A high-pressure-resistant assembled mechanical seal

Abstract

The present invention provides a high-pressure-resistant integrated mechanical seal, which includes a first shaft sleeve, a second shaft sleeve, a first gland and a second gland. A main seal is installed between one end of the first gland away from the second gland and one end of the first shaft sleeve, and a first sealing cavity is formed inside the main seal; a secondary seal is installed between one end of the second gland close to the first gland and a second mounting boss of the second shaft sleeve close to the first shaft sleeve, and a second sealing cavity is formed inside the secondary seal; a liquid inlet hole and a liquid outlet hole are provided on the outer side wall of the first gland, and a cooling cavity is provided between the inner wall of the first shaft sleeve and the outer wall of the rotating shaft. Both ends of the cooling cavity are communicated with the first sealing cavity and the second sealing cavity respectively; a skeleton oil seal is installed at the bottom inside the first mounting groove for axially blocking the first sealing cavity and the second sealing cavity. The high-pressure-resistant integrated mechanical seal disclosed by the present invention realizes local cooling of the rotating shaft without destroying the original flushing and cooling functions, and ensures the high-pressure-resistant performance of the mechanical seal.

Description

Technical Field

[0001] The present invention relates to the technical field of mechanical seals, and more particularly, to a high-pressure-resistant assembled mechanical seal. Background Art

[0002] A mechanical seal is a shaft seal device for a rotating machine. Since the rotating shaft penetrates inside and outside the equipment, there is a circumferential gap between the shaft and the equipment. The medium in the equipment leaks out through this gap. If the pressure inside the equipment is lower than the atmospheric pressure, air leaks into the equipment. Therefore, a shaft seal device to prevent leakage is necessary. There are many types of shaft seals. Due to the advantages of less leakage and long service life of mechanical seals, mechanical seals are the most important shaft seal method in these equipment.

[0003] In the existing double-ended surface assembled mechanical seal device, in order to improve the sealing performance of the sealing surface, an isolation cavity, also called a sealing cavity, is usually provided between the inner wall of the sealing component and the outer wall of the shaft sleeve, and an isolation liquid is introduced into the sealing cavity to cool the sealing surface. However, in a high-pressure environment, due to the increase in pressure, a large amount of frictional heat of the sealing surface will increase, and part of the heat will be transferred to the rotating shaft through the shaft sleeve. If there is too much concentrated heat at a certain position on the rotating shaft, it is easy to cause deformation of the rotating shaft itself, thus affecting normal operation. In the existing sealing structure, due to the limitation of space, it is difficult to design an additional heat dissipation channel for the rotating shaft, and the processing cost is high. Therefore, it is very necessary to develop a structure that can make full use of the existing sealing cavity structure to increase the local cooling performance of the rotating shaft without affecting the normal heat dissipation of the sealing surface. Summary of the Invention

[0004] The problem solved by the present invention is to overcome at least one defect in the prior art, and provide a high-pressure-resistant assembled mechanical seal that makes full use of the existing isolation cavity structure to achieve local cooling of the rotating shaft without destroying the original flushing and cooling function, ensuring that the mechanical seal and the rotating shaft can operate well in a high-pressure environment and have a long service life.

[0005] To solve the above problems, the present invention provides a high-pressure-resistant assembled mechanical seal, which includes a first shaft sleeve and a second shaft sleeve that are axially connected and have different diameters. A first gland is sleeved outside the first shaft sleeve, and a second gland is sleeved outside the second shaft sleeve, and the second gland axially abuts against the first gland; a first mounting boss is provided at one end of the first shaft sleeve away from the second gland, and a first mounting groove is provided on the inner side of the first gland near the first mounting boss. A main seal is assembled between the first mounting boss and the first mounting groove, and a first sealing cavity is formed between the inner wall of the main seal and the outer wall of the first shaft sleeve; the diameter of the first shaft sleeve is larger than that of the second shaft sleeve, so that a second mounting boss is formed at one end of the first shaft sleeve near the second shaft sleeve, and a second mounting groove is provided on the inner side of the second gland near the first gland. A secondary seal is assembled between the second mounting boss and the second mounting groove, and a second sealing cavity is formed between the outer wall of the secondary seal and the inner wall of the second mounting groove and the end face of the first gland; a liquid inlet hole communicating with the first sealing cavity is provided on the outer side wall of the first gland, a cooling cavity is provided between the inner wall of the first shaft sleeve and the outer wall of the rotating shaft, one end of the cooling cavity near the first mounting boss communicates with the first sealing cavity, the other end of the cooling cavity communicates with the second sealing cavity, and a liquid outlet hole communicating with the second sealing cavity is provided on the outer side wall of the second gland; a skeleton oil seal is assembled at the bottom inside the first mounting groove, and the inner ring of the skeleton oil seal is slidably and sealingly assembled on the outer wall of the first shaft sleeve, so that the flushing liquid entering from the liquid inlet hole passes through the first sealing cavity, the cooling cavity, and the second sealing cavity in sequence and then flows out from the liquid outlet hole.

[0006] Compared with the prior art, the present invention has the following advantages:

[0007] In the mechanical seal structure of the present invention, the shaft sleeve is set into a two-stage structure with different diameters, and the installation and positioning of the secondary seal can be realized without adding additional structures; in addition, through the setting of the skeleton oil seal, the axial blockage between the first sealing cavity and the second sealing cavity is carried out, and a corresponding cooling cavity is provided between the inner wall of the first shaft sleeve and the outer wall of the rotating shaft. Since the main seal is sleeved outside the first shaft sleeve and needs to bear higher pressure, it generates more heat. After the cooling cavity is set, the coolant in the first sealing cavity can flow through the rotating shaft at the same time to locally cool it; and the water inlet of the cooling cavity is located near the main seal. In this way, after the coolant entering from the liquid inlet hole enters the first sealing cavity, it first quickly passes through the main seal surface position for cooling, then enters the cooling cavity, and finally enters the second sealing cavity and flows out from the liquid outlet hole. The overall structure is reasonable, without complex structures, and the processing and installation are also very convenient, effectively solving the problem of local high temperature of the rotating shaft.

[0008] As an improvement, the main seal includes a driving ring, a main static ring assembly and a fixing seat. One end of the first mounting boss near the first gland is provided with a moving ring groove, and one end of the driving ring is fitted in the moving ring groove; one end of the fixing seat is fitted at the bottom of the first mounting groove, and a positioning shaft is provided in the middle of the other end of the fixing seat, so that a positioning boss is formed on the radial outer part of the end of the fixing seat away from the first mounting groove. One end of the main static ring assembly is slidably fitted on the positioning shaft, and a first elastic compensation element is provided between the end of the main static ring assembly and the positioning boss. The other end of the main static ring assembly and the other end of the driving ring are in rotatable contact with each other; multiple grooves distributed circumferentially are provided at one end of the fixing seat near the first mounting groove, and each groove communicates with the liquid inlet hole. A gap is left between the inner wall of the fixing seat and the outer wall of the first shaft sleeve. In the above improved structure, a static ring compensation structure is adopted in the main seal, and the compensation performance can be ensured to be stable even in a high-pressure environment. In addition, a fixing seat is arranged in the first mounting groove, and the main static ring assembly is in sliding fit with the fixing seat. Multiple grooves are formed at the tail end of the fixing seat for more uniform entry of the coolant into the first sealing cavity to ensure the cooling effect. Moreover, the fixing seat and the first gland are of a split structure, which is convenient for processing.

[0009] As a further improvement, a flushing cavity is provided between the outer wall of the main seal and the inner wall of the first mounting groove. A flushing hole communicating with the flushing cavity is further provided on the outer side wall of the first gland, and the flushing hole corresponds to the position of the first elastic compensation element. In the above improved structure, the flushing hole is provided for timely flushing of the first elastic compensation element to prevent blockage of the elastic element; in addition, the outlet end of the flushing liquid in the flushing hole can also flush the outer end face of the main seal to prevent accumulation of impurity particles at the main seal surface.

[0010] As a further improvement, the main static ring assembly includes a main static ring, a first static ring seat and a second static ring seat. One end of the second static ring seat is slidably fitted outside the positioning shaft, and a gap is left between the inner wall of the second static ring and the outer wall of the shaft sleeve; one end of the first static ring seat is sleeved outside the other end of the second static ring seat, and a limiting ring bent inward is provided at the other end of the first static ring seat. One end of the main static ring abuts against the second static ring seat, and the limiting ring presses against the other end of the main static ring.

[0011] Further improved, a plurality of connecting bolts evenly distributed in the circumferential direction are provided on the outer side wall of the first stationary ring seat, and positioning holes for inserting and fitting the screw rods of the connecting bolts are provided on the outer side wall of the second stationary ring seat; a plurality of positioning sliding grooves extending along the axial direction are provided on the side wall of the first installation groove, and the bolt heads of the connecting bolts are respectively slidably fitted in the corresponding positioning sliding grooves. In the above improved structure, without adding other components, the connecting bolt structure not only plays a role in connecting the first stationary ring seat and the second stationary ring seat, but also can realize the circumferential anti-rotation of the main stationary ring assembly, with a simple and reasonable structure, few components and low cost.

[0012] Further improved, a first sealing ring is provided between the driving ring and the first installation boss, a second sealing ring is provided between the main stationary ring and the second stationary ring seat, and a third sealing ring is provided between the second stationary ring seat and the positioning shaft. The first sealing ring, the second sealing ring and the third sealing ring are located on the same horizontal line. In the above improved structure, the three sealing rings are located on the same horizontal line, and no torque will be generated during operation, which can better balance the pressure, so that a higher pressure can be withstood, ensuring the stability of the seal.

[0013] Further improved, the auxiliary seal includes an auxiliary driving ring assembly and an auxiliary stationary ring assembly. The auxiliary driving ring assembly includes an auxiliary driving ring and an auxiliary driving ring seat. The auxiliary driving ring is sleeved outside the second shaft sleeve and one end of the auxiliary driving ring abuts against the second installation boss; one end of the auxiliary driving ring seat is sleeved outside the first shaft sleeve, and the other end of the auxiliary driving ring seat is sleeved outside the auxiliary driving ring. In the above improved structure, the installation structure of the auxiliary driving ring is simple and convenient, and the outer circumference is limited by sleeving an auxiliary driving ring seat, ensuring the stability of the installation structure of the auxiliary driving ring.

[0014] Further improved, the auxiliary stationary ring assembly includes an auxiliary stationary ring and an auxiliary stationary ring seat. One end of the auxiliary stationary ring seat is slidably fitted at the bottom inside the second installation groove. An auxiliary stationary ring groove is provided inside the other end of the auxiliary stationary ring seat. A support ring is fitted inside the auxiliary stationary ring groove. One end of the auxiliary stationary ring is fitted in the installation channel between the inner wall of the auxiliary stationary ring groove and the outer wall of the support ring. The other end of the auxiliary stationary ring abuts against the other end of the auxiliary driving ring in a relatively rotatable manner; a second elastic compensation element is provided between the auxiliary stationary ring seat and the bottom of the second installation groove. In the above improved structure, a stationary ring compensation structure is adopted in the auxiliary seal to ensure stable compensation performance under high-pressure environments; in addition, the inner side of the auxiliary stationary ring is supported by adding a support ring, enabling it to withstand higher pressures without deformation.

[0015] Further improved, the first bushing, the second bushing and the first mounting boss are of an integral structure; an annular inner groove is provided on the inner wall of the first bushing, and a plurality of first through holes and second through holes distributed circumferentially are respectively formed on the side walls at both ends of the first bushing. The plurality of first through holes communicate with one end of the inner groove near the first mounting boss, and the plurality of second through holes communicate with the other end of the inner groove. In the above improved structure, preferably, the first bushing and the second bushing are of an integral structure, and the cooling cavity is formed by providing a corresponding inner groove on the inner wall of the first bushing, with a simple structure and convenient processing. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 FIG. is a schematic structural diagram of the high-pressure-resistant assembled mechanical seal of the present invention installed on a rotating shaft;

[0017] Figure 2 FIG. is a partial cross-sectional view of the main static ring assembly of the present invention installed on the first gland;

[0018] Figure 3 is Figure 1 the enlarged structure diagram at X in

[0019] DESCRIPTION OF THE REFERENCE NUMERALS:

[0020] 1. First bushing; 1.1 Inner groove; 1.2 First through hole; 1.3 Second through hole; 2. Second bushing; 2.1 Annular positioning groove; 3. First gland; 3.1 First mounting groove; 3.1.1 Positioning sliding groove; 3.2 Liquid inlet hole; 3.3 Flushing hole; 4. Second gland; 4.1 Second mounting groove; 4.1.1 Second spring hole; 4.2 Liquid outlet hole; 5. First mounting boss; 5.1 Moving ring groove; 6. First sealing cavity; 7. Second mounting boss; 8. Second sealing cavity; 9. Cooling cavity; 10. Skeleton oil seal; 11. Driving ring; 12. Fixed seat; 13. Positioning shaft; 14. Positioning boss; 14.1 First spring hole; 15. Main static ring; 16. First static ring seat; 17. Second static ring seat; 17.1 Positioning hole; 18. Limiting ring; 19. Connecting bolt; 20. First sealing ring; 21. Second sealing ring; 22. Third sealing ring; 23. Auxiliary driving ring; 24. Auxiliary driving ring seat; 25. Auxiliary static ring; 26. Auxiliary static ring seat; 26.1 Fitting shaft; 26.2 Auxiliary static ring groove; 27. Support ring; 28. Flushing cavity; 29. Limiting block; 30. Driving disc assembly; 31. Fastening ring; 32. First spring; 33. Second spring. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0021] In order to make the above objects, features and advantages of the present invention more obvious and understandable, the specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0022] In the description of the present invention, it should be noted that the orientation or positional relationship indicated by terms such as "outer", "tail end", "outer side", "inner wall", "bottom", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation to the present invention. Additionally, in the description terms "first" and "second" are only for the convenience of distinction and understanding, without specific special or defined meanings. Among them, the tail end refers to the end away from the friction surface. For example, the tail end of the moving ring refers to the end of the moving ring away from the grinding surface.

[0023] In the description of the present invention, it should be noted that unless otherwise clearly specified and limited, the term "connection" 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 directly connected, or indirectly connected through an intermediate medium, and can be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0024] Such as Figure 1As shown in the figure, the present invention provides a high-pressure resistant assembled mechanical seal, which includes a first shaft sleeve 1 and a second shaft sleeve 2 that are axially connected and have different diameters. A first gland 3 is sleeved outside the first shaft sleeve 1, and a second gland 4 is sleeved outside the second shaft sleeve 2. The second gland 4 is axially abutted against the first gland 3. Specifically, the first gland 3 and the second gland 4 are axially connected and fixed by a plurality of connecting bolts 19 (not shown in the figure), and corresponding O-rings are installed between the abutting surfaces. In addition, one end of the first shaft sleeve 1 away from the second gland 4 is provided with a first mounting boss 5. The inner side of the first gland 3 near the first mounting boss 5 is provided with a first mounting groove 3.1. A main seal is installed between the first mounting boss 5 and the first mounting groove 3.1, and a first sealing cavity 6 is formed between the inner wall of the main seal and the outer wall of the first shaft sleeve 1. On the other hand, the diameter of the first shaft sleeve 1 is larger than that of the second shaft sleeve 2, so that a second mounting boss 7 is formed at one end of the first shaft sleeve 1 close to the second shaft sleeve 2. The inner side of the second gland 4 near the first gland 3 is provided with a second mounting groove 4.1. A secondary seal is installed between the second mounting boss 7 and the second mounting groove 4.1 and on the outer wall of the shaft sleeve. A second sealing cavity 8 is formed between the outer wall of the secondary seal and the inner wall of the second mounting groove 4.1 and the end face of the first gland 3. A liquid inlet hole 3.2 communicating with the first sealing cavity 6 is provided on the outer side wall of the first gland 3. A cooling cavity 9 is provided between the inner wall of the first shaft sleeve 1 and the outer wall of the rotating shaft. One end of the cooling cavity 9 near the first mounting boss 5 is communicated with the first sealing cavity 6, and the other end of the cooling cavity 9 is communicated with the second sealing cavity 8. A liquid outlet hole 4.2 communicating with the second sealing cavity 8 is provided on the outer side wall of the second gland 4. A skeleton oil seal 10 is installed at the bottom of the inner side of the first mounting groove 3.1. The inner ring of the skeleton oil seal 10 is slidably and sealingly installed on the outer wall of the first shaft sleeve 1, so that the flushing liquid entering from the liquid inlet hole 3.2 flows out from the liquid outlet hole 4.2 after passing through the first sealing cavity 6, the cooling cavity 9, and the second sealing cavity 8 in sequence. In addition, in the above structure, in order to better realize the integral disassembly and assembly of the mechanical seal, a plurality of limiting blocks 29 distributed along the circumferential direction are provided on the side wall of the second gland 4 away from the first gland 3, and corresponding annular positioning grooves 2.1 are provided on the outer wall of the second shaft sleeve 2. The inner ends of the respective limiting blocks 29 are respectively detachably inserted and fitted in the annular positioning grooves 2.1. It should be noted here that the limiting blocks 29 actually play a role during the pre-assembly of the product, facilitating the overall installation. Of course, when the mechanical seal needs to be disassembled, the limiting blocks 29 can be installed again to facilitate the overall disassembly.

[0025] In this embodiment, as a preference, the first sleeve 1, the second sleeve 2 and the first mounting boss 5 are an integrated structure; and an annular inner groove is provided on the inner wall of the first sleeve 1, and a plurality of first through holes 1.2 and second through holes 1.3 distributed along the circumferential direction are respectively opened on the side walls at both ends of the first sleeve 1, and the plurality of first through holes 1.2 are connected to one end of the inner groove near the first mounting boss 5, and the plurality of second through holes 1.3 are connected to the other end of the inner groove. In the above structure, the first sealing member 1 is provided with the cooling chamber 9 and the axial blocking setting of the skeleton oil seal 10. The cooling water in the cavity 6 can cool the rotating shaft synchronously, and directly enters the cooling cavity 9 from the first sealing cavity 6, first cools the rotating shaft, and then enters the second sealing cavity 8, so as to better ensure the cooling of the first sleeve 1 and the rotating shaft. Because the sealing grinding surface is prone to generate higher heat in a high-pressure environment, excessive heat is transferred to the rotating shaft, which is easy to cause the rotating shaft to deform and even affect the operating performance of the rotating shaft. In this embodiment, effective improvements are made to achieve flushing cooling of the main seal and the auxiliary seal, and synchronous cooling of the rotating shaft. The specific cooling water flow direction is as follows: Figure 1 Indicated by the direction of the arrow.

[0026] On the other hand, when the whole set of assembled mechanical seals is installed on the rotating shaft, it is necessary to clamp and drive them. In this embodiment, a drive disc assembly 30 is mounted on the outside of the second sleeve 2 away from the second pressure cover 4. The drive disc in this embodiment is improved on the basis of the existing technology. The improved main structure includes an upper pressure plate, a lower pressure plate and an intermediate retaining ring. For details, please refer to the drive disc assembly 30 disclosed in patent CN1111211281136A. In this embodiment, on the basis of the existing drive disc assembly 30, a fastening ring 31 is added to its outer side, and symmetrical inclined surfaces are set on the radial outer side walls of the upper pressure plate and the lower pressure plate to form a V-shaped groove. The corresponding inner hole wall shape of the fastening ring 31 matches the V-shaped groove. The fastening ring 31 is set so that the upper pressure plate and the lower pressure plate have a certain limiting effect in the radial direction when they are relatively close to each other, so as to avoid deformation under the expansion effect of the inclined guide surface of the intermediate retaining ring. The mechanical seal in this embodiment is used in a high-pressure environment, and the axial force acting on the shaft sleeve will be correspondingly increased compared with the conventional one, so a fastening ring 31 with a certain thickness is added on the basis of the existing structure.

[0027] More specifically, Figure 1 , 2As shown in the figure, the main seal includes a driving ring 11, a main static ring 15 assembly and a fixing seat 12. One end of the first mounting boss 5 near the first gland 3 is provided with a moving ring groove 5.1, and one end of the driving ring 11 is fitted in the moving ring groove 5.1. One end of the fixing seat 12 is fitted at the bottom of the first mounting groove 3.1. The middle of the other end of the fixing seat 12 is provided with a positioning shaft 13, so that a positioning boss 14 is formed on the radial outer part of the end of the fixing seat 12 away from the first mounting groove 3.1. One end of the main static ring 15 assembly is slidably fitted on the positioning shaft 13, and a first elastic compensation element is provided between the end of the main static ring 15 assembly and the positioning boss 14. The other end of the main static ring 15 assembly is in rotatable contact with the other end of the driving ring 11 to form a main seal rubbing surface. Additionally, at one end of the fixing seat 12 near the first mounting groove 3.1, a plurality of circumferentially distributed grooves 12.1 are provided. Each groove 12.1 communicates with the liquid inlet hole 3.2, and a gap is left between the inner wall of the fixing seat 12 and the outer wall of the second shaft sleeve 2. After the structure of the plurality of grooves 12.1 is set in this structure, the flushing liquid entering from the liquid inlet hole 3.2 can be more evenly distributed into the aforementioned gap, and then flow to the position where the main seal surface is located, cooling and dissipating heat from it. At the same time, it can also take away the particulate matter at the seal rubbing surface, reduce the wear of the seal surface, and improve the service life of the mechanical seal.

[0028] Additionally, in this structure, the first elastic compensation element includes a plurality of first springs 32. A plurality of first spring holes 14.1 evenly distributed in the circumferential direction are provided on the positioning boss 14. One end of each first spring 32 is fitted in the first spring hole 14.1, and the end of each first spring 32 located in the first spring hole 14.1 abuts against the bottom of the first spring hole 14.1. The other end of each first spring 32 abuts against the tail end of the main static ring 15 assembly. The use of a plurality of first springs 32 provides axial compensation for the wear of the friction pair of the main seal surface, with a simple structure, uniform and stable compensation force.

[0029] More specifically, in the above structure, since each first spring 32 is directly in contact with the medium, in order to prevent impurities in the medium from accumulating in the gaps of the first springs 32 and affecting their elastic force, a flushing cavity 28 is provided between the outer wall of the main seal and the inner wall of the first mounting groove 3.1. A flushing hole 3.3 communicating with the flushing cavity 28 is also provided on the outer side wall of the first gland 3, and the flushing hole 3.3 corresponds to the first elastic compensation element. That is, by introducing flushing liquid into the flushing hole 3.3, effective flushing of the first springs 32 can be achieved, which can not only prevent the first springs 32 from being blocked, but also take away a part of the main seal friction heat. Additionally, the flushing liquid flowing out of the flushing cavity 28 can also achieve flushing of the outer end of the main seal surface in the radial direction, which can not only cool down, but also prevent particulate matter in the medium from accumulating at the seal surface, reduce the wear of the seal surface, and further improve the service life, as Figure 1 shown.

[0030] More specifically, asFigure 2 As shown, the main static ring 15 assembly in the above structure includes a main static ring 15, a first static ring seat 16, and a second static ring seat 17. One end of the second static ring seat 17 is slidably fitted outside the positioning shaft 13, and there is a gap between the inner wall of the second static ring and the outer wall of the shaft sleeve. One end of the first static ring seat 16 is sleeved outside the other end of the second static ring seat 17. The other end of the first static ring seat 16 is provided with a limiting ring 18 bent inward. One end of the main static ring 15 abuts against the second static ring seat 17, and the limiting ring 18 presses against the other end of the main static ring 15. Here, the main static ring 15 seat for installing the main static ring 15 is divided into two parts for separate processing, reducing the processing difficulty. More importantly, in this embodiment, at the bottom of the main static ring 15 seat, that is, one end of the end face of the second static ring seat 17 that abuts against the main static ring 15 needs to be ground. Of course, one end of the main static ring 15 close to the second static ring seat 17 also needs to be ground, so as to ensure that the main static ring 15 assembly can better adapt to the high-pressure environment.

[0031] On the other hand, in the above structure, a plurality of connecting bolts 19 evenly distributed in the circumferential direction are provided on the outer side wall of the first static ring seat 16, and positioning holes 17.1 for inserting and mating the screw rods of the respective connecting bolts 19 are provided on the outer side wall of the second static ring seat 17. Correspondingly, a plurality of positioning chutes 3.1.1 extending along its axial direction are provided on the side wall of the first installation groove 3.1, and the bolt heads of the respective connecting bolts 19 are respectively slidably fitted in the corresponding positioning chutes 3.1.1, so as to circumferentially limit the axial movement of the main static ring 15 assembly and prevent circumferential rotation.

[0032] In addition, as Figure 1 shown, a first sealing ring 20 is provided between the driving ring 11 and the first installation boss 5, a second sealing ring 21 is provided between the main static ring 15 and the second static ring seat 17, and a third sealing ring 22 is provided between the second static ring seat 17 and the positioning shaft 13. The first sealing ring 20, the second sealing ring 21, and the third sealing ring 22 are located on the same horizontal line, and no torque will be generated, so that higher pressures can be withstood. In this embodiment, the first sealing cavity 6 can withstand a maximum pressure of 115 MPA, and the main sealing part can withstand a maximum pressure of 30 MPA.

[0033] As Figure 3As shown in the figure, the secondary seal includes a secondary dynamic ring assembly and a secondary static ring assembly. The secondary dynamic ring assembly includes a secondary dynamic ring 23 and a secondary dynamic ring seat 24. The secondary dynamic ring 23 is sleeved outside the second shaft sleeve 2, and one end of the secondary dynamic ring 23 abuts against the second mounting boss 7. One end of the secondary dynamic ring seat 24 is sleeved outside the first shaft sleeve 1, and the other end of the secondary dynamic ring seat 24 is sleeved outside the secondary dynamic ring 23. More specifically, in this structure, corresponding limiting steps are provided on the inner hole wall of the secondary dynamic ring seat 24 for axially limiting the installation position of the secondary dynamic ring seat 24, and O-rings are installed between the outer side wall of the secondary dynamic ring seat 24 and the first shaft sleeve 1 and between the outer side wall of the secondary dynamic ring seat 24 and the secondary dynamic ring 23 respectively.

[0034] In addition, the secondary static ring assembly includes a secondary static ring 25 and a secondary static ring seat 26. One end of the secondary static ring seat 26 is slidably installed at the bottom inside the second installation groove 4.1. Specifically, a corresponding installation shaft 26.1 is provided on the radial inner side of the secondary static ring seat 26 away from the secondary dynamic end, and an installation hole for slidably mating with the installation shaft 26.1 is also provided at the bottom inside the second installation groove 4.1. A secondary static ring groove 26.2 is provided on the inner side of the other end of the secondary static ring seat 26, and a support ring 27 is installed inside the secondary static ring groove 26.2. One end of the secondary static ring 25 is installed in the installation channel between the inner wall of the secondary static ring groove 26.2 and the outer wall of the support ring 27. In this embodiment, the secondary dynamic ring 23 is made of a graphite ring, and the strength performance of the graphite material is weak. Therefore, the setting of the limiting ring 18 under high pressure can effectively prevent the secondary dynamic ring 23 from deforming inward, thereby improving the high-pressure resistance performance of the mechanical seal. The other end of the secondary static ring 25 abuts against the other end of the secondary dynamic ring 23 in a relatively rotatable manner to form a secondary seal friction surface. A second elastic compensation element is provided between the secondary static ring seat 26 and the bottom of the second installation groove 4.1. Similarly, the second elastic compensation element here includes a plurality of second springs 33. A plurality of second spring holes 4.1.1 are provided at the bottom of the second installation groove 4.1 and are evenly distributed along the circumferential direction. One end of each second spring 33 is installed in the second spring hole 4.1.1, and the end of each second spring 33 located in the second spring hole 4.1.1 abuts against the bottom of the second spring hole 4.1.1. The other end of each second spring abuts against the tail end of the secondary static ring seat 26. The use of a plurality of second springs 33 can axially compensate for the wear of the secondary seal surface, with a simple structure and stable compensation performance.

[0035] On the other hand, as Figure 2 、 3As shown, in this embodiment, coatings are provided on the outer wall of the positioning shaft 13 and the outer wall of the mating shaft 26.1, and O-rings are provided between the outer wall of the positioning shaft 13 and the mating hole of the second stationary ring seat 17, and between the outer wall of the mating shaft 26.1 and the inner wall of the mating hole. The coating structure can effectively reduce the risk of leakage caused by excessive wear of the O-ring on the outer wall of the positioning shaft 13 or the mating shaft 26.1 under high-pressure environment. In this embodiment, the fixed seat 12 is set to be a split structure with the first gland 3, so that the groove 12.1 structure is convenient to process and can better add a wear-resistant coating on the outer wall of the positioning shaft 13.

[0036] Although the present disclosure is disclosed as above, the protection scope of the present disclosure 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 disclosure, and these changes and modifications will all fall within the protection scope of the present invention.

Claims

1. A high-pressure-resistant assembled mechanical seal, characterized in that: it includes a first shaft sleeve (1) and a second shaft sleeve (2) that are axially connected and have different diameters. A first gland (3) is sleeved outside the first shaft sleeve (1), and a second gland (4) is sleeved outside the second shaft sleeve (2), and the second gland (4) axially abuts against the first gland (3); one end of the first shaft sleeve (1) away from the second gland (4) is provided with a first mounting boss (5), and a first mounting groove (3.1) is provided on the inner side of the first gland (3) near the first mounting boss (5). A main seal is assembled between the first mounting boss (5) and the first mounting groove (3.1), and a first sealing cavity (6) is formed between the inner wall of the main seal and the outer wall of the first shaft sleeve (1); the diameter of the first shaft sleeve (1) is larger than the diameter of the second shaft sleeve (2), so that a second mounting boss (7) is formed at one end of the first shaft sleeve (1) near the second shaft sleeve (2). A second mounting groove (4.1) is provided on the inner side of the second gland (4) near the first gland (3). A secondary seal is assembled between the second mounting boss (7) and the second mounting groove (4.1). A second sealing cavity (8) is formed between the outer wall of the secondary seal and the inner wall of the second mounting groove (4.1) and the end face of the first gland (3); a liquid inlet hole (3.2) communicating with the first sealing cavity (6) is provided on the outer side wall of the first gland (3). A cooling cavity (9) is provided between the inner wall of the first shaft sleeve (1) and the outer wall of the rotating shaft. One end of the cooling cavity (9) near the first mounting boss (5) is communicated with the first sealing cavity (6), and the other end of the cooling cavity (9) is communicated with the second sealing cavity (8). A liquid outlet hole (4.2) communicating with the second sealing cavity (8) is provided on the outer side wall of the second gland (4); a skeleton oil seal (10) is assembled at the bottom inside the first mounting groove (3.1), and the inner ring of the skeleton oil seal (10) is slidably and sealingly assembled on the outer wall of the first shaft sleeve (1), so that the flushing liquid entering from the liquid inlet hole (3.2) passes through the first sealing cavity (6), the cooling cavity (9), and the second sealing cavity (8) in sequence and then flows out from the liquid outlet hole (4.2).

2. The high-pressure-resistant assembled mechanical seal according to claim 1, characterized in that: The main seal includes a driving ring (11), a main static ring assembly, and a fixing seat (12). One end of the first mounting boss (5) near the first gland (3) is provided with a moving ring groove (5.1), and one end of the driving ring (11) is fitted in the moving ring groove (5.1); one end of the fixing seat (12) is fitted at the bottom of the first mounting groove (3.1), and a positioning shaft (13) is provided in the middle of the other end of the fixing seat (12), so that a positioning boss (14) is formed on the radial outer part of the end of the fixing seat (12) away from the first mounting groove (3.1). One end of the main static ring assembly is slidably fitted on the positioning shaft (13), and a first elastic compensation element is provided between the end of the main static ring assembly and the positioning boss (14). The other end of the main static ring assembly is in rotatable contact with the other end of the driving ring (11); near the end of the fixing seat (12) close to the first mounting groove (3.1), a plurality of circumferentially distributed grooves are provided, and each groove communicates with the liquid inlet hole (3.2), and a gap is left between the inner wall of the fixing seat (12) and the outer wall of the first shaft sleeve (1).

3. The high-pressure-resistant integrated mechanical seal according to claim 2, characterized in that: a flushing chamber (28) is provided between the outer wall of the main seal and the inner wall of the first mounting groove (3.1), a flushing hole (3.3) communicating with the flushing chamber (28) is further provided on the outer side wall of the first gland (3), and the flushing hole (3.3) corresponds to the position of the first elastic compensation element.

4. The high-pressure-resistant integrated mechanical seal according to claim 2, characterized in that: the main static ring assembly includes a main static ring (15), a first static ring seat (16), and a second static ring seat (17). One end of the second static ring seat (17) is slidably fitted outside the positioning shaft (13), one end of the first static ring seat (16) is sleeved on the outer side of the other end of the second static ring seat (17), a limiting ring (18) bent inward is provided at the other end of the first static ring seat (16), one end of the main static ring (15) abuts against the second static ring seat (17), and the limiting ring (18) presses on the other end of the main static ring (15).

5. The high-pressure-resistant integrated mechanical seal according to claim 4, characterized in that: a plurality of circumferentially evenly distributed connecting bolts (19) are provided on the outer side wall of the first static ring seat (16), and positioning holes (17.1) for inserting and mating the screw rods of the connecting bolts (19) are provided on the outer side wall of the second static ring seat (17); a plurality of positioning sliding grooves (3.1.1) extending along its axial direction are provided on the side wall of the first mounting groove (3.1), and the bolt heads of the connecting bolts (19) are respectively slidably fitted in the corresponding positioning sliding grooves (3.1.1).

6. The high-pressure-resistant integrated mechanical seal according to claim 4, characterized in that: A first sealing ring (20) is provided between the active ring (11) and the first mounting boss (5), a second sealing ring (21) is provided between the main static ring (15) and the second static ring seat (17), and a third sealing ring (22) is provided between the second static ring seat (17) and the positioning shaft (13). The first sealing ring (20), the second sealing ring (21), and the third sealing ring (22) are located on the same horizontal line.

7. The high-pressure-resistant assembled mechanical seal according to claim 1, characterized in that: The auxiliary seal includes an auxiliary moving ring assembly and an auxiliary static ring assembly. The auxiliary moving ring assembly includes an auxiliary moving ring (23) and an auxiliary moving ring seat (24). The auxiliary moving ring (23) is sleeved outside the second shaft sleeve (2), and one end of the auxiliary moving ring (23) abuts against the second mounting boss (7); one end of the auxiliary moving ring seat (24) is sleeved outside the first shaft sleeve (1), and the other end of the auxiliary moving ring seat (24) is sleeved outside the auxiliary moving ring (23).

8. The high-pressure-resistant assembled mechanical seal according to claim 7, characterized in that: The auxiliary static ring assembly includes an auxiliary static ring (25) and an auxiliary static ring seat (26). One end of the auxiliary static ring seat (26) is slidably fitted at the bottom inside the second mounting groove (4.1). An auxiliary static ring groove (26.2) is provided inside the other end of the auxiliary static ring seat (26). A support ring (27) is fitted inside the auxiliary static ring groove (26.2). One end of the auxiliary static ring (25) is fitted in the installation channel between the inner wall of the auxiliary static ring groove (26.2) and the outer wall of the support ring (27). The other end of the auxiliary static ring (25) abuts against the other end of the auxiliary moving ring (23) in a relatively rotatable manner; a second elastic compensation element is provided between the auxiliary static ring seat (26) and the bottom of the second mounting groove (4.1).

9. The high-pressure-resistant assembled mechanical seal according to claim 1, characterized in that: The first shaft sleeve (1), the second shaft sleeve (2), and the first mounting boss (5) are of an integral structure; an annular inner groove (1.1) is provided on the inner wall of the first shaft sleeve (1), and a plurality of first through holes (1.2) and second through holes (1.3) distributed circumferentially are respectively provided on the side walls at both ends of the first shaft sleeve (1). A plurality of the first through holes (1.2) communicate with one end of the inner groove near the first mounting boss (5), and a plurality of the second through holes (1.3) communicate with the other end of the inner groove (1.1).

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