An improved sealing structure

Abstract

The present application relates to the technical field of mechanical seals, and in particular to an improved sealing structure, which includes a seal seat, a rotating shaft, a mechanical seal assembly, a first lip seal ring, and a force applying assembly; wherein the rotating shaft is rotatably connected to the seal seat; the mechanical seal assembly includes a stationary ring, a rotating ring, and an elastic member; the mechanical seal assembly includes a stationary ring, a rotating ring, and an elastic member, and the stationary ring is sealingly connected to the seal seat; the rotating ring is sealingly and slidably arranged on the rotating shaft, and one side of the rotating ring close to the medium to be sealed is rotationally abutted against one side of the stationary ring; the outer wall of the first lip seal ring is sealingly connected to the seal seat, the lip edge of the first lip seal ring slidably abuts against the outer wall of the rotating shaft, and a first sealing cavity is formed between the first lip seal ring and the mechanical seal assembly; the force applying assembly can increase the abutting force of the rotating ring against the stationary ring and the pressure in the first sealing cavity in direct proportion to the centrifugal force generated by rotation. The present application has the effects of improving the sealing effect of the sealing device and reducing the influence of centrifugal force on its sealing performance.

Description

Technical Field

[0001] This application relates to the technical field of mechanical seals, and in particular, to an improved seal structure. Background Art

[0002] The final polymerization kettle is an important device for the synthesis of polymer materials and is widely used in the production processes of polymers such as polyester and polyurethane. Such devices play a key role in industrial production as they can effectively control the reaction conditions to ensure product quality and production safety. However, due to the complex and variable internal environment of the final polymerization kettle, it often faces the influence of high temperature, high pressure, and corrosive media, which pose extremely high requirements for the reliability and safety of the equipment, especially in terms of the sealing performance at the rotational connection of the stirring shaft; good sealing can not only ensure the smooth progress of the process flow but also significantly extend the service life of the equipment, reduce the maintenance frequency, and improve the overall production efficiency.

[0003] In the prior art, to address these challenges, a sealing structure uses a combination of a lip seal and an externally mounted mechanical seal at the rotational connection of the stirring shaft. The lip seal achieves initial static or dynamic sealing at low rotational speeds through the tight contact of its flexible lip part with the shaft surface; while the externally mounted mechanical seal installs the stationary ring outside the seal gland and utilizes the precise fit between the rotating ring and the stationary ring to maintain the dynamic sealing effect under high pressure, high temperature, and high rotational speeds through the action of a spring.

[0004] Although the above technology meets the basic sealing requirements to a certain extent, there are still obvious deficiencies. Especially at high rotational speeds, the lip part of the lip seal will be subjected to a strong centrifugal force, causing the lip to stretch outward, reducing the contact pressure with the shaft, and thus reducing the sealing effect; the externally mounted mechanical seal will also experience leakage of the sealing medium from the contact gap between the rotating ring and the stationary ring under the action of centrifugal force, seriously affecting the stability and reliability of the system. Summary of the Invention

[0005] In order to improve the sealing effect and stability of the sealing device and reduce the influence of centrifugal force on its sealing performance, this application provides an improved seal structure.

[0006] The improved seal structure provided by this application adopts the following technical solutions:

[0007] An improved seal structure, comprising:

[0008] A seal seat;

[0009] A rotating shaft, the rotating shaft is rotatably connected to the seal seat;

[0010] A mechanical seal assembly, the mechanical seal assembly comprising a stationary ring, a dynamic ring and an elastic member, the stationary ring is seal-connected to a seal seat; the dynamic ring is seal-slidably arranged on a rotating shaft, and the sliding direction of the dynamic ring is parallel to the rotation axis of the rotating shaft; the side of the dynamic ring close to the sealed medium is rotationally abutted against one side of the stationary ring, and the centrifugal force direction of the rotating shaft is the same as the leakage direction of the sealed medium when it leaks from between the dynamic ring and the stationary ring; the elastic member is used to provide a certain abutment force for the dynamic ring to rotate and abut against the stationary ring;

[0011] A first lip-shaped sealing ring, wherein the outer wall of the first lip-shaped sealing ring is sealingly connected to the sealing seat, the lip edge of the first lip-shaped sealing ring slides against the outer wall of the rotating shaft, the first lip-shaped sealing ring is located at a side of the mechanical sealing assembly away from the sealed medium, and the lip of the first lip-shaped sealing ring faces the mechanical sealing assembly, and a first sealing cavity is formed between the first lip-shaped sealing ring and the mechanical sealing assembly;

[0012] The force-adding component is arranged on the rotating shaft and rotates together with the rotating shaft. The force-adding component can increase the contact force of the dynamic ring on the static ring and increase the pressure in the first sealing cavity in direct proportion to the centrifugal force generated by the rotation.

[0013] By adopting the above technical scheme, the improved sealing structure can effectively improve the sealing performance and sealing stability under high-speed rotation conditions, and reduce the influence of centrifugal force on its sealing performance; specifically, the force-adding component uses the centrifugal force generated by the rotation of the shaft to increase the abutment force of the dynamic ring on the static ring, making the contact between the two closer, and at the same time it can also increase the pressure in the first sealing cavity, so that after the pressure on one side of the lip of the first lip-shaped sealing ring increases, the lip edge of the first lip-shaped sealing ring abuts more closely with the outer wall of the rotating shaft; and the higher the rotation speed of the rotating shaft, the tighter the abutment between the dynamic ring and the static ring, and the tighter the first lip-shaped sealing ring and the outer wall of the rotating shaft; in addition, the double sealing of the first lip-shaped sealing ring and the mechanical sealing assembly combines the advantages of two sealing methods, so that the sealing structure can have good sealing effects both in low-speed static and high-speed dynamic conditions, greatly expanding the application range of the sealing structure, so that it can perform well under a wider range of working conditions.

[0014] Optionally, it also includes a sleeve, which is sleeved on the outside of the rotating shaft and the inner wall of the sleeve is sealingly abutted against the outer wall of the rotating shaft; the lip edge of the first lip sealing ring is slidably abutted against the outer surface of the sleeve.

[0015] By adopting the above technical solution, the first lip seal ring is no longer in direct contact with the rotating shaft, but is in sliding contact with the outer surface of the sleeve; in this way, the sleeve can act as a wearing part, effectively preventing the first lip seal ring from wearing the outer surface of the rotating shaft, and improving the overall reliability and life of the sealing structure.

[0016] Optionally, the boosting component includes a mounting ring, a plurality of centrifugal pushing blocks and an elastic film; the mounting ring is sleeved on the shaft sleeve and rotates together with the rotating shaft, and a plurality of sliding grooves are circumferentially formed in the mounting ring along the rotation axis of the rotating shaft, and the plurality of centrifugal pushing blocks are correspondingly arranged in the plurality of sliding grooves; the centrifugal pushing blocks are wedge-shaped with the narrow ends facing away from the rotating shaft, one end of the elastic member abuts against the end of the moving ring facing away from the stationary ring, and the other end abuts against the wedge-shaped surface of the centrifugal pushing block; the elastic film is arranged in the first sealing cavity, the edge of the elastic film is hermetically connected to the surface of the shaft sleeve and the elastic film is connected to the centrifugal pushing block; when the rotating shaft rotates, the centrifugal pushing blocks can slide along the sliding grooves in the direction away from the rotating shaft under the action of centrifugal force to push the elastic member to move towards the moving ring and make the elastic film bulge to compress the first sealing cavity.

[0017] By adopting the above technical solution, the improved sealing structure can effectively enhance the abutting force between the moving ring and the stationary ring under high-speed rotation conditions, and at the same time further improve the abutting force between the first lip seal and the surface of the rotating shaft by boosting the pressure in the first sealing cavity; specifically, the centrifugal pushing blocks in the boosting component slide along the sliding grooves under the action of the centrifugal force generated when the rotating shaft rotates, pushing the elastic member towards the moving ring, increasing the pressing force of the moving ring on the stationary ring, thereby enhancing the sealing effect; and the centrifugal pushing blocks force the elastic film to bulge, increasing the pressure in the first sealing cavity and the abutting force between the lip edge of the first lip seal and the surface of the rotating shaft, further preventing the leakage of the sealing medium; this design not only improves the overall stability and reliability of the sealing device, but also significantly extends the service life of the equipment and reduces the maintenance cost.

[0018] Optionally, it further includes a plurality of second lip seals sleeved on the outer side of the shaft sleeve in a positive and negative staggered manner, the outer walls of the plurality of second lip seals are hermetically connected to the sealing seat, and the lip edges of the plurality of second lip seals all slide and abut against the outer wall of the shaft sleeve.

[0019] By adopting the above technical solution, the sealing structure further enhances the overall sealing effect by sleeving a plurality of second lip seals on the outer side of the shaft sleeve in a positive and negative staggered manner; the outer wall of each second lip seal is tightly connected to the sealing seat, and its lip edge slides and abuts against the outer wall of the shaft sleeve, forming multiple lines of defense; this design not only improves the reliability of a single sealing point, but also effectively prevents the overall leakage problem caused by the failure of a single seal; in addition, the design of multiple seals enables other seals to continue to function even if a certain seal is damaged, greatly enhancing the stability and safety of the system.

[0020] Optionally, multiple second lip seals are all located on the side of the first lip seal away from the first sealing cavity, and the lip of the second lip seal adjacent to the first lip seal faces away from the first lip seal; a second sealing cavity is formed between the first lip seal and the second lip seal; a communication cavity communicating the second sealing cavity and the side of the elastic membrane away from the first sealing cavity is formed on the shaft sleeve; a negative pressure can be formed in the communication cavity after the elastic membrane bulges.

[0021] By adopting the above technical solution, during the rotation of the rotating shaft, the centrifugal push block pushes the elastic member towards the moving ring under the action of centrifugal force, and at the same time drives the elastic membrane to bulge; after the elastic membrane bulges, it compresses the first sealing cavity, applying an additional pressure to one side of the lip of the first lip seal, enhancing the fitting degree between the first lip seal and the outer wall of the shaft sleeve, and effectively improving the sealing performance at this position; on the other hand, when the elastic membrane bulges, a negative pressure will also be formed in the communication cavity connected to it, and then the negative pressure will be transmitted to the second sealing cavity through the channel opened on the shaft sleeve; this design not only realizes the pressure balance on both sides of the elastic membrane, avoiding structural deformation or failure caused by excessive unilateral force, but also further strengthens the abutting force between the first lip seal and the second lip seal and the outer wall of the shaft sleeve through the negative pressure effect, thereby greatly improving the stability and reliability of the entire sealing system and significantly reducing the risk of medium leakage under high-speed operation conditions.

[0022] Optionally, a third sealing cavity is formed when the lips of adjacent second lip seals face away from each other, and a fourth sealing cavity is formed when the lips face each other; the third sealing cavity communicates with the communication cavity; lubricating oil is filled in the first sealing cavity and the fourth sealing cavity.

[0023] By adopting the above technical solution, when a negative pressure is formed in the communication cavity, a negative pressure will also be generated in the third sealing cavity communicating with it; this negative pressure effect makes the side of the second lip seal away from the lip closely adsorb on the outer wall of the shaft sleeve, enhancing the sealing performance; the lubricating oil in the first sealing cavity and the fourth sealing cavity expands in volume after friction generates heat, and can respectively apply an additional pressure to the first sealing cavity and the fourth sealing cavity, and further make the lips of the first lip seal and the second lip seal abut more closely against the outer wall of the shaft sleeve, enhancing the sealing performance; in addition, the presence of the lubricating oil effectively reduces the frictional resistance between the first lip seal, the second lip seal and the outer wall of the shaft sleeve, improving the smoothness and durability of the overall operation.

[0024] Optionally, a lubricating oil filling port and a lubricating oil discharge port communicating with the first sealing cavity and / or the fourth sealing cavity are formed on the sealing seat.

[0025] By adopting the above technical solution, the lubricating oil in the first sealing chamber and / or the fourth sealing chamber can be conveniently supplemented or replaced. This design makes the maintenance operation simpler and more efficient, and the lubricating oil management can be completed without disassembling the sealing structure, which effectively ensures the good lubrication state of the sealing components, thereby improving the overall sealing performance and the reliability of equipment operation.

[0026] Optionally, the force-adding assembly further comprises a push ring, which is slidably sleeved outside the shaft sleeve and has one end abutting against an end of the elastic member away from the moving ring, and the other end slidably abutting against a wedge surface of the centrifugal push block.

[0027] By adopting the above technical solution, the setting of the push ring effectively avoids the centrifugal push block from directly contacting the elastic member, thereby preventing the elastic member from prematurely wearing out due to friction, and significantly improving the service life and working reliability of the entire sealing structure. At the same time, the existence of the push ring makes the thrust applied by the centrifugal push block to the elastic member more evenly distributed, further improving the stability of the abutment between the dynamic ring and the static ring, and enhancing the sealing effect.

[0028] Optionally, a first sealing ring is further provided between the sealing seat and the rotating shaft, the first sealing ring is located on the side of the static ring away from the dynamic ring, and the first sealing ring is a corrugated sealing ring.

[0029] By adopting the above technical solution, the first sealing ring can form an effective pre-sealing barrier on the side of the static ring away from the dynamic ring; on the one hand, the first sealing ring can pre-block part of the sealed medium, reduce the pressure load on the subsequent abutment between the dynamic ring and the static ring, thereby reducing the direct impact of the sealed medium on the abutment part of the dynamic ring and the static ring; on the other hand, the first sealing ring can also play a filtering function, effectively intercepting impurities from entering the precise matching area between the dynamic ring and the static ring, avoiding wear or sealing failure caused by the intrusion of impurities, and further improving the working stability and life of the entire sealing structure.

[0030] Optionally, a second sealing ring is provided between the moving ring and the rotating shaft.

[0031] By adopting the above technical solution, the second sealing ring can ensure the sealing performance between the dynamic ring and the rotating shaft, effectively prevent the sealed medium from leaking from the gap between the dynamic ring and the rotating shaft, and improve the reliability and stability of the entire sealing structure.

[0032] In summary, this application includes the following beneficial technical effects:

[0033] 1. The improved sealing structure can effectively improve the sealing performance and sealing stability under high-speed rotation conditions, and reduce the influence of centrifugal force on its sealing performance. Specifically, the force-increasing component utilizes the centrifugal force generated by the rotation of the rotating shaft to increase the abutting force of the dynamic ring against the static ring, making the contact between the two closer. At the same time, it can also pressurize the first sealing cavity, so that after the pressure on the lip side of the first lip-shaped sealing ring increases, the lip edge of the first lip-shaped sealing ring abuts more closely against the outer wall of the rotating shaft. Moreover, the higher the rotation speed of the rotating shaft, the closer the dynamic ring and the static ring abut, and the closer the first lip-shaped sealing ring and the outer wall of the rotating shaft. In addition, the double sealing of the first lip-shaped sealing ring and the mechanical seal component combines the advantages of the two sealing methods, enabling the sealing structure to have good sealing effects both in low-speed static and high-speed dynamic states, greatly expanding the application range of the sealing structure, and enabling it to perform excellently under a wider range of working conditions.

[0034] 2. The improved sealing structure can effectively enhance the abutting force between the dynamic ring and the static ring under high-speed rotation conditions, and at the same time further improve the abutting force between the first lip-shaped sealing ring and the surface of the rotating shaft by pressurizing the first sealing cavity. Specifically, the centrifugal push block in the force-increasing component slides along the chute under the action of the centrifugal force generated when the rotating shaft rotates, pushing the elastic member to move towards the dynamic ring, increasing the pressing force of the dynamic ring against the static ring, thereby enhancing the sealing effect. And the centrifugal push block forces the elastic membrane to bulge, increasing the pressure in the first sealing cavity, and increasing the abutting force between the lip edge of the first lip-shaped sealing ring and the surface of the rotating shaft, further preventing the leakage of the sealing medium. This design not only improves the overall stability and reliability of the sealing device, but also significantly extends the service life of the equipment and reduces the maintenance cost.

[0035] 3. During the rotation of the rotating shaft, the centrifugal push block pushes the elastic member to move towards the dynamic ring under the action of centrifugal force, and at the same time drives the elastic membrane to bulge. After the elastic membrane bulges, it compresses the first sealing cavity, applying an additional pressure to the lip side of the first lip-shaped sealing ring, enhancing the degree of fit between the first lip-shaped sealing ring and the outer wall of the shaft sleeve, and effectively improving the sealing performance at this position. On the other hand, when the elastic membrane bulges, it will also form a negative pressure in the communication cavity connected to it, and then transmit the negative pressure to the second sealing cavity through the channel opened on the shaft sleeve. This design not only realizes the pressure balance on both sides of the elastic membrane, avoiding structural deformation or failure caused by excessive unilateral force, but also further strengthens the abutting force between the first lip-shaped sealing ring and the second lip-shaped sealing ring and the outer wall of the shaft sleeve through the negative pressure effect, thereby greatly improving the stability and reliability of the entire sealing system and significantly reducing the risk of medium leakage under high-speed operation conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 is the overall structural schematic diagram of the embodiment of the present application.

[0037] Figure 2 isFigure 1 Partial enlarged view of part A.

[0038] Figure 3 It is Figure 1 Cross-sectional view taken along line B-B in the figure.

[0039] Explanation of reference numerals: 100, sealing seat; 110, mounting hole; 120, lubricating oil filling port; 130, lubricating oil discharge port; 200, rotating shaft; 300, bearing; 1, mechanical seal assembly; 11, stationary ring; 12, rotating ring; 13, elastic member; 2, first lip seal; 3, force application assembly; 31, mounting ring; 311, sliding groove; 32, centrifugal push block; 33, elastic membrane; 34, push ring; 4, shaft sleeve; 41, communication cavity; 5, second lip seal; 6, first seal ring; 7, second seal ring; 8, spacer ring; 101, first sealing cavity; 102, second sealing cavity; 103, third sealing cavity; 104, fourth sealing cavity. Detailed implementation manners

[0040] The following Figure 1 - Figure 3 further elaborates on this application in detail.

[0041] The embodiment of this application discloses an improved sealing structure.

[0042] Referring to Figure 1 , in this embodiment, the sealing structure includes a sealing seat 100, a rotating shaft 200, a mechanical seal assembly 1, a first lip seal 2, a force application assembly 3, a shaft sleeve 4, and a second lip seal 5. Specifically, the sealing seat 100 is fixedly installed on a sealed container (not shown in the figure). The sealing seat 100 is made of a metal material with high temperature resistance and wear resistance, such as stainless steel or nickel-based alloy. The sealing seat 100 is provided with a mounting hole 110 communicating with the outside and the inside of the sealed container. The rotating shaft 200 is a rotating member to be sealed, and the rotating shaft 200 is inserted into the mounting hole 110 and rotatably connected to the sealing seat 100 through a bearing 300. The shaft sleeve 4 is fixedly sleeved outside the rotating shaft 200, and the inner wall of the shaft sleeve 4 is in sealing contact with the outer wall of the rotating shaft 200. The material of the shaft sleeve 4 can be selected from metal materials with high temperature resistance and wear resistance, such as stainless steel or nickel-based alloy, to ensure its stability and durability in high temperature and high pressure environments. In other embodiments, the sealing seat 100 can be a part of the structure of the sealed container.

[0043] Referring to Figure 1 and Figure 2In this embodiment, the mechanical seal assembly 1 includes a stationary ring 11, a dynamic ring 12 and an elastic member 13; the stationary ring 11 is usually made of silicon carbide or ceramic material and has good chemical stability and thermal stability; the stationary ring 11 is located in the mounting hole 110, and the stationary ring 11 is sleeved on the outside of the rotating shaft 200 and there is a certain gap between the stationary ring 11 and the outer wall of the rotating shaft 200, and the outer ring wall of the stationary ring 11 is sealed against the hole wall of the mounting hole 110 to be fixed on the sealing seat 100, and an O-ring for sealing is provided between the stationary ring 11 and the sealing seat 100.

[0044] The moving ring 12 can be made of cemented carbide or stainless steel to enhance its wear resistance; the moving ring 12 is also located in the mounting hole 110 and is sealingly and slidably arranged on the rotating shaft 200. The sliding direction of the moving ring 12 is parallel to the rotation axis of the rotating shaft 200. When the rotating shaft 200 rotates, the moving ring 12 rotates together with the rotating shaft 200; the stationary ring 11 is closer to the sealed medium than the moving ring 12, and the side of the moving ring 12 close to the sealed medium is rotatably abutted with the side of the stationary ring 11 close to the moving ring 12, and the direction of the centrifugal force of the rotation of the rotating shaft 200 is the same as the leakage direction when the sealed medium leaks from between the moving ring 12 and the stationary ring 11.

[0045] The elastic member 13 is a spring, generally a disc spring or a bellows spring, and the specifications and models can be flexibly adjusted according to actual needs; the elastic member 13 is sleeved on the outside of the rotating shaft 200 to provide a certain abutment force when the dynamic ring 12 rotates to abut against the static ring 11, so as to ensure that the two maintain a good sealing effect. In other embodiments, the material of the static ring 11 can also be a graphite composite material; the material of the dynamic ring 12 can also be silicon carbide, tungsten carbide and titanium alloy; the elastic member 13 can also be a tension spring.

[0046] Preferably, a first sealing ring 6 is further provided between the sealing seat 100 and the rotating shaft 200. The first sealing ring 6 is located on the side of the static ring 11 away from the dynamic ring 12, and the first sealing ring 6 is a corrugated sealing ring; the outer wall of the first sealing ring 6 is sealed against the hole wall of the mounting hole 110, and the inner wall is sealed against the outer wall of the sleeve 4; in this way, on the one hand, part of the sealed medium can be blocked in advance, thereby reducing the pressure load on the subsequent abutment between the dynamic ring 12 and the static ring 11; on the other hand, impurities can be effectively intercepted from entering the precise matching area between the dynamic ring 12 and the static ring 11.

[0047] Preferably, a second sealing ring 7 is provided between the moving ring 12 and the rotating shaft 200. The second sealing ring 7 can be an O-ring. The outer wall of the second sealing ring 7 is sealed against the inner ring wall of the moving ring 12, and the inner wall is sealed against the outer wall of the sleeve 4. This ensures the sealing performance between the moving ring 12 and the sleeve 4 when the moving ring 12 slides.

[0048] Reference Figure 1 and Figure 2, in this embodiment, the first lip seal 2 can be made of rubber materials such as nitrile butadiene rubber (NBR) or fluororubber (FKM), both of which have excellent oil resistance and heat resistance; the cross-section of the first lip seal 2 can be one of Y-shaped, U-shaped, and V-shaped; the first lip seal 2 is arranged on the side of the mechanical seal assembly 1 away from the sealed medium and the lip of the first lip seal 2 faces the mechanical seal assembly 1; the first lip seal 2 is located in the mounting hole 110 and sleeved on the outer side of the rotating shaft 200, and the outer wall of the first lip seal 2 is in sealing contact with the hole wall of the mounting hole 110 to be fixed on the seal seat 100; the lip edge of the first lip seal 2 is in sliding contact with the outer wall of the sleeve 4; a first seal cavity 101 is formed among the first lip seal 2, the mechanical seal assembly 1, the seal seat 100, and the sleeve 4, and a communication cavity 41 communicating with the first seal cavity 101 is formed on the sleeve 4. In other embodiments, the first lip seal 2 can also be selected as hydrogenated nitrile butadiene rubber (HNBR).

[0049] Refer to Figure 1 and Figure 3 , in this embodiment, the force application assembly 3 is arranged on the side of the mechanical assembly on the rotating shaft 200 away from the sealed medium. The force application assembly 3 rotates together with the rotating shaft 200, and the force application assembly 3 can use the centrifugal force generated by rotation to increase the abutting force of the dynamic ring 12 against the static ring 11 and pressurize the first seal cavity 101.

[0050] The force application assembly 3 includes a mounting ring 31, a plurality of centrifugal push blocks 32, an elastic membrane 33, and a push ring 34. The mounting ring 31 is sleeved on the outer sides of the rotating shaft 200 and the sleeve 4, and the inner wall of the mounting ring 31 is in sealing contact with the outer wall of the sleeve 4 to be fixed on the sleeve 4. When the rotating shaft 200 rotates, the mounting ring 31 rotates together with the rotating shaft 200; a plurality of sliding grooves 311 are circumferentially and equally spaced along the rotation axis of the rotating shaft 200 on the mounting ring 31, and the extending direction of the sliding grooves 311 is parallel to the centrifugal force direction of the rotating shaft 200.

[0051] Refer to Figure 1 and Figure 2 , the centrifugal push block 32 is specifically a metal block with a wedge-shaped appearance. The specific material can be selected as alloy steel or high-speed steel, which has high density and good wear resistance and impact resistance; a plurality of centrifugal push blocks 32 are arranged in a one-to-one correspondence in a plurality of sliding grooves 311, and the narrow wedge-shaped end of the centrifugal push block 32 faces away from the rotating shaft 200 and the wedge-shaped surface faces the side of the mechanical seal assembly 1.

[0052] The push ring 34 can also be made of alloy steel or high-speed steel, and has good wear resistance and impact resistance; the push ring 34 sliding sleeve is arranged on the outer side of the sleeve 4 and the sliding direction of the push ring 34 is parallel to the rotation axis of the sleeve 4, one end of the elastic member 13 abuts on the push ring 34, and the other end abuts on the end of the dynamic ring 12 away from the static ring 11, and the end of the push ring 34 away from the elastic member 13 slides and abuts on the wedge surface of the centrifugal push block 32.

[0053] The elastic membrane 33 is specifically an elastic film made of rubber material. The elastic membrane 33 is arranged in the first sealing cavity 101, and the edge of the elastic membrane 33 is sealed and connected to the surface of the sleeve 4 to separate the first sealing cavity 101 and the connecting cavity 41. The middle elastic part of the elastic membrane 33 is connected to one end of the centrifugal push block 32 close to the sleeve 4.

[0054] When the rotating shaft 200 rotates, the centrifugal push block 32 can slide along the slide groove 311 in the direction away from the rotating shaft 200 under the action of centrifugal force, and the centrifugal push block 32 pushes the push ring 34 to approach the dynamic ring 12 and pulls the elastic film 33 to bulge toward the side of the first sealing chamber 101; when the push ring 34 approaches the dynamic ring 12, it pushes the elastic member 13 to compress in the direction of approaching the dynamic ring 12, thereby increasing the contact force of the dynamic ring 12 on the static ring 11; when the elastic film 33 bulges into the first sealing chamber 101, it compresses the first sealing chamber 101; thereby increasing the pressure on the lip side of the first lip-shaped sealing ring 2, so that the lip edge of the first lip-shaped sealing ring 2 abuts against the outer wall of the sleeve 4 more closely, thereby enhancing the sealing performance; and the faster the rotation speed of the rotating shaft 200, the greater the centrifugal force of the centrifugal push block 32, even if the contact force of the dynamic ring 12 on the static ring 11 is greater, the contact force of the lip edge of the first lip-shaped sealing ring 2 against the outer wall of the sleeve 4 is also greater.

[0055] Preferably, the first sealing chamber 101 is filled with lubricating oil, which can absorb the friction heat between the dynamic ring 12 and the static ring 11 and the friction heat between the first lip seal ring 2 and the sleeve 4 and provide lubrication for them during friction; the volume expansion of the lubricating oil after being heated can increase the pressure in the first sealing chamber 101, further making the lip edge of the first lip seal ring 2 more tightly abut against the outer wall of the sleeve 4, thereby enhancing the sealing performance.

[0056] Reference Figure 1 and Figure 2, in this embodiment, the sealing structure further includes a plurality of second lip seals 5 sleeved on the outer side of the bushing 4 in a staggered manner. The second lip seals 5 can be made of rubber materials such as nitrile rubber (NBR) or fluororubber (FKM), both of which have excellent oil resistance and temperature resistance; the cross-section of the second lip seal 5 can be one of Y-shaped, U-shaped, and V-shaped; a plurality of second lip seals 5 are all arranged in the mounting hole 110 and sleeved on the outer side of the rotating shaft 200, and a plurality of second lip seals 5 are all located on the side of the first lip seal 2 away from the first sealing cavity 101; the outer walls of a plurality of second lip seals 5 are all in sealing contact with the wall of the mounting hole 110 to be fixed on the sealing seat 100; the lips of a plurality of second lip seals 5 are all in sliding contact with the outer wall of the bushing 4; the lip opening of the second lip seal 5 adjacent to the first lip seal 2 faces away from the first lip seal 2, so that a second sealing cavity 102 communicating with the communication cavity 41 is formed between the first lip seal 2 and the second lip seal 5. In other embodiments, the second lip seal 5 can also be selected as hydrogenated nitrile rubber (HNBR).

[0057] When the elastic membrane 33 bulges towards the first sealing cavity 101, a negative pressure can be formed in the communication cavity 41 and the second sealing cavity 102, so that a negative pressure is formed on the side of the first lip seal 2 away from the lip opening, further increasing the contact force between the lip of the first lip seal 2 and the surface of the bushing 4.

[0058] Refer to Figure 1 and Figure 2 , in this embodiment, a spacer ring 8 for spacing adjacent second lip seals 5 is provided in the mounting hole 110; the outer ring wall of the spacer ring 8 is in contact with and fixed to the wall of the mounting hole 110, and there is a certain gap between the inner ring wall and the bushing 4; when the lip openings of adjacent second lip seals 5 face away from each other, a third sealing cavity 103 is formed among the two second lip seals 5, the bushing 4, and the inner ring wall of the spacer ring 8, and the third sealing cavity 103 communicates with the communication cavity 41; when a negative pressure is formed in the communication cavity 41, a negative pressure will also be generated in the third sealing cavity 103 communicating therewith, thus increasing the contact force between the lip of the second lip seal 5 and the outer wall of the bushing 4 and enhancing the sealing performance.

[0059] When the lip openings of adjacent second lip seals 5 face each other, a fourth sealing cavity 104 is formed among the two second lip seals 5, the bushing 4, and the inner ring wall of the spacer ring 8. Lubricating oil is filled in the fourth sealing cavity 104. The lubricating oil can absorb the frictional heat between the second lip seal 5 and the bushing 4 and provide lubrication during their friction; when the lubricating oil is heated, its volume expands, which can increase the pressure in the fourth sealing cavity 104, further making the lip of the second lip seal 5 more closely contact the outer wall of the bushing 4 and enhancing the sealing performance.

[0060] Preferably, the sealing seat 100 is provided with a lubricating oil filling port 120 and a lubricating oil discharge port 130 connected to the first sealing cavity 101 and / or the fourth sealing cavity 104; this allows the lubricating oil in the first sealing cavity 101 and / or the fourth sealing cavity 104 to be easily replenished or replaced.

[0061] The implementation principle of an improved sealing structure in an embodiment of the present application is as follows: the force-adding component 3 utilizes the centrifugal force generated by the rotation of the rotating shaft 200 to increase the abutment force of the dynamic ring 12 on the static ring 11, making the contact between the two closer, and at the same time it can also increase the pressure in the first sealing cavity 101, so that after the pressure on one side of the lip of the first lip-shaped sealing ring 2 is increased, the lip edge of the first lip-shaped sealing ring 2 abuts more closely against the outer wall of the rotating shaft 200. Specifically, when the rotating shaft 200 rotates, the centrifugal push block 32 can slide along the slide groove 311 in the direction away from the rotating shaft 200 under the action of centrifugal force, and the centrifugal push block 32 pushes the push ring 34 to approach the dynamic ring 12 and pulls the elastic membrane 33 to bulge toward the side of the first sealing cavity 101; when the push ring 34 approaches the dynamic ring 12, it pushes the elastic member 13 to be compressed in the direction of approaching the dynamic ring 12, thereby increasing the abutment force of the dynamic ring 12 on the static ring 11; when the elastic membrane 33 bulges into the first sealing cavity 101, it compresses the first sealing cavity 101; thereby increasing the pressure on the lip side of the first lip-shaped sealing ring 2, so that the lip edge of the first lip-shaped sealing ring 2 abuts against the outer wall of the sleeve 4 more closely, thereby enhancing the sealing performance; and the higher the rotation speed of the rotating shaft 200, the lower the rotation speed of the rotating shaft 200. The faster the centrifugal push block 32, the greater the centrifugal force, even if the abutting force of the dynamic ring 12 on the static ring 11 is greater, the abutting force between the lip edge of the first lip seal ring 2 and the outer wall of the sleeve 4 is also greater; and when the elastic membrane 33 bulges toward the side of the first sealing cavity 101, it can form a negative pressure in the connecting cavity 41 and the second sealing cavity 102, so that a negative pressure is formed on the side of the first lip seal ring 2 away from the lip, further increasing the abutting force between the lip edge of the first lip seal ring 2 and the surface of the sleeve 4; in addition, the double sealing of the first lip seal ring 2 and the mechanical seal assembly 1 combines the advantages of two sealing methods, so that the sealing structure can have a good sealing effect in both low-speed static and high-speed dynamic conditions, greatly expanding the application range of the sealing structure.

[0062] The above are all preferred embodiments of the present application, and the protection scope of the present application is not limited thereto. Therefore, any equivalent changes made according to the structure, shape, and principle of the present application should be included in the protection scope of the present application.

Claims

1. An improved sealing structure, characterized in that: include: Sealing seat (100); A rotating shaft (200), the rotating shaft (200) being rotatably connected to the sealing seat (100); A mechanical seal assembly (1), the mechanical seal assembly (1) comprising a stationary ring (11), a dynamic ring (12) and an elastic member (13), the stationary ring (11) being sealingly connected to a sealing seat (100); the dynamic ring (12) being sealingly slidably arranged on a rotating shaft (200), the sliding direction of the dynamic ring (12) being parallel to the rotation axis of the rotating shaft (200); the side of the dynamic ring (12) close to the sealed medium being in rotational contact with the side of the stationary ring (11), and the centrifugal force direction of the rotating shaft (200) being in rotation with the sealed medium from the dynamic ring (12) and the stationary ring (11) ) when leakage occurs between the two rings; the elastic member (13) is used to provide a certain abutment force when the dynamic ring (12) rotates to abut against the static ring (11); a first lip seal ring (2), the outer wall of the first lip seal ring (2) is sealingly connected to the sealing seat (100), the first lip seal ring (2) is located on a side of the mechanical seal assembly (1) away from the sealed medium, and the lip of the first lip seal ring (2) faces the mechanical seal assembly (1), and a first sealing cavity (101) is formed between the first lip seal ring (2) and the mechanical seal assembly (1); A force-adding component (3), the force-adding component (3) being arranged on the rotating shaft (200) and rotating together with the rotating shaft (200), the force-adding component (3) being capable of increasing the contact force of the dynamic ring (12) on the static ring (11) and increasing the pressure in the first sealing chamber (101) in direct proportion to the centrifugal force generated by the rotation; A shaft sleeve (4), wherein the shaft sleeve (4) is sleeved on the outside of the rotating shaft (200) and the inner wall of the shaft sleeve (4) is in sealing contact with the outer wall of the rotating shaft (200); the lip edge of the first lip seal ring (2) is in sliding contact with the outer surface of the shaft sleeve (4); The force-applying component (3) comprises a mounting ring (31), a plurality of centrifugal push blocks (32) and an elastic membrane (33); the mounting ring (31) is sleeved on the shaft sleeve (4) and rotates together with the rotating shaft (200); the mounting ring (31) is provided with a plurality of slide grooves (311) along the circumferential direction of the rotating axis of the rotating shaft (200); the plurality of centrifugal push blocks (32) are arranged in a one-to-one correspondence in the plurality of slide grooves (311); the centrifugal push blocks (32) are wedge-shaped and the narrow ends thereof are away from the rotating shaft (200); one end of the elastic member (13) abuts against an end of the moving ring (12) away from the stationary ring (11); the force-applying component (3) further comprises a push ring (34); the push ring (34) is slidably sleeved One end of the push ring (34) is outside the shaft sleeve (4) and abuts against one end of the elastic member (13) facing away from the moving ring (12), and the other end is in sliding abutment with the wedge-shaped surface of the centrifugal push block (32); the elastic membrane (33) is arranged in the first sealing cavity (101), the edge of the elastic membrane (33) is sealingly connected to the surface of the shaft sleeve (4), and the elastic membrane (33) is connected to the centrifugal push block (32); when the rotating shaft (200) rotates, the centrifugal push block (32) can slide along the slide groove (311) in a direction away from the rotating shaft (200) under the action of centrifugal force to push the elastic member (13) to move towards the moving ring (12) and make the elastic membrane (33) bulge and compress the first sealing cavity (101).

2. An improved sealing structure according to claim 1, characterized in that: It also comprises a plurality of second lip seal rings (5) which are arranged on the outside of the shaft sleeve (4) in an alternating manner, the outer walls of the plurality of second lip seal rings (5) being sealingly connected to the sealing seat (100), and the lip edges of the plurality of second lip seal rings (5) all slidably abut against the outer wall of the shaft sleeve (4).

3. An improved sealing structure according to claim 2, characterized in that: The plurality of second lip-shaped sealing rings (5) are all located on a side of the first lip-shaped sealing ring (2) facing away from the first sealing cavity (101), and the lips of the second lip-shaped sealing rings (5) adjacent to the first lip-shaped sealing ring (2) are oriented away from the first lip-shaped sealing ring (2); a second sealing cavity (102) is formed between the first lip-shaped sealing ring (2) and the second lip-shaped sealing ring (5); a connecting cavity (41) is provided on the shaft sleeve (4) and connects the second sealing cavity (102) and the side of the elastic membrane (33) facing away from the first sealing cavity (101); and when the elastic membrane (33) bulges, negative pressure can be formed in the connecting cavity (41).

4. An improved sealing structure according to claim 3, characterized in that: A third sealing cavity (103) is formed when the lips of adjacent second lip-shaped sealing rings (5) are facing each other, and a fourth sealing cavity (104) is formed when the lips are facing each other; the third sealing cavity (103) is connected to the connecting cavity (41); and lubricating oil is contained in the first sealing cavity (101) and the fourth sealing cavity (104).

5. An improved sealing structure according to claim 4, characterized in that: The sealing seat (100) is provided with a lubricating oil filling port (120) and a lubricating oil discharge port (130) which are connected to the first sealing cavity (101) and / or the fourth sealing cavity (104).

6. An improved sealing structure according to claim 1, characterized in that: A first sealing ring (6) is also provided between the sealing seat (100) and the rotating shaft (200), the first sealing ring (6) being located on a side of the stationary ring (11) away from the dynamic ring (12), and the first sealing ring (6) being a corrugated sealing ring.

7. An improved sealing structure according to claim 1, characterized in that: A second sealing ring (7) is provided between the moving ring (12) and the rotating shaft (200).

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