Radial double-end-face dry gas sealing structure

Abstract

The utility model discloses a radial double-end-face dry gas sealing structure which comprises a shaft sleeve, a rotating shaft, a spring seat, a spring, a push ring, a first floating sealing ring, a second floating sealing ring, a static ring and a rotating ring, the shaft sleeve is connected with the rotating shaft, the rotating ring is fixedly connected with the shaft sleeve, the spring seat is fixed on a cavity, and the spring is installed in a hole groove of the spring seat. The spring and the static ring are arranged on the two sides of the push ring respectively, the two ends of the push ring are each provided with an annular groove, the first floating sealing ring and the second floating sealing ring are arranged on the annular grooves in a sleeving mode respectively, the end face of the first floating sealing ring and the end face of the second floating sealing ring make close contact with the static ring and the spring seat respectively to form contact sealing, and the rotating ring is located on the side portion of the static ring. The rotating ring is tightly attached to the static ring. Two groups of dry gas sealing friction pairs are formed, radial double-end-face dry gas sealing is formed, the whole structure is compact, the size of the axial occupied space is small, leakage of process gas is prevented by introducing sealing gas, zero emission of process media can be guaranteed, and the problem of large leakage amount is solved.

Description

Technical Field

[0001] The utility model relates to the technical field of rotary machinery shaft end seals, in particular to a radial double-end surface dry gas seal structure. Background Art

[0002] Dry gas seal is a new type of non-contact gas lubrication seal. It uses the principle of fluid dynamics to achieve non-contact operation of the seal end face by opening a dynamic pressure groove on the seal end face. Due to its unique advantages, it has been widely used in various medium and high-speed rotating machinery, such as centrifugal compressors, turbines, fans, etc. The structural form of dry gas seal can be divided into single-end dry gas seal, double-end dry gas seal, and tandem dry gas seal according to the different sealed media and the different media pressures.

[0003] At present, double-end dry gas seals are composed of two sets of dry gas seals facing each other. The sealing gas is nitrogen. The medium gas is sealed by sealing the nitrogen. Conventional double-end dry gas seals use two sets of dry gas seals arranged axially face to face. This axially arranged double-end dry gas seal occupies a large axial space and has a large leakage.

[0004] In view of this, this patent application is filed. Utility Model Content

[0005] The utility model aims to provide a radial double-end dry gas seal structure to solve the above-mentioned problem that the existing double-end dry gas seal adopts face-to-face axial arrangement, resulting in large axial space occupation and large leakage.

[0006] The utility model is realized by the following technical solutions:

[0007] The utility model aims to provide a radial double-end face dry gas sealing structure, comprising a shaft sleeve, a rotating shaft, a spring seat, a spring, a push ring, a first floating sealing ring, a second floating sealing ring, a stationary ring, and a rotating ring, wherein the shaft sleeve is connected to the rotating shaft, the rotating ring is fixedly connected to the shaft sleeve, the spring seat is fixed on a cavity, the spring is installed in a hole groove of the spring seat, the two sides of the push ring are a spring and a stationary ring respectively, both ends of the push ring have an annular groove, the first floating sealing ring and the second floating sealing ring are respectively sleeved on the annular groove, the end faces of the first floating sealing ring and the second floating sealing ring are respectively in close contact with the stationary ring and the spring seat to form a contact seal, the rotating ring is located on the side of the stationary ring, and the rotating ring is closely matched with the stationary ring.

[0008] In an optional embodiment, the first floating sealing ring and the second floating sealing ring are both in contact sliding fit with the spring seat.

[0009] In an optional embodiment, the push ring and the stationary ring are both annular structures with a slot in the middle, and the central axis of the push ring coincides with the central axis of the stationary ring.

[0010] In an optional embodiment, the rotating ring and the sleeve are fixedly connected via a transmission pin.

[0011] In an optional embodiment, a sealing ring is provided between the rotating ring and the shaft sleeve, and a sealing ring is provided between the shaft sleeve and the rotating shaft.

[0012] In an optional embodiment, a support ring is further provided between the rotating ring and the sleeve.

[0013] In an optional embodiment, a clamping sleeve is provided on the side of the sleeve, the clamping sleeve is tightly fitted with the side of the rotating ring, and a locking nut is provided on the side of the clamping sleeve away from the sleeve, and the locking nut is fixedly connected to the rotating shaft.

[0014] In an optional embodiment, a snap ring is further provided on the spring seat, and the snap ring is located on a side of the spring seat opposite to the rotating ring;

[0015] The stationary ring is also provided with a limit block, and the limit block is located on a surface of the stationary ring opposite to the spring seat;

[0016] The spring seat is connected to the cavity through a first connecting screw, and the compression sleeve is connected to the shaft sleeve through a second connecting screw.

[0017] In an optional embodiment, two dynamic pressure grooves, an inner ring and an outer ring, are provided between the rotating ring and the stationary ring to form a non-contact tight fit, and the outer ring dynamic pressure groove and the inner ring dynamic pressure groove are respectively the dynamic pressure groove of the dry gas seal friction pair located at the upper part and the dynamic pressure groove of the dry gas seal friction pair located at the lower part;

[0018] The outer ring dynamic pressure groove and the inner ring dynamic pressure groove are both distributed circumferentially on the end surface of the rotating ring, and the outer ring dynamic pressure groove and the inner ring dynamic pressure groove have opposite rotation directions;

[0019] The end surface of the stationary ring is provided with a drainage groove and ventilation holes, the drainage groove is communicated with the ventilation holes, and the ventilation holes are arranged in a circumference.

[0020] In an optional embodiment, two of the stationary ring, the push ring, the first floating seal ring, the second floating seal ring, the push ring, and the spring are symmetrically arranged relative to the rotating ring.

[0021] The advantages and beneficial effects of the utility model compared to the prior art are:

[0022] The embodiment of the utility model provides a radial double-end dry gas seal structure, which forms two sets of dry gas seal friction pairs located at upper and lower positions, and the two sets of friction pairs are arranged radially to form the radial double-end dry gas seal of the utility model. The overall structure is compact and the size of the axial space occupied is small, which is particularly suitable for installation and use of equipment with small axial size requirements; and relying on the introduction of sealing gas to prevent process gas leakage, it can ensure zero discharge of process media and solve the problem of large leakage. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the technical solutions of the exemplary embodiments of the present utility model, the following is a brief introduction to the drawings required for use in the embodiments. It should be understood that the following drawings only illustrate certain embodiments of the present utility model, and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without creative work. In the drawings:

[0024] Figure 1 A schematic diagram of a radial double-end surface dry gas seal structure provided in one embodiment of the utility model.

[0025] Figure 2 It is a schematic diagram of the structure of two radial double-end surface dynamic pressure grooves formed between the rotating ring and the stationary ring.

[0026] Figure 3 It is a schematic diagram of the structure of the drainage groove and the vent hole arranged on the stationary ring.

[0027] Figure 4 This is a schematic diagram of the enlarged structure of the vent holes on the stationary ring.

[0028] Figure 5 for Figure 2 Middle along AA direction, Figure 3 A schematic diagram of the structure in which the dynamic pressure groove formed after sectioning along the BB direction cooperates with the drainage groove and the vent hole.

[0029] Figure 6 is the flow direction of the dry gas seal gas between the rotating ring and the stationary ring;

[0030] Figure 7 It is a schematic structural diagram of a counterclockwise rotating dynamic pressure groove of a radial double-end surface dry gas seal according to an embodiment of the present invention.

[0031] Figure 8 This is a schematic diagram of the double-stage radial double-end dry gas seal structure in Example 3.

[0032] Marks and corresponding parts names in the attached drawings:

[0033] 1-rotating shaft; 2-sleeve; 3-rotating ring; 4-stationary ring; 5-spring seat; 6-spring; 7-push ring; 8.1-first floating sealing ring; 8.2-second floating sealing ring; 9-pressure sleeve; 10-locking nut; 11-first connecting screw; 12-second connecting screw; 13-circuit ring; 14-limiting block; 15-transmission pin; 16-sealing ring; 17-support ring; 18-cavity, 19-outer ring dynamic pressure groove, 20-inner ring dynamic pressure groove, 21-drainage groove, 22-vent. DETAILED DESCRIPTION

[0034] In order to make the purpose, technical solutions and advantages of the utility model more clearly understood, the utility model is further described in detail below in conjunction with embodiments and drawings. The schematic implementation manner of the utility model and its description are only used to explain the utility model and are not intended to limit the utility model.

[0035] In the following description, a large number of specific details are set forth in order to provide a thorough understanding of the present invention. However, it is apparent to those skilled in the art that these specific details are not necessary to implement the present invention. In other embodiments, in order to avoid confusing the present invention, well-known structures, circuits, materials or methods are not specifically described.

[0036] Throughout the specification, references to "one embodiment," "an embodiment," "an example," or "an example" mean that a particular feature, structure, or characteristic described in conjunction with the embodiment or example is included in at least one embodiment of the present invention. Therefore, the phrases "one embodiment," "an embodiment," "an example," or "an example" appearing in various places throughout the specification do not necessarily all refer to the same embodiment or example. In addition, particular features, structures, or characteristics may be combined in one or more embodiments or examples in any suitable combination and / or sub-combination. In addition, it will be appreciated by those of ordinary skill in the art that the figures provided herein are for illustrative purposes and that the figures are not necessarily drawn to scale. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0037] In the description of the present invention, the terms "front", "rear", "left", "right", "up", "down", "vertical", "horizontal", "high", "low", "inside", "outside", etc. indicate directions or positional relationships based on the directions or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction. Therefore, they should not be understood as limiting the scope of protection of the present invention.

[0038] like Figure 1As shown in the figure, a radial double-end face dry gas seal structure includes a sleeve 2, a rotating shaft 1, a spring seat 5, a spring 6, a push ring 7, a first floating seal ring 8.1, a second floating seal ring 8.2, a stationary ring 4, and a rotating ring 3.

[0039] Among them, the structure of this embodiment uses the rotating shaft 1 as the rotating shaft, and the sleeve 2 is connected to the rotating shaft 1. The rotating ring 3 is fixedly connected to the sleeve 2. The dry gas sealing structure of this embodiment uses the spring seat 5 as the base, and the spring seat 5 is fixed on the cavity 18 and connected by the first connecting screw 11. A hole groove is provided on the inner side of the spring seat 5, and the spring 6 is installed in the hole groove of the spring seat 5. The two sides of the push ring 7 are the spring 6 and the stationary ring 4 respectively, and the two ends of the push ring 7 are provided with a ring groove. The first floating seal ring 8.1 and the second floating seal ring 8.2 are respectively sleeved on the ring grooves. The two end surfaces of the first floating seal ring 8.1 and the second floating seal ring 8.2 away from the ring groove are in close contact with the stationary ring 4 and the spring 6 respectively. The rotating ring 3 is located on the side of the stationary ring 4. The rotating ring 3 and the stationary ring 4 are closely matched, so that the spring 6, the push ring 7, the floating seal ring 16, and the stationary ring 4 are arranged closely in sequence and assembled together in the spring seat 5 to form a contact seal.

[0040] In this way, the dry gas sealing structure of this embodiment forms two groups of dry gas sealing friction pairs. The first dry gas sealing friction pair is formed by the upper half of the stationary ring 4, the upper half of the rotating ring 3, the first floating sealing ring 8.1, and the upper half of the push ring 7. The second dry gas sealing friction pair is formed by the lower half of the stationary ring 4, the lower half of the rotating ring 3, the second floating sealing ring 8.2, and the lower half of the push ring 7. The two groups of friction pairs are arranged radially to form a radial double-end face dry gas seal of the utility model.

[0041] The dry gas sealing structure in this embodiment has a compact structure and a small axial space, and is particularly suitable for installation and use in equipment that requires small axial dimensions. In addition, the dry gas sealing structure in this embodiment relies on the introduction of sealing gas to prevent process gas leakage, which can ensure zero discharge of process media and solve the problem of large leakage.

[0042] Furthermore, the first floating sealing ring 8.1 and the second floating sealing ring 8.2 are both in contact sliding cooperation with the spring seat 5, so that the floating sealing ring 16 and the spring seat 5 can slide relative to each other to compensate for the small movement of the stationary ring 4 during the operation of the dry gas seal. Under the effect of a certain interference fit of the floating sealing ring 16, excessive friction will not be generated during the movement to affect the dry gas sealing performance, and good sealing can be ensured.

[0043] Furthermore, the push ring 7 and the stationary ring 4 are both annular structures with a slot in the middle, and the central axis of the push ring 7 coincides with the central axis of the stationary ring 4, so that the rotating ring 3, the stationary ring 4, the first floating sealing ring 8.1, the second floating sealing ring 8.2, the push ring 7 and the spring 6 form a radially symmetrical structure. This balanced design can minimize the axial force generated by the dry gas seal and reduce the influence of the dry gas seal on the rotating shaft 1.

[0044] Furthermore, the rotating ring 3 and the shaft sleeve 2 are fixedly connected via a transmission pin 15, so that the two are tightly and firmly connected.

[0045] Furthermore, a sealing ring 16 is provided between the rotating ring 3 and the sleeve 2, and a sealing ring 16 is provided between the sleeve 2 and the rotating shaft 1. The purpose of providing the sealing ring 16 at these two locations is to further enhance the sealing reliability of the entire dry gas sealing structure and avoid leakage of the gas medium during the rotation process. A sealing ring 16 is also provided between the spring seat 5 and the cavity 18.

[0046] A support ring 17 is further provided between the rotating ring 3 and the shaft sleeve 2 , and the supporting ring 17 is used to radially position the rotating ring 3 .

[0047] Furthermore, a compression sleeve 9 is provided on the side of the sleeve 2, and the compression sleeve 9 is tightly fitted with the side of the rotating ring 3. A locking nut 10 is provided on the side of the compression sleeve 9 away from the sleeve 2, and the locking nut 10 is fixedly connected to the rotating shaft 1. The compression sleeve 9 and the sleeve 2 are connected by a second connecting screw 12.

[0048] In this embodiment, the rotating ring 3 and the support ring 17 are installed on the sleeve 2, and the clamping sleeve 9 and the rotating ring 3 are axially fixed by the second connecting screw 12; the locking nut 10 presses the sleeve 2 and the clamping sleeve 9 on the rotating shaft 1 to realize the compression transmission between the sleeve 2, the rotating ring 3 and the clamping sleeve 9.

[0049] Embodiment 2:

[0050] On the basis of Example 1, Figure 1 As shown in , the spring seat 5 is further provided with a snap ring 13, and the snap ring 13 is located on the side of the spring seat 5 opposite to the rotating ring 3. The stationary ring 4 is further provided with a limit block 14, and the limit block 14 is located on the side of the stationary ring 4 opposite to the spring seat 5. The provision of the snap ring 13 and the limit block 14 can provide a limit function for the installation of the rotating ring 3 and the stationary ring 4, so that a suitable spacing is formed between the end face of the spring seat 5 and the surface of the stationary ring 4.

[0051] Embodiment 3:

[0052] On the basis of Example 1 or Example 2, in order to improve the sealing reliability and service life of the sealing structure, it is further provided that the rotating ring 3 and the stationary ring 4 are closely matched with each other in a non-contact manner.

[0053] Specifically, Figures 2 to 6 As shown in , an outer ring dynamic pressure groove 19 and an inner ring dynamic pressure groove 20 are provided between the rotating ring 3 and the stationary ring 4. The outer ring dynamic pressure groove 19 serves as the dynamic pressure groove of the upper dry gas seal friction pair (i.e., the first dry gas seal friction pair mentioned above), and the inner ring dynamic pressure groove 20 serves as the dynamic pressure groove of the lower dry gas seal friction pair (i.e., the second dry gas seal friction pair mentioned above). The outer ring dynamic pressure groove 19 and the inner ring dynamic pressure groove 20 are both engraved on the end face of the rotating ring 3 by laser processing, and the outer ring dynamic pressure groove 19 and the inner ring dynamic pressure groove 20 are evenly distributed on the circumference of the rotating ring 3. The depth of laser processing is 6 to 8 μm, and the number is 12 respectively. The outer ring dynamic pressure groove 19 and the inner ring dynamic pressure groove 20 have opposite rotation directions. The two groups of dynamic pressure grooves together constitute the dynamic pressure grooves of the radial double-end face dry gas seal.

[0054] A drainage groove 21 and ventilation holes 22 are designed on the end surface of the stationary ring 4 . Twelve ventilation holes 22 are evenly distributed around the circumference, and the ventilation holes 22 are connected to the drainage groove 21 .

[0055] The working principle is as follows: when the radial double-end dry gas seal works normally, the sealing gas is introduced from the vent hole 22, and the sealing gas enters the drainage groove 21. Under the action of the dynamic pressure of the dynamic pressure groove fluid, the sealing gas is pumped into the outer ring dynamic pressure groove 19 and the inner ring dynamic pressure groove 20 in two directions, generating a dynamic pressure effect, blocking the outer or inner sealing medium from entering the sealing end face, playing a sealing role. At the same time, an air film is formed on the end faces of the rotating ring 3 and the stationary ring 4, so that the end faces of the rotating ring 3 and the stationary ring 4 are disengaged, realizing non-contact operation and improving the sealing reliability and service life. The gas flow direction is as follows: Figure 6 shown.

[0056] The dynamic pressure groove can also be designed as a counterclockwise rotating dynamic pressure groove as needed, such as Figure 7 shown.

[0057] Embodiment 3:

[0058] On the basis of Example 1 or Example 2, the dry gas seal structure can be further designed as a double-stage radial double-end dry gas seal, as shown in FIG. Figure 3 As shown in the figure, with the rotating ring 3 as the center, two stationary rings 4, a push ring 7, a first floating seal ring 8.1, a second floating seal ring 8.2, a push ring 7 and a spring 6 can be arranged. The reliability of the radial double end face seal is further improved, and the practicality is stronger.

[0059] The radial double-end-face dry gas seal provided by the embodiment of the utility model has the characteristics of compact structure and small axial size, and is particularly suitable for installation and use in equipment with small axial size requirements.

[0060] The radial double-end face dry gas seal of the utility model adopts a balanced design, which can reduce the axial force generated by the dry gas seal to the greatest extent and reduce the influence of the dry gas seal on the rotating shaft 1.

[0061] The radial double-end-face dry gas seal of the utility model relies on the introduction of sealing gas to prevent leakage of process gas, thereby ensuring zero discharge of process medium.

[0062] The radial double-end-face dry gas seal of the utility model operates in a non-contact manner and has the characteristics of high reliability and long service life.

[0063] The above specific implementation methods further illustrate the purpose, technical solutions and beneficial effects of the utility model in detail. It should be understood that the above are only specific implementation methods of the utility model and are not used to limit the protection scope of the utility model. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the utility model should be included in the protection scope of the utility model.

Claims

1. A radial double-end dry gas seal structure, characterized in that: The invention comprises a shaft sleeve (2), a rotating shaft (1), a spring seat (5), a spring (6), a push ring (7), a first floating seal ring (8.1), a second floating seal ring (8.2), a stationary ring (4), and a rotating ring (3), wherein the shaft sleeve (2) is connected to the rotating shaft (1), the rotating ring (3) is fixedly connected to the shaft sleeve (2), the spring seat (5) is fixed on the cavity (18), the spring (6) is installed in the hole groove of the spring seat (5), and the two sides of the push ring (7) are respectively (6) and a stationary ring (4), both ends of the push ring (7) are provided with an annular groove, the first floating seal ring (8.1) and the second floating seal ring (8.2) are respectively sleeved on the annular grooves, the end faces of the first floating seal ring (8.1) and the second floating seal ring (8.2) are respectively in close contact with the stationary ring (4) and the spring seat (5) to form a contact seal, the rotating ring (3) is located on the side of the stationary ring (4), and the rotating ring (3) and the stationary ring (4) are in close fit.

2. A radial double-end dry gas seal structure according to claim 1, characterized in that: The first floating sealing ring (8.1) and the second floating sealing ring (8.2) are both in contact-type sliding cooperation with the spring seat (5).

3. A radial double-end dry gas seal structure according to claim 2, characterized in that: The push ring (7) and the stationary ring (4) are both annular structures with a slotted hole in the middle, and the central axis of the push ring (7) coincides with the central axis of the stationary ring (4).

4. A radial double-end dry gas seal structure according to claim 3, characterized in that: The rotating ring (3) and the shaft sleeve (2) are fixedly connected via a transmission pin (15).

5. A radial double-end dry gas seal structure according to claim 4, characterized in that: A sealing ring (16) is provided between the rotating ring (3) and the shaft sleeve (2), and a sealing ring (16) is provided between the shaft sleeve (2) and the rotating shaft (1).

6. A radial double-end dry gas seal structure according to claim 5, characterized in that: A support ring (17) is also provided between the rotating ring (3) and the shaft sleeve (2).

7. A radial double-end dry gas seal structure according to claim 6, characterized in that: A compression sleeve (9) is provided on the side of the shaft sleeve (2), and the compression sleeve (9) is tightly fitted with the side of the rotating ring (3). A locking nut (10) is provided on the side of the compression sleeve (9) away from the shaft sleeve (2), and the locking nut (10) is fixedly connected to the rotating shaft (1).

8. A radial double-end dry gas seal structure according to claim 7, characterized in that: The spring seat (5) is also provided with a snap ring (13), and the snap ring (13) is located on a surface of the spring seat (5) opposite to the rotating ring (3); The stationary ring (4) is also provided with a limit block (14), and the limit block (14) is located on the side of the stationary ring (4) opposite to the spring seat (5); the spring seat (5) and the cavity (18) are connected by a first connecting screw (11), and the clamping sleeve (9) and the shaft sleeve (2) are connected by a second connecting screw (12).

9. A radial double-end dry gas seal structure according to any one of claims 1 to 8, characterized in that: Two dynamic pressure grooves, an inner ring and an outer ring, are provided between the rotating ring (3) and the stationary ring (4) to form a non-contact tight fit, wherein the outer ring dynamic pressure groove (19) and the inner ring dynamic pressure groove (20) are respectively the dynamic pressure groove of the dry gas seal friction pair located at the upper part and the dynamic pressure groove of the dry gas seal friction pair located at the lower part; The outer ring dynamic pressure groove (19) and the inner ring dynamic pressure groove (20) are both distributed in a circumferential manner on the end surface of the rotating ring (3), and the outer ring dynamic pressure groove and the inner ring dynamic pressure groove have opposite rotation directions; The end surface of the stationary ring (4) is provided with a drainage groove (21) and a vent hole (22); the drainage groove (21) is communicated with the vent hole (22); and the vent holes (22) are arranged in a circumference.

10. A radial double-end dry gas seal structure according to any one of claims 1 to 8, characterized in that: The stationary ring (4), the push ring (7), the first floating seal ring (8.1), the second floating seal ring (8.2), the push ring (7), and the spring (6) are all symmetrically arranged in pairs relative to the rotating ring (3).

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