A ladder type PTFE seal structure

Abstract

The utility model discloses a ladder type PTFE sealing element structure, including the shell of setting up the pivot piece still including the main seal of setting up in the outer side of pivot piece and the inner ring is provided with the lip, is equipped with the strip hole of symmetrical arrangement on the side wall of main seal, still including the vice seal of sticking to the side wall of main seal, the ring strip of inserting in the strip hole is fixedly installed on the vice seal, is equipped with the air cavity in main seal. The ladder type PTFE sealing element structure provided by the utility model increases the main seal and vice seal connection contact surface and friction force through the ring strip of rubber material quality, makes two not easy to slip off through temperature difference change, reduces the generation of gap, and the air cavity is accompanied by the pressure of cavity edge to strip hole position in the heating process and makes the connection more fastening, simultaneously accompanied by the lip far away from pivot piece side wall far away, the purpose is that the contact surface between rubber deformation and pivot piece can be reduced under high temperature environment, reduces the abrasion of pivot piece to main seal, improves ladder type PTFE sealing element use efficiency.

Description

Technical Field

[0001] This utility model relates to the field of sealing technology, and more specifically to a stepped PTFE sealing structure. Background Technology

[0002] PTFE seals are commonly used in mechanical parts to prevent media leakage. They can be used to seal parts in a stationary state or to provide sliding seals for rotating shafts.

[0003] According to the public announcement number: CN219082245U, the public announcement date: 2023-05-26, a reciprocating sealing ring for one-way holes made of high temperature, high speed and wear-resistant PTFE+B material is disclosed.

[0004] In the prior art, including the aforementioned patents, the stepped PTFE seals used on shafts are mainly composite seal structures. However, the working environment of stepped PTFE seals varies greatly in temperature, and the seals are easily deformed by temperature, which increases the gap between the main and auxiliary seals. As a result, the lubricating oil leaks out from the gap. At the same time, the deformed composite seal also changes the contact surface with the shaft, aggravating the wear at the lip of the stepped PTFE seal and making the seal inefficient. Utility Model Content

[0005] The purpose of this invention is to provide a stepped PTFE sealing structure to solve the problems mentioned above.

[0006] To achieve the above objectives, this utility model provides the following technical solution:

[0007] A stepped PTFE seal structure includes a housing with a rotating shaft and a main seal fitted on the outside of the rotating shaft and having a lip on its inner ring. The main seal has symmetrically arranged slots on its sidewall.

[0008] It also includes a secondary seal that fits against the side wall of the main seal, and a ring strip that is inserted into the strip hole is fixedly installed on the secondary seal;

[0009] The main seal has an air cavity, which deforms and compresses the strip hole to form a cavity edge.

[0010] Preferably, the secondary seal has an annular recess, and the main seal sidewall has a bulge that is embedded in the annular recess.

[0011] Preferably, the cystic protrusion is connected to the air cavity, and the deformed cystic protrusion cooperates with the annular strip.

[0012] Preferably, the main sealing sidewall is provided with a side seal that bulges due to pressure from the cavity edge.

[0013] In the above technical solution, the stepped PTFE sealing structure provided by this utility model has the following beneficial effects: the rubber ring increases the contact surface and friction between the main seal and the secondary seal, making them less prone to slippage under temperature changes, reducing the generation of gaps. During the heating process of the air cavity, the cavity edge is squeezed and bulges, causing the symmetrically arranged cavity edge to apply pressure to the strip hole position. That is, the fitted ring is under pressure, making the connection between the main seal and the secondary seal more secure. At the same time, the lip moves away from the side wall of the rotating shaft, which aims to reduce the deformation of the rubber and the contact surface between it and the rotating shaft in high-temperature environments, reducing the wear caused by the rotating shaft to the main seal. In low-temperature environments, the cavity edge position cannot deform, thus maintaining a constant distance between the fixed lip and the side wall of the rotating shaft, effectively reducing the problem of severe wear of the seal due to temperature changes, and improving the efficiency of the stepped PTFE sealing. Attached Figure Description

[0014] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in this utility model. For those skilled in the art, other drawings can be obtained based on these drawings.

[0015] Figure 1 This is a schematic diagram of the assembly of the rotating shaft and its housing provided in an embodiment of the present utility model;

[0016] Figure 2 This is a side cross-sectional view of the rotating shaft and its housing provided in an embodiment of the present utility model;

[0017] Figure 3 for Figure 2 Enlarged view of point A;

[0018] Figure 4 A side cross-sectional view of the main seal and secondary seal after assembly, provided for an embodiment of this utility model.

[0019] Explanation of reference numerals in the attached figures:

[0020] 1. Outer shell; 2. Rotating shaft; 3. Main seal; 31. Lip; 32. Bar hole; 33. Air chamber; 34. Bulb protrusion; 35. Cavity edge; 36. Side seal; 4. Secondary seal; 41. Ring bar; 42. Ring recess. Detailed Implementation

[0021] To enable those skilled in the art to better understand the technical solution of this utility model, the present utility model will be further described in detail below with reference to the accompanying drawings.

[0022] like Figure 1-4As shown, a stepped PTFE sealing structure includes a housing 1 with a rotating shaft 2, and a main seal 3 sleeved on the outside of the rotating shaft 2 and having a lip 31 on the inner ring. The main seal 3 has symmetrically arranged slots 32 on its sidewall.

[0023] It also includes a secondary seal 4 that fits against the side wall of the main seal 3, and a ring 41 that is inserted into the bar hole 32 is fixedly installed on the secondary seal 4;

[0024] The main seal 3 has an air cavity 33, which deforms and compresses the strip hole 32 to form a cavity edge 35.

[0025] Specifically, the rotation method of the rotating shaft 2 within the housing 1 is existing technology and will not be described in detail here. The lip 31 abuts against the recess on the side wall of the rotating shaft 2, and the contact sealing method is existing technology. Furthermore, the inner wall of the housing 1 is provided with an annular groove for the stable installation of the main seal 3 and the secondary seal 4 (existing technology, which will not be described in detail here).

[0026] Furthermore, the components on the main seal 3 and the secondary seal 4 are all made of rubber. The air cavity 33 is filled with air so that thermal expansion and contraction can be used to cause the air cavity 33 to expand and contract, causing the cavity edge 35 to deform and bulge. The air cavity 33 does not deform because it is too thick towards the lip 31. Therefore, the deformed cavity edge 35 causes the lip 31 to move radially to compensate for the positional change caused by the bulge on both sides.

[0027] Furthermore, the ring bar 41 is in the shape of an annular sheet, and the air cavity 33 is arranged in an annular manner in the main seal 3, so that the heat-receiving area of ​​the air cavity 33 is larger, the heat transfer effect is more obvious, and the reaction capability of the cavity edge 35 is stronger.

[0028] The ring 41 is fitted into the slot 32 by the secondary seal 4 sleeved on the outer wall of the main seal 3. The rubber ring 41 increases the contact surface and friction between the main seal 3 and the secondary seal 4, making them less prone to slippage under temperature changes and reducing gaps. During the heating process, the cavity edge 35 is squeezed and bulges, which puts pressure on the slot 32 position of the symmetrically arranged cavity edge 35. That is, the fitted ring 41 is under pressure, making the connection between the main seal 3 and the secondary seal 4 more secure. At the same time, the lip 31 moves away from the side wall of the rotating shaft 2. The purpose is to reduce the rubber deformation and the contact surface between it and the rotating shaft 2 under high temperature conditions, and reduce the wear of the main seal 3 caused by the rotating shaft 2. Under low temperature conditions, the cavity edge 35 cannot deform, so the fixed lip 31 and the side wall of the rotating shaft 2 are kept constant, which effectively reduces the problem of severe wear of the seal due to temperature changes and improves the efficiency of the stepped PTFE seal.

[0029] As a further embodiment of this utility model, the secondary seal 4 has an annular recess 42, and the main seal 3 has a bulge 34 embedded in the annular recess 42 on its side wall.

[0030] Specifically, the cyst protrusion 34 is a rubber cyst, and in the default state, the cyst protrusion 34 is matched with the annularly arranged recesses 42.

[0031] By using the secondary seal 4 fitted on the outer wall of the main seal 3 and fitted with the bulge 34, the bulge 34 further strengthens the connection area between the two, improves the anti-slip effect, reduces the generation of gaps, and the bulge 34, which is set opposite to the ring bar 41, can form a misaligned connection, improving the connection stability of the stepped PTFE seal.

[0032] As another embodiment further provided in this utility model, the cyst protrusion 34 is connected to the air cavity 33, and the deformed cyst protrusion 34 cooperates with the ring strip 41.

[0033] When the bulging protrusion 34 is filled with pressure from the air chamber 33, the connection between the protrusion 34 and the annular recess 42 becomes tighter. The protrusion 34, which is in a snap-fit ​​state, applies pressure to the secondary seal 4 after being heated, so that the secondary seal 4 is stably fixed in the annular groove on the inner wall of the outer shell 1. At the same time, the pressure is also transmitted to the ring strip 41 through the rubber, so that the ring strip 41 and the strip hole 32 have a more stable fitting effect.

[0034] As another embodiment further provided in this utility model, a side seal 36 is provided on the side wall of the main seal 3, which is raised by the pressure of the cavity edge 35.

[0035] After the force is transmitted to the ring bar 41 through the cavity edge 35, it is then transmitted to the side wall of the main seal 3, causing the side seal 36 to bulge from the side wall of the main seal 3. This allows the symmetrically arranged side seals 36 to individually contact the annular groove on the inner wall of the outer shell 1, further enhancing the anti-slip effect of the main seal 3. At the same time, the side seal 36 also provides the ability to accommodate the lip 31 away from the side wall of the rotating shaft 2, allowing the lip 31 to maintain stable radial movement.

[0036] Working principle: The ring 41 is fitted into the slot 32 by the auxiliary seal 4 sleeved on the outer wall of the main seal 3. The rubber ring 41 increases the contact surface and friction between the main seal 3 and the auxiliary seal 4. During the heating process of the air cavity 33, the cavity edge 35 is squeezed and bulges, so that the symmetrically arranged cavity edge 35 applies pressure to the slot 32. That is, the fitted ring 41 is under pressure, making the connection between the main seal 3 and the auxiliary seal 4 more secure. At the same time, the lip 31 moves away from the side wall of the rotating shaft 2. The purpose is to reduce the deformation of the rubber and the contact surface between it and the rotating shaft 2 under high temperature environment, and reduce the wear of the main seal 3 caused by the rotating shaft 2. Under low temperature environment, the cavity edge 35 cannot deform, so the fixed distance between the lip 31 and the side wall of the rotating shaft 2 remains constant, effectively reducing the problem of severe wear of the seal due to temperature changes.

[0037] The above description only illustrates certain exemplary embodiments of the present invention. Undoubtedly, those skilled in the art can modify the described embodiments in various ways without departing from the spirit and scope of the present invention. Therefore, the above drawings and descriptions are illustrative in nature and should not be construed as limiting the scope of protection of the claims of the present invention.

Claims

1. A stepped PTFE sealing structure, comprising a housing (1) with a rotating shaft (2), characterized in that, It also includes a main seal (3) sleeved on the outside of the rotating shaft (2) and having a lip (31) on the inner ring, wherein the main seal (3) has symmetrically arranged slots (32) on its side wall. It also includes a secondary seal (4) that fits against the side wall of the main seal (3), and a ring (41) that is inserted into the bar hole (32) is fixedly installed on the secondary seal (4). The main seal (3) has an air cavity (33) which deforms and compresses the strip hole (32) to form a cavity edge (35).

2. The stepped PTFE sealing structure according to claim 1, characterized in that, The secondary seal (4) has an annular recess (42), and the main seal (3) has a bulge (34) embedded in the annular recess (42) on its side wall.

3. The stepped PTFE sealing structure according to claim 2, characterized in that, The cyst protrusion (34) is connected to the air cavity (33), and the deformed cyst protrusion (34) cooperates with the ring strip (41).

4. The stepped PTFE sealing structure according to claim 3, characterized in that, The main seal (3) has a side seal (36) that is raised by the pressure of the cavity edge (35) on its side wall.

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