Shaft sealing structure

Abstract

A shaft sealing structure comprises a sealing assembly connected between a main shaft and an end plate body. The sealing assembly comprises a shaft sleeve used for rotating along with the main shaft, a mounting flange used for allowing the shaft sleeve to axially penetrate, an air bag arranged between the mounting flange and the shaft sleeve and a flexible sealing element arranged between the air bag and the shaft sleeve. And the sealing assembly is fixed on the end plate main body through the mounting flange. On the one hand, the air bag is used as the front end of the mechanical seal, abrasion to the mechanical seal can be greatly reduced by combining the air bag and the flexible sealing element, when the mechanical seal fails, only the air inlet pressure of the air bag needs to be adjusted, the flexible sealing element slightly presses the spiral shaft sleeve, adjustment is easy, convenient and flexible, and the sealing effect is good. Normal production of equipment is ensured without shutdown; on the other hand, the overall structure is simple, and installation and maintenance are convenient.

Description

Technical Field

[0001] The utility model relates to the technical field of mechanical seals, in particular to a shaft seal structure. Background Art

[0002] The main shaft speed of the spiral ribbon mixer is relatively low. For general working conditions, packing seals are usually used. An oil guiding groove is arranged in the middle of the packing, and a top material part is arranged at the bottom end. The packing rope is pushed out by adjusting the bolt length to control the packing compression amount, so as to adjust the sealing effect. When the working conditions are relatively harsh, a baffle ring + mechanical seal form is adopted to reduce the impact of materials on the mechanical seal. At present, the above two schemes have high requirements for the coaxiality of the main shaft and the seal assembly. When the coaxiality is poor, the wear will accelerate, the service life will be significantly reduced, and the design life cannot be achieved. Moreover, the packing seal requires shutdown maintenance, and the bolts are tightened manually for adjustment. There is no standard for the adjustment distance and bolt torque, and accurate perception and adjustment by people are required. Content of the Utility Model

[0003] The purpose of the utility model is to overcome the above deficiencies of the prior art and provide a shaft seal structure that is convenient for installation and maintenance, can greatly reduce the wear of the main shaft seal, and improve the service life of easily worn parts.

[0004] The technical scheme of the utility model is: a shaft seal structure, including a seal assembly connected between the main shaft and the end plate main body; the seal assembly includes a shaft sleeve for rotating together with the main shaft, an installation flange for axially penetrating the shaft sleeve, an airbag arranged between the installation flange and the shaft sleeve, and a flexible seal element arranged between the airbag and the shaft sleeve; the seal assembly is fixed on the end plate main body through the installation flange.

[0005] Further, the airbag is arranged in the central groove of the installation flange. A trachea joint is connected to the airbag, and a trachea avoidance groove is arranged on the surface of the installation flange. The trachea joint extends out through the trachea avoidance groove and is connected to an inflation device through a trachea. A valve for adjusting the air intake pressure of the airbag is arranged on the trachea.

[0006] Further, the airbag is an annular airbag, and the annular airbag is of a split structure.

[0007] Further, the flexible seal element includes a packing rope; or the flexible seal element includes a packing rope and a flexible sleeve. The packing rope is arranged in the flexible sleeve, and the whole is arranged in the central groove of the installation flange and is wrapped by the airbag.

[0008] Further, a flexible gasket is arranged between the central groove of the installation flange and the airbag.

[0009] Furthermore, the shaft sleeve is a spiral shaft sleeve, and the spiral shaft sleeve is provided with a thread at the end extending into the mounting flange; the main shaft penetrates into the spiral shaft sleeve and is detachably sealed and connected to the spiral shaft sleeve.

[0010] Furthermore, the sealing assembly also includes a stopper ring connected to the end of the mounting flange facing the end plate body; the stopper ring is closed at the end facing the end plate body, and is provided with an inner ring groove at the end facing the mounting flange for accommodating the threaded area of the spiral sleeve, when the threaded area of the spiral sleeve extends into the stopper ring along the center groove of the mounting flange, a spiral sealing space is formed between the threaded area and the stopper ring.

[0011] Furthermore, the mounting flange is connected with a pressure plate at the end away from the end plate body, for axially pressing the airbag and the flexible sealing element.

[0012] Furthermore, the end plate body is an end plate weldment, an end plate flange seat is connected to the end plate weldment, and the sealing assembly is sealed and connected to the end plate flange seat via a mounting flange.

[0013] Furthermore, the annular end face of the mounting flange is provided with a plurality of symmetrically arranged first threaded holes for connecting to the end plate flange seat, and the annular surface is also provided with a plurality of symmetrically arranged second threaded holes for connecting to the pressure plate, and the first threaded holes and the second threaded holes are alternately arranged.

[0014] The beneficial effects of the utility model are as follows: on the one hand, when used as the front end of a mechanical seal, by combining an airbag with a flexible sealing element, the wear on the main shaft seal can be greatly reduced. When the mechanical seal fails, it is only necessary to adjust the air intake pressure of the airbag so that the flexible sealing element can lightly press the spiral sleeve. The adjustment is simple and flexible, ensuring normal production of the equipment without shutting down. On the other hand, the overall structure is simple, and installation and maintenance are convenient. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 This is a schematic diagram of the main shaft seal assembly of the mixer of the utility model embodiment;

[0016] Figure 2 This is a schematic diagram of the connection between the sealing assembly and the end plate flange seat of the embodiment of the utility model;

[0017] Figure 3 It is a schematic diagram of the disassembled structure of the sealing assembly of the embodiment of the utility model;

[0018] Figure 4 It is a connection cross-sectional view of the sealing assembly of an embodiment of the utility model.

[0019] Description of the accompanying drawings:

[0020] 1. Spindle;

[0021] 2. Sealing assembly; 21. Mounting flange; 22. Spiral shaft sleeve; 23. Air pipe joint; 24. Annular airbag; 25. Silicone sleeve; 26. Packing rope; 27. Pressure plate; 28. First screw; 29. Second screw; 210. Silicone gasket; 211. First sealing ring; 212. Second sealing ring; 213. Material retaining ring; 214. Air pipe avoidance groove; 215. First threaded hole; 216. Second threaded hole; 217. Third screw; 218. Fourth screw;

[0022] 3. End plate welding part; 31. End plate flange seat. Specific embodiments

[0023] The present invention will be further described in detail below in conjunction with the specification drawings and specific embodiments.

[0024] As Figures 1 to 4 shown: A shaft sealing structure includes a sealing assembly 2 connected between the main shaft 1 of the mixer and the end plate welding part 3. The sealing assembly 2 includes a spiral shaft sleeve 22 for rotating together with the main shaft 1, a mounting flange 21 for axially penetrating the spiral shaft sleeve 22, an annular airbag 24 provided between the mounting flange 21 and the spiral shaft sleeve 22, and a flexible sealing element provided between the annular airbag 24 and the spiral shaft sleeve 22. An end plate flange seat 31 is installed on the end plate welding part 3, and the sealing assembly 2 is fixed to the end plate flange seat 31 through the mounting flange 21.

[0025] In this embodiment, the main shaft 1 penetrates into the spiral shaft sleeve 22 and is fixedly connected to the spiral shaft sleeve 22. Specifically, a first sealing ring 211 is provided between the outer peripheral contact end surface of the spiral shaft sleeve 22 and the main shaft 1, and at least one circle of first mounting grooves for inlaying the first sealing ring 211 is provided on the inner wall of the spiral shaft sleeve 22. After the spiral shaft sleeve is hermetically installed with the first sealing ring 211, it is fixed to the main shaft 1 through the first screw 28, so that the spiral shaft sleeve 22 can rotate together with the main shaft 1. Among them, the first screw 28 passes through radially along the spiral shaft sleeve 22 and is fixed to the main shaft 1. By locking the spiral shaft sleeve 22 on the main shaft 1, it is convenient for processing and easy to replace in case of later wear.

[0026] In this embodiment, the end plate flange seat 31 is connected to the end plate welding part 3, and the connection method can be selected as welding or bolt connection. In this embodiment, it is preferably to weld the end plate flange seat 31 to the end plate welding part 3 for the threaded fixation of the mounting flange 21 and the end plate flange seat 31.

[0027] In this embodiment, the annular airbag is arranged in the central groove of the mounting flange 21, and a flexible gasket with a certain elasticity is also arranged in the central groove of the mounting flange 21 to provide additional sealing performance and protection, preventing the annular airbag from directly contacting the surface of the mounting flange, and ensuring that the annular airbag can expand uniformly and provide a good sealing effect during operation. The flexible gasket is preferably a silicone gasket 210, which has good elasticity and can provide reliable sealing and buffering effects. During installation, the silicone gasket 210 is first installed in the central groove of the mounting flange 21, and then the annular airbag 24 is pressed into the central groove of the mounting flange 21.

[0028] In this embodiment, the annular airbag 24 can adopt an integral structure or a split structure. Preferably, a split structure is adopted, that is, the annular airbag 24 is designed into at least two segments, and the adjacent segments are detachably connected, such as snap connection, bonding or threaded connection through a connecting piece, which is convenient for clamping and maintenance. A tracheal joint 23 is connected to the annular airbag 24, and a tracheal avoidance groove 214 is arranged on the surface of the mounting flange 21, so that the tracheal joint 23 of the annular airbag 14 can extend out through the tracheal avoidance groove 214 and be tracheally connected to the inflation device. It can be understood that in this embodiment, each segment of the split annular airbag 24 can also be designed into a structure with independent inflation. For example, when the annular airbag is designed into two segments, the two segments of the airbag extend out from the tracheal avoidance groove through their respective tracheal joints, and the airbags of each segment are inflated according to actual needs, so as to perform segmented adjustment of the pressure for the pressing forces in different directions of the spiral shaft sleeve to achieve the best sealing effect. Among them, a precision pressure reducing valve is also arranged on the trachea between the tracheal joint and the inflation device to facilitate the adjustment of the intake pressure of the annular airbag.

[0029] In this embodiment, a flexible sealing element is provided between the annular airbag 24 and the spiral shaft sleeve 22. The flexible sealing element includes a packing rope 26. By adjusting the intake pressure of the annular airbag 24, the pressing force of the packing rope 26 on the spiral shaft sleeve 22 is controlled, so as to achieve the best sealing effect. Since the packing rope 26 is in direct contact with the annular airbag 24, it will cause direct contact wear between the annular airbag 24 and the packing rope 26 and reduce the relative sliding between the annular airbag and the packing rope. Therefore, the flexible sealing element further includes a flexible sleeve with good elasticity provided between the packing rope 26 and the annular airbag 24. The flexible sleeve is preferably a silica gel sleeve 25. The silica gel sleeve 25 is of an annular structure to be adapted to the annular airbag 24 and the central groove of the mounting flange 21. During installation, after the packing rope 26 is coiled, it is loaded into the silica gel sleeve 25. Then, the packing rope 26 and the silica gel sleeve 25 as a whole are loaded into the central groove of the mounting flange 21 and are pressed in by being wrapped by the annular airbag 24. By providing the silica gel sleeve 25, the pressure of the annular airbag 24 can be made more uniform, avoiding direct contact wear between the annular airbag 24 and the packing rope 26 and reducing the relative sliding between the airbag and the packing rope; and the packing rope 26 is wrapped and pressed by the silica gel sleeve 25 and the annular airbag 24. When there is radial runout after the main shaft 1 and the end plate welding part 3 are assembled, the silica gel sleeve 25 and the annular airbag 24 can play a role in buffering and compensating for the shaft runout, reducing local severe wear on the packing rope 26.

[0030] In this embodiment, a pressing plate 27 is connected to the end of the mounting flange 21 far from the end plate flange seat 31 for axially pressing the annular airbag 24, the silica gel sleeve 25 and the packing rope 26. The pressing plate 27 is of an annular structure, and a through hole for passing through the spiral shaft sleeve 22 is provided in the middle, and connection holes for connecting with the mounting flange 21 are provided on the annular end surface around the through hole. Among them, a plurality of first threaded holes 215 symmetrically arranged and used for connecting with the end plate flange seat 21 are provided on the annular end surface of the mounting flange 21, and a plurality of second threaded holes 216 symmetrically arranged and used for connecting with the pressing plate 27 are also provided on this annular surface. The first threaded holes 215 and the second threaded holes 216 are staggered with each other. The number of both the first threaded holes 215 and the second threaded holes 216 is preferably four. The pressing plate 27 is fastened to the mounting flange 21 by a plurality of second screws 29, and the mounting flange 21 is fastened to the end plate flange seat 31 by a third screw 217.

[0031] In this embodiment, at least one circle of second mounting grooves is provided on the end surface of the mounting flange 21 at the end facing the end plate flange seat 31, and a second sealing ring 212 is embedded in the second mounting grooves, so that the mounting flange 21 is hermetically connected to the end plate flange seat 31 through the second sealing ring 212.

[0032] In this embodiment, the end of the spiral shaft sleeve 22 extending into the mounting flange 21 is provided with threads. The sealing assembly 2 further includes a material retaining ring 213, which is connected to the end of the mounting flange facing the end plate flange seat 31. The material retaining ring is closed at the end facing the end plate flange seat 31, and is provided with an inner ring groove at the end facing the mounting flange for accommodating the threaded area of the spiral shaft sleeve. When the threaded area of the spiral shaft sleeve 22 extends into the material retaining ring along the central groove of the mounting flange 21, a spiral sealing space is formed between the threaded area and the material retaining ring 213. When the viscosity of the material is relatively high, the threads on the spiral shaft sleeve 22 move with the main shaft 1 to urge the material to return to the cavity end. The outer ring surface of the material retaining ring 213 and the mounting flange 21 are fixed together by a plurality of fourth screws 218.

[0033] The overall installation method of this embodiment is as follows: The end plate flange seat 31 is welded to the end plate welding 3. The contact end face of the spiral shaft sleeve 22 and the main shaft 1 is fitted with a first sealing ring 211 and fixed to the main shaft 1 by a first screw 28 to rotate together with the main shaft 1. The material retaining ring 213 is fixed to the mounting flange 21 by a fourth screw 218. Then, the mounting flange 21 is fitted with a second sealing ring 212 and fixed to the end plate flange seat 31 by a third screw 217 to axially fix the material retaining ring 211. The silica gel gasket 210 is fitted into the central groove of the mounting flange 21, the annular airbag 24 is pressed into the central groove of the mounting flange 21. After the packing rope 26 is coiled, it is fitted into the silica gel sleeve 25. The packing rope 26 and the silica gel sleeve 25 as a whole are fitted into the central groove of the mounting flange 21 and wrapped and pressed by the annular airbag 24. Then, the pressing plate 27 is fixed to the mounting flange 21 by a second screw 29 to axially press the annular airbag 24, the silica gel sleeve 25 and the packing rope 26. The annular airbag 24 is connected to the air pipe through an air pipe joint 23.

[0034] During use, the intake pressure of the annular airbag 24 is adjusted through a precision pressure reducing valve on the air pipe, gradually adjusted from low pressure to high pressure. When the annular airbag 24 presses the silica gel sleeve 25 and the packing rope 26, and the packing rope 26 slightly presses the spiral shaft sleeve 22, the best sealing effect in use is achieved. Subsequently, as the packing rope 26 wears, the intake pressure of the annular airbag 24 can be gradually increased.

[0035] In summary, on the one hand, this embodiment is used at the front end of the mechanical seal. By combining the annular airbag with the flexible sealing element, the wear of the main shaft seal can be greatly reduced. When the mechanical seal fails, only the intake pressure of the annular airbag needs to be adjusted to make the packing rope slightly press the spiral shaft sleeve, which is simple and flexible to adjust, ensuring normal production of the equipment without shutdown. On the other hand, the overall structure is simple, facilitating installation and maintenance.

[0036] In addition, the term "connection" should be understood in a broad sense. For example, it may include fixed connection, detachable connection or integral connection; it may include direct connection, or indirect connection through an intermediate medium, and may also include the communication inside two elements. For those of ordinary skill in the art, the specific meaning of the above terms in this application can be understood according to specific circumstances.

[0037] In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include at least one of such features. In the description of this application, the meaning of "a plurality of" is at least two, such as two, three, etc., unless otherwise specifically defined.

[0038] Although the embodiments of this application have been shown and described above, it can be understood that the above embodiments are exemplary and should not be construed as limiting this application. Those of ordinary skill in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of this application.

Claims

1. A shaft sealing structure, comprising a sealing assembly connected between a main shaft and an end plate body; characterized in that, The sealing assembly includes a bushing for rotating together with the main shaft, a mounting flange for axially inserting the bushing, an airbag disposed between the mounting flange and the bushing, and a flexible sealing element disposed between the airbag and the bushing; the sealing assembly is fixed to the end plate body through the mounting flange.

2. The shaft seal structure according to claim 1, characterized in that, The airbag is disposed in the central groove of the mounting flange, a tracheal joint is connected to the airbag, and a tracheal avoidance groove is provided on the surface of the mounting flange. The tracheal joint extends out through the tracheal avoidance groove and is tracheally connected to an inflation device, and a valve for adjusting the intake pressure of the airbag is provided on the trachea.

3. The shaft seal structure according to claim 2, wherein, The airbag is an annular airbag, and the annular airbag is of a split structure.

4. The shaft seal structure according to claim 1, characterized in that, The flexible sealing element includes packing rope; or the flexible sealing element includes packing rope and a flexible sleeve. The packing rope is disposed in the flexible sleeve, and the whole is disposed in the central groove of the mounting flange and is wrapped by the airbag.

5. The shaft seal structure according to claim 1, characterized in that, A flexible gasket is provided between the central groove of the mounting flange and the airbag.

6. The shaft seal structure according to claim 1, characterized in that, The bushing is a spiral bushing, and the spiral bushing is provided with threads at the end extending into the mounting flange; the main shaft penetrates into the spiral bushing and is detachably and sealingly connected to the spiral bushing.

7. The shaft seal structure according to claim 6, characterized in that, The sealing assembly further includes a material blocking ring, which is connected to the end of the mounting flange facing the end plate body; the material blocking ring is closed at the end facing the end plate body, and an inner ring groove for accommodating the threaded area of the spiral bushing is provided at the end facing the mounting flange. When the threaded area of the spiral bushing extends into the material blocking ring along the central groove of the mounting flange, a spiral sealing space is formed between the threaded area and the material blocking ring.

8. The shaft seal structure according to claim 1, wherein A pressing plate is connected to the end of the mounting flange away from the end plate body for axially pressing the airbag and the flexible sealing element.

9. The shaft seal structure according to claim 8, characterized in that, The end plate body is an end plate welding, and an end plate flange seat is connected to the end plate welding. The sealing assembly is sealingly connected to the end plate flange seat through the mounting flange.

10. The shaft seal structure according to claim 9, wherein, A plurality of first threaded holes symmetrically arranged and used for connecting with the end plate flange seat are provided on the annular end face of the mounting flange, and a plurality of second threaded holes symmetrically arranged and used for connecting with the pressing plate are also provided on the annular end face. The first threaded holes and the second threaded holes are staggered with each other.

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