Mechanical sealing structure of turbine pump

Abstract

The invention discloses a mechanical sealing structure of a turbine pump, and belongs to the technical field of turbine pumps. Comprising a shell, a ring body mechanism and an elastic compensation assembly. The spoilers of the auxiliary supporting piece are evenly distributed in the circumferential direction, all-directional radial wrapping type supporting is formed for the elastic piece, the radial deviation and high-frequency vibration of the elastic piece caused by centrifugal force during high-speed operation of the turbopump can be effectively resisted, collision interference between the elastic piece and a peripheral structure can be avoided, and the service life of the turbopump is prolonged. And it is ensured that axial pressing force output by the elastic piece is evenly distributed in the circumferential direction of the movable ring, and the problem of local leakage or excessive abrasion of the sealing end face caused by uneven pressure of a traditional structure is thoroughly solved.

Description

Technical Field

[0001] This application relates to the field of turbopump technology, and more specifically, to a turbopump mechanical seal structure. Background Technology

[0002] In high-end equipment fields such as aerospace, energy and power, and petrochemicals, turbopumps are core components for fluid transport and pressurization, and their operational reliability directly determines the stability and safety of the entire equipment system. Mechanical seals, as the core component of the turbopump shaft end seal, primarily function to apply axial pressure to the rotating ring through elastic elements, ensuring a tight seal between the rotating and stationary rings. This prevents leakage of high-pressure fluid within the pump chamber, reduces wear on the sealing face, and guarantees long-term stable operation of the turbopump under harsh conditions such as high speed, high pressure, and strong corrosion.

[0003] In existing mechanical seal structures for turbopumps, the elastic element generally uses a single helical spring or disc spring as the elastic support component, which provides axial clamping force to the moving ring through the pre-compression of the spring. However, in practical applications, this type of traditional elastic support structure has many insurmountable defects: First, the radial support stability of the spring is poor. Under the centrifugal force generated by the high-speed operation of the turbine pump, the spring is prone to radial displacement or vibration, resulting in uneven axial pressure distribution on the rotating ring. This leads to uneven gaps on the sealing end face between the rotating and stationary rings. In some areas, insufficient pressure can create leakage channels, or excessive pressure can exacerbate end face wear, seriously affecting the reliability and service life of the seal. Second, traditional sealing structures lack a dedicated axial displacement guiding mechanism. The rotating ring is prone to tilting during axial compensation, further deteriorating the sealing end face fit accuracy. Especially under conditions where there is slight axial movement or swaying of the pump shaft, the risk of seal failure increases significantly. Third, existing seals mostly use a single rectangular sealing ring, which has a limited sealing contact area. Moreover, the sealing performance is not enhanced by the linkage of elastic elements. Under the impact of high-pressure fluid, the sealing ring is prone to deformation or displacement, leading to seal failure.

[0004] To address the aforementioned issues, some improvement solutions attempted to improve pressure distribution by increasing the number of springs or optimizing the spring installation position. However, these solutions failed to fundamentally solve the problems of spring radial offset and insufficient guidance of the dynamic ring, and thus could not meet the stringent requirements of high-end turbopumps for sealing reliability, long service life, and resistance to harsh operating conditions.

[0005] Therefore, developing a technology that can achieve uniform pressure application, stable axial guidance, and enhanced sealing performance has become a technical challenge that urgently needs to be solved by those skilled in the art.

[0006] In view of this, a mechanical seal structure for a turbopump is proposed. Summary of the Invention

[0007] The purpose of this invention is to provide a mechanical seal structure for a turbopump to solve the problems mentioned in the background art.

[0008] This invention provides the following technical solution: a mechanical seal structure for a turbopump, comprising: A housing, comprising a sleeve and an end cap that is sealed to one end of the sleeve; The ring mechanism, located within the housing, includes a rotating ring and a stationary ring fitted onto the pump shaft, as well as a seal. The rotating ring is sealed and fixed to the pump shaft by the sealing element and is clearance-fitted with the sleeve. The stationary ring is sealed and fixed to the end cap by the sealing element; An elastic compensation assembly, disposed between the moving ring and the sleeve, includes: A telescopic cylinder, sleeved on the pump shaft and having an inner cylinder and an outer cylinder that can move axially relative to each other, is used to provide axial displacement guidance for the moving ring; An elastic element, sleeved on the outside of the telescopic cylinder, is used to provide axial clamping force to the moving ring; An auxiliary support member is disposed between the telescopic cylinder and the elastic member for radial support of the elastic member; A sealing reinforcement is disposed at one end of the telescopic cylinder and is connected to the auxiliary support in a driving manner, for axially pressing the sealing member to enhance the seal.

[0009] According to the above technical solution, a sealing pressure ring is provided between the mating surfaces of the sleeve and the end cap, and the cross-section of the sealing pressure ring is cross-shaped.

[0010] According to the above technical solution, a pressure bearing is installed at one end of the sleeve facing the telescopic cylinder, and a first sealing ring is pressed between the pressure bearing and the sleeve. The first sealing ring has an L-shaped cross section and is sleeved on the pump shaft.

[0011] According to the above technical solution, a plurality of through holes and grooves are provided on the end face of the first sealing ring that contacts the telescopic cylinder.

[0012] According to the above technical solution, the sealing end faces of the moving ring and the stationary ring are respectively an outwardly convex stepped surface and an inwardly concave stepped surface. Both the outwardly convex stepped surface and the inwardly concave stepped surface include an inner sealing area and an outer flow guiding area. The edge of the flow guiding area is chamfered.

[0013] According to the above technical solution, the sealing element includes: The second sealing ring, which is trumpet-shaped, is embedded in the inner wall of the moving ring and is sealed to the pump shaft and the sealing reinforcement respectively; The third sealing ring, which is wavy, is fitted onto the outer wall of the stationary ring and seals with the end cap.

[0014] According to the above technical solution, the flared end of the second sealing ring is provided with a sealed cavity, and the sealed cavity is filled with lubricant.

[0015] According to the above technical solution, the elastic element includes a helical spring coil and collars respectively sleeved on both ends of the spring coil, and the end face of the collar that contacts the telescopic cylinder is provided with a rubber layer.

[0016] According to the above technical solution, the auxiliary support includes a plurality of circumferentially distributed baffles, one end of which is rotatably connected to the outer cylinder of the telescopic cylinder, and the other end is slidably connected to the collar through a sliding column.

[0017] According to the above technical solution, the sealing reinforcement includes an extrusion ring, a rack frame, and a transmission gear; The compression ring abuts against the flared end of the second sealing ring; The rack frame comprises multiple rack frames, which are uniformly fixed to the side wall of the extrusion ring along the circumference and slide in cooperation with the outer cylinder of the telescopic cylinder; The transmission gear is fixed to the end of the rotating shaft of the spoiler and meshes with the rack frame.

[0018] Compared with the prior art, the beneficial effects of the present invention, using the above technical solution, are as follows: 1. This application utilizes multiple baffles evenly distributed circumferentially in the auxiliary support component to form a comprehensive radial wrapping support for the elastic component. This not only effectively resists the radial displacement and high-frequency vibration of the elastic component caused by centrifugal force during the high-speed operation of the turbine pump, but also avoids collision interference between the elastic component and the surrounding structure. It ensures that the axial clamping force output by the elastic component is evenly distributed circumferentially along the moving ring, completely solving the problem of local leakage or excessive wear of the sealing end face caused by uneven pressure in traditional structures. Furthermore, when the elastic component extends and retracts, driving the auxiliary support component to move, the transmission structure can drive the sealing reinforcement component to squeeze the sealing component, making the seal and the mating surface fit more tightly, significantly improving the sealing performance, effectively resisting the impact of high-pressure fluid, and further improving the sealing performance.

[0019] 2. The telescopic cylinder of this application forms a high-precision guide channel with the inner and outer cylinders that can move relative to each other axially, providing rigid constraints for the axial compensation movement of the rotating ring. Even under harsh working conditions where there is a slight axial movement or sway of the pump shaft, the tilt angle of the rotating ring can be strictly limited, ensuring that the fitting accuracy of the sealing end face of the rotating ring and the stationary ring is always in the optimal range, significantly reducing the risk of seal failure, while reducing the end face wear rate, and greatly extending the service life and maintenance cycle of the sealing structure.

[0020] 3. This application uses the meshing transmission of the transmission gear and the rack frame to drive the compression ring of the sealing reinforcement to axially compress the flared end of the second sealing ring. Under the compression action, the flared structure will expand to both sides, further increasing the tightness of contact with the pump shaft and the inner wall of the rotating ring, and improving the sealing effect. At the same time, the lubricant in the sealed cavity at the flared end of the second sealing ring can penetrate through the tiny gaps in the sealing surface to the sealing end faces of the rotating and stationary rings during the rotation of the rotating ring with the pump shaft, forming a continuous lubricating film and reducing relative rotational friction. Attached Figure Description

[0021] Figure 1 This is a cross-sectional view of the overall structure of the present invention; Figure 2 This is a schematic diagram of the shell structure of the present invention; Figure 3 This is a schematic diagram of the ring mechanism structure of the present invention; Figure 4 This is a schematic diagram of the elastic compensation component structure of the present invention; Figure 5 This is a schematic diagram of the telescopic cylinder structure of the present invention; Figure 6 This is a schematic diagram showing the disassembled structure of the elastic element of the present invention; Figure 7 This is a schematic diagram of some structural connections of the present invention.

[0022] Explanation of the numbers in the diagram: 100, housing; 110, sleeve; 111, pressure bearing; 112, first sealing ring; 120, end cap; 130, sealing pressure ring; 200, ring mechanism; 210, moving ring; 220, stationary ring; 230, sealing element; 231, second sealing ring; 232, third sealing ring; 240, sealing area; 250, flow guiding area; 300, elastic compensation component; 310, telescopic cylinder; 320, elastic element; 321, helical spring ring; 322, collar; 330, auxiliary support component; 331, spoiler; 332, sliding column; 340, sealing reinforcement component; 341, compression ring; 342, rack frame; 343, transmission gear. Detailed Implementation

[0023] The specific embodiments of the present invention will be further described below with reference to the accompanying drawings. It should be noted that these descriptions are for the purpose of aiding understanding the present invention, but do not constitute a limitation thereof. Furthermore, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0024] Reference Figures 1 to 7 A mechanical seal structure for a turbopump, comprising: The housing 100 includes a sleeve 110 and an end cap 120 that is sealed to one end of the sleeve 110; The ring mechanism 200 is located inside the housing 100 and includes a dynamic ring 210 and a stationary ring 220 sleeved on the pump shaft, as well as a seal 230. Among them, the dynamic ring 210 is sealed and fixed to the pump shaft by the sealing element 230, and is clearance-fitted with the sleeve 110; The stationary ring 220 is sealed and fixed to the end cap 120 by the sealing element 230; An elastic compensation component 300, disposed between the rotating ring 210 and the sleeve 110, includes: The telescopic cylinder 310 is sleeved on the pump shaft and has an inner cylinder and an outer cylinder that can move axially relative to each other, and is used to provide axial displacement guidance for the dynamic ring 210; The elastic element 320 is sleeved on the outside of the telescopic cylinder 310 and is used to provide axial clamping force to the rotating ring 210. An auxiliary support 330 is disposed between the telescopic cylinder 310 and the elastic member 320, and is used to radially support the elastic member 320. The sealing reinforcement 340 is located at one end of the telescopic cylinder 310 and is connected to the auxiliary support 330 for axial compression of the sealing member 230 to enhance the seal.

[0025] The mechanical seal structure of this turbopump consists of a stationary ring 220 sealed and fixed to the end cover 120 of the housing 100 via a seal 230, and a rotating ring 210 sealed and fixed to the pump shaft via a seal 230, maintaining a clearance fit with the sleeve 110 to ensure that the rotating ring 210 can rotate synchronously with the pump shaft without interfering with the sleeve 110. An elastic compensation component 300 is assembled between the rotating ring 210 and the sleeve 110, wherein a telescopic cylinder 310 is sleeved on the pump shaft, and its axially movable inner and outer cylinders provide axial compensation for the subsequent rotating ring 210. The guide base is provided, and the elastic element 320 is sleeved on the outside of the telescopic cylinder 310. In the initial state, a preset axial clamping force is applied to the moving ring 210, so that the sealing end face of the moving ring 210 and the stationary ring 220 is initially attached. The auxiliary support 330 is located between the telescopic cylinder 310 and the elastic element 320, forming a radial limiting support for the elastic element 320. The sealing reinforcement 340 is connected to the auxiliary support 330 in a transmission manner, and its compression ring 341 abuts against the second sealing ring 231 in the sealing element 230 to complete the assembly of the overall sealing structure. When the turbo pump starts, the pump shaft drives the rotating ring 210 to rotate synchronously, while the stationary ring 220 remains fixed. The elastic element 320 continuously applies axial clamping force to the rotating ring 210, ensuring that the sealing end faces of the rotating ring 210 and the stationary ring 220 are always tightly fitted, blocking the leakage of high-pressure fluid in the pump chamber. During high-speed operation, the multiple baffles 331 of the auxiliary support 330 effectively limit the radial displacement of the elastic element 320 through the rotational connection with the outer cylinder of the telescopic cylinder 310 and the sliding connection with the collar 322, avoiding vibration of the elastic element 320 due to centrifugal force, and ensuring the uniform distribution of its axial pressure on the rotating ring 210. As operating time increases, wear occurs on the sealing end faces of the rotating ring 210 and the stationary ring 220. At this time, the elastic element 320 elastically expands and contracts, pushing the rotating ring 210 to move axially along the inner and outer cylinder guide directions of the telescopic cylinder 310, realizing automatic compensation for wear and ensuring continuous contact of the sealing end faces. At the same time, the expansion and contraction of the elastic element 320 drives the collar 322 to move, which drives the baffle 331 to rotate around the outer cylinder of the telescopic cylinder 310 through the sliding column 332. The transmission gear 343 at the end of the rotating shaft of the baffle 331 meshes with the rack frame 342, driving the compression ring 341 to axially compress the second sealing ring 231, making the second sealing ring 231 more tightly fitted with the pump shaft and the inner wall of the rotating ring 210, realizing the linkage enhancement of sealing performance and further improving the sealing reliability under high pressure conditions.

[0026] Reference Figure 1 and Figure 2 A sealing ring 130 is provided between the mating surfaces of the sleeve 110 and the end cover 120. The cross-section of the sealing ring 130 is cross-shaped. A pressure bearing 111 is installed at one end of the sleeve 110 facing the telescopic cylinder 310. A first sealing ring 112 is pressed between the pressure bearing 111 and the sleeve 110. The cross-section of the first sealing ring 112 is L-shaped and is sleeved on the pump shaft. Multiple through holes and grooves are opened on the end face of the first sealing ring 112 that contacts the telescopic cylinder 310.

[0027] The mechanical seal structure of this turbopump features a cross-shaped sealing ring 130 at the mating surface of the sleeve 110 and the end cover 120. When the sleeve 110 and the end cover 120 are fixed by fasteners, the cross-shaped structure of the sealing ring 130 can form a sealing contact in both the axial and radial directions, filling the tiny gaps at the mating surface and blocking the channel for high-pressure fluid leakage from the mating surface. Compared with traditional flat sealing rings, the cross-shaped structure has stronger resistance to deformation and can prevent the sealing of the mating surface from failing due to the vibration of the turbopump during operation. A pressure bearing 111 is installed at the end of the sleeve 110 facing the telescopic cylinder 310. The pressure bearing 111 can withstand the thrust generated by the axial movement of the telescopic cylinder 310, reducing the direct friction between the sleeve 110 and the telescopic cylinder 310. An L-shaped first sealing ring 112 is pressed between the pressure bearing 111 and the sleeve 110, and the first sealing ring 112 is sleeved on the pump shaft. One end of its L-shaped structure is attached to the inner wall of the sleeve 110, and the other end is attached to the surface of the pump shaft, forming a bidirectional sealing protection to prevent fluid leakage from the gap between the pressure bearing 111 and the sleeve 110 and the pump shaft. At the same time, multiple through holes and grooves are opened on the end face of the first sealing ring 112 that contacts the telescopic cylinder 310. When the telescopic cylinder 310 moves axially, the holes and grooves can guide the lubricating medium in the housing 100 to circulate. On the one hand, it provides lubrication for the contact surface between the first sealing ring 112 and the telescopic cylinder 310, reducing relative motion wear. On the other hand, it can carry away the heat generated during operation with the lubricating medium to achieve heat dissipation and cooling.

[0028] Reference Figure 1 and Figure 3 The sealing end faces of the moving ring 210 and the stationary ring 220 are respectively a convex stepped surface and a concave stepped surface. Both the convex stepped surface and the concave stepped surface include an inner sealing area 240 and an outer guiding area 250. The edge of the guiding area 250 is chamfered.

[0029] The mechanical seal structure of this turbopump, through the sealing end faces of the dynamic ring 210 and the stationary ring 220, is the core defense line to block high-pressure fluid leakage. Its matching design of the convex and concave stepped surfaces, combined with the functional division of the sealing area 240 and the flow guiding area 250, achieves the synergistic effect of sealing and flow guiding. When the rotating ring 210 rotates synchronously with the pump shaft, under the axial clamping force of the elastic element 320, its convex stepped surface precisely fits the concave stepped surface of the stationary ring 220. Compared with the traditional planar structure, the stepped structure can increase the sealing contact area and form multiple sealing barriers, extending the leakage path of high-pressure fluid and improving the basic sealing capacity. Moreover, the guiding effect of the stepped surface can further ensure the coaxiality of the rotating ring 210 and the stationary ring 220, and avoid misalignment of the sealing end face caused by the sway caused by high-speed operation. When the high-pressure fluid in the pump chamber penetrates into the sealing end face, it first contacts the guide zone 250 on the outer side of the stepped surface of the rotating ring 210 and the stationary ring 220. The chamfered design of the edge of the guide zone 250 can guide the fluid to flow smoothly along the surface of the guide zone, avoiding the fluid directly impacting the inner sealing zone 240. At the same time, the pressure difference effect formed by the stepped structure can reduce the pressure impact of the fluid on the sealing zone 240, reduce the wear of the sealing end face, and ensure the sealing stability of the sealing zone 240. During the fluid flow, the guide zone 250 can also guide some of the lubricating medium to the edge of the sealing zone 240, providing auxiliary lubrication for the sealing end face and reducing relative rotational friction.

[0030] Reference Figure 1 and Figure 3 The seal 230 includes: The second sealing ring 231 is trumpet-shaped and is embedded in the inner wall of the moving ring 210. It is sealed and engaged with the pump shaft and the sealing reinforcement 340 respectively. The trumpet end of the second sealing ring 231 is provided with a sealed cavity, which is filled with lubricant. The third sealing ring 232 is wavy and is fitted onto the outer wall of the stationary ring 220, and is sealed to the end cap 120.

[0031] The mechanical seal structure of this turbopump uses the seal 230 as the key sealing component between the dynamic ring and the pump shaft, and between the stationary ring and the end cover. The differentiated structural design of the second sealing ring 231 and the third sealing ring 232 is adapted to the needs of different sealing scenarios. At the same time, the sealing reinforcement 340 is used to achieve dynamic enhancement of sealing performance. The second sealing ring 231 is horn-shaped and embedded in the inner wall of the rotating ring 210. Its two ends are respectively sealed and engaged with the pump shaft and the sealing reinforcement 340, forming a sealing barrier between the rotating ring 210 and the pump shaft. When the turbo pump is running, when the elastic element 320 extends and retracts, it drives the auxiliary support 330 to move. Through the meshing of the transmission gear 343 and the rack frame 342, the compression ring 341 of the sealing reinforcement 340 is driven to axially compress the horn-shaped end of the second sealing ring 231. Under the compression, the horn-shaped structure expands to both sides, further increasing the tightness of contact with the pump shaft and the inner wall of the rotating ring 210, and improving the sealing effect. At the same time, the sealed cavity at the horn-shaped end of the second sealing ring 231 is filled with lubricant. During the rotation of the rotating ring 210 with the pump shaft, the lubricant can penetrate through the tiny gaps in the sealing surface to the sealing end face of the rotating ring 210 and the stationary ring 220, forming a continuous lubricating film and reducing relative rotational friction. The third sealing ring 232 is wavy and fitted onto the outer wall of the stationary ring 220, and is sealed to the end cover 120. Vibrations generated during the operation of the turbine pump or minor deviations during assembly may cause a slight relative displacement between the stationary ring 220 and the end cover 120. The wavy structure can adaptively compensate for this displacement through the elastic deformation of its own crests and troughs, always maintaining a tight fit with the outer wall of the stationary ring 220 and the inner wall of the end cover 120, thus preventing fluid leakage from the gap between the stationary ring 220 and the end cover 120. At the same time, the wavy structure increases the sealing contact area and improves the resistance to high-pressure fluids.

[0032] Reference Figure 4 and Figure 6 The elastic element 320 includes a helical spring coil 321 and collars 322 respectively sleeved on both ends of the spring coil 321. The end face of the collar 322 that contacts the telescopic cylinder 310 is provided with a rubber layer.

[0033] The mechanical seal structure of this turbine pump consists of an elastic element 320 composed of a helical spring ring 321 and a collar 322. The helical spring ring 321 adopts a double-layer structure with an inner spring ring and an outer spring ring connected together. It is fitted outside the telescopic cylinder 310. During initial assembly, a preset axial elastic force is generated by pre-compression. This elastic force is evenly transmitted to the moving ring 210 through the collars 322 at both ends, so that the sealing end face of the moving ring 210 and the stationary ring 220 forms a stable contact pressure. Compared with the traditional single helical spring, the double-layer nested helical spring ring 321 can effectively disperse the force, avoid local elastic force concentration, and ensure the uniform distribution of axial clamping force. The collars 322 are respectively fitted onto both ends of the helical spring coil 321, and the end face that contacts the telescopic cylinder 310 is provided with a rubber layer. When the moving ring 210 needs axial compensation due to wear, the moving ring 210 drives the collars 322 to move axially along the telescopic cylinder 310. At this time, the rubber layer on the end face of the collars 322 can reduce the sliding friction resistance between the collars and the telescopic cylinder 310 and avoid wear caused by hard contact. At the same time, the collars 322 limit both ends of the helical spring coil 321 to prevent radial displacement of the helical spring coil 321 during the extension and retraction process. Together with the auxiliary support 330, the radial stability of the elastic element 320 is further improved.

[0034] Reference Figure 4 and Figure 7 The auxiliary support 330 includes a plurality of circumferentially distributed spoilers 331. One end of the spoiler 331 is rotatably connected to the outer cylinder of the telescopic cylinder 310, and the other end is slidably connected to the collar 322 through the sliding column 332.

[0035] The mechanical seal structure of this turbopump, through the core function of the auxiliary support component 330, is to provide stable radial support for the elastic component 320, and at the same time, it works with the collar 322 to achieve motion linkage, ensuring the accuracy of elastic compensation; Among them, the auxiliary support 330 is composed of multiple circumferentially evenly distributed baffles 331, which are assembled between the telescopic cylinder 310 and the elastic member 320. When the turbo pump is running at high speed, the elastic member 320 is prone to radial displacement due to centrifugal force. At this time, the circumferentially evenly distributed baffles 331 can form an all-round radial limit on the outer periphery of the elastic member 320, effectively blocking the radial displacement of the elastic member 320, avoiding collision or vibration with the surrounding structure, and ensuring the stable output of the axial clamping force of the elastic member 320. Furthermore, one end of the spoiler 331 is rotatably connected to the outer cylinder of the telescopic cylinder 310, and the other end is slidably connected to the collar 322 via the sliding column 332. When the moving ring 210 requires axial compensation due to wear, the elastic element 320 extends and retracts, causing the collar 322 to move axially along the telescopic cylinder 310. The movement of the collar 322 is transmitted to the spoiler 331 through the sliding column 332, driving the spoiler 331 to rotate around the connection point of the outer cylinder of the telescopic cylinder 310. During this process, the spoiler 331 always maintains a close and supportive state with the elastic element 320, and achieves adaptive angle adjustment with the movement of the collar 322. This does not affect the extension and retraction compensation of the elastic element 320, and continuously provides radial support for it. At the same time, the centrifugally rotating spoiler 331 can not only generate a turbulent effect on the lubricating medium in the housing 100, promote the circulation of the lubricating medium, and improve the heat dissipation effect, but also squeeze the lubricating medium when it is centrifuged, causing the spoiler 331 to expand the telescopic cylinder 310, further improving the sealing performance of the ring mechanism 200.

[0036] Reference Figure 4 and Figure 7 The sealing reinforcement 340 includes a compression ring 341, a rack frame 342, and a transmission gear 343; The compression ring 341 abuts against the flared end of the second sealing ring 231; Multiple rack frames 342 are uniformly fixed to the side wall of the extrusion ring 341 along the circumference and slide in cooperation with the outer cylinder of the telescopic cylinder 310. The transmission gear 343 is fixed to the end of the rotating shaft of the spoiler 331 and meshes with the rack frame 342.

[0037] The mechanical seal structure of this turbopump uses the sealing reinforcement 340 as the core component to achieve the linkage enhancement of elastic support and sealing performance. Through the transmission cooperation of the extrusion ring 341, rack frame 342 and transmission gear 343, the movement of the auxiliary support 330 is converted into the extrusion force of the sealing component 230. The sealing reinforcement 340 is assembled at one end of the telescopic cylinder 310. The extrusion ring 341 directly abuts against the flared end of the second sealing ring 231 in the sealing component 230. Multiple rack frames 342 are uniformly fixed to the side wall of the extrusion ring 341 in the circumferential direction and form a sliding fit with the outer cylinder of the telescopic cylinder 310 to ensure that the extrusion ring 341 can move stably along the axial direction of the telescopic cylinder 310. The transmission gear 343 is fixed to the end of the rotating shaft of the spoiler 331 in the auxiliary support component 330 and precisely meshes with the rack frame 342 to form a complete linkage link of "spoiler rotation - gear transmission - rack movement - extrusion ring extrusion". When wear occurs in the rotating ring 210 during the operation of the turbopump, the elastic element 320 extends and retracts, causing the collar 322 to move axially. This drives the baffle 331 to rotate around the outer cylinder of the telescopic cylinder 310 via the sliding column 332. When the baffle 331 rotates, the transmission gear 343 at the end of its shaft rotates synchronously. Through meshing with the rack frame 342, the circular motion is converted into the axial linear motion of the rack frame 342. Since the rack frame 342 is fixedly connected to the compression ring 341, it drives the compression ring 341 to move axially along the sliding direction of the outer cylinder of the telescopic cylinder 310, generating a precise compression force on the flared end of the second sealing ring 231. Under the compression action, the flared second sealing ring 231 expands to both sides, further increasing the tightness of the sealing contact with the pump shaft and the inner wall of the rotating ring 210, thereby achieving dynamic enhancement of sealing performance. When the turbo pump is under high pressure, the high pressure fluid in the pump chamber pushes the moving ring 210 to generate an axial displacement tendency. This displacement is transmitted to the collar 322 through the moving ring 210, which drives the baffle 331 to rotate and triggers the upper transmission link, so that the squeezing force of the extrusion ring 341 on the second sealing ring 231 increases synchronously with the fluid pressure, realizing the adaptive matching of the sealing pressure and the operating pressure, and effectively blocking the leakage of high pressure fluid.

[0038] Working principle: When the turbine pump is running, the elastic element 320 applies axial clamping force to the moving ring 210 through the collar 322, so that the moving ring 210 and the sealing area 240 of the stationary ring 220 are tightly fitted to achieve basic sealing; Meanwhile, the spoiler 331 of the auxiliary support 330 provides radial support for the elastic element 320, preventing the elastic element 320 from shifting due to centrifugal force; When the rotating ring 210 needs axial compensation due to wear, the inner and outer cylinders of the telescopic cylinder 310 move relative to each other, providing precise guidance for the rotating ring 210. During this process, the baffle 331 moves with the collar 322 and is squeezed by the oil in the housing 100 during centrifugal rotation, thus causing it to shift. This assists in the expansion and contraction of the telescopic cylinder 310 and provides elastic protection for the elastic element 320. During its shifting rotation, the transmission gear 343, which is fixedly connected to one end, meshes with the rack frame 342, driving the compression ring 341 to move axially and compress the second sealing ring 231. This makes the second sealing ring 231 fit more tightly with the pump shaft and the inner wall of the moving ring, thereby achieving a linkage enhancement of sealing performance.

[0039] In the description of this invention, it should be understood that the terms "center", "front", "rear", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting the scope of protection of this invention.

[0040] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the foregoing; the descriptions above and in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of this invention is defined by the appended claims and their equivalents.

Claims

1. A mechanical seal structure for a turbopump, sleeved outside the pump shaft, characterized in that, include: The housing (100) includes a sleeve (110) and an end cap (120) that is sealed to one end of the sleeve (110). The ring mechanism (200) is located inside the housing (100) and includes a moving ring (210) and a stationary ring (220) sleeved on the pump shaft, as well as a seal (230). The rotating ring (210) is sealed and fixed to the pump shaft through the sealing element (230) and is clearance-fitted with the sleeve (110); The stationary ring (220) is sealed and fixed to the end cap (120) by the sealing element (230); An elastic compensation component (300), disposed between the moving ring (210) and the sleeve (110), includes: The telescopic cylinder (310), sleeved on the pump shaft and having an inner cylinder and an outer cylinder that can move relative to each other axially, is used to provide axial displacement guidance for the dynamic ring (210); An elastic element (320) is sleeved on the outside of the telescopic cylinder (310) and is used to provide axial clamping force to the moving ring (210); An auxiliary support member (330) is disposed between the telescopic cylinder (310) and the elastic member (320) for radially supporting the elastic member (320). A sealing reinforcement (340) is disposed at one end of the telescopic cylinder (310) and is connected to the auxiliary support (330) for axially pressing the sealing member (230) to enhance the seal.

2. The mechanical seal structure for a turbine pump according to claim 1, characterized in that: A sealing ring (130) is provided between the mating surfaces of the sleeve (110) and the end cap (120), and the cross-section of the sealing ring (130) is cross-shaped.

3. The mechanical seal structure for a turbine pump according to claim 1, characterized in that: A pressure bearing (111) is installed at one end of the sleeve (110) facing the telescopic cylinder (310). A first sealing ring (112) is pressed between the pressure bearing (111) and the sleeve (110). The first sealing ring (112) has an L-shaped cross section and is sleeved on the pump shaft.

4. The mechanical seal structure for a turbine pump according to claim 3, characterized in that: The first sealing ring (112) has multiple through holes on the end face that contacts the telescopic cylinder (310).

5. The mechanical seal structure for a turbine pump according to claim 1, characterized in that: The sealing end faces of the moving ring (210) and the stationary ring (220) are respectively an outward convex stepped surface and an inward concave stepped surface. Both the outward convex stepped surface and the inward concave stepped surface include an inner sealing area (240) and an outer flow guiding area (250). The edge of the flow guiding area (250) is chamfered.

6. The mechanical seal structure for a turbine pump according to claim 1, characterized in that: The seal (230) includes: The second sealing ring (231) is trumpet-shaped and is embedded in the inner wall of the moving ring (210), and is sealed to the pump shaft and the sealing reinforcement (340) respectively. The third sealing ring (232) is wavy and is fitted on the outer wall of the stationary ring (220) and sealed to the end cap (120).

7. The mechanical seal structure for a turbine pump according to claim 6, characterized in that: The second sealing ring (231) has a sealed cavity at the flared end, and the sealed cavity is filled with lubricant.

8. The mechanical seal structure for a turbine pump according to claim 1, characterized in that: The elastic element (320) includes a helical spring ring (321) and collars (322) respectively sleeved on both ends of the spring ring (321). The helical spring ring (321) is composed of an inner spring ring and an outer spring ring sleeved and connected. The end face of the collar (322) that contacts the telescopic cylinder (310) is provided with a rubber layer.

9. A mechanical seal structure for a turbine pump according to claim 1 or 8, characterized in that: The auxiliary support (330) includes a plurality of circumferentially distributed spoilers (331), one end of which is rotatably connected to the outer cylinder of the telescopic cylinder (310), and the other end is slidably connected to the collar (322) through a sliding column (332).

10. A mechanical seal structure for a turbine pump according to claim 6, characterized in that: The sealing reinforcement (340) includes a compression ring (341), a rack frame (342), and a transmission gear (343). The compression ring (341) abuts against the flared end of the second sealing ring (231); The rack frame (342) consists of multiple rack frames, which are uniformly fixed to the side wall of the extrusion ring (341) along the circumference and slide in cooperation with the outer cylinder of the telescopic cylinder (310). The transmission gear (343) is fixed to the shaft end of the auxiliary support (330) and meshes with the rack frame (342).

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