Self-compensating sealing device

Abstract

The utility model discloses a self-compensating type sealing device which comprises a sealing assembly and a corrugated pipe assembly, the sealing assembly comprises a driving sleeve assembly and a fixing structure arranged on the outer side of the driving sleeve assembly, the driving sleeve assembly tightly holds a rotating shaft and synchronously rotates along with the rotating shaft, one end of the corrugated pipe assembly is connected with the fixing structure of the sealing assembly, and the other end of the corrugated pipe assembly is connected with the sealing assembly. The other end of the corrugated pipe assembly is fixedly connected with the mounting surface; the lower end of the fixing structure of the sealing assembly is connected with the corrugated pipe assembly, the corrugated pipe assembly bears the axial load and allows the whole sealing assembly installed on the corrugated pipe assembly to deflect in a small range in the radial direction, the swing amount generated by a rotating shaft is counteracted, and therefore the sealing assembly at the upper end is protected.

Description

Technical Field

[0001] The utility model relates to the technical field of sealing, in particular to a self-compensating sealing device. Background Art

[0002] The application of magnetic liquid sealing technology in sealing technology is one of its most important achievements. After decades of development, magnetic liquid sealing has been widely used in many fields such as national defense, aerospace, machinery, electronics, instrumentation, atomic energy, chemical industry, and pharmaceuticals. In particular, it has performed very well in three aspects: dustproof sealing, vacuum sealing, and pressure differential sealing. For example, the sealing of important mechanical rotating parts, especially in the rotating shaft as the dynamic leakage-proof part of the equipment, has outstanding advantages, which can achieve the purpose of leakage prevention without affecting the movement of movable parts. Therefore, the application scope of magnetic liquid sealing technology is becoming wider and wider.

[0003] At present, the magnetic liquid sealing technology used as the dynamic seal of the rotating shaft generally adopts a typical two-pole magnetic liquid dynamic sealing device, which is composed of a permanent magnet (circular ring), two magnetic poles (ring-shaped discs), a rotating shaft and a magnetic liquid. Since the NS poles of the permanent magnet in the device are distributed axially and the two magnetic poles and the rotating shaft are made of magnetic conductive materials, under the action of the magnetic field, a closed magnetic circuit is formed, which is formed along the surface of the rotating shaft in the NS interval; there is a gap between the two magnetic poles and the rotating shaft, and the two gaps are distributed in a ring shape around the outer circle of the cross section of the rotating shaft. These two annular gaps are what we usually call the "air gap" in the magnetic field magnetic circuit, and the magnetic field intensity in the air gap of the magnetic field magnetic circuit is the largest; the magnetic liquid seal makes use of this magnetic phenomenon, and injects a magnetic liquid with superparamagnetic characteristics into it. Under the action of the magnetic field, the magnetic liquid is stably adsorbed and fills the two gaps between the rotating shaft and the magnetic poles, realizing the separation of the space at both ends of the magnetic field and forming a reliable seal.

[0004] However, at the current stage in the chemical industry, due to excessive swing of some agitator shafts during operation, the sealing device is subjected to a huge swing, which greatly reduces the service life of the sealing device, causing it to fail or be damaged faster, resulting in medium leakage, causing serious harm to the environment, personal safety and production facilities. Utility Model Content

[0005] The purpose of the utility model is to provide a self-compensating sealing device, which can withstand high pressure, resist stress and damping, offset the swing amount generated by the rotating shaft, and protect the upper end sealing component while being corrosion-resistant through the flexibility and extensibility of the bellows component.

[0006] The utility model is realized by the following technical solutions:

[0007] A self-compensating sealing device, comprising:

[0008] A sealing assembly, the sealing assembly comprising a driving sleeve assembly and a fixing structure arranged outside the driving sleeve assembly, the driving sleeve assembly is tightly held on the rotating shaft and rotates synchronously with the rotating shaft;

[0009] A bellows assembly, one end of which is connected to the fixed structure of the sealing assembly, and the other end of which is fixedly connected to the mounting surface.

[0010] In this solution, the sealing assembly includes a driving sleeve assembly for forming a sealing structure and a fixed structure arranged on the outside of the driving sleeve assembly. The driving sleeve assembly is tightly embraced by the rotating shaft and rotates synchronously with the rotating shaft. The fixed structure is connected to the bellows assembly. The bellows assembly is flexible and extensible. While bearing the axial load, it allows the sealing assembly installed thereon to have a small range of radial deflection as a whole, offsetting the swing amount generated by the rotating shaft, thereby protecting the sealing assembly at the upper end.

[0011] As a further technical solution of the magnetic liquid sealing device, the sealing assembly further comprises a rotating disk, the rotating disk is connected to the driving sleeve assembly, and the rotating disk extends radially along the rotating shaft, and the upper and lower ends of the rotating disk are respectively provided with a first magnetic liquid seal and a second magnetic liquid seal;

[0012] Wherein, an end face magnetic liquid sealing structure along the radial array of the rotating shaft is formed between the first magnetic liquid sealing member and the second magnetic liquid sealing member and the rotating disk.

[0013] In the present scheme, the turntable rotates synchronously with the rotating shaft through the driving sleeve assembly, and the outer end of the turntable extends radially along the rotating shaft. At the same time, the first magnetic liquid seal and the second magnetic liquid seal are respectively arranged radially along the rotating shaft at the upper and lower ends of the turntable. In the working state, the driving sleeve assembly drives the turntable to rotate, and the first magnetic liquid seal, the second magnetic liquid seal and the turntable form a closed magnetic circuit, and a non-uniform magnetic field with alternating strong and weak strengths is generated in the tooth-shaped gap, which tightly absorbs the magnetic liquid, so that an end face magnetic liquid sealing structure is formed between the first magnetic liquid seal, the second magnetic liquid seal and the turntable. The structure is compact, saves axial space and reasonably uses radial space, avoiding the situation where the sealing device cannot be arranged due to the limitation of axial size.

[0014] As a further technical solution of the magnetic liquid sealing device, the drive sleeve assembly includes a clamping sleeve and a drive sleeve, the lower end of the clamping sleeve is connected to the drive sleeve, the drive sleeve is connected to the turntable through a third cylindrical head screw, the outer end of the clamping sleeve is clamped to the rotating shaft through a locking sleeve, and the torque is transmitted to the turntable through the expansion force between the clamping sleeve and the rotating shaft.

[0015] As a further technical solution of the magnetic liquid sealing device, the axial cross section of the expansion sleeve is a trapezoidal shape protruding in the radial direction, and the locking sleeve includes a first locking sleeve and a second locking sleeve;

[0016] The first locking sleeve and the second locking sleeve are respectively in contact with the two trapezoidal inclined surfaces of the expansion sleeve, and a fourth cylindrical head screw is threadedly connected between the first locking sleeve and the second locking sleeve. The second locking sleeve moves longitudinally under the threaded engagement of the fourth cylindrical head screw, and the longitudinal displacement of the second locking sleeve is adjusted by the fourth cylindrical head screw, thereby adjusting the expansion force between the expansion sleeve and the rotating shaft.

[0017] As a further technical solution to the magnetic liquid sealing device, a plurality of groups of fourth O-rings are arranged between the drive sleeve and the outer wall of the rotating shaft. The plurality of groups of fourth O-rings are arranged in an axial array to prevent the medium from leaking along the gap between the drive sleeve and the rotating shaft. A third O-ring is arranged between the drive sleeve and the turntable to prevent the medium from leaking along the gap between the drive sleeve and the turntable.

[0018] As a further technical solution of the magnetic liquid sealing device, the fixed structure includes an upper plate and a bottom plate, and the upper plate and the bottom plate are respectively connected to the upper and lower ends of the spacer and form a rotating cavity for accommodating the turntable, which is used to isolate the end face magnetic liquid sealing structure from the external environment. The contact surfaces of the upper plate and the bottom plate with the spacer are respectively provided with a second O-ring to prevent the medium from leaking along the gap between the upper plate and the bottom plate and the spacer.

[0019] As a further technical solution of the magnetic liquid sealing device, the first magnetic liquid seal and the second magnetic liquid seal also include permanent magnets and pole shoes. The pole shoes and the permanent magnets are arranged alternately in a radial direction of the turntable to enhance the sealing performance of the end face magnetic liquid sealing structure.

[0020] As a further technical solution of the magnetic liquid sealing device, a pole shoe spacer is provided between the permanent magnet and the turntable to prevent the permanent magnet from being driven to rotate and generating friction.

[0021] As a further technical solution of the magnetic liquid sealing device, a bearing is arranged between the turntable and the spacer, the inner ring of the bearing is connected to the outer end of the turntable, and the outer ring of the bearing is connected to the inner end of the spacer. By fixing the turntable and the bearing, the inner ring of the bearing can rotate with the turntable, and the bearing can ensure that the sealing device can withstand certain radial loads and axial loads.

[0022] As a further technical solution of the magnetic liquid sealing device, bearing baffles are respectively provided at both ends of the contact surface between the inner ring of the bearing and the turntable, and the bearing baffles are tightened by a second cylindrical head screw thread to prevent the bearing from falling off when the sealing device is subjected to radial load and axial load.

[0023] Compared with the prior art, the utility model has the following advantages and beneficial effects:

[0024] 1. The utility model connects a bellows assembly to the lower end of the fixed structure of the sealing assembly. The bellows assembly allows the sealing assembly installed thereon to have a small radial deflection as a whole while bearing the axial load, thereby offsetting the swing amount generated by the rotating shaft, thereby protecting the sealing assembly at the upper end.

[0025] 2. The turntable of the utility model rotates synchronously with the rotating shaft through the driving sleeve assembly, and the outer end of the turntable extends radially along the rotating shaft. At the same time, the first magnetic liquid seal and the second magnetic liquid seal are respectively arranged radially along the rotating shaft at the upper and lower ends of the turntable. In the working state, the driving sleeve assembly drives the turntable to rotate, and the first magnetic liquid seal, the second magnetic liquid seal and the turntable form a closed magnetic circuit, and a non-uniform magnetic field with alternating strong and weak strengths is generated in the tooth-shaped gap, which tightly absorbs the magnetic liquid, so that an end face magnetic liquid sealing structure is formed between the first magnetic liquid seal, the second magnetic liquid seal and the turntable. The structure is compact, saves axial space and reasonably uses radial space, avoiding the situation where the sealing device cannot be arranged due to the limitation of axial size. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The drawings described herein are used to provide a further understanding of the embodiments of the present utility model, constitute a part of this application, and do not constitute a limitation of the embodiments of the present utility model. In the drawings:

[0027] Figure 1 It is a three-dimensional structural schematic diagram of the utility model;

[0028] Figure 2 It is a schematic diagram of the top view structure of the utility model;

[0029] Figure 3 for Figure 2 A schematic diagram of a cross-sectional structure marked AA in the figure;

[0030] Figure 4 for Figure 3 Schematic diagram of the enlarged structure marked as B.

[0031] Marks and corresponding parts names in the attached drawings:

[0032] 1-seal assembly; 2-bellows assembly; 3-bellows; 4-first O-ring; 5-permanent magnet; 6-pole shoe spacer; 7-base plate; 8-second O-ring; 9-spacer; 10-bearing; 11-first cylindrical head screw; 12-upper plate; 13-turntable; 14-bearing baffle; 15-second cylindrical head screw; 16-third O-ring; 17-third cylindrical head screw; 18-first locking sleeve; 19-fourth cylindrical head screw; 20-expansion sleeve; 21-second locking sleeve; 22-drive sleeve; 23-fourth O-ring; 24-pole tooth; 25-pole shoe; 26-first mounting plate; 27-second mounting plate. DETAILED DESCRIPTION

[0033] In order to make the purpose, technical solutions and advantages of the utility model more clearly understood, the utility model is further described in detail below in conjunction with embodiments and drawings. The schematic implementation manner of the utility model and its description are only used to explain the utility model and are not intended to limit the utility model.

[0034] Example

[0035] This embodiment provides a self-compensating sealing device, such as Figure 1-Figure 4 As shown, it includes a sealing component 1 and a bellows component 2. The sealing component 1 can use sealing devices such as mechanical seals or magnetic liquid seals. This embodiment mainly discusses the magnetic liquid sealing device, so the sealing component 1 includes a turntable 13, a drive sleeve component and a fixed structure arranged on the outside of the drive sleeve component.

[0036] Among them, Figure 1-Figure 4 As shown, the fixed structure includes a first mounting plate 26, and the bellows assembly 2 includes a bellows 3, which is a metal bellows. The upper end of the bellows 3 is connected to the first mounting plate 26 through a fastener, and the lower end of the bellows 3 is connected to the second mounting plate 27 through a fastener. When the sealing assembly as a whole has a small range of radial deflection, the bellows 3 can offset the swing amount generated by the rotating shaft.

[0037] For the specific structure of the sealing component 1 in this embodiment, please refer to Figure 1-Figure 4 As shown, the drive sleeve assembly is tightly clamped to the rotating shaft (not shown in the figure) and rotates synchronously with the rotating shaft. The drive sleeve assembly includes a clamping sleeve 20 and a drive sleeve 22. The lower end of the clamping sleeve 20 is connected to the drive sleeve 22, and the drive sleeve 22 is connected to the turntable 13 through the third cylindrical head screw 17. The outer end of the clamping sleeve 20 is clamped to the rotating shaft through the locking sleeve, and the torque is transmitted to the turntable 13 through the expansion force between the clamping sleeve 20 and the rotating shaft.

[0038] Specifically, the above-mentioned expansion sleeve 20 is an annular sleeve, and the axial cross-section of the expansion sleeve 20 is a trapezoidal shape protruding in the radial direction. The circumferential side wall of the expansion sleeve 20 is evenly distributed with penetrating compensation seams, and the locking sleeve includes a first locking sleeve 18 and a second locking sleeve 21, which are respectively abutted against the two trapezoidal inclined surfaces of the expansion sleeve 20. A fourth cylindrical head screw 19 is also threadedly connected between the first locking sleeve 18 and the second locking sleeve 21. The second locking sleeve 21 moves longitudinally under the threaded engagement of the fourth cylindrical head screw 19. When the expansion sleeve 20 needs to be clamped to the rotating shaft, it is only necessary to adjust the longitudinal displacement of the second locking sleeve 21 through the fourth cylindrical head screw 19 to adjust the expansion force between the expansion sleeve 20 and the rotating shaft.

[0039] At the same time, in order to prevent the medium from leaking along the gap between the drive sleeve 22 and the turntable 13, multiple groups of fourth O-rings 23 are arranged between the drive sleeve 22 and the outer wall of the rotating shaft. In this embodiment, two groups are arranged. The two groups of fourth O-rings 23 are arranged in an axial array, which can prevent the medium from leaking along the gap between the drive sleeve 22 and the rotating shaft. In order to further prevent the medium from leaking along the gap between the drive sleeve 22 and the turntable 13, a third O-ring 16 is arranged between the drive sleeve 22 and the turntable 13.

[0040] Please refer to Figure 1-Figure 4 As shown, the above-mentioned fixing structure further includes an upper plate 12 and a bottom plate 7 , and the first magnetic liquid seal and the second magnetic liquid seal both include a permanent magnet 5 and a pole shoe 25 .

[0041] Specifically, the pole shoes 25 and the permanent magnets 5 are arranged alternately along the radial direction of the turntable 13, and the pole teeth 24 are arranged on the pole shoes 25. The space between the pole teeth 24 and the turntable 13 is filled with magnetic liquid. The permanent magnets 5, the upper plate 12, the bottom plate 7 and the turntable 13 together constitute a closed magnetic circuit, and a non-uniform magnetic field with alternating strong and weak magnetic fields is generated in the tooth-shaped gaps of the pole teeth 24, which tightly absorbs the magnetic liquid, forming an end face magnetic liquid sealing structure arranged radially along the turntable 13 and composed of concentric magnetic liquid "O"-shaped sealing rings.

[0042] At the same time, the upper plate 12 and the bottom plate 7 are respectively connected to the upper and lower ends of the spacer 9 by the first cylindrical head screw 11 to form a rotating cavity for accommodating the turntable 13, and the other end face of the bottom plate 7 is connected to the mounting surface. When in the working state, the turntable 13 rotates in the rotating cavity, and the rotating cavity can also isolate the formed end face magnetic liquid sealing structure from the external environment. The contact surfaces of the upper plate 12 and the bottom plate 7 with the spacer 9 are respectively provided with a second O-ring 8 to prevent the medium from leaking along the gap between the upper plate 12 and the bottom plate 7 and the spacer 9, and the bottom plate 7 is fixedly connected to the first mounting plate 26 by fasteners, and a first O-ring 4 is provided between the bottom plate 7 and the first mounting plate 26 to prevent the medium from leaking from the gap between the bottom plate 7 and the first mounting plate 26.

[0043] In some embodiments, in order to prevent the permanent magnet 5 from being driven to rotate and generating friction, a pole shoe spacer 6 is provided between the permanent magnet 5 and the turntable 13 , and the pole shoe spacer 6 is used to isolate the permanent magnet 5 from the turntable 13 .

[0044] In some embodiments, in order to ensure that the sealing device can withstand certain radial loads and axial loads, a bearing 10 is arranged between the turntable 13 and the spacer 9, the inner ring of the bearing 10 is connected to the outer end of the turntable 13, the outer ring of the bearing 10 is connected to the inner end of the spacer 9, and bearing baffles 14 are respectively arranged at both ends of the contact surface between the inner ring of the bearing and the turntable 13. The bearing baffles 14 are threadedly tightened by a second cylindrical head screw 15. By fixing the turntable 13 and the bearing 10, it is ensured that the inner ring of the bearing can rotate with the turntable 13.

[0045] The specific implementation methods described above further illustrate the purpose, technical solutions and beneficial effects of the utility model in detail. It should be understood that the above description is only the specific implementation method of the utility model and is not used to limit the protection scope of the utility model. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the utility model should be included in the protection scope of the utility model.

Claims

1. A self-compensating sealing device, characterized in that: include: A sealing assembly (1), the sealing assembly (1) comprising a driving sleeve assembly and a fixing structure arranged outside the driving sleeve assembly, the driving sleeve assembly tightly embraces the rotating shaft and rotates synchronously with the rotating shaft; A bellows assembly (2), one end of the bellows assembly (2) is connected to the fixed structure of the sealing assembly (1), and the other end of the bellows assembly (2) is fixedly connected to the mounting surface.

2. A self-compensating sealing device according to claim 1, characterized in that: The sealing assembly (1) further comprises a rotating disk (13), the rotating disk (13) being connected to the driving sleeve assembly and extending radially along the rotating shaft, and the rotating disk (13) is provided with a first magnetic liquid seal and a second magnetic liquid seal at the upper and lower ends thereof respectively; Wherein, an end surface magnetic liquid sealing structure in a radial array along the rotation axis is formed between the first magnetic liquid sealing component and the second magnetic liquid sealing component and the rotating disk (13).

3. A self-compensating sealing device according to claim 2, characterized in that: The drive sleeve assembly comprises a clamping sleeve (20) and a drive sleeve (22), the lower end of the clamping sleeve (20) is connected to the drive sleeve (22), the drive sleeve (22) is connected to the turntable (13) via a third cylindrical head screw (17), and the outer end of the clamping sleeve (20) is clamped to the rotating shaft via a locking sleeve.

4. A self-compensating sealing device according to claim 3, characterized in that: The axial cross section of the expansion sleeve (20) is a trapezoidal shape protruding in the radial direction, and the locking sleeve comprises a first locking sleeve (18) and a second locking sleeve (21); The first locking sleeve (18) and the second locking sleeve (21) are respectively in contact with the two trapezoidal inclined surfaces of the expansion sleeve (20), and a fourth cylindrical head screw (19) is threadedly connected between the first locking sleeve (18) and the second locking sleeve (21), and the second locking sleeve (21) moves longitudinally under the threaded engagement of the fourth cylindrical head screw (19).

5. A self-compensating sealing device according to claim 3, characterized in that: A plurality of groups of fourth O-rings (23) are arranged between the drive sleeve (22) and the outer wall of the rotating shaft, and the plurality of groups of fourth O-rings (23) are arranged in an axial array. A third O-ring (16) is arranged between the drive sleeve (22) and the rotating disk (13).

6. A self-compensating sealing device according to claim 2, characterized in that: The fixing structure comprises an upper plate (12) and a bottom plate (7), wherein the upper plate (12) and the bottom plate (7) are respectively connected to the upper and lower ends of the spacer (9) and form a rotating cavity for accommodating the turntable (13), and the contact surfaces of the upper plate (12) and the bottom plate (7) with the spacer (9) are respectively provided with a second O-ring (8).

7. A self-compensating sealing device according to claim 6, characterized in that: The first magnetic liquid seal and the second magnetic liquid seal both comprise permanent magnets (5) and pole shoes (25), and the pole shoes (25) and the permanent magnets (5) are arranged in an alternating array along the radial direction of the rotating disk (13).

8. A self-compensating sealing device according to claim 7, characterized in that: A pole shoe spacer (6) is provided between the permanent magnet (5) and the rotating disk (13).

9. A self-compensating sealing device according to claim 6, characterized in that: A bearing (10) is arranged between the turntable (13) and the spacer (9), the inner ring of the bearing (10) is connected to the outer end of the turntable (13), and the outer ring of the bearing (10) is connected to the inner end of the spacer (9).

10. A self-compensating sealing device according to claim 9, characterized in that: Bearing baffles (14) are respectively provided at both ends of the contact surface between the inner ring of the bearing (10) and the turntable (13), and the bearing baffles (14) are screwed together by a second cylindrical head screw (15).

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