Blood perfusion adsorber

Abstract

The utility model provides a blood perfusion adsorber, and belongs to the technical field of perfusion devices. The hemoperfusion device solves the problem that an existing hemoperfusion device is poor in sealing reliability due to the fact that end face sealing is adopted. The blood perfusion adsorber comprises a cylindrical shell, a filter screen rack, an end cover and a locking nut are arranged at the two ends of the shell respectively, the filter screen rack is located in the shell and abuts against an inner annular step of the shell, the end cover is located in the shell and pressed on the filter screen rack, the locking nut is pressed on the end cover, and the filter screen rack is located in the shell and abuts against the inner annular step of the shell. A sealing ring is arranged between the outer ring face of the end cover and the inner ring face of the shell, an internal thread is arranged on the locking nut, an external thread is arranged on the shell, and the cross section of the external thread and the cross section of the internal thread are in a right trapezoid shape. The sealing mode is radial sealing, and the extrusion degree of the sealing ring is irrelevant to the pre-tightening force of the threads; the end cover and the locking nut are designed in a split manner, and the required pretightening force is small, so that the sealing reliability is improved; the cross sections of the external threads and the internal threads are right-angled trapezoids, so that the creep resistance of the threads can be improved.

Description

Technical Field

[0001] This utility model belongs to the field of perfusion device technology and relates to a blood perfusion adsorber. Background Technology

[0002] Most perfusion devices on the market have a cylindrical shell with end caps at the top and bottom. The end caps have blood inlets and outlets. Blood flows in from the bottom of the perfusion device and flows out from the top. The resin inside the device adsorbs the lipid-soluble macromolecules in the blood, thus purifying the blood. The resin must be isolated inside the perfusion device shell by a filter screen frame and cannot flow out of the perfusion device with the blood. The perfusion device must be sealed to prevent leakage.

[0003] For example, Chinese patent application number 2022226449286 discloses a hemoperfusion device housing, including a cylindrical outer shell with end caps at both ends. Each end cap has a pressure cap between its perimeter and the corresponding outer wall of the outer shell end. A sealing ring is located between the end cap and the outer shell, and the sealing ring is pressed tightly between the end of the outer shell and the inner surface of the end cap. A higher preload force results in a better seal. However, to achieve the desired sealing effect, a large preload force is required, leading to excessive stress between the threads. Higher stress makes the plastic threads prone to creep deformation. During high-temperature sterilization, the plastic threads are also prone to creep deformation, resulting in insufficient locking force or reverse loosening, thus reducing the sealing effect and even failing to meet the sealing requirements for clinical use. Utility Model Content

[0004] The purpose of this invention is to address the aforementioned problems in existing technologies by proposing a blood perfusion adsorber with a highly reliable sealing structure.

[0005] The objective of this utility model can be achieved through the following technical solutions:

[0006] A blood perfusion adsorber includes a cylindrical shell with a filter screen frame, an end cap, and a locking nut at each end. The filter screen frame is located inside the shell and abuts against an inner annular step. The end cap is located inside the shell and presses against the filter screen frame. The locking nut presses against the end cap. A sealing ring is provided between the outer annular surface of the end cap and the inner annular surface of the shell. The locking nut has an internal thread, and the shell has an external thread. The cross-sections of both the external and internal threads are right-angled trapezoids.

[0007] When the lock nut is connected to the housing, the external and internal threads mesh to form a threaded connection. The end of the lock nut has a radially inwardly extending flange. After the lock nut is connected, the flange presses against the end cap, which in turn presses against the filter screen frame. Because both the external and internal threads have right-angled trapezoidal cross-sections, the creep resistance of the threads is improved.

[0008] The sealing ring is positioned between the outer annular surface of the end cap and the inner annular surface of the housing, employing a radial sealing method. The sealing ring is compressed by the inner surface of the housing, ensuring that the degree of compression is independent of the thread preload. The end cap and locking nut are separate components; the end cap does not participate in locking, and the locking nut only needs to press the end cap to prevent axial movement. This requires minimal preload, thus improving sealing reliability.

[0009] In the aforementioned blood perfusion adsorber, the side of the external thread facing the middle of the housing has a first engagement force-bearing surface, and the intersection line of the cross section passing through the center line of the housing and the first engagement force-bearing surface is perpendicular to the center line of the housing. The internal thread has a second engagement force-bearing surface, and the intersection line of the cross section passing through the center line of the housing and the second engagement force-bearing surface is perpendicular to the center line of the housing. When the threaded connection is made, the first engagement force-bearing surface and the second engagement force-bearing surface engage.

[0010] Because of the presence of a first meshing force-bearing surface and a second meshing force-bearing surface, the force-bearing area between the external thread and the internal thread is increased, the pressure on the external thread and the internal thread is reduced, and the friction is increased, making it less likely for the internal thread and the external thread to loosen.

[0011] In the aforementioned blood perfusion adsorber, the number of engagement turns between the external and internal threads is no less than 5 turns. Increasing the number of thread turns reduces the stress on the external and internal threads under the same preload.

[0012] In the aforementioned blood perfusion adsorber, the thread height of the external thread is greater than or equal to 1.6 mm, and the thread height of the internal thread is greater than or equal to 1.6 mm. By increasing the thread height of the external and internal threads, the force-bearing area is increased, thereby reducing the pressure.

[0013] In the aforementioned blood perfusion adsorber, the wall thickness of the locking nut at the internal thread is greater than or equal to 3.8 mm; the wall thickness of the housing at the external thread is greater than or equal to 3.8 mm. Increasing the wall thickness of the locking nut and housing at the threaded locations makes the threads less prone to deformation.

[0014] In the above-mentioned blood perfusion adsorber, the housing is provided with a first anti-detachment tooth and the locking nut is provided with a second anti-detachment tooth. When the locking nut is tightened, the first anti-detachment tooth abuts against the second anti-detachment tooth to prevent the locking nut from rotating.

[0015] In the above-mentioned blood perfusion adsorber, the first anti-detachment tooth is located on the side of the external thread near the middle of the shell, and the inner side of the locking nut near the middle of the shell is provided with an annular groove. The second anti-detachment tooth is located in the annular groove, and the height of the second anti-detachment tooth along the radial direction of the shell is not higher than the depth of the annular groove.

[0016] The second anti-detachment tooth is positioned within the annular groove, and its depth does not exceed that of the groove. During the connection between the external and internal threads, the second anti-detachment tooth will not affect the external thread. Similarly, since the first anti-detachment tooth is located on the side of the external thread near the center of the housing, it will not affect the internal thread during connection.

[0017] In the above-mentioned blood perfusion adsorber, the first anti-detachment tooth is provided with a first guide slope, which gradually rises along the screwing direction of the locking nut, and the second anti-detachment tooth is provided with a second guide slope, which gradually decreases along the screwing direction of the locking nut.

[0018] The first guide bevel guides the second anti-detachment tooth, allowing the second anti-detachment tooth to pass over the first anti-detachment tooth. When the second anti-detachment tooth completely passes over the first anti-detachment tooth, the locking nut is fully engaged. At this point, the second anti-detachment tooth is limited by the first anti-detachment tooth, preventing the locking nut from rotating.

[0019] Compared with existing technologies, this blood perfusion adsorbent has the following advantages:

[0020] The cross-sections of the external and internal threads are right-angled trapezoids, which can generate greater frictional force under relatively small clamping force, preventing deformation and loosening of the internal and external threads; the increased number of thread engagement turns can distribute the clamping force of the threads, thereby reducing creep deformation; the deeper threads and the wall thickness at the threads can improve the creep resistance of the threads; the sealing ring is clamped by side compression, and when the threads loosen and the end cap is slightly raised, it will not affect the sealing performance; the lock nut is set separately from the end cap, and tightening it will not drive the sealing ring to move, and the threads will not move the sealing ring and end cap when they loosen, making the sealing structure more stable. Attached Figure Description

[0021] Figure 1 This is an axial sectional view of the blood perfusion adsorber provided by this utility model.

[0022] Figure 2 yes Figure 1 Enlarged diagram of point A in the middle.

[0023] Figure 3 This is a radial cross-sectional view of the blood perfusion adsorber provided by this utility model.

[0024] Figure 4 yes Figure 3 Enlarged diagram of point B in the middle.

[0025] In the figure, 1. Shell; 11. Inner annular step; 12. External thread; 121. First engagement force surface; 13. First anti-disengagement tooth; 131. First guide slope; 2. Filter screen frame; 3. End cap; 4. Locking nut; 41. Internal thread; 411. Second engagement force surface; 42. Second anti-disengagement tooth; 421. Second guide slope; 43. Annular groove; 5. Sealing ring. Detailed Implementation

[0026] The following are specific embodiments of the present invention, which are described in conjunction with the accompanying drawings. However, the present invention is not limited to these embodiments.

[0027] like Figure 1 The blood perfusion adsorber shown includes a cylindrical shell 1. The two ends of the shell 1 are respectively provided with a filter screen frame 2, an end cap 3, and a locking nut 4. The structures of the two ends are the same. This embodiment describes one end in detail.

[0028] like Figure 1 and Figure 2 As shown, an inner annular step 11 is provided on the inner side of both ends of the housing 1. The filter screen frame 2 is located inside the housing 1 and abuts against the inner annular step 11. The end cap 3 is located inside the housing 1 and presses against the filter screen frame 2. The locking nut 4 is threaded to the housing 1 and has a radially inwardly extending flange at its end. After the locking nut 4 is connected in place, the flange presses against the end cap 3. To achieve the threaded connection, the locking nut 4 has an internal thread 41, and the housing 1 has an external thread 12. The cross-sections of both the external thread 12 and the internal thread 41 are right-angled trapezoids. To achieve a seal, such as Figure 1 and Figure 2 As shown, a sealing ring 5 is provided between the outer ring surface of the end cap 3 and the inner ring surface of the housing 1.

[0029] The sealing ring 5 is positioned between the outer annular surface of the end cap 3 and the inner annular surface of the housing 1, providing a radial seal. The sealing ring 5 is compressed by the inner surface of the housing 1, ensuring that the degree of compression of the sealing ring 5 is independent of the thread preload. The end cap 3 and the locking nut 4 are separate components. The end cap 3 does not participate in locking; the locking nut 4 only needs to press the end cap 3 to prevent axial movement. This requires less preload, thereby improving the reliability of the seal.

[0030] like Figure 2 As shown, the external thread 12 has a first engagement force-bearing surface 121 on the side facing the middle of the housing 1. The intersection line of the cross section passing through the center line of the housing 1 and the first engagement force-bearing surface 121 is perpendicular to the center line of the housing 1. The internal thread 41 has a second engagement force-bearing surface 411. The intersection line of the cross section passing through the center line of the housing 1 and the second engagement force-bearing surface 411 is perpendicular to the center line of the housing 1. When the threaded connection is made, the first engagement force-bearing surface 121 and the second engagement force-bearing surface 411 engage.

[0031] Because of the presence of a first engagement force-bearing surface 121 and a second engagement force-bearing surface 411, the force-bearing area between the external thread 12 and the internal thread 41 is increased, the pressure on the external thread 12 and the internal thread 41 is reduced, and the friction is increased, making it less likely for the internal thread 41 and the external thread 12 to loosen.

[0032] The number of engagement turns between the external thread 12 and the internal thread 41 is not less than 5. Increasing the number of thread turns reduces the stress on the external thread 12 and internal thread 41 under the same preload. In this embodiment, the thread height of the external thread 12 is greater than or equal to 1.6 mm, and the thread height of the internal thread 41 is greater than or equal to 1.6 mm. Increasing the thread height of the external thread 12 and internal thread 41 increases the stress-bearing area, thereby reducing pressure. The wall thickness of the locking nut 4 at the internal thread 41 is greater than or equal to 3.8 mm; the wall thickness of the housing 1 at the external thread 12 is greater than or equal to 3.8 mm. Increasing the wall thickness of the locking nut 4 and housing 1 at the threads makes the threads less prone to deformation.

[0033] like Figure 3 and Figure 4 As shown, the housing 1 is provided with a first anti-disengagement tooth 13, and the locking nut 4 is provided with a second anti-disengagement tooth 42. When the locking nut 4 is locked, the first anti-disengagement tooth 13 abuts against the second anti-disengagement tooth 42 to prevent the locking nut 4 from rotating.

[0034] Specifically, such as Figure 3 As shown, there are two first anti-detachment teeth 13, which are symmetrically arranged along the central axis of the housing 1, and two second anti-detachment teeth 42, which are symmetrically arranged along the central axis of the locking nut 4.

[0035] To avoid interference, the first anti-disengagement tooth 13 is located on the side of the external thread 12 near the middle of the housing 1, such as... Figure 3 and Figure 4 As shown, the locking nut 4 has an annular groove 43 on the inner side of one end near the middle of the housing 1, and the second anti-disengagement tooth 42 is provided in the annular groove 43. The height of the second anti-disengagement tooth 42 along the radial direction of the housing 1 is not higher than the depth of the annular groove 43.

[0036] The second anti-detachment tooth 42 is disposed within the annular groove 43, and the second anti-detachment tooth 42 is not higher than the depth of the annular groove 43. During the connection between the external thread 12 and the internal thread 41, the second anti-detachment tooth 42 will not affect the external thread 12. Similarly, since the first anti-detachment tooth 13 is located on the side of the external thread 12 near the middle of the housing 1, it will not affect the internal thread 41 during the connection process.

[0037] like Figure 4As shown, the first anti-detachment tooth 13 is provided with a first guide slope 131, which gradually rises along the screwing direction of the locking nut 4. The second anti-detachment tooth 42 is provided with a second guide slope 421, which gradually decreases along the screwing direction of the locking nut 4. The first guide slope 131 guides the second anti-detachment tooth 42, facilitating its passage over the first anti-detachment tooth 13, and the second guide slope 421 guides the first anti-detachment tooth 13, facilitating its passage over the second anti-detachment tooth 42. When the second anti-detachment tooth 42 completely passes over the first anti-detachment tooth 13, the locking nut 4 is just locked. At this time, the second anti-detachment tooth 42 is limited by the first anti-detachment tooth 13, preventing the locking nut 4 from rotating.

[0038] Because the cross-sections of the external thread 12 and the internal thread 41 are right-angled trapezoids, a large frictional force can be obtained under relatively small clamping force, preventing the internal thread 41 and the external thread 12 from deforming and loosening. The number of engagement turns is greater than or equal to 5, which can distribute the clamping force of the thread, thereby reducing creep deformation. Deeper threads and thicker wall thickness at the thread ends improve the thread's creep resistance. The locking nut 4 is separately installed from the end cap 3; tightening it will not cause the sealing ring 5 to move, and loosening the thread will not affect the sealing ring 5 or the end cap 3, making the sealing structure more stable. The sealing ring 5 is clamped by lateral compression; when the thread loosens and the end cap 3 is slightly raised, it will not affect the sealing performance.

[0039] The specific embodiments described herein are merely illustrative examples illustrating the spirit of this utility model. Those skilled in the art to which this utility model pertains may make various modifications or additions to the described specific embodiments or use similar methods to substitute them, without departing from the spirit of this utility model or exceeding the scope defined by the appended claims.

Claims

1. A blood perfusion adsorber, comprising a cylindrical shell (1), characterized in that, The housing (1) is provided with a filter screen frame (2), an end cap (3) and a locking nut (4) at both ends. The filter screen frame (2) is located inside the housing (1) and abuts against the inner annular step (11) of the housing (1). The end cap (3) is located inside the housing (1) and presses on the filter screen frame (2). The locking nut (4) presses on the end cap (3). A sealing ring (5) is provided between the outer annular surface of the end cap (3) and the inner annular surface of the housing (1). The locking nut (4) is provided with an internal thread (41). The housing (1) is provided with an external thread (12). The cross sections of the external thread (12) and the internal thread (41) are both right-angled trapezoids.

2. The blood perfusion adsorber according to claim 1, characterized in that, The housing (1) is provided with a first anti-detachment tooth (13), and the locking nut (4) is provided with a second anti-detachment tooth (42). When the locking nut (4) is locked, the first anti-detachment tooth (13) abuts against the second anti-detachment tooth (42) to prevent the locking nut (4) from rotating.

3. The blood perfusion adsorber according to claim 2, characterized in that, The first anti-detachment tooth (13) is located on the side of the external thread (12) near the middle of the housing (1). The locking nut (4) has an annular groove (43) on the inner side of one end near the middle of the housing (1). The second anti-detachment tooth (42) is located in the annular groove (43). The height of the second anti-detachment tooth (42) along the radial direction of the housing (1) is not higher than the depth of the annular groove (43).

4. The blood perfusion adsorbent according to claim 2 or 3, characterized in that, The first anti-detachment tooth (13) is provided with a first guide slope (131), which gradually rises along the screwing direction of the locking nut (4). The second anti-detachment tooth (42) is provided with a second guide slope (421), which gradually decreases along the screwing direction of the locking nut (4).

5. The blood perfusion adsorber according to claim 1, characterized in that, The external thread (12) has a first engagement force surface (121) on the side facing the middle of the housing (1). The intersection line of the cross section through the center line of the housing (1) and the first engagement force surface (121) is perpendicular to the center line of the housing (1). The internal thread (41) has a second engagement force surface (411). The intersection line of the cross section through the center line of the housing (1) and the second engagement force surface (411) is perpendicular to the center line of the housing (1). When the thread is connected, the first engagement force surface (121) and the second engagement force surface (411) engage.

6. The blood perfusion adsorber according to claim 1, characterized in that, The number of engagement turns between the external thread (12) and the internal thread (41) is not less than 5 turns.

7. The blood perfusion adsorber according to claim 1, characterized in that, The thread height of the external thread (12) is greater than or equal to 1.6 mm, and the thread height of the internal thread (41) is greater than or equal to 1.6 mm.

8. The blood perfusion adsorber according to claim 1, characterized in that, The wall thickness of the locking nut (4) at the internal thread (41) is greater than or equal to 3.8 mm; the wall thickness of the housing (1) at the external thread (12) is greater than or equal to 3.8 mm.

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