Multifunctional derivative V-shaped groove type dry gas sealing device and using method

Abstract

The invention discloses a multifunctional derivative V-shaped groove type dry gas sealing device and a using method, and relates to the technical field of mechanical sealing. Comprising a sealing assembly, and a static ring and a moving ring which are assembled in the sealing assembly. Wherein the inner diameter of the movable ring is larger than 58 mm, the outer diameter of the movable ring is smaller than 78 mm, a plurality of sets of V-shaped grooves are evenly formed in the surface of the movable ring, triangular structures are arranged in the V-shaped grooves, the surfaces of the triangular structures and the surface of the movable ring are located on the same plane, the triangular structures and the V-shaped grooves are combined to form derivative V-shaped grooves with two air inlet channels, the width of the derivative V-shaped grooves ranges from 2 mm to 6 mm, and the ends of the derivative V-shaped grooves are arc-shaped parts. The circumferential center of the arc-shaped part coincides with the circle center of the movable ring, and the included angle of the V-shaped groove ranges from 55 degrees to 65 degrees. The V-shaped groove is designed, the dynamic pressure groove of an angular structure is additionally formed in the end of the V-shaped groove, the pressure of medium gas in the dynamic pressure groove is concentrated, the pressure is increased, the pressure is more evenly distributed in the groove, the opening force of a gas film can be effectively improved, and the stability of the gas film is guaranteed.

Description

Technical Field

[0001] The invention relates to the technical field of mechanical seals, and in particular to a multifunctional derivative V-groove dry gas seal device and a use method thereof. Background Art

[0002] In the fields of machinery, chemical industry, energy and power, traditional sealing technologies such as labyrinth seals, mechanical seals and floating ring seals have long been the mainstream choice in the industry. However, with the advancement of technology and the continuous improvement of production efficiency requirements, these traditional sealing methods have gradually exposed some shortcomings, which are usually manifested in high energy consumption, low reliability, complicated operation procedures, relatively short service life and high operation and maintenance costs. These problems have prompted the industry to seek more advanced and efficient sealing solutions.

[0003] Dry gas seal, as an innovative non-contact mechanical sealing method, came into being under this background. It uses dry and clean gas as the sealing medium, which significantly reduces friction and wear, and greatly reduces the risk of leakage. Because it uses pollution-free sealing medium, dry gas seal not only improves environmental friendliness, but also is widely used in various equipment that requires long-term stable operation due to its highly reliable performance. In addition, this sealing method can reduce maintenance requirements while ensuring long-term and efficient operation of equipment, becoming an important technological advancement in the field of modern fluid machinery.

[0004] However, although unidirectional rotary dry gas seals perform well in many application scenarios, they still have limitations when facing certain specific working conditions. For example, when it comes to reverse rotation caused by the structure of rotating equipment or the manufacturing process, this type of seal may not be able to provide sufficient fluid dynamic pressure to maintain normal operation, thereby affecting the opening force and causing increased wear on the seal end face. Once this happens, the sealing performance will be greatly reduced, increasing the risk of leakage. Therefore, in order to overcome this challenge, it is particularly important to develop a dry gas seal that can adapt to bidirectional rotation and produce a better dynamic pressure effect. This not only ensures that there will be no end face wear during the startup phase of the equipment, but also enables long-term stable operation of the equipment.

[0005] In-depth research has found that the shape and geometric parameters of the microgrooves on the dynamic ring of the dry gas seal are crucial to improving the sealing performance. By optimizing the design of these microgrooves, the dynamic pressure effect of the sealing device can be effectively improved, thereby enhancing its opening performance, ensuring that the equipment can maintain excellent sealing effect and long service life even under complex working conditions. Therefore, future research and development directions should focus on how to accurately design and manufacture these key components to further promote the development of dry gas sealing technology. Summary of the invention

[0006] Purpose of the invention: Based on the problems mentioned in the background technology, a multifunctional derivative V-groove dry gas sealing device and a method of use are proposed.

[0007] Technical solution: A multifunctional derivative V-groove dry gas sealing device, comprising a sealing assembly, and a static ring and a dynamic ring assembled in the sealing assembly; the inner diameter of the dynamic ring is greater than 58 mm, and the outer diameter is less than 78 mm;

[0008] A plurality of groups of V-shaped grooves are evenly provided on the surface of the dynamic ring; a triangular structure is provided in the V-shaped groove; the surface of the triangular structure is in the same plane as the surface of the dynamic ring, and is combined with the V-shaped groove to form a derived V-shaped groove having two air inlet channels; the width of the derived V-shaped groove is 2 to 6 mm;

[0009] The end of the derived V-shaped groove is an arc-shaped portion, and the circumferential center of the arc-shaped portion coincides with the center of the moving ring; the included angle of the V-shaped groove is 55 to 65 degrees.

[0010] In a further embodiment, the arc-shaped portion of the derived V-shaped groove extends to both sides along its length direction to form a first dynamic pressure groove.

[0011] In a further embodiment, the first dynamic pressure groove has its symmetry axis and opens a second dynamic pressure groove toward the center of the dynamic ring.

[0012] In a further embodiment, both side edges of the second dynamic pressure groove converge toward the diameter of the dynamic ring along the center of the dynamic ring outward.

[0013] In a further embodiment, two ends of the first dynamic pressure groove are angular, respectively serving as level I dynamic pressure grooves; the angle of the level I dynamic pressure groove is 25 to 30°.

[0014] In a further embodiment, the notch of the second dynamic pressure groove extends to both sides along the circumferential direction of the dynamic ring to form a third dynamic pressure groove with two level II dynamic pressure groove ends; the angle of the level II dynamic pressure groove is 25 to 30°.

[0015] In a further embodiment, the groove-to-weir ratio of the dynamic ring is 1.4 to 1.5, and the groove-to-dam ratio is 0.7 to 0.9.

[0016] In a further embodiment, the depth of the V-groove is 1 to 9 μm; the number of grooves ranges from 6 to 14; the derived V-groove is a symmetrical structure, and is symmetrical along the center of the moving ring and along the diameter of the moving ring.

[0017] In a further embodiment, the sealing assembly includes: a rotating shaft, a spring seat, a spring, a sealing O-ring, a sleeve, comb teeth, and a push ring, wherein the sealing O-ring is installed in the sleeve for assembling the dynamic ring; the sleeve is fixedly installed on the rotating shaft; the static ring is installed between the push ring and the spring seat, the static ring is in contact with the surface of the dynamic ring, a spring is installed between the push ring and the spring seat, and the comb teeth are fixedly connected to the rotating shaft.

[0018] A method for using a multifunctional derivative V-groove dry gas seal is implemented based on any of the multifunctional derivative V-groove dry gas seal devices described above, comprising the following steps:

[0019] S1, driving the moving ring to rotate, and the medium gas enters the derived V-shaped groove on the end surface of the moving ring;

[0020] S2. Affected by the sealing weir, the airflow slows down and increases in pressure, and continues to move toward the inner end of the derived V-shaped groove;

[0021] S3, the airflow generates a new pressure peak at the end of the inner side of the derived V-shaped groove;

[0022] S4, forming an air film on the end surface of the moving ring;

[0023] S5. When the opening force is greater than the closing force, the air film formed will push the static ring open, the spring will be compressed, and the gap between the dynamic ring and the static ring will increase;

[0024] When the opening force is less than the closing force, the spring stretches and the gap between the dynamic ring and the static ring decreases;

[0025] When the opening force is equal to the closing force, the dry gas seal operates stably.

[0026] Beneficial effects:

[0027] 1. The derived V-groove structure designed in the present invention has a symmetrical structural feature, which can meet the requirements of bidirectional rotation and avoid the limitation of unidirectional rotation.

[0028] 2. The V-shaped opening groove makes it easier to pump the sealing medium gas into the groove when the dynamic ring rotates. After the airflow enters the V-shaped inlet, it flows to the root of the groove. Affected by the V-shaped inlet sealing weir, the airflow slows down and increases the pressure; after the airflow reaches the root of the groove, it is affected by the rotation speed and forms a high-pressure area on one side of the groove; at the same time, the pressure of the airflow in the dynamic pressure groove added at the bottom of the groove root is further increased due to the sharp corner pressurization. The setting of the two-stage dynamic pressure groove makes the distribution area of ​​the high-pressure area in the groove larger and more uniform. It can ensure a strong dynamic pressure effect, increase the opening force of the air film, and the air film formed between the dynamic and static rings has greater rigidity and better stability. It can effectively reduce end face wear, achieve long-term stable operation of dry gas sealing equipment, extend service life, and reduce equipment failures due to insufficient opening force.

[0029] 3. Compared with a single V-shaped groove structure, by adding an angular dynamic pressure groove at the end of the V-shaped groove, the pressure of the medium gas is concentrated in the dynamic pressure groove, which increases the pressure and distributes the pressure more evenly in the groove, which can effectively improve the opening force of the air film and ensure the stability of the air film. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 It is a schematic structural diagram of the dry gas sealing device of the present invention.

[0031] Figure 2 It is a schematic diagram of the V-groove dynamic ring structure of the present invention.

[0032] Figure 3 It is a schematic diagram of the dynamic ring structure in Example 2 of the present invention.

[0033] Figure 4 It is a schematic diagram of the dynamic ring structure in Example 3 of the present invention.

[0034] Figure 5 It is a schematic diagram of the dynamic ring structure in Example 4 of the present invention.

[0035] Figure 6 It is a schematic diagram of the structure of the static ring and the dynamic ring in Example 5 of the present invention.

[0036] Figure 7 It is a schematic diagram of the derived V-groove end face structure in Example 5 of the present invention.

[0037] Figure 8 It is a schematic diagram of the partial structure of the derived V-groove end face structure in Example 5 of the present invention.

[0038] The markings in the figure are: dynamic ring 1, sealing O-ring 2, sleeve 3, comb teeth 4, rotating shaft 5, spring seat 6, spring 7, static ring 8, fixing pin 9, locking sleeve 10, push ring 11, sealing weir 12, sealing dam 13, level I dynamic pressure groove 14, level II dynamic pressure groove 15, triangular structure 16, first dynamic pressure groove 17, second dynamic pressure groove 18, derived V-shaped groove 19. DETAILED DESCRIPTION

[0039] The present invention will be further described below in conjunction with the accompanying drawings.

[0040] Example 1

[0041] Based on the problems in the background technology, the present application proposes a multifunctional derivative V-groove dry gas sealing device, which mainly includes a sealing assembly, and a dry gas sealing structure such as a static ring 8 and a dynamic ring 1 assembled in the sealing assembly. The sealing assembly of the present application is as follows Figure 1As shown, it includes a rotating shaft 5, a spring 7 seat 6, a spring 7, a sealing O-ring 2, a sleeve 3, comb teeth 4, a fixing pin 9, a locking sleeve 10, a push ring 11, a dynamic ring 1, and a static ring 8. The specific installation method is that a sealing O-ring 2 made of fluororubber is installed in the ring groove of the sleeve 3, and then the dynamic ring 1 is installed in the sleeve 3 by interference fit, the dynamic ring 1 is circumferentially positioned by the fixing pin 9, the sleeve 3 is fixed on the rotating shaft 5, and the locking sleeve 10 is axially positioned on the dynamic ring 1 to ensure that the dynamic ring 1 rotates with the rotating shaft 5. The static ring 8 is fixed between the push ring 11 and the spring 7 seat 6 by interference fit, and the matching surface is coated with molybdenum disulfide solid lubricant. The spring 7 is installed between the push ring 11 and the spring 7 seat 6. The comb teeth 4 are installed to form a clearance fit with the rotating shaft 5 to ensure that the tip of the comb teeth 4 forms a taper fit of 0.5 to 1° with the sleeve 3 axially.

[0042] The design of this embodiment lies in the design of the surface groove of the dynamic ring 1, such as Figures 2 to 8 As shown, the inner diameter of the moving ring 1 is greater than 58 mm, and the outer diameter is less than 78 mm. A plurality of groups of V-grooves are evenly arranged on the surface of the moving ring 1. The V-grooves in this embodiment are, as the name implies, approximately V-shaped structures. A triangular barrier structure is arranged in the V-groove. The upper surface of the triangular structure 16 is in the same plane as the surface of the moving ring 1, and is combined with the V-groove to form a derived V-groove with two air inlet channels. The width of the derived V-groove is 2 to 6 mm, and the end of the derived V-groove is arranged as an arc structure, i.e., an arc portion. The circumferential center of the arc portion coincides with the center of the moving ring 1. The angles of all V-grooves in this embodiment are 55 to 65°.

[0043] The dynamic ring 1 also includes a sealing weir 12 and a sealing dam 13 .

[0044] The opening force refers to the resultant fluid pressure generated by the dynamic pressure effect of the air film between the sealing end faces. Its direction is opposite to the closing force (the sealing surface compression force generated by spring force, medium pressure, etc.). It is a core mechanical parameter used to balance the closing force and maintain the non-contact operating state.

[0045] In this embodiment, the depth of the V-shaped groove is 1 to 9 μm, and the number of grooves ranges from 6 to 14. The derived V-shaped groove is a symmetrical structure, and is symmetrical along the center of the moving ring 1 and along the diameter of the moving ring 1 .

[0046] In this embodiment, the stationary ring 8 can be made of carbon graphite material, and the material of the dynamic ring 1 can be SiC.

[0047] The specific working content of this embodiment is: when the high-pressure sealing medium gas is injected into the dry gas sealing device from above, the dynamic ring 1 and the static ring 8 remain closed under the action of the spring 7 and the medium pressure, and the sealing device is in a static pressure sealing state.

[0048] When the device is started, the rotating shaft 5 drives the dynamic ring 1 to rotate. The above-mentioned derivative V-shaped groove structure on the surface of the dynamic ring 1 will pump the medium gas into the sealing end surface of the dynamic ring 1. The medium gas generates a dynamic pressure effect in the groove, generating an opening force. The opening force will push open the static ring 8. Figure 1 As shown, the push ring 11 is moved to the left, the spring 7 is compressed, and the force of the spring 7 increases.

[0049] After stable operation, the sum of the spring 7 force and the medium sealing force is equal to the opening force. At this time, an air film with a thickness of 2 to 5 μm will be formed on the sealing end surface of the dynamic and static ring 8, which has a good non-contact sealing effect.

[0050] Example 2

[0051] Based on Example 1, this example corresponds to Figure 3 ,for Figure 2 The derivative scheme is a derivative V-shaped groove of a single ring end face structure, and its arc portion extends to both sides along its length direction to form an arc-shaped strip groove as the first dynamic pressure groove 17. The two ends of the first dynamic pressure groove 17 can be polygonal structures, such as rectangular ends. The first dynamic pressure groove 17 is usually an annular dynamic pressure groove structure.

[0052] The specific design scheme is that the radius r of the first dynamic pressure groove 17 is g3 = 67.48mm, the ratio of the circumferential slot length of the annular groove to the weir area is 1.6, the ratio of the radial slot width to the weir area is 0.5, and the rest is as shown in the attached Figure 2 structure.

[0053] Example 3

[0054] On the basis of Example 2, Figure 4 As shown, it is a derivative scheme of Example 2, the first dynamic pressure groove 17 has its symmetry axis and opens the second dynamic pressure groove 18 toward the center of the dynamic ring 1, and the two side edges of the second dynamic pressure groove 18 converge toward the diameter of the dynamic ring 1 along the center of the dynamic ring 1 outward.

[0055] Based on Example 2, a dovetail-shaped dynamic pressure groove is added at the end of the annular dynamic pressure groove structure, and the radius of the dovetail-shaped dynamic pressure groove is r g4 =64.48mm, the ratio of the circumferential groove length of the dovetail groove to the length of the annular dynamic pressure groove is 0.4, the ratio of the radial groove width to the width of the annular dynamic pressure groove is 1, the angle at the dovetail is 50°, and the other structural parameters are consistent with the structure in Implementation 2.

[0056] Example 4

[0057] On the basis of Examples 1 to 3, Figure 5As shown, in this embodiment, both ends of the first dynamic pressure groove 17 are optimized, changing the polygonal structure into an angular structure, serving as the first-level dynamic pressure groove 14, with an angle of 25 to 30 degrees.

[0058] That is, a straight groove structure along the radial direction is designed at the groove root of the second-level dynamic pressure groove 15, and the straight groove radius r g5 =64.48mm, the ratio of the circumferential slot length of the straight slot to the first-level dynamic pressure groove 14 is 0.3, the ratio of the radial slot width to the first-level dynamic pressure groove 14 is 1, and the other structural parameters are the same as the derived V-groove.

[0059] Example 5

[0060] On the basis of Examples 1 to 3, Figure 6 As shown, this embodiment further optimizes the design of the second dynamic pressure groove 18. The notch of the second dynamic pressure groove 18 extends to both sides along the circumferential direction of the dynamic ring 1 to form a third dynamic pressure groove. The third dynamic pressure groove has two level II dynamic pressure grooves 15. The angle of the level II dynamic pressure groove 15 is 25 to 30°.

[0061] In order to better illustrate this solution, Example 5 is described in detail. Figures 6 to 8 As shown, the outer diameter of the moving ring 1 is r o =77.78mm, inner diameter of moving ring 1 r i =58.42mm, the V-shaped groove structure as described above is processed by laser on the surface of the dynamic ring 1, which is evenly distributed along the circumferential direction, with 12 grooves. Its structure mainly includes a derived V-shaped groove entrance composed of two inclined grooves with an angle of 60° and connected at the bottom, and a first-level dynamic pressure groove 14 and a second-level dynamic pressure groove 15 added at the groove root. Among them, the entrance groove width is 6mm, and the radius of the first-level dynamic pressure groove 14 is r g1 =66.88mm, radius r of level II dynamic pressure groove 15 g2 =63mm, the groove-dam ratio is 1.45, the groove-dam ratio is 0.8, the two ends of the two dynamic pressure grooves are pointed, the tangential angle is 28°, and the groove depth is 6μm.

[0062] Its working mode is that when the dynamic ring 1 rotates with the rotating shaft 5, the medium gas is pumped into the derived V-shaped groove on the end face of the dynamic ring 1 under the action of speed and pressure. The derived V-shaped groove inlet with a certain inclination angle makes it easier for the airflow to enter the groove. After the airflow enters the groove, it is affected by the sealing weir, the airflow is decelerated and pressurized, and continues to move to the groove root.

[0063] Affected by the rotation speed, the airflow will form a high-pressure area on one side of the derived V-groove. The airflow in the I-level dynamic pressure groove 14 and the II-level dynamic pressure groove 15 is pressurized by the sharp corners to generate a new pressure peak. At the same time, under the influence of the two dynamic pressure grooves, the pressure distribution of the airflow in the groove is more uniform, resulting in a strong dynamic pressure effect, forming a layer of air film on the end face of the dynamic ring 1, which plays a sealing role. The opening force of the air film increases. When the opening force is greater than the closing force, the formed air film will push the static ring 8 open, the spring 7 is compressed, and the gap between the dynamic ring 1 and the static ring 8 increases; when the opening force is less than the closing force, the spring 7 stretches, and the gap between the dynamic ring 1 and the static ring 8 decreases; when the opening force is equal to the closing force, the dry gas sealing device operates stably.

[0064] That is, a number of evenly distributed derivative V-groove structures are arranged along the circumferential direction on the end face of the dynamic ring 1. The outer side of the end face of the dynamic ring 1 is a high-pressure sealing medium area, and the inner side is a low-pressure area. The surface of the dynamic ring 1 is provided with a derivative V-groove structure. The derivative V-groove is a symmetrical structure and can realize bidirectional rotation, that is, the inlet is composed of two inclined grooves with an angle of 60°. The inclined grooves with a certain inclination angle make it easier for the medium gas to enter the groove, and produce a better dynamic pressure effect in the groove. At the same time, the two inclined grooves are equivalent to two air intake channels. Affected by the rotation speed, one channel is the main air intake. The incoming airflow flows to another channel under the action of centrifugal force. The other channel is affected by the medium pressure and the pumping of the airflow. The incoming airflow will block the airflow from the previous channel in the channel, thereby forming a high-pressure area in the channel. In this embodiment, the two ends of the dynamic pressure groove are pointed, and the airflow is pressurized. The setting of the two-stage dynamic pressure groove makes the pressure evenly distributed in the groove, which can produce a strong dynamic pressure effect and a large opening force.

[0065] The derived V-groove in Example 5 was compared with the V-groove mentioned in Example 1 through simulation experiments under different working conditions. Except for the different groove structures, the other parameters were consistent.

[0066] Working condition 1: pressure 1 to 8MPa, speed 10000rpm, film thickness 2μm, the comparison results are as follows:

[0067] Table 1 Opening force changes with pressure

[0068]

[0069] Working condition 2: pressure 4.58MPa, speed 6000 to 20000rpm, film thickness 2μm, the comparison results are as follows:

[0070] Table 2 Opening force changes with pressure and speed

[0071]

[0072]

[0073] The comparison results show that under different working conditions, the derived V-groove in Example 5 has a higher opening force and better opening performance than the V-groove in Example 1.

[0074] The above are only preferred embodiments of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. Multifunctional derivative V-groove dry gas sealing device, characterized in that: It comprises a sealing assembly, and a static ring and a dynamic ring assembled in the sealing assembly; the inner diameter of the dynamic ring is greater than 58 mm, and the outer diameter is less than 78 mm; A plurality of groups of V-shaped grooves are evenly provided on the surface of the dynamic ring; a triangular structure is provided in the V-shaped groove; the surface of the triangular structure is in the same plane as the surface of the dynamic ring, and is combined with the V-shaped groove to form a derived V-shaped groove having two air inlet channels; the width of the derived V-shaped groove is 2 to 6 mm; The end of the derived V-shaped groove is an arc-shaped portion, and the circumferential center of the arc-shaped portion coincides with the center of the moving ring; the included angle of the V-shaped groove is 55 to 65 degrees.

2. The multifunctional derivative V-groove dry gas sealing device according to claim 1, characterized in that: The arc-shaped portion of the derived V-shaped groove extends to both sides along its length direction to form a first dynamic pressure groove.

3. The multifunctional derivative V-groove dry gas sealing device according to claim 2, characterized in that: The first dynamic pressure groove has a symmetry axis and a second dynamic pressure groove is formed toward the center of the dynamic ring.

4. The multifunctional derivative V-groove dry gas sealing device according to claim 3, characterized in that: Both side edges of the second dynamic pressure groove converge toward the diameter of the dynamic ring along the center of the dynamic ring toward the outside.

5. The multifunctional derivative V-groove dry gas sealing device according to claim 3, characterized in that: The two ends of the first dynamic pressure groove are angular, respectively serving as the first-level dynamic pressure grooves; the angle of the first-level dynamic pressure groove is 25 to 30 degrees.

6. The multifunctional derivative V-groove dry gas sealing device according to claim 5, characterized in that: The notch of the second dynamic pressure groove extends to both sides along the circumferential direction of the dynamic ring to form a third dynamic pressure groove with two level II dynamic pressure groove ends; the angle of the level II dynamic pressure groove is 25 to 30 degrees.

7. The multifunctional derivative V-groove dry gas sealing device according to claim 6, characterized in that: The groove-to-weir ratio of the moving ring is 1.4 to 1.5, and the groove-to-dam ratio is 0.7 to 0.

9.

8. The multifunctional derivative V-groove dry gas sealing device according to claim 1, characterized in that: The depth of the V-shaped groove is 1 to 9 μm; the number of grooves ranges from 6 to 14; the derived V-shaped groove is a symmetrical structure, and is symmetrical along the center of the moving ring and along the diameter of the moving ring.

9. The multifunctional derivative V-groove dry gas sealing device according to claim 1, characterized in that: The sealing assembly includes: a rotating shaft, a spring seat, a spring, a sealing O-ring, a sleeve, comb teeth, and a push ring, wherein the sealing O-ring is installed in the sleeve for assembling the dynamic ring; the sleeve is fixedly installed on the rotating shaft; the static ring is installed between the push ring and the spring seat, the static ring is in contact with the surface of the dynamic ring, a spring is installed between the push ring and the spring seat, and the comb teeth are fixedly connected to the rotating shaft.

10. A method for using a multifunctional derivative V-groove dry gas seal, based on the multifunctional derivative V-groove dry gas seal device according to any one of claims 1 to 9, characterized in that: The following steps are involved: S1, driving the moving ring to rotate, and the medium gas enters the derived V-shaped groove on the end surface of the moving ring; S2. Affected by the sealing weir, the airflow slows down and increases in pressure, and continues to move toward the inner end of the derived V-shaped groove; S3, the airflow generates a new pressure peak at the end of the inner side of the derived V-shaped groove; S4, forming an air film on the end surface of the moving ring; S5. When the opening force is greater than the closing force, the air film formed will push the static ring open, the spring will be compressed, and the gap between the dynamic ring and the static ring will increase; When the opening force is less than the closing force, the spring stretches and the gap between the dynamic ring and the static ring decreases; When the opening force is equal to the closing force, the dry gas seal operates stably.

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