CN111075846A

CN111075846A - Sealing structure capable of isolating bearing wear particles

Info

Publication number: CN111075846A
Application number: CN202010014746.3A
Authority: CN
Inventors: 郑淇文; 陆栋梁; 杨智峻
Original assignee: Fengkai Medical Equipment Shanghai Co ltd
Current assignee: Fengkai Medical Equipment Shanghai Co ltd
Priority date: 2020-01-07
Filing date: 2020-01-07
Publication date: 2020-04-28

Abstract

The invention discloses a sealing structure capable of isolating bearing wear particles, which comprises a rotating shaft and a bearing, wherein one end of the rotating shaft is provided with a near-end sealing cover and a near-end fixing frame, and the other end of the rotating shaft is provided with a far-end sealing cover and a far-end fixing frame; the near end of the rotating shaft is connected with a driving power device; a perfusion inflow annular cavity is formed among the outer edge of the near-end sealing cover, the near-end fixing frame, the far-end fixing frame, the outer edge of the far-end sealing cover and the rotating shaft; and a static sealing cavity is formed among the far-end fixing frame, the inner wall of the far-end sealing cover, the near-end fixing frame and the inner wall of the near-end sealing cover, and the rotating shaft, the bearing and the driving power device are positioned in the static sealing cavity. The invention can ensure that liquid continuously enters from the near end of the bearing and flows out from the far end of the bearing while realizing shaft lubrication and abrasion particle sealing; the high-speed rotating shaft does not generate friction with any part, so that abrasion particles in the sealing part can be isolated, and the particles are prevented from entering a human body to form thrombus.

Description

Sealing structure capable of isolating bearing wear particles

Technical Field

The invention relates to a sealing structure in an interventional medical instrument, in particular to a sealing structure capable of isolating bearing abrasion particles, which is used for realizing that a power source is positioned in an interventional type blood pumping catheter device outside a body and reducing the particles from entering the body.

Background

The common bearing with the sealing cover is mainly used for preventing grease in the bearing from flying out of the bearing during the operation of the bearing; and the flying dust and the dust in the use environment are prevented from entering the bearing, the friction loss is increased, and the service life of the bearing is influenced.

The common waterproof bearing is formed by reforming a common bearing with a sealing cover, a rubber ring is added on the outer edge of the common sealing cover, the gap between the original common sealing cover and the inner ring of the bearing is filled by the rubber ring, but the sealing performance is poor, only splash can be prevented, and long-time liquid scouring cannot be realized.

However, bearing seals can be generally classified as static seals, dynamic seals, pseudo-static seals, and dynamic seals that translate into static seals. Wherein the static seal is a seal with no relative motion between the seal collection surfaces. Dynamic seals are seals in which the sealing elements move relative to one another and are further classified into reciprocating seals, rotary seals and compound-motion seals. The pseudo-static seal is a seal form between the static seal and the dynamic seal, the static seal is seemingly seen, and actually in a micro-motion state, such as a mechanical seal or a secondary seal at a compensating ring in a dry gas seal, which belongs to the seal form.

Patent document CN208535163 discloses a bearing sealing structure, in which a rubber sealing ring is in interference fit with a rotating shaft, and when the rotating shaft rotates at a high speed and stops, the rubber sealing ring performs reciprocating sealing to prevent liquid from entering the bearing. However, the structure of the bearing is soaked in blood, and the structure mentioned in the patent can generate abrasion particles when the rotating shaft and the rubber sealing ring operate, and the particles enter the blood of a human body to form thrombus. In addition, the sealing performance of the structure of the patent is poor, only the splash can be prevented, and the structure cannot bear liquid scouring for a long time without generating abrasion particles.

Patent document CN 109114037 discloses a bearing sealing structure, which prevents liquid from entering through magnet fluid, and has the characteristics of no abrasion, zero leakage, simple structure, long service life and the like. However, the structure of the patent needs a larger space to implement, and the space of the interventional medical device product is smaller, so that the structure cannot be implemented.

Therefore, the bearing sealing structure cannot directly adopt the existing improvement scheme in the field of interventional medical instruments. On one hand, the mature technical scheme in the industrial field needs a larger transmission structure outer diameter (the minimum outer diameter is not less than 10mm), so that the transmission structure cannot be applied to the use scene of the interventional medical instrument. On the other hand, the existing mature technical scheme is more focused on the prior sealing effect, the sealable component can also generate particles when sealing, and thrombus is formed in the body along with the particle entering, so that the use scene of medical instrument intervention cannot be met.

Disclosure of Invention

The invention aims to solve the technical problem of providing a sealing structure capable of isolating bearing abrasion particles, which can continuously provide cooling for a high-speed rotating shaft, reduce the generated abrasion particles and prevent the abrasion particles from entering a patient body, simultaneously prevent human blood from flowing back from a transmission structure, and prevent liquid from continuously washing the transmission structure.

The invention adopts the technical scheme that a sealing structure capable of isolating bearing abrasion particles is provided to solve the technical problems, and the sealing structure comprises a rotating shaft and a bearing, wherein one end of the rotating shaft is provided with a near-end sealing cover and a near-end fixing frame, and the other end of the rotating shaft is provided with a far-end sealing cover and a far-end fixing frame; the near end of the rotating shaft is connected with a rotating element of the driving power device, and an isolation gap is reserved between the rotating shaft and the near end sealing cover as well as between the rotating shaft and the far end sealing cover; a perfusion inflow annular cavity is formed among the outer edge of the near-end sealing cover, the near-end fixing frame, the far-end fixing frame, the outer edge of the far-end sealing cover and the rotating shaft; and static sealing cavities are formed among the far-end fixing frame, the inner wall of the far-end sealing cover, the near-end fixing frame, the inner wall of the near-end sealing cover and the rotating shaft, and the ball of the bearing is positioned in the static sealing cavities.

In the above sealing structure capable of isolating bearing wear particles, the casing of the driving power device is provided with a flowing liquid filling port pipeline and a static liquid filling port pipeline, the flowing liquid filling port pipeline is communicated with the filling inflow annular cavity, and the static liquid filling port pipeline is communicated with the static sealing cavity.

In the sealing structure capable of isolating bearing wear particles, the pipeline of the flowing liquid filling opening is communicated with the filling inflow annular cavity through the metal pipe or the medical hose; the static liquid filling opening pipeline is communicated with the static sealing cavity through a metal pipe or a medical hose.

The sealing structure capable of isolating bearing wear particles is characterized in that the perfusion inflow annular cavity and the static sealing cavity extend into the shell of the driving power device, the rotating element of the driving power device is located in the static sealing cavity, and the perfusion isolation cavity is arranged in the shell of the driving power device.

In the above 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 region, and a triangular dead zone is formed at the isolation gap inside the distal sealing cover.

The sealing structure capable of isolating bearing wear particles is characterized in that the rated rotating speed of the rotating shaft is 40,000RPM, the rotating diameter is 2.0mm, and the isolation gap between the rotating shaft and the distal end sealing cover is 0.2mm-3.0 mm.

Compared with the prior art, the invention has the following beneficial effects: 1. the cooling liquid is provided for the transmission rotating shaft, so that local high temperature is prevented from being generated when the rotating shaft rotates at high speed, and the damage of burning to the body organ of a patient is avoided. 2. Fully keep apart the particulate matter that produces in transmission pivot and the bearing operation process, prevent that the particulate matter from getting into the patient internal, form the thrombus.

Drawings

FIG. 1 is a schematic view of a seal configuration in an embodiment of the present invention;

FIG. 2 is a schematic structural diagram of a rotating shaft with a seal connected to a driving power device in an embodiment of the present invention;

FIG. 3 is a schematic illustration of the turbulence of the perfusate in an embodiment of the present invention.

In the figure:

1 rotating shaft 2 bearing 3 near-end sealing cover

4 distal end seal cover 5 driving power device 6 static seal cavity

7 perfusion inflow ring cavity 8 near end fixing frame 9 far end fixing frame

10 fills isolation chamber 11 flowing liquid and irritates filling opening pipeline 12 stationary liquid and irritates filling opening pipeline

13 impeller 14 annular turbulent vortex region

Detailed Description

The invention is further described below with reference to the figures and examples.

FIG. 1 is a schematic view of a seal configuration in an embodiment of the present invention; fig. 2 is a schematic structural diagram of a rotating shaft with a seal connected with a driving power device in the embodiment of the invention.

Referring to fig. 1 and 2, the sealing structure capable of isolating bearing wear particles according to the present invention includes a rotating shaft 1 and a bearing 2, wherein one end of the rotating shaft 1 is provided with a near-end sealing cover 3 and a near-end fixing frame 8, and the other end is provided with a far-end sealing cover 4 and a far-end fixing frame 9; the far end of the rotating shaft 1 is connected with a driving power device 5.

Wherein the distal end of the shaft 1 is connected to the intended structure and the proximal end is connected to the intended driving power structure, such as the driving power means 5.

Wherein, the sealing structure is composed of a far-end sealing cover 4 and a near-end sealing cover 3. A certain gap is formed between the sealing cover and the rotating shaft 1, so that when the rotating shaft rotates, no abrasion particles are generated between the rotating shaft 1 and the sealing cover.

The far-end fixing frame 9 and the near-end fixing frame 9 are connected with a closed pipeline to contain the rotating shaft 1, the far-end sealing cover 4, the bearing 2, the near-end sealing cover 3 and the perfusate.

Wherein, the whole structure has two perfusates; one is a non-flowing perfusion liquid which is wrapped by a far-end fixing frame 9, a far-end sealing cover 4, a rotating shaft 1, a bearing 2, a near-end sealing cover 3, a driving power structure and the flowing perfusion liquid. The other is flowing perfusate, and the flowing perfusate flows through the outer edge of the near-end sealing cover 1, the near-end fixing frame 1, the far-end fixing frame 1, the outer edge of the far-end sealing cover 4 and the rotating shaft. The flowing perfusate also plays a role in preventing blood from flowing back, and the rotating wear particles are generated by the rotating shaft, the bearing and the driving power structure, are generated in the non-flowing perfusate and do not enter the body of a patient.

Wherein the perfusion inflow ring cavity 7 and the static seal cavity 6 at the proximal end extend directly or through a metal tube or a medical hose into the housing of the driving power device 5, the rotating element of the driving power device 5 is located in the static seal cavity 6, the housing of the driving power device is provided with a perfusion isolation cavity 10 which separates the static seal cavity 6 from the perfusion inflow ring cavity 7, so that the flowing perfusion fluid and the non-flowing perfusion fluid do not have a junction, as shown in fig. 2; the shell of the driving power device 5 is provided with a flowing liquid filling inlet pipeline 11 and a static liquid filling inlet pipeline 12, the flowing liquid filling inlet pipeline 11 is communicated with the filling inflow annular cavity 7, and the static liquid filling inlet pipeline 12 is communicated with the static sealing cavity 6.

When preoperative preparation is carried out, perfusion liquid enters a flowing area (a near-end sealing cover outer edge, a near-end fixing framework, a far-end sealing cover outer edge and a rotating shaft) from a perfusion inlet pipeline under the driving of a perfusion pump, and then enters a non-flowing area (a far-end sealing cover, a rotating shaft, a bearing, a near-end sealing cover and a driving power structure) from the flowing area.

When the perfusion apparatus is used in the operation, after the non-flowing area is filled with the perfusion liquid, the subsequent perfusion liquid does not enter the non-flowing area any more. At the moment, the final infusion volume entering the patient is equal to the pumping-out flow rate of the infusion pump, and the total infusion volume entering the patient can be known by monitoring the pumping-out flow rate of the single infusion pump. Wherein, the perfusate continues to pass through from the leading edge of distal end mount 9, and this moment this structure has been full of the perfusate, makes human blood unable reflux this structure, guarantees that blood corpuscle can not be destroyed.

When the product is in operation, the impeller 13 at the far end rotates to drive the perfusate in the isolation gap between the sealing cover 4 at the far end and the impeller 13 to rotate. When the gap space is sufficient, a circular turbulent vortex region 14 will be formed in the gap under the interaction of centrifugal and perfusion forces. Further, the turbulent vortex forms a triangular dead zone at the flow gap inside the distal sealing cover, and no medium flows or exchanges any more, so that the perfusion fluid in the non-flow area is sealed and isolated, as shown in fig. 3.

The turbulence is locally controllable turbulence induced intentionally, and the turbulence characteristics are controlled by the mutual relation of the clearance between the impeller and the sealing cover, the rated rotating speed and the rotating diameter of the load. When the rated rotating speed is 40,000RPM and the rotating diameter of the load is 2.0mm, the clearance between the load and the distal sealing cover needs to be larger than 0.2mm, and the sealing isolation can be stably realized through turbulent flow. In practical application, the minimum value of the clearance distance is determined by the required realized rated rotating speed and the outer diameter of the rotating part. Further, it can be summarized that the sealing device is determined by the linear velocity of the liquid rotating radially in the region to be sealed. The higher the line speed, the wider the isolation gap is required. Through repeated tests, the recommended value of the clearance is 0.2mm-3.0mm, when the clearance is smaller than the recommended value, turbulence is located outside the clearance, normal filling media are filled in the clearance, the flow velocity is uniformly distributed, and the liquid isolation effect on a non-flowing area is reduced. Further, the gap is preferably 0.3mm to 2.0 mm.

The invention can ensure that liquid continuously enters from the near end of the bearing 2 and flows out from the far end of the bearing 2 while realizing shaft lubrication and abrasion particle sealing; the liquid sealing mode is realized by inducing the flow field dead zone of the local controllable turbulence member, and no friction is generated with any part when the turbulence member rotates at a high speed, so that abrasion particles in a sealing part can be isolated, and the particles are prevented from entering a human body to form thrombus.

Although the present invention has been described with respect to the preferred embodiments, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.

Claims

1. A sealing structure capable of isolating bearing abrasion particles comprises a rotating shaft (1) and a bearing (2), and is characterized in that one end of the rotating shaft (1) is provided with a near-end sealing cover (3) and a near-end fixing frame (8), and the other end of the rotating shaft is provided with a far-end sealing cover (4) and a far-end fixing frame (9); the near end of the rotating shaft (1) is connected with a rotating element of the driving power device (5), and an isolation gap is reserved between the rotating shaft (1) and the near end sealing cover (3) and between the rotating shaft and the far end sealing cover (4);

a perfusion inflow annular cavity (7) is formed among the outer edge of the near-end sealing cover (3), the near-end fixing frame (8), the far-end fixing frame (9), the outer edge of the far-end sealing cover (4) and the rotating shaft (1); and a static sealing cavity (6) is formed among the inner wall of the far-end fixing frame (9), the inner wall of the far-end sealing cover (4), the inner wall of the near-end fixing frame (8), the inner wall of the near-end sealing cover (3) and the rotating shaft (1), and the ball of the bearing (2) is positioned in the static sealing cavity (6).

2. A sealing structure capable of isolating bearing wear particles according to claim 1, wherein the casing of the driving power device (5) is provided with a flowing liquid filling inlet pipeline (11) and a static liquid filling inlet pipeline (12), the flowing liquid filling inlet pipeline (11) is communicated with the filling inflow annular cavity (7), and the static liquid filling inlet pipeline (12) is communicated with the static sealing cavity (6).

3. A sealing structure capable of isolating bearing wear particles according to claim 2, wherein the flowing liquid filling inlet pipeline (11) is communicated with the filling inflow annular cavity (7) through a metal pipe or a medical hose; the static liquid filling opening pipeline (12) is communicated with the static sealing cavity (6) through a metal pipe or a medical hose.

4. A sealing arrangement for isolating bearing wear particles according to claim 2, characterised in that the priming inflow annulus (7) and the stationary seal chamber (6) extend into the housing of the drive power unit (5), the rotating element of the drive power unit (5) being located in the stationary seal chamber (6), and the housing of the drive power unit (5) being provided with a priming isolation chamber (10).

5. A sealing structure for isolating bearing wear particles according to claim 1, characterized in that the isolation gap between the rotating shaft (1) and the distal seal cover (4) constitutes an annular turbulent vortex zone (14) and a triangular dead zone at the isolation gap inside the distal seal cover.

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