A sealing structure capable of isolating bearing wear particles

Abstract

The present invention discloses a sealing structure capable of isolating bearing wear particles, comprising a rotating shaft and a bearing, wherein a proximal sealing cover and a proximal fixing frame are provided at one end of the rotating shaft, and a distal sealing cover and a distal fixing frame are provided at the other end; the proximal end of the rotating shaft is connected to a driving power device; a perfusion inflow annular cavity is formed between the outer edge of the proximal sealing cover, the proximal fixing frame, the distal fixing frame, the outer edge of the distal sealing cover and the rotating shaft; a static sealing cavity is formed between the distal fixing frame, the inner wall of the distal sealing cover, the proximal fixing frame and the inner wall of the proximal sealing cover, and the rotating shaft, the bearing and the driving power device are located in the static sealing cavity. The present invention can achieve shaft lubrication and wear particle sealing while allowing liquid to continuously enter from the proximal end of the bearing and flow out from the distal end of the bearing; it does not generate friction with any parts during high-speed rotation, thereby isolating wear particles in the sealing component and preventing particles from entering the human body and forming blood clots.

Description

Technical Field

[0001] The present invention relates to a sealing structure in an interventional medical device, and in particular to a sealing structure capable of isolating bearing wear particles, which is used to implement an interventional blood pump catheter device with a power source located outside the body, thereby reducing the entry of particles into the body. Background Art

[0002] Ordinary bearings with sealing covers are mainly used to prevent the grease in the bearings from flying out of the bearings during operation; they also prevent flying dust and powder in the operating environment from entering the bearings, increasing friction loss and shortening the life of the bearings.

[0003] Ordinary waterproof bearings are modified from ordinary bearings with sealing covers. Rubber rings are mainly added to the outer edge of the ordinary sealing cover to fill the gap between the original ordinary sealing cover and the inner ring of the bearing. However, the sealing performance is relatively poor and it can only prevent splashing, but not long-term liquid flushing.

[0004] However, bearing seals can generally be divided into static seals, dynamic seals, pseudo-static seals, and dynamic seals converted into static seals. Static seals are seals in which there is no relative motion between the sealing surfaces. Dynamic seals are seals in which there is relative motion between the sealing elements, and are further divided into reciprocating seals, rotary seals, and compound motion seals. Pseudo-static seals are a type of seal between static and dynamic seals. While superficially static, they are actually in a state of micro-motion. Examples include mechanical seals or the secondary seals at the compensating rings in dry gas seals. Furthermore, to completely resolve the dynamic sealing issue, mechanical devices such as canned motor pumps, magnetic drive pumps, and fully enclosed compressors have emerged that convert dynamic seals into static seals.

[0005] Patent document CN208535163 discloses a bearing seal structure that uses a rubber sealing ring to create an interference fit with the shaft. When the shaft rotates at high speed and stops, the rubber sealing ring provides a reciprocating seal, preventing liquid from entering the bearing. However, the bearing structure is immersed in blood. The structure described in this patent generates wear particles between the shaft and the rubber sealing ring during operation. These particles can enter the human bloodstream and form blood clots. Furthermore, the patented structure has poor sealing properties, providing only splash protection and failing to withstand prolonged liquid exposure without generating wear particles.

[0006] Patent document CN 109114037 discloses a bearing seal structure that uses magnetic fluid to prevent liquid ingress. This structure features zero wear, zero leakage, a simple structure, and a long service life. However, this patented structure requires a relatively large space to implement, which is not feasible in the relatively small space of interventional medical devices.

[0007] As can be seen from the above, existing improvement solutions for bearing sealing structures cannot be directly adopted in the field of interventional medical devices. On the one hand, mature technical solutions in the industrial field require a large transmission structure outer diameter (minimum outer diameter of no less than 10mm), which makes them unsuitable for use in interventional medical devices. On the other hand, existing mature technical solutions prioritize sealing effectiveness, but the sealing components also generate particles when they seal, which can form blood clots when they enter the body, making them unsuitable for use in interventional medical devices. Summary of the Invention

[0008] The technical problem to be solved by the present invention is to provide a sealing structure that can isolate bearing wear particles, which can continuously provide cooling to the high-speed rotating shaft while reducing the generated wear particles to prevent them from entering the patient's body, while preventing human blood from flowing back from the transmission structure and preventing liquid from continuously flushing the transmission structure.

[0009] The technical solution adopted by the present invention to solve the above-mentioned technical problems is to provide a sealing structure that can isolate bearing wear particles, including a rotating shaft and a bearing, wherein one end of the rotating shaft is provided with a proximal sealing cover and a proximal fixing frame, and the other end is provided with a distal sealing cover and a distal fixing frame; the proximal end of the rotating shaft is connected to the rotating element of the driving power device, and an isolation gap is left between the rotating shaft and the proximal sealing cover and the distal sealing cover; an infusion flow annular cavity is formed between the outer edge of the proximal sealing cover, the proximal fixing frame, the distal fixing frame, the outer edge of the distal sealing cover and the rotating shaft; a static sealing cavity is formed between the distal fixing frame, the inner wall of the distal sealing cover, the proximal fixing frame, the inner wall of the proximal sealing cover and the rotating shaft, and the balls of the bearing are located in the static sealing cavity.

[0010] The above-mentioned sealing structure that can isolate bearing wear particles, wherein the housing of the driving power device has a flowing liquid inlet pipeline and a static liquid inlet pipeline, the flowing liquid inlet pipeline is connected to the infusion inlet annular cavity, and the static liquid inlet pipeline is connected to the static sealing cavity.

[0011] The above-mentioned sealing structure that can isolate bearing wear particles, wherein the flowing liquid infusion inlet pipeline is connected to the infusion inflow annular cavity through a metal tube or a medical hose; the static liquid infusion inlet pipeline is connected to the static sealing cavity through a metal tube or a medical hose.

[0012] The above-mentioned sealing structure that can isolate bearing wear particles, wherein the perfusion inflow annular cavity and the static sealing cavity extend into the housing of the driving power device, the rotating element of the driving power device is located in the static sealing cavity, and a perfusion isolation cavity is provided in the housing of the driving power device.

[0013] In the above-mentioned sealing structure capable of isolating bearing wear particles, the isolation gap between the rotating shaft and the distal sealing cover forms an annular turbulent vortex zone, and a triangular dead zone is formed at the isolation gap inside the distal sealing cover.

[0014] In the above-mentioned sealing structure capable of isolating bearing wear particles, the rated speed of the rotating shaft is 40,000 RPM, the rotating diameter is 2.0 mm, and the isolation gap between the rotating shaft and the distal sealing cover is 0.2 mm to 3.0 mm.

[0015] Compared to existing technologies, this invention has the following advantages: 1. It provides coolant to the transmission shaft, preventing localized high temperatures from occurring during high-speed rotation, which could cause burns to the patient's organs. 2. It fully isolates particulate matter generated during operation of the transmission shaft and bearings, preventing it from entering the patient's body and forming blood clots. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 Schematic diagram of the sealing structure in an embodiment of the present invention;

[0017] Figure 2 This is a schematic structural diagram of a sealed rotating shaft connected to a driving power device in an embodiment of the present invention;

[0018] Figure 3 Schematic diagram of turbulence formation of the perfusion fluid in an embodiment of the present invention.

[0019] In the picture:

[0020] 1 Shaft 2 Bearing 3 Proximal sealing cap

[0021] 4 Distal sealing cover 5 Driving power unit 6 Static sealing chamber

[0022] 7 Irrigation into the annular cavity 8 Proximal fixation frame 9 Distal fixation frame

[0023] 10 Perfusion isolation chamber 11 Flowing fluid perfusion inlet line 12 Static fluid perfusion inlet line

[0024] 13 Impeller 14 Annular turbulent vortex zone DETAILED DESCRIPTION

[0025] The present invention will be further described below with reference to the accompanying drawings and examples.

[0026] Figure 1 Schematic diagram of the sealing structure in an embodiment of the present invention; Figure 2 This is a schematic structural diagram of a sealed rotating shaft connected to a driving power device in an embodiment of the present invention.

[0027] See Figure 1 and Figure 2The sealing structure for isolating bearing wear particles provided by the present invention includes a rotating shaft 1 and a bearing 2, wherein one end of the rotating shaft 1 is provided with a proximal sealing cover 3 and a proximal fixing frame 8, and the other end is provided with a distal sealing cover 4 and a distal fixing frame 9; the distal end of the rotating shaft 1 is connected to a driving power device 5.

[0028] The distal end of the rotating shaft 1 is connected to the structure to be used, and the proximal end is connected to the driving power structure to be used, such as the driving power device 5 .

[0029] The sealing structure is composed of a distal sealing cover 4 and a proximal sealing cover 3. There is a certain gap between the sealing cover and the rotating shaft 1, so when the rotating shaft rotates, the rotating shaft 1 and the sealing cover will not generate wear particles.

[0030] The distal fixing frame 9 and the proximal fixing frame 8 are connected to a closed pipeline to accommodate the rotating shaft 1, the distal sealing cover 4, the bearing 2, the proximal sealing cover 3 and the perfusion liquid.

[0031] There are two types of perfusate within the entire structure: one is stagnant perfusate, which is enclosed by the distal fixing frame 9, distal sealing cover 4, rotating shaft 1, bearing 2, proximal sealing cover 3, driving power structure, and flowing perfusate. The other is flowing perfusate, which flows through the outer edge of the proximal sealing cover 3, the proximal fixing frame 8, the distal fixing frame 9, the outer edge of the distal sealing cover 4, and the rotating shaft. The flowing perfusate also prevents blood backflow, while rotating wear particles are generated by the rotating shaft, bearings, and driving power structure. They are produced in the stagnant perfusate and do not enter the patient's body.

[0032] The perfusion inflow annular cavity 7 and the static sealing cavity 6 at the proximal end extend directly or through a metal tube or a medical hose to the housing of the driving power device 5. The rotating element of the driving power device 5 is located in the static sealing cavity 6. The housing of the driving power device is provided with a perfusion isolation cavity 10 to separate the static sealing cavity 6 and the perfusion inflow annular cavity 7 so that there is no confluence point between the flowing perfusion liquid and the non-flowing perfusion liquid. Figure 2 As shown; the housing of the driving power device 5 has a flowing liquid inlet pipeline 11 and a static liquid inlet pipeline 12, the flowing liquid inlet pipeline 11 is connected to the infusion inlet annular cavity 7, and the static liquid inlet pipeline 12 is connected to the static sealing cavity 6.

[0033] During preoperative preparation, the perfusion fluid, driven by the perfusion pump, enters the flow area (outer edge of the proximal sealing cover, proximal fixed structure, distal fixed structure, outer edge of the distal sealing cover and rotating shaft) through the perfusion inlet pipeline, and then enters the non-flow area (distal sealing cover, rotating shaft, bearing, proximal sealing cover and driving power structure) from the flow area.

[0034] During intraoperative use, once the stagnant area is filled with perfusate, subsequent perfusate no longer enters the stagnant area. At this point, the perfusate volume ultimately entering the patient's body is equal to the perfusate pump's output flow rate. Monitoring the output flow rate of a single perfusate pump provides an understanding of the total perfusate volume entering the patient's body. Perfusate continuously flows through the leading edge of the distal fixture 9, which is now filled with perfusate, preventing blood from flowing back into the structure, thus protecting blood cells from damage.

[0035] When the product is running, the impeller 13 at the distal end rotates, driving the perfusate in the isolation gap between the distal sealing cover 4 and the impeller 13 to rotate. When the gap space is sufficient, the interaction between centrifugal and perfusion forces will form an annular turbulent vortex zone 14 in the gap. Furthermore, the turbulent vortex will form a triangular dead zone in the flow gap inside the distal sealing cover, where no medium flows or exchanges, thereby achieving a sealed isolation of the perfusate in the non-flowing area, such as Figure 3 shown.

[0036] The turbulence is intentionally induced local controllable turbulence, and the turbulence characteristics are controlled by the relationship between the gap between the impeller and the sealing cover, the rated speed and the rotational diameter of the load. When the rated speed is 40,000RPM and the load rotational diameter is 2.0mm, the gap between the load and the distal sealing cover must be greater than 0.2mm to achieve stable sealing isolation through turbulence. In practical applications, the minimum value of the gap distance is determined by the required rated speed and the outer diameter of the rotating component. Further, it can be summarized as being determined by the linear velocity of the radial rotation of the liquid in the area to be sealed. The greater the linear velocity, the wider the isolation gap is required. After repeated tests, the recommended gap value is 0.2mm-3.0mm. When the aforementioned gap is less than the recommended value, the turbulence is located outside the gap, the gap is filled with normal medium and the flow rate is evenly distributed, and the liquid isolation effect on the non-flowing area is reduced. Furthermore, the preferred gap is 0.3mm-2.0mm.

[0037] The present invention can achieve shaft lubrication and wear particle sealing while allowing liquid to continuously enter from the proximal end of the bearing 2 and flow out from the distal end of the bearing 2; by inducing a dead zone in the flow field of a local controllable turbulent component to perform liquid sealing, no friction is generated with any parts during high-speed rotation, thereby isolating the wear particles in the sealing component and preventing the particles from entering the human body and forming blood clots.

[0038] Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art may make some modifications and improvements without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention shall be based on the definition of the claims.

Claims

1. A sealing structure capable of isolating bearing wear particles, comprising a rotating shaft (1) and a bearing (2), characterized in that: One end of the rotating shaft (1) is provided with a proximal sealing cover (3) and a proximal fixing frame (8), and the other end is provided with a distal sealing cover (4) and a distal fixing frame (9); the proximal end of the rotating shaft (1) is connected to the rotating element of the driving power device (5), and an isolation gap is left between the rotating shaft (1) and the proximal sealing cover (3) and the distal sealing cover (4); An infusion inflow annular cavity (7) is formed between the outer edge of the proximal sealing cover (3), the proximal fixing frame (8), the distal fixing frame (9), the outer edge of the distal sealing cover (4) and the rotating shaft (1); a static sealing cavity (6) is formed between the distal fixing frame (9), the inner wall of the distal sealing cover (4), the proximal fixing frame (8), the inner wall of the proximal sealing cover (3) and the rotating shaft (1), and the ball of the bearing (2) is located in the static sealing cavity (6); When the product is in operation, the isolation gap between the rotating shaft (1) and the distal sealing cover (4) forms an annular turbulent vortex zone (14), and a triangular dead zone is formed at the isolation gap inside the distal sealing cover.

2. The sealing structure capable of isolating bearing wear particles according to claim 1, characterized in that: The housing of the driving power device (5) is provided with a flowing liquid inlet pipeline (11) and a static liquid inlet pipeline (12); the flowing liquid inlet pipeline (11) is connected to the inlet ring cavity (7); and the static liquid inlet pipeline (12) is connected to the static sealing cavity (6).

3. The sealing structure capable of isolating bearing wear particles according to claim 2, characterized in that: The flowing liquid perfusion inlet pipeline (11) is connected to the perfusion inflow annular cavity (7) via a metal tube or a medical hose; the static liquid perfusion inlet pipeline (12) is connected to the static sealing cavity (6) via a metal tube or a medical hose.

4. The sealing structure capable of isolating bearing wear particles according to claim 2, wherein: The perfusion inflow annular cavity (7) and the static sealing cavity (6) extend into the housing of the driving power device (5), the rotating element of the driving power device (5) is located in the static sealing cavity (6), and a perfusion isolation cavity (10) is provided in the housing of the driving power device (5).

5. The sealing structure capable of isolating bearing wear particles according to claim 1, wherein: The rated speed of the rotating shaft (1) is 40,000 RPM, the rotating diameter is 2.0 mm, and the isolation gap between the rotating shaft (1) and the distal sealing cover (4) is 0.2 mm to 3.0 mm.

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