WO2020006712A1 - Magnetic fluid sealing device having corrugated tube assisting in sealing - Google Patents

Abstract

A magnetic fluid sealing device (10) having a corrugated tube assisting in sealing, comprising: a seal housing (100), a cylindrical pin sleeve (200), and a corrugated tube assembly (300). The corrugated tube assembly (300) comprises a corrugated tube (310), a corrugated tube upper-end flange (320), and a corrugated tube lower-end flange (330). The corrugated tube (310) is separately welded to the corrugated tube upper-end flange (320) and the corrugated tube lower-end flange (330). A first sealing ring (321) is mounted in a sealing groove of the corrugated tube upper-end flange (320). A second sealing ring (331) is mounted in a sealing groove of the corrugated tube lower-end flange (330). The corrugated tube upper-end flange (320) is attached to the seal housing (100). Preset gaps are reserved between the corrugated tube lower-end flange (330) and the cylindrical pin sleeve (200) and between the corrugated tube lower-end flange (330) and the seal housing (100).

Description

Bellows-assisted magnetic liquid sealing device Technical field

The invention relates to the technical field of mechanical engineering sealing, in particular to a magnetic liquid sealing device for auxiliary sealing of a bellows.

Background technique

Magnetic liquid seals have many advantages such as zero leakage, low cost, and long life, so they are widely used. However, in practical applications, especially at high speeds, due to limited mounting accuracy and machining accuracy, the shaft has a large runout in the radial direction, and the gap between the magnetic liquid seal and the shaft is small, which is extremely likely to occur. Rubbing and fatigue. These phenomena have seriously affected the service life of the magnetic liquid seal, and also reduced the reliability of the seal.

In the related art, a magnetic liquid sealing device, such as a magnetic liquid sealing device with a variable sealing gap, adjusts the sealing gap of the magnetic liquid seal by adjusting the position of the trapezoidal movable magnetic block to reduce the friction between the shaft and the seal. However, it cannot solve the problem of seal failure caused by the periodic change of the seal gap when the shaft is beating, and the device uses active control, and cannot adaptively control the gap during work.

Summary of the invention

The present invention aims to solve at least one of the technical problems in the related technology to a certain extent.

For this reason, the purpose of the present invention is to propose a magnetic liquid sealing device for auxiliary sealing of a corrugated tube. The device can use the elasticity of the corrugated tube to play a buffering role when a radial runout of the rotating shaft occurs, and effectively solve the problem due to the rotating shaft under high-speed working conditions. The seal is damaged due to the runout of the pump.

In order to achieve the above object, an embodiment of one aspect of the present invention proposes a magnetic liquid sealing device for auxiliary sealing of a bellows, including: a seal housing; a cylindrical pin sleeve, the cylindrical pin sleeve being used for gap control and positioning; A bellows, a bellows upper flange and a bellows lower flange, the bellows are welded to the bellows upper flange and the bellows lower flange, respectively, and the bellows upper flange seal groove is installed in the bellows A first seal ring, a second seal ring is installed in the flange groove at the lower end of the bellows to form a bellows assembly, wherein the upper flange of the bellows is abutted with the seal housing, and the bellows A preset gap is left between the lower end flange, the cylindrical pin sleeve, and the seal housing.

The corrugated tube-assisted magnetic liquid sealing device according to the embodiment of the present invention uses a corrugated tube to perform an auxiliary seal on the basis of the magnetic liquid seal. The corrugated tube auxiliary seal is adopted, which can use the elasticity of the corrugated tube when the shaft rotates radially. To the buffer effect, effectively solve the seal damage caused by the runout of the shaft under high-speed conditions.

In addition, the bellows-assisted magnetic liquid sealing device according to the above embodiment of the present invention may also have the following additional technical features:

Further, in an embodiment of the present invention, the preset gap is 0.1 mm to 2 mm.

Further, in an embodiment of the present invention, the upper flange of the bellows is fixedly connected to the seal housing by bolts, the lower flange of the bellows is machined with threaded holes, and is connected to the seal cavity through threads. The shell is connected and fixed.

Further, in an embodiment of the present invention, it further includes: a first rolling bearing and a second rolling bearing, the first rolling bearing is installed in an inner hole of the seal housing, and passes through one side of a shaft shoulder of the rotating shaft and the other The inner boss of the seal housing is positioned, and the second rolling bearing is installed in the inner hole of the seal housing and is in contact with the other side of the shaft shoulder of the rotating shaft.

Further, in an embodiment of the present invention, it further includes: a magnetic liquid seal assembly, the magnetic liquid seal assembly includes a first-level boot, a second-level boot, a third-level boot, a third seal ring, and a fourth seal. Ring, fifth seal ring, first permanent magnet and second permanent magnet, the third seal ring is installed in a sealing groove on the outer cylindrical surface of the first-stage shoe, and the fourth seal ring is installed in the first In the sealing groove on the outer cylindrical surface of the second-stage boot, the fifth seal ring is installed in the sealing groove on the outer cylindrical surface of the third-stage boot, and the first permanent magnet is installed on the lower end surface of the first-stage shoe. The second permanent magnet is installed on the lower end surface of the second-stage shoe.

Further, in an embodiment of the present invention, it further comprises: a magnetic isolation positioning sleeve, the magnetic isolation positioning sleeve is installed on the lower end surface of the second rolling bearing, and the magnetic liquid seal assembly is installed under the magnetic isolation positioning sleeve. On the end face.

Further, in an embodiment of the present invention, a cylindrical pin is installed in the pin hole of the cylindrical pin sleeve, and the upper end surface of the inner boss of the cylindrical pin sleeve is close to the lower end surface of the third-stage boot. contact.

Further, in an embodiment of the present invention, it further comprises: a gland, a circular hole on an upper end surface of the gland catches the cylindrical pin, presses a lower end surface of the cylindrical pin sleeve, and is connected by a thread It is connected and fixed with the lower end flange of the bellows, wherein a preset radial gap is left between the cylindrical pin and the gland.

Further, in an embodiment of the present invention, the preset radial gap is 2 mm to 6 mm.

Further, in an embodiment of the present invention, the first-level boots, the second-level boots, and the third-level boots are all made of magnetically conductive material, and the first permanent magnet, the The second permanent magnet is a RuFeB permanent magnet.

Additional aspects and advantages of the present invention will be given in part in the following description, part of which will become apparent from the following description, or be learned through the practice of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and / or additional aspects and advantages of the present invention will become apparent and easily understood from the following description of the embodiments with reference to the accompanying drawings, in which:

FIG. 1 is a schematic structural diagram of a magnetic liquid sealing device for a bellows-assisted sealing according to an embodiment of the present invention; FIG.

FIG. 2 is an enlarged schematic diagram at a position A in FIG. 1 according to an embodiment of the present invention.

Reference sign description:

Bellows-assisted magnetic liquid sealing device 10, seal housing 100, cylindrical pin sleeve 200, cylindrical pin 210, bellows assembly 300, bellows 310, bellows upper end flange 320, first seal ring 321, ripple Lower pipe flange 330, second sealing ring 331, first rolling bearing 400, second rolling bearing 500, magnetic liquid seal assembly 600, first-stage boot 610, second-stage boot 620, third-stage boot 630, third-sealing ring 640, a fourth sealing ring 650, a fifth sealing ring 660, a first permanent magnet 670, a second permanent magnet 680, a magnetic isolation positioning sleeve 700, a gland 800, and a magnetic liquid 900.

detailed description

Hereinafter, embodiments of the present invention will be described in detail. Examples of the embodiments are shown in the drawings, wherein the same or similar reference numerals indicate the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the drawings are exemplary and are intended to explain the present invention, but should not be construed as limiting the present invention.

Hereinafter, a magnetic liquid sealing device of a bellows-assisted seal according to an embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is a schematic structural diagram of a magnetic liquid sealing device with a bellows-assisted seal according to an embodiment of the present invention.

As shown in FIG. 1, the bellows-assisted magnetic liquid sealing device 10 includes a seal housing 100, a cylindrical pin sleeve 200, and a bellows assembly 300.

Among them, the seal housing 100. The cylindrical pin sleeve 200 is used for clearance control and positioning. The bellows 310 are welded to the bellows upper flange 320 and the bellows lower flange 330, respectively. A first seal ring 321 is installed in the seal groove of the bellows upper flange 320, and a second seal is installed in the bellows flange 330. The seal ring 331 forms a bellows assembly 300, in which the upper end flange 320 of the bellows is attached to the seal housing 100, and the lower end flange 330 of the bellows is connected to the cylindrical pin sleeve 200 and the seal housing 100. Set the gap. The device 10 of the embodiment of the present invention uses a corrugated tube auxiliary seal, which can use the elasticity of the corrugated tube to cushion the shaft when the shaft pulsates radially, thereby effectively solving the seal damage caused by the shaft pulsation under high-speed conditions. problem.

It can be understood that the embodiment of the present invention uses a corrugated tube 310 for auxiliary sealing on the basis of a magnetic liquid seal, that is, the seal housing 100 and the upper end flange 320 of the corrugated tube are bolted, and the lower end is connected to the lower end flange 330 of the corrugated tube. There is a certain gap between them. At the same time, the cylindrical pin, the No. 1 cylindrical pin sleeve and the No. 2 cylindrical pin sleeve are used for clearance control and positioning, which effectively solves the bounce of the rotating shaft and collision with the seal at high speeds. As a result, the service life of the sealing device is shortened and the sealing performance is reduced.

Specifically, as shown in FIG. 1, the bellows 310 is welded to the bellows upper end flange 320 and the bellows lower end flange 330 respectively. The first seal ring 321 is installed in the seal groove of the bellows upper end flange 320 and the second The sealing ring 331 is installed in the sealing groove of the lower end flange 330 of the bellows, and constitutes the bellows assembly 300. There is a gap between the cylindrical pin sleeve 200, the seal housing 100 and the bellows lower flange 330 in the radial direction and the axial direction, that is, a gap is left between the cylindrical pin sleeve 200 and the bellows lower flange 330. The seal A gap is left between the casing 100 and the lower end flange 330 of the bellows.

Further, in one embodiment of the present invention, the preset gap is 0.1 mm to 2 mm.

Further, in one embodiment of the present invention, the upper end flange 320 of the corrugated pipe is fixedly connected to the seal housing 100 through bolts, and the lower end flange 330 of the corrugated pipe is machined with threaded holes, which can be connected to the sealed cavity housing 100 through threads Connect and secure.

Further, in an embodiment of the present invention, the device 10 of the embodiment of the present invention further includes a first rolling bearing 400 and a second rolling bearing 500. The first rolling bearing 400 is installed in the inner hole of the seal housing 100, and is positioned with the inner boss of the seal housing 100 by one side of the shaft shoulder of the rotating shaft. The second rolling bearing 500 is installed in the seal housing 100. Inside the inner hole and in contact with the other side of the shaft shoulder of the shaft.

Further, in an embodiment of the present invention, the device 10 of the embodiment of the present invention further includes a magnetic liquid sealing assembly 600. The magnetic liquid seal assembly 600 includes a first-stage boot 610, a second-stage boot 620, a third-stage boot 630, a third seal 640, a fourth seal 650, a fifth seal 660, a first permanent magnet 670, and The second permanent magnet 680, the third seal ring 640 are installed in the seal groove on the outer cylindrical surface of the first-stage shoe 610, the fourth seal ring 650 is installed in the seal groove on the outer cylindrical surface of the second-stage shoe 620, and the fifth seal ring 660 is installed in the sealing groove on the outer cylindrical surface of the third-stage shoe 630, the first permanent magnet 670 is installed on the lower end surface of the first-stage shoe 610, and the second permanent magnet 680 is installed on the lower end surface of the second-stage shoe 620.

Further, in an embodiment of the present invention, the first-level boots 610, the second-level boots 620, and the third-level boots 630 can be selected from magnetic permeability materials, and the first permanent magnet 670 and the second permanent magnet 680 You can choose Ru-Fe-B permanent magnet.

It can be understood that the first-level boots 610, the second-level boots 620, and the third-level boots 630 can be selected from materials with good magnetic permeability, such as electric pure iron. Of course, regarding the materials with magnetic permeability and permanent magnets, A person skilled in the art may make a selection according to actual conditions. In the embodiment of the present invention, only electric pure iron and Ru-Fe-B permanent magnets are used as examples, and no specific limitation is made herein.

Further, in an embodiment of the present invention, the device 10 of the embodiment of the present invention further includes: a magnetically-isolated positioning sleeve 700. The magnetically-isolated positioning sleeve 700 is installed on the lower end surface of the second rolling bearing 500, and the magnetic liquid seal assembly 500 is installed on the lower-end surface of the magnetically-isolated positioning sleeve 700.

Further, in an embodiment of the present invention, as shown in FIG. 2, a cylindrical pin 210 is installed in the pin hole of the cylindrical pin sleeve 200, and the upper end surface of the inner boss of the cylindrical pin sleeve 200 and the third-stage boot 630 The lower end face is in close contact.

Further, in an embodiment of the present invention, the device 10 according to the embodiment of the present invention further includes: a gland 800. The circular hole on the upper end surface of the gland 800 buckles the cylindrical pin 210, presses the lower end surface of the cylindrical pin sleeve 200, and connects and fixes the lower end flange 330 of the corrugated pipe through a threaded connection. A predetermined radial gap is left between the covers 800.

In one embodiment of the present invention, the preset radial gap may be 2 mm to 6 mm.

Further, the device 10 according to the embodiment of the present invention further includes: a magnetic liquid 900. Among them, the type of the magnetic liquid 900 can be selected based on the sealing gas.

It should be noted that the process design of the magnetic liquid seal assembly, the bellows assembly, and the shaft assembly can be selected according to the specific sealing conditions, and is not specifically limited here.

To sum up, the bellows is welded with the upper flange of the bellows and the lower flange of the bellows. The upper flange of the bellows fits the seal housing, and the gap between the lower flange of the bellows and the cylindrical pin sleeve and the seal housing is left. . In actual work, the lower flange of the bellows is connected to the fixed platform by a thread and cannot be moved, and the seal housing connected to the upper flange of the bellows is connected to the rotating shaft through a rolling bearing, which will bounce along with the radial direction of the rotating shaft. Due to the radial clearance between the seal housing, the cylindrical pin and the cylindrical pin sleeve assembly in the radial direction and the lower flange of the bellows, the rigid impact of the seal can be avoided to cause damage, and due to the elasticity of the bellows It can provide resilience when the shaft rotates periodically and radially, and keep the gap of the entire seal basically stable. In addition, the bellows also has good sealing performance and can be used as an auxiliary seal for the entire seal.

According to the corrugated tube auxiliary sealing magnetic liquid sealing device provided by the embodiment of the present invention, the corrugated tube is used for auxiliary sealing on the basis of the magnetic liquid seal, and the corrugated tube auxiliary sealing is adopted, which can use the corrugated tube when the shaft rotates radially. Elasticity acts as a buffer and effectively solves the problem of seal damage caused by the runout of the shaft under high-speed conditions.

In addition, the terms "first" and "second" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the present invention, the meaning of "a plurality" is at least two, for example, two, three, etc., unless it is specifically and specifically defined otherwise.

In the description of this specification, the description with reference to the terms “one embodiment”, “some embodiments”, “examples”, “specific examples”, or “some examples” and the like means specific features described in conjunction with the embodiments or examples , Structures, materials, or features are included in at least one embodiment or example of the invention. In this specification, the schematic expressions of the above terms are not necessarily directed to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples. In addition, without any contradiction, those skilled in the art may combine and combine different embodiments or examples and features of the different embodiments or examples described in this specification.

Although the embodiments of the present invention have been shown and described above, it can be understood that the above embodiments are exemplary and should not be construed as limitations on the present invention. Those skilled in the art can interpret the above within the scope of the present invention. Embodiments are subject to change, modification, substitution, and modification.

Claims (10)

1. A bellows-assisted magnetic liquid sealing device is characterized in that it includes:

   Seal housing

   Cylindrical pin sleeve for clearance control and positioning; and

   A bellows, a bellows upper flange and a bellows lower flange, the bellows are welded to the bellows upper flange and the bellows lower flange, respectively, and the bellows upper flange seal groove is installed in the bellows A first seal ring, a second seal ring is installed in the flange groove at the lower end of the bellows to form a bellows assembly, wherein the upper flange of the bellows is abutted with the seal housing, and the bellows A preset gap is left between the lower end flange, the cylindrical pin sleeve, and the seal housing.
2. The magnetic liquid sealing device according to claim 1, wherein the preset gap is 0.1 mm to 2 mm.
3. The magnetic liquid sealing device for auxiliary sealing of a corrugated tube according to claim 1, wherein the upper end flange of the corrugated tube is fixedly connected to the seal housing by bolts, and the lower end flange of the corrugated tube is threaded The hole is connected and fixed with the sealed cavity shell through a thread.
4. The magnetic liquid sealing device for auxiliary sealing of a bellows according to claim 1, further comprising:

   A first rolling bearing and a second rolling bearing, wherein the first rolling bearing is installed in an inner hole of the seal housing, and is positioned with an inner boss of the seal housing through one side of a shaft shoulder of a rotating shaft; Two rolling bearings are installed in the inner hole of the seal housing and are in contact with the other side of the shaft shoulder of the rotating shaft.
5. The magnetic liquid sealing device for auxiliary sealing of a bellows according to claim 1, further comprising:

   Magnetic liquid seal assembly, the magnetic liquid seal assembly includes a first-level boot, a second-level boot, a third-level boot, a third seal, a fourth seal, a fifth seal, a first permanent magnet, and a second permanent magnet. A magnet, the third seal ring is installed in the seal groove on the outer cylindrical surface of the first-stage shoe, the fourth seal ring is installed in the seal groove on the outer cylindrical surface of the second-stage shoe, and the fifth A sealing ring is installed in a sealing groove on the outer cylindrical surface of the third-stage boot, the first permanent magnet is installed on a lower end surface of the first-stage boot, and the second permanent magnet is installed on a lower end-surface of the second-stage boot.
6. The bellows-assisted magnetic liquid sealing device according to claim 4 and 5, further comprising:

   The magnetic isolation positioning sleeve is installed on the lower end surface of the second rolling bearing, and the magnetic liquid seal assembly is installed on the lower end surface of the magnetic isolation positioning sleeve.
7. The magnetic liquid sealing device for auxiliary sealing of a bellows according to claim 5, wherein a cylindrical pin is installed in a pin hole of the cylindrical pin sleeve, and an upper end surface of an inner boss of the cylindrical pin sleeve and The lower end face of the third-level boot is in close contact.
8. The bellows-assisted magnetic liquid sealing device according to claim 7, further comprising:

   A gland, the circular hole on the upper end of the gland fastens the cylindrical pin, presses the lower end of the cylindrical pin sleeve, and connects and fixes the flange with the lower end of the bellows through a screw connection. A preset radial gap is left between the cylindrical pin and the gland.
9. The magnetic liquid sealing device according to claim 8, wherein the preset radial gap is 2 mm to 6 mm.
10. The bellows-assisted magnetic liquid sealing device according to claim 5, wherein,

    The first-level boots, the second-level boots, and the third-level boots are all made of magnetically permeable materials, and the first permanent magnet and the second permanent magnet are made of RuFeB permanent magnets.

Images