High-pressure-resistant dry gas sealing device

Abstract

The utility model relates to a high-pressure-resistant dry gas sealing device which comprises a shaft sleeve, a cavity, a movable ring assembly and a static ring assembly, the shaft sleeve is fixed on a rotating shaft, the movable ring assembly is fixed outside the shaft sleeve and rotates synchronously with the shaft sleeve, the static ring assembly is fixed in the cavity, and the cavity is fixed on the rotating shaft. The moving ring assembly and the static ring assembly abut against each other to form a first sealing face, the static ring assembly comprises a spring seat, a static ring, a spring and a ring pushing unit, the spring seat is fixed to the cavity, the static ring and the spring seat are fixed through an anti-rotating pin, the front end of the static ring abuts against the moving ring assembly to form the first sealing face, and the spring is fixed to the spring seat through an anti-rotating pin. The tail end of the static ring abuts against the push ring unit to form a second sealing face, and the spring is arranged between the spring seat and the push ring unit. The sealing device has a good sealing effect on sealing of high-pressure media, and is long in service life.

Description

Technical Field

[0001] The utility model relates to the technical field of mechanical seals, in particular to a high-pressure resistant dry gas sealing device. Background Art

[0002] Dry gas seal is the abbreviation of dry-running, gas-lubricated, non-contact mechanical seal. It has the characteristics and advantages of gas-to-gas, non-contact, gas film lubrication, low power consumption, long life, and high reliability. The stability of dry gas seal is closely related to the pressure of the sealed medium. There are many differences in design between high-pressure dry gas seal and conventional dry gas seal. When the pressure of the sealing medium is low, there is a lot of room for the structural design, dimensional accuracy, material selection, assembly requirements, etc. of the seal. With the increase of the pressure of the sealing medium, there are problems such as increased deformation of the secondary seal and the end face, stuck secondary seal O-ring, rapid decompression causing O-ring bursting, and increased leakage of the end face seal. Therefore, for high-pressure dry gas seals, only redesign from the aspects of structure, material, and process can meet the requirements of actual use. Utility Model Content

[0003] The purpose of the utility model is to provide a high-pressure dry gas sealing device in order to overcome the defects of the prior art.

[0004] In order to achieve the purpose of the utility model, the present application provides the following technical solutions.

[0005] In a first aspect, the present application provides a high-pressure dry gas resistant sealing device, the sealing device comprising a sleeve, a cavity, a dynamic ring assembly and a stationary ring assembly, the sleeve being fixed on a rotating shaft, the dynamic ring assembly being fixed on the outside of the sleeve and rotating synchronously with the sleeve, the stationary ring assembly being fixed in the cavity, the dynamic ring assembly and the stationary ring assembly abutting against each other to form a first sealing surface, the stationary ring assembly comprising a spring seat, a stationary ring, a spring and a push ring unit, the spring seat being fixed on the cavity, the stationary ring and the spring seat being fixed by an anti-rotation pin, the front end of the stationary ring abutting against the dynamic ring assembly to form a first sealing surface, the rear end of the stationary ring abutting against the push ring unit to form a second sealing surface, and the spring being arranged between the spring seat and the push ring unit.

[0006] In one embodiment of the first aspect, the push ring unit includes a push ring, an elastic energy storage ring and a push ring pressure plate, the push ring includes an outer ring, a connecting part and an inner ring that are integrally formed and connected in sequence, the outer ring and the inner ring are perpendicular to the axis of the rotating shaft, the connecting part is parallel to the axis of the rotating shaft, the front end side surface of the outer ring abuts against the tail end of the static ring, the front end of the push ring pressure plate abuts against the tail end of the static ring and forms a second sealing surface, and the front end of the push ring pressure plate and the inner ring clamp the elastic energy storage ring in the middle.

[0007] In one implementation of the first aspect, the push ring pressure plate is made of cemented carbide, and the front end side surface of the push ring pressure plate is ground and completely fits with the rear end of the stationary ring.

[0008] In one embodiment of the first aspect, a balancing sleeve is fixed on the spring seat, a spring loading ring is provided between the balancing sleeve and the spring seat, the balancing sleeve is arranged coaxially with the rotating shaft, the static ring, push ring, elastic energy storage ring and push ring pressure plate are all sleeved on the outer wall of the balancing sleeve, and the static ring, push ring, elastic energy storage ring and push ring pressure plate are in contact with the outer wall of the balancing sleeve.

[0009] In an implementation of the first aspect, the elastic energy storage ring is made of polytetrafluororubber, and the elastic energy storage ring is interference-fitted on the outer wall of the balancing sleeve.

[0010] In an implementation manner of the first aspect, a retaining ring is provided on the spring seat, and the retaining ring is used to limit the axial movement of the stationary ring.

[0011] In one embodiment of the first aspect, the dynamic ring assembly includes a dynamic ring seat and a dynamic ring, the dynamic ring seat is fixed to the shaft sleeve, and a spring loading ring is provided between the dynamic ring seat and the shaft sleeve, the dynamic ring and the dynamic ring seat are fixed by a transmission pin, and the tail end side surface of the dynamic ring abuts against the front end side surface of the stationary ring to form a first sealing surface.

[0012] In one implementation of the first aspect, a micrometer-scale shallow groove is provided on the side surface of the tail end of the moving ring.

[0013] In one embodiment of the first aspect, the moving ring seat includes an outer seat, a connecting seat and an inner seat that are integrally formed and connected in sequence, the outer seat and the inner seat are parallel to the axial direction of the rotating shaft, the connecting seat is perpendicular to the axis of the rotating shaft, the moving ring is installed between the outer seat, the connecting seat and the inner seat, and a centering spring is provided on the inner seat, the centering spring abuts against the inner wall of the moving ring, and a spring loading ring is provided between the moving ring and the moving ring seat.

[0014] In an implementation of the first aspect, a compression sleeve is fixed on the inner seat, a spring loading ring is provided between the compression sleeve and the inner seat, and a front end of the compression sleeve abuts against an end surface of the rear end of the moving ring.

[0015] Compared with the prior art, the beneficial effects of the utility model are:

[0016] (1) The dynamic ring and the static ring are matched in a hard-to-hard manner to improve the pressure-bearing capacity of the friction pair. The deformation problem of the sealing end face under high pressure is improved by optimizing the dynamic and static ring structures.

[0017] (2) The push ring assembly structure includes three parts, namely, a push ring pressure piece, an elastic energy storage ring, and a push ring. The push ring pressure piece is made of cemented carbide material. The boss of the push ring pressure piece fits the back of the static ring. The process requirements for the flatness, roughness, and verticality of the push ring pressure piece boss are very high. In actual operation, the push ring pressure piece boss plays a sealing role with the static ring. The dimensional design requirements of the elastic energy storage ring are also very high. In the actual working process, the elastic energy storage ring can creep axially on the balance sleeve under the action of the spring, playing the role of a secondary seal.

[0018] (3) The balancing sleeve is made of cemented carbide and has high surface processing accuracy requirements to reduce deformation under high-pressure conditions. Its surface finish requirements are very high, which is conducive to the axial sliding of the secondary sealing elastic energy storage ring to prevent sticking and play a sealing role.

[0019] (4) The static seal of the entire dry gas seal adopts a spring-loaded ring to prevent the O-ring from bursting due to rapid decompression.

[0020] (5) A centering spring structure is used at the bottom of the moving ring to center the moving ring and prevent it from moving in the radial direction.

[0021] (6) The moving ring is installed in a floating manner on the moving ring seat, which is conducive to the deformation of the moving ring under high pressure. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 This is a partial cross-sectional structural schematic diagram of the sealing device of the present application.

[0023] In the accompanying drawings, 1 is a dynamic ring, 2 is a static ring, 3 is a push ring pressure plate, 4 is an elastic energy storage ring, 5 is a push ring, 6 is a spring, 7 is an anti-rotation pin, 8 is a centering spring, 9 is a spring loading ring, 10 is a dynamic ring seat, 11 is a transmission pin, 12 is a screw, 13 is a clamping sleeve, 14 is a balancing sleeve, 15 is a spring loading ring, 16 is a spring seat, 17 is a spring loading ring, 18 is a retaining ring, 19 is a spring loading ring, 20 is an outer ring, 21 is a connecting part, 22 is an inner ring, 23 is an outer seat, 24 is a connecting seat, and 25 is an inner seat. DETAILED DESCRIPTION

[0024] Unless otherwise defined, the technical terms or scientific terms used in this specification and claims shall have the ordinary meanings understood by persons with ordinary skills in the technical field to which the utility model belongs. All the values ​​from the lowest value to the highest value listed in this article refer to all the values ​​obtained by incrementing one unit between the lowest value and the highest value when the difference between the lowest value and the highest value is more than two units.

[0025] The following will describe the specific implementation of the utility model. It should be noted that in the specific description of these implementations, in order to provide a concise description, this specification cannot provide a detailed description of all the features of the actual implementation. Without departing from the spirit and scope of the utility model, those skilled in the art may modify and replace the implementation of the utility model, and the resulting implementation is also within the scope of protection of the utility model.

[0026] The purpose of this application is to provide a high-pressure dry gas sealing device, the basic structure of which is a hard-to-hard pairing of a dynamic and static ring, such as silicon carbide to silicon carbide + DLC; the push ring combination structure includes a push ring pressure plate, an elastic energy storage ring, and a push ring. The push ring combination is composed of a spring installed in the spring seat acting on the back of the static ring; the carbide balance sleeve is separated from the spring seat, and the static seal is achieved by the spring loading ring; the centering spring on the dynamic ring seat plays the role of centering the dynamic ring, and the dynamic ring rotates with the dynamic ring seat by the transmission pin on the dynamic ring seat, the clamping sleeve is connected to the dynamic ring seat with a screw, and the dynamic ring is floatingly installed on the dynamic ring seat, and the spring loading ring plays the role of static sealing between the two. This structure is the most basic structural type of a high-pressure dry gas sealing device proposed in this patent. Through the combination of the basic structure, a variety of sealing arrangements can be formed, such as tandem dry gas seals, double-end dry gas seals, etc.

[0027] In a specific embodiment, the present application provides a high-pressure dry gas sealing device, the sealing device includes a sleeve, a cavity, a dynamic ring assembly and a static ring assembly, the sleeve is fixed on the rotating shaft, the dynamic ring assembly is fixed outside the sleeve and rotates synchronously with the sleeve, the static ring assembly is fixed in the cavity, the dynamic ring assembly and the static ring assembly abut against each other to form a first sealing surface, the static ring assembly includes a spring seat, a static ring, a spring and a push ring unit, the spring seat is fixed on the cavity, the static ring and the spring seat are fixed by an anti-rotation pin, the front end of the static ring abuts against the dynamic ring assembly and forms a first sealing surface, the tail end of the static ring abuts against the push ring unit to form a second sealing surface, and the spring is arranged between the spring seat and the push ring unit. The function of the spring is to provide elastic force so that the static ring and the dynamic ring are always in close contact, that is, to ensure the sealing of the first sealing surface. In the present application, there are two types of seals between the stationary ring and the spring seat. The first type is between the stationary ring and the push ring unit. The elastic force of the spring also makes the stationary ring and the push plate unit always close to each other, that is, the sealing of the second sealing surface is guaranteed. In addition, both sides of the first sealing surface and the second sealing surface are made of cemented carbide, which has little deformation in a high-pressure medium environment. As long as the two sides of the first sealing surface and the second sealing surface are sufficiently flat and smooth, they can play a good sealing role and will not fail due to the high-pressure medium.

[0028] In a specific embodiment, the push ring unit includes a push ring, an elastic energy storage ring and a push ring pressure plate, the push ring includes an outer ring, a connecting part and an inner ring that are integrally formed and connected in sequence, the outer ring and the inner ring are perpendicular to the axis of the rotating shaft, the connecting part is parallel to the axis of the rotating shaft, the front end side surface of the outer ring abuts against the tail end of the static ring, the front end of the push ring pressure plate abuts against the tail end of the static ring and forms a second sealing surface, and the front end of the push ring pressure plate and the inner ring clamp the elastic energy storage ring in the middle.

[0029] In a specific embodiment, the push ring pressure plate is made of cemented carbide, and the front side of the push ring pressure plate is ground and completely fits with the rear end of the stationary ring. The push ring pressure plate fits with the back of the stationary ring, and the process requirements for the flatness, roughness, verticality, etc. of the push ring pressure plate are very high. In actual operation, the push ring pressure plate plays a sealing role with the stationary ring.

[0030] In a specific embodiment, a balancing sleeve is fixed on the spring seat, a spring loading ring is arranged between the balancing sleeve and the spring seat, the balancing sleeve is arranged coaxially with the rotating shaft, the static ring, the push ring, the elastic energy storage ring and the push ring pressure plate are all sleeved on the outer wall of the balancing sleeve, and the static ring, the push ring, the elastic energy storage ring and the push ring pressure plate are in contact with the outer wall of the balancing sleeve. The balancing sleeve is made of cemented carbide, and its surface processing accuracy is very high to reduce deformation under high pressure conditions. Its surface finish is very high, which is conducive to the axial sliding of the secondary sealing elastic energy storage ring to prevent jamming and play a sealing role at the same time.

[0031] In a specific embodiment, the elastic energy storage ring is made of polytetrafluoroethylene rubber, and the elastic energy storage ring is an interference sleeve on the outer wall of the balancing sleeve. The second sealing form between the spring seat and the static ring is between the spring energy storage ring and the balancing sleeve. The polytetrafluoroethylene rubber has a small deformation under high pressure, and the dimensional design requirements of the elastic energy storage ring are also very high. In the actual working process, the elastic energy storage ring can creep axially on the balancing sleeve under the action of the spring, playing the role of secondary sealing.

[0032] In a specific embodiment, a snap ring is provided on the spring seat, and the snap ring is used to limit the axial movement of the stationary ring. The snap ring is mainly used when the stationary ring is installed. Due to the elastic force of the spring, the stationary ring will be pushed toward the front end, occupying the installation space of the dynamic ring, making it impossible to install the dynamic ring. The existing technology is to manually push the stationary ring backward to overcome the elastic force of the spring, and then install the dynamic ring. This method is more troublesome in actual operation. Therefore, the present application is provided with a snap ring to limit the forward movement of the stationary ring, thereby facilitating the installation of the dynamic ring.

[0033] In a specific embodiment, the dynamic ring assembly includes a dynamic ring seat and a dynamic ring, the dynamic ring seat is fixed to the shaft sleeve, and a spring loading ring is provided between the dynamic ring seat and the shaft sleeve, the dynamic ring and the dynamic ring seat are fixed by a transmission pin, and the tail end side of the dynamic ring abuts against the front end side of the stationary ring to form a first sealing surface.

[0034] In a specific embodiment, a micron-sized shallow groove is provided on the side of the tail end of the dynamic ring. The depth of the shallow groove can be selected between 6μm and 10μm. When in use, the sealing gas will enter the shallow groove, thereby forming a gas film on the contact surface of the dynamic ring and the static ring to prevent leakage of the fluid medium.

[0035] In a specific embodiment, the dynamic ring seat includes an outer seat, a connecting seat and an inner seat which are integrally formed and connected in sequence, the outer seat and the inner seat are parallel to the axial direction of the rotating shaft, the connecting seat is perpendicular to the axis of the rotating shaft, the dynamic ring is installed between the outer seat, the connecting seat and the inner seat, and a centering spring is provided on the inner seat, the centering spring abuts against the inner wall of the dynamic ring, and a spring loading ring is provided between the dynamic ring and the dynamic ring seat. The centering spring plays a role in radial centering of the dynamic ring.

[0036] In a specific embodiment, a compression sleeve is fixed on the inner seat, a spring loading ring is provided between the compression sleeve and the inner seat, and the front end of the compression sleeve abuts against the end surface of the rear end of the moving ring. The compression sleeve can play the role of axial limiting the moving ring.

[0037] Example

[0038] The following is a detailed description of an embodiment of the present invention. This embodiment is implemented based on the technical solution of the present invention, and a detailed implementation method and a specific operation process are given, but the protection scope of the present invention is not limited to the following embodiment.

[0039] Example 1

[0040] A high pressure dry gas sealing device, part of which is as follows Figure 1 As shown, Figure 1 The mechanical seal cavity, sleeve, and rotating shaft are omitted, and the entire sealing device is annular and sleeved on the rotating shaft. Figure 1 Only half of the cross-sectional view is shown, but the above structures are all prior art and are not described in detail in this application.

[0041] 1. The moving ring 1 is floatingly mounted on the moving ring seat 10 and fixed by a transmission pin 11. The transmission pin 11 plays a role in driving the moving ring 1, so that the moving ring 1 and the moving ring seat 10 rotate synchronously. The moving ring seat 10 includes an outer seat 23, a connecting seat 24 and an inner seat 25. The outer seat 23 and the inner seat 25 are parallel to the axial direction of the rotating shaft, and the connecting seat 24 is perpendicular to the axis of the rotating shaft. The spring loading ring 9 is installed on the connecting seat 24 to play a role of static sealing between the moving ring 1 and the moving ring seat 10. The centering spring 8 is installed on the inner seat 25 to play a role of radial centering of the moving ring 1. The clamping sleeve 13 is connected to the tail end of the inner seat 25 with a screw 12, and the front end of the clamping sleeve 13 abuts against the moving ring 1. The clamping sleeve 13 plays a role of axial limiting the moving ring 1. The spring loading ring 17 is installed on the clamping sleeve 13 to play a role of static sealing between the clamping sleeve 13 and the inner seat 25. The spring loading ring 19 is installed on the moving ring seat 10 to play a role of static sealing between the seal and the rotating shaft (the rotating shaft is not shown in the figure). This part is the rotating part of the dry gas seal.

[0042] 2. The stationary ring 2 is installed on the spring seat 16 and is prevented from rotating by the anti-rotation pin 7 installed on the spring seat 16. The snap ring 18 installed on the spring seat 16 serves to limit the axial position of the stationary ring 2. The spring 6 is installed in the spring hole of the spring seat 16 and acts on the push ring 5. The push ring 5 includes an outer ring 20, a connecting portion 21 and an inner ring 22 which are integrally formed and connected in sequence. The outer ring 20 and the inner ring 22 are perpendicular to the axis of the rotating shaft, and the connecting portion 21 is parallel to the axis of the rotating shaft. The spring 6 abuts against the outer ring 20 of the push ring 5. The front end side surface of the push ring pressure plate 3 is fitted with the rear end side surface of the static ring 2, the rear end of the push ring pressure plate 3 is fitted with the elastic energy storage ring 4, the elastic energy storage ring 4 is fitted with the inner ring 22 of the push ring 5, and under the action of the spring force, the push ring pressure plate 3, the elastic energy storage ring 4 and the push ring 5 can move axially on the balancing sleeve 14, and the balancing sleeve 14 is installed on the spring seat 16. The static seal between the two is completed by the spring loading ring 15. This part is the stationary part of the dry gas seal.

[0043] 3. The friction pair consisting of the dynamic ring 1 and the static ring 2 is the core component of the dry gas seal. The end face of the dynamic ring 1 is engraved with a micron-level shallow groove. Under normal working conditions, the gas enters from the outer diameter of the end face of the dynamic ring. Under the action of the fluid dynamic pressure groove, a very thin air film is formed between the end faces of the dynamic and static rings to prevent leakage of the fluid medium.

[0044] This patent proposes a high-pressure dry gas sealing device, the core component of which is a friction pair consisting of a pair of hard-on-hard dynamic rings 1 and a static ring 2. The back of the static ring 2 is composed of a push ring combination structure consisting of a push ring pressure plate 3, an elastic energy storage ring 4, and a push ring 5. This structural design is an innovation of this patent, in which the push ring pressure plate 3 is completely in contact with the back of the static ring 2, and the elastic energy storage ring 4 is installed between the push ring pressure plate 3 and the push ring 5, playing the role of secondary sealing. The design of the size of the elastic energy storage ring 4 is extremely critical. In addition, the split design of the balance sleeve 14 and the spring seat 16 is another innovation of this patent. The material of the balance sleeve 14 is cemented carbide, which reduces the problem of high-pressure deformation. The roundness and surface finish of the balance sleeve 14 are very high, ensuring that the elastic energy storage ring 4 plays a sealing role while moving smoothly on its surface. Finally, the static seal of the entire dry gas seal adopts a spring loading ring to prevent the O-ring from bursting when the O-ring is quickly decompressed.

[0045] The above description of the embodiments is to facilitate those of ordinary skill in the art to understand and apply the present application. It is obvious that those familiar with the art can easily make various modifications to these embodiments and apply the general principles described herein to other embodiments without having to pay creative labor. Therefore, the present application is not limited to the embodiments herein, and improvements and modifications made by those skilled in the art based on the contents disclosed in the present application without departing from the scope and spirit of the present application are within the scope of the present application.

Claims

1. A high-pressure dry gas sealing device, comprising a sleeve, a cavity, a dynamic ring assembly and a static ring assembly, wherein the sleeve is fixed on a rotating shaft, the dynamic ring assembly is fixed outside the sleeve and rotates synchronously with the sleeve, the static ring assembly is fixed in the cavity, the dynamic ring assembly and the static ring assembly abut against each other to form a first sealing surface, characterized in that: The stationary ring assembly includes a spring seat, a stationary ring, a spring and a push ring unit. The spring seat is fixed on the cavity. The stationary ring and the spring seat are fixed by an anti-rotation pin. The front end of the stationary ring abuts against the dynamic ring assembly to form a first sealing surface. The rear end of the stationary ring abuts against the push ring unit to form a second sealing surface. The spring is arranged between the spring seat and the push ring unit.

2. The high pressure resistant dry gas sealing device according to claim 1, characterized in that: The push ring unit includes a push ring, an elastic energy storage ring and a push ring pressure plate. The push ring includes an outer ring, a connecting part and an inner ring that are integrally formed and connected in sequence. The outer ring and the inner ring are perpendicular to the axis of the rotating shaft, and the connecting part is parallel to the axis of the rotating shaft. The front end side surface of the outer ring abuts against the tail end of the static ring, and the front end of the push ring pressure plate abuts against the tail end of the static ring to form a second sealing surface. The front end of the push ring pressure plate and the inner ring clamp the elastic energy storage ring in the middle.

3. The high pressure resistant dry gas sealing device according to claim 2, characterized in that: The push ring pressure plate is made of hard alloy, and the front end side surface of the push ring pressure plate is ground and completely fits with the rear end of the stationary ring.

4. The high pressure resistant dry gas sealing device according to claim 2, characterized in that: A balancing sleeve is fixed on the spring seat, a spring loading ring is provided between the balancing sleeve and the spring seat, the balancing sleeve is arranged coaxially with the rotating shaft, the static ring, push ring, elastic energy storage ring and push ring pressure plate are all sleeved on the outer wall of the balancing sleeve, and the static ring, push ring, elastic energy storage ring and push ring pressure plate are in contact with the outer wall of the balancing sleeve.

5. The high pressure resistant dry gas sealing device according to claim 4, characterized in that: The elastic energy storage ring is made of tetrafluororubber, and the elastic energy storage ring is interference-fitted on the outer wall of the balancing sleeve.

6. The high pressure resistant dry gas sealing device according to claim 1, characterized in that: A snap ring is provided on the spring seat, and the snap ring is used to limit the axial movement of the stationary ring.

7. The high pressure resistant dry gas sealing device according to claim 1, characterized in that: The dynamic ring assembly includes a dynamic ring seat and a dynamic ring. The dynamic ring seat is fixed to the shaft sleeve, and a spring loading ring is provided between the dynamic ring seat and the shaft sleeve. The dynamic ring and the dynamic ring seat are fixed by a transmission pin. The tail end side of the dynamic ring abuts against the front end side of the stationary ring to form a first sealing surface.

8. The high pressure resistant dry gas sealing device according to claim 7, characterized in that: A micron-sized shallow groove is provided on the side surface of the tail end of the moving ring.

9. The high pressure resistant dry gas sealing device according to claim 7, characterized in that: The moving ring seat includes an outer seat, a connecting seat and an inner seat which are integrally formed and connected in sequence, the outer seat and the inner seat are parallel to the axial direction of the rotating shaft, the connecting seat is perpendicular to the axis of the rotating shaft, the moving ring is installed between the outer seat, the connecting seat and the inner seat, and a centering spring is provided on the inner seat, the centering spring abuts against the inner wall of the moving ring, and a spring loading ring is provided between the moving ring and the moving ring seat.

10. The high pressure resistant dry gas sealing device according to claim 9, characterized in that: A compression sleeve is fixed on the inner seat, a spring loading ring is arranged between the compression sleeve and the inner seat, and the front end of the compression sleeve abuts against the end surface of the tail end of the moving ring.

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