Improved sealing structure

Abstract

The invention relates to the technical field of mechanical sealing, in particular to an improved sealing structure which comprises a sealing seat, a rotating shaft, a mechanical sealing assembly, a first lip-shaped sealing ring and a stress application assembly. Wherein the rotating shaft is rotationally connected with the sealing seat; the mechanical sealing assembly comprises a static ring, a movable ring and an elastic piece. The mechanical sealing assembly comprises a static ring, a movable ring and an elastic piece. The static ring is connected to the sealing seat in a sealed mode. The side, close to a sealed medium, of the movable ring is rotationally connected with one side of the static ring in an abutting mode. The outer wall of the first lip-shaped sealing ring is connected to the sealing seat in a sealed mode, the lip edge of the first lip-shaped sealing ring abuts against the outer wall of the rotating shaft in a sliding mode, and a first sealing cavity is formed between the first lip-shaped sealing ring and the mechanical sealing assembly. The force applying assembly can increase the abutting force of the movable ring to the static ring and pressurize the interior of the first sealing cavity in a direct proportion by means of centrifugal force generated by rotation. The sealing device has the effects that the sealing effect of the sealing device is improved, and the influence of centrifugal force on the sealing performance is reduced.

Description

Technical Field

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

[0002] The final polymerization kettle is an important equipment for the synthesis of polymer materials. It is widely used in the production process of polymers such as polyester and polyurethane. This type of equipment plays a key role in industrial production because it can effectively control the reaction conditions and ensure product quality and production safety. However, due to the complex and changeable internal environment of the final polymerization kettle, it is often affected by high temperature, high pressure and corrosive media, which puts extremely high demands on the reliability and safety of the equipment, especially in terms of the sealing performance of the rotating connection of the stirring shaft; good sealing can not only ensure the smooth progress of the process, 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, in order to meet these challenges, a sealing structure is used in combination with a lip seal ring and an external mechanical seal at the rotating connection of the stirring shaft. The lip seal ring is in close contact with the shaft surface through its flexible lip portion to achieve preliminary static or low-speed dynamic sealing; while the external mechanical seal is to install the static ring on the outside of the sealing gland, and use the precise fit between the dynamic ring and the static ring to maintain the dynamic sealing effect under high pressure, high temperature and high speed through the action of the spring.

[0004] Although the above technologies have met the basic sealing requirements to a certain extent, there are still obvious shortcomings. Especially in the case of high-speed rotation, the lip of the lip seal ring will be subjected to strong centrifugal force, causing the lip to stretch outward, reducing the contact pressure with the shaft, thereby reducing the sealing effect; the external mechanical seal will also have the sealing medium leaking from the abutment gap between the dynamic ring and the static 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, the present application provides an improved sealing structure.

[0006] An improved sealing structure provided in this application adopts the following technical solution: An improved sealing structure, comprising: Sealing seat; A rotating shaft, the rotating shaft being rotatably connected to the sealing seat; 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; 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; 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.

[0007] 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.

[0008] 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.

[0009] 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.

[0010] Optionally, the force-adding assembly includes a mounting ring, a plurality of centrifugal push blocks and an elastic membrane; the mounting ring is sleeved on the shaft sleeve and rotates together with the rotating shaft, the mounting ring is provided with a plurality of slide grooves along the circumferential direction of the rotating axis of the rotating shaft, and the plurality of centrifugal push blocks are arranged in the plurality of slide grooves in a one-to-one correspondence; the centrifugal push blocks are wedge-shaped and the narrow end faces away from the rotating shaft, one end of the elastic member abuts against the end of the moving ring away from the static ring, and the other end abuts against the wedge-shaped surface of the centrifugal push block; the elastic membrane is arranged in the first sealing cavity, the edge of the elastic membrane is sealed and connected to the surface of the shaft sleeve and the elastic membrane is connected to the centrifugal push block; when the rotating shaft rotates, the centrifugal push block can slide along the slide groove in the direction away from the rotating shaft under the action of centrifugal force to push the elastic member to move toward the moving ring and cause the elastic membrane to bulge and compress the first sealing cavity.

[0011] By adopting the above technical scheme, the improved sealing structure can effectively enhance the contact force between the dynamic ring and the static ring under high-speed rotation conditions, and at the same time further enhance the contact force between the first lip seal ring and the surface of the rotating shaft by increasing the pressure in the first sealing chamber; specifically, the centrifugal push block in the force-adding assembly slides along the slide groove under the action of the centrifugal force generated when the rotating shaft rotates, pushing the elastic member to move toward the dynamic ring, increasing the pressure of the dynamic ring on the static ring, thereby enhancing the sealing effect; and the centrifugal push block forces the elastic membrane to bulge, thereby increasing the pressure in the first sealing chamber, and increasing the contact force between the lip edge of the first lip seal ring and the surface of the rotating shaft, further preventing 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 maintenance costs.

[0012] Optionally, it also includes a plurality of second lip seals which are alternately sleeved on the outside of the sleeve, the outer walls of the plurality of second lip seals are sealingly connected to the sealing seat, and the lip edges of the plurality of second lip seals all slide against the outer wall of the sleeve.

[0013] By adopting the above technical solution, the sealing structure further enhances the overall sealing effect by staggeredly sleeved a plurality of second lip seals on the outer side of the sleeve; the outer wall of each second lip seal is tightly connected to the sealing seat, and its lip edge slides against the outer wall of the sleeve to form multiple lines of defense; this design not only improves the reliability of a single sealing point, but also effectively prevents overall leakage problems caused by failure of a single seal; in addition, the design of multiple seals ensures that even if one seal is damaged, other seals can continue to function, greatly improving the stability and safety of the system.

[0014] Optionally, the plurality of second lip-shaped sealing rings are all located on the side of the first lip-shaped sealing ring away from the first sealing cavity, and the lip of the second lip-shaped sealing ring adjacent to the first lip-shaped sealing ring is oriented away from the first lip-shaped sealing ring; a second sealing cavity is formed between the first lip-shaped sealing ring and the second lip-shaped sealing ring; a connecting cavity connecting the second sealing cavity and the side of the elastic membrane away from the first sealing cavity is provided on the sleeve; and negative pressure can be formed in the connecting cavity when the elastic membrane bulges.

[0015] By adopting the above technical scheme, during the rotation of the shaft, the centrifugal push block pushes the elastic part to move 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, and applies additional pressure on the lip side of the first lip sealing ring, thereby enhancing the fit between the first lip sealing ring and the outer wall of the sleeve, and effectively improving the sealing performance of this position; on the other hand, when the elastic membrane bulges, it will also form a negative pressure in the connecting cavity connected to it, and then transmit the negative pressure to the second sealing cavity through the channel opened on the sleeve; this design not only achieves the balance of pressure on both sides of the elastic membrane, avoiding structural deformation or failure due to excessive force on one side, but also further strengthens the contact force between the first lip sealing ring and the second lip sealing ring and the outer wall of the 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.

[0016] Optionally, a third sealing cavity is formed between adjacent second lip sealing rings when the lips are back to back, and a fourth sealing cavity is formed when the lips are facing each other; the third sealing cavity is connected to the connecting cavity; and the first sealing cavity and the fourth sealing cavity are filled with lubricating oil.

[0017] By adopting the above technical scheme, when negative pressure is formed in the connecting cavity, the third sealing cavity connected thereto will also generate negative pressure; this negative pressure effect makes the side of the second lip sealing ring away from the lip tightly adsorbed on the outer wall of the sleeve, thereby enhancing the sealing performance; the lubricating oil in the first sealing cavity and the fourth sealing cavity expands in volume after frictional heat generation, which can apply additional pressure to the first sealing cavity and the fourth sealing cavity respectively, and further make the lip edges of the first lip sealing ring and the second lip sealing ring more closely abut the outer wall of the sleeve, thereby enhancing the sealing performance; in addition, the presence of the lubricating oil effectively reduces the friction resistance between the first lip sealing ring, the second lip sealing ring and the outer wall of the sleeve, thereby improving the overall operation smoothness and durability.

[0018] Optionally, the sealing seat is provided with a lubricating oil filling port and a lubricating oil discharge port connected to the first sealing cavity and / or the fourth sealing cavity.

[0019] 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.

[0020] 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.

[0021] 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.

[0022] 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.

[0023] 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.

[0024] Optionally, a second sealing ring is provided between the moving ring and the rotating shaft.

[0025] 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.

[0026] In summary, this application includes the following beneficial technical effects: 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-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 is increased, 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 at 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; 2. The improved sealing structure can effectively enhance the contact force between the dynamic ring and the static ring under high-speed rotation conditions, and at the same time further enhance the contact force between the first lip seal ring and the surface of the rotating shaft by increasing the pressure in the first sealing chamber; specifically, the centrifugal push block in the force-adding assembly slides along the slide groove under the centrifugal force generated when the rotating shaft rotates, pushing the elastic member to move toward the dynamic ring, increasing the pressure of the dynamic ring on the static ring, thereby enhancing the sealing effect; and the centrifugal push block forces the elastic membrane to bulge, thereby increasing the pressure in the first sealing chamber, increasing the contact force between the lip edge of the first lip seal ring and the surface of the rotating shaft, and 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 maintenance costs; 3. During the rotation of the shaft, the centrifugal push block pushes the elastic part 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, and applies additional pressure on the lip side of the first lip sealing ring, thereby enhancing the fit between the first lip sealing ring and the outer wall of the sleeve, and effectively improving the sealing performance of this position; on the other hand, when the elastic membrane bulges, it will also form a negative pressure in the connecting cavity connected to it, and then transmit the negative pressure to the second sealing cavity through the channel opened on the sleeve; this design not only achieves the balance of pressure on both sides of the elastic membrane, avoiding structural deformation or failure due to excessive force on one side, but also further strengthens the contact force between the first lip sealing ring and the second lip sealing ring and the outer wall of the sleeve through the action of negative pressure, 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

[0027] Figure 1 It is a schematic diagram of the overall structure of an embodiment of the present application.

[0028] Figure 2 yes Figure 1 A partial enlarged view of part A.

[0029] Figure 3 is along Figure 1 Sectional view along line BB.

[0030] Explanation of the 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, moving ring; 13, elastic member; 2, first lip seal ring; 3, force assembly; 31, mounting ring; 311, slide groove; 32, centrifugal push block; 33, elastic membrane; 34, push ring; 4, bushing; 41, connecting chamber; 5, second lip seal ring; 6, first seal ring; 7, second seal ring; 8, spacer ring; 101, first sealing chamber; 102, second sealing chamber; 103, third sealing chamber; 104, fourth sealing chamber. DETAILED DESCRIPTION

[0031] The following combination Figure 1 - Figure 3 This application is described in further detail.

[0032] The embodiment of the present application discloses an improved sealing structure.

[0033] Reference Figure 1 In this embodiment, the sealing structure includes a sealing seat 100, a rotating shaft 200, a mechanical sealing assembly 1, a first lip seal ring 2, a force assembly 3, a sleeve 4 and a second lip seal ring 5. Specifically, the sealing seat 100 is fixedly mounted on the sealed container (not shown in the figure), and the sealing seat 100 is made of a high temperature resistant and wear-resistant metal material, such as stainless steel or nickel-based alloy; the sealing seat 100 is provided with a mounting hole 110 that connects the outside and the inside of the sealed container; the rotating shaft 200 is a sealed rotating part, and the rotating shaft 200 is inserted into the mounting hole 110 and is rotatably connected to the sealing seat 100 through a bearing 300; the sleeve 4 is fixedly sleeved on the outside of the rotating shaft 200, and the inner wall of the sleeve 4 is sealed against the outer wall of the rotating shaft 200; the material of the sleeve 4 can be selected from a high temperature resistant and wear-resistant metal material, such as stainless steel or nickel-based alloy, to ensure its stability and durability under high temperature and high pressure environment; in other embodiments, the sealing seat 100 can be a partial structure on the sealed container.

[0034] Reference 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.

[0035] 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.

[0036] 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.

[0037] 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.

[0038] 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.

[0039] Reference Figure 1 and Figure 2In this embodiment, the first lip seal ring 2 can be made of rubber material, such as nitrile rubber (NBR) or fluororubber (FKM), both of which have excellent oil resistance and temperature resistance; the cross section of the first lip seal ring 2 can be one of Y-type, U-type, and V-type; the first lip seal ring 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 ring 2 faces the mechanical seal assembly 1; the first lip seal ring 2 is located in the mounting hole 110 and is sleeved on the outside of the rotating shaft 200, and the outer wall of the first lip seal ring 2 is sealed against the hole wall of the mounting hole 110 to be fixed on the sealing seat 100; the lip edge of the first lip seal ring 2 slides against the outer wall of the sleeve 4; a first sealing cavity 101 is formed between the first lip seal ring 2, the mechanical seal assembly 1, the sealing seat 100 and the sleeve 4, and a connecting cavity 41 connected to the first sealing cavity 101 is opened on the sleeve 4. In other embodiments, the first lip seal ring 2 can also be made of hydrogenated nitrile rubber (HNBR).

[0040] Reference Figure 1 and Figure 3 In this embodiment, the force component 3 is arranged on the side of the mechanical component on the rotating shaft 200 away from the sealed medium. The force component 3 rotates together with the rotating shaft 200. The force component 3 can use the centrifugal force generated by the rotation to increase the abutment force of the dynamic ring 12 on the static ring 11 and increase the pressure in the first sealing chamber 101.

[0041] The force-applying 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; the mounting ring 31 is provided with a plurality of slide grooves 311 at equal intervals along the circumferential direction of the rotating axis of the rotating shaft 200, and the extending direction of the slide grooves 311 is parallel to the centrifugal force direction of the rotating shaft 200.

[0042] Reference 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 alloy steel or high-speed steel, which has high density and good wear resistance and impact resistance. Multiple centrifugal push blocks 32 are arranged in a one-to-one correspondence in multiple slide grooves 311, and the wedge-shaped narrow end of the centrifugal push block 32 is away from the rotating shaft 200 and the wedge-shaped surface is facing the side of the mechanical seal assembly 1.

[0043] 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.

[0044] 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.

[0045] 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.

[0046] 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.

[0047] Reference Figure 1 and Figure 2In this embodiment, the sealing structure further includes a plurality of second lip seals 5 which are alternately sleeved on the outer side of the shaft sleeve 4. The second lip seals 5 can be made of rubber material, such as nitrile rubber (NBR) or fluororubber (FKM). Both materials have excellent oil resistance and temperature resistance. The cross section of the second lip seal 5 can be one of Y-type, U-type and V-type. The 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. 5 are all located on the side of the first lip seal ring 2 away from the first sealing cavity 101; the outer walls of the plurality of second lip seal rings 5 ​​are all sealed against the hole wall of the mounting hole 110 to be fixed on the sealing seat 100; the lips of the plurality of second lip seal rings 5 ​​are all slidably against the outer wall of the shaft sleeve 4; the lip of the second lip seal ring 5 adjacent to the first lip seal ring 2 is oriented away from the first lip seal ring 2, so that a second sealing cavity 102 connected to the communication cavity 41 is formed between the first lip seal ring 2 and the second lip seal ring 5. In other embodiments, the second lip seal ring 5 can also be made of hydrogenated nitrile rubber (HNBR).

[0048] When the elastic membrane 33 bulges toward the first sealing cavity 101 , negative pressure can be formed in the connecting cavity 41 and the second sealing cavity 102 , so that negative pressure is formed on the side of the first lip seal ring 2 away from the lip, further increasing the contact force between the lip edge of the first lip seal ring 2 and the surface of the sleeve 4 .

[0049] Reference Figure 1 and Figure 2 In this embodiment, a spacing ring 8 for spacing adjacent second lip seals 5 is provided in the mounting hole 110; the outer ring wall of the spacing ring 8 is abutted and fixed on the hole wall of the mounting hole 110, and there is a certain gap between the inner ring wall and the shaft sleeve 4; when the lips of adjacent second lip seals 5 are back to back, a third sealing cavity 103 is formed between the two second lip seals 5, the shaft sleeve 4, and the inner ring wall of the spacing ring 8, and the third sealing cavity 103 is connected to the connecting cavity 41; when negative pressure is formed in the connecting cavity 41, the third sealing cavity 103 connected thereto will also generate negative pressure, thereby increasing the abutment force between the lip edge of the second lip seal 5 and the outer wall of the shaft sleeve 4, thereby enhancing the sealing performance.

[0050] When the lips of adjacent second lip-shaped sealing rings 5 ​​are facing each other, a fourth sealing chamber 104 is formed between the two second lip-shaped sealing rings 5, the shaft sleeve 4, and the inner ring wall of the spacer ring 8. The fourth sealing chamber 104 is filled with lubricating oil, which can absorb the friction heat between the second lip-shaped sealing ring 5 and the shaft sleeve 4 to provide lubrication for their friction; the volume expansion of the lubricating oil after being heated can increase the pressure in the fourth sealing chamber 104, further making the lip edge of the second lip-shaped sealing ring 5 more tightly abut against the outer wall of the shaft sleeve 4, thereby enhancing the sealing performance.

[0051] 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.

[0052] 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.

[0053] 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 is rotatably abutted against the side of the stationary ring (11), and the direction of the centrifugal force of the rotating shaft (200) is the same as the leakage direction of the sealed medium when it leaks from between the dynamic ring (12) and the stationary ring (11); the elastic member (13) is used to provide a certain abutment force when the dynamic ring (12) is rotatably abutted against the stationary ring (11); A first lip seal ring (2), wherein the outer wall of the first lip seal ring (2) is sealingly connected to the seal seat (100), the lip edge of the first lip seal ring (2) slidably abuts against the outer wall of the rotating shaft (200), 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 opening 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) is arranged on the rotating shaft (200) and rotates together with the rotating shaft (200), and the force-adding component (3) can increase the contact force of the dynamic ring (12) on the static ring (11) and increase the pressure in the first sealing chamber (101) in direct proportion to the centrifugal force generated by the rotation.

2. An improved sealing structure according to claim 1, characterized in that: It also comprises a shaft sleeve (4), the shaft sleeve (4) being sleeved on the outside of the rotating shaft (200) and the inner wall of the shaft sleeve (4) being in sealing contact with the outer wall of the rotating shaft (200); and the lip edge of the first lip seal ring (2) being in sliding contact with the outer surface of the shaft sleeve (4).

3. An improved sealing structure according to claim 2, characterized in that: The force-applying assembly (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 the moving ring (12) away from the static ring (111); ) at one end, and the other end abuts against 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 in a direction close to the moving ring (12) and cause the elastic membrane (33) to bulge and compress the first sealing cavity (101).

4. An improved sealing structure according to claim 3, 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).

5. An improved sealing structure according to claim 4, 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).

6. An improved sealing structure according to claim 5, 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).

7. An improved sealing structure according to claim 6, 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).

8. An improved sealing structure according to claim 2, characterized in that: The force-applying assembly (3) further comprises a push ring (34), which is slidably sleeved outside the shaft sleeve (4) and has one end abutting against an end of the elastic member (13) facing away from the movable ring (12), and the other end slidably abutting against a wedge-shaped surface of the centrifugal push block (32).

9. 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.

10. 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).

Images