A novel hydraulic dry gas seal stability structure

Abstract

The present invention discloses a novel dry gas seal structure, which includes a housing, a rotor, a dynamic ring assembly capable of rotating with the rotor, a static ring assembly matching with the dynamic ring assembly, and a static pusher assembly matching with the static ring assembly. The dynamic ring assembly includes a dynamic ring, the static ring assembly includes a static ring, and the static pusher assembly includes a hydraulic system located inside the housing. The hydraulic system includes an output shaft driven by hydraulic pressure, the movement direction of the output shaft is along the axis direction of the housing, and a foil is installed between the end face of the output shaft and the end face of the static ring. The present invention provides a novel dry gas seal structure to solve the problems existing in the dry gas seal technology in the prior art, such as non-adjustable end face spacing, low universality, uneven force, etc. in high-pressure, ultra-high-speed complex working conditions and large shaft diameter machinery applications, so as to achieve the purpose of making the gas film thickness controllable and adjustable, improving the sealing performance, expanding the universality of the dry gas seal structure, and at the same time applying the compensation force in the form of surface load to avoid uneven force.

Description

Technical Field

[0001] The present invention relates to the field of dry gas seals, and particularly to a novel hydraulic dry gas seal stability structure. Background Art

[0002] Dry gas seal is a non-contact mechanical seal technology. During the rotation of the spiral groove on the dynamic ring end face, the end face film pressure increases, making the formed opening force greater than the closing force acting on the sealing ring. A very thin gas film is formed between the friction pairs, which completely prevents the relatively low-pressure sealing medium from leaking out, thereby achieving "zero leakage" of the sealing medium.

[0003] With the improvement of the modern industrial development level, the application of traditional dry gas seal technology in high-pressure, ultra-high-speed complex working conditions and large shaft diameter machinery is restricted. The main reasons are as follows: First, under high-pressure working conditions, the spring of the traditional compensation ring will undergo plastic deformation, resulting in insufficient elastic force, insufficient stiffness of the dynamic and static ring seal end face films, and leakage of the sealing medium. Second, in ultra-high-speed dry gas seal devices, due to the excessively high rotation speed, the opening force keeps growing non-linearly, seriously affecting the change of the opening force of the seal end face. The gas film stiffness of the dynamic and static ring end faces cannot meet the required values, resulting in a large seal leakage. Third, after the seal end face has been used for a period of time, due to wear of the seal end face, the leakage will increase, and in the long run, it will damage the seal end face and even cause seal failure, resulting in the inability of the seal to operate stably for a long period. The above problems severely limit the further development of dry gas seal technology in high-pressure, ultra-high-speed complex working conditions and large shaft diameter machinery fields. To overcome the above problems, the applicant of this case previously applied for a magnetic coupling type dry gas seal structure (CN 112923063 B). This structure replaces the traditional spring compensation through magnetic coupling, achieving a breakthrough in dry gas seal technology in the field of large shaft diameter machinery. However, with the continuous in-depth research, this existing technology gradually exposes problems such as the non-adjustability of the distance between the dynamic and static ring end faces resulting in low versatility, and the magnetic repulsive force being equivalent to a point load resulting in uneven stress. Therefore, there is still a large room for improvement in the static ring followability in this existing technology. Summary of the Invention

[0004] The present invention provides a novel hydraulic dry gas seal stability structure to solve the problems existing in the application of dry gas seal technology in high-pressure, ultra-high-speed complex working conditions and large shaft diameter machinery in the prior art, such as non-adjustable end face distance, low versatility, and uneven stress, and to achieve the purpose of making the gas film thickness controllable and adjustable, improving the sealing performance, expanding the versatility of the dry gas seal structure, and applying the compensation force in the form of surface load to avoid uneven stress.

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

[0006] A novel hydraulic dry gas seal stability structure, comprising a housing, a rotor, a dynamic ring assembly capable of rotating with the rotor, a static ring assembly matching the dynamic ring assembly, and a static ring pushing assembly matching the static ring assembly. The dynamic ring assembly includes a dynamic ring, the static ring assembly includes a static ring, and the static ring pushing assembly includes a hydraulic system located inside the housing. The hydraulic system includes an output shaft driven by hydraulic pressure, and the movement direction of the output shaft is along the axis direction of the housing. A foil is installed between the end face of the output shaft and the end face of the static ring.

[0007] Aiming at the problems of non-adjustable end face spacing, low universality, uneven force, etc. existing in the dry gas seal technology in high-pressure, ultra-high-speed complex working conditions and large shaft diameter machinery applications in the prior art, the present invention proposes a novel hydraulic dry gas seal stability structure, in which the housing, rotor, dynamic ring, static ring, etc. are all prior arts, and the static ring pushing assembly is used to compensate the static ring. In the prior art, whether it is the traditional spring compensation method or the compensation method using magnetic coupling, there are defects in the non-adjustable gas film opening. If the gas film opening needs to be changed, springs with different stiffnesses or magnets with different magnetic field sizes need to be replaced, which obviously leads to poor applicability of the sealing device. Based on this, this application improves the static ring pushing assembly and uses a hydraulic system as the static ring pushing assembly. Its output shaft is driven by hydraulic pressure and can move linearly along the axis of the housing, so as to drive the static ring to move, thereby realizing the adjustment of the end face spacing between the dynamic ring and the static ring, that is, the gas film opening size can be flexibly adjusted, and the gas film opening size can be adjusted to a suitable position according to the actual application working conditions, so as to meet the requirement of controlling the gas film stiffness of the dry gas seal and achieve the final sealing effect.

[0008] In addition, in this application, the end face of the output shaft and the end face of the static ring are connected by a foil. First, the foil is used to realize the flexible installation between the output shaft and the static ring, avoiding direct rigid contact between the output shaft and the static ring, which can play a good buffering and force transmission effect, enabling the static ring to follow the dynamic ring to work within a certain inclination range, avoiding seal failure in the inclined state, and more importantly, avoiding the collision and damage of the static and dynamic rings (seal interface rubbing) that are prone to occur without buffering; secondly, through the foil setting, due to the sheet structure of the foil, the surface load can be applied to the static ring through the flexible force transmission of the foil, which can effectively overcome the problem of uneven force on the static ring caused by the static ring pushing assembly applying point load to the static ring in the prior art, significantly improving the stability and reliability of the static ring following, and ensuring the stable opening and closing of the sealing surface.

[0009] At the same time, this application adopts a hydraulic compensation method, which solves the problems of stress relaxation, creep deformation, etc. caused by uneven spring load on the static ring due to high temperature and corrosion in the traditional technology, and avoids the problems of seal interface rubbing and seal failure caused by spring stress relaxation and creep deformation.

[0010] In the specific application of this application, when the device is stationary, under the action of the hydraulic system, the moving ring and the stationary ring remain in a closed state. When the device starts, the end face membrane pressure of the dry gas seal increases. When the formed opening force is equal to the closing force acting on the sealing ring, a very thin gas film will be formed between the moving ring and the stationary ring. The formed gas film completely blocks the leakage channel of the relatively low-pressure sealing medium, achieving "zero leakage" of the sealing medium. During normal operation, under the action of the hydraulic system, the moving and stationary rings generate a rigid gas film pressure to block the outward leakage of the medium, thereby achieving the sealing effect and ensuring the stable operation of the dry gas seal. During the operation of this application, the gas film pressure of the sealing end face can be controlled according to the operating conditions, thereby significantly improving the operating level of the dry gas seal technology in high-pressure, ultra-high-speed complex working conditions, and large shaft diameter equipment. It has the advantages of stable long-term operation and extremely strong versatility.

[0011] Further, the hydraulic system includes an annular hydraulic cylinder and a partition located inside the annular hydraulic cylinder. The partition divides the interior of the annular hydraulic cylinder into a balanced hydraulic chamber and a thrust hydraulic chamber. An oil nozzle is provided on the balanced hydraulic chamber and / or the thrust hydraulic chamber;

[0012] The output shaft is annular and fixedly connected to the partition; the output shaft passes through the partition and extends out of the end of the balanced hydraulic chamber to the outside of the annular hydraulic cylinder and is connected to the foil.

[0013] In this solution, the oil nozzle is used to add hydraulic oil and connect to the hydraulic oil tank to adjust the relative pressure between the balanced hydraulic chamber and the thrust hydraulic chamber on both sides of the partition, thereby achieving the purpose of adjusting the end face spacing and the size of the gas film opening. The output shaft is a hollow shaft, which is convenient for being concentrically distributed with the annular hydraulic cylinder. It is fixedly connected to the partition, and the partition moves in the cylinder as a piston to drive the output shaft to move. Of course, any existing dynamic sealing technology is used to cooperate between the partition and the inner wall of the hydraulic cylinder to prevent the leakage of hydraulic oil. The output shaft passes through the partition and extends out of the end of the balanced hydraulic chamber to the outside of the annular hydraulic cylinder and is connected to the foil. Therefore, in this solution, the balanced hydraulic chamber is located at one end of the hydraulic cylinder close to the stationary ring, and the thrust hydraulic chamber is located at one end of the hydraulic cylinder far from the stationary ring. By changing the relative pressure difference between the balanced hydraulic chamber and the thrust hydraulic chamber through the hydraulic regulation system, the relative position of the output shaft is adjusted. The hydraulic system in this solution is a closed-loop system. During specific use, according to the operating requirements of the device, by calculating the opening pressure required for the dry gas seal, and then adjusting the balanced hydraulic valve and the thrust hydraulic valve to make the balanced hydraulic pressure and the thrust hydraulic pressure reach the required pressure requirements.

[0014] Further, the annular hydraulic cylinder includes a cover plate located at the end of the balanced hydraulic chamber; it also includes an elastic member located inside the annular hydraulic cylinder. The elastic member is connected between the inner wall of the annular hydraulic cylinder far from the cover plate and the output shaft.

[0015] The cover plate is used to seal the end of the hydraulic cylinder to maintain its sealed state. The output shaft necessarily needs to pass through the cover plate and be in dynamic seal cooperation with it.

[0016] The elastic member is located inside the annular hydraulic cylinder and is connected between the annular hydraulic cylinder and the output shaft. It is used to provide buffering for the movement of the output shaft and control the movement rate of the output shaft to be uniform and stable. The reason for its setting is that the gas film thickness of the dry gas seal is very thin (generally in the millimeter level), and the adjustment process should be very gentle. When adjusting the hydraulic pressure difference, it is easy to cause the action speed of the output shaft to be too fast and the moving distance to be too large due to various mistakes, which are not conducive to the precise regulation of the gas film gap. This solution overcomes the above problems by using an elastic member to improve buffering to ensure the uniform and stable movement rate of the output shaft. It should be noted that the elastic member of this application is completely different from the spring used in traditional dry gas seal technology, and their functions and purposes are completely different.

[0017] Furthermore, it also includes a ball bearing and a cylindrical bearing connected between the outer wall of the annular hydraulic cylinder and the output shaft. The ball bearing is located in the balance hydraulic chamber, and the cylindrical bearing is located in the thrust hydraulic chamber.

[0018] In this solution, both the ball bearing and the cylindrical bearing are used to cooperate between the output shaft and the inner wall of the hydraulic cylinder, for supporting the output shaft and cooperating with the left and right movement of the output shaft. Since both are located inside the hydraulic cylinder, automatic lubrication can be achieved by hydraulic oil, which can ensure a very long working life. Among them, the ball bearing is located in the balance hydraulic chamber, that is, the ball bearing is installed at the end relatively closer to the stationary ring, and its function is to balance and support the output shaft for linear motion; the cylindrical bearing is located in the thrust hydraulic chamber, that is, the cylindrical bearing is installed at the end relatively farther from the stationary ring, and its function is to cooperate with the elastic member to enable the output shaft to continuously output linearly.

[0019] In this solution, the positions of the ball bearing and the cylindrical bearing cannot be interchanged, otherwise it will seriously interfere with the working effect.

[0020] Furthermore, the output shaft includes a first small-diameter section, a large-diameter section, and a second small-diameter section distributed in sequence. The outer diameter of the large-diameter section is greater than the outer diameters of the first small-diameter section and the second small-diameter section. The ball bearing is located outside the first small-diameter section, the partition is located outside the large-diameter section, and the cylindrical bearing is located outside the second small-diameter section.

[0021] In this solution, the output shaft includes three sections along the axial direction. The first small-diameter section and the second small-diameter section are respectively located on both axial sides of the large-diameter section, providing installation positions for the ball bearing and the cylindrical bearing respectively. The outer diameter of the large-diameter section is relatively larger and is used to install and connect the partition. In addition, due to the difference in the outer diameters between the three sections on the output shaft, a stepped surface is inevitably formed between the large-diameter section and the first small-diameter section and the second small-diameter section on both sides. This stepped surface can also increase the bearing area and assist the partition to achieve a more stable driving effect on the output shaft.

[0022] Further, a number of V-shaped grooves are symmetrically distributed on both side surfaces of the foil. In this solution, a number of V-shaped grooves are opened on both side surfaces of the foil, and the V-shaped grooves on both sides are opposite to each other one by one, making the foil more flexible, having a better flexible connection effect between the output shaft and the stationary ring, and further reducing the risk of rubbing at the sealing interface.

[0023] Further, the moving ring assembly includes a moving ring seat sleeved outside the rotor, and the moving ring is installed in the moving ring seat; it also includes a compression sleeve for fixing the moving ring in the moving ring seat and a fastening ring fixedly connected to the rotor; the fastening ring is fixedly connected to the compression sleeve, and the compression sleeve is fixedly connected to the moving ring seat. Since the fastening ring is fixedly connected to the rotor, in this solution, the moving ring seat, the moving ring, the compression sleeve and the fastening ring can all rotate synchronously with the rotor to achieve the function of the moving ring. At the same time, this solution can prevent the moving ring from having axial displacement.

[0024] Further, the fastening ring and the compression sleeve are fixedly connected by bolts, and the compression sleeve and the moving ring seat are fixedly connected by a snap ring to improve the integrity of the moving ring assembly.

[0025] Further, a labyrinth seal is provided between the housing and the rotor. The labyrinth seal is a prior art and will not be elaborated here.

[0026] Further, the stationary ring assembly includes a stationary ring seat, and the stationary ring is located in the stationary ring seat; the stationary ring seat and the housing are fixedly connected by a snap ring, and the snap ring is located at one end of the stationary ring seat along the axial direction away from the direction where the moving ring assembly is located. The snap ring is used to provide axial limit for the stationary ring seat to ensure the relative static state of the stationary ring seat.

[0027] Further, a balance hydraulic chamber nozzle is provided on the balance hydraulic chamber, and a thrust hydraulic chamber nozzle is provided on the thrust hydraulic chamber; it also includes two groups of hydraulic oil tanks for respectively providing hydraulic oil for the balance hydraulic chamber nozzle and the thrust hydraulic chamber nozzle, a pressure automatic controller for controlling the pressures of the two groups of hydraulic oil tanks, and instrument air for providing air source for the pressure automatic controller.

[0028] In this solution, instrument air is provided as the driving gas source, and the pressure of two groups of hydraulic oil tanks is controlled by a pressure automatic controller, thereby controlling the inflow and outflow of hydraulic oil for two groups of oil nozzles, and realizing stable volume regulation of the balance hydraulic cavity and the thrust hydraulic cavity. Those skilled in the art should understand that the pressure automatic controller can be realized by using an existing pressure controller; in addition, control valves can be adaptively arranged at positions such as between the hydraulic oil tank and the corresponding oil nozzle, and the outlet end of the instrument air.

[0029] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0030] 1. A novel hydraulic dry gas seal stability structure of the present invention solves the problems of seal interface rubbing and seal failure caused by stress relaxation, creep deformation, etc. due to uneven spring load on the stationary ring caused by high temperature and corrosion in the prior art through the setting of the hydraulic system, improves the operation reliability of the dry gas seal technology in high-pressure, ultra-high-speed complex working conditions, and large shaft diameter equipment, and has very important significance for the breakthrough application of the dry gas seal technology in the fields of high-pressure, ultra-high-speed and large shaft diameter machinery.

[0031] 2. A novel hydraulic dry gas seal stability structure of the present invention can drive the stationary ring to move through the hydraulic system, thereby realizing the adjustment of the distance between the dynamic ring and the stationary ring end face, that is, the opening degree of the gas film can be flexibly adjusted, and the opening degree of the gas film can be adjusted to a suitable position according to the actual application working condition requirements, so as to meet the requirement of controlling the gas film stiffness of the dry gas seal, and significantly improve the versatility in the field of large shaft diameter machinery.

[0032] 3. A novel hydraulic dry gas seal stability structure of the present invention uses a foil to achieve flexible installation between the output shaft and the stationary ring, avoiding direct rigid contact between the output shaft and the stationary ring, which can achieve a good buffer force transmission effect, enabling the stationary ring to work following the dynamic ring within a certain inclination range, avoiding seal failure in the inclined state, and reducing the risk of seal interface rubbing that is likely to occur without a buffer effect.

[0033] 4. A novel hydraulic dry gas seal stability structure of the present invention can apply a surface load to the stationary ring through flexible force transmission of the foil, effectively overcoming the problem of uneven force on the stationary ring caused by applying a point load to the stationary ring by the push-stationary component in the prior art, significantly improving the stability and reliability of the stationary ring following, and further improving the stable opening and closing ability of the seal surface; and because the force provided by the hydraulic pressure to the output shaft is stable and continuous, it can continuously apply a radially inward thrust to the stationary ring as a whole, ensuring that the stationary ring can move followingly and ensuring continuous, stable and smooth operation between the dynamic and stationary rings.

[0034] 5. A novel hydraulic dry gas seal stability structure of the present invention adopts a hydraulic compensation method, which solves the problems of stress relaxation, creep deformation, etc. caused by uneven spring loads on the stationary ring due to high temperature and corrosion in the traditional technology, and avoids problems such as seal interface rubbing and seal failure caused by spring stress relaxation and creep deformation.

[0035] 6. A novel hydraulic dry gas seal stability structure of the present invention improves buffering through elastic components to ensure uniform and stable movement speed of the output shaft, and avoids problems such as low accuracy in regulating the airtight gap caused by too fast movement speed and too large movement distance of the output shaft.

[0036] 7. A novel hydraulic dry gas seal stability structure of the present invention balances through a ball bearing and supports the output shaft for linear motion; through a cylindrical bearing cooperating with an elastic component, the output shaft can continuously output linearly, significantly improving the stability and reliability of the operation of the dry gas seal device under high pressure and high interface sliding speed. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] The drawings described herein are used to provide a further understanding of the embodiments of the present invention, form a part of this application, and do not limit the embodiments of the present invention. In the drawings:

[0038] Figure 1 is an axial sectional view of a specific embodiment of the present invention;

[0039] Figure 2 is a structural schematic diagram of the stationary ring assembly in a specific embodiment of the present invention;

[0040] Figure 3 is a structural schematic diagram of the hydraulic system in a specific embodiment of the present invention;

[0041] Figure 4 is a structural schematic diagram of the output shaft in a specific embodiment of the present invention;

[0042] Figure 5 is a cross-sectional view of the foil in a specific embodiment of the present invention;

[0043] Figure 6 is a structural schematic diagram of the moving ring assembly in a specific embodiment of the present invention;

[0044] Figure 7 is a schematic diagram of the hydraulic regulation and control system in a specific embodiment of the present invention.

[0045] Marks in the drawings and corresponding component names:

[0046] 1 - Rotor, 2 - Labyrinth seal, 3 - Sealing ring, 4 - Rotating ring, 5 - Housing, 6 - Stationary ring, 7 - Foil, 8 - Nozzle, 9 - Baffle, 10 - Snap ring, 11 - Bolt I, 12 - Bolt II, 13 - Snap ring II, 14 - Elastic member, 15 - Annular hydraulic cylinder, 16 - Compression sleeve, 17 - Rotating ring seat, 18 - Hydrodynamic groove, 19 - Snap ring III, 20 - Fastening ring, 21 - Bolt hole, 22 - Cylindrical bearing, 23 - Output shaft, 231 - First small diameter section, 232 - Large diameter section, 233 - Second small diameter section, 24 - Ball bearing, 25 - Cover plate, 26 - Balance hydraulic chamber, 27 - Thrust hydraulic chamber, 107 - Instrument air control valve, 108 - Thrust hydraulic control valve, 109 - Balance hydraulic control valve. Detailed implementation mode

[0047] To make the objectives, technical solutions and advantages of the present invention clearer and more understandable, the present invention will be further described in detail below in conjunction with embodiments and drawings. The illustrative implementation modes and descriptions of the present invention are only used to explain the present invention and are not intended to limit the present invention. In the description of the present application, it should be understood that the orientation or positional relationships indicated by the terms "front", "rear", "left", "right", "up", "down", "vertical", "horizontal", "high", "low", "inner", "outer", etc. are based on the orientation or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as limiting the protection scope of the present application.

[0048] Embodiment 1:

[0049] As Figures 1 to 3 shown, a novel hydraulic dry gas seal stability structure includes a housing 5, a rotor 1, a rotating ring assembly that can rotate with the rotor 1, a stationary ring assembly that matches the rotating ring assembly, and a stationary pushing assembly that matches the stationary ring assembly. The rotating ring assembly includes a rotating ring 4, the stationary ring assembly includes a stationary ring 6, and the stationary pushing assembly includes a hydraulic system located in the housing 5. The hydraulic system includes an output shaft 23 driven by hydraulic pressure, and the movement direction of the output shaft 23 is along the axis direction of the housing 5. A foil 7 is installed between the end face of the output shaft 23 and the end face of the stationary ring 6.

[0050] The hydraulic system in this embodiment includes an annular hydraulic cylinder 15 and a baffle 9 located in the annular hydraulic cylinder 15. The baffle 9 divides the interior of the annular hydraulic cylinder 15 into a balance hydraulic chamber 26 and a thrust hydraulic chamber 27. Nozzles 8 are provided on the balance hydraulic chamber 26 and the thrust hydraulic chamber 27. The output shaft 23 is annular and fixedly connected to the baffle 9. The output shaft 23 passes through the baffle 9 and extends out of the end of the balance hydraulic chamber 26 to the outside of the annular hydraulic cylinder 15 and is connected to the foil 7.

[0051] The annular hydraulic cylinder 15 includes a cover plate 25 located at the end of the balanced hydraulic chamber 26; it also includes an elastic member 14 located inside the annular hydraulic cylinder 15, and the elastic member 14 is connected between the inner wall of the annular hydraulic cylinder 15 away from the cover plate 25 and the output shaft 23.

[0052] In this embodiment, the elastic member 14 is a spring, which is located inside the annular hydraulic cylinder, with one end connected to the inner wall of the annular hydraulic cylinder and the other end connected to the output shaft. The output shaft 23 is a hollow shaft, which can reduce the load on the one hand and meet the installation requirements on the other hand.

[0053] It also includes a ball bearing 24 and a cylindrical bearing 22 connected between the outer wall of the annular hydraulic cylinder 15 and the output shaft 23. The ball bearing 24 is located in the balanced hydraulic chamber 26, and the cylindrical bearing 22 is located in the thrust hydraulic chamber 27.

[0054] In this embodiment, the stationary ring 6 is flexibly installed with the hydraulic system shaft through the foil 7, and the hydraulic system can make the output shaft move left and right along the axial direction through the action of the hydraulic regulation and control system, so as to adjust the size of the gas film opening to a suitable position, thereby meeting the requirement of controlling the stiffness of the sealing gas film.

[0055] In the prior art, each spring / magnet is annularly distributed on the back of the push stationary ring, and then the spring force / magnetic force is transmitted to the stationary ring by the push stationary ring. Since the acting force exerted by each spring on the push stationary ring can be regarded as a point load, the problem of uneven force on the stationary ring exists. In this embodiment, through the setting of the foil, the flexible force transmission by the foil and the surface load can effectively overcome the problem of uneven force on the stationary ring in the prior art, and further ensure the stable and reliable followability of the stationary ring, and ensure the stable opening and closing of the sealing surface.

[0056] As Figure 7 shown, this embodiment also includes two groups of hydraulic oil tanks for supplying hydraulic oil to the balanced hydraulic chamber nozzle and the thrust hydraulic chamber nozzle respectively, a pressure automatic controller for controlling the pressure of the two groups of hydraulic oil tanks, and instrument air for supplying air source to the pressure automatic controller.

[0057] During the operation of this embodiment, hydraulic oil is injected into the balance hydraulic chamber and the thrust hydraulic chamber through the nozzle 8. At the same time, the nozzle is also used to connect with the hydraulic oil tank in the hydraulic regulation and control system. By calculating the seal opening pressure, the balance hydraulic control valve 109 and the thrust hydraulic control valve 108 are adjusted to achieve the required pressure requirements for the balance hydraulic pressure and the thrust hydraulic pressure, enabling the output shaft 23 to flexibly transmit the force to the static ring 6 through the foil 7. Under normal conditions, the dynamic and static rings are normally closed. When operating, due to the pressure generated by the gas pumped by the dynamic ring 4, the dynamic and static rings open, and the static ring 6 pushes the output shaft 23 to move to the right through the foil 7. Through the combined action of the balance hydraulic pressure, the thrust hydraulic pressure, the ball bearing 24, the cylindrical bearing 22, and the spring, the output shaft 23 can move flexibly left and right, pushing the static ring assembly to adjust the thickness of the end face gas film, achieving the required gas film pressure requirements between the end faces of the dynamic and static rings, and further controlling the stiffness of the end face gas film to achieve the best sealing performance.

[0058] In this embodiment, hydraulic oil compensation is used, which also has the advantages of high pressure resistance, high temperature resistance, good lubricity, cleanliness, etc.

[0059] In this embodiment, the instrument air control valve 107 is used to control the size of the instrument air, and the instrument air is used for the adjustment of the pressure automatic controller. The pressure controller can be directly installed and used with existing technologies and will not be elaborated here.

[0060] This embodiment is mainly designed for the sealing short board of large shaft diameter rotating equipment, and can also improve the sealing performance under complex operating conditions and complex environments.

[0061] In a more preferred embodiment, O-rings are used for the sealing of the entire hydraulic system and the auxiliary sealing at other positions.

[0062] It should be noted that Figure 2 the foil 7 in the figure is blocked by the static ring 6 and cannot be shown.

[0063] Embodiment 2:

[0064] A novel hydraulic dry gas seal stability structure, on the basis of Embodiment 1, as Figures 1 to 6 shown, the output shaft 23 includes a first small diameter section 231, a large diameter section 232, and a second small diameter section 233 that are distributed in sequence. The outer diameter of the large diameter section 232 is greater than the outer diameters of the first small diameter section 231 and the second small diameter section 233; the ball bearing 24 is located outside the first small diameter section 231, the partition 9 is located outside the large diameter section 232, and the cylindrical bearing 22 is located outside the second small diameter section 233.

[0065] The moving ring assembly includes a moving ring seat 17 sleeved outside the rotor 1, and the moving ring 4 is installed inside the moving ring seat 17; it further includes a pressing sleeve 16 for fixing the moving ring 4 inside the moving ring seat 17, and a fastening ring 20 fixedly connected to the rotor 1; the fastening ring is fixedly connected to the pressing sleeve 16, and the pressing sleeve 16 is fixedly connected to the moving ring seat 17. The fastening ring and the pressing sleeve 16 are fixedly connected by bolts 21, and the pressing sleeve 16 and the moving ring seat 17 are fixedly connected by snap ring III 19.

[0066] The stationary ring assembly includes a stationary ring seat, and the stationary ring 6 and the hydraulic system are both located inside the stationary ring seat; the stationary ring seat is fixedly connected to the housing 5 by snap ring I 10, and the snap ring I 10 is located at one end of the stationary ring seat along the axial direction away from the direction where the moving ring assembly is located.

[0067] In a more preferred embodiment, a number of V-shaped grooves are symmetrically distributed on both side surfaces of the foil 7.

[0068] In a more preferred embodiment, a labyrinth seal 2 is provided between the housing 5 and the rotor 1. As is well known to those skilled in the art, the labyrinth seal 2 includes comb teeth at the end of the housing, and there is a small gap between the comb teeth and the rotor.

[0069] In a more preferred embodiment, both the moving ring and the stationary ring are made of silicon carbide.

[0070] In a more preferred embodiment, the elastic member 14 is a spring, which is installed inside a spring seat, and the spring seat is fixedly installed inside the hydraulic cylinder.

[0071] The specific embodiments described above further elaborate on the purpose, technical solutions, and beneficial effects of the present invention. It should be understood that the above are only specific embodiments of the present invention and are not used to limit the protection scope of the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included within the protection scope of the present invention.

[0072] It should be noted that in this article, relational terms such as first and second, I, II, and III are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the term "comprising", "including", or any other variant thereof is intended to cover non-exclusive inclusion, so that a process, method, article, or device including a series of elements not only includes those elements but also includes other elements not explicitly listed, or further includes elements inherent to such process, method, article, or device. In addition, the term "connected" used in this article, without special explanation, can be directly connected or indirectly connected via other components.

Claims

1. A novel hydraulic dry gas seal stability structure, comprising a housing (5), a rotor (1), a dynamic ring assembly capable of rotating with the rotor (1), a static ring assembly matching with the dynamic ring assembly, and a static ring pushing assembly matching with the static ring assembly. The dynamic ring assembly includes a dynamic ring (4), and the static ring assembly includes a static ring (6), characterized in that, The static pushing assembly includes a hydraulic system located inside the housing (5). The hydraulic system includes an output shaft (23) driven by hydraulic pressure. The moving direction of the output shaft (23) is along the axis direction of the housing (5). A foil (7) is installed between the end face of the output shaft (23) and the end face of the static ring (6). The hydraulic system includes an annular hydraulic cylinder (15) and a partition (9) located inside the annular hydraulic cylinder (15). The partition (9) divides the inside of the annular hydraulic cylinder (15) into a balance hydraulic cavity (26) and a thrust hydraulic cavity (27). An oil nozzle (8) is provided on the balance hydraulic cavity (26) and / or the thrust hydraulic cavity (27). The output shaft (23) is annular and fixedly connected to the partition (9). The output shaft (23) passes through the partition (9) and passes out of the end of the balance hydraulic cavity (26) to the outside of the annular hydraulic cylinder (15) and is connected to the foil (7). The annular hydraulic cylinder (15) includes a cover plate (25) located at the end of the balance hydraulic cavity (26). It also includes an elastic member (14) located inside the annular hydraulic cylinder (15). The elastic member (14) is connected between the inner wall of the annular hydraulic cylinder (15) far from the cover plate (25) and the output shaft (23). It also includes a ball bearing (24) and a cylindrical bearing (22) connected between the outer wall of the annular hydraulic cylinder (15) and the output shaft (23). The ball bearing (24) is located inside the balance hydraulic cavity (26), and the cylindrical bearing (22) is located inside the thrust hydraulic cavity (27).

2. The novel hydraulic dry gas seal stability structure according to claim 1, characterized in that, The output shaft (23) includes a first small-diameter section (231), a large-diameter section (232), and a second small-diameter section (233) distributed in sequence. The outer diameter of the large-diameter section (232) is greater than the outer diameters of the first small-diameter section (231) and the second small-diameter section (233). The ball bearing (24) is located outside the first small-diameter section (231), the partition (9) is located outside the large-diameter section (232), and the cylindrical bearing (22) is located outside the second small-diameter section (233).

3. The novel hydraulic dry gas seal stability structure according to claim 1, characterized in that, A number of V-shaped grooves are symmetrically distributed on both side surfaces of the foil (7).

4. The novel hydraulic dry gas seal stability structure according to claim 1, characterized in that, The moving ring assembly includes a moving ring seat (17) sleeved outside the rotor (1). The moving ring (4) is installed inside the moving ring seat (17). It also includes a compression sleeve (16) for fixing the moving ring (4) inside the moving ring seat (17) and a fastening ring (20) fixedly connected to the rotor (1). The fastening ring is fixedly connected to the compression sleeve (16), and the compression sleeve (16) is fixedly connected to the moving ring seat (17).

5. The novel hydraulic dry gas seal stability structure according to claim 4, characterized in that, The fastening ring and the pressing sleeve (16) are fixedly connected by bolts (21), and the pressing sleeve (16) and the moving ring seat (17) are fixedly connected by a snap ring (19).

6. The novel hydraulic dry gas seal stability structure according to claim 1, characterized in that, The static ring assembly includes a static ring seat. The static ring (6) is located inside the static ring seat. The static ring seat is fixedly connected to the housing (5) through a snap ring I (10). The snap ring I (10) is located at one end of the static ring seat along the axial direction away from the direction where the moving ring assembly is located.

7. The novel hydraulic dry gas seal stability structure according to claim 1, characterized in that, A balance hydraulic oil nozzle is provided on the balance hydraulic cavity (26), and a thrust hydraulic oil nozzle is provided on the thrust hydraulic cavity (27); it further includes two groups of hydraulic oil tanks for supplying hydraulic oil to the balance hydraulic oil nozzle and the thrust hydraulic oil nozzle respectively, a pressure automatic controller for controlling the pressure of the two groups of hydraulic oil tanks, and instrument air for supplying air source to the pressure automatic controller.

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