Magnetic liquid sealing device

Abstract

The utility model discloses a magnetic liquid sealing device which comprises a driving sleeve assembly and a rotating disc, the driving sleeve assembly tightly holds a rotating shaft and synchronously rotates along with the rotating shaft, the rotating disc is connected with the driving sleeve assembly and extends in the radial direction of the rotating shaft, and a first magnetic liquid sealing piece and a second magnetic liquid sealing piece are arranged at the upper end and the lower end of the rotating disc respectively. End face magnetic liquid sealing structures arrayed in the radial direction of the rotating shaft are formed between the first magnetic liquid sealing piece and the rotating disc and between the second magnetic liquid sealing piece and the rotating disc. The first magnetic liquid sealing piece and the second magnetic liquid sealing piece are arranged at the upper end and the lower end of the rotating disc in the radial direction of the rotating shaft respectively, and the end face magnetic liquid sealing structure is formed between the first magnetic liquid sealing piece and the rotating disc and between the second magnetic liquid sealing piece and the rotating disc. The purposes of saving axial space, reasonably using radial space and guaranteeing sealing reliability are achieved.

Description

Technical Field

[0001] The utility model relates to the technical field of sealing, in particular to a magnetic liquid 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] The current rotating shaft magnetic liquid seal structure mostly adopts the arrangement mode that the bearing is placed on the outside of the magnetic liquid seal pair and a sleeve is arranged between the bearing and the seal pair. This is acceptable for the situation where the axial dimension space is relatively abundant and the radial dimension is small. However, with the increasing application of magnetic liquid seal technology, it is found that in many cases, the arrangement of placing the bearings on both sides of the magnetic liquid seal pair cannot be adopted due to the limitation of the axial dimension.

[0005] Therefore, how to make a magnetic liquid sealing device suitable for a limited axial length and capable of ensuring both reliable operation and reliable sealing has become a problem that needs to be solved at present. Utility Model Content

[0006] The utility model aims to provide a magnetic liquid sealing device, by arranging a first magnetic liquid seal and a second magnetic liquid seal radially along the rotating shaft at the upper and lower ends of a rotating disk respectively, and forming an end face magnetic liquid sealing structure between the first magnetic liquid seal and the second magnetic liquid seal and the rotating disk, so as to achieve the purpose of saving axial space, rationally using radial space and ensuring the reliability of sealing.

[0007] The utility model is realized by the following technical solutions:

[0008] A magnetic liquid sealing device, comprising:

[0009] A driving sleeve assembly, wherein the driving sleeve assembly is tightly attached to the rotating shaft and rotates synchronously with the rotating shaft;

[0010] A turntable, the turntable is connected to the drive sleeve assembly and extends radially along the rotating shaft, and a first magnetic liquid seal and a second magnetic liquid seal are respectively provided at upper and lower ends of the turntable;

[0011] Wherein, an end surface magnetic liquid sealing structure in a radial array along the rotating shaft is formed between the first magnetic liquid sealing component and the second magnetic liquid sealing component and the rotating disk.

[0012] 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.

[0013] 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.

[0014] 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;

[0015] 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.

[0016] 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.

[0017] As a further technical solution of the magnetic liquid sealing device, the first magnetic liquid seal includes an upper plate, and the second magnetic liquid seal includes a bottom plate. 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 second O-rings to prevent the medium from leaking along the gap between the upper plate and the bottom plate and the spacer.

[0018] 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.

[0019] 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.

[0020] 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.

[0021] 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.

[0022] As a further technical solution of the magnetic liquid sealing device, the bottom plate is connected to the mounting surface, and a first O-ring is arranged between the bottom plate and the mounting surface to prevent the medium from leaking from the gap between the bottom plate and the mounting surface.

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

[0024] The utility model provides a magnetic liquid sealing device, comprising a driving sleeve assembly and a rotating disk. The rotating disk rotates synchronously with a rotating shaft through the driving sleeve assembly, and the outer end of the rotating disk extends radially along the rotating shaft. At the same time, a first magnetic liquid sealing component and a second magnetic liquid sealing component are respectively arranged radially along the rotating shaft at the upper and lower ends of the rotating disk. In a working state, the driving sleeve assembly drives the rotating disk to rotate, and the first magnetic liquid sealing component, the second magnetic liquid sealing component and the rotating disk form a closed magnetic circuit, and a non-uniform magnetic field with alternating strong and weak strengths is generated in a tooth-shaped gap, so that the magnetic liquid is tightly attracted, so that an end-face magnetic liquid sealing structure is formed between the first magnetic liquid sealing component, the second magnetic liquid sealing component and the rotating disk. The structure is compact, saves axial space, and reasonably uses radial space, so as to avoid the situation that the sealing device cannot be arranged due to the limitation of the axial size. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] 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:

[0026] Figure 1 It is a three-dimensional structural schematic diagram of the utility model;

[0027] Figure 2 It is a cross-sectional structural schematic diagram of the utility model;

[0028] Figure 3 for Figure 2 Schematic diagram of the enlarged structure marked A in FIG.

[0029] Marks and corresponding parts names in the attached drawings:

[0030] 1-first O-ring; 2-permanent magnet; 3-pole shoe spacer; 4-bottom plate; 5-second O-ring; 6-spacer; 7-bearing; 8-first cylindrical head screw; 9-upper plate; 10-turntable; 11-bearing baffle; 12-second cylindrical head screw; 13-third O-ring; 14-third cylindrical head screw; 15-first locking sleeve; 16-fourth cylindrical head screw; 17-expansion sleeve; 18-second locking sleeve; 19-drive sleeve; 20-fourth O-ring; 21-pole tooth; 22-pole shoe. DETAILED DESCRIPTION

[0031] 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.

[0032] Example

[0033] This embodiment provides a magnetic liquid sealing device, such as Figure 1-Figure 3 As shown, it includes a driving sleeve assembly and a turntable 10.

[0034] Among them, Figure 1-Figure 3 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 17 and a drive sleeve 19. The lower end of the clamping sleeve 17 is connected to the drive sleeve 19, and the drive sleeve 19 is connected to the turntable 10 through the third cylindrical head screw 14. The outer end of the clamping sleeve 17 is clamped to the rotating shaft through the locking sleeve, and the torque is transmitted to the turntable 10 through the expansion force between the clamping sleeve 17 and the rotating shaft.

[0035] Specifically, the above-mentioned expansion sleeve 17 is an annular sleeve, and the axial cross-section of the expansion sleeve 17 is a trapezoidal shape protruding in the radial direction. The circumferential side wall of the expansion sleeve 17 is evenly distributed with penetrating compensation seams, and the locking sleeve includes a first locking sleeve 15 and a second locking sleeve 18, which are respectively abutted against the two trapezoidal inclined surfaces of the expansion sleeve 17. A fourth cylindrical head screw 16 is also threadedly connected between the first locking sleeve 15 and the second locking sleeve 18. The second locking sleeve 18 moves longitudinally under the threaded engagement of the fourth cylindrical head screw 16. When the expansion sleeve 17 needs to be tightly held to the rotating shaft, it is only necessary to adjust the longitudinal displacement of the second locking sleeve 18 through the fourth cylindrical head screw 16 to adjust the expansion force between the expansion sleeve 17 and the rotating shaft.

[0036] At the same time, in order to prevent the medium from leaking along the gap between the drive sleeve 19 and the turntable 10, multiple groups of fourth O-rings 20 are arranged between the drive sleeve 19 and the outer wall of the rotating shaft. In this embodiment, two groups are arranged. The two groups of fourth O-rings 20 are arranged in an axial array, which can prevent the medium from leaking along the gap between the drive sleeve 19 and the rotating shaft. In order to further prevent the medium from leaking along the gap between the drive sleeve 19 and the turntable 10, a third O-ring 13 is arranged between the drive sleeve 19 and the turntable 10.

[0037] Please refer to Figure 1-Figure 3 As shown, the first magnetic liquid seal includes an upper plate 9 , the second magnetic liquid seal includes a bottom plate 4 , and both the first magnetic liquid seal and the second magnetic liquid seal further include a permanent magnet 2 and a pole shoe 22 .

[0038] Specifically, the pole shoes 22 and the permanent magnets 2 are arranged alternately along the radial direction of the turntable 10, and the pole teeth 21 are arranged on the pole shoes 22. The space between the pole teeth 21 and the turntable 10 is filled with magnetic liquid. The permanent magnets 2, the upper plate 9, the bottom plate 4 and the turntable 10 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 21, which tightly absorbs the magnetic liquid, forming an end face magnetic liquid sealing structure arranged radially along the turntable 10 and composed of concentric magnetic liquid "O"-shaped sealing rings.

[0039] At the same time, the upper plate 9 and the bottom plate 4 are respectively connected to the upper and lower ends of the spacer 6 by the first cylindrical head screw 8 to form a rotating cavity for accommodating the turntable 10, and the other end face of the bottom plate 4 is connected to the mounting surface. When in the working state, the turntable 10 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 9 and the bottom plate 4 with the spacer 6 are respectively provided with a second O-ring 5 for preventing the medium from leaking along the gap between the upper plate 9 and the bottom plate 4 and the spacer 6, and a first O-ring 1 is provided between the bottom plate 4 and the mounting surface to prevent the medium from leaking from the gap between the bottom plate 4 and the mounting surface.

[0040] In some embodiments, in order to prevent the permanent magnet 2 from being driven to rotate and generating friction, a pole shoe spacer 3 is provided between the permanent magnet 2 and the turntable 10 , and the pole shoe spacer 3 is used to isolate the permanent magnet 2 from the turntable 10 .

[0041] In some embodiments, in order to ensure that the sealing device can withstand certain radial loads and axial loads, a bearing 7 is arranged between the turntable 10 and the spacer 6, the inner ring of the bearing 7 is connected to the outer end of the turntable 10, the outer ring of the bearing 7 is connected to the inner end of the spacer 6, and bearing baffles 11 are respectively arranged at both ends of the contact surface between the inner ring of the bearing and the turntable 10. The bearing baffles 11 are threadedly tightened by a second cylindrical head screw 12. By fixing the turntable 10 and the bearing 7, it is ensured that the inner ring of the bearing can rotate with the turntable 10.

[0042] 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 magnetic liquid sealing device, characterized in that: include: A driving sleeve assembly, wherein the driving sleeve assembly is tightly held on the rotating shaft and rotates synchronously with the rotating shaft; A rotating disk (10), the rotating disk (10) being connected to the driving sleeve assembly and extending radially along the rotating shaft, and a first magnetic liquid seal and a second magnetic liquid seal being respectively provided at upper and lower ends of the rotating disk (10); 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 (10).

2. A magnetic liquid sealing device according to claim 1, characterized in that: The drive sleeve assembly comprises a clamping sleeve (17) and a drive sleeve (19), the lower end of the clamping sleeve (17) is connected to the drive sleeve (19), the drive sleeve (19) is connected to the turntable (10) via a third cylindrical head screw (14), and the outer end of the clamping sleeve (17) is clamped to the rotating shaft via a locking sleeve.

3. A magnetic liquid sealing device according to claim 2, characterized in that: The axial cross-section of the expansion sleeve (17) is a trapezoidal shape protruding in the radial direction, and the locking sleeve comprises a first locking sleeve (15) and a second locking sleeve (18); The first locking sleeve (15) and the second locking sleeve (18) are respectively in contact with the two trapezoidal inclined surfaces of the expansion sleeve (17), and a fourth cylindrical head screw (16) is threadedly connected between the first locking sleeve (15) and the second locking sleeve (18), and the second locking sleeve (18) moves longitudinally under the threaded engagement of the fourth cylindrical head screw (16).

4. A magnetic liquid sealing device according to claim 2, characterized in that: A plurality of groups of fourth O-rings (20) are arranged between the drive sleeve (19) and the outer wall surface of the rotating shaft, and the plurality of groups of fourth O-rings (20) are arranged in an axial array. A third O-ring (13) is arranged between the drive sleeve (19) and the rotating disk (10).

5. A magnetic liquid sealing device according to claim 1, characterized in that: The first magnetic liquid seal comprises an upper plate (9), and the second magnetic liquid seal comprises a bottom plate (4). The upper plate (9) and the bottom plate (4) are respectively connected to the upper and lower ends of the spacer (6) to form a rotating cavity for accommodating the turntable (10). The contact surfaces of the upper plate (9) and the bottom plate (4) with the spacer (6) are respectively provided with a second O-ring (5).

6. A magnetic liquid sealing device according to claim 5, characterized in that: The first magnetic liquid seal and the second magnetic liquid seal both further include permanent magnets (2) and pole shoes (22), wherein the pole shoes (22) and the permanent magnets (2) are arranged in an alternating array along the radial direction of the rotating disk (10).

7. A magnetic liquid sealing device according to claim 6, characterized in that: A pole shoe spacer (3) is provided between the permanent magnet (2) and the rotating disk (10).

8. A magnetic liquid sealing device according to claim 5, characterized in that: A bearing (7) is provided between the rotating disk (10) and the spacer (6); an inner ring of the bearing (7) is connected to an outer end of the rotating disk (10), and an outer ring of the bearing (7) is connected to an inner end of the spacer (6).

9. A magnetic liquid sealing device according to claim 8, characterized in that: Bearing baffles (11) are respectively provided at both ends of the contact surface between the inner ring of the bearing (7) and the turntable (10), and the bearing baffles (11) are screwed together by a second cylindrical head screw (12).

10. A magnetic liquid sealing device according to claim 5, characterized in that: The base plate (4) is connected to the mounting surface, and a first O-ring (1) is arranged between the base plate (4) and the mounting surface.

Images