A mechanical seal structure

Abstract

The present invention relates to a mechanical seal structure in the field of mechanical seals, including an equipment barrel, a rotating shaft, a dynamic grinding ring, a static grinding ring, an outer body, an inner body and a center barrel, the rotating shaft is arranged inside the center barrel, the two realize synchronous operation, the center barrel is rotatably connected to the inner side of the inner body and the outer body, the outer body is connected to the equipment barrel by a flange bolt structure, the inner body is detachably connected to the inner side of the outer body, the outer body is provided with a nitrogen inlet and an annular distribution cavity connected to the nitrogen inlet, the inner body is evenly provided with a plurality of air ports corresponding to the annular distribution cavity, the static grinding ring is slidably connected to the inner body through an elastic connecting piece, a connecting groove is arranged on the outer wall of one end of the center barrel extending into the equipment barrel, the dynamic grinding ring is fixed in the connecting groove, and the static grinding ring conflicts with the dynamic grinding ring. The present application has a simple structure, and each component is convenient to install and disassemble, easy to maintain, and has a low design accuracy requirement for each gap part, low manufacturing difficulty, and convenient promotion and application.

Description

Technical Field

[0001] The invention belongs to the field of mechanical seals, and in particular relates to a mechanical seal structure. Background Art

[0002] The current chemical industry involves a variety of toxic and harmful dust or particles. The mechanical seals of some equipment such as mixing, augers, and screw conveyors in pressurized containers often face material leakage, resulting in equipment shutdown, environmental pollution, or casualties. The main reason is that most equipment in the chemical industry has certain defects in the mechanical seal structure, which cannot operate for a long time under special conditions of pressure and dust. Once the mechanical seal is slightly worn, the pressure will allow the gas to carry dust in, further aggravating the wear of the mechanical seal, a vicious cycle, and finally causing shaft locking, equipment damage, and material leakage. In the subsequent maintenance process, the entire mechanical seal structure needs to be replaced, increasing maintenance time and costs.

[0003] CN202022472592.0 discloses a gas-protected mechanical seal, including a balancing sleeve, an elastic compensation element, a main sealing static ring, a main sealing dynamic ring, a sleeve, an auxiliary sealing dynamic ring, an auxiliary sealing static ring, an elastic compensation element, an O-ring, a radial locking screw, an isolation gas inlet, an isolation liquid inlet, an isolation liquid outlet, etc. It forms a good sealing cavity by flushing in isolation gas and passing in isolation liquid, structurally reducing the influence of the medium itself or the impurities contained therein on the sealing surface, thereby ensuring the long-term stable operation of the mechanical seal. However, the structure of this technical solution is relatively complex, and it is necessary to pass in isolation liquid, and the gap between the balancing sleeve and the shaft seat adopts an air-sealed design, which has high requirements on the design accuracy of the gap part, is difficult to manufacture, and is inconvenient to install and maintain, which is not conducive to promotion and application.

[0004] Therefore, it is necessary to develop a new mechanical seal structure. Summary of the invention

[0005] The purpose of the present invention is to overcome the above-mentioned shortcomings and provide a mechanical sealing structure.

[0006] The technical solution proposed by the present invention is as follows:

[0007] A mechanical seal structure comprises an equipment cylinder, a rotating shaft, a dynamic grinding ring, a static grinding ring, an outer body, an inner body and a center cylinder, wherein the rotating shaft is arranged inside the center cylinder, and the center cylinder is tightly connected with the rotating shaft to realize synchronous operation, the center cylinder is rotatably connected to the inner side of the inner body and the outer body, the outer body is connected with the equipment cylinder through a flange bolt structure, the inner body is detachably connected to the inner side of the outer body, a nitrogen inlet is arranged on the outer body, and an annular distribution cavity connected with the nitrogen inlet is arranged inside the outer body, and a gas distribution cavity is arranged between the outer body and the inner body. At least one first rubber sealing ring is provided corresponding to the upper and lower parts of the annular distribution cavity, respectively. A plurality of air ports corresponding to the annular distribution cavity are evenly distributed on the inner body. A two-stage step hole with a larger upper end and a smaller lower end is provided on the inner side of the inner body. The static grinding ring is slidably connected in the two-stage step hole through an elastic connecting piece. A connecting groove is provided on the outer wall of one end of the center tube extending into the cylinder of the equipment. The dynamic grinding ring is fixed in the connecting groove, and the static grinding ring and the dynamic grinding ring are in conflict with each other to form a dynamic-static combination surface. The air port corresponds to one end of the static grinding ring close to the dynamic grinding ring.

[0008] Preferably, a second rubber seal is provided between one end of the central tube extending into the cylinder of the equipment and the rotating shaft, and the other end of the central tube is fixedly connected to the rotating shaft by a pin. By providing the second rubber seal, the material will not leak to the outside through the gap between the central tube and the rotating shaft, and the central tube is connected to the rotating shaft by a pin to prevent the central tube and the rotating shaft from rotating relative to each other, so as to achieve better protection for the rotating shaft.

[0009] Preferably, an embracing ring is provided at one end of the center tube extending below the outer body, and a pin hole matching the pin is provided on the embracing ring, the center tube and the rotating shaft are connected as one. By providing the embracing ring, the center tube can be prevented from being strung along the axial direction. The embracing ring, the center tube and the rotating shaft are connected as one by the pin. When disassembling the mechanical seal structure, the pin is loosened to pull the rotating shaft out of the center tube. The embracing ring can be removed by further loosening the pin, so that the center tube can be separated from the upper part of the outer body, thereby facilitating the replacement of the dynamic grinding ring and the static grinding ring.

[0010] Preferably, the connection groove and the dynamic grinding ring are tightly combined through a complementary concave-convex slot structure. A number of protrusions are evenly distributed in the connection groove of the center tube, and a number of grooves are distributed at corresponding positions at the corresponding ends of the dynamic grinding ring. The tight combination of the protrusions and the grooves can prevent the connection groove and the dynamic grinding ring from rotating relative to each other, and also facilitate the installation, removal and replacement of the dynamic grinding ring.

[0011] Preferably, the elastic connector includes a support ring, a positioning pin and a spring, one side of the support ring is tightly combined with the static grinding ring through a complementary concave-convex groove structure, and the other side of the support ring is evenly distributed with a plurality of positioning pins along the circumference, each positioning pin is inserted with a spring, and a positioning hole matching the positioning pin is provided on the step at the lower end of the two-stage step hole of the inner body, and the end of the positioning pin away from the support ring is slidably matched with the positioning hole, and the positioning pin is arranged parallel to the rotating shaft. The support ring and the static grinding ring are tightly combined through the complementary concave-convex groove structure, which is convenient for installation and disassembly. Through the cooperation of the positioning pin and the positioning hole, the support ring will not produce radial rotation. By setting the spring, the support ring has a certain amount of expansion and contraction in the axial direction to ensure that the static grinding ring can still conflict with the dynamic grinding ring after wear.

[0012] Preferably, a third rubber sealing ring is provided between the static grinding ring and the inner body, and the third rubber sealing ring is provided below the air port, which helps to prevent the nitrogen introduced along the air port from leaking to the outside from between the static grinding ring and the inner body, so that the introduced nitrogen can only be blown upward to the dynamic and static joint surfaces, thereby preventing dust from entering between the dynamic and static joint surfaces, and at the same time, the joint between the dynamic grinding ring and the static grinding ring can be cooled to extend the service life of the dynamic grinding ring and the static grinding ring.

[0013] Preferably, the dynamic grinding ring and the static grinding ring are both made of wear-resistant hard alloy material, such as ZG40SiMnCrMO or ZG35Cr2MoNiRe, etc., which have good wear resistance and long service life. Of course, other wear-resistant materials, such as ceramic materials, can also be selected.

[0014] Preferably, a graphite sealing ring is installed between the outer wall of the central tube and the inner body, and the graphite sealing ring abuts against the bottom of the outer body. Since graphite has good sealing and smoothness, the graphite sealing ring can provide good sealing even when the outer wall of the central tube and the inner body are in a relative rotation state.

[0015] Preferably, the bottom of the inner body is evenly distributed with a plurality of threaded rods, the bottom of the outer body is provided with through holes corresponding to the threaded rods, the bottom of the threaded rods passes through the through holes and is threadedly connected with nuts, and the nuts abut against the bottom of the outer body. The inner body and the outer body are connected by the threaded rods and nuts, which is convenient for assembly and disassembly.

[0016] The present invention also includes other devices or components that enable the normal use of the mechanical seal structure, and these devices or components all adopt conventional technical means in the art. In addition, the devices and components not limited in the present invention all adopt conventional technical means in the art, such as the first rubber seal ring, the second rubber seal ring and the third rubber seal ring in the present application all adopt O-type rubber seal rings commonly used in the art, and the inner body, the outer body and the center tube are respectively provided with seal ring installation grooves that match the first rubber seal ring, the second rubber seal ring and the third rubber seal ring. In addition, the flange bolt structure and the concave-convex slot structure in the present application are both commonly used technical means in the art, and will not be repeated here.

[0017] The working principle of the present application is that, when in use, the nitrogen inlet is connected to an external nitrogen gas source, and the nitrogen is turned on before each equipment start-up, so that the nitrogen can be evenly distributed around the dynamic grinding ring and the static grinding ring through the nitrogen inlet, the annular distribution cavity, and the gas port, thereby preventing the material in the pressurized equipment from flowing back into the dynamic and static joint surfaces of the dynamic grinding ring and the static grinding ring to cause wear. At the same time, the nitrogen can also take away the heat generated by the friction of the dynamic and static joint surfaces, thereby increasing the service life of the mechanical sealing mechanism.

[0018] The synchronous operation is realized by setting the central cylinder and the rotating shaft to be closely connected, so as to avoid leakage of materials from the gap between the rotating shaft and the central cylinder, and at the same time, the rotating shaft is safely protected. The outer body and the inner body are relatively statically arranged, and the first rubber sealing ring is used to seal the upper and lower parts of the annular distribution cavity to prevent leakage of materials along the joint surface of the outer body and the inner body to the outside, and at the same time, the nitrogen input into the annular distribution cavity will not leak along the joint surface of the outer body and the inner body, so that the nitrogen enters the corresponding positions of the dynamic grinding ring and the static grinding ring through the gas port, which, on the one hand, avoids the material from entering the dynamic and static joint surface, and on the other hand, the joint part of the dynamic grinding ring and the static grinding ring is The cooling is performed to extend the service life of the dynamic grinding ring and the static grinding ring. The contact surfaces of the dynamic grinding ring and the static grinding ring of the present application are relatively flat. Due to the presence of the spring, the pressure of the contact surface of the dynamic grinding ring and the static grinding ring is adjustable to a certain extent. It is not a hard contact, which can reduce wear. When the contact surfaces of the dynamic grinding ring and the static grinding ring are worn due to long-term operation, the spring can push the static grinding ring upward to compensate for the gap caused by wear, reduce leakage, and increase service life. Even if the sealing effect of the dynamic and static joint surfaces of the dynamic grinding ring and the static grinding ring changes, only nitrogen will leak, not the material, thereby ensuring the sealing performance of the material in the equipment.

[0019] It should be noted that the mechanical seal structure in the present application is only used as a sealing part of the equipment and cannot withstand excessive axial and radial forces brought by the rotating shaft.

[0020] Compared with the prior art, the beneficial effects achieved by the present invention are:

[0021] The present application has a simple structure, does not need to be filled with an isolation fluid, and the components are easy to install and disassemble and maintain. In addition, the design accuracy requirements for each gap portion are relatively low, the manufacturing difficulty is small, and it is easy to promote and apply. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a schematic diagram of the overall structure of the present invention in the embodiment.

[0023] Figure 2 for Figure 1 A-section structure enlarged schematic diagram.

[0024] Figure 3 for Figure 1 Schematic diagram of the enlarged structure of part B. DETAILED DESCRIPTION

[0025] The technology of the present invention is further described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[0026] Example:

[0027] like Figures 1 to 3 As shown, the present invention provides a mechanical seal structure, including an equipment barrel 1, a rotating shaft 2, a dynamic grinding ring 3, a static grinding ring 4, an outer body 5, an inner body 6 and a center barrel 7, wherein the rotating shaft 2 is passed through the center barrel 7, and the center barrel 7 is tightly connected to the rotating shaft 2 to realize synchronous operation, the center barrel 7 is rotatably connected to the inner side of the inner body 6 and the outer body 5, the outer body 5 is connected to the equipment barrel 1 through a flange bolt structure 8, the inner body 6 is detachably connected to the inner side of the outer body 5, a nitrogen inlet 9 is provided on the outer body 5, and an annular distribution chamber 10 connected to the nitrogen inlet 9 is provided on the inner side of the outer body 5, the outer body 5 is connected to the inner body 6, and the inner side of the outer body 5 is connected to the inner body 6. A first rubber sealing ring 11 is respectively provided between the inner body 6 and corresponding to the upper and lower parts of the annular distribution cavity 10. Six air ports 12 corresponding to the annular distribution cavity 10 are evenly distributed on the inner body 6. A two-stage step hole 13 with a larger upper end and a smaller lower end is provided on the inner side of the inner body 6. The static grinding ring 4 is slidably connected in the two-stage step hole 13 through an elastic connecting piece. A connecting groove 14 is provided on the outer wall of one end of the center tube 7 extending into the equipment cylinder 1. The dynamic grinding ring 3 is fixed in the connecting groove 14, and the static grinding ring 4 conflicts with the dynamic grinding ring 3 to form a dynamic-static combination surface. The air port 12 corresponds to one end of the static grinding ring 4 close to the dynamic grinding ring 3.

[0028] As a further improvement to the above scheme, a second rubber seal ring 15 is provided between one end of the central tube 7 extending into the equipment cylinder 1 and the rotating shaft 2, and the other end of the central tube 7 is fixedly connected to the rotating shaft 2 via a pin 16. By providing the second rubber seal ring 15, the material will not leak to the outside along the gap between the central tube 7 and the rotating shaft 2, and the central tube 7 is connected to the rotating shaft 2 via the pin 16 to prevent the central tube 7 and the rotating shaft 2 from rotating relative to each other, so as to achieve better protection for the rotating shaft 2.

[0029] As a further improvement to the above scheme, a ring 17 is provided at one end of the center tube 7 extending below the outer body 5, and a pin hole matching the pin 16 is provided on the ring 17, and the pin 16 connects the ring 17, the center tube 7 and the rotating shaft 2 as a whole. By providing the ring 17, the center tube 7 can be prevented from being strung along the axial direction, and the ring 17, the center tube 7 and the rotating shaft 2 are connected as a whole by the pin 16. When disassembling the mechanical seal structure, the pin 16 is loosened, and the rotating shaft 2 can be pulled out of the center tube 7. The ring 17 can be removed by further loosening the pin 16, so that the center tube 7 can be separated from the top of the outer body 5, thereby facilitating the replacement of the dynamic grinding ring 3 and the static grinding ring 4.

[0030] As a further improvement to the above scheme, the connection groove 14 is tightly combined with the dynamic grinding ring 3 through a complementary concave-convex groove structure 18. In this embodiment, a number of protrusions are evenly distributed in the connection groove 14 of the center tube 7, and a number of grooves are distributed at corresponding positions at the corresponding ends of the dynamic grinding ring 3. Through the tight combination of the protrusions and the grooves, the connection groove 14 and the dynamic grinding ring 3 can be prevented from relative rotation, and the installation, removal and replacement of the dynamic grinding ring 3 are also convenient.

[0031] As a further improvement to the above scheme, the elastic connector includes a support ring 19, a positioning pin 20 and a spring 21. One side of the support ring 19 is also tightly combined with the static grinding ring 4 through a complementary concave-convex groove structure 18, and the other side of the support ring 19 is evenly distributed with a plurality of positioning pins 20 along the circumferential direction, and each positioning pin 20 is interspersed with a spring 21. The step at the lower end of the two-stage step hole 13 of the inner body 6 is provided with a positioning hole matching the positioning pin 20, and the end of the positioning pin 20 away from the support ring 19 is slidably matched with the positioning hole, and the positioning pin 20 is arranged parallel to the rotating shaft 2. The support ring 19 is tightly combined with the static grinding ring 4 through the complementary concave-convex groove structure 18, which is convenient for installation and disassembly. Through the cooperation of the positioning pin 20 and the positioning hole, the support ring 19 will not produce radial rotation. By setting the spring 21, the support ring 19 has a certain amount of expansion and contraction in the axial direction to ensure that the static grinding ring 4 can still conflict with the dynamic grinding ring 3 after wear.

[0032] As a further improvement to the above scheme, a third rubber sealing ring 22 is provided between the static grinding ring 4 and the inner body 6, and the third rubber sealing ring 22 is provided below the air port 12, which helps to prevent the nitrogen introduced along the air port 12 from leaking to the outside from between the static grinding ring 4 and the inner body 6, so that the introduced nitrogen can only be blown upward to the dynamic and static joint surfaces, thereby preventing dust from entering between the dynamic and static joint surfaces, and at the same time, the joint between the dynamic grinding ring 3 and the static grinding ring 4 can be cooled to extend the service life of the dynamic grinding ring 3 and the static grinding ring 4.

[0033] As a further improvement to the above scheme, the dynamic grinding ring 3 and the static grinding ring 4 are both made of wear-resistant hard alloy material ZG40SiMnCrMO, which has good wear resistance and long service life. Of course, in other embodiments of the present application, other wear-resistant materials such as ceramics can also be selected.

[0034] As a further improvement to the above solution, a graphite sealing ring 23 is installed between the outer wall of the central tube 7 and the inner body 6, and the graphite sealing ring 23 abuts against the bottom of the outer body 5. Since graphite has good sealing and smoothness, the graphite sealing ring 23 can also provide good sealing even if the outer wall of the central tube 7 and the inner body 6 are in a relatively rotating state.

[0035] As a further improvement to the above solution, the bottom of the inner body 6 is evenly distributed with 6 threaded rods 24, the bottom of the outer body 5 is provided with through holes 25 corresponding to the threaded rods 24, the bottom of the threaded rods 24 passes through the through holes 25 and is threadedly connected with nuts 26, and the nuts 26 abut against the bottom of the outer body 5. The inner body 6 and the outer body 5 are connected by the threaded rods 24 and the nuts 26, which is convenient for assembly and disassembly.

[0036] It should be noted that the first rubber seal ring 11, the second rubber seal ring 15 and the third rubber seal ring 22 in this embodiment are all O-type rubber seal rings commonly used in the art, and the inner body 6, the outer body 5 and the center tube 7 are respectively provided with seal ring installation grooves matching the first rubber seal ring 11, the second rubber seal ring 15 and the third rubber seal ring 22. And the mechanical seal structure is only used as a sealing part of the equipment, and cannot withstand excessive axial and radial forces brought by the rotating shaft 2.

[0037] When in use, the nitrogen inlet 9 is connected to an external nitrogen source. Before each equipment start-up, the nitrogen is turned on, and the nitrogen can be evenly distributed around the dynamic grinding ring 3 and the static grinding ring 4 through the nitrogen inlet 9, the annular distribution cavity 10, and the gas port 12, so that the material in the pressurized equipment can be prevented from entering the dynamic and static joint surfaces of the dynamic grinding ring 3 and the static grinding ring 4 and causing wear. At the same time, the nitrogen can also take away the heat generated by the friction of the dynamic and static joint surfaces, thereby increasing the service life of the mechanical sealing mechanism.

[0038] Synchronous operation is achieved by setting the central tube 7 to be closely connected with the rotating shaft 2. Due to the provision of the pin 16 and the second rubber sealing ring 15, the possibility of material leakage from the gap between the rotating shaft 2 and the central tube 7 is further reduced, and at the same time, good safety protection is achieved for the rotating shaft 2. The outer body 5 and the inner body 6 are relatively stationary, and the first rubber sealing ring 11 is used to seal the upper and lower parts of the annular distribution chamber 10 to prevent the material from leaking to the outside along the joint surface of the outer body 5 and the inner body 6. At the same time, the nitrogen input into the annular distribution chamber 10 will not leak along the joint surface of the outer body 5 and the inner body 6, so that the nitrogen enters the corresponding positions of the dynamic grinding ring 3 and the static grinding ring 4 through the gas port 12, on the one hand, preventing the material from entering the dynamic and static joint surface, and on the other hand, cooling the joint of the dynamic grinding ring 3 and the static grinding ring 4, thereby extending the service life of the dynamic grinding ring 3 and the static grinding ring 4. Due to the provision of the third rubber sealing ring 22, the leakage path of the material can only be through the joint of the dynamic grinding ring 3 and the static grinding ring 4 The surface leaks outward along the outer wall of the center tube 7. To avoid this leakage, the present application adopts the following three protections: the first protection is that the contact surfaces of the dynamic grinding ring 3 and the static grinding ring 4 are relatively flat. Because of the presence of the spring 21, the pressure of the contact surface of the dynamic grinding ring 3 and the static grinding ring 4 is adjustable to a certain extent, and it is not a hard contact, which can reduce wear. When the contact surface of the dynamic grinding ring 3 and the static grinding ring 4 is worn due to long-term operation, the spring 21 can push the static grinding ring 4 upward to compensate for the spacing caused by wear, reduce leakage, and increase service life; the second protection is that a graphite sealing ring 23 is installed between the outer wall of the center tube 7 and the inner body 6. Graphite has good sealing and smoothness. Even if the outer wall of the center tube 7 and the inner body 6 are in a relative rotation state, the graphite sealing ring 23 can also play a good sealing role; the third protection is that the gas ports 12 evenly distributed on the inner side of the inner body 6, the gas ejected can protect the dynamic and static joint surfaces and prevent materials from entering the gap between the dynamic and static joint surfaces. Even if the sealing effects of the first and second lines of protection change, only nitrogen will leak, not the material, thus ensuring the sealing performance of the material in the equipment.

[0039] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A mechanical seal structure, comprising a device barrel, a rotating shaft, a dynamic grinding ring, and a static grinding ring, characterized in that: It also includes an outer body, an inner body and a center tube, the rotating shaft is passed through the inside of the center tube, and the center tube is tightly connected with the rotating shaft to realize synchronous operation, the center tube is rotatably connected to the inner side of the inner body and the outer body, the outer body is connected with the equipment cylinder by a flange bolt structure, the inner body is detachably connected to the inner side of the outer body, a nitrogen inlet is provided on the outer body, and an annular distribution cavity connected with the nitrogen inlet is provided on the inner side of the outer body, at least one first rubber sealing ring is provided between the outer body and the inner body and corresponding to the upper and lower sides of the annular distribution cavity, a plurality of gas ports corresponding to the annular distribution cavity are evenly distributed on the inner body, a two-stage step hole with a larger upper end and a smaller lower end is provided on the inner side of the inner body, the static grinding ring is slidably connected in the two-stage step hole through an elastic connecting piece, a connecting groove is provided on the outer wall of one end of the center tube extending into the equipment cylinder, the dynamic grinding ring is fixed in the connecting groove, and the static grinding ring and the dynamic grinding ring are in conflict with each other to form a dynamic-static combination surface, and the gas port corresponds to one end of the static grinding ring close to the dynamic grinding ring; The connecting groove and the dynamic grinding ring are tightly combined through a complementary concave-convex groove structure; The elastic connecting member includes a supporting ring, a positioning pin and a spring. One side of the supporting ring is tightly combined with the static grinding ring through a complementary concave-convex groove structure, and the other side of the supporting ring is evenly distributed with a plurality of positioning pins along the circumference, and each positioning pin is inserted with a spring. A positioning hole matching the positioning pin is provided on the step at the lower end of the two-stage step hole of the inner body, and the end of the positioning pin away from the supporting ring is slidably matched with the positioning hole, and the positioning pin is arranged parallel to the rotating shaft; A third rubber sealing ring is provided between the static grinding ring and the inner body, and the third rubber sealing ring is provided below the air port; A graphite sealing ring is installed between the outer wall of the central tube and the inner body, and the graphite sealing ring abuts against the bottom of the outer body; The upper part of the inner body has a radially outward protrusion, which cooperates with the upper surface of the outer body to limit the downward movement of the inner body. The end of the center tube extending below the outer body is provided with an embracing ring, and the embracing ring is provided with a pin hole matching the pin. The pin connects the embracing ring, the center tube and the rotating shaft as a whole. The bottom of the inner body is evenly distributed with a plurality of threaded rods, and the bottom of the outer body is provided with through holes corresponding to the threaded rods. The bottom of the threaded rod passes through the through holes and is threadedly connected with a nut, and the nut abuts against the bottom of the outer body.

2. The mechanical seal structure according to claim 1, characterized in that: A second rubber sealing ring is arranged between one end of the central tube extending into the equipment cylinder and the rotating shaft, and the other end of the central tube is fixedly connected to the rotating shaft through a pin.

3. The mechanical seal structure according to claim 1, characterized in that: The dynamic grinding ring and the static grinding ring are both made of wear-resistant hard alloy.

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