Sealing device for high-linear-speed working condition

Abstract

The invention discloses a sealing device for a high-linear-speed working condition. The sealing device comprises a rotating shaft; the sealing body is arranged on the outer side of the rotating shaft in a sleeving manner; a centrifugal seal close to the medium side and a spiral seal close to the atmosphere side are arranged between the rotating shaft and the sealing body side by side. The centrifugal seal is provided with a centrifugal ring and a first sealing cavity, the centrifugal ring extends outwards in the radial direction of the rotating shaft, the first sealing cavity is formed in the sealing body and used for containing the centrifugal ring, and the centrifugal ring is rotatably located in the first sealing cavity; a U-shaped flow channel used for fluid flowing is defined between the centrifugal ring and the first sealing cavity. Spacer fluid is arranged at the spiral seal, and the spiral seal is used for conveying the spacer fluid to the centrifugal seal; in the working state, a sealing liquid ring is formed on the contact face of the sealing medium and the spacer fluid, and the sealing liquid ring is located in the U-shaped flow channel. The centrifugal seal and the spiral seal are arranged between the rotating shaft and the sealing body, so that the sealing medium can be effectively prevented from leaking; the sealing device can well adapt to the high-linear-speed working condition in the mode that centrifugal force generated by the high linear speed is used for reinforcing sealing, and the problem that sealing is difficult at the high linear speed is effectively solved.

Description

Technical Field

[0001] The invention belongs to the technical field of mechanical seals, and in particular relates to a sealing device for high linear speed working conditions. Background Art

[0002] With the development of technologies in industries such as petroleum, chemical industry, aerospace, and natural gas transportation, especially the increasingly harsh working conditions of high-end equipment, the requirements for sealing components are getting higher and higher. At present, carbon ring seals, labyrinth seals, and dry gas seals are widely used in some compressors, expanders, fans, and other equipment. The traditional sealing structure is used alone and has certain defects in use. Commonly used dry gas seals can achieve zero leakage of the sealing medium, but traditional dry gas seals have strict requirements on the sealing gas. The gas medium of the sealing system is not allowed to be mixed with impurities such as liquids and particles. The sealing control system is complex, and the specification parameters of the system material are also required to be higher. Especially under high line speed conditions, the requirements for dry gas seals are more stringent. Carbon ring seals and labyrinth seals alone cannot achieve zero leakage of the sealing medium, but can only reduce the leakage of the sealing medium.

[0003] The above information disclosed in the background technology is only used to increase the understanding of the background technology of the present application, and therefore, it may include information that does not constitute the prior art known to ordinary technicians in the field. Summary of the invention

[0004] In view of the above-mentioned problems in the prior art, the present invention proposes a sealing device for high linear speed working conditions, which can effectively prevent the leakage of sealing medium by arranging a centrifugal seal and a spiral seal between the rotating shaft and the sealing body. The centrifugal force generated by the high linear speed is used to strengthen the sealing method, so that the sealing device can adapt well to the high linear speed working conditions, and effectively solves the problem of sealing difficulty under high linear speed.

[0005] In order to achieve the above-mentioned purpose, the present invention adopts the following technical solutions: A sealing device for high line speed working conditions, comprising: Axis of rotation; A sealing body, which is sleeved on the outer side of the rotating shaft; A centrifugal seal close to the medium side and a spiral seal close to the atmosphere side are arranged side by side between the rotating shaft and the sealing body; The centrifugal seal comprises a centrifugal ring extending radially outwardly along the rotating shaft, a first sealing cavity opened on the sealing body and used to accommodate the centrifugal ring, the centrifugal ring is rotatably located in the first sealing cavity; a U-shaped flow channel for fluid flow is formed between the centrifugal ring and the first sealing cavity; An isolation liquid is provided at the spiral seal, and the spiral seal is used to transport the isolation liquid toward the centrifugal seal direction; In the working state, the contact surface between the sealing medium and the isolation liquid forms a sealing liquid ring, and the sealing liquid ring is located in the U-shaped flow channel.

[0006] In some embodiments of the present application, under working conditions, the rotating shaft rotates, driving the isolation fluid at the spiral seal to be transported in the direction of the centrifugal seal, and the sealing medium and isolation fluid on both sides of the centrifugal ring flow outward into the U-shaped flow channel under the action of centrifugal force, forming a pressure-balanced sealing liquid ring in the U-shaped flow channel.

[0007] In some embodiments of the present application, by adjusting the rotation speed of the rotating shaft and selecting an isolation liquid with a suitable viscosity, pressure balance can be achieved at the sealing liquid ring to achieve zero leakage of the sealing medium.

[0008] In some embodiments of the present application, a monitoring oil cup connected to the spiral seal is connected to the sealing body for supplying isolation fluid.

[0009] In some embodiments of the present application, the centrifugal ring has a radially extending portion, and an axially extending portion extending axially is provided at an outer end of the radially extending portion.

[0010] In some embodiments of the present application, the distance between the centrifugal ring and the first sealing cavity is 1 to 10 mm.

[0011] In some embodiments of the present application, the ratio of the axial dimension of the axially extending portion to the axial dimension of the radially extending portion is 1 / 2 to 3 / 4.

[0012] In some embodiments of the present application, the radial dimension of the centrifugal ring is 1 / 4 to 3 / 8 of the outer diameter of the rotating shaft.

[0013] In some embodiments of the present application, the first sealing cavity is an annular groove structure extending radially outward, and the size of the first sealing cavity in the axial direction is larger than the size of the axially extending portion.

[0014] In some embodiments of the present application, the spiral seal is a spiral groove opened on the inner diameter end surface of the seal body, the spiral groove is spaced apart from the rotating shaft, and an isolation fluid is filled between the spiral groove and the rotating shaft.

[0015] In some embodiments of the present application, a carbon ring seal is also included, wherein the carbon ring seal has a second sealing chamber close to the medium side and a third sealing chamber close to the air side opened on the sealing body, a second carbon ring located in the second sealing chamber, and a third carbon ring located in the third sealing chamber, and the centrifugal seal and the spiral seal are located between the second sealing chamber and the third sealing chamber.

[0016] In some embodiments of the present application, the second carbon ring has a plurality of circumferentially arranged petals, and two adjacent petals are overlapped, and a second spring for pushing the second carbon ring to move toward the medium side is provided in the second sealing cavity; a radially retractable second tight hoop is provided on the outer side of the second carbon ring.

[0017] In some embodiments of the present application, a plurality of dynamic pressure grooves and a connecting groove arranged circumferentially and connected to the dynamic pressure grooves are provided on the inner diameter end surface of the second carbon ring, the connecting grooves are located close to the medium side, and an axial fluid inlet is provided on the side of the dynamic pressure groove away from the connecting groove.

[0018] In some embodiments of the present application, the dynamic pressure grooves are symmetrically arranged along the axial direction, the radial depth of the dynamic pressure grooves is 0.5 to 2 mm, and the axial dimension of the dynamic pressure grooves is 2 / 3 to 4 / 5 of the axial dimension of the carbon ring.

[0019] In some embodiments of the present application, in a working state, the multiple petals of the carbon ring are separated from each other, so that a gap is generated between the inner diameter end surface of the carbon ring and the rotating shaft, and the gap is between 0.1 and 0.3 mm.

[0020] In some embodiments of the present application, a coating of a high hardness material is sprayed on the rotating shaft, and the coating is located on the inner side of the carbon ring.

[0021] Compared with the prior art, the advantages and positive effects of the present invention are: by arranging a centrifugal seal and a spiral seal between the rotating shaft and the sealing body, the sealing medium can be effectively prevented from leaking. In the working state, the rotation of the rotating shaft can drive the isolation liquid at the spiral seal to be transported in the direction of the centrifugal seal, so that the pressure of the isolation liquid increases during the transportation process; in the working state, the pressure of the sealing medium is relatively high, and it has a tendency to flow to the air side. A U-shaped flow channel for fluid flow is formed between the centrifugal ring and the first sealing chamber, and the sealing medium and the isolation liquid flow into the U-shaped flow channel. The contact surface pressure of the sealing medium and the isolation liquid is balanced to form a stable sealing liquid ring. The centrifugal force generated by the high linear speed is used to strengthen the seal, so that the sealing device can adapt well to the high linear speed working conditions, and effectively solves the problem of sealing difficulties under high linear speeds.

[0022] After reading the specific embodiments of the present invention in conjunction with the accompanying drawings, other features and advantages of the present invention will become more clear. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0024] Figure 1 This is a schematic structural diagram of an embodiment of a sealing device for high linear speed working conditions proposed by the present invention; Figure 2 for Figure 1 An enlarged structural diagram of the centrifugal seal in the middle; Figure 3 It is a schematic diagram of a part of the structure of the inner diameter end surface of the second carbon ring; Figure 4 for Figure 1 Schematic diagram of pressure balance; Among them, the sealing device 100; Rotating shaft 10; sealing body 20; Centrifugal seal 30; centrifugal ring 31; radial extension portion 311; axial extension portion 312; first sealing cavity 32; U-shaped flow channel 33; sealing liquid ring 34; Spiral seal 40; monitoring oil cup 50; Carbon ring seal 60; second sealing chamber 61; second carbon ring 62; dynamic pressure groove 621; fluid inlet 6211; connecting groove 622; second spring 63; second clamp 64; third sealing chamber 65; third carbon ring 66. DETAILED DESCRIPTION

[0025] To make the purpose, technical solution and advantages of the embodiments of the present invention more clear, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention.

[0026] In the description of the present invention, it should be noted that the directions or positional relationships indicated by the terms "upper", "lower", "left", "right", etc. are based on the positional relationships shown in the accompanying drawings, with the direction closer to the axis of rotation being "inside", and the opposite being "outside". The terms are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as a limitation on the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance; features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "multiple" is two or more, unless otherwise clearly and specifically defined.

[0027] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0028] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0029] The disclosure below provides many different embodiments or examples to implement different structures of the present invention. In order to simplify the disclosure of the present invention, the parts and settings of specific examples are described below. Of course, they are only examples, and the purpose is not to limit the present invention. In addition, the present invention can repeat reference numbers and / or reference letters in different examples, and this repetition is for the purpose of simplicity and clarity, which itself does not indicate the relationship between the various embodiments and / or settings discussed. In addition, the present invention provides various specific examples of processes and materials, but those of ordinary skill in the art can appreciate the application of other processes and / or the use of other materials.

[0030] Wherever possible, the various aspects and features described and shown in the specification may be applied separately and these separate aspects may be made the subject of divisional applications.

[0031] See also Figure 1-Figure 4, is an embodiment of a sealing device for high linear speed working conditions proposed by the present invention, a sealing device for high linear speed working conditions 100 comprises: a rotating shaft 10 and a sealing body 20, the sealing body 20 is sleeved on the outer side of the rotating shaft 10, and the sealing body 20 is fixedly arranged. A centrifugal seal 30 and a spiral seal 40 are arranged side by side in the axial direction, the centrifugal seal 30 is close to the medium side, and the spiral seal 40 is close to the atmosphere side. The centrifugal seal 30 has a centrifugal ring 31 extending outwardly along the radial direction of the rotating shaft 10, and a first sealing cavity 32 opened on the sealing body 20, the first sealing cavity 32 is used to accommodate the centrifugal ring 31, and the centrifugal ring 31 is rotatably located in the first sealing cavity 32.

[0032] A U-shaped flow channel 33 for fluid flow is formed between the centrifugal ring 31 and the first sealing cavity 32. A spacer liquid is provided at the spiral seal 40, and the spiral seal 10 is used to transport the spacer liquid toward the centrifugal seal 30. In the working state, the contact surface between the sealing medium and the spacer liquid forms a sealing liquid ring 34, and the sealing liquid ring 34 is located in the U-shaped flow channel 33.

[0033] In this embodiment, by arranging a centrifugal seal 30 and a spiral seal 40 between the rotating shaft 10 and the sealing body 20, the leakage of the sealing medium can be effectively prevented. In the working state, the rotation of the rotating shaft 10 can drive the isolation liquid at the spiral seal 40 to be transported in the direction of the centrifugal seal 30, so that the pressure of the isolation liquid increases during the transportation process; in the working state, the pressure of the sealing medium is relatively high, and it has a tendency to flow to the air side. A U-shaped flow channel 33 for fluid flow is formed between the centrifugal ring 31 and the first sealing cavity 32, and the sealing medium and the isolation liquid flow into the U-shaped flow channel 33. The contact surface pressure of the sealing medium and the isolation liquid is balanced to form a stable sealing liquid ring 34. The sealing liquid ring can automatically adjust its position according to the change of the pressure difference, so as to always maintain a good sealing state and effectively prevent the leakage of the sealing medium. The method of strengthening the sealing by using the centrifugal force generated by the high linear speed enables the sealing device 100 to adapt well to the high linear speed working condition, effectively solves the problem of sealing difficulty under high linear speed, and achieves zero leakage.

[0034] In some embodiments of the present application, in the working state, the rotating shaft 10 rotates, driving the isolation liquid at the spiral seal 40 to be transported in the direction of the centrifugal seal 30; and the sealing medium and isolation liquid on both sides of the centrifugal ring 31 flow outward into the U-shaped flow channel 33 under the action of centrifugal force, forming a pressure-balanced sealing liquid ring 34 in the U-shaped flow channel 33. The sealing medium and isolation liquid form a pressure-balanced sealing liquid ring in the U-shaped flow channel through centrifugal force. This dynamic balance sealing method can adapt to the pressure changes in the working process; the sealing liquid ring can automatically adjust its position according to the change of the pressure difference, so as to always maintain a good sealing state and effectively prevent the leakage of the sealing medium. In the working process, the rotation of the rotating shaft is continuous and stable (under the normal operation of the equipment), and this stable power source can continuously transport the isolation liquid at the spiral seal 40 to the direction of the centrifugal seal 30, and the centrifugal force is also relatively stable; therefore, once the sealing liquid ring is formed, it can work in a relatively stable state, reducing the risk of sealing failure. The stable sealing state can ensure the stable operation of the equipment and reduce the probability of equipment failure caused by sealing problems. The pressure-balanced sealing liquid ring 34 can make the contact between the sealing components more stable, reduce the wear of the sealing components, extend the service life of the sealing components, and improve the reliability of the entire sealing device.

[0035] In some embodiments of the present application, the sealing medium is preferably set to gas, and the sealing liquid ring 34 is the contact surface between the gas and the liquid; the mixing of the sealing medium and the isolation liquid at the sealing liquid ring 34 is avoided.

[0036] In some embodiments of the present application, by adjusting the rotation speed of the rotating shaft 10 and selecting the appropriate viscosity of the isolation liquid, the pressure balance at the sealing liquid ring 34 can be achieved, and zero leakage of the sealing medium can be achieved. According to the specific needs of the actual working conditions, the rotation speed of the rotating shaft can be flexibly adjusted and the isolation liquid of the appropriate viscosity can be selected to accurately promote the pressure balance at the sealing liquid ring, thereby achieving zero leakage of the sealing medium. By constantly trying different combinations of rotation speed and isolation liquid viscosity, the sealing parameter setting that best suits the specific equipment and working conditions can be found, so that the sealing effect reaches the optimal state, and the problems caused by the leakage of the sealing medium are minimized or even eliminated. The sealing medium can be circulated and played in the equipment completely as expected, realizing efficient use of resources. Whether it is high line speed, high pressure or complex working conditions such as different temperatures, as long as the rotation speed of the rotating shaft is reasonably adjusted and the viscosity of the isolation liquid is selected, it is possible to achieve an ideal pressure balance and zero leakage state, so that the sealing device can be widely used in many industries with strict sealing requirements and diverse working conditions. On different types of equipment.

[0037] In some embodiments of the present application, a monitoring oil cup 50 connected to the spiral seal 40 is connected to the sealing body 20 for supplying isolation liquid. The monitoring oil cup 50 is a transparent cup-shaped funnel-shaped structure, and the outer circle of the monitoring oil cup 50 has scale lines, which can monitor the seal in real time, and can also play the role of replenishing oil when there is a slight loss of isolation liquid. It can ensure that there is enough isolation liquid at the spiral seal 40 to maintain its normal sealing function, and ensure that the isolation liquid can be continuously transported to the centrifugal seal 30, thereby maintaining the pressure balance at the sealing liquid ring 34, and ensuring that the zero leakage state of the sealing medium is sustained. By monitoring the sealing condition in real time, once a slight abnormality occurs in the sealing system, it can be detected as early as possible from signs such as changes in the liquid level of the monitoring oil cup, and fault detection and repair can be carried out in advance. Real-time monitoring and oil replenishment functions ensure the reliable operation of the sealing device.

[0038] See also Figure 4 , is a schematic diagram of the sealing device 100 for achieving zero leakage. When the sealing device 100 is in working state, the radial clearance ∆h between the spiral seal 40 and the rotating shaft 10 is (0.2-1) mm, the radius of the liquid surface on the medium side of the centrifugal ring 31 is R2, the outer diameter of the rotating shaft 10 is R1, the spiral seal length from the monitoring oil cup to the centrifugal ring is L2, the spiral seal length from the monitoring oil cup to the atmosphere is L1, the liquid level height of the monitoring oil cup is h1, the angular velocity of the rotating shaft and the centrifugal ring is ω, the density of the lubricating oil is ρkg / m3, the medium pressure is P2, the pressure at the bottom of the monitoring oil cup is P1, and the atmospheric pressure is P0. At this time, the pressure of the contact surface between the medium and the isolation liquid at the centrifugal ring is balanced, and then: P2=P1+ P′+ P″ --P' is the centrifugal pressure of the centrifugal ring -- P″ is the pressure increase of the spiral seal with length L2 P1=ρgh1= k3l1μωR1 / ∆h² P′=0.15[ρω² (R2²-R1²)].

[0039] P″= k3l2μωR1 / ∆h² --k3 is the structural parameter of the spiral seal The sealing liquid will achieve pressure balance at the liquid seal ring surface, and the liquid seal ring will ensure that the gas medium will not leak, thus playing an effective sealing role and completely solving the leakage problem. P2= k3l1μωR1 / Δh ² +0.15[ρω² (R2²-R1²)]+k3l2μωR1 / Δh ² The simplified formula is P2=f(ω,μ). It can be seen that the medium pressure P2 is related to the rotation speed ω and the viscosity of the sealing liquid. Therefore, in the sealing device 100, the pressure balance at the sealing liquid ring 34 can be achieved by adjusting the rotation speed and selecting a suitable viscosity of the isolation liquid to achieve zero leakage of the sealing medium. The position of the sealing liquid ring 34 can also be changed by adjusting the rotation speed and selecting a suitable viscosity of the isolation liquid.

[0040] In some embodiments of the present application, the centrifugal ring 31 has a radial extension portion 311, and an axial extension portion 312 extending axially is provided at the outer end of the radial extension portion 311. The radial extension portion 311 extends outward along the radial direction of the rotating shaft, and can block and guide the sealing medium and the isolation liquid in the radial direction, so that they flow more smoothly into the U-shaped flow channel under the action of centrifugal force, which helps to form a stable sealing liquid ring and enhance the sealing effect in the radial direction. The axial extension portion 312 extends axially, which can further limit the flow range of the sealing medium and the isolation liquid from the axial dimension to prevent them from escaping from the axial direction, and cooperates with the radial extension portion to achieve multi-dimensional sealing, thereby improving the ability of the entire sealing device to prevent leakage under complex working conditions. The axial extension portion 312 extends from the outer end of the radial extension portion 311, which increases the overall structural complexity of the centrifugal ring, making it no longer a simple single-dimensional structure, which is equivalent to adding additional support and reinforcement parts to the centrifugal ring 31; and the centrifugal ring 31 rotates at high speed with the rotating shaft 10, which increases the centrifugal pumping effect on the fluid.

[0041] In some embodiments of the present application, the spacing between the centrifugal ring 31 and the first sealing cavity 32 is 1 to 10 mm. For high linear speed working conditions, the appropriate spacing can ensure that the fluid can flow into the U-shaped flow channel 33 quickly and orderly under the action of centrifugal force. The spacing between the centrifugal ring 31 and the first sealing cavity 32 is 1 to 10 mm. This range can provide sufficient space for the flow of the sealing medium and the isolation liquid under the action of centrifugal force. If the spacing is too small, the fluid may be hindered when flowing into the U-shaped flow channel 33, resulting in a large flow resistance, and may even cause excessive local pressure, destroying the pressure balance of the sealing liquid ring. If the spacing is too large, on the one hand, the overall volume of the sealing device 100 will increase, and on the other hand, it may cause the centrifugal force to weaken the restraining effect on the fluid, which is not conducive to the formation and stability of the sealing liquid ring.

[0042] In some embodiments of the present application, the ratio of the axial dimension of the axial extension portion 312 to the axial dimension of the radial extension portion 311 is 1 / 2 to 3 / 4. This ratio range helps to balance the sealing effect of the centrifugal ring in the axial and radial directions. If the axial extension portion 312 is too long, it may cause the blocking effect on the sealing medium and the isolation liquid in the axial direction to be too strong, while the sealing effect in the radial direction is relatively weakened, and vice versa. Such a ratio can achieve better synergy in the sealing effect of the centrifugal ring 31 in two directions, thereby enhancing the overall sealing performance.

[0043] In some embodiments of the present application, the radial dimension of the centrifugal ring 31 is 1 / 4 to 3 / 8 of the outer diameter of the rotating shaft 10. This size ratio ensures the sealing performance while facilitating the processing and manufacturing of the centrifugal ring 31. The appropriate size can reduce the processing difficulty and cost, and is also convenient for installation and maintenance.

[0044] In some embodiments of the present application, the first sealing cavity 32 is an annular groove structure extending radially outward, and the size of the first sealing cavity 32 in the axial direction is larger than the size of the axial extension portion. The first sealing cavity 32 is arranged to have equal axial width, which is conducive to the centrifugal ring 31 extending into the first sealing cavity 32. The first sealing cavity 32 is arranged to have equal axial width, forming a regular and uniform accommodating space, which enables the centrifugal ring to extend therein more smoothly during installation. When the equipment is running, even if it is affected by factors such as changes in the pressure of the sealing medium and slight vibrations of the rotating shaft 10, the centrifugal ring 31 still has sufficient room for movement in the axial direction. At the same time, in conjunction with its own axial extension portion 312, it can better limit and guide the sealing medium and the isolation liquid in the axial direction, further strengthening the axial sealing effect and improving the sealing reliability of the entire sealing device.

[0045] In some embodiments of the present application, the spiral seal 40 is a spiral groove opened on the inner diameter end surface of the sealing body 20 , the spiral groove is spaced apart from the rotating shaft 10 , and the isolation fluid is filled between the spiral groove and the rotating shaft 10 .

[0046] In some embodiments of the present application, the sealing device 100 further includes a carbon ring seal 60, which has a second sealing cavity 61 and a third sealing cavity 65 opened on the sealing body 20, a second carbon ring 62 located in the second sealing cavity 61, and a third carbon ring 66 located in the third sealing cavity 65, wherein the second sealing cavity 61 is close to the medium side, and the third sealing cavity 65 is close to the air side. The centrifugal seal 30 and the spiral seal 40 are located between the second sealing cavity 61 and the third sealing cavity 65. The carbon ring seal 60 is provided with a second sealing cavity 61 close to the medium side and a second carbon ring 62 therein, and a third sealing cavity 65 and a third carbon ring 66 close to the air side, and the centrifugal seal 30 and the spiral seal 40 located therebetween jointly construct multiple sealing defense lines. From the sealing medium side to the air side, each sealing structure can block the possible leakage of the sealing medium. Even if a certain seal has a slight leakage, the subsequent sealing structure can further intercept it, greatly reducing the possibility of the sealing medium leaking to the outside, so that the overall sealing effect is significantly enhanced, and it is more conducive to achieving the strict requirement of almost zero leakage of the sealing medium. The second carbon ring 62 close to the medium side can take the lead in blocking the sealing medium leaking from the inside of the equipment to the outside, preventing a large amount of medium from directly breaking through the sealing defense line. The third carbon ring 66 close to the air side can effectively block the impurities such as the outside air from entering the inside of the equipment in the reverse direction, and can also further prevent the medium that has passed through the previous sealing structure but still leaks a small amount from continuing to seep out. Under high linear speed conditions, the centrifugal seal 30 and the spiral seal 40 use the centrifugal force generated by rotation to effectively seal, and the carbon ring seal 60 can also assist in maintaining the overall sealing stability, so that the device can be widely used in equipment under various harsh working conditions.

[0047] In some embodiments of the present application, the second carbon ring 62 has a plurality of circumferentially arranged petals, and two adjacent petals are overlapped, so that the structure enables the carbon ring to better adapt to the slight deformation, eccentric movement, etc. of the rotating shaft under different working conditions. A second spring 63 is provided in the second sealing cavity 61 to push the second carbon ring 62 to move toward the medium side; ensure that the second carbon ring 62 is always tightly fitted on the cavity wall of the second sealing cavity 62 close to the medium side to achieve dynamic sealing. A radially retractable second tight hoop 64 is provided on the outside of the second carbon ring 62. The radially retractable second tight hoop 64 is provided on the outside of the second carbon ring 62, which can further enhance the sealing performance of the second carbon ring 62. The second tight hoop 64 can apply a certain clamping force to the second carbon ring 62 in the radial direction, so that the second carbon ring 62 is subjected to the thrust of the second spring 63 and the pressure of the sealing medium, and its own structure is more compact and stable.

[0048] In some embodiments of the present application, see Figure 3As shown, a plurality of dynamic pressure grooves 621 and a connecting groove 622 arranged circumferentially and connected to the plurality of dynamic pressure grooves 621 are provided on the inner diameter end surface of the second carbon ring 62. The connecting groove 622 is located close to the medium side, and the dynamic pressure groove 621 is provided with an axial fluid inlet 6211 on the side away from the connecting groove 622. A plurality of dynamic pressure grooves 621 are provided on the inner diameter end surface of the second carbon ring 62. When the rotating shaft 10 rotates, the sealing medium will generate a dynamic pressure effect in the dynamic pressure groove 621, which can make the sealing medium form a layer of fluid film with a certain pressure. This layer of fluid film can effectively prevent the sealing medium from leaking from the gap between the carbon ring and the rotating shaft. The connecting groove 622 is arranged circumferentially and connected with multiple dynamic pressure grooves 621, and is located close to the medium side, so that the sealing medium can enter the dynamic pressure groove 621 more smoothly, ensuring that there is enough medium in the dynamic pressure groove 621 to produce a dynamic pressure effect; at the same time, the arrangement of the connecting groove 622 can balance the medium pressure between each dynamic pressure groove 621, so that the medium distribution in the dynamic pressure groove 621 is more uniform, avoiding the influence of the sealing effect due to excessively high or too low local pressure. When the sealing medium pressure is low, the fluid inlet 6211 can guide more medium into the dynamic pressure groove 621 to generate sufficient dynamic pressure to maintain the seal.

[0049] In some other embodiments of the present application, the dynamic pressure groove 621 may also adopt other structural shapes.

[0050] In some embodiments of the present application, the dynamic pressure groove 621 is symmetrically arranged along the axial direction, and can realize bidirectional rotation of the rotating shaft, so that no matter whether the rotating shaft 10 rotates forward or reverse, an effective dynamic pressure effect can be generated in the dynamic pressure groove 621, thereby achieving a good sealing effect. The radial depth of the dynamic pressure groove 621 is 0.5 to 2 mm, and the axial dimension of the dynamic pressure groove 621 is 2 / 3 to 4 / 5 of the axial dimension of the carbon ring 62.

[0051] In some embodiments of the present application, in the working state, the multiple petals of the second carbon ring 62 are separated from each other, so that a gap is generated between the inner diameter end surface of the second carbon ring 62 and the rotating shaft 10, and the gap is between 0.1 and 0.3 mm.

[0052] In some embodiments of the present application, a coating of a high-hardness material is sprayed on the rotating shaft 10, and the coating is located on the inner side of the second carbon ring 62. During the operation of the device, even if there is a certain gap between the rotating shaft 10 and the second carbon ring 62, there will still be relative movement and contact; the coating of the high-hardness material can significantly increase the hardness of the rotating shaft surface, making it more resistant to the force generated by friction, extrusion, etc. between the rotating shaft 10 and the second carbon ring 62, and effectively reducing the wear of the rotating shaft 10 itself.

[0053] In some embodiments of the present application, the structure of the third carbon ring 66 may be similar to that of the second carbon ring 62 .

[0054] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, it is still possible for a person skilled in the art to modify the technical solutions described in the aforementioned embodiments, or to replace some of the technical features therein by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions claimed to be protected by the present invention.

Claims

1. A sealing device for high line speed working conditions, characterized in that: include: Axis of rotation; A sealing body, which is sleeved on the outer side of the rotating shaft; A centrifugal seal close to the medium side and a spiral seal close to the atmosphere side are arranged side by side between the rotating shaft and the sealing body; The centrifugal seal comprises a centrifugal ring extending radially outwardly along the rotating shaft, a first sealing cavity opened on the sealing body and used to accommodate the centrifugal ring, the centrifugal ring is rotatably located in the first sealing cavity; a U-shaped flow channel for fluid flow is formed between the centrifugal ring and the first sealing cavity; An isolation liquid is provided at the spiral seal, and the spiral seal is used to transport the isolation liquid toward the centrifugal seal direction; In the working state, the contact surface between the sealing medium and the isolation liquid forms a sealing liquid ring, and the sealing liquid ring is located in the U-shaped flow channel.

2. The sealing device according to claim 1, characterized in that: In the working state, the rotating shaft rotates, driving the isolation fluid at the spiral seal to be transported in the direction of the centrifugal seal, and the sealing medium and isolation fluid on both sides of the centrifugal ring flow outward into the U-shaped flow channel under the action of centrifugal force, forming a pressure-balanced sealing liquid ring in the U-shaped flow channel.

3. The sealing device according to claim 1, characterized in that: By adjusting the rotation speed of the rotating shaft and selecting a suitable viscosity of the isolation liquid, the pressure balance at the sealing liquid ring can be achieved, thereby realizing zero leakage of the sealing medium.

4. The sealing device according to claim 1, characterized in that: A monitoring oil cup connected to the spiral seal is connected to the sealing body and is used to supply isolation fluid.

5. The sealing device according to claim 1, characterized in that: The centrifugal ring has a radially extending portion, and an axially extending portion extending axially is arranged at an outer end of the radially extending portion.

6. The sealing device according to claim 1, characterized in that: The first sealing cavity is an annular groove structure extending radially outward, and the size of the first sealing cavity in the axial direction is larger than the size of the axially extending portion.

7. The sealing device according to claim 1, characterized in that: The spiral seal is a spiral groove opened on the inner diameter end surface of the seal body, the spiral groove is spaced apart from the rotating shaft, and the isolation fluid is filled between the spiral groove and the rotating shaft.

8. The sealing device according to claim 1, characterized in that: It also includes a carbon ring seal, which has a second sealing chamber close to the medium side and a third sealing chamber close to the air side opened on the sealing body, a second carbon ring located in the second sealing chamber, and a third carbon ring located in the third sealing chamber, and the centrifugal seal and the spiral seal are located between the second sealing chamber and the third sealing chamber.

9. The sealing device according to claim 1, characterized in that: The second carbon ring has a plurality of circumferentially arranged petals, and two adjacent petals are overlapped. A second spring for pushing the second carbon ring to move toward the medium side is arranged in the second sealing cavity; a radially retractable second tight hoop is arranged on the outer side of the second carbon ring.

10. The sealing device according to claim 1, characterized in that: The inner diameter end surface of the second carbon ring is provided with a plurality of dynamic pressure grooves and a connecting groove arranged circumferentially and connected to the dynamic pressure grooves. The connecting grooves are located close to the medium side. The dynamic pressure grooves are provided with an axial fluid inlet on the side away from the connecting grooves.

Images