A hybrid dry gas seal structure

Abstract

The present invention discloses a hybrid dry gas sealing structure, which relates to the field of dry gas sealing technology; it comprises a static ring body and a dynamic ring body, wherein the working end face of the dynamic ring body is provided with a plurality of dynamic pressure grooves, and the static ring body is provided with an air supply channel, the outlet of the air supply channel being located on the moving path of the dynamic pressure grooves. The present invention can output the sealing gas from the working end face of the static ring body to provide static pressure for the dynamic ring, and then, when the rotating shaft is stationary or the rotation speed is low, the end faces of the dynamic ring and the static ring that are in contact with each other are pushed open, ensuring that the end faces of the dry gas seal can be opened normally, avoiding contact between the working end faces of the dynamic ring and the static ring during operation, and when the rotating shaft of the equipment rotates, dynamic pressure and static pressure can be generated simultaneously through the dynamic pressure grooves provided on the dynamic ring, thereby ensuring that the sealing gas film between the static ring body and the dynamic ring body has sufficient rigidity and ensuring the stability of the dry gas seal operation. Therefore, the dry gas sealing structure provided by the present invention can be applied to low-speed equipment.

Description

Technical Field

[0001] The present invention relates to the technical field of dry gas sealing, and in particular to a hybrid dry gas sealing structure. Background Art

[0002] Dry gas seal is a non-contact gas lubricated seal. It uses the principles of fluid dynamics. After the sealing gas is introduced into the sealing structure, the sealing gas forms a stable gas film between the sealing end faces, thereby enabling the seal to operate non-contact. The prerequisite for maintaining the stability of the gas film is that the end face opening force and closing force are balanced. The closing force comes from the spring force and the medium pressure, and the opening force comes from the end face dynamic pressure.

[0003] Existing dry gas seals feature dynamic pressure grooves on the end faces of either the rotating or stationary ring. As the sealed shaft rotates, sealing gas is drawn into the grooves and flows from the outer diameter toward the center, with the radial component flowing toward the sealing weir. Therefore, the rotational speed plays a decisive role in determining the dynamic pressure of the dry gas seal. Consequently, in low-speed environments or when the equipment is stationary, the dynamic pressure effect on the seal end face is limited. This means the seal end face cannot open properly, and the static and rotating ring end faces will come into contact during operation, leading to seal failure. This limits the application of dry gas seals in low-speed applications. Summary of the Invention

[0004] In response to the technical problem that existing dry gas seals cannot be applied to low-speed fields, the present invention provides a hybrid dry gas sealing structure, in which an air outlet is arranged on the working end face of the static ring body, which can provide static pressure for the dynamic ring body to push open the end faces of the dynamic ring body and the static ring body that are in contact with each other, and provide dynamic pressure when the dynamic ring body rotates, ensuring that the sealing gas film has sufficient rigidity, so that the dry sealing structure can be applied to low-speed equipment.

[0005] The present invention is achieved through the following technical solutions:

[0006] The present invention provides a hybrid dry gas sealing structure, comprising a static ring body and a dynamic ring body, wherein the working end surface of the dynamic ring body is provided with a plurality of dynamic pressure grooves, and the static ring body is provided with an air supply channel, the outlet of the air supply channel is located on the moving path of the dynamic pressure grooves.

[0007] When the dry gas sealing structure provided by the present invention is in use, the high-pressure gas in the dry gas sealing system is connected to the air supply channel to be output from the working end face of the static ring body to provide static pressure for the dynamic ring. Then, when the rotating shaft is stationary or the speed is low, the end faces of the dynamic ring and the static ring that are in contact with each other are pushed open to ensure that the end faces of the dry gas seal can be opened normally, thereby avoiding contact between the working end faces of the dynamic ring and the static ring during operation.

[0008] Among them, when the rotating shaft of the equipment rotates, dynamic pressure and static pressure can be generated simultaneously through the dynamic pressure groove set on the dynamic ring, thereby ensuring that the sealing air film between the static ring body and the dynamic ring body has sufficient rigidity and ensuring the stability of the dry gas sealing operation. Therefore, the dry gas sealing structure provided by the present invention can be used in low-speed equipment.

[0009] In an optional embodiment, the stationary ring body is further provided with a first exhaust channel, the inlet of the first exhaust channel is located at the working end face of the stationary ring body, and the outlet of the first exhaust channel is located at the side wall or the mounting end face of the stationary ring body. The sealing leakage gas can be discharged through the first exhaust channel to facilitate the collection of the sealing leakage gas, and at the same time, it can prevent the sealing gas from entering the medium in large quantities and affecting the composition of the medium.

[0010] In an optional embodiment, in the diameter direction of the static ring body, the outlet of the first exhaust channel is located on the inner side of the outlet of the air supply channel, so as to introduce the sealing gas leaking to the rotating shaft into the first exhaust channel, thereby minimizing the amount of sealing gas entering the medium.

[0011] In an optional embodiment, the working end face of the stationary ring body is further provided with a sunken exhaust step; in the diameter direction of the stationary ring body, the exhaust step is located on the inner side of the outlet of the first exhaust channel and the outlet of the air supply channel to reduce the size of the contact surface between the stationary ring body and the dynamic ring body.

[0012] In an optional embodiment, a stationary ring seat is further included, and the stationary ring body is sealingly inserted in the stationary ring seat; the stationary ring seat is provided with an air inlet channel, and the air inlet channel is connected to the air supply channel. Compared with directly inputting gas into the air supply channel, there is no need to thicken the stationary ring body, and the thickness of the stationary ring body can be reduced, thereby reducing the axial length of the dry gas sealing structure.

[0013] In an optional embodiment, the stationary ring seat is provided with a second exhaust channel, and the second exhaust channel is communicated with the first exhaust channel, so as to discharge the sealing leakage gas through the second exhaust channel on the stationary ring seat.

[0014] In an optional embodiment, the dynamic pressure groove is a sunken groove to prevent a large amount of sealing gas from leaking from the side wall of the dynamic ring body.

[0015] In an optional embodiment, it also includes a dynamic ring seat, which is provided with a mounting groove; the dynamic ring body is sealed and inserted in the mounting groove, and the dynamic ring body can move along its own axis; a compression spring is provided between the mounting end face of the dynamic ring body and the bottom of the mounting groove, which can reduce the size of the gap between the static ring body and the static ring mounting seat and avoid the sealing gas from being discharged from the second exhaust channel compared to directly applying the spring force to the static ring body through the compression spring.

[0016] In an optional embodiment, the dynamic ring seat is provided with a limit block, and the limit block is located at the notch of the installation groove to limit the dynamic ring body within the installation groove.

[0017] In an optional embodiment, a damping portion is provided in the air supply channel, and a damping hole connected to the air supply channel is provided in the damping portion, so that the pressure and flow of the gas entering the sealing surface can be controlled by controlling the size of the damping hole.

[0018] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0019] The working end face of the dynamic ring body of the present invention is provided with a plurality of dynamic pressure grooves, and the static ring body is provided with an air supply channel. The outlet of the air supply channel is located on the moving path of the dynamic pressure groove, so that the sealing gas can be output from the working end face of the static ring body to provide static pressure for the dynamic ring. Then, when the rotating shaft is stationary or the rotation speed is low, the end faces of the dynamic ring and the static ring that are in contact with each other are pushed open to ensure that the end faces of the dry gas seal can be opened normally, avoiding contact between the working end faces of the dynamic ring and the static ring during operation. Moreover, when the rotating shaft of the equipment rotates, dynamic pressure and static pressure can be generated simultaneously through the dynamic pressure grooves provided on the dynamic ring, thereby ensuring that the sealing air film between the static ring body and the dynamic ring body has sufficient rigidity and ensuring the stability of the dry gas seal operation. Therefore, the dry gas sealing structure provided by the present invention can be used in low-speed equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following is a brief introduction to the drawings required for use in the embodiments. It should be understood that the following drawings only show certain embodiments of the present application 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.

[0021] In the attached figure:

[0022] Figure 1 This is a schematic structural diagram of a dry gas sealing structure according to an embodiment of the present invention;

[0023] Figure 2 This is a schematic structural diagram of the joint between the dynamic ring body and the static ring body of the dry gas seal structure according to an embodiment of the present invention;

[0024] Figure 3 This is a schematic diagram of the working end surface structure of the dynamic ring body according to an embodiment of the present invention;

[0025] Figure 4 for Figure 1 A magnified schematic diagram of part A.

[0026] Markings and corresponding parts names in the accompanying drawings:

[0027] 10-static ring body, 11-air supply channel, 12-first exhaust channel, 13-exhaust step, 14-damping part;

[0028] 20-stationary ring seat, 21-intake channel, 22-second exhaust channel;

[0029] 30-dynamic ring body, 31-dynamic pressure groove;

[0030] 40-dynamic ring seat, 41-mounting groove, 42-compression spring, 43-guide pin, 44-limiting block, 45-positioning block;

[0031] 50-Rotation axis. DETAILED DESCRIPTION

[0032] To make the objectives, technical solutions, and advantages of the embodiments of the present application more clear, the technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the accompanying drawings of the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Generally, the components of the embodiments of the present application described and shown in the drawings herein can be arranged and designed in various different configurations.

[0033] It should be noted that similar reference numerals and letters represent similar items in the following figures. Therefore, once an item is defined in one figure, it does not need to be further defined or explained in subsequent figures. In the absence of conflict, the embodiments and features in the embodiments of this application can be combined with each other.

[0034] In the description of the embodiments of the present application, the terms "center", "up", "down", "left", "right", "vertical", "longitudinal", "lateral", "horizontal", "inside", "outside", "front", "back", "top", "bottom", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, or are the orientations or positional relationships in which the product of the application is conventionally placed when in use, or are the orientations or positional relationships conventionally understood by those skilled in the art. They are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0035] In the description of the present invention, unless otherwise expressly specified or limited, the terms "disposed," "having," "installed," "connected," and "connected" should be understood in a broad sense. For example, they may refer to fixed, detachable, or integral connections; mechanical or electrical connections; direct or indirect connections through an intermediate medium; and internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention in specific contexts.

[0036] Example 1

[0037] Combine Figure 1 and Figure 2 This embodiment provides a hybrid dry gas sealing structure, including a static ring body 10 and a dynamic ring body 30, the working end face of the dynamic ring body 30 is provided with a plurality of dynamic pressure grooves 31, and the static ring body 10 is provided with an air supply channel 11, the outlet of the air supply channel 11 is located on the moving path of the dynamic pressure groove 31.

[0038] Combine Figure 3 The dynamic pressure groove 31 is a sunken groove, that is, the dynamic pressure groove 31 is a groove closed on all sides to prevent a large amount of sealing gas from leaking from the side wall of the dynamic ring body.

[0039] It is understood that when the dry gas seal structure is in use, the stationary ring body 10 is tightly pressed against the dynamic ring body 30. Therefore, the end surface of the stationary ring body 10 in contact with the dynamic ring body 30 is the working end surface of the stationary ring body 10, and the other end surface of the stationary ring body 10 is the mounting end surface of the stationary ring body 10. Correspondingly, the end surface of the dynamic ring body 30 in contact with the stationary ring body 10 is the working end surface of the dynamic ring body 30, and the other end surface of the dynamic ring body 30 is the mounting end surface of the dynamic ring body 30.

[0040] The outlet of the air supply channel 11 is located on the movement path of the dynamic pressure groove 31, so that when the dynamic ring body 30 rotates, the sealing gas output from the air supply channel 11 can directly enter the dynamic pressure groove 31 to generate dynamic pressure. The inlet position of the air supply channel 11 is determined based on the installation conditions of the static ring body 10. If there is ample space on the side wall of the static ring body 10, the inlet of the air supply channel 11 can be set on the side wall of the static ring body 10. Otherwise, the inlet of the air supply channel 11 can be set on the mounting end surface of the static ring body 10. By providing an air inlet channel 21 on the static ring mounting seat, the sealing gas can be input into the air supply channel 11.

[0041] When the dry gas sealing structure provided in this embodiment is in use, the high-pressure gas in the dry gas sealing system is connected to the gas supply channel 11 to be output from the working end face of the static ring body 10 to provide static pressure for the dynamic ring body 30. Then, when the rotating shaft is stationary or the rotation speed is low, the end faces of the dynamic ring body 30 and the static ring body 10 that are in contact with each other are pushed open to ensure that the end faces of the dry gas seal can be opened normally, thereby avoiding contact between the working end faces of the dynamic ring and the static ring during operation.

[0042] When the device's shaft rotates, the dynamic pressure grooves 31 on the dynamic ring simultaneously generate dynamic and static pressure, ensuring sufficient rigidity of the sealing air film between the static ring body 10 and the dynamic ring body 30, ensuring the stability of dry gas sealing operation. Therefore, this design can be directly applied to low-speed equipment.

[0043] Example 2

[0044] Combine Figure 1 and Figure 2 This embodiment provides a hybrid dry gas sealing structure. Based on the structure and principle described in Example 1, the static ring body 10 is further provided with a first exhaust channel 12. The inlet of the first exhaust channel 12 is located at the working end face of the static ring body 10, and the outlet of the first exhaust channel 12 is located at the side wall or the installation end face of the static ring body 10. The sealing leakage gas can be discharged through the first exhaust channel 12 to facilitate the collection of the sealing leakage gas, while preventing a large amount of sealing gas from entering the medium and affecting the composition of the medium.

[0045] Similarly, the outlet position of the first exhaust channel 12 is determined according to the installation situation of the static ring body 10. If the space on the side wall of the static ring body 10 is relatively ample, the outlet of the first exhaust channel 12 can be set on the side wall of the static ring body 10. Otherwise, the outlet of the first exhaust channel 12 can be set on the installation end face of the static ring body 10, so as to output the sealed leakage gas by setting a corresponding exhaust channel on the static ring mounting seat.

[0046] Optionally, in the diameter direction of the static ring body 10, the outlet of the first exhaust channel 12 is located on the inner side of the outlet of the air supply channel 11, so as to introduce the sealing gas leaking to the rotating shaft into the first exhaust channel 12, thereby minimizing the amount of sealing gas entering the medium.

[0047] Example 3

[0048] Combine Figure 1 and Figure 2This embodiment provides a hybrid dry gas sealing structure, which is a specific implementation of Example 1 and Example 2, and also includes a static ring seat 20, in which the static ring body 10 is sealed and inserted; the static ring seat 20 is provided with an air inlet channel 21, and the air inlet channel 21 is connected to the air supply channel 11.

[0049] Continue to combine Figure 1 In this embodiment, the inlet of the air supply channel 11 is located on the mounting end surface of the static ring body 10, and the outlet of the air inlet channel 21 is located on the end surface of the static ring seat 20 on which the static ring body 10 is mounted. In addition, under normal circumstances, the inlet of the air supply channel 11 is opposite to the outlet of the air inlet channel 21. Compared with directly inputting gas into the air supply channel 11, there is no need to thicken the static ring body 10, and the thickness of the static ring body 10 can be reduced, thereby reducing the axial length of the dry gas sealing structure.

[0050] On this basis, the stationary ring seat 20 is provided with a second exhaust channel 22, which is connected to the first exhaust channel 12 to discharge the sealing leakage gas through the second exhaust channel 22 on the stationary ring seat 20. Similarly, the outlet of the first exhaust channel 12 is located on the mounting end surface of the stationary ring body 10, and the inlet of the second exhaust channel 22 is located on the end surface of the stationary ring seat 20 to which the stationary ring body 10 is mounted. Generally, the outlet of the first exhaust channel 12 is directly opposite the inlet of the second exhaust channel 22.

[0051] It should be understood that in order to prevent the gas output from the air inlet channel 21 from entering the second exhaust channel 22 through the gap between the static ring body 10 and the static ring seat 20, a first sealing ring is provided between the mounting end face of the static ring body 10 and the static ring seat 20, and the air supply channel 11 and the first exhaust channel 12 are respectively provided on the inner and outer sides of the first sealing ring.

[0052] Correspondingly, it also includes a dynamic ring seat 40, which is provided with a mounting groove 41; the dynamic ring body 30 is sealed and inserted in the mounting groove 41, and the dynamic ring body 30 can move along its own axis; a compression spring 42 is provided between the mounting end surface of the dynamic ring body 30 and the bottom of the mounting groove 41. Compared with directly applying the spring force to the static ring body 10 through the compression spring 42, the size of the gap between the static ring body 10 and the static ring mounting seat can be reduced and the sealing gas can be prevented from being discharged from the second exhaust channel 22.

[0053] In order to prevent the dynamic ring body 30 from getting stuck when floating, a guide pin 43 is axially provided in the mounting groove 41. The guide pin 43 is fixedly connected to the dynamic ring seat 40. At the same time, a pin hole with an inner diameter larger than the outer diameter of the guide pin 43 is provided on the mounting end face of the dynamic ring body 30 so that the guide pin 43 can be inserted into the pin hole.

[0054] In addition, the dynamic ring seat 40 is provided with a limit block 44, which is located at the notch of the mounting groove 41 to confine the dynamic ring body 30 within the mounting groove 41. To ensure the relative position of the dynamic ring seat 40 and the static ring seat 20, a positioning block 45 is provided on the dynamic ring seat 40, and the positioning block 45 is fixedly connected to both the dynamic ring seat 40 and the static ring seat 20.

[0055] Example 4

[0056] Combine Figure 2 This embodiment provides a hybrid dry gas sealing structure. Based on the structure and principle described in Example 3, the working end face of the static ring body 10 is also provided with a sunken exhaust step 13; in the diameter direction of the static ring body 10, the exhaust step 13 is located on the inner side of the outlet of the first exhaust channel 12 and the outlet of the air supply channel 11, so as to reduce the size of the contact surface between the static ring body 10 and the dynamic ring body 30.

[0057] It should be noted that the sealing air film between the dynamic ring body 30 and the static ring body 10 is typically approximately 3 microns thick, and the corresponding amount of depression of the exhaust step 13 is less than 3 microns. The exhaust step 13 is the area where the sealing gas exits and contacts the medium. The sealing gas pressure is always slightly greater than the medium pressure, preventing the medium from leaking into the atmosphere. Furthermore, the presence of the exhaust step 13 ensures that the end faces of the dynamic ring body 30 and the static ring body 10 do not contact each other, even when only a small amount of gas passes through this area.

[0058] Example 5

[0059] Combine Figure 4 This embodiment provides a hybrid dry gas sealing structure. Based on the structure and principle described in any one of Embodiments 1 to 4, a damping portion 14 is provided in the gas supply channel 11. The damping portion 14 is provided with a damping hole connected to the gas supply channel 11. The damping portion 14 plays the role of reducing pressure and limiting flow, so as to control the pressure and flow of the gas entering the sealing surface by controlling the size of the damping hole.

[0060] In order to facilitate replacement of the damping part 14 with different apertures, the damping part 14 is made into a ring shape, and a stepped hole adapted to the damping part 14 is provided at the inlet of the air supply channel 11 , and the damping part 14 can be directly placed in the stepped hole.

[0061] The specific implementation methods described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific implementation method of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A hybrid dry gas seal structure, comprising a static ring body (10) and a dynamic ring body (30), wherein a plurality of dynamic pressure grooves (31) are provided on a working end surface of the dynamic ring body (30), characterized in that: The stationary ring body (10) is provided with an air supply channel (11), and the outlet of the air supply channel (11) is located on the moving path of the dynamic pressure groove (31); The stationary ring body (10) is further provided with a first exhaust channel (12), the inlet of the first exhaust channel (12) is located on the working end face of the stationary ring body (10), and the outlet of the first exhaust channel (12) is located on the side wall or the mounting end face of the stationary ring body (10); The working end surface of the stationary ring body (10) is further provided with a sunken exhaust step (13); In the diameter direction of the stationary ring body (10), the exhaust step (13) is located on the inner side of the outlet of the first exhaust channel (12) and the outlet of the air supply channel (11).

2. The hybrid dry gas seal structure according to claim 1, characterized in that: In the diameter direction of the stationary ring body (10), the outlet of the first exhaust channel (12) is located on the inner side of the outlet of the air supply channel (11).

3. The hybrid dry gas seal structure according to claim 1, characterized in that: It also includes a stationary ring seat (20), wherein the stationary ring body (10) is sealingly inserted into the stationary ring seat (20); The stationary ring seat (20) is provided with an air inlet channel (21), and the air inlet channel (21) is in communication with the air supply channel (11).

4. The hybrid dry gas seal structure according to claim 3, characterized in that: The stationary ring seat (20) is provided with a second exhaust channel (22), and the second exhaust channel (22) is communicated with the first exhaust channel (12).

5. The dry gas sealing structure according to claim 1, characterized in that: The dynamic pressure groove (31) is a sunken groove.

6. The dry gas sealing structure according to claim 5, characterized in that: It also includes a dynamic ring seat (40), wherein the dynamic ring seat (40) is provided with a mounting groove (41); The dynamic ring body (30) is sealed and inserted into the installation groove (41), and the dynamic ring body (30) can move along its own axis; A compression spring (42) is provided between the mounting end surface of the dynamic ring body (30) and the bottom of the mounting groove (41).

7. The dry gas sealing structure according to claim 6, characterized in that: The dynamic ring seat (40) is provided with a limiting block (44), and the limiting block (44) is located at the notch of the installation groove (41) to limit the dynamic ring body (30) within the installation groove (41).

8. The hybrid dry gas seal structure according to any one of claims 1 to 7, characterized in that: A damping portion (14) is provided in the air supply channel (11), and a damping hole communicating with the air supply channel (11) is provided in the damping portion (14).

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