Single mechanical seal for pumps

Abstract

The application discloses a single-end-face built-in mechanical seal for a pump and belongs to the technical field of mechanical seals for liquid pumps. The single-end-face built-in mechanical seal comprises a shell, a ring body mechanism and an elastic compensation assembly. The inner sleeve of the telescopic cylinder is fixed with the pump shaft, the outer sleeve is connected with the dynamic ring, the telescopic cylinder is synchronously driven to slide when being axially telescoped, the expansion rods which are evenly distributed in the circumferential direction of the sliding cylinder are synchronously swung at the same angle and the same amplitude, and then all the extrusion pieces arranged in the circumferential direction are synchronously moved, so that the radial and axial components of the extrusion rods of each group applied to the inner wall of the telescopic cylinder are completely consistent. The elastic piece is adopted to synchronously generate the support force for the dynamic ring in the whole circumferential direction and the support force is uniformly distributed. No matter whether the telescopic cylinder is elongated or shortened, the dynamic ring can always keep the parallel and adhering state with the static ring, and the problems of the dynamic ring deflection and the local excessive wear of the end face are fundamentally eliminated.

Description

Technical Field

[0001] This invention relates to the field of mechanical seal technology for liquid pumps, and more specifically, to a single-end-face internal mechanical seal for pumps. Background Technology

[0002] Mechanical seals are critical components in preventing leakage between the pump shaft and the housing of a liquid pump. Their sealing performance and service life directly affect the safety and operating efficiency of the pump unit. In single-end-face internal mechanical seal structures, elastic compensation components are usually required to maintain a continuous tight fit between the sealing end faces of the dynamic and static rings to compensate for end face wear and axial movement during operation.

[0003] Currently, traditional elastic compensation components mostly use spring elements to provide axial clamping force. Their typical structure and corresponding defects are as follows: Single-spring structure: This structure uses a single, relatively large helical spring fitted onto the pump shaft. The main problem with this structure is that the clamping force it provides is concentrated in the circumferential area where the spring is located, and cannot be evenly distributed throughout the entire circumference of the rotating ring. This uneven force distribution can easily lead to the rotation of the rotating ring, which in turn causes excessive localized wear on the sealing end face, accumulation of frictional heat, increased leakage risk, and significantly shortened seal service life.

[0004] Multi-spring structure: Employs multiple independent, circumferentially distributed small helical springs. Although this design aims to improve the circumferential distribution of support force, it places extremely high demands on the machining accuracy, material performance consistency, and assembly precision of each spring. In practical applications, even minute manufacturing tolerances or fatigue differences caused by long-term operation can make it difficult to maintain consistency in the elastic coefficient and deformation of each spring. This inevitably leads to uneven pressure on the dynamic ring end face and uneven wear, making it difficult to fully guarantee its support stability and long-term reliability.

[0005] It is evident that existing elastic compensation schemes relying on single or multiple independent spring elements generally suffer from problems such as unstable stress state of the sealing surface, accelerated wear, and limited service life due to uneven circumferential distribution of support force or individual elasticity differences.

[0006] Therefore, it is necessary to improve the elastic compensation structure of mechanical seals to overcome the above-mentioned defects.

[0007] In view of this, a single-end-face internal mechanical seal for pumps is proposed. Summary of the Invention

[0008] The purpose of this invention is to provide a single-end-face internal mechanical seal for pumps, in order to solve the problems mentioned in the background art.

[0009] This invention provides the following technical solution: a single-end-face internal mechanical seal for pumps, comprising: case; The ring mechanism, located inside the housing, includes a rotating ring that rotates with the pump shaft and a stationary ring that remains stationary. The end faces of the rotating ring and the stationary ring are fitted together to form a sealing pair. The resilient compensation component includes: A telescopic cylinder is sleeved on the outside of the pump shaft, with one end connected to the dynamic ring. The telescopic cylinder can extend and retract axially. An elastic element, located inside the telescopic cylinder, is used to apply an axial clamping force to the moving ring; A synchronous guide is disposed inside the telescopic cylinder and located between the elastic element and the cylinder wall of the telescopic cylinder. The synchronous guide connects the telescopic cylinder and the elastic element and is configured to drive the elastic element to generate a synchronous and uniform elastic support force on the moving ring in the circumferential direction when the telescopic cylinder extends or retracts axially.

[0010] According to the above technical solution, the telescopic cylinder includes an inner sleeve and an outer sleeve that can move relative to each other axially. The inner sleeve is fixedly connected to the pump shaft, and the outer sleeve is connected to the moving ring. The synchronization guide includes a slide cylinder, which is slidably fitted inside the inner sleeve and the outer sleeve.

[0011] According to the above technical solution, the synchronous guide further includes: two limiting rings, which are respectively fixed to both ends of the slide cylinder and respectively accommodated in the internal cavities of the inner sleeve and the outer sleeve; Multiple expansion rods are spaced apart circumferentially, with the first end of each expansion rod hinged to the slide cylinder and the second end connected to the elastic element.

[0012] According to the above technical solution, the elastic element includes: A constraint ring seat is fitted onto the outside of the slide cylinder; Multiple sets of extrusion members are arranged circumferentially on the constraint ring seat, and each extrusion member is hinged to the second end of the corresponding expansion rod.

[0013] According to the above technical solution, each set of extrusion components includes: The slide block is slidably disposed in the limiting groove of the constraint ring seat along the axial direction; Two extrusion rods are arranged symmetrically. The first end of each extrusion rod is hinged to the slide block, and the second end is hinged to the inner wall of the telescopic cylinder and the second end of the expansion rod, respectively.

[0014] According to the above technical solution, the elastic element further includes a damping element, which is sleeved on the constraint ring seat and connected to each of the slide seats to buffer the sliding of the slide seats.

[0015] According to the above technical solution, the damping element includes: The pressure ring cylinder is under negative pressure inside. Multiple telescopic pistons are distributed circumferentially and communicate with the inside of the pressure ring cylinder. The telescopic end of each telescopic piston is fixedly connected to the corresponding slide.

[0016] According to the above technical solution, a negative pressure regulator is provided on the pressure ring cylinder to adjust the pressure inside the pressure ring cylinder.

[0017] According to the above technical solution, the inner sleeve and the outer sleeve are sealed together by a sealing strip, and the sealing strip is spirally wrapped in the sealing groove on the outer wall of the inner sleeve.

[0018] According to the above technical solution, the ring mechanism further includes a sealing element, the sealing element comprising: The first sealing ring is an expandable gas ring filled with gas, and its inner wall has a pulley-like structure that is narrow in the middle and wide at both ends. The second sealing ring is fitted over the outside of the stationary ring.

[0019] Compared with the prior art, the beneficial effects of the present invention, using the above technical solution, are as follows: 1. In this invention, the inner sleeve of the telescopic cylinder is fixed to the pump shaft, and the outer sleeve is connected to the rotating ring. During axial extension and contraction, it synchronously drives the inner slide cylinder to slide. The circumferentially distributed expansion rods of the slide cylinder will swing synchronously at the same angle and amplitude, thereby linking all the circumferentially arranged extrusion parts to move synchronously, so that the radial and axial components of each extrusion rod are completely consistent on the inner wall of the telescopic cylinder. The linkage mechanism makes the supporting force of the elastic element on the rotating ring synchronously generated and evenly distributed in the entire circumferential direction. No matter whether the telescopic cylinder is extended or shortened, the rotating ring can always maintain a parallel and close fit with the stationary ring, eliminating the problem of rotating ring skew and excessive wear of the end face from the root. At the same time, this linkage structure does not rely on the consistent matching of high-precision springs, which greatly reduces the difficulty of processing and assembly. During long-term operation, there will be no problem of force imbalance caused by fatigue difference of elastic elements, which keeps the contact pressure of the sealing pair stable, effectively reduces the generation of frictional heat, reduces the risk of medium leakage, significantly improves the operational stability and service life of the mechanical seal, and is suitable for the working conditions of long-term continuous operation of liquid pumps.

[0020] 2. The inner sleeve and outer sleeve of the telescopic cylinder of this invention are sealed with a spiral sealing strip. This structure can not only ensure the dynamic sealing effect when the outer sleeve slides axially relative to the inner sleeve, but also effectively prevent external media and impurities from entering the telescopic cylinder. This avoids the problems of jamming and malfunction of the synchronous guide and elastic components due to contamination, and provides a clean internal environment for the stable operation of the elastic compensation component. At the same time, the negative pressure ring of the damping component is linked with the circumferential telescopic piston. Each telescopic piston is fixedly connected to the slide of the extrusion component. When the slide slides axially with the elastic compensation action, the negative pressure ring generates uniform damping resistance, buffering the sliding impact of the slide and suppressing the vibration of the moving ring caused by pump shaft jump and medium pressure pulsation. The linkage of the two forms a double guarantee of "external sealing protection + internal vibration reduction and stabilization", which makes the elastic compensation action smooth and jump-free. The contact pressure of the sealing end face will not change suddenly due to pump shaft movement. This avoids gap leakage of the sealing pair due to impact and also prevents overload wear.

[0021] 3. This invention forms a sealing system through the linkage of the elastic compensation component and the ring mechanism seal, solving the problems of high frictional resistance and poor dynamic tracking performance of traditional auxiliary seals. Traditional mechanical seals rely solely on elastic elements to compensate for end face wear, and the auxiliary sealing rings are mostly ordinary O-rings. Under high-speed rotation and slight radial runout of the pump shaft, these are prone to frictional overheating and seal failure. In contrast, in this invention, the elastic compensation component continuously provides uniform and stable axial clamping force, ensuring that the precision-ground end faces of the rotating and stationary rings are always tightly fitted, thus strengthening the core sealing defense of the main sealing pair and effectively compensating for the wear of the sealing end face over long-term operation and the axial movement clearance of the pump shaft. Meanwhile, the first sealing ring of the ring mechanism adopts an internally inflatable gas ring with a pulley-like structure that is narrow in the middle and wide at both ends. This structure works in conjunction with the uniform support of the elastic compensation component: the expandable gas ring can adaptively conform to the pump shaft surface, and the pulley-like inner wall ensures sufficient sealing contact area while significantly reducing the frictional resistance when the pump shaft rotates. Even if there is a small radial runout of the pump shaft, it can maintain good dynamic tracking and avoid media leakage along the pump shaft surface. This solves the problems of auxiliary seal failure and frictional overheating of traditional seals under high-speed and radial runout conditions, further improving the overall reliability and long service life of the mechanical seal. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the overall structure of the present invention; Figure 2 This is a half-sectional schematic diagram of the overall structure of the present invention; Figure 3 This is a half-sectional view of the telescopic cylinder structure of the present invention; Figure 4 This is a half-sectional view of the ring mechanism structure of the present invention. Figure 5This is a cross-sectional view of the first sealing ring structure of the present invention; Figure 6 This is a cross-sectional schematic diagram of the elastic element structure of the present invention; Figure 7 This is a schematic diagram of the constraint ring seat structure of the present invention; Figure 8 This is a cross-sectional schematic diagram of the extrusion component structure of the present invention; Figure 9 This is a cross-sectional schematic diagram of the damping component structure of the present invention; Figure 10 This is a schematic diagram of the synchronous guide component structure of the present invention.

[0023] Explanation of the numbers in the diagram: 100, shell; 110, liquid cooling sleeve; 120, end cap; 200, ring mechanism; 210, moving ring; 220, stationary ring; 230, sealing element; 231, first sealing ring; 232, second sealing ring; 300, elastic compensation component; 310, telescopic cylinder; 311, inner sleeve; 312, outer sleeve; 313, sealing strip; 320, elastic element; 321, constraint ring seat; 322, extrusion element; 323, damping element; 324, slide; 325, extrusion rod; 326, pressure ring cylinder; 327, telescopic piston; 328, negative pressure regulator; 330, synchronous guide; 331, slide; 332, limit ring; 333, expansion rod. Detailed Implementation

[0024] 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.

[0025] Please see Figures 1 to 10 The present invention provides a single-end face internal mechanical seal for pumps, which is sleeved on the outside of the pump shaft; the mechanical seal is mainly composed of three parts: housing 100, ring mechanism 200 and elastic compensation component 300.

[0026] like Figure 1 and Figure 2As shown, the housing 100 serves as the mounting base and protective shell for the entire sealing device. Its interior contains a chamber for accommodating the ring mechanism 200 and the elastic compensation component 300. One end of the housing 100 can be sealed to the pump cover or similar fixed component, while the other end can be sealed with an end cap 120. An integrated liquid-cooling sleeve 110 surrounds the housing 100. The liquid-cooling sleeve 110 has a spiral or annular coolant flow channel machined inside. Coolant inlets and outlets are located at both ends of the flow channel. During use, an external cooling circulation system is connected, allowing the flow of coolant such as cooling water or heat transfer oil to continuously remove the heat generated by the friction pair between the moving ring 210 and the stationary ring 220. This prevents thermal deformation, thermal cracking, and burning of the sealing surface due to high temperatures on the sealing end face, ensuring stable operation of the sealing pair within a suitable temperature range.

[0027] like Figure 2 and Figure 4 As shown, the ring mechanism 200 is disposed inside the housing 100 and mainly includes a rotating ring 210 and a stationary ring 220. The rotating ring 210 is fixedly connected to the pump shaft through a transmission mechanism (such as a set screw or a drive pin) and rotates synchronously with the pump shaft. The stationary ring 220 is kept circumferentially stationary relative to the housing 100 by an anti-rotation pin or other positioning structure, but it may have a small floating space in the axial direction. The end faces of the rotating ring 210 and the stationary ring 220 are precision ground and polished, and they fit tightly together under the axial clamping force provided by the elastic compensation component 300 to form a main sealing pair that prevents the sealed medium from leaking along the axial direction.

[0028] like Figure 2 , Figure 3 and Figure 5 As shown, the elastic compensation component 300 includes a telescopic cylinder 310, an elastic element 320, and a synchronous guide 330; the main function of this component is to provide a continuous and uniform axial compensation force to overcome the wear of the end faces of the rotating ring 210 and the stationary ring 220 during operation and the axial movement of the pump shaft. The telescopic sleeve 310 serves as the external support and transmission structure for the elastic compensation component. It is fitted onto the outside of the pump shaft and is made of thin-walled stainless steel, possessing good axial extensibility and structural strength. It consists of an inner sleeve 311 and an outer sleeve 312, which can slide relative to each other axially to achieve the telescopic function. The inner sleeve 311 is directly fitted onto the outside of the pump shaft and rigidly fixed to it via set screws, bushings, or clamps, rotating synchronously with the pump shaft. Its outer wall is machined with a spiral sealing groove, the depth and width of which precisely match the sealing strip 313. One end of the outer sleeve 312 is rigidly connected to the rotating ring 210, while the other end can slide. Attached to the outside of the inner sleeve 311, it rotates with the inner sleeve 311 and can slide along the axial direction of the inner sleeve 311, driving the moving ring 210 to complete end face wear compensation; the sealing strip 313 is made of polytetrafluoroethylene, flexible graphite or carbon fiber composite material, which has the characteristics of self-lubrication, wear resistance and excellent sealing performance. It is tightly wrapped in the sealing groove on the outer wall of the inner sleeve 311 in a spiral shape. The spiral structure can ensure dynamic sealing when the outer sleeve 312 slides axially relative to the inner sleeve 311, effectively preventing the medium and impurities from entering the interior of the telescopic cylinder 310, and avoiding the synchronous guide 330 and elastic element 320 from getting stuck or malfunctioning due to contamination.

[0029] like Figure 5 , Figure 6 and Figure 10 As shown, the synchronous guide 330 is the core transmission component for achieving circumferential synchronous movement. It is installed inside the telescopic cylinder 310, located between the elastic element 320 and the cylinder wall of the telescopic cylinder 310. It consists of a sliding cylinder 331, a limiting ring 332, and a support rod 333, ensuring that the elastic compensation force is evenly distributed in the full circumference of the moving ring. The sliding cylinder 331 is cylindrical in shape and is slidably fitted inside the inner sleeve 311 and the outer sleeve 312, serving as the central support of the entire guide mechanism. The two limiting rings 332 are fixed to the axial ends of the sliding cylinder 331 by threads or snap rings, and are respectively restricted within the inner sleeve 311 and the outer sleeve 312. The internal cavity of the sleeve 312 is used to limit the axial sliding stroke of the slide cylinder 331 relative to the telescopic cylinder 310 and prevent the slide cylinder 331 from falling out. The slide cylinder 331 is evenly spaced (≥6 groups) along its circumference and adopts a high-strength alloy rod structure. The first end of each expansion rod 333 is hinged to the outer wall of the slide cylinder 331 through a precision hinge shaft and can swing freely in the radial plane. The second end is hinged to the elastic element 320. When the slide cylinder 331 slides, all expansion rods 333 swing synchronously with the same angle and the same amplitude, so as to achieve complete synchronization of circumferential movement and enable it to swing in the radial plane of the slide cylinder 331.

[0030] like Figures 5 to 8As shown, the elastic element 320 is the core component providing axial clamping force. It is installed inside the telescopic cylinder 310, between the inner walls of the slide cylinder 331 and the outer sleeve 312. It consists of a constraint ring seat 321, an extruder 322, and a damping element 323, replacing the traditional spring. It has no elastic fatigue difference and uniform force distribution. The constraint ring seat 321 is ring-shaped and is fitted and fixed to the outer circumferential surface of the slide cylinder 331. Multiple axially extending limiting grooves are formed on its outer circumferential surface. Multiple sets of extruders 322 are arranged one-to-one in the limiting grooves of the constraint ring seat 321 along the circumferential direction. Each set of extruders 322 has... It includes a slide block 324 and two extrusion rods 325; the bottom of the slide block 324 is slidably engaged with the limiting groove and can slide along the axial direction of the constraint ring seat 321; the two extrusion rods 325 are arranged in a left-right symmetrical "V" or "V" shape structure, and the first end (lower end) of each extrusion rod 325 is hinged to the top of the slide block 324, and its second end (upper end) is hinged to the inner wall of the outer sleeve 312 of the telescopic cylinder 310 and the second end of the aforementioned expansion rod 333, respectively, so that the change of radial space of the telescopic cylinder 310 is converted into the axial sliding of the slide block 324 by the swing of the extrusion rods 325.

[0031] like Figure 6 , Figure 8 and Figure 9 As shown, to buffer the impact and vibration of the slide 324 during axial sliding, the elastic element 320 is also equipped with a damping element 323. The damping element 323 is sleeved on the constraint ring seat 321 and specifically includes a sealed pressure ring cylinder 326 and multiple telescopic pistons 327. The pressure ring cylinder 326 is an annular sealed cavity with an internal negative pressure state. The negative pressure regulator 328 is a miniature air nozzle or one-way valve structure, installed on the outer wall of the pressure ring cylinder 326. It can adjust the magnitude of the negative pressure inside the pressure ring cylinder 326 according to the pump's operating conditions, thereby adjusting the damping force intensity to adapt to different speeds and pressures. The pump body operates as follows: Multiple telescopic pistons 327 are distributed circumferentially along the pressure ring cylinder 326, and their internal chambers are connected to the interior of the pressure ring cylinder 326. The telescopic end (piston rod end) of each telescopic piston 327 is fixedly connected to the corresponding slide 324. When the slide 324 slides due to the elastic compensation action, it will drive the telescopic piston 327 to perform telescopic movement. At this time, the negative pressure in the pressure ring cylinder 326 will provide resistance to this movement, thereby playing a damping and buffering role, effectively suppressing the vibration of the moving ring 210 caused by pump shaft jump or medium pressure pulsation, and making the sealing end face run more smoothly.

[0032] Furthermore, such as Figure 4As shown, to improve the auxiliary sealing reliability of the ring mechanism 200 during dynamic compensation, the ring mechanism 200 also includes a sealing element 230; the sealing element 230 includes a first sealing ring 231 and a second sealing ring 232; the first sealing ring 231 is disposed between the moving ring 210 and the pump shaft to prevent medium leakage along the surface of the pump shaft; the first sealing ring 231 is an expandable gas ring filled with inert gas, made of fluororubber or silicone rubber, which has the characteristics of temperature resistance, corrosion resistance and high elasticity; its inner wall is designed as a pulley-like structure that is narrow in the middle and wide at both ends, and can adaptively fit the surface of the pump shaft after inflation, ensuring sufficient sealing contact area and significantly reducing leakage. The low frictional resistance during pump shaft rotation ensures good dynamic tracking even with slight radial runout, preventing overheating and seal failure. When the pump shaft rotates at high speed or experiences slight radial runout, this pulley-like inner wall structure guarantees sufficient contact area and adhesion to maintain the seal while reducing frictional resistance and providing excellent tracking. The second sealing ring 232, using a standard O-ring or wedge-shaped sealing ring, is fitted into the sealing groove outside the stationary ring 220 to achieve a static seal between the stationary ring 220 and the inner wall of the housing 100. This simple and reliable structure is used to achieve a static seal between the stationary ring 220 and the inner wall of the housing 100.

[0033] The working principle of this invention is: When the pump starts, the pump shaft drives the inner sleeve 311 to rotate. The inner sleeve 311 drives the outer sleeve 312 and the moving ring 210 to rotate synchronously through the friction of the spiral sealing strip 313 and the circumferential limiting effect of the synchronous guide 330. At this time, under the initial pre-tightening force of the elastic element 320, the two sets of symmetrically arranged extrusion rods 325 apply axial thrust to the slide 324, and the reaction force is evenly transmitted to the end face of the outer sleeve 312 through the constraint ring seat 321, thereby pressing the moving ring 210 on the end face of the stationary ring 220 to form an initial seal. During long-term operation, the sealing end faces of the rotating ring 210 and the stationary ring 220 will experience slight wear due to friction. At this time, in order to compensate for the wear gap, the elastic potential energy stored inside the elastic element 320 is released, pushing the slide 324 to move forward (axially) along the limiting groove of the constraint ring seat 321. The movement of the slide 324 pushes the outer sleeve 312 and the rotating ring 210 to follow through the extrusion rod 325, so as to eliminate the wear gap. During this compensation displacement process, the outer sleeve 312 slides axially relative to the inner sleeve 311. This relative sliding drives the synchronous guide 330 to move: the slide cylinder 331 slides inside the inner sleeve 311, causing the support angle of the expansion rod 333 to change synchronously; since all the expansion rods 333 are connected to the same slide cylinder 331 and are evenly distributed circumferentially, their swing angles are completely consistent; the swing of the expansion rods 333 synchronously and equally adjusts the support arm and angle of the corresponding position compression rod 325 through the hinge point. Specifically, regardless of whether the telescopic cylinder 310 extends or shortens, the expansion rod 333 will synchronously drive all the circumferentially arranged extrusion parts 322, causing their slide blocks 324 to produce the same axial displacement increment. This ensures that the radial and axial components of the force applied by each set of extrusion rods 325 to the inner wall of the telescopic cylinder 310 remain highly consistent, guaranteeing that the elastic support force is always synchronous and uniform in the entire circumferential direction of the moving ring 210. Even when the pump shaft experiences slight axial movement, the negative pressure ring 326 of the damping element 323 provides uniform damping resistance through the telescopic piston 327, buffering the sliding impact of the slide block 324 and suppressing the vibration of the rotating ring; the spiral sealing strip 313 continuously blocks impurities, ensuring the clean operation of internal components; the expandable gas ring type first sealing ring 231 adaptively fits the pump shaft, reducing frictional resistance and achieving dynamic sealing; ultimately, through the synergistic work of the above structures, the present invention effectively avoids the problem of uneven end face pressure caused by spring fatigue differences or processing errors, significantly reduces the risk of uneven wear of the rotating ring, and improves the operational stability and service life of the mechanical seal.

[0034] 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 accompanying 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.

[0035] 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 single-end-face internal mechanical seal for pumps, sleeved outside the pump shaft, characterized in that, include: Casing (100); The ring mechanism (200) is located inside the housing (100) and includes a rotating ring (210) that rotates with the pump shaft and a stationary ring (220) that remains stationary. The end faces of the rotating ring (210) and the stationary ring (220) are fitted together to form a sealing pair. The resilient compensation component (300) includes: The telescopic cylinder (310) is sleeved on the outside of the pump shaft, and one end of it is connected to the moving ring (210). The telescopic cylinder (310) can extend and retract axially. An elastic element (320) is disposed inside the telescopic cylinder (310) and is used to apply an axial clamping force to the moving ring (210); A synchronous guide (330) is disposed inside the telescopic cylinder (310) and located between the elastic element (320) and the cylinder wall of the telescopic cylinder (310). The synchronous guide (330) connects the telescopic cylinder (310) and the elastic element (320) and is configured to drive the elastic element (320) to generate a synchronous and uniform elastic support force on the moving ring (210) in the circumferential direction when the telescopic cylinder (310) extends or retracts axially.

2. The single-end-face internal mechanical seal for pumps according to claim 1, characterized in that: The telescopic cylinder (310) includes an inner sleeve (311) and an outer sleeve (312) that are movable relative to each other in the axial direction. The inner sleeve (311) is fixedly connected to the pump shaft, and the outer sleeve (312) is connected to the moving ring (210). The synchronization guide (330) includes a slide cylinder (331), which is slidably fitted inside the inner sleeve (311) and the outer sleeve (312).

3. A single-end-face internal mechanical seal for pumps according to claim 2, characterized in that: The synchronous guide (330) further includes: two limiting rings (332), which are respectively fixed to both ends of the slide (331) and respectively accommodated in the internal cavities of the inner sleeve (311) and the outer sleeve (312); Multiple expansion rods (333) are spaced apart circumferentially. The first end of each expansion rod (333) is hinged to the slide cylinder (331), and the second end is connected to the elastic element (320).

4. A single-end-face internal mechanical seal for pumps according to claim 3, characterized in that: The elastic element (320) includes: A constraint ring seat (321) is sleeved on the outside of the slide cylinder (331); Multiple sets of extrusion members (322) are arranged circumferentially on the constraint ring seat (321), and each extrusion member (322) is hinged to the second end of the corresponding expansion rod (333).

5. A single-end-face internal mechanical seal for pumps according to claim 4, characterized in that: Each set of extrusions (322) includes: The slide (324) is slidably disposed in the limiting groove of the constraint ring seat (321) along the axial direction; Two extrusion rods (325) are arranged in a symmetrical structure. The first end of each extrusion rod (325) is hinged to the slide (324), and the second end is hinged to the inner wall of the telescopic cylinder (310) and the second end of the expansion rod (333), respectively.

6. A single-end-face internal mechanical seal for pumps according to claim 5, characterized in that: The elastic element (320) further includes a damping element (323), which is sleeved on the constraint ring seat (321) and connected to each of the slides (324) to buffer the sliding of the slides (324).

7. A single-end-face internal mechanical seal for pumps according to claim 6, characterized in that: The damping element (323) includes: The pressure ring cylinder (326) is under negative pressure inside; Multiple telescopic pistons (327) are distributed circumferentially and communicate with the inside of the pressure ring cylinder (326). The telescopic end of each telescopic piston (327) is fixedly connected to the corresponding slide (324).

8. A single-end-face internal mechanical seal for pumps according to claim 7, characterized in that: The pressure ring cylinder (326) is equipped with a negative pressure regulator (328) for adjusting the pressure inside the pressure ring cylinder (326).

9. A single-end-face internal mechanical seal for pumps according to claim 2, characterized in that: The inner sleeve (311) and the outer sleeve (312) are sealed together by a sealing strip (313), which is spirally wrapped in the sealing groove on the outer wall of the inner sleeve (311).

10. A single-end-face internal mechanical seal for pumps according to any one of claims 1-9, characterized in that: The ring mechanism (200) further includes a seal (230), the seal (230) comprising: The first sealing ring (231) is an expandable gas ring filled with gas inside, and its inner wall has a pulley-like structure that is narrow in the middle and wide at both ends. The second sealing ring (232) is fitted over the outside of the stationary ring (220).

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