CN215891502U

CN215891502U - Composite gasket

Info

Publication number: CN215891502U
Application number: CN202121771521.9U
Authority: CN
Inventors: 孙云军; 岑国锋
Original assignee: Ningbo Xinrun Sealing Technology Co ltd
Current assignee: Ningbo Xinrun Sealing Technology Co ltd
Priority date: 2021-07-30
Filing date: 2021-07-30
Publication date: 2022-02-22
Anticipated expiration: 2031-07-30

Abstract

The utility model relates to a composite gasket, which comprises a flexible substrate which is provided with a central hole and is annular, and is characterized in that: the area of the flexible substrate adjacent to the central hole is provided with a polytetrafluoroethylene layer coated on the outer surface of the flexible substrate, and the polytetrafluoroethylene layer is in a wave shape, compared with the prior art, the utility model has the advantages that: the composite gasket is provided with the polytetrafluoroethylene layer coated on the outer surface of the composite gasket in the area adjacent to the central hole, namely the effective sealing part, and the polytetrafluoroethylene layer is corrugated, so that when the composite gasket is in contact with the surface of a flange, the flexible matrix in the composite gasket can be highly compressed and is surrounded in an annular closed space formed between the corrugated polytetrafluoroethylene layer and the flange surface, therefore, the composite gasket has particularly excellent sealing property and resilience, the strength of the composite gasket is increased by the corrugated polytetrafluoroethylene layer, the adverse effect caused by accidental falling of the flexible matrix in the installation or use process of the composite gasket is prevented, and the safety and reliability are improved.

Description

Composite gasket

Technical Field

The utility model relates to the field of sealing gasket processing, in particular to a composite gasket.

Background

The water cavity sealing system of the air cooler product is a system formed by a sealing gasket, a fastener, an end cover flange and the like, and the main failure mode of the system is leakage which is related to a plurality of factors such as the type of a sealing structure, the rigidity of a connected piece, the performance of the sealing gasket, the operation, the installation and the matching. The choice, design and evaluation of gaskets as the primary elements of flange connections is critical to ensure the quality of the seal of the system described above.

At present, gaskets of a water cavity sealing system of an air cooler product are all sealed by adopting non-metal planes, and the adopted materials are non-asbestos fiber rubber plates, polytetrafluoroethylene, asbestos rubber plates and rubber. Non-metallic gaskets of a single material composition have a number of disadvantages:

the problems of the non-asbestos fiber rubber gasket are that: the non-asbestos fiber rubber gasket material is added with rubber and a plurality of fillers, but still has trace permeation, so that the pressure and the temperature are limited, when the gasket material is used for a plurality of high-temperature media, generally in the later period of use, because the rubber and the fillers are carbonized, the strength is reduced, the material becomes loose, the sealing failure is caused, the permeation is generated in the interface and the gasket, the coking and fuming phenomena are generated, in addition, the gasket is easy to be bonded on the sealing surface of the flange at high temperature, and a plurality of troubles are brought to the replacement of the gasket;

if the problem that the rubber gasket exists is simply adopted: the rubber sheet material used as the flange gasket has the pressure not greater than 1.568MPa and the temperature less than 200C, however, the rubber gasket is soft and good in bonding performance, and can exert the sealing effect under smaller pretightening force. Therefore, when the gasket bears internal pressure, the gasket is easily extruded and damaged due to thicker gasket or lower hardness, and sealing failure is caused;

if the polytetrafluoroethylene gasket is adopted, the problems are as follows: although the polytetrafluoroethylene has quite high chemical stability, no toxicity, no pollution and low permeability, and is suitable for sealing surfaces with various complex shapes. However, the gasket is easy to generate cold flow phenomenon, has poor rebound resilience and low bending and compression strength, and is easy to deform under the action of continuous load to directly influence the sealing capability of a joint surface and the service life of the gasket.

SUMMERY OF THE UTILITY MODEL

The present invention is directed to provide a composite gasket with good chemical stability, elasticity and sealing performance in view of the above-mentioned current state of the art.

The technical scheme adopted by the utility model for solving the technical problems is as follows: the composite gasket comprises a flexible substrate which is provided with a central hole and is annular, and is characterized in that: the flexible substrate is provided with a polytetrafluoroethylene layer coated on the outer surface of the flexible substrate in the area adjacent to the central hole, and the polytetrafluoroethylene layer is in a wave shape.

In order to retain the high elasticity of the flexible matrix and have the metal strength, preferably, a metal ring is arranged in the flexible matrix.

Furthermore, the metal ring comprises a first metal corrugated plate and a second metal corrugated plate which are vertically involutory and are arranged in a stacked mode. Because first corrugated metal plate and second corrugated metal plate are range upon range of each other from top to bottom and can realize the effect of self-tightening to utilize flexible base member to compensate external pressure, when producing alternating load because external pressure and temperature take place cyclic variation, the load can be distributed better at whole ripple face, has improved composite seal gasket's fatigue resistance.

Furthermore, the crest parts on the first corrugated metal plates are matched with the trough parts on the second corrugated metal plates in a laminating and fixedly connected mode. Because the crest part and the trough part are fixedly connected in a laminated way, the central strength of the flexible matrix in the flexible matrix can be enhanced as much as possible, and the leakage is slowed down or even eliminated.

In order to improve the sealing performance of the composite gasket, preferably, the outermost periphery of the flexible substrate further has flow-resisting protrusions protruding from the upper and lower surfaces of the flexible substrate.

Preferably, the flexible substrate is made of flexible graphite, mica or rubber.

Compared with the prior art, the utility model has the advantages that: the composite gasket is provided with the polytetrafluoroethylene layer coated on the outer surface of the composite gasket in the area adjacent to the central hole, namely the effective sealing part, and the polytetrafluoroethylene layer is corrugated, so that when the composite gasket is in contact with the surface of a flange, the flexible matrix in the composite gasket can be highly compressed and is surrounded in an annular closed space formed between the corrugated polytetrafluoroethylene layer and the flange surface, therefore, the composite gasket has particularly excellent sealing property and resilience, the strength of the composite gasket is increased by the corrugated polytetrafluoroethylene layer, the adverse effect caused by accidental falling of the flexible matrix in the installation or use process of the composite gasket is prevented, and the safety and reliability are improved.

Drawings

FIG. 1 is a schematic structural diagram of a composite shim in an embodiment of the present invention;

FIG. 2 is a cross-sectional view taken along line A-A of FIG. 1.

Detailed Description

The utility model is described in further detail below with reference to the accompanying examples.

As shown in FIGS. 1-2, the preferred embodiment of the present invention is shown. The composite gasket of the embodiment comprises a flexible substrate 1 which is provided with a central hole 11 and is annular, wherein a polytetrafluoroethylene layer 2 coated on the outer surface of the flexible substrate 1 is arranged in the area adjacent to the central hole 11, the polytetrafluoroethylene layer 2 is in a wave shape, the composite gasket is provided with a polytetrafluoroethylene layer 2 coated on the outer surface of the composite gasket in the area adjacent to the central hole 11, namely the effective sealing part, and meanwhile, the polytetrafluoroethylene layer 2 is in a wave shape, when contacting with the flange surface, the flexible substrate 1 inside can be highly compressed and enclosed in the annular closed space formed between the wave-shaped polytetrafluoroethylene layer 2 and the flange surface, thereby having particularly excellent sealing performance and rebound resilience, the strength of the gasket is improved by the wave-shaped polytetrafluoroethylene layer 2, adverse effects caused by accidental falling of the flexible substrate in the installation or use process of the gasket are prevented, and the safety and the reliability are improved.

Specifically, in order to maintain the high elasticity of the flexible substrate 1 and have the metal strength, the metal ring 3 is arranged in the flexible substrate 1 of the present embodiment, wherein the metal ring 3 comprises a first metal corrugated plate 31 and a second metal corrugated plate 32 which are vertically folded and stacked, a self-tightening effect can be realized due to the fact that the first metal corrugated plate 31 and the second metal corrugated plate 32 are vertically stacked, and the flexible substrate 1 is used for compensating the external pressure, when an alternating load is generated due to the cyclic change of the external pressure and the temperature, the load can be well distributed on the whole corrugated surface, and the fatigue resistance of the composite sealing gasket is improved. The crest portions of the first corrugated metal plate 31 and the trough portions of the second corrugated metal plate 32 are matched, stacked and fixedly connected, and the crest portions and the trough portions are stacked and fixedly connected, so that the central strength of the flexible substrate 1 inside the flexible substrate can be enhanced as much as possible, and leakage can be slowed down or even eliminated.

Claims

1. A composite gasket comprising a flexible substrate (1) having a central hole (11) and being annular, characterized in that: the flexible substrate (1) is provided with a polytetrafluoroethylene layer (2) coated on the outer surface of the flexible substrate in the area adjacent to the central hole (11), and the polytetrafluoroethylene layer (2) is in a wave shape.

2. The composite gasket of claim 1, wherein: a metal ring (3) is arranged in the flexible substrate (1).

3. The composite gasket of claim 2, wherein: the metal ring (3) comprises a first metal corrugated plate (31) and a second metal corrugated plate (32) which are vertically involutory and stacked.

4. The composite gasket of claim 3, wherein: the crest parts of the first corrugated metal plates (31) are matched with the trough parts of the second corrugated metal plates (32) in a laminated and fixedly connected mode.

5. The composite gasket of any one of claims 1 to 4, wherein: the outermost periphery of the flexible substrate (1) is also provided with flow resisting bulges (4) protruding out of the upper surface and the lower surface of the flexible substrate (1).