontal displacement of the impeller 20. The control method for this part can adopt any suitable existing technology and is not limited or elaborated on in this embodiment. The second drive control circuit board is used to achieve closed-loop control of the motor 2. Its control method, specific structure, and installation location can be found in the description of CN110711275B and are not elaborated on here.

[0043] To improve the motor's heat dissipation and enhance the stability of its internal structure, potting compound can be used to fill the gaps within the motor, surrounding the internal components. Potting compound typically has superior thermal conductivity to air, rapidly transferring heat generated by the motor's internal components to the motor housing, where it is then dissipated to the surrounding environment, thereby dissipating heat from the motor. Furthermore, by fully filling the gaps between the motor's internal components and the housing, the potting compound fully surrounds these components, enhancing structural stability and vibration resistance during subsequent use.

[0044] However, the potting compound is isotropic in terms of thermal conductivity, that is, the potting compound conducts the heat generated by the internal components of the motor to the surroundings indiscriminately. As a result, the temperature of the pump head connected to the motor will also increase accordingly, causing the temperature of the blood pumped inside to increase, and the risk of blood damage will increase.

[0045] On the other hand, reducing the gap between the rotor assembly and the drive control assembly helps to improve the transmission of the force and increase the drive control efficiency. For this reason, the end cover assembly is usually designed to be thinner, which makes it more sensitive to external stress. The volume of the potting compound will change during the curing process, which will release stress to the surrounding parts. When the stress transmitted to stress-sensitive components such as the end cover assembly is too large, the end cover assembly will be deformed by the force, resulting in the pump head being unable to be assembled smoothly or the impeller being tilted after assembly or the impeller position being not centered relative to the pump head housing. In severe cases, it may even cause the end cover assembly to loosen or break.

[0046] In this embodiment, at least a portion of the gap between the drive control assembly and the motor housing 90 is filled with a first potting compound 40, and at least a portion of the inner surface of the end cover assembly 80 is covered with a second potting compound 30, wherein the hardness of the first potting compound 40 after curing is greater than the hardness of the second potting compound 30 after curing, and the thermal conductivity of the first potting compound 40 is higher than the thermal conductivity of the second potting compound 30.

[0047] On the one hand, due to the good thermal conductivity of the first potting compound 40, the heat generated by the drive control component during operation can be quickly and promptly transferred to the motor housing 90, thereby achieving efficient heat dissipation of the motor 2; and due to the poor thermal conductivity of the second potting compound 30, the heat generated by the drive control component during operation can be suppressed from being transferred to the pump head 1, thereby avoiding a sharp rise in the blood temperature in the pump head and reducing the risk of blood damage. That is to say, based on the differentiated design of the first potting compound 40 and the second potting compound 30 in terms of thermal conductivity, directional heat dissipation of the motor is achieved. This directional heat dissipation allows the heat to be basically directed toward the motor housing 90, and finally dissipated to the external environment with the help of the outer surface of the housing. In this way, while achieving heat dissipation, damage to the blood is avoided.

[0048] On the other hand, since the first potting compound 40 is relatively hard after curing, it has a better effect of supporting and positioning the drive control components. When the motor is subjected to external vibration or impact, it can ensure that the drive control components covered by the first potting compound 40 inside the motor do not shift, thereby ensuring the stability of the internal structure of the motor housing. And since the second potting compound 30 is relatively soft after curing, it can fully deform itself, so it can effectively absorb external stress and effectively block the stress generated in other parts from being transmitted to the end cover assembly 80, which can better prevent stress-sensitive components such as the end cover assembly 80 from being deformed or damaged by force. In addition, the soft second potting compound 30 can also play a role in buffering and anti-vibration. During the process of joining the pump head and the motor, it can enable the end cover assembly 80 to withstand the impact of the pump head on the end cover assembly.

[0049] In an optional embodiment, the differentiated design of the first potting glue 40 and the second potting glue 30 in terms of thermal conductivity can be achieved by selecting different types of potting glue. For example, the first potting glue is selected as a potting glue with a thermal conductivity greater than 1.0W / (mK), such as epoxy resin glue, and the second potting glue is selected as a potting glue with a thermal conductivity less than 0.6W / (mK), such as silicone.

[0050] In an optional embodiment, potting compounds with different thermal conductivity coefficients can be obtained by adding modifying materials to the same potting compound. For example, good thermal conductors such as iron powder or aluminum oxide powder can be added to one potting compound, and not added or added in small amounts to another potting compound, thereby forming two potting compounds with different thermal conductivity properties. For another example, poor thermal conductors such as microbubbles and sawdust can be added to one potting compound, and not added or added in small amounts to another potting compound, thereby forming two potting compounds with different overall thermal conductivity coefficients after modification. For another example, a good thermal conductor and a poor thermal conductor can be added to two potting compounds at the same time, respectively, thereby forming a greater difference in thermal conductivity coefficients.

[0051] In an optional embodiment, the selection of the potting compound type and the addition of the modifying material may work simultaneously to enhance the difference in thermal conductivity between the first potting compound 40 and the second potting compound 30 .

[0052] In an optional embodiment, the differentiated design of the hardness of the first potting glue 40 and the second potting glue 30 after curing can also be achieved by selecting different types of potting glue. For example, the first potting glue 40 is selected as a potting glue with a Shore hardness greater than D60 after curing, such as epoxy resin glue, and the second potting glue 30 is selected as a potting glue with a Shore hardness less than 55A after curing, such as silicone.

[0053] In an optional embodiment, potting compounds with different hardness after curing can be obtained by adding modifying additives to the same potting compound. The specific method is similar to the modification of thermal conductivity and will not be repeated here.

[0054] In an optional embodiment, the first potting compound 40 can be cured to form a solid object, and the second potting compound 30 can be cured to form a semi-cured object, thereby achieving a differentiated design of the hardness of the two potting compounds after curing. It should be noted that the term "curing" in this patent does not limit the result after curing, but only refers to the process of hardness change. That is, after curing, it is not necessary to form a solid object, but can also form a semi-solid object.

[0055] In an optional embodiment, the selection of the type of potting compound, the addition of the modifying material, and the selection of whether it becomes solid or semi-solid after curing can be combined and work together to enhance the difference in hardness between the first potting compound and the second potting compound after curing.

[0056] In an optional embodiment, the differentiated design of the potting compound in terms of thermal conductivity and hardness after curing can be achieved in the same or different ways.

[0057] In an optional embodiment, as shown in Figure 1, the inner surface of the end cover assembly 80 includes a lower surface 812 of the disk, an outer peripheral surface 822 of the recessed portion, and a lower end surface 823 of the recessed portion, and the second potting compound 30 includes a first part 31, a second part 32 and a third part 33, which respectively cover a part of the inner surface of the end cover assembly 80.

[0058] Specifically, as shown in Figure 1, after the end cover assembly 80 is assembled in place, a portion of the lower surface 812 of the disk of the end cover assembly 80 and the upper surface of the horizontal portion 511 of the plurality of stator teeth 51 abut against each other to form axial positioning of the end cover assembly 80, and another portion of the lower surface 812 of the disk of the end cover assembly 80 is covered by the first portion 31 of the second potting compound. The first portion 31 of the second potting compound has a low thermal conductivity and can limit the heat generated by components with high heat generation, such as the coil 53 and the first drive control circuit board 71, from being transferred to the end cover assembly 80. On the one hand, it prevents the heat from being further transferred to the blood and causing blood damage, and on the other hand, it also prevents the end cover assembly 80 itself from being deformed by heat. At the same time, after being cured, the first portion 31 of the second potting compound can form a certain support for the adjacent first drive control circuit board 71, the end cover assembly 80, etc., and the cured hardness of the first portion 31 of the second potting compound is low, which can effectively absorb external stress and provide a certain buffer protection when the end cover assembly 80 is subjected to external stress. In particular, the first portion 31 of the second potting compound can also provide buffer protection for the first drive control circuit board 71 , thereby preventing the first drive control circuit board 71 from being deformed and causing damage and failure of electronic components thereon.

[0059] Referring to Figure 1 again, after the end cover assembly 80 is assembled in place, a portion of the outer circumferential surface 822 of the recessed portion of the end cover assembly and the inner circumferential surface of the horizontal portion 511 of the plurality of stator teeth 51 (i.e., the side close to the impeller rotation axis) and the inner circumferential surface of the stator permanent magnet 54 (i.e., the side close to the impeller rotation axis) abut against each other to form radial positioning of the end cover assembly 80. Another portion of the outer circumferential surface 822 of the recessed portion of the end cover assembly is covered by the second portion 32 of the second potting compound. The second portion 32 of the second potting compound has a low thermal conductivity and can limit the heat generated by components with high heat generation, such as the coil 53, from being transferred to the end cover assembly. At the same time, after being cured, the second portion 32 of the second potting compound can form a certain support for the adjacent end cover assembly 80, the coil 53, the stator permanent magnet 54, etc., and the second portion 32 of the second potting compound has a low cured hardness and can effectively absorb external stress and provide a certain buffer protection when the end cover assembly 80 is subjected to external stress.

[0060] Referring again to FIG. 1 , after the end cap assembly 80 is fully assembled, the lower end surface 823 of the recessed portion of the end cap assembly faces the axial power body 55 and is at least partially covered by the third portion 33 of the second potting compound. The third portion 33 of the second potting compound has a low thermal conductivity, which limits the transfer of heat from high-heat-generating components, such as the motor 61, to the end cap assembly 80. Furthermore, after curing, the third portion 33 of the second potting compound provides support for adjacent components, such as the end cap assembly 80, the axial power body 55, and the motor 61. Furthermore, the third portion 33 of the second potting compound has a low hardness upon curing, effectively absorbing external stress and providing a degree of buffering protection against external stress on the end cap assembly 80. In particular, the third portion 33 of the second potting compound also inhibits the transfer of vibration from the motor 61 to the end cap assembly 80.

[0061] In an optional embodiment, the first part 31, the second part 32 and the third part 33 of the second potting glue can be designed as second potting glues with different performances according to the differences in heat transfer, force and other factors at each position to further optimize its performance in heat transfer, force and other aspects, as long as they all meet the requirements that the hardness of the first potting glue 40 after curing is greater than the hardness of the second potting glue 30 after curing, and the thermal conductivity coefficient of the first potting glue 40 is higher than the thermal conductivity coefficient of the second potting glue 30.

[0062] In an optional embodiment, the first part 31 , the second part 32 and the third part 33 of the second potting compound may be selected to be potting compounds with the same performance, such as the same potting compound, to reduce costs and simplify the assembly process.

[0063] In an optional embodiment, the first potting compound 40 includes a portion A 41 and a portion B 42 , and these two portions respectively fill a portion of the gap between the drive control assembly and the motor housing 90 .

[0064] Specifically, as shown in Figure 1, part A 41 of the first potting glue is filled between the suspension drive control component 50 and the motor housing 90. Part A 41 of the first potting glue has a high thermal conductivity and can quickly and effectively transfer the heat generated by components with high heat generation, such as the coil 53 and the first drive control circuit board 71, to the motor housing 90; at the same time, part A 41 of the first potting glue has a high hardness after curing, and can form a stable support for the suspension drive control component 50, thereby ensuring the structural stability for long-term use.

[0065] Referring again to Figure 1 , portion B 42 of the first potting compound is placed between the rotary drive control assembly 60 and the motor housing 90 . Portion B 42 of the first potting compound has a high thermal conductivity, enabling it to quickly and effectively transfer heat generated by high-heat-generating components, such as the motor 61, to the motor housing 90 . Furthermore, portion B 42 of the first potting compound exhibits a high degree of hardness after curing, providing a stable support for the rotary drive control assembly 60 and ensuring structural stability for long-term use. It should be noted that portion B 42 of the first potting compound does not directly contact the rotating parts of the rotary drive control assembly 60 to avoid affecting its normal operation.

[0066] In an optional embodiment, heat dissipation fins 91 are further provided around the motor housing 90 . With the help of the heat dissipation fins 91 , the heat transferred to the motor housing 90 can be quickly and effectively dissipated to the external environment.

[0067] In an optional embodiment, part A 41 and part B 42 of the first potting glue can be designed as first potting glues with different performances according to the differences in heat transfer, force and other factors at each position to further optimize its performance in heat transfer, force and other aspects, as long as they both meet the conditions that the hardness of the first potting glue 40 after curing is greater than the hardness of the second potting glue 30 after curing, and the thermal conductivity of the first potting glue 40 is higher than the thermal conductivity of the second potting glue 30.

[0068] In an optional embodiment, the A portion 41 and the B portion 42 of the first potting compound may be selected to be potting compounds with the same performance, such as the same type of potting compound, to reduce costs and simplify the assembly process.

[0069] As previously mentioned, after the end cap assembly 80 is assembled, a portion of the end cap assembly's lower surface 812 abuts against the upper surfaces of the stator teeth's horizontal portions 511, forming multiple axial positions for the end cap assembly 80. The accuracy of each axial position and the consistency of these multiple axial positions are crucial to the blood pump's hydraulic performance and driving efficiency. During the assembly of the end cap assembly 80, the first portion 31 of the second potting compound is inevitably squeezed. If the lower surface 812 of the end cap assembly is flat, the first portion 31 of the second potting compound will be squeezed into the space between the upper surface of the stator teeth' horizontal portions 511 and the end cap assembly 80. This uncontrolled process may affect the accuracy of each axial position and the consistency of these multiple axial positions, resulting in the height of the upper surface 811 of the end cap assembly 80 deviating from the preset target or causing the upper surface 811 of the end cap assembly 80 to be uneven. In either case, the hydraulic performance and driving efficiency of the blood pump will be affected.

[0070] To avoid the above situation, in an optional embodiment, a plurality of downwardly protruding protrusions 83 are formed on the lower surface 812 of the disk of the end cover assembly, and the plurality of protrusions 83 correspond one-to-one to the horizontal portions 511 of the plurality of stator teeth. In this way, when the coating of the first portion 31 of the second potting compound is completed and the end cover assembly 80 is covered on the upper end of the motor housing 90, the protrusions 83 can first contact the horizontal portion 511; when the protrusions 83 contact the horizontal portion 511, other areas of the lower surface 812 of the disk of the end cover assembly may not have yet contacted the first portion 31 of the second potting compound, or even if they contact the first portion 31 of the second potting compound, they do not cause overflow flow, or even if they cause overflow flow of the first portion 31 of the second potting compound, they have not yet flowed to the portion between the protrusions 83 and the horizontal portion 511. In this way, in the process of subsequently fastening the end cover assembly 80 to the motor housing 90, although the end cover assembly 80 continues to press down and squeeze the first part 31 of the second potting compound, the protrusion 83 has completely fit with the horizontal part 511, and the fit is getting tighter and tighter, effectively preventing the first part 31 of the second potting compound from entering between the two, avoiding affecting the positioning accuracy of each axial positioning and the consistency between multiple axial positioning.

[0071] In addition, since the thickness of the end cover assembly 80 at the position where the protrusion 83 is formed is greater than the thickness at other positions, that is, the end cover assembly 80 forms the protrusion 83 by thickening downward in a partial area, therefore, under the condition of the same material, the stiffness of the end cover assembly 80 at the position where the protrusion 83 is formed is greater than the stiffness at other positions, and the positioning accuracy of the axial positioning performed by combining the protrusion 83 with the horizontal part 511 is also higher.

[0072] The exemplary embodiments of this patent have been described above in conjunction with the accompanying drawings. However, those skilled in the art will appreciate that this patent is not limited to the specific structures disclosed. Various changes and modifications may be made to the exemplary embodiments of this patent without departing from the spirit and scope of this patent. All such changes and modifications are intended to be within the scope of protection defined by the claims of this patent.

Claims

1. A motor for an extracorporeal blood pump, adapted to engage with a pump head of the extracorporeal blood pump, the motor comprising: a motor housing, wherein an accommodating chamber is formed inside the motor housing; an end cover assembly disposed at the upper end of the motor housing, the end cover assembly having an inner surface and an outer surface, the inner surface of the end cover assembly facing the accommodating chamber, and the outer surface of the end cover assembly being used to engage the pump head; a drive control component, disposed in the accommodating chamber, for driving the impeller in the pump head to rotate and / or controlling the suspension of the impeller in the pump head; a first potting compound filling at least a portion of a gap between the drive control assembly and the motor housing; a second potting compound covering at least a portion of an inner surface of the end cap assembly; The hardness of the first potting glue after curing is greater than the hardness of the second potting glue after curing, and the thermal conductivity of the first potting glue is higher than the thermal conductivity of the second potting glue.

2. The motor according to claim 1, wherein the first potting compound and the second potting compound are two potting compounds with different thermal conductivities, and / or the first potting compound and the second potting compound are modified by different methods in terms of thermal conductivity.

3. The motor according to claim 1 , wherein the first potting compound and the second potting compound are two potting compounds having different hardnesses after curing, and / or the first potting compound and the second potting compound are modified by different methods in terms of hardness after curing, and / or the first potting compound and the second potting compound are solid and semi-solid, respectively, after curing.

4. The motor according to claim 1, wherein the first potting compound is epoxy resin glue, and the second potting compound is silicone glue.

5. The motor according to claim 1, wherein the end cover assembly includes a disk surface, the center of the disk surface is recessed to form a recessed portion, the inner surface of the end cover assembly includes a lower surface of the disk surface, an outer peripheral surface of the recessed portion, and a lower end surface of the recessed portion, and the second potting compound covers at least a portion of the lower surface of the disk surface and / or the outer peripheral surface of the recessed portion and / or the lower end surface of the recessed portion.

6. The motor according to claim 1, wherein the drive control assembly comprises a first drive control circuit board, the first drive control circuit board is arranged below the end cover assembly, and the second potting compound covers at least a portion of an upper surface of the first drive control circuit board. 7 . The motor according to claim 1 , wherein the drive control assembly comprises a suspension drive control assembly, and the first potting compound fills at least a portion of a gap between the suspension drive control assembly and the motor housing. 8 . The motor according to claim 1 , wherein the drive control assembly comprises a rotation drive control assembly, and the first potting compound fills at least a portion of a gap between the rotation drive control assembly and the motor housing.

9. The motor according to claim 1, wherein the drive control assembly includes a suspension drive control assembly, and the suspension drive control assembly includes a plurality of stator teeth; each of the stator teeth includes a horizontal portion, and the inner surface of the end cover assembly is formed with a plurality of downwardly protruding protrusions, the plurality of protrusions correspond one-to-one to the horizontal portions of the plurality of stator teeth, and the plurality of protrusions are respectively directly abutted against the horizontal portions of the plurality of stator teeth.

10. An extracorporeal blood pump, comprising: A motor as described in any one of claims 1-9; And A pump head, the pump head being detachably engaged with the motor, the pump head comprising a pump housing and an impeller received in the pump housing; the impeller comprises a rotor assembly, and the rotor assembly can drive the impeller to rotate and / or levitate under the action of the driving and controlling assembly.

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