Leakage-free sealing device

Abstract

The invention provides a leakage-free sealing device which is used for sealing shaft structures and comprises a mechanical sealing inner sealing assembly arranged on the periphery of a shaft in a sleeving mode, the outer periphery of the mechanical sealing inner sealing assembly is sleeved with a leakage absorption assembly in a matched mode, the leakage absorption assembly comprises a cavity gland provided with a hollow cavity, and the cavity gland is in an annular shape; a drainage structure which enables a hollow cavity of the cavity gland to be communicated with an oil way of the mechanical sealing inner sealing assembly is arranged on the side wall of the cavity gland, and a polymer filling block used for absorbing liquid is arranged in the hollow cavity of the cavity gland. Conventional leaked oil of the mechanical sealing inner sealing assembly under the normal working condition is introduced into the cavity of the cavity gland to be absorbed, so that it is guaranteed that no observable leakage occurs outside the shaft type structure within a certain time period or in the equipment overhaul period; and the polymer filling blocks for absorbing the liquid can be cleaned or replaced during fixed-period maintenance.

Description

Technical Field

[0001] The present invention relates to the technical field of sealing structures of aerospace or deep-sea operating equipment, and in particular to a leakage-free sealing device. Background Art

[0002] At present, various detection operation machinery involved in the aerospace field and deep-sea operation field involves rotating shafts or other similar rotating structures, such as: reducers of turboshaft turboprop turbofan engines, auxiliary power equipment, starters, detection device drive motors, etc., which are prone to sealing problems when facing harsh working conditions.

[0003] For example, aircraft engines are prone to micro-deformation due to high temperature in the later stages of their service life, and are prone to leakage at the seals. During inspection and maintenance, trace amounts of medium leakage will be found in the casing, requiring additional cleaning steps and inspection and maintenance procedures. In deep-sea mechanical equipment, the mechanical seal of the drive device is generally only suitable for pressure conditions of 6MPa to 15MPa. Seawater is on the outside of the motor, and the mechanical seal is responsible for isolating the seawater from the rotor inside the motor. If the mechanical seal leaks, especially under high-pressure conditions, seawater will enter the motor cavity, causing the motor to short-circuit and burn. To avoid this, it is also necessary to regularly clean the structure near the motor shaft, increasing the frequency and maintenance procedures of the motor.

[0004] According to the national standard GB / T 4127, the traditional mechanical seal allows visible leakage. According to this standard, the permissible leakage value is: when the medium is liquid, the leakage flow range allowed for the sealing structure with an ambient pressure range of 0-5Mpa and a shaft diameter less than 50mm is: within 3ml / h; when the shaft diameter range of the sealing structure is 50mm≤d≤120mm, the permissible leakage flow is 3ml / h-5ml / h. When the ambient pressure range is 5MPa-10MPa, the leakage flow range allowed for the sealing structure with a shaft diameter less than 50mm is: within 15ml / h; when the shaft diameter range of the sealing structure is 50mm≤d≤120mm, the permissible leakage flow range is: 15ml / h-20 ml / h. Obviously, the conventional national standard requirements cannot meet the high sealing requirements of mechanical equipment in the aerospace and deep-sea fields. In the above two fields, for the sake of system safety, there is a technical requirement for no visible leakage within a certain inspection and maintenance cycle.

[0005] In summary, the existing sealing design of rotating parts of mechanical equipment has the problem of being difficult to meet the technical requirements of no visible leakage at regular periods in the aerospace and deep-sea fields. Summary of the invention

[0006] The technical problem to be solved by the present invention is that the existing sealing design of rotating parts of mechanical equipment is difficult to meet the technical requirements of no visible leakage at regular periods in the aerospace and deep-sea fields.

[0007] In order to solve the above problems, the present invention provides a leakage-free sealing device for sealing shaft structures, including a mechanical seal inner seal assembly sleeved on the outer periphery of the shaft, the outer peripheral edge of the mechanical seal inner seal assembly is sleeved with a leakage absorption assembly, the leakage absorption assembly includes a cavity pressure cover with a hollow cavity, the cavity pressure cover is annular, and the inner peripheral wall of the cavity pressure cover is provided with a drainage structure that connects the hollow cavity with the oil circuit of the mechanical seal inner seal assembly, and a polymer filling block for absorbing liquid is provided in the hollow cavity.

[0008] The novel sealing design provided by the present invention mainly comprises two main parts, namely a mechanical seal inner seal component sleeved on the outer periphery of the shaft and a leakage absorption component, wherein the two are connected to each other, and through the polymer filling block in the cavity gland structure of the leakage absorption component and the setting of the drainage structure, the conventional leakage oil of the mechanical seal inner seal component under normal working conditions is introduced into the cavity of the cavity gland for absorption. When the normal engine oil leakage around the shaft equipment in the aerospace field reaches the position where the outer wall of the shaft is prone to accumulation and leakage, the oil enters the cavity gland structure through the drainage structure, and avoids the accumulation of impurities on the surface of the shaft or the infiltration of the position where the oil should not exist in the motor; and in deep-sea operating equipment, the corresponding leakage in this process is generally seawater or a mixture of seawater and engine oil that leaks from the outside of the motor to the inside of the motor. When the same leakage reaches the space between the cavity gland and the mechanical seal inner seal component, it is guided into the cavity gland through the drainage structure and absorbed.

[0009] This structure ensures that within a certain period of time or within the maintenance cycle of the equipment, there will be no observable oil leakage on the outside of the shaft structure. It is only necessary to clean or replace the polymer filling blocks used to absorb liquid during regular periodic maintenance. This effectively solves the problem that the sealing design of existing mechanical equipment rotating parts is difficult to meet the technical requirements of no visible leakage at regular intervals in the aerospace and deep-sea fields.

[0010] As a preferred solution, the mechanical seal inner seal assembly includes a first sleeve and a first movable ring and a first stationary ring sleeved on the first sleeve, an annular protrusion is provided on the outer peripheral wall of the first sleeve, the first movable ring is mounted and fixed to the protrusion by a first pin, the first stationary ring is circumferentially positioned and connected to the inner peripheral wall of the cavity pressure cover, and is elastically matched through an axially arranged compression spring, and the end faces of the first movable ring and the first stationary ring are abutted against each other through the elastic force provided by the compression spring.

[0011] This design optimizes the structure of the above-mentioned mechanical inner sealing component, mainly including a first dynamic ring and a first static ring part which are sleeved on the first sleeve. One of the two is installed and fixed to the edge of the annular mounting groove on the outer peripheral surface of the first sleeve, and is fixed by evenly arranged pins. The other is elastically matched with the cavity pressure cover, and is circumferentially positioned by a pin-type structure to prevent relative rotation between the first static ring and the cavity pressure cover. A compression spring structure is arranged between the first static ring and the cavity pressure cover to provide elastic force to press the end faces of the first static ring and the first dynamic ring against each other to obtain a basic mechanical sealing effect.

[0012] As a preferred solution, the inner circumferential wall of the cavity gland is provided with an annular recessed groove, and an annular ring seat structure is provided in the recessed groove. The ring seat structure is circumferentially positioned and matched with the cavity gland through a second pin, and the two ends of the compression spring are respectively against the end face of the ring seat structure and the recessed groove, and the first stationary ring is fixed to the end face of the ring seat structure away from the compression spring through a third pin. This design optimizes the matching mode between the first stationary ring and the cavity gland, and an annular ring seat structure is provided on the inner side edge of the cavity gland, that is, between the cavity gland and the first sleeve, for installing the first stationary ring, and the ring seat and the first stationary ring are circumferentially fixed by pins.

[0013] As a preferred solution, one axial end of the hollow cavity of the cavity gland is closed and the other end is open, and a gland cover plate for closing the hollow cavity is detachably installed at the open end. This design optimizes the structure of the cavity gland, and the cavity gland is a structure in which one end is closed and the other end is open, and a gland cover plate is provided to close the opening in accordance with the size and shape of the opening, and the gland cover plate is detachably installed, which can be specifically implemented by means of screws, etc. This design can conveniently inspect and replace the polymer filling block filled in the cavity gland, greatly reducing the difficulty of inspection and maintenance.

[0014] As a preferred solution, the cavity gland is provided with an annular sealing plate structure on the outer side of the gland cover plate, and the annular sealing plate structure is fixed to the cavity gland by screws; a positioning ring is fixed to the outer peripheral surface of the first sleeve, and the positioning ring abuts against the end face of the annular sealing plate structure on one side away from the gland cover plate, which is used to axially position the cavity gland. This design optimizes the matching mode between the cavity gland and the first sleeve, and an annular sealing plate structure is provided for the gland cover plate. Through this design, the installation and fixing position of the gland cover plate can be stabilized, and it can be directly fixed to the cavity gland by screws. A positioning ring is set at the corresponding position of the outer peripheral surface of the first sleeve, and the end face of the positioning ring abuts against the annular sealing plate structure to axially position the cavity gland. The positioning ring is preferably installed with the shaft by a pin or screw structure, and the structure of the through hole on the side wall of the first sleeve can be further adopted to fix the pin or screw device used for positioning the positioning ring directly to the shaft body in the first sleeve, and the first sleeve can be axially positioned at the same time in this way.

[0015] As a preferred solution, the cavity pressure cover is provided with an annular barrier sealing structure between its two axial ends and the first sleeve, and the barrier sealing structure located at one end of the pressure cover cover plate is a lip seal, one of the sealing surfaces of the lip seal is in contact with the outer peripheral surface of the first sleeve, and the other sealing surface of the lip seal is in contact with the gap between the cavity pressure cover and the annular sealing plate structure. The design optimizes the sealing and anti-leakage design of the overall axial ends of the sealing device. The key position of the seal is the joint position of the first sleeve and the cavity cover. The barrier sealing structure at one end of the cavity cover is a lip seal. The two adjacent sealing end faces of the lip seal are respectively fitted with the outer peripheral surface of the first sleeve and the inner end face of the annular sealing plate structure to achieve sealing, that is, the setting method of the lip seal is exactly opposite to its conventional installation direction; the barrier seal located at the closed end of the cavity cover is a skeleton oil seal structure. In order to assist the installation of the oil seal structure, a retaining ring or an annular gasket-like structure is preferably provided on the side edge of the corresponding end of the cavity cover to facilitate the cooperation between the end face and the oil seal structure.

[0016] As a preferred solution, a raised first shoulder structure is provided on the outer circumference of the first sleeve adjacent to the lip seal, and the first shoulder structure is opposite to the drainage structure. The first shoulder structure blocks the oil path on the outer circumference of the first sleeve and introduces the leaked liquid into the drainage structure. This design optimizes the internal space within the blocking seal structure at both ends, optimizes the surface structure of the first sleeve in this space, and sets a first shoulder structure with a suitable height to block the leaked oil path on the outer circumference of the first sleeve, so that the end face leakage medium can be effectively blocked, and enters the cavity of the cavity gland through the small hole slot or other forms of drainage structure, and is locked by the polymer filling block.

[0017] As a preferred solution, the mechanical seal inner seal assembly includes a second sleeve, a second moving ring, a second stationary ring and a stationary ring seat, the second sleeve and the second moving ring are both sleeved on the outer circumference of the shaft, a stepped annular slot is provided at one end of the cavity pressure cover, the stationary ring seat is sleeved on the outer circumferential wall of the second sleeve and inserted into the annular slot of the cavity pressure cover, an annular mounting groove is provided on one end face of the stationary ring seat, the outer circumferential wall of the second stationary ring is interference fit with the inner circumferential wall of the mounting groove, a compression spring is provided in the annular slot of the cavity pressure cover, and the compression spring is axially arranged at both ends to respectively press against the cavity pressure cover and the stationary ring seat to provide elastic force to press the end faces of the second stationary ring and the second moving ring against each other.

[0018] This design provides another optional mechanical seal inner seal component, which is suitable for the working environment of aerospace. The second dynamic ring is directly sleeved on the outer circumference of the shaft, and one end face is simultaneously abutted against the end face of the sleeve and the end face of the static ring at different positions, and the static ring is inserted into the annular groove formed between the static ring seat and the sleeve; the cavity pressure cover is fitted with an annular slot on the inner edge of one side of the second sleeve, and the static ring seat has a stepped structure, and its end with a smaller radial dimension is inserted into the slot, and an annular mounting groove is provided at the end with a larger radial dimension, and the static ring is inserted into the groove, and a plurality of spring seats are provided at preset intervals on the end face of the cavity pressure cover so as to set a compression spring to provide elastic force to press the static ring against the dynamic ring.

[0019] As a preferred solution, a flow channel groove for draining leakage is arranged between the inner circumference of each of the second stationary ring and the stationary ring seat and the second sleeve, and a raised second shoulder structure is arranged on the outer circumference of the second sleeve at a position corresponding to the drainage structure on the cavity pressure cover, so as to block the oil path on the outer circumference of the second sleeve.

[0020] This design further optimizes the leakage drainage design inside the inner seal assembly of the mechanical seal, and optimizes the design of introducing the leaked liquid into the space inside the cavity gland. The second stationary ring and the stationary ring seat are provided with flow channel grooves at the inner edge position of the second sleeve for draining the oil. The flow channel grooves are provided with a raised second shoulder structure on the trajectory extending from the outer circumference of the second sleeve and at the position corresponding to the drainage structure of the cavity gland to block the leakage oil path on the second sleeve, so that the end face leakage medium can be effectively blocked and the oil is helped to enter the cavity in the cavity gland through the small holes of the drainage structure.

[0021] As a preferred solution, the inner side wall of the hollow cavity of the cavity gland is integrally connected with a support rib or support grid structure for enhancing the pressure bearing capacity of the cavity gland. This design further optimizes the internal structure of the cavity gland, and the inner side wall of the hollow cavity is provided with a support structure such as a support rib plate or a honeycomb-shaped, three-dimensional grid-shaped structure filled in the cavity. This design is mainly to enhance the pressure bearing strength of the hollow thin-walled cavity gland to avoid damage due to pressure, and the structure occupies as little volume of the polymer filling block in the cavity as possible. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 A schematic cross-sectional structure diagram of a leak-free sealing device provided by the present invention; Figure 2 for Figure 1 A schematic diagram of a partially enlarged cross-section structure of a leak-free sealing device; Figure 3 A schematic cross-sectional structure diagram of another leakage-free sealing device provided by the present invention; Figure 4 for Figure 3A schematic diagram of a partially enlarged cross-section structure of a leak-free sealing device; in, Figure 1-Figure 4 middle: 1. Cavity gland; 1-1. Drainage structure; 1-2. Gland cover plate; 1-3. Annular sealing plate structure; 1-4. Hollow cavity; 1-5. Sink; 2. First sleeve; 2-1. Protrusion; 2-2. Second sleeve; 3. First moving ring; 3-2. Second moving ring; 4. First stationary ring; 4-2. Second stationary ring; 5. Ring seat structure; 5-2. Stationary ring seat; 6. Compression spring; 7. Positioning ring; 8. Barrier seal structure; 9-1. First pin; 9-2. Second pin; 9-3. Third pin; 10-1. First shoulder structure; 10-2. Second shoulder structure; 11. Retaining ring; 12. Screw; 13. Flow channel groove; 14. Sealing ring. DETAILED DESCRIPTION

[0023] In order to make the technical means, creative features, objectives and effects achieved by the present invention easy to understand, the present invention is further explained below in conjunction with specific implementation methods.

[0024] Before explaining the working principle of the present invention in detail, the description of the present invention needs to be further explained: In the description of the present invention, it should be noted that the terms "upper", "lower", "inner", "outer", "front end", "rear end", "two ends", "one end", "the other end" and the like indicate the orientation or position relationship based on the orientation or position relationship shown in the drawings, which is only for the convenience of describing the present invention and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention. In addition, the terms "first" and "second" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance.

[0025] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "provided with", "connected", etc. should be understood in a broad sense. For example, "connected" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, a direct connection, an indirect connection through an intermediate medium, or a welding connection between two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0026] refer to Figure 1 , Figure 2 The following embodiments are described, Figure 1 A schematic cross-sectional structure diagram of a leak-free sealing device provided by the present invention; Figure 2 for Figure 1 A schematic diagram of the partially enlarged cross-section structure of a leak-free sealing device.

[0027] An embodiment of the present invention provides a leakage-free sealing device for sealing shaft structures, including a mechanical seal inner seal assembly sleeved on the outer periphery of the shaft, the outer periphery of the mechanical seal inner seal assembly sleeved with a leakage absorption assembly, the leakage absorption assembly including a cavity pressure cover 1 provided with a hollow cavity 1-4, the cavity pressure cover 1 is annular, and its inner peripheral wall is provided with a drainage structure 1-1 which connects the hollow cavity 1-4 with the oil circuit of the mechanical seal inner seal assembly, and a polymer filling block for absorbing liquid is provided in the hollow cavity 1-4.

[0028] The novel sealing design provided by the present invention mainly comprises two main parts, a mechanical seal inner seal component sleeved on the outer periphery of the shaft and a leakage absorption component, wherein the two are connected to each other. Through the polymer filling block in the cavity pressure cover 1 structure of the leakage absorption component and the setting of the drainage structure 1-1, the conventional leakage oil of the mechanical seal inner seal component under normal working conditions is introduced into the cavity of the cavity pressure cover 1 for absorption, thereby ensuring that within a certain period of time or within the maintenance cycle of the equipment, there is no observable oil leakage outside the shaft structure, and it is only necessary to clean or replace the polymer filling block used for absorbing the liquid during periodic maintenance, which effectively solves the problem that the sealing design of the rotating parts of the existing mechanical equipment is difficult to meet the technical requirements of no visible leakage at regular periods in the aerospace and deep-sea fields.

[0029] The technical solution provided in this embodiment is suitable for sealing applications under deep-sea conditions. The mechanical seal inner seal assembly includes a first sleeve 2 and a first dynamic ring 3 and a first static ring 4 sleeved on the first sleeve 2. An annular protrusion 2-1 is provided on the outer peripheral wall of the first sleeve 2. The first dynamic ring 3 is installed and fixed to the protrusion 2-1 by a first pin 9-1. The first static ring 4 is circumferentially positioned and connected to the inner peripheral wall of the cavity pressure cover 1, and is elastically matched by an axially arranged compression spring 6. The end faces of the first dynamic ring 3 and the first static ring 4 are abutted against each other by the elastic force provided by the compression spring 6.

[0030] On the basis of this structure, the matching structure between the first stationary ring 4 and the cavity gland 1 is further optimized. Among them, the inner circumferential wall of the cavity gland 1 is provided with an annular recessed groove 1-5, and an annular ring seat structure 5 is provided in the recessed groove 1-5. The ring seat structure 5 is circumferentially positioned and matched with the cavity gland 1 through the second pin 9-2, and the two ends of the compression spring 6 are respectively against the end face of the ring seat structure 5 and the recessed groove 1-5. The first stationary ring 4 is installed and fixed to the end face of the ring seat structure 5 away from the compression spring 6 through the third pin 9-3.

[0031] The design optimizes the structure of the mechanical inner seal assembly, which mainly includes a first moving ring 3 and a first stationary ring 4 sleeved on the first sleeve 2. The first sleeve 2 is connected to the first moving ring 3 and is provided with an annular protrusion 2-1. The diameter of the first moving ring 3 is larger than the outer diameter of the first sleeve 2 and matches the radial size of the protrusion. The first moving ring 3 is sleeved on the outside of the first sleeve 2, and the end face of the moving ring fits the end face of the protrusion 2-1 and is fixed with a first pin 9-1. The first pin 9-1 is arranged axially and evenly distributed along the circumference of the first moving ring 3; the first stationary ring 4 is elastically matched with the cavity pressure cover 1. The specific preferred design is that the inner circumferential wall of the cavity pressure cover 1 is provided with an annular recessed groove 1-5 at the position corresponding to the protrusion 2-1, and the central axis of the recessed groove 1-5 coincides with the central axis of the cavity pressure cover 1. The recessed groove 1-5 and the outer circumferential wall of the first sleeve 2 constitute an annular inner cavity, which is matched with the shape of the recessed groove 1-5 and is installed axially. The ring seat structure 5 is inserted, the mouth edge of the sink groove 1-5 and the inner peripheral wall of the cavity gland 1 form a step shape, the outer peripheral wall of the ring seat structure 5 is in a shape of large outer diameter at one end and small outer diameter at the other end, and a step-shaped transition in the middle. Through such a shape, the ring seat structure 5 and the mouth edge shape of the sink groove 1-5 of the cavity gland 1 form an axial abutment and limit fit, the ring seat structure 5 is installed with the first static ring 4 at one end facing the first dynamic ring 3, the end face of the first static ring 4 is fixed with the end face of the ring seat structure 5 through the third pin 9-3, and the other end face of the ring seat structure 5 is provided with a compression spring 6 that abuts against each other. The compression spring 6 is arranged axially, and the other end of the compression spring 6 abuts against the inner end face of the sink groove 1-5 in the axial direction. Therefore, the compression spring 6 can provide the ring seat structure 5 and the first static ring 4 fixed to the ring seat structure 5 with a movement tendency to move axially toward one end of the first dynamic ring 3, so that the first static ring 4 abuts against the end face of the first dynamic ring 3. Such a structure can obtain a good mechanical sealing effect.

[0032] In the technical solution provided in this embodiment, one axial end of the hollow cavity 1-4 of the cavity gland 1 is closed and the other end is open, and a gland cover plate 1-2 for closing the hollow cavity 1-4 is detachably installed at the open end. The design optimizes the structure of the cavity gland 1, and the cavity gland 1 is a structure in which one end is closed and the other end is open, and a gland cover plate 1-2 is provided to close the opening in accordance with the size and shape of the opening, and the gland cover plate 1-2 is detachably installed, which can be specifically implemented by means of screws 12 and the like. The design can conveniently inspect and replace the polymer filling block filled in the cavity gland 1, greatly reducing the difficulty of inspection and maintenance.

[0033] In the technical solution provided in this embodiment, the cavity cover 1 is provided with an annular sealing plate structure 1-3 on the outer side of the cover cover plate 1-2, and the annular sealing plate structure 1-3 is installed and fixed to the cavity cover 1 by screws 12; a positioning ring 7 is installed and fixed on the outer peripheral surface of the first sleeve 2, and the positioning ring 7 is abutted against the end face of the annular sealing plate structure 1-3 which is away from the cover cover plate 1-2, and is used for axial positioning of the cavity cover 1. This design optimizes the matching mode between the cavity pressure cover 1 and the first shaft sleeve 2, and sets an annular sealing plate structure 1-3 for the pressure cover cover plate 1-2. Through this design, the installation and fixing position of the pressure cover cover plate 1-2 can be stabilized, and it can be directly installed and fixed with the cavity pressure cover 1 by screws 12. A positioning ring 7 is sleeved at a corresponding position on the outer circumference of the first shaft sleeve 2, and the end face of the positioning ring 7 is abutted against the annular sealing plate structure 1-3 to axially position the cavity pressure cover 1. The installation positions of the positioning ring 7 and the screws 12 are located at different radial positions of the annular sealing plate structure 1-3 to ensure firm positioning; the positioning ring 7 is preferably installed with the shaft by a pin or screw structure, and can further adopt a through hole structure on the side wall, and the pin or screw used to fix the positioning ring 7 is directly passed through the through hole to be fixed to the shaft body in the first shaft sleeve 2, and the first shaft sleeve 2 can be axially positioned at the same time in this way.

[0034] In the technical solution provided in this embodiment, the cavity cover 1 is provided with an annular barrier sealing structure 8 between its two axial ends and the first sleeve 2. The barrier sealing structure 8 located at one end of the cover plate 1-2 is a lip seal, one of the sealing surfaces of the lip seal is in contact with the outer peripheral surface of the first sleeve 2, and the other sealing surface of the lip seal is in contact with the joint position of the annular sealing plate structure 1-3 and the cavity cover 1. This design optimizes the sealing and anti-leakage design of the overall axial ends of the sealing device. The key position of the seal is at the joint between the first sleeve 2 and the cavity cover 1. The barrier sealing structure 8 at one end of the cavity cover 1 is a lip seal. The two adjacent sealing end faces of the lip seal are respectively fitted with the outer peripheral surface of the first sleeve 2 and the inner end face of the annular sealing plate structure to achieve sealing, that is, the setting method of the lip seal is exactly opposite to its conventional placement direction; the barrier seal located at the closed end of the cavity cover 1 is a skeleton oil seal structure. In order to assist the installation of the oil seal structure, a retaining ring or an annular gasket-like structure is preferably provided on the side edge of the corresponding end of the cavity cover 1 to facilitate the cooperation between the end face and the oil seal structure.

[0035] In the technical solution provided in this embodiment, a raised first shoulder structure 10-1 is provided at a position adjacent to the lip seal on the outer circumference of the first sleeve 2. The first shoulder structure 10-1 is opposite to the axial position of the drainage structure 1-1. The first shoulder structure 10-1 blocks the axial leakage oil path on the outer circumference of the first sleeve 2, and introduces the leaked liquid into the drainage structure 1-1. This design optimizes the internal space within the blocking seal structure 8 at both ends, optimizes the surface structure of the first sleeve 2 in this space, and sets a first shoulder structure 10-1 with a suitable height to block the leakage oil path on the outer circumference of the first sleeve 2, so that the end face leakage medium can be effectively blocked, and the shaft surface oil is driven outward by the rotation of the shaft, and then the blocked oil is introduced into the cavity of the cavity gland 1 through the small hole groove or other forms of drainage structure 1-1, and locked by the polymer filling block.

[0036] refer to Figure 3 , Figure 4 The following embodiments are described, Figure 3 A schematic cross-sectional structure diagram of another leakage-free sealing device provided by the present invention; Figure 4 for Figure 3 A schematic diagram of the partially enlarged cross-section structure of a leak-free sealing device.

[0037] The present embodiment provides a technical solution with the same sealing design structure as that in the above-mentioned embodiment, wherein the mechanical seal inner seal assembly comprises a second sleeve 2-2, a second dynamic ring 3-2, a second stationary ring 4-2 and a stationary ring seat 5-2, the second sleeve 2-2 and the second dynamic ring 3-2 are both sleeved on the outer periphery of the shaft, a stepped annular slot is provided at one end of the cavity pressure cover 1, the stationary ring seat 5-2 is sleeved on the outer peripheral wall of the second sleeve 2-2 and inserted into the annular slot of the cavity pressure cover 1, an annular mounting groove is provided on one end face of the stationary ring seat 5-2, the outer peripheral wall of the second stationary ring 4-2 is interference fit with the inner peripheral wall of the mounting groove, a compression spring 6 is provided in the annular slot of the cavity pressure cover 1, and the compression spring 6 is axially arranged at both ends to respectively press against the cavity pressure cover 1 and the stationary ring seat 5-2, so as to provide elastic force to press the end faces of the second stationary ring 4-2 and the second dynamic ring 3-2 against each other.

[0038] This design provides another optional mechanical seal inner seal assembly, which is suitable for the working environment of aerospace. The specific structure is different from the technical solution of the above embodiment, but the principle used is the same. Specifically: The cavity gland 1 also has an annular main structure, and a closed cavity is formed between the inner wall side and the mechanical seal inner seal assembly, and drainage is performed through the drainage structure 1-1. The cavity gland 1 is adapted to the structure of the second stationary ring 4-2 and the stationary ring seat 5-2, and a stepped annular slot is arranged between its inner circumferential wall and the end face, and a transition structure between the inner circumferential wall and the end face is formed by the stepped structure.

[0039] The second sleeve 2-2 is sleeved on the outside of the shaft whose sealing is to be optimized, the second dynamic ring 3-2 is directly sleeved on the outer peripheral wall of the shaft, the second static ring 4-2 is sleeved on the outer peripheral wall of the second sleeve 2-2, and the end face of one end of the second dynamic ring 3-2 is abutted against the bearing outside the shaft, and the other end face thereof is abutted against the end face of the second sleeve 2-2 and the end face of the second static ring 4-2 at different radial positions at the same time.

[0040] The outer wall of the stationary ring seat 5-2 is shaped like an annular structure with a large radial dimension at one end and a small radial dimension at the other end. The end with a smaller radial dimension of the outer wall of the stationary ring seat 5-2 is inserted into the annular slot of the cavity pressure cover 1. The stationary ring seat 5-2 is provided with an annular mounting groove on the end face for docking with the second stationary ring 4-2, and the outer wall of the second stationary ring 4-2 is directly interference fit with the inner wall of the mounting groove without being fixed by pins.

[0041] In addition, it is preferred to set a sealing ring 14 on the axial surface that cooperates with each other between the inner circumferential wall of the cavity pressure cover 1 and the outer circumferential wall of the stationary ring seat 5-2 to form a good seal; an annular slot is set on the inner edge of the cavity pressure cover 1 that fits the second sleeve side, and the stationary ring seat 5-2 has a stepped structure, and its end with a smaller radial dimension is inserted into the slot, wherein an annular mounting groove is set at the end with a larger radial dimension, and the second stationary ring is inserted into the groove, and an axial limit is provided between the stationary ring seat 5-2 and the cavity pressure cover 1 through a retaining ring 11; the annular slot of the cavity pressure cover 1 is provided with a plurality of spring slots at preset intervals on the end face of one end facing the second stationary ring 4-2, so as to set a compression spring 6 to provide elastic force to make the second stationary ring 4-2 press against the second moving ring 3-2.

[0042] In the technical solution provided in this embodiment, a flow channel groove 13 for draining leakage is arranged between the inner circumference of the second stationary ring and the stationary ring seat 5-2 and the second sleeve 2-2, and a raised second shoulder structure 10-2 is arranged on the outer circumference of the second sleeve 2-2 at a position corresponding to the drainage structure 1-1 on the cavity pressure cover 1, which is used to block the oil path on the outer circumference of the second sleeve 2-2. The design further optimizes the leakage drainage design inside the inner sealing assembly of the mechanical seal, and optimizes the design of introducing the leaked liquid into the space inside the cavity pressure cover 1. The second stationary ring 4-2 and the stationary ring seat 5-2 are provided with a flow channel groove 13 at the inner edge position of the second sleeve for draining the oil. The flow channel groove 13 is provided with a raised second shoulder structure 10-2 on the trajectory extending from the outer peripheral surface of the second sleeve 2-2 and at the position corresponding to the drainage structure 1-1 of the cavity pressure cover 1 to block the leakage oil path on the second sleeve 2-2, so that the end face leakage medium can be effectively blocked and the oil is helped to enter the cavity in the cavity pressure cover 1 through the small holes of the drainage structure 1-1.

[0043] In the technical solution provided in this embodiment, the inner side wall of the hollow cavity 1-4 of the cavity gland 1 is integrally connected with a support rib or a support grid structure for enhancing the pressure bearing capacity of the cavity gland 1. This design further optimizes the internal structure of the cavity of the cavity gland 1, and the inner side wall of the hollow cavity 1-4 is provided with a support structure such as a support rib plate or a honeycomb-shaped, three-dimensional grid-shaped filling support structure in the cavity. Such a design is mainly to enhance the pressure bearing strength of the hollow thin-walled cavity gland 1 to avoid damage due to pressure, and the structure occupies as little volume of the polymer filling block in the cavity as possible.

[0044] Although the present invention is disclosed as above, the protection scope of the present invention is not limited thereto. Those skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention, and these changes and modifications will fall within the protection scope of the present invention.

Claims

1. A leak-free sealing device for sealing shaft structures, characterized in that: It comprises a mechanical seal inner seal component sleeved on the outer periphery of a shaft, the outer periphery of the mechanical seal inner seal component sleeved with a leakage absorption component, the leakage absorption component comprising a cavity gland (1) provided with a hollow cavity (1-4), the cavity gland (1) being annular, the inner peripheral wall of the cavity gland (1) being provided with a drainage structure (1-1) for connecting the hollow cavity (1-4) with the oil path of the mechanical seal inner seal component, and a polymer filling block for absorbing liquid being provided in the hollow cavity (1-4); The mechanical seal inner seal assembly comprises a first sleeve (2) and a first moving ring (3) and a first stationary ring (4) sleeved on the first sleeve (2); an annular protrusion (2-1) is provided on the outer peripheral wall of the first sleeve (2); the first moving ring (3) is mounted and fixed to the protrusion (2-1) via a first pin (9-1); the first stationary ring (4) is circumferentially positioned and connected to the inner peripheral wall of the cavity gland (1) and elastically cooperates with an axially arranged compression spring (6); the end faces of the first moving ring (3) and the first stationary ring (4) are abutted against each other by the elastic force provided by the compression spring (6); Or the mechanical seal inner seal assembly comprises a second sleeve (2-2), a second moving ring (3-2), a second stationary ring (4-2) and a stationary ring seat (5-2); the second sleeve (2-2) and the second moving ring (3-2) are both sleeved on the outer circumference of the shaft; one end of the cavity gland (1) is provided with a stepped annular slot; the stationary ring seat (5-2) is sleeved on the outer circumferential wall of the second sleeve (2-2) and inserted into the annular slot of the cavity gland (1); one end surface of the stationary ring seat (5-2) is provided with an annular mounting groove; the outer circumferential wall of the second stationary ring (4-2) is interference-fitted with the inner circumferential wall of the mounting groove; a compression spring (6) is provided in the annular slot of the cavity gland (1); the compression spring (6) is arranged along the axial direction and its two ends are respectively pressed against the cavity gland (1) and the stationary ring seat (5-2) for providing elastic force to press the end faces of the second stationary ring (4-2) and the second moving ring (3-2) against each other.

2. The leak-free sealing device according to claim 1, characterized in that: When the mechanical seal inner seal assembly comprises a first sleeve (2) and a first dynamic ring (3) and a first static ring (4) sleeved on the first sleeve (2), an inner peripheral wall of the cavity gland (1) is provided with an annular recessed groove (1-5), an annular ring seat structure (5) is provided in the recessed groove (1-5), the ring seat structure (5) is circumferentially positioned and matched with the cavity gland (1) via a second pin (9-2), the two ends of the compression spring (6) are respectively abutted against the end surface of the ring seat structure (5) and the recessed groove (1-5), and the first static ring (4) is fixedly mounted on the end surface of the ring seat structure (5) on the side away from the compression spring (6) via a third pin (9-3).

3. The leak-free sealing device according to claim 2, characterized in that: One axial end of the hollow cavity (1-4) is closed and the other end is open, and a gland cover plate (1-2) for closing the hollow cavity (1-4) is detachably mounted on the open end of the hollow cavity (1-4).

4. The leak-free sealing device according to claim 3, characterized in that: The cavity gland (1) is provided with an annular sealing plate structure (1-3) on the outer side of the gland cover plate (1-2), and the annular sealing plate structure (1-3) is mounted and fixed to the cavity gland (1) by means of screws (12); a positioning ring (7) is mounted and fixed to the outer peripheral surface of the first shaft sleeve (2), and an end surface on one side of the annular sealing plate structure (1-3) that faces away from the gland cover plate (1-2) abuts against the positioning ring (7), and the positioning ring (7) is used for axial positioning of the cavity gland (1).

5. The leak-free sealing device according to claim 4, characterized in that: The cavity gland (1) is provided with an annular barrier sealing structure (8) between its two axial ends and the first shaft sleeve (2); the barrier sealing structure (8) located at one end of the gland cover plate (1-2) is a lip seal, one sealing surface of the lip seal is in contact with the outer peripheral surface of the first shaft sleeve (2), and the other sealing surface of the lip seal is in contact with the gap between the cavity gland (1) and the annular sealing plate structure (1-3).

6. The leak-free sealing device according to claim 5, characterized in that: A raised first shaft shoulder structure (10-1) is provided at a position adjacent to the lip seal on the outer peripheral surface of the first shaft sleeve (2); the first shaft shoulder structure (10-1) is located opposite to the drainage structure (1-1); and the leaked liquid is introduced into the drainage structure (1-1) by blocking the oil path on the outer peripheral surface of the first shaft sleeve (2) through the first shaft shoulder structure (10-1).

7. The leak-free sealing device according to claim 1, characterized in that: When the mechanical seal inner seal assembly comprises a second shaft sleeve (2-2), a second dynamic ring (3-2), a second stationary ring (4-2) and a stationary ring seat (5-2), a flow channel groove (13) for draining leakage is provided between the inner circumference of each of the second stationary ring (4-2) and the stationary ring seat (5-2) and the second shaft sleeve (2-2), and a protruding second shaft shoulder structure (10-2) is provided on the outer circumference of the second shaft sleeve (2-2) at a position corresponding to the drainage structure (1-1) on the cavity gland (1), so as to block the oil path on the outer circumference of the second shaft sleeve (2-2).

8. The leak-free sealing device according to claim 1, characterized in that: The inner side wall of the hollow cavity (1-4) of the cavity gland (1) is integrally connected with a support rib or a support grid structure for enhancing the pressure bearing capacity of the cavity gland (1).

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