CN217927137U - Anti-back pressure end face sealing structure - Google Patents
Anti-back pressure end face sealing structure Download PDFInfo
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- CN217927137U CN217927137U CN202221939649.6U CN202221939649U CN217927137U CN 217927137 U CN217927137 U CN 217927137U CN 202221939649 U CN202221939649 U CN 202221939649U CN 217927137 U CN217927137 U CN 217927137U
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Abstract
The utility model discloses a prevent back pressure terminal surface seal structure, include: a primary seal disposed between the shaft sleeve and the end cap, the primary seal having: a stationary ring; a moving ring; the bellows assembly is used for pushing the movable ring and the static ring to realize sealing and can normally work when being subjected to forward pressure or reverse pressure; the corrugated pipe assembly is provided with a first corrugated pipe, a second corrugated pipe and a pressure-bearing sleeve which is positioned between the first corrugated pipe and the second corrugated pipe and can bear the pressure difference between the inside and the outside. The corrugated pipe assembly can work normally when being subjected to forward pressure or reverse pressure, and a pressure-bearing sleeve capable of bearing internal and external pressure difference can apply partial pressure to the bearing sleeve when the forward pressure is overlarge or the reverse pressure is overlarge; the first corrugated pipe and the second corrugated pipe move in a proper pressure difference range, the effectiveness of the corrugated pipe assembly is guaranteed, the movable ring is pushed, and the sealing performance of the sealing structure is guaranteed.
Description
Technical Field
The utility model belongs to the technical field of end face seal, concretely relates to prevent back pressure end face seal structure.
Background
With the development of industries such as petroleum and petrochemical industry towards the directions of no pollution, long period, low energy consumption, high benefit and the like, the mechanical seal of a centrifugal pump is required to realize zero leakage, no pollution, long service life and low operation and maintenance cost, particularly, most of pumped fluids in the petroleum and petrochemical industry have the characteristics of flammability, explosiveness, high toxicity, serious pollution and the like, the common contact type mechanical seal cannot meet the requirements, the dry gas seal for the pump adopts the idea of sealing gas with gas or sealing liquid with gas to realize zero escape and zero leakage of process media, the application range of the dry gas seal is wider and wider along with the increasing maturity of the dry gas seal technology, but the common dry gas seal has higher requirement on the purity of the conveyed media to ensure that a stable gas film is formed, and the torus is opened to realize non-contact operation.
However, media of many centrifugal pumps in the actual petroleum and petrochemical industries cannot achieve high purity, often contain solid suspended particles, are toxic, flammable and explosive, and are unstable in pressure of pumping media. Atmospheric side blocking air pressure is higher than medium pressure under the normal condition, but because reasons such as medium pressure unstability, the pressure that can appear the medium is higher than atmospheric side blocking air pressure, and the sealed atress direction of shaft end changes this moment, can lead to shaft end sealing failure.
Most of the existing dry gas sealing devices for pumps can not adapt to the working condition of dangerous media containing suspended solids, the back pressure condition is rarely considered, the operation service life of the existing field sealing devices under the harsh working condition is short, the working efficiency is seriously influenced, and the user cost is increased.
The above information disclosed in this background section is only for enhancement of understanding of the background of the application and therefore it may comprise prior art that does not constitute known to a person of ordinary skill in the art.
Disclosure of Invention
The utility model discloses to foretell problem among the prior art, provide a prevent back pressure terminal surface seal structure, through setting up bellows subassembly, all normally work when receiving forward pressure or backpressure, the bellows seal that has avoided the pressure differential to lead to is inefficacy, is favorable to guaranteeing the leakproofness.
In order to realize the purpose of the utility model, the utility model adopts the following technical scheme to realize:
an anti-back pressure end face seal structure comprising: a primary seal disposed between the shaft sleeve and the end cap, the primary seal having:
a stationary ring provided on the end cap;
the movable ring is arranged on the shaft sleeve;
the bellows assembly is used for pushing the movable ring and the static ring to realize sealing and can normally work when being subjected to forward pressure or reverse pressure;
the corrugated pipe assembly is provided with a first corrugated pipe, a second corrugated pipe and a pressure-bearing sleeve which is positioned between the first corrugated pipe and the second corrugated pipe and can bear the pressure difference between the inside and the outside.
In some embodiments of the present application, the first bellows and the second bellows are arranged in series in an axial direction, and the first bellows is arranged on a side of the pressure-bearing sleeve away from the movable ring.
In some embodiments of the present application, the equilibrium diameter of the first bellows is less than the equilibrium diameter of the second bellows.
In some embodiments of the present application, a driving table is disposed on the shaft sleeve and extends radially outward, and the bellows assembly is disposed on the driving table; when the pressure of sealing fluid on the inner side of the bellows component is larger than the pressure of medium on the outer side, the pressure bearing sleeve can abut against the transmission platform to bear the difference between the inner pressure and the outer pressure.
In some embodiments of the present application, the transmission stage has a transmission stage body, an extension sleeve extending along an outer diameter side of the transmission stage body toward the pressure-bearing sleeve, the extension sleeve is located outside the first corrugated pipe, and a bearing stage notch matched with an end portion of the extension sleeve is arranged on the outer diameter side of the pressure-bearing sleeve.
In some embodiments of the present application, further comprising a push ring disposed between the bellows assembly and the rotating ring; when the medium pressure outside the bellows component is larger than the sealing fluid pressure inside the bellows component, the pressure bearing sleeve can bear against the push ring to bear the internal and external pressure difference.
In some embodiments of the present application, the pressure-bearing sleeve has a pressure-bearing body extending radially, and a pressure-bearing sleeve extending axially along an inner diameter side of the pressure-bearing body toward a direction close to the push ring, where an end surface of the pressure-bearing sleeve close to one end of the push ring is a pressure-bearing surface.
In some embodiments of the present application, the pressure containing sleeve is located inside the second bellows.
In some embodiments of the present application, the second bellows is sealingly welded to the push ring.
In some embodiments of the present application, a first connection ring is further disposed between the pressure-bearing sleeve and the second corrugated pipe, and the first connection ring is fixed to the pressure-bearing sleeve in a sealing manner.
In some embodiments of the present application, the bellows assembly further comprises a second coupling ring disposed between the first bellows and the hub, wherein one end of the first bellows is sealingly coupled to the second coupling ring and the other end of the first bellows is sealingly coupled to the pressure-bearing hub.
In some embodiments of the present application, the seal structure further comprises a safety seal disposed between the end cap and the shaft sleeve, the safety seal is close to the atmosphere side, the main seal is close to the medium side, and a fluid seal cavity is defined between the back-pressure-proof end face seal structure and the shaft sleeve.
In some embodiments of the present application, a sealing gas is introduced into the fluid-tight chamber.
Compared with the prior art, the utility model discloses an advantage is with positive effect: the corrugated pipe assembly can work normally when being subjected to forward pressure or reverse pressure, and partial pressure can be applied to the pressure-bearing sleeve when the forward pressure or the reverse pressure is overlarge through the pressure-bearing sleeve which can bear the pressure difference between the inside and the outside; the first corrugated pipe and the second corrugated pipe move in a proper pressure difference range, the effectiveness of the corrugated pipe assembly is guaranteed, the movable ring is pushed, and the sealing performance of the sealing structure is guaranteed.
Other features and advantages of the present invention will become more apparent from the following detailed description of the invention when read in conjunction with the accompanying drawings.
Drawings
In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings needed to be used in the embodiments will be briefly described below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings without creative efforts.
Fig. 1 is a schematic structural diagram of an embodiment of an anti-back pressure end face seal structure proposed by the present invention;
fig. 2 is a partially enlarged schematic view of fig. 1.
Wherein, the shaft sleeve 100; a drive stage 110; a drive table body 111; an extension sleeve 112;
an end cap 200;
a primary seal 300; a rotating ring 310; a stationary ring 320; a bellows assembly 330; a first bellows 331; a second bellows 332; a pressure-bearing sleeve 333; a pressure-bearing body 3330; a cushion cap notch 3331; a pressure-bearing sleeve 3332; a first connecting ring 334; a second connection ring 335; a push ring 340;
a security seal 400.
Detailed Description
In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the drawings in the embodiments of the present invention are combined below to clearly and completely describe the technical solutions in the embodiments of the present invention.
In the description of the present invention, it should be noted that the terms "upper", "lower", "left", "right", and the like indicate orientations or positional relationships based on the positional relationships shown in the drawings, and the directions close to the rotation axis are "inner" and vice versa. The terminology is for the purpose of describing the invention only and is for the purpose of simplifying the description and is not intended to indicate or imply that the apparatus or components so referred to must have a particular orientation, be constructed and operated in a particular orientation and is in no way to be considered limiting of the invention. Moreover, the terms "first," "second," and "third" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance; the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, "a plurality" means two or more unless specifically limited otherwise.
In the present invention, unless otherwise explicitly specified or limited, the terms "mounted," "connected," "secured," and the like are to be construed broadly, e.g., as being fixedly connected, detachably connected, or integrated; can be mechanically or electrically connected; either directly or indirectly through intervening media, either internally or in any other relationship. The specific meaning of the above terms in the present invention can be understood according to specific situations by those skilled in the art.
In the present disclosure, unless expressly stated or limited otherwise, the first feature "on" or "under" the second feature may comprise direct contact between the first and second features, or may comprise contact between the first and second features not directly. Also, the first feature being "on," "above" and "over" the second feature includes the first feature being directly on and obliquely above the second feature, or merely indicating that the first feature is at a higher level than the second feature. A first feature being "under," "below," and "beneath" a second feature includes the first feature being directly under and obliquely below the second feature, or simply meaning that the first feature is at a lesser elevation than the second feature.
The following disclosure provides many different embodiments or examples for implementing different features of the invention. To simplify the disclosure of the present invention, specific example components and arrangements are described below. Of course, they are merely examples and are not intended to limit the present invention. Furthermore, the present disclosure may repeat reference numerals and/or reference letters in the various examples for purposes of simplicity and clarity and do not in itself dictate a relationship between the various embodiments and/or arrangements discussed. In addition, the present disclosure provides examples of various specific processes and materials, but one of ordinary skill in the art may recognize applications of other processes and/or use of other materials.
Referring to fig. 1 and fig. 2, the utility model provides an embodiment of the anti-back pressure end face seal structure that prevents, an anti-back pressure end face seal structure includes: a primary seal 300 and a safety seal 400 disposed between the shaft sleeve 100 and the end cap 200, the primary seal 300 being adjacent to the media side and the safety seal 400 being adjacent to the atmosphere side; in this embodiment, the main seal 300 is a dry gas seal, an air film is formed between the moving ring 310 and the stationary ring 320 of the main seal 300 to realize sealing, and the medium pressure outside the main seal 300 is normally lower than the sealing gas pressure inside the main seal 300; when the media pressure is unstable, it may occur that the media pressure outside the primary seal 300 is greater than the seal gas pressure inside the primary seal 300.
In other embodiments, the primary seal 300 may also be considered a liquid film seal, where the pressure of the medium outside the primary seal 300 is normally less than the pressure of the sealing liquid inside the primary seal 300.
The primary seal 300 comprises a moving ring 310, a stationary ring 320 and a bellows assembly 330, wherein the moving ring 310 is arranged on the shaft sleeve 100, and the stationary ring 320 is arranged on the end cover 200; the bellows assembly 330 is used to push the seal between the moving ring 310 and the stationary ring 320, and the bellows assembly 330 can work normally when being subjected to a forward pressure or a reverse pressure. Under normal conditions of operation of the anti-back pressure end face sealing structure, the pressure applied to the bellows assembly 330 is a forward pressure, that is, the pressure of the sealing gas inside the bellows assembly 330 is greater than the pressure of the medium outside the bellows assembly 330, that is, the pressure difference applied to the bellows assembly 330 is an urging force given by the sealing gas to move to the medium side. When the reverse pressure is greater than the sealing gas pressure, the pressure difference applied to the bellows assembly 330 is the pushing force given by the medium to move to the atmosphere side.
In order to ensure that the bellows assembly 330 can work normally when the bellows assembly 330 is subjected to a forward pressure or a reverse pressure, the bellows assembly 330 is provided with a first bellows 331, a second bellows 332, and a pressure-bearing sleeve 333 positioned between the first bellows 331 and the second bellows 332, and the pressure-bearing sleeve 333 can bear the difference between the internal pressure and the external pressure of the main seal 300. When the pressure difference between the inside and the outside of the primary seal 300 is small, the pressure difference directly acts on the bellows assembly 330 to push the movement of the bellows assembly 330; after the axial movement of the bellows assembly 330 reaches a predetermined value, if the pressure difference between the inside and the outside of the main seal 300 continues to increase, the pressure-bearing sleeve 333 receives the pressure difference that continues to increase, so as to prevent a larger pressure difference from acting on the bellows assembly 330, which may result in failure of the bellows assembly 330.
In the embodiment, the bellows assembly 330 is arranged to work normally when subjected to a forward pressure or a reverse pressure, and the pressure-bearing sleeve 333 capable of bearing an internal pressure difference and an external pressure difference is arranged to apply a part of pressure to the pressure-bearing sleeve 333 when the forward pressure is too high or the reverse pressure is too high; the first bellows 331 and the second bellows 332 are enabled to move within a proper pressure difference range, effectiveness of the bellows assembly 330 is guaranteed, pushing of the moving ring is achieved, and sealing performance of the sealing structure is guaranteed.
In some embodiments of the present application, the first bellows 331 and the second bellows 332 are arranged in series in the axial direction, and the first bellows 331 is on a side of the pressure-containing sleeve 333 away from the rotating ring 310. The equilibrium diameter of the first bellows 331 is smaller than the equilibrium diameter of the second bellows 332, and the equilibrium diameter of the first bellows 331 is an average of the inner diameter and the outer diameter of the first bellows 331.
In some embodiments of the present application, a driving table 110 is disposed on the sleeve 100 and extends radially outward, and the bellows assembly 330 is disposed on the driving table 110; when the sealing fluid pressure inside the bellows assembly 330 is greater than the media pressure outside, the pressure sleeve 333 may bear against the drive table 110 to accommodate the difference between the inside and outside pressures.
In some embodiments of the present application, the transmission table 110 has a transmission table body 111, an extension sleeve 112 extending along an outer diameter side of the transmission table body 111 toward the pressure receiving sleeve 333, the extension sleeve 112 is located outside the first corrugated tube 331, and a table notch 3331 for matching with an end of the extension sleeve 112 is provided on the outer diameter side of the pressure receiving sleeve 333. The extension sleeve 112 and the pressure-bearing sleeve 333 are arranged at intervals, when the sealing fluid pressure inside the bellows assembly 330 is greater than the medium pressure outside, the bellows assembly 330 is pushed to move towards the direction of the movable ring 310, so that the extension sleeve 112 and the pressure-bearing sleeve 333 are abutted; at this time, the first bellows 331 is in a failure state in the axial direction, cannot move in the axial direction, and cannot provide thrust to the moving ring 310; most of the increased pressure difference can be borne by the pressure bearing sleeve 333; and the second bellows 332 is axially movable and in an operating state, and can provide a pushing force for the movable ring 310.
In some embodiments of the present application, a push ring 340 disposed between the bellows assembly 330 and the rotating ring 310; when the pressure of the medium outside the bellows assembly 330 is greater than the pressure of the sealing fluid inside the bellows assembly, i.e., in a back pressure state, the pressure-containing sleeve 333 can bear against the push ring 340 to contain the difference between the internal pressure and the external pressure.
In some embodiments of the present application, the bearing sleeve 333 has a bearing body 3330 extending radially, a bearing sleeve 3332 extending axially along an inner diameter side of the bearing body 3330 to a direction close to the push ring 340, and a bearing surface is formed on an end surface of the bearing sleeve 3332 close to one end of the push ring 340. When the pressure of the medium outside the bellows assembly 330 is greater than the pressure of the sealing fluid inside the bellows assembly 330, the pressure difference between the inside and the outside of the bellows assembly 330 pushes the bellows assembly 330 to move toward the movable ring 310, so that the distance between the pressure-bearing sleeve 3332 and the push ring 340 decreases; after the pressure-bearing sleeve 3332 abuts against the push ring 340, the driving force between the internal and external pressure differences is directly transmitted to the push ring 340 through the pressure-bearing sleeve 3332. At this time, the second bellows 332 cannot move in the axial direction and is in a failure state; the first bellows 310 is in a normal operating state.
In some embodiments of the present application, the pressure-bearing sleeve 3332 is located inside the second bellows 332, and the second bellows 332 is fixed to the push ring 340 by sealing welding. A first connecting ring 334 is further arranged between the pressure-bearing sleeve 333 and the second corrugated pipe 332, and the first connecting ring 334 is fixed with the pressure-bearing sleeve 333 in a sealing manner.
In some embodiments of the present application, the bellows assembly 330 further has a second connection ring 335 disposed between the first bellows 331 and the hub 100, with one end of the first bellows 331 being sealingly connected to the second connection ring 335 and the other end being sealingly connected to the pressure jacket 333.
The above embodiments are only used to illustrate the technical solution of the present invention, and not to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, it will be apparent to those skilled in the art that modifications may be made to the embodiments described in the foregoing embodiments, or that equivalents may be substituted for elements thereof; such modifications and substitutions do not depart from the spirit and scope of the present invention, which is claimed in the appended claims.
Claims (10)
1. A back pressure prevention end face sealing structure is characterized by comprising: a primary seal disposed between the shaft sleeve and the end cap, the primary seal having:
a stationary ring provided on the end cap;
the movable ring is arranged on the shaft sleeve;
the bellows assembly is used for pushing the movable ring and the static ring to realize sealing and can work normally when being subjected to forward pressure or reverse pressure;
the corrugated pipe assembly is provided with a first corrugated pipe, a second corrugated pipe and a pressure-bearing sleeve which is positioned between the first corrugated pipe and the second corrugated pipe and can bear the pressure difference between the inside and the outside.
2. The anti-back pressure end face seal structure according to claim 1, characterized in that the first bellows and the second bellows are arranged in series in the axial direction, and the first bellows is arranged on the side of the pressure-bearing sleeve away from the rotating ring.
3. An anti-back pressure end face seal structure according to claim 2, characterized in that the equilibrium diameter of the first bellows is smaller than the equilibrium diameter of the second bellows.
4. The back pressure prevention end face seal structure according to any one of claims 1 to 3, wherein a drive table is provided on the boss so as to extend radially outward, the bellows assembly being provided on the drive table; when the pressure of sealing fluid on the inner side of the bellows component is larger than the pressure of medium on the outer side, the pressure bearing sleeve can abut against the transmission platform to bear the difference between the inner pressure and the outer pressure.
5. The back pressure prevention end face sealing structure according to claim 4, wherein the drive table has a drive table body, and an extension sleeve extending in the direction of the pressure-bearing sleeve along the outer diameter side of the drive table body, the extension sleeve is located outside the first corrugated pipe, and a bearing table notch for matching with the end of the extension sleeve is provided on the outer diameter side of the pressure-bearing sleeve.
6. A back pressure resistant end face seal structure according to any one of claims 1 to 3, further comprising a push ring provided between the bellows assembly and the moving ring; when the medium pressure outside the bellows component is larger than the sealing fluid pressure inside the bellows component, the pressure bearing sleeve can bear against the push ring to bear the internal and external pressure difference.
7. The anti-back pressure end face sealing structure according to claim 6, wherein the pressure bearing sleeve is provided with a pressure bearing body extending radially, a pressure bearing sleeve extending axially along the inner diameter side of the pressure bearing body in the direction close to the push ring, and the end face of the pressure bearing sleeve at one end close to the push ring is a pressure bearing face; the pressure-bearing sleeve is positioned on the inner side of the second corrugated pipe.
8. An anti-back pressure end face sealing structure according to any one of claims 1 to 3, characterized in that a first connecting ring is further arranged between the pressure-bearing sleeve and the second corrugated pipe, and the first connecting ring is fixed with the pressure-bearing sleeve in a sealing manner.
9. A back pressure resistant end face seal construction according to any one of claims 1 to 3, wherein the bellows assembly further has a second connecting ring disposed between the first bellows and the boss, the first bellows having one end sealingly connected to the second connecting ring and the other end sealingly connected to the pressure-receiving sleeve.
10. A back pressure prevention end face seal structure according to any one of claims 1 to 3, further comprising a safety seal disposed between the end cap and the shaft sleeve, the safety seal being adjacent to the atmosphere side, the primary seal being adjacent to the media side, and a fluid tight chamber being enclosed between the back pressure prevention end face seal structure and the shaft sleeve.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202221939649.6U CN217927137U (en) | 2022-07-26 | 2022-07-26 | Anti-back pressure end face sealing structure |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202221939649.6U CN217927137U (en) | 2022-07-26 | 2022-07-26 | Anti-back pressure end face sealing structure |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN217927137U true CN217927137U (en) | 2022-11-29 |
Family
ID=84149877
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202221939649.6U Active CN217927137U (en) | 2022-07-26 | 2022-07-26 | Anti-back pressure end face sealing structure |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN217927137U (en) |
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2022
- 2022-07-26 CN CN202221939649.6U patent/CN217927137U/en active Active
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