A drip irrigation hollow cup motor

Abstract

The present invention provides a drip irrigation hollow cup motor. The drip irrigation hollow cup motor comprises a stator assembly, a rotor assembly and a housing; the rotor assembly comprises a magnetic steel and an axis core, the axis core is passed through the center of the magnetic steel, one end of the axis core passes through the front end cover, a barrier is arranged inside the end of the front end cover away from the housing, the barrier is sleeved outside the axis core, and has a first end and a second end, the second end is sealed and connected to the inner wall of the front end cover, the rear end cover is connected to a delivery pipe for inputting nutrient solution, when the drip irrigation pressure of the delivery pipe is greater than the pressure of the heart pumping blood, the first end radially expands so that a gap is formed between the inner wall of the first end and the axis core, allowing the nutrient solution to flow out; when the drip irrigation pressure of the delivery pipe is less than or equal to the pressure of the heart pumping blood, the inner wall of the first end abuts against the axis core and holds the axis core tightly, preventing blood from flowing in. The present invention allows the nutrient solution to pass through and prevents blood from entering the interior, thereby protecting the hollow cup motor.

Description

Technical Field

[0001] The invention relates to the technical field of coreless cup motors, in particular to a drip irrigation coreless cup motor. Background Art

[0002] Coreless motors are often used in medical equipment due to their small size, high efficiency and stable operation. Currently, coreless motors can be made within 5mm. In conventional heart surgery, the working time of a heart pump driven by a coreless motor is about one day. However, with the development of current technology and the increasing requirements for medical safety, in some cases the heart pump needs to work for another week after surgery. Therefore, the coreless motor of the heart pump is required to meet the needs of long-term stable operation.

[0003] At present, the hollow cup motors of short-term working heart pumps often use seals to achieve the sealing between the motor and the outside. The seals rub against the shaft, and after working for a long time, a gap will be rubbed out, the seal fails, and blood flows into the motor. Although there is a parylene polymer membrane inside the motor for biocompatibility protection, the parylene polymer membrane is not strong enough under long-term blood infusion and flushing, and there is a risk of damage. This is also the reason why short-term working heart pumps cannot provide long-term assistance after surgery. Therefore, hollow cup motors that meet the requirements of long-term work need to use a glue film layer with high bonding strength as a protective layer. But even so, from the perspective of optimal design, blood should not enter the inside of the motor. Therefore, designing a structure that ensures that blood does not enter the inside of the motor is the current difficulty. Summary of the invention

[0004] The technical problem solved by the embodiment of the present invention mainly lies in how to prevent blood from entering the interior of the coreless cup motor while allowing the nutrient solution to be pumped into the heart through the interior of the coreless cup motor, thereby protecting the coreless cup motor.

[0005] In order to solve the above technical problems, an embodiment of the present invention provides a drip irrigation hollow cup motor. The drip irrigation hollow cup motor includes a stator assembly, a rotor assembly and a casing; the stator assembly is arranged in the casing, the stator assembly is provided with a cavity penetrating along the axial direction, the rotor assembly is rotatably inserted into the cavity, the casing is sleeved on the outer wall of the stator assembly, and the two ends of the casing are respectively provided with a front cover and a rear cover for closing the casing, and it is characterized in that the rotor assembly includes a magnet and an axis core, the axis core is inserted through the center of the magnet, one end of the axis core passes through the front cover, and the other end is arranged in the rear cover, and a barrier is arranged inside the end of the front cover away from the casing, the barrier is sleeved outside the axis core, and the barrier is tubular , and having a first end and a second end, the second end is sealed and connected to the inner wall of the front end cover, the rear end cover is connected to a delivery tube for inputting nutrient solution, the delivery tube delivers nutrient solution to the heart via the inside of the hollow cup motor, the drip irrigation pressure when the delivery tube delivers nutrient solution is greater than the pressure of the heart pumping blood, the inner wall pressure of the barrier is greater than the outer wall pressure, the first end radially expands to form a gap between the inner wall of the first end and the shaft core, allowing the nutrient solution to flow out; the drip irrigation pressure when the delivery tube replenishes nutrient solution is less than or equal to the pressure of the heart pumping blood, the inner wall pressure of the barrier is less than or equal to the outer wall pressure, the inner wall of the first end abuts against and holds the shaft core tightly to prevent blood from flowing in.

[0006] Optionally, the barrier comprises a concave barrier, the outer contour of the concave barrier is in the shape of a trumpet that is concave inwards, the cross section of the concave barrier is in the shape of a circular ring, and the edge of the vertical cross section is in the shape of an arc that is concave inwards.

[0007] Optionally, the upper edge of the vertical cross-section of the concave barrier forms an endpoint a at the first end and an endpoint c at the second end. The vertical reference line passing through endpoint a intersects the center perpendicular line of line segment ac at point o. The arc-shaped upper edge of the concave barrier is located on a circle with point o as the center and endpoints a and c as points on the circle. At this time, endpoint a is the lowest point of the circle.

[0008] Optionally, the barrier member comprises a bevel barrier member, the outer contour of the bevel barrier member is in the shape of a truncated cone, the cross section of the bevel barrier member is in the shape of a circular ring, and the vertical cross section is in the shape of a trapezoid.

[0009] Optionally, the barrier comprises a multi-curved barrier, the outer contour of which is formed by multiple curved surfaces connected axially, the cross section of which is circular, and the edge of the vertical section is formed by multiple inwardly concave arcs connected in sequence.

[0010] Optionally, the barrier member is made of a flexible polymer material.

[0011] Optionally, the second end of the barrier member is bonded to the front end cover by glue applied to the inner wall of the front end cover.

[0012] Optionally, the first end of the barrier is connected to the shaft core by interference fit.

[0013] Optionally, a protective cover is provided on the outside of one end of the front end cover away from the housing, and the protective cover is provided outside the barrier and forms a distance between the protective cover and the first end of the barrier.

[0014] Optionally, a connection cover is provided on the outside of one end of the rear end cover away from the housing, and the delivery pipe is sealedly connected to the connection cover and communicates with the interior of the coreless cup motor.

[0015] Optionally, the inner wall of the stator assembly is provided with a stator protection cover or the inner wall of the stator assembly is bonded with a polymer stator protection layer by glue, and the stator protection cover or the polymer stator protection layer isolates and seals the stator assembly; the outer wall of the magnetic steel is provided with a rotor protection cover or the outer wall of the magnetic steel is bonded with a polymer rotor protection layer by glue, and the rotor protection cover or the polymer rotor protection layer isolates and seals the magnetic steel; the stator protection cover and the rotor protection cover are both metal sleeves; the polymer stator protection layer and the polymer rotor protection layer both include a biocompatible polymer material tube.

[0016] Compared with the prior art, the technical solution of the embodiment of the present invention has beneficial effects.

[0017] For example, the drip irrigation hollow cup motor of the present invention has a barrier member arranged on the front end cover, the barrier member is sleeved outside the shaft core, the inner wall of the first end of the barrier member abuts against the shaft core, and the second end is sealed and connected to the inner wall of the front end cover. When the delivery tube delivers nutrient solution to the heart through the interior of the hollow cup motor, the pressure of the nutrient solution dripped by the delivery tube is greater than the pressure of the heart pumping blood, the pressure of the inner wall of the barrier member is greater than the pressure of the outer wall, and the first end radially expands to form a gap between the inner wall of the first end and the shaft core, allowing the nutrient solution to flow out; when the delivery tube replenishes the nutrient solution, the pressure of the nutrient solution dripped by the delivery tube is less than or equal to the pressure of the heart pumping blood, the pressure of the inner wall of the barrier member is less than or equal to the pressure of the outer wall, and the inner wall of the first end hugs the shaft core to prevent blood from flowing in. There is no need for a rotating seal between the seal and the shaft core to prevent blood from entering the interior of the motor, thereby avoiding wear and failure of the seal that causes blood to enter the interior of the motor and affect the motor performance, thereby extending the service life.

[0018] For another example, the barrier is configured as a concave structure. Under the same blood flow rate and pressure and the same boundary conditions of the barrier, the radial inner deformation is greater and the sealing effect is better.

[0019] For another example, a protective sleeve or a protective layer is used to protect the stator assembly and the rotor assembly, thereby protecting the non-biocompatible materials of the motor. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 is a cross-sectional view of a drip irrigation hollow cup motor conveying nutrient solution in an embodiment of the present invention;

[0021] Figure 2 is a cross-sectional view of the drip irrigation hollow cup motor in the embodiment of the present invention when supplementing nutrient solution;

[0022] Figure 3 is a schematic diagram of the structure of a concave barrier in an embodiment of the present invention;

[0023] Figure 4 is a cross-sectional view of a concave barrier member in an embodiment of the present invention;

[0024] Figure 5 is a diagram showing changes in the upper edge of a vertical cross section of a concave barrier in an embodiment of the present invention;

[0025] Figure 6 is a schematic diagram of the structure of a bevel barrier in an embodiment of the present invention;

[0026] Figure 7 is a schematic diagram of the structure of a multi-curved barrier in an embodiment of the present invention;

[0027] Figure 8 is a cloud diagram of radial variation of the beveled edge barrier in an embodiment of the present invention;

[0028] Fig. 9 It is a cloud diagram of radial variation of the concave barrier in the embodiment of the present invention.

[0029] In the figure:

[0030] 1. Protective cover; 2. Rotor assembly; 21. Shaft core, 22. Magnet; 3. Barrier; 31. Concave barrier; 32. Bevel barrier; 33. Multi-curved barrier; 34. First end; 35. Second end; 4. Front cover; 5. Connecting cover; 6. Delivery pipe; 7. Stator assembly; 8. Rear cover; 9. Casing. DETAILED DESCRIPTION

[0031] In order to make the purpose, features and beneficial effects of the present invention more obvious and easy to understand, the specific embodiments of the present invention are described in detail below in conjunction with the accompanying drawings. It is understandable that the specific embodiments described below are only used to explain the present invention, rather than to limit the present invention. In addition, the same or similar reference numerals may be used in the figures to refer to the same or similar elements in different embodiments, and the description of the same or similar elements in different embodiments and the description of the prior art elements, features, effects, etc. may be omitted; it should be noted that the axial, radial and circumferential directions of the embodiments of the present invention respectively represent the axial, radial and circumferential directions of the rotor assembly 2.

[0032] Reference Figure 1-Figure 9 , an embodiment of the present invention provides a drip irrigation hollow cup motor.

[0033] Specifically, the drip irrigation hollow cup motor includes a stator assembly 7, a rotor assembly 2 and a casing 9; the stator assembly 7 is arranged in the casing 9, the stator assembly 7 is provided with a cavity penetrating along the axial direction, the rotor assembly 2 is rotatably arranged in the cavity, the casing 9 is sleeved on the outer wall of the stator assembly 7, and the two ends of the casing 9 are respectively provided with a front end cover 4 and a rear end cover 8 for closing the casing 9, the rotor assembly 2 includes a magnetic steel 22 and an axis core 21, the axis core 21 is penetrated in the center of the magnetic steel 22, one end of the axis core 21 passes through the front end cover 4, and the other end is arranged in the rear end cover 8, and a barrier 3 is arranged inside the end of the front end cover 4 away from the casing 9, and the barrier 3 is sleeved outside the axis core 21, and the barrier 3 is tubular and has a first end 34 and the second end 35, the second end 35 is sealedly connected to the inner wall of the front end cover 4, and the rear end cover 8 is connected to the delivery tube 6 for inputting nutrient solution, and the delivery tube 6 delivers nutrient solution to the heart through the inside of the hollow cup motor. When the drip irrigation pressure when the delivery tube 6 delivers nutrient solution is greater than the pressure of the heart pumping blood, the inner wall pressure of the barrier 3 is greater than the outer wall pressure, and the first end 34 expands radially to form a gap between the inner wall of the first end 34 and the shaft core 21, allowing the nutrient solution to flow out; when the drip irrigation pressure when the delivery tube 6 replenishes the nutrient solution is less than or equal to the pressure of the heart pumping blood, the inner wall pressure of the barrier 3 is less than or equal to the outer wall pressure, and the inner wall of the first end 34 abuts against and holds the shaft core 21 to prevent blood from flowing in.

[0034] See also Figure 3 and Figure 4 In some embodiments, the barrier 3 includes a concave barrier 31, the outer contour of the concave barrier 31 is in the shape of a trumpet that is concave inwards, the cross section of the concave barrier 31 is in the shape of a circular ring, and the edge of the vertical section is in the shape of an arc that is concave inwards.

[0035] See also Figure 4 and Figure 5In some embodiments, the upper edge of the vertical cross section of the concave barrier 31 forms an endpoint a at the first end 34 and an endpoint c at the second end 35. The vertical reference line passing through the endpoint a intersects the central perpendicular line of the line segment ac at point o, and the arc-shaped upper edge of the concave barrier is located on a circle with point o as the center and endpoints a and c as points on the circle ( Figure 5 When the solid circle in the figure is on the solid circle), endpoint a is the lowest point of the circle, the effective area of ​​the outer arc surface of the concave barrier 31 is the largest, the degree of depression is the largest when subjected to pressure, the radial deformation is the largest, and the sealing effect of holding the shaft core 21 is the best; at this time, the length of the arc ac is r*(180°-2β)*π / 180°; wherein, r is the radius of the circle where the arc ac is located, β is the angle between the radius oa and the line segment ac, the line segment co1 is perpendicular to the radius oa, o1 is the intersection of the line segment co1 and the radius oa, tanβ=co1 / ao1, wherein co1 is the length of the line segment co1, and ao1 is the length of the line segment ao1, then the radius of the circle where the arc ac is located can be calculated to be r=sinβ*ac / sin(180°-2β), wherein ac is the length of the line segment ac.

[0036] When the circle where the arc ac lies ( Figure 5 The lowest point of the dotted circle appears when the end point a is close to the end point c, that is, point d ( Figure 5 The intersection of the middle dotted circle and the vertical dotted line), at this time, the interference between the concave barrier 31 and the shaft core 21 will be too large, resulting in it being difficult to be flushed by the nutrient solution; when the circle where the arc ac is located ( Figure 5 When the midpoint dashed circle) appears on the side of endpoint a away from endpoint c, that is, point e ( Figure 5 The intersection of the midpoint dashed circle and the vertical dashed line), at this time, the length of the arc ac is shorter, the concave curvature is lower, the effective contact area is smaller, and when it plays a unidirectional isolation role, the axial clamping deformation and force are smaller. Therefore, the most preferred situation is when the endpoint a is the lowest point of the arc.

[0037] See also Figure 6 In some embodiments, the barrier 3 includes a bevel barrier 32, the outer contour of the bevel barrier 32 is in the shape of a truncated cone, the cross section of the bevel barrier 32 is in the shape of a circular ring, and the vertical cross section is in the shape of a trapezoid.

[0038] See also Figure 7 In some embodiments, the barrier 3 includes a multi-curved barrier 33, the outer contour of which is formed by multiple curved surfaces connected axially, the cross-section of the multi-curved barrier 33 is circular, and the edge of the vertical section is formed by multiple inwardly concave arcs connected in sequence.

[0039] In some embodiments, for different working conditions, the barrier 3 can also be set as a convex barrier with an outer contour protruding outward, a multi-bevel barrier with an outer contour of multiple sections connected in sequence in the shape of a truncated cone, and other barriers with curved surface structures. The cross-section must be circular and the diameter must gradually increase from the first end 34 to the second end 35.

[0040] In some embodiments, the material of the barrier 3 is a flexible polymer material, which has high flexibility and biocompatibility. The material of the barrier 3 can be PET (polyethylene terephthalate), PDMS (polydimethylsiloxane), PTFE (polytetrafluoroethylene), polycarbonate or polyisocyanate, etc.

[0041] In some embodiments, the outer diameter φD of the second end 35 of the barrier member 3 is smaller than the inner diameter φC of the front end cover 4, and the second end 35 of the barrier member 3 is gap-fitted with the front end cover 4 and bonded with glue coated on the inner wall of the front end cover 4; the barrier member 3 and the front end cover 4 can also be connected in other ways, as long as the second end 35 of the barrier member 3 is sealed and connected to the inner wall of the front end cover 4.

[0042] In some embodiments, when the barrier 3 is in a natural state without being sleeved on the shaft core 21 , the inner diameter φB of the first end 34 of the barrier 3 is smaller than the outer diameter φA of the shaft core 21 , and the first end 34 of the barrier 3 is connected to the shaft core 21 by interference fit.

[0043] In some embodiments, a protective cover 1 is provided on the outside of the end of the front cover 4 away from the housing 9. The protective cover 1 is covered outside the barrier 3 and is spaced apart from the first end 34 of the barrier 3 internally. The L between the first end 34 of the barrier 3 and the front end inner wall of the protective cover 1 must satisfy L≥0.1mm to prevent interference caused by tolerance accumulation during assembly.

[0044] In some embodiments, a connection cover 5 is disposed outside the end of the rear end cover 8 away from the housing 9, and the delivery pipe 6 is sealedly connected to the connection cover 5 and communicated with the interior of the hollow cup motor.

[0045] In some embodiments, the inner wall of the stator assembly 7 is provided with a stator protective cover, which isolates and seals the stator assembly 7; the outer wall of the magnetic steel 22 is provided with a rotor protective cover, which isolates and seals the magnetic steel 22 to achieve protection of the motor's non-biocompatible materials.

[0046] In some embodiments, the inner wall of the stator assembly 7 is provided with a stator protective sleeve or the inner wall of the stator assembly 7 is bonded with a polymer stator protective layer by glue, and the stator protective sleeve or the polymer stator protective layer isolates and seals the stator assembly; the outer wall of the magnetic steel 22 is provided with a rotor protective sleeve or the outer wall of the magnetic steel 22 is bonded with a polymer rotor protective layer by glue, and the rotor protective sleeve or the polymer rotor protective layer isolates and seals the magnetic steel; and the protection of the motor without biocompatible materials is realized. The stator protective sleeve and the rotor protective sleeve are both metal sleeves, such as titanium alloy sleeves; the polymer stator protective layer and the polymer rotor protective layer both include biocompatible polymer material tubes, such as PET (polyethylene terephthalate), PEEK (polyetheretherketone) and other polymer material tubes.

[0047] Figure 8 is a cloud diagram of radial variation of the beveled edge barrier in an embodiment of the present invention; Fig. 9 It is a cloud diagram of radial variation of the concave barrier in the embodiment of the present invention.

[0048] See also Figure 8 and Fig. 9 The bevel barrier 32 and the concave barrier 31 are placed in the fluid for fluid simulation. Under the same liquid flow rate and hydraulic pressure, the influence of the fluid pressure on the radial deformation of the bevel barrier 32 and the concave barrier 31 is analyzed and compared. Figure 8 and Fig. 9 From the simulation results, it can be seen that under the same boundary conditions, the radial deformation of the concave structure is large, the radial deformation of the concave surface is about 1.4 times that of the inclined surface, and the force of holding the shaft core 21 is large; the concave barrier 31 has better sealing performance.

[0049] In summary, in the drip irrigation hollow cup motor of the present invention, a barrier member 3 is arranged on the front end cover 4, and the barrier member 3 is sleeved outside the shaft core 21. The inner wall of the first end 34 of the barrier member 3 abuts against the shaft core 21, and the second end 35 is sealed and connected with the inner wall of the front end cover 4. When the delivery tube 6 delivers nutrient solution to the heart through the interior of the hollow cup motor, the pressure of the nutrient solution dripped by the delivery tube 6 is greater than the pressure of the heart pumping blood, the inner wall pressure of the barrier member 3 is greater than the outer wall pressure, and the first end 34 expands radially to form a gap between the inner wall of the first end 34 and the shaft core 21, allowing the nutrient solution to flow out; when the delivery tube 6 replenishes the nutrient solution, the pressure of the nutrient solution dripped by the delivery tube 6 is less than or equal to the pressure of the heart pumping blood, the inner wall pressure of the barrier member 3 is less than or equal to the outer wall pressure, and the inner wall of the first end 34 hugs the shaft core 21 to prevent blood from flowing in. There is no need for a rotating seal between the seal and the shaft core 21 to prevent blood from entering the interior of the motor, thereby avoiding wear and failure of the seal to cause blood to enter the interior of the motor and affect the motor performance, thereby extending the service life.

[0050] Furthermore, the barrier 3 of the present invention is configured as a concave structure. Under the same blood flow rate and pressure and the same boundary conditions, the barrier 3 has a larger radial inward deformation and a better sealing effect.

[0051] Furthermore, the present invention adopts a protective sleeve or provides a protective layer to protect the stator assembly 7 and the rotor assembly 2, thereby realizing the protection of the biocompatible material of the motor.

[0052] Although specific embodiments have been described above, these embodiments are not intended to limit the scope of the present disclosure, even when only a single embodiment is described with respect to specific features. The feature examples provided in the present disclosure are intended to be illustrative rather than limiting, unless otherwise stated. In specific implementations, the technical features of one or more dependent claims may be combined with the technical features of the independent claims, based on actual needs and where technically feasible, and the technical features from the corresponding independent claims may be combined in any appropriate manner rather than just by the specific combinations listed in the claims.

[0053] Although the present invention is disclosed as above, the present invention is not limited thereto. Any person skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the scope defined by the claims.

Claims

1. A drip irrigation coreless cup motor, comprising a stator assembly, a rotor assembly and a casing; the stator assembly is arranged in the casing, the stator assembly is provided with a cavity penetrating along the axial direction, the rotor assembly is rotatably arranged in the cavity, the casing is sleeved on the outer wall of the stator assembly, and the two ends of the casing are respectively provided with a front end cover and a rear end cover for closing the casing, characterized in that: The rotor assembly includes a magnetic steel and an axis core, the axis core is passed through the center of the magnetic steel, one end of the axis core passes through the front end cover, and the other end is arranged in the rear end cover, a barrier is arranged inside the end of the front end cover away from the housing, the barrier is sleeved outside the axis core, the barrier is tubular, and has a first end and a second end, the second end is sealed and connected to the inner wall of the front end cover, the rear end cover is connected to a delivery pipe for inputting nutrient solution, the delivery pipe delivers nutrient solution to the heart through the inside of the hollow cup motor, the drip irrigation pressure of the delivery pipe when delivering nutrient solution is greater than the pressure of the heart pumping blood, the inner wall pressure of the barrier is greater than the outer wall pressure, the first end radially expands to form a gap between the inner wall of the first end and the axis core, allowing the nutrient solution to flow out; the drip irrigation pressure of the delivery pipe when replenishing nutrient solution is less than or equal to the pressure of the heart pumping blood, the inner wall pressure of the barrier is less than or equal to the outer wall pressure, the inner wall of the first end abuts against the axis core and holds the axis core tightly to prevent blood from flowing in; the barrier includes a concave barrier The outer contour of the concave barrier is in the shape of a trumpet that is concave inwards, the cross section of the concave barrier is in the shape of a circular ring, and the edge of the vertical section is in the shape of an arc that is concave inwards; the upper edge of the vertical section of the concave barrier forms an endpoint a at the first end and an endpoint c at the second end, and the vertical reference line passing through the endpoint a intersects the central perpendicular line of the line segment ac at point o, and the arc-shaped upper edge of the concave barrier is located on a circle with point o as the center and endpoints a and c as points on the circle, at which point endpoint a is the lowest point of the circle, and the length of the arc ac is The degree is r*(180°-2β)*π / 180°; where r is the radius of the circle where the arc ac is located, β is the angle between the radius oa and the line segment ac, the line segment co1 is perpendicular to the radius oa, o1 is the intersection of the line segment co1 and the radius oa, tanβ=co1 / ao1, where co1 is the length of the line segment co1, ao1 is the length of the line segment ao1, and the radius of the circle where the arc ac is located r=sinβ*ac / sin(180°-2β), where ac is the length of the line segment ac.

2. The drip irrigation hollow cup motor according to claim 1, characterized in that: The material of the barrier is a flexible polymer material.

3. The drip irrigation hollow cup motor according to claim 1, characterized in that: The second end of the blocking member is bonded to the front end cover by glue applied to the inner wall of the front end cover.

4. The drip irrigation hollow cup motor according to claim 1, characterized in that: The first end of the blocking member is connected to the shaft core by interference fit.

5. The drip irrigation coreless cup motor according to claim 1, characterized in that: A protective cover is arranged outside the end of the front end cover away from the housing. The protective cover is arranged outside the blocking member and forms a distance between the protective cover and the first end of the blocking member.

6. The drip irrigation coreless cup motor according to claim 1, characterized in that: A connection cover is arranged outside the end of the rear end cover away from the housing, and the delivery pipe is sealedly connected to the connection cover and communicated with the interior of the coreless cup motor.

7. The drip irrigation coreless cup motor according to claim 1, characterized in that: The inner wall of the stator assembly is provided with a stator protection cover or the inner wall of the stator assembly is bonded with a polymer stator protection layer by glue, and the stator protection cover or the polymer stator protection layer isolates and seals the stator assembly; the outer wall of the magnetic steel is provided with a rotor protection cover or the outer wall of the magnetic steel is bonded with a polymer rotor protection layer by glue, and the rotor protection cover or the polymer rotor protection layer isolates and seals the magnetic steel; the stator protection cover and the rotor protection cover are both metal sleeves; the polymer stator protection layer and the polymer rotor protection layer both include a biocompatible polymer material tube.

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