CN211525774U - Self-tightening type composite sealing structure - Google Patents
Self-tightening type composite sealing structure Download PDFInfo
- Publication number
- CN211525774U CN211525774U CN201921359523.XU CN201921359523U CN211525774U CN 211525774 U CN211525774 U CN 211525774U CN 201921359523 U CN201921359523 U CN 201921359523U CN 211525774 U CN211525774 U CN 211525774U
- Authority
- CN
- China
- Prior art keywords
- sealing
- self
- metal
- seal
- tightening
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Images
Landscapes
- Gasket Seals (AREA)
Abstract
The utility model relates to a from compact form composite seal structure belongs to the integrated configuration that adopts deformation high temperature alloy steel material base member, non-metallic compensation layer of surface coating. The sealing structure belongs to self-tightening sealing and has two sealing points, so that the sealing reliability in low medium pressure is ensured, the leakage rate is unchanged when the medium pressure is improved, the requirement of high and low temperature extreme working environment temperature can be met, reliable sealing in the range of 35K-1000K is realized, and the sealing performance is greatly improved compared with the traditional forced sealing.
Description
Technical Field
The utility model relates to a multistage self-clinching formula composite seal structure of ultra-low temperature high pressure is applicable to cryogenic liquid rocket engine, belongs to space flight technical field.
Background
The sealing problem of the low-temperature liquid rocket engine is long-standing, the development of the low-temperature sealing technology is closely connected with the development of the low-temperature liquid rocket engine, and the low-temperature sealing technology is synchronously developed along with the improvement of the technical level of the engine. In the process of developing low-temperature engines developed in China, the low-temperature sealing technology is always focused on. Up to now, the main sealing structure form is a flange tongue-and-groove type sealing gasket structure, which is detailed in high-pressure afterburning liquid oxygen kerosene engine (Shanghai-Guitian national defense industry publishing Co.), the sealing structure adopts a traditional sealing mechanism, and pre-compression is generated on a sealing gasket by pre-tightening a connecting part during installation to form initial sealing, in the working process, the medium separating force and other external loads weaken the connecting effect, the specific sealing pressure is reduced, but the sealing requirement can still be met under the condition of low working pressure of the current engine. By adopting the sealing mode, the required pre-tightening load is larger, and the load born by the connecting bolt and the flange in the loading process is larger. In order to improve and optimize the sealing structure, a rocket engine designer develops structures such as a conical sealing gasket and an O-shaped sealing ring in sequence, but the rocket engine is difficult to popularize due to the defects of the product and the limitation of the size of the structure. So far, the sealing form taking the flat gasket as the main body can still meet the requirements of the in-service engine.
The international advanced aerospace major countries such as russia, usa, etc have long replaced flat gasket structures with self-tightening sealing structures. In the RD-120, RD-0120 engine, we have seen that, in order to improve the sealing effect and reduce the structural weight of the connection parts, the flange connection is converted into a threaded and welded structure, and the flange sealing is replaced by a threaded ferrule seal of a self-tightening seal having a double seal function. In engines such as SSME, RS-68 and J-2X of oxyhydrogen rocket engines in the United states, self-tightening flange sealing structures are adopted, and the sealing structures form commercial standards and can be purchased as standard parts in a customized mode. However, due to technical blockages, domestic self-tightening sealing has not been explored, but has little substantial progress.
SUMMERY OF THE UTILITY MODEL
The technical solution problem of the utility model is that: the defects of the prior art are overcome, the multistage self-tightening type composite sealing structure suitable for the liquid rocket engine is provided, and the leakage rate requirement of the whole engine system can be met.
The technical solution of the utility model is that: a self-tightening type composite sealing structure comprises a metal sealing base body and an auxiliary sealing layer, wherein the metal sealing base body is composed of a metal sealing ring, an upper sealing ring and a lower sealing ring, the upper sealing ring extends obliquely upwards from the middle part of the inner side of the metal sealing ring, and the lower sealing ring extends obliquely downwards, so that the circumferential section of the metal sealing base body is of a pi-shaped elastic structure; the axial section of the metal sealing ring is wavy, and the auxiliary sealing layer is paved and fixed on the axial section of the metal sealing ring; the self-tightening type composite sealing structure is assembled in a sealing surface formed by a flange component on a sealed medium pipeline; during initial installation, the positions, farthest from the metal sealing ring, of the axial outer sides of the upper sealing ring and the lower sealing ring are respectively used as an upper sealing lip and a lower sealing lip to be in elastic contact with the axial surface of the flange assembly to form first sealing; when the flange assembly is fastened, the self-tightening type composite sealing structure reaches a pre-tightening state, and the auxiliary sealing layer is in contact with the axial surface of the flange assembly to form a second seal; after the internal medium acts on the self-tightening type composite sealing structure, the upper sealing ring and the lower sealing ring expand radially, the first sealing specific pressure is increased, and the metal sealing structure is self-tightening.
The metal sealing substrate is made of metal with yield strength more than or equal to 750 MPa.
The self-tightening composite sealing structure further comprises a compensation layer and an auxiliary sealing layer, wherein the compensation layer covers the outer surface of the metal sealing base body.
The compensation layer is a metal layer plated on the outer surface of the metal sealing base body.
The auxiliary sealing layer is a non-metal layer coated on the outer surface of the metal sealing substrate.
The ratio of the distance between the upper sealing lip and the lower sealing lip to the axial thickness of the metal sealing ring is 1.15-1.4.
The opening angle formed by the upper sealing ring and the lower sealing ring is 10-20 degrees.
The upper sealing lip and the lower sealing lip are annular rings protruding along the axial direction, and the circumferential sections of the annular rings are fan-shaped.
The radius of the fan shape is 0.5-1.5 mm.
The thickness of the compensation layer is 15-40 mu m.
The auxiliary sealing layer 8 is made of flexible graphite material;
the thickness of the auxiliary sealing layer 8 is 0.5-2 mm.
The upper side and the lower side of the metal sealing substrate shaft are provided with tooth-shaped structures.
The tooth-shaped structure is a sawtooth shape with the tooth-shaped height of 0.5mm-2mm, and the number of the sawteeth is at least 5.
Compared with the prior art, the utility model beneficial effect be:
(1) the metal sealing base body of the utility model improves the reliability of the sealing structure step by step in the initial state and the working state through two sealing structures;
(2) the utility model covers the compensation layer on the metal sealing base body, which plays the role of compensating the surface defect and improving the sealing reliability;
(3) the utility model covers the auxiliary sealing layer on the metal sealing base body to play the role of providing an axial forced sealing point;
(4) the utility model belongs to a self-tightening sealing ring, and tests prove that the leakage rate of the sealing ring is not reduced along with the increase of the medium pressure, and the leakage rate is basically stable;
(5) the metal sealing ring of the utility model has the characteristics of low assembly torque and thin flange thickness;
drawings
Fig. 1 is the utility model provides an installation schematic diagram of self-tightening type composite seal structure suitable for cryogenic liquid rocket engine.
In the figure: 1. an upper flange; 2. a lower flange; 3. a seal ring; 4. a connecting bolt; 5. and a hexagonal nut.
Fig. 2 is the patent of the utility model provides a be applicable to the cross-sectional structure sketch map of self-tightening formula composite seal structure of cryogenic liquid rocket engine.
In the figure: 6. a metal sealing substrate; 7. a plating or coating layer; 8. and (4) auxiliary sealing layer.
Detailed Description
The present invention will be described in further detail with reference to the accompanying drawings and specific embodiments.
As shown in fig. 1, the utility model provides a multistage self-tightening composite sealing structure, which is characterized in that the structure comprises a metal sealing base body 6, a plating layer or coating layer 7 and an auxiliary sealing layer 8, wherein the metal sealing base body 6 consists of a metal sealing ring, an upper sealing ring extending obliquely upwards from the middle part of the inner side of the metal sealing ring and a lower sealing ring extending obliquely downwards, so that the circumferential section of the metal sealing base body 6 is of a pi-shaped elastic structure; the axial section of the metal sealing ring is wavy, and an auxiliary sealing layer 8 is paved and fixed on the axial section of the metal sealing ring; the metal sealing base body 6 is assembled in a sealing groove formed by a flange component on a sealed medium pipeline, the flange component specifically comprises an upper flange 1 and a lower flange 2, the upper flange 1 and the lower flange 2 are both provided with step-shaped grooves, the upper flange 1 and the lower flange 2 are connected in a matched mode, an annular groove is formed inside the upper flange 1, and the two sides of the upper flange 1 and the two sides of the lower flange 2 are fastened through a connecting bolt 4 and a hexagonal nut 5. During initial installation, the positions, farthest from the metal sealing ring, of the axial outer sides of the upper sealing ring and the lower sealing ring are respectively used as an upper sealing lip and a lower sealing lip to be in elastic contact with the axial surface of the flange assembly to form first sealing; when the flange assembly is fastened, the self-tightening type composite sealing structure reaches a pre-tightening state, and the auxiliary sealing layer is in contact with the axial surface of the flange assembly to form a second seal; after the internal medium acts on the self-tightening type composite sealing structure, the upper sealing ring and the lower sealing ring expand radially, the first sealing specific pressure is increased, and the metal sealing structure is self-tightening.
In order to ensure the strength and provide enough specific sealing pressure, the metal sealing base body is made of metal with the yield strength of 750MPa or more, deformed high-temperature alloy steel (such as GH625, GH37, GH99 and the like) can be selected, the metal sealing ring, the upper sealing ring and the lower sealing ring are integrally designed and are machined, and the specific design size is generally determined by the use environment.
As a further preferable scheme, as shown in fig. 2, the multi-stage self-tightening composite sealing structure further includes a compensation layer covering an outer surface of the metal sealing substrate, and the compensation layer is used for compensating surface defects and improving sealing reliability. The compensation layer may be a metal layer plated on an outer surface of the metal sealing substrate. The plating layer is made of metal materials (such as silver, copper, nickel and the like) which have good ductility and low strength (the yield strength is less than or equal to 100MPa, and the elongation is more than or equal to 50%) and are compatible with the medium.
In order to provide the second axial forced sealing, the multi-stage self-tightening composite sealing structure further comprises an auxiliary sealing layer, and the auxiliary sealing layer covers the zigzag positions of the outer surface of the auxiliary layer. The auxiliary sealing layer can be made of flexible graphite material.
In order to provide enough specific sealing pressure and ensure good fit of the sealing surface, the ratio of the distance between the upper sealing lip and the lower sealing lip to the axial thickness of the metal sealing ring is 1.15-1.4. In one embodiment of the present invention, the axial distance between the second seal and the first seal lip is 0.2-1mm, which is determined by the design condition and the sealing medium.
In order to provide enough specific sealing pressure and ensure enough compression of the sealing ring base body, the opening angle formed by the upper sealing ring and the lower sealing ring is 10 degrees-20 degrees.
In order to ensure that the sealing ring substrate has enough strength and meet the requirement of repeated use, the middle part of the sealing ring substrate is an arc, the radius range of the arc is 0.5mm-2mm, and the sealing ring substrate is determined by a processing technology.
In order to ensure that the sealing lip of the sealing ring can be well matched with the sealing surface of the flange and adapt to certain assembly errors, the upper sealing lip and the lower sealing lip are annular rings protruding along the axial direction, and the circumferential sections of the upper sealing lip and the lower sealing lip are fan-shaped.
The radius of the fan is 0.5-1.5mm, and the radius of the fan is determined by the design working condition and the sealing medium.
In order to compensate the defects of the sealing surface and improve the sealing reliability, the thickness of the compensation layer is 15-40 mu m, which is determined by the processing technology and the surface roughness of the substrate.
In order to improve the sealing specific pressure of the second seal and improve the sealing reliability, the upper side and the lower side of the metal sealing base body in the axial direction are provided with tooth-shaped structures, the tooth-shaped structures can play a role in fixing the auxiliary sealing layer, and meanwhile, the tooth-shaped structures can improve the contact pressure after contacting with the flange and reduce the leakage of a medium. The tooth-shaped structure is a sawtooth shape with the tooth-shaped height of 0.5mm-2mm, and the number of the sawteeth is at least 5.
The utility model provides a multistage self-tightening formula composite seal structure's theory of operation is: the self-tightening type composite sealing structure comprises a metal sealing base body and an auxiliary sealing layer, wherein the metal sealing base body and the auxiliary sealing layer are arranged on the metal sealing base body, the metal sealing base body is composed of a metal sealing ring, an upper sealing ring and a lower sealing ring, the upper sealing ring extends obliquely upwards from the middle part of the inner side of the metal sealing ring, and the lower sealing ring extends obliquely downwards, so that the circumferential section of the metal sealing base body is of a phi-shaped elastic structure; the axial section of the metal sealing ring is wavy, and the auxiliary sealing layer is paved and fixed on the axial section of the metal sealing ring; the self-tightening type composite sealing structure is assembled in a sealing surface formed by a flange component on a sealed medium pipeline; during initial installation, the positions, farthest from the metal sealing ring, of the axial outer sides of the upper sealing ring and the lower sealing ring are respectively used as an upper sealing lip and a lower sealing lip to be in elastic contact with the axial surface of the flange assembly to form first sealing; when the flange assembly is fastened, the self-tightening type composite sealing structure reaches a pre-tightening state, and the auxiliary sealing layer is in contact with the axial surface of the flange assembly to form a second seal; after the internal medium acts on the self-tightening type composite sealing structure, the upper sealing ring and the lower sealing ring expand radially, the first sealing specific pressure is increased, and the metal sealing structure is self-tightening.
Example (b):
the utility model discloses a multistage self-tightening type composite sealing structure suitable for low-temperature liquid rocket engine, which adopts deformed high-temperature alloy goldThe sealing substrate, the soft metal (copper or silver and the like) plating layer 7 and the auxiliary sealing layer made of non-metal materials (Teflon, F4 and the like). Can meet the requirements of ultralow temperature extreme working environment temperature, meet the compatibility of special media (such as hydrogen, oxygen, fuel gas and the like), and realize the vacuum helium leakage rate of not higher than 1x10 under the pressure of normal temperature and 1MPa-9Pa.m3The vacuum helium leakage rate at normal temperature and low temperature under 40MPa is not higher than 1x10-7Pa.m3This specification is improved by a factor of 100 compared to conventional positive sealing. In addition, the sealing structure can be recycled and reused for 10 times without decomposition (including pressure of 40MPa and ultralow temperature circulation at most). Compared with the traditional bolt pretightening force required by forcibly sealing the sealing ring under the same condition, the bolt pretightening force is reduced by 42 percent, the thickness of the flange is reduced by about 40 percent, and the assembly difficulty and the structure quality are greatly reduced.
Parts of the specification which are not described in detail are within the common general knowledge of a person skilled in the art.
Claims (14)
1. A self-tightening type composite sealing structure is characterized by comprising a metal sealing base body and an auxiliary sealing layer, wherein the metal sealing base body is composed of a metal sealing ring, an upper sealing ring and a lower sealing ring, the upper sealing ring extends obliquely upwards from the middle part of the inner side of the metal sealing ring, and the lower sealing ring extends obliquely downwards, so that the circumferential section of the metal sealing base body is of a phi-shaped elastic structure; the axial section of the metal sealing ring is wavy, and the auxiliary sealing layer is paved and fixed on the axial section of the metal sealing ring; the self-tightening type composite sealing structure is assembled in a sealing surface formed by a flange component on a sealed medium pipeline; during initial installation, the positions, farthest from the metal sealing ring, of the axial outer sides of the upper sealing ring and the lower sealing ring are respectively used as an upper sealing lip and a lower sealing lip to be in elastic contact with the axial surface of the flange assembly to form first sealing; when the flange assembly is fastened, the self-tightening type composite sealing structure reaches a pre-tightening state, and the auxiliary sealing layer is in contact with the axial surface of the flange assembly to form a second seal; after the internal medium acts on the self-tightening type composite sealing structure, the upper sealing ring and the lower sealing ring expand radially, the first sealing specific pressure is increased, and the metal sealing structure is self-tightening.
2. The self-tightening composite seal structure according to claim 1, wherein the metal seal base is made of a metal having a yield strength of 750MPa or greater.
3. The self-clinching composite seal structure of claim 1, further including a compensation layer and an auxiliary seal layer, said compensation layer overlying the outer surface of the metal seal substrate.
4. A self-clinching composite seal structure as claimed in claim 3, wherein said compensating layer is a metal layer plated on the outer surface of the metal seal base.
5. A self-clinching composite seal structure as set forth in claim 3 wherein said secondary seal layer is a non-metallic layer applied to the outer surface of the metal seal base.
6. A self-tightening composite seal structure according to any one of claims 1 to 5, wherein the ratio of the distance between the upper seal lip and the lower seal lip to the axial thickness of the metal seal ring is 1.15 to 1.4.
7. A self-tightening composite seal structure according to any one of claims 1 to 5, characterized in that the opening angle formed by the upper seal ring and the lower seal ring is 10 ° to 20 °.
8. A self-tightening composite seal structure according to any one of claims 1 to 5, wherein the upper seal lip and the lower seal lip are annular rings protruding in the axial direction, and the circumferential cross section of the annular rings is a sector.
9. The self-tightening composite seal structure according to claim 8, wherein the radius of the sector is 0.5 to 1.5 mm.
10. A self-clinching composite seal structure as claimed in claim 3, wherein said compensating layer is 15 to 40 μm thick.
11. A self-tightening composite sealing structure according to claim 3, characterized in that the secondary sealing layer (8) is made of a flexible graphite material.
12. A self-clinching composite sealing structure as claimed in claim 2, characterized in that said secondary sealing layer (8) is 0.5 to 2mm thick.
13. The self-tightening composite seal structure according to claim 1, wherein the metal seal base has a castellated structure on upper and lower sides of the axis.
14. The self-tightening composite seal structure according to claim 13, wherein the tooth structure is a saw-tooth shape having a tooth height of 0.5mm to 2mm, and the number of teeth is at least 5.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201921359523.XU CN211525774U (en) | 2019-08-20 | 2019-08-20 | Self-tightening type composite sealing structure |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201921359523.XU CN211525774U (en) | 2019-08-20 | 2019-08-20 | Self-tightening type composite sealing structure |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN211525774U true CN211525774U (en) | 2020-09-18 |
Family
ID=72439527
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201921359523.XU Active CN211525774U (en) | 2019-08-20 | 2019-08-20 | Self-tightening type composite sealing structure |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN211525774U (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110594504A (en) * | 2019-08-20 | 2019-12-20 | 北京航天动力研究所 | Self-tightening type composite sealing structure |
-
2019
- 2019-08-20 CN CN201921359523.XU patent/CN211525774U/en active Active
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110594504A (en) * | 2019-08-20 | 2019-12-20 | 北京航天动力研究所 | Self-tightening type composite sealing structure |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN110594504A (en) | Self-tightening type composite sealing structure | |
| CN211259942U (en) | Multistage self-tightening metal sealing structure | |
| CN202851945U (en) | Self-tightening type metal C-shaped sealing ring | |
| CN102168757A (en) | C-shaped cladding sealing ring of built-in spring and manufacturing method thereof | |
| CN211525774U (en) | Self-tightening type composite sealing structure | |
| CN103016867A (en) | Combined gasket | |
| CN202176712U (en) | C-shaped cladding sealing ring with built-in spring | |
| CN110578844A (en) | Multistage self-tightening metal sealing structure | |
| CN202274096U (en) | Embedded type graphite metal gasket | |
| CN112502858A (en) | Gunpowder starter suitable for long-term storage | |
| CN202048234U (en) | High-temperature metal seal ball valve | |
| CN113431901B (en) | Metal ripple self-sealing composite gasket | |
| CN202302432U (en) | Axial double-channel sealing structure for thin-wall flange flat groove for use under complex working condition | |
| CN105042234A (en) | MMC type gasket and design method for flange connection | |
| CN101435506B (en) | Prestress sealing gasket | |
| CN110878836A (en) | Sealing gasket | |
| CN109595411A (en) | A kind of interference-fit type flange | |
| CN216923191U (en) | Rho-shaped sealing ring with built-in spiral spring and mounting structure thereof | |
| CN205896251U (en) | High temperature ball valve that floats sealed firmly | |
| CN111795249B (en) | Compensator and application thereof | |
| CN203052039U (en) | Combined gasket | |
| CN202301937U (en) | Thin-walled flange flat groove radial dual sealing structure for complex working condition | |
| CN105883009B (en) | A kind of high fatigue life metal bellows welding structure | |
| CN220396478U (en) | Deformation-resistant bellows type mechanical seal | |
| CN221683589U (en) | Self-tightening sealing gasket |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| GR01 | Patent grant | ||
| GR01 | Patent grant |