CN113154043A

CN113154043A - Sealing device combining mechanical seal and magnetic liquid seal

Info

Publication number: CN113154043A
Application number: CN202110426387.7A
Authority: CN
Inventors: 李德才; 任思杰; 韩鹏栋; 李英松
Original assignee: Tsinghua University
Current assignee: Tsinghua University
Priority date: 2021-04-20
Filing date: 2021-04-20
Publication date: 2021-07-23
Anticipated expiration: 2041-04-20
Also published as: CN113154043B

Abstract

The invention relates to the technical field of mechanical engineering sealing, in particular to a sealing device combining mechanical sealing and magnetic liquid sealing. The sealing device comprises a shell, a rotating shaft and a first sealing assembly, wherein the first sealing assembly comprises a static ring, a rotating ring, a first pole shoe, a second pole shoe and a first permanent magnet. The pivot passes the stationary ring, and stationary ring and casing seal cooperation or stationary ring link to each other with the casing have along the first annular seal face of inside and outside direction extension on the stationary ring. The rotating ring comprises a rotating ring main body and a first ring body, the rotating ring main body is connected with the rotating shaft, and the first ring body is in sealing fit with the first annular sealing surface. The first pole shoe is sleeved on the outer side of the rotating shaft, the second pole shoe is sleeved on the outer side of the first pole shoe, each of the first pole shoe and the second pole shoe is spaced from the first annular sealing surface in the axial direction of the rotating shaft to form a first sealing gap, and the first sealing gap is filled with magnetic liquid. The sealing device provided by the embodiment of the invention has the advantage of being suitable for various working conditions.

Description

Sealing device combining mechanical seal and magnetic liquid seal

Technical Field

The invention relates to the technical field of mechanical engineering sealing, in particular to a sealing device combining mechanical sealing and magnetic liquid sealing.

Background

Magnetic liquid seals are widely used in more and more industries as a sealing method capable of achieving 'zero leakage'. The working principle is that under the action of magnetic field generated by permanent magnet, the magnetic liquid placed between rotating shaft and gap of top end of pole tooth is concentrated to form an O-shaped ring, so that the gap channel is blocked to attain the goal of sealing. However, the magnetic liquid seal has limited working conditions due to the material property and pressure resistance of the magnetic liquid, which are limited by the magnetic force of the permanent magnet, the property of the magnetic liquid, the number of pole teeth, and the like.

Disclosure of Invention

The present invention is directed to solving, at least to some extent, one of the technical problems in the related art.

Therefore, the embodiment of the invention provides a sealing device which is applicable to mechanical sealing and magnetic liquid sealing combination under various working conditions.

The sealing device combining the mechanical seal and the magnetic liquid seal according to the embodiment of the invention comprises:

a housing defining a chamber;

the rotating shaft is rotatably arranged in the cavity; and

a first seal assembly, the first seal assembly comprising:

the rotating shaft penetrates through the static ring, the static ring is in sealing fit with the shell or is connected with the shell, the static ring and the rotating shaft are arranged at intervals along the inner and outer directions, and a first annular sealing surface extending along the inner and outer directions is arranged on the static ring;

the rotating ring comprises a rotating ring main body and a first ring body connected with the rotating ring main body, the rotating ring main body is sleeved on the outer side of the rotating shaft and connected with the rotating shaft, and the first ring body is in sealing fit with the first annular sealing surface;

a first pole piece and a second pole piece, the first pole piece is sleeved on the outer side of the rotating shaft and connected with the rotating ring, the second pole piece is sleeved on the outer side of the first pole piece and connected with the rotating ring, each of the first pole piece and the second pole piece is opposite to the first ring body in the inner and outer directions, each of the first pole piece and the second pole piece is positioned on the inner side or the outer side of the first ring body in the inner and outer directions, each of the first pole piece and the second pole piece is spaced from the first annular sealing surface in the axial direction of the rotating shaft to form a first sealing gap, and the first sealing gap is filled with magnetic liquid; and

the first permanent magnet is sleeved on the outer side of the first pole shoe, the second pole shoe is sleeved on the outer side of the first permanent magnet, and the first permanent magnet is provided with an N pole and an S pole which are opposite in the inner and outer directions.

The sealing device combining the mechanical seal and the magnetic liquid seal has the advantages of good sealing effect, suitability for various working conditions and the like.

In some embodiments, the rotating ring further includes a second ring body disposed at a distance from the first ring body in an inward-outward direction, the second ring body being connected to the rotating ring main body, the second ring body being in sealing engagement with the first annular sealing surface, and the first pole piece, the second pole piece, and the first permanent magnet being located between the first ring body and the second ring body in the inward-outward direction.

In some embodiments, the second ring body is located outside the first ring body in an inner-outer direction, and the first ring body is disposed spaced apart from the rotation shaft in the inner-outer direction.

In some embodiments, the rotating ring further comprises a first seal ring, wherein a first seal ring groove is formed on the inner peripheral surface of the rotating ring main body, the first seal ring is fixedly installed in the first seal ring groove, and the inner peripheral surface of the first seal ring is attached to the peripheral surface of the rotating shaft.

In some embodiments, the stationary ring is further provided with a second annular sealing surface extending in the inward-outward direction, the housing is provided with a third annular sealing surface extending in the inward-outward direction, the second annular sealing surface is arranged adjacent to the first annular sealing surface relative to the third annular sealing surface in the axial direction of the rotating shaft, a first elastic sealing ring is arranged between the second annular sealing surface and the third annular sealing surface, and the stationary ring and the housing are in sealing fit through the first elastic sealing ring.

In some embodiments, the stationary ring is further provided with a fourth annular sealing surface extending in the axial direction of the rotating shaft, the housing is further provided with a fifth annular sealing surface extending in the axial direction of the rotating shaft, the fourth annular sealing surface and the fifth annular sealing surface are arranged at intervals in the inner and outer directions, and the first elastic sealing ring is arranged between the fourth annular sealing surface and the fifth annular sealing surface.

In some embodiments, further comprising a second seal assembly, the first and second seal assemblies being disposed in spaced relation along an axial direction of the rotating shaft, the second seal assembly comprising:

each of the third pole shoe and the fourth pole shoe is sleeved outside the rotating shaft, each of the third pole shoe and the fourth pole shoe is connected with the shell, the inner circumferential surface of each of the third pole shoe and the fourth pole shoe is spaced from the circumferential surface of the rotating shaft in the inner and outer directions to form a second sealing gap, and the second sealing gap is filled with magnetic liquid; and

the second permanent magnet is sleeved on the outer side of the rotating shaft and located between the third pole shoe and the fourth pole shoe in the axial direction of the rotating shaft, and the second permanent magnet is provided with an N pole and an S pole which are opposite to each other in the axial direction of the rotating shaft.

In some embodiments, the first seal assembly is provided in plurality, and the plurality of first seal assemblies are provided at intervals along the axial direction of the rotating shaft, and the second seal assembly is located between two adjacent first seal assemblies in the axial direction of the rotating shaft.

In some embodiments, an annular protrusion is provided on an inner peripheral surface of the housing, the annular protrusion is located between two adjacent first seal assemblies in an axial direction of the rotating shaft, the second seal assembly is opposite to the annular protrusion in an inner and outer direction, an outer peripheral surface of each of the third pole piece and the fourth pole piece is connected to a peripheral surface of the annular protrusion, and a stationary ring of at least one of the two adjacent first seal assemblies is connected to the annular protrusion.

In some embodiments, the first seal assembly is provided in plurality, and the plurality of first seal assemblies are provided at intervals in the axial direction of the rotating shaft.

Drawings

Fig. 1 is a schematic structural view of a sealing device combining a mechanical seal and a magnetic liquid seal according to an embodiment of the present invention.

Fig. 2 is an enlarged view at a in fig. 1.

Fig. 3 is an enlarged view at B in fig. 1.

Fig. 4 is a schematic view of the stationary ring of fig. 1.

Fig. 5 is a schematic view of the structure of fig. 1 at the first tooth.

Reference numerals: a sealing device 100;

a housing 1; a housing main body 101; an annular projection 1011; a first end portion 1012; a second end 1013; a first end cap 102; a third annular seal surface 1021; a fifth annular sealing surface 1022; a second end cap 103; a chamber 104;

a rotating shaft 2;

a first seal assembly 3; a stationary ring 301; a first annular sealing surface 3011; a second annular sealing surface 3012; a fourth annular sealing surface 3013; a rotating ring 302; the rotating ring main body 3021; a first seal ring groove 30211; a first ring body 3022; a second ring body 3023; a first pole piece 303; a first pole tooth 3031; a second seal ring 3032; a second pole piece 304; the second pole tooth 3041; a third seal ring 3042; a first permanent magnet 305; a first elastomeric seal ring 306;

a second seal assembly 4; a third pole piece 401; the third pole teeth 4011; a fourth seal ring 4012; a fourth pole shoe 402; fourth pole tooth 4021; a fifth seal 4022; a second permanent magnet 403;

a first seal ring 5;

a clamp spring 6;

a magnetic liquid 10.

Detailed Description

Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings. The embodiments described below with reference to the drawings are illustrative and intended to be illustrative of the invention and are not to be construed as limiting the invention.

As shown in fig. 1 to 5, a sealing device 100 (hereinafter, referred to as a sealing device 100) combining a mechanical seal and a magnetic liquid seal according to an embodiment of the present invention includes a housing 1, a rotating shaft 2, and a first seal assembly 3.

The housing 1 defines a chamber 104, and the shaft 2 is rotatably disposed in the chamber 104.

The first seal assembly 3 includes a stationary ring 301, a rotating ring 302, a first pole piece 303, a second pole piece 304, and a first permanent magnet 305.

The rotating shaft 2 penetrates through the static ring 301, the static ring 301 is in sealing fit with the shell 1 or the static ring 301 is connected with the shell 1, and the static ring 301 and the rotating shaft 2 are arranged at intervals in the inner and outer directions. The stationary ring 301 has a first annular seal surface 3011 extending in the inward and outward directions.

The spin ring 302 includes a spin ring body 3021 and a first ring body 3022 connected to the spin ring body 3021. The rotating ring body 3021 is sleeved outside the rotating shaft 2 and connected with the rotating shaft 2, and the first ring body 3022 is in sealing fit with the first annular sealing surface 3011.

The first pole piece 303 is sleeved outside the rotating shaft 2 and connected with the rotating ring 302, and the second pole piece 304 is sleeved outside the first pole piece 303 and connected with the rotating ring 302. Each of the first and

second pole pieces

303, 304 is opposed to the first ring 3022 in the inner-outer direction.

Each of the first and

second pole pieces

303, 304 is located inboard or outboard of the first ring 3022 in the inboard-outboard direction. In other words, each of the first and

second pole pieces

303, 304 is located inboard of the first ring 3022 in the inboard-outboard direction or each of the first and

second pole pieces

303, 304 is located outboard of the first ring 3022 in the inboard-outboard direction.

Each of the first and

second pole pieces

303 and 304 is spaced apart from the first annular sealing face 3011 in the axial direction of the rotating shaft 2 to form a first sealing gap filled with the magnetic liquid 10.

The first permanent magnet 305 is sleeved outside the first pole piece 303, the second pole piece 304 is sleeved outside the first permanent magnet 305, and the first permanent magnet 305 has an N pole and an S pole which are opposite in the inner and outer directions.

According to the sealing device 100 provided by the embodiment of the invention, the stationary ring 301 is in sealing fit with the housing 1, or the stationary ring 301 is connected with the housing 1, and the rotating ring body 3021 of the rotating ring 302 is connected with the rotating shaft 2, so that when the sealing device 100 is installed on equipment and the equipment is in a working state, the stationary ring 301 and the housing 1 are sealed, the rotating ring 302 and the rotating shaft 2 are sealed, and the rotating ring 302 rotates along with the rotating shaft 2 relative to the stationary ring 301, so that the sealing performance of the sealing device 100 on fluid in the equipment can be effectively ensured as long as the sealing performance between the rotating ring 302 and the stationary ring 301 is ensured.

The sealing device 100 according to the embodiment of the present invention not only forms a mechanical seal by the sealing fit of the first ring body 3022 and the first annular sealing surface 3011, but also forms a magnetic-liquid seal by the first permanent magnet 305 by providing magnetic field force to the magnetic liquid 10 at the first pole piece 303 and the magnetic liquid 10 at the second pole piece 304, so that the first pole piece 303, the second pole piece 304, the first permanent magnet 305 and the magnetic liquid 10 disposed in the first sealing gap form a magnetic-liquid seal, thereby forming a combined sealing form of a mechanical seal and a magnetic-liquid seal between the rotating ring 302 and the stationary ring 301.

The mechanical seal has the advantages of being suitable for severe working conditions such as high temperature, low temperature, high pressure, vacuum, various strong corrosive media, solid particle-containing media and the like, and has the defect of small amount of leakage; magnetic liquid seals have the advantage of zero leakage, while having the disadvantage of being difficult to adapt to high pressures and liquid seals. Therefore, the sealing device 100 according to the embodiment of the invention can be applied to various working conditions under the condition of ensuring zero leakage by using a combined sealing mode of mechanical sealing and magnetic liquid sealing.

For example, when the fluid in the device to which the sealing device 100 is applied is a high-pressure liquid, the stationary ring 301 is adjacent to the rotating ring 302 in the axial direction of the rotating shaft 2, and each of the first pole piece 303 and the second pole piece 304 is located outside the first ring body 3022 in the inner and outer directions, so that the fluid in the device in the working state can firstly pass through the mechanical seal formed by the first ring body 3022 and the first annular sealing surface 3011, and a magnetic-liquid seal can be formed by the first pole piece 303, the second pole piece 304, the first permanent magnet 305 and the magnetic liquid 10 arranged in the first sealing gap only when a small amount of leakage occurs when the fluid passes through the mechanical seal. Since only a small amount of fluid leaks after the mechanical sealing, only a small amount of leaked fluid passes through the magnetic liquid seal, on one hand, the small amount of leaked fluid does not have a great influence on the components of the magnetic liquid 10 (does not dilute the magnetic liquid 10 too much), and on the other hand, the small amount of leaked fluid has a low pressure and does not have a great impact on the magnetic liquid 10 at the magnetic liquid seal. Therefore, the sealing performance of the magnetic liquid sealing position can be effectively ensured, and the sealing device 100 can be suitable for high-pressure working conditions and working conditions that the fluid is liquid.

Therefore, the sealing device 100 according to the embodiment of the invention has the advantages of good sealing effect, applicability to various working conditions and the like.

A sealing device 100 implemented according to the present invention is described in detail below with reference to the accompanying drawings.

As shown in fig. 1 to 5, a sealing apparatus 100 according to an embodiment of the present invention includes a housing 1, a rotating shaft 2, and a first seal assembly 3.

For example, the housing 1 includes a housing main body 101, a first end cap 102, and a second end cap 103, the housing main body 101 having a first end 1013 and a second end 1014 opposite in the axial direction of the rotating shaft 2, the first end cap 102 being provided on the first end 1013, the second end cap 103 being provided on the second end 1014. The housing body 101, the first end cap 102 and the second end cap 103 define a chamber 104, and the rotary shaft 2 is rotatably provided in the chamber 104.

The rotating shaft 2 penetrates through the static ring 301, the static ring 301 is in sealing fit with the shell 1, or the static ring 301 is connected with the shell 1. The stationary ring 301 is provided at a distance from the rotary shaft 2 in the inward and outward directions, and the stationary ring 301 has a first annular seal surface 3011 extending in the inward and outward directions.

In order to make the technical solution of the present application easier to understand, the following further describes the technical solution of the present application by taking the case where the axial direction of the rotating shaft 2 coincides with the left-right direction and the inner-outer direction coincides with the radial direction of the rotating shaft 2. The left-right direction is indicated by an arrow C in fig. 1, and the inward-outward direction is indicated by an arrow D in fig. 1.

As shown in fig. 1, the first endcap 102 can be a left endcap and the second endcap 103 can be a right endcap. The first cover 102 (left cover) is provided on the first end 1013 (left end) of the case main body 101, and the second cover 103 (right cover) is provided on the second end 1014 (right end) of the case main body 101.

The rotating shaft 2 penetrates through the stationary ring 301 in the left-right direction, the stationary ring 301 is disposed apart from the rotating shaft 2 in the radial direction of the rotating shaft 2, and the stationary ring 301 has a first annular seal surface 3011 extending in the radial direction of the rotating shaft 2.

Here, inward means a direction adjacent to the central axis of the rotating shaft 2 on a plane perpendicular to the axial direction of the rotating shaft 2, and outward means a direction away from the central axis of the rotating shaft 2 on a plane perpendicular to the axial direction of the rotating shaft 2, for example, an inner peripheral surface of the housing 1 is adjacent to the central axis of the rotating shaft 2 on a plane perpendicular to the axial direction of the rotating shaft 2, and an outer peripheral surface of the housing 1 is away from the central axis of the rotating shaft 2 on a plane perpendicular to the axial direction of the rotating shaft 2.

The spin ring 302 includes a spin ring body 3021 and a first ring body 3022 connected to the spin ring body 3021. The rotary ring main body 3021 is fitted around the outside of the rotary shaft 2 and is connected to the rotary shaft 2. The first ring body 3022 is in sealing engagement with the first annular sealing surface 3011.

For example, as shown in fig. 1, the stationary ring 301 is disposed on the left side of the rotary ring 302, the left end face of the stationary ring 301 constitutes the first annular seal surface 3011, the first ring body 3022 is disposed on the left side of the rotary ring main body 3021, and the left end face of the first ring body 3022 is sealingly engaged with the first annular seal surface 3011.

In some embodiments, the stationary ring 301 is further provided with a second annular seal surface 3012 extending in the inward-outward direction, the housing 1 is provided with a third annular seal surface 1021 extending in the inward-outward direction, and the second annular seal surface 3012 is disposed adjacent to the first annular seal surface 3011 with respect to the third annular seal surface 1021 in the axial direction of the rotating shaft 2.

A first elastic sealing ring 306 is arranged between the second annular sealing surface 3012 and the third annular sealing surface 1021, in other words, the first elastic sealing ring 306 is press-fitted between the second annular sealing surface 3012 and the third annular sealing surface 1021 in the axial direction of the rotary shaft 2. For example, as shown in FIG. 2, the right side of the first elastomeric seal ring 306 engages the second annular seal surface 3012, and the left side of the first elastomeric seal ring 306 engages the third annular seal surface 1021. The stationary ring 301 is in sealing engagement with the housing 1 via a first resilient sealing ring 306.

Therefore, when the device is in operation, when the rotating ring 302 slightly moves relative to the stationary ring 301 in the axial direction of the rotating shaft 2 to cause the first ring body 3022 to leave the first annular sealing surface 3011, the first elastic sealing ring 306 can slightly elastically deform in the axial direction of the rotating shaft 2, so that the stationary ring 301 slightly moves in the axial direction of the rotating shaft 2, and the first ring body 3022 is always in sealing fit with the first annular sealing surface 3011, which is beneficial to improving the sealing performance of the mechanical sealing position of the first sealing assembly 3.

Preferably, the stationary ring 301 is further provided with a fourth annular sealing surface 3013 extending in the axial direction of the rotating shaft 2, the housing 1 is further provided with a fifth annular sealing surface 1022 extending in the axial direction of the rotating shaft 2, and the fourth annular sealing surface 3013 and the fifth annular sealing surface 1022 are arranged at intervals in the inward-outward direction.

A first resilient seal ring 306 is disposed between the fourth annular sealing surface 3013 and the fifth annular sealing surface 1022. In other words, the first resilient sealing ring 306 is press-fit in the inward-outward direction between the fourth annular sealing surface 3013 and the fifth annular sealing surface 1022. For example, as shown in FIG. 2, the outer side of the first elastomeric seal ring 306 abuts the fifth annular sealing surface 1022, and the inner side of the first elastomeric seal ring 306 abuts the fourth annular sealing surface 3013.

From this, equipment during operation, when stationary ring 301 takes place a small amount of movements at the axial of pivot 2 and leads to stationary ring 301 to leave casing 1 for casing 1, less elastic deformation can take place along inside and outside direction in first elastic seal 306 to make stationary ring 301 take place a small amount of movements along inside and outside direction, and then make stationary ring 301 all the time with casing 1 seal fit, be favorable to improving the sealing performance between stationary ring 301 and the casing 1.

The first pole piece 303 is sleeved outside the rotating shaft 2 and connected with the rotating ring 302, and the second pole piece 304 is sleeved outside the first pole piece 303 and connected with the rotating ring 302. The connection of the first pole piece 303 to the spin ring 302 can be either the connection of the first pole piece 303 to the spin ring body 3021 of the spin ring 302 or the connection of the first pole piece 303 to the first ring body 3022 of the spin ring 303. The second pole piece 304 is coupled to the spin ring 302 either by coupling the second pole piece 304 to the spin ring body 3021 of the spin ring 302 or by coupling the second pole piece 304 to the first ring body 3022 of the spin ring 303.

Each of the first and

second pole pieces

303, 304 is opposed to the first ring 3022 in the inner-outer direction. Each of the first and

second pole pieces

303, 304 is located inboard or outboard of the first ring 3022 in the inboard-outboard direction.

For example, as shown in fig. 1-4, each of the first and

second pole pieces

303, 304 is located outboard of the first ring 3022 in the inboard and outboard directions, with the first pole piece 303 nested outboard of the first ring 3022 and the second pole piece 304 nested outboard of the first pole piece 303.

Each of the first and

second pole pieces

For example, as shown in fig. 1 to 5, the first pole piece 303 is provided with a first pole tooth 3031 on the left side, the first pole tooth 3031 is spaced from the first annular sealing surface 3011 in the axial direction of the rotating shaft 2, and the magnetic liquid 10 is filled between the first pole tooth 3031 and the first annular sealing surface 3011. The second pole piece 304 is provided with a second pole tooth 3041 on the left side, the second pole tooth 3041 is spaced from the first annular sealing surface 3011 in the axial direction of the rotating shaft 2, and the magnetic liquid 10 is filled between the second pole tooth 3041 and the first annular sealing surface 3011.

In some embodiments, the spin ring 302 further includes a second ring body 3023, the second ring body 3023 being disposed in a spaced apart relationship from the first ring body 3022 in the inboard and outboard directions, the second ring body 3023 being coupled to the spin ring body 3021, the second ring body 3023 being in sealing engagement with the first annular sealing surface 3011. The first pole piece 303, the second pole piece 304, and the first permanent magnet 305 are located between the first ring body 3022 and the second ring body 3023 in the inward and outward direction.

For example, as shown in fig. 1 to 4, the second ring body 3023 is located outside the first ring body 3022, the second ring body 3023 is provided on the left side of the rotary ring body 3021, and the left end surface of the second ring body 3023 is sealingly engaged with the first annular seal surface 3011. The first pole piece 303, the second pole piece 304, and the first permanent magnet 305 are located between the first ring body 3022 and the second ring body 3023 in the inward and outward direction.

When the fluid pressure in the device to which the sealing device 100 is applied is negative pressure, that is, the fluid pressure in the device is lower than the external environment pressure, the stationary ring 301 is adjacent to the device relative to the rotating ring 302 in the axial direction of the rotating shaft 2, so that the fluid in the device in the working state and the substance (for example, air) in the external environment can firstly pass through the mechanical seal formed by the second ring body 3023 and the first annular sealing surface 3011, and a magnetic-liquid seal can be formed through the first pole piece 303, the second pole piece 304, the first permanent magnet 305 and the magnetic liquid 10 arranged in the first sealing gap only in the case of a small amount of leakage when the fluid passes through the mechanical seal. Since even a small amount of fluid leaks from the mechanical seal, only a small amount of leaked fluid passes through the magnetic liquid seal, on one hand, the small amount of leaked fluid does not have a great influence on the components of the magnetic liquid 10 (does not dilute the magnetic liquid 10 too much), and on the other hand, the small amount of leaked fluid has a low pressure and does not have a great impact on the magnetic liquid 10 at the magnetic liquid seal. Therefore, the sealing performance of the magnetic liquid sealing position can be effectively ensured, and the sealing device 100 can be suitable for the negative pressure working condition. Furthermore, the sealing device 100 according to the embodiment of the invention can be applied to more working conditions.

Further, since the stationary ring 301, the second ring body 3023, and the rotating ring body 3021 enclose a closed space, the magnetic liquid 10 filled in the first seal gap is located in the closed space. Therefore, when the fluid in the device is a high-temperature fluid, the magnetic liquid 10 in the first sealing gap can be reduced or avoided from volatilizing out of the closed space due to high temperature, and therefore, the sealing performance of the magnetic liquid sealing position is ensured, and the sealing device 100 can be suitable for high-temperature working conditions. Furthermore, the sealing device 100 according to the embodiment of the invention can be applied to more working conditions.

Preferably, the second ring body 3023 is located outside the first ring body 3022 in the inside-outside direction, and the first ring body 3022 is disposed spaced apart from the rotation shaft 2 in the inside-outside direction.

Therefore, the size of the first ring body 3022 in the inner and outer directions is not too large, which can effectively reduce the contact area between the first ring body 3022 and the stationary ring 301, so as to reduce the heat generated by the friction between the first ring body 3022 and the stationary ring 301 when the device works, which is beneficial to improving the sealing performance of the sealing device 100.

Preferably, the second ring body 3023 and the first ring body 3022 are each formed by two groove side walls of a ring groove provided on the rotating ring 302.

In some embodiments, the first seal assembly 3 is provided in plurality, and the plurality of first seal assemblies 3 are provided at intervals in the axial direction of the rotating shaft 2.

Thus, the sealing performance of the sealing device 100 can be effectively improved by using the plurality of first seal assemblies 3.

In other embodiments, the sealing device 100 further comprises a second seal assembly 4, and the first seal assembly 3 and the second seal assembly 4 are spaced apart along the axial direction of the rotating shaft 2.

The second seal assembly 4 comprises a third pole piece 401, a fourth pole piece 402 and a second permanent magnet 403. Each of the third pole piece 401 and the fourth pole piece 402 is fitted around the outer side of the rotating shaft 2, and each of the third pole piece 401 and the fourth pole piece 402 is connected to the housing 1.

An inner peripheral surface of each of the third pole piece 401 and the fourth pole piece 402 is spaced from a peripheral surface of the rotating shaft 2 in the inward and outward direction to form a second seal gap, which is filled with a magnetic liquid.

For example, the inner peripheral surface of the third pole piece 401 is provided with third pole teeth 4011, the third pole teeth 4011 are spaced apart from the peripheral surface of the rotating shaft 2 in the inward and outward direction, and the magnetic liquid 10 is filled between the third pole teeth 4011 and the peripheral surface of the rotating shaft 2. The fourth pole piece 402 has fourth pole teeth 4021 on an inner peripheral surface thereof, the fourth pole teeth 4021 are spaced from a peripheral surface of the rotating shaft 2 in the inward and outward direction, and a magnetic liquid 10 is filled between the fourth pole teeth 4021 and the peripheral surface of the rotating shaft 2.

The second permanent magnet 403 is fitted around the outer side of the rotating shaft 2, the second permanent magnet 403 is located between the third pole piece 401 and the fourth pole piece 402 in the axial direction of the rotating shaft 2, and the second permanent magnet 403 has N and S poles opposite to each other in the axial direction of the rotating shaft 2.

Therefore, the second sealing assembly 4 and the rotating shaft 2 form magnetic liquid seal, and the second sealing assembly 4 is arranged on the basis of the first sealing assembly 3, so that the sealing performance of the sealing device 100 can be effectively improved.

Preferably, the first seal assembly 3 is provided in plurality, the plurality of first seal assemblies 3 are arranged at intervals in the axial direction of the rotating shaft 2, and the second seal assembly 4 is located between two adjacent first seal assemblies 3 in the axial direction of the rotating shaft 2.

For example, as shown in fig. 1, the first seal assembly 3 is provided in two, and the second seal assembly 4 is located between the two first seal assemblies 3 in the axial direction of the rotating shaft 2.

Therefore, the sealing failure of the second sealing assembly 4 caused by the fact that high-temperature fluid, high-pressure fluid or liquid passes through the second sealing assembly 4 and then passes through the first sealing assembly 3 is avoided, and the sealing performance of the sealing device 4 is further improved.

It should be noted that, when only one first seal assembly 3 is provided, the second seal assembly 4 should be provided away from the high-pressure side with respect to the first seal assembly 3 in the axial direction of the rotating shaft 2. For example, when the fluid in the apparatus is a high-pressure fluid, the second seal assembly 4 is disposed away from the apparatus in the axial direction of the rotating shaft 2 with respect to the first seal assembly 3. Thereby, the magnetic liquid at the second sealing assembly 4 can be reduced or avoided from being broken by the high-pressure fluid, which is beneficial to further improve the sealing performance of the sealing device 100.

Preferably, an annular protrusion 1011 is provided on an inner peripheral surface of the housing 1, the annular protrusion 1011 is located between two adjacent first seal assemblies 3 in the axial direction of the rotating shaft 2, the second seal assembly 4 is opposed to the annular protrusion 1011 in the inward and outward direction, an outer peripheral surface of each of the third pole shoe 401 and the fourth pole shoe 402 is connected to a peripheral surface of the annular protrusion 1011, and the stationary ring 301 of at least one of the two adjacent first seal assemblies 3 is connected to the annular protrusion 1011.

For example, as shown in fig. 1, the first seal assembly 3 is provided in two, and the second seal assembly 4 is located between the two first seal assemblies 3 in the axial direction of the rotating shaft 2. The stationary ring 301 of the first seal assembly 3, which is located on the right side of the second seal assembly 4, is connected to an annular projection 1011.

The stationary ring 301 of at least one of the two adjacent first seal assemblies 3 is connected to the annular protrusion 1011, so that the first seal assembly 3 and the second seal assembly 4 are closer to each other in the axial direction of the rotating shaft 2, the overall structure of the seal device 100 is more compact, and the miniaturization design of the seal device 100 is facilitated.

In some embodiments, the sealing device 100 further includes a first seal ring 5, the inner circumferential surface of the rotating ring body 3021 is provided with a first seal ring groove 30211, the first seal ring 5 is fixedly installed in the first seal ring groove 30211, and the inner circumferential surface of the first seal ring 5 is attached to the circumferential surface of the rotating shaft 2.

This improves the sealing performance between the rotary ring main body 3021 and the rotary shaft 2 by the first seal ring 5, which is advantageous in further improving the sealing performance of the sealing device 100.

In some embodiments, the first seal assembly 3 further comprises a second seal ring 3032, the first pole piece 303 is provided with a second seal ring groove, the second seal ring 3032 is fixedly mounted in the second seal ring groove, and an end surface of the second seal ring 3032 adjacent to the rotating ring main body 301 is abutted against an end surface of the rotating ring main body 301 adjacent to the second seal ring 3032.

For example, as shown in fig. 1, the second seal ring groove is provided on the right end surface of the first pole piece 303, and the right end surface of the second seal ring 3032 is attached to the left end surface of the rotating ring main body 301.

Accordingly, the second seal 3032 can improve the sealing performance between the first pole piece 303 and the rotating ring main body 301, which is advantageous in further improving the sealing performance of the sealing device 100.

In some embodiments, the first seal assembly 3 further includes a third seal ring 3042, the second pole piece 304 is provided with a third seal ring groove, the third seal ring 3042 is fixedly mounted in the third seal ring groove, and an end surface of the third seal ring 3042 adjacent to the rotating ring body 301 is abutted against an end surface of the rotating ring body 301 adjacent to the third seal ring 3042.

For example, as shown in fig. 1, a third seal ring groove is provided on the right end surface of the second pole piece 304, and the right end surface of the third seal ring 3042 is fitted to the left end surface of the rotating ring main body 301.

Accordingly, the third seal ring 3042 can improve the sealing performance between the second pole piece 304 and the rotating ring main body 301, which is advantageous in further improving the sealing performance of the sealing device 100.

In some embodiments, the second sealing assembly 4 further includes a fourth sealing ring 4012, a fourth sealing ring groove is formed on the outer peripheral surface of the third pole shoe 401, the fourth sealing ring 4012 is fixedly installed in the fourth sealing ring groove, and the outer peripheral surface of the fourth sealing ring 4012 is attached to the inner peripheral surface of the housing 1.

Accordingly, the fourth seal 4012 can improve the sealing performance between the third pole piece 401 and the housing 1, which is advantageous for further improving the sealing performance of the sealing device 100.

In some embodiments, the second seal assembly 4 further comprises a fifth seal ring 4022, a fifth seal ring groove is formed on the outer peripheral surface of the fourth pole shoe 402, the fifth seal ring 4022 is fixedly installed in the fifth seal ring groove, and the outer peripheral surface of the fifth seal ring 4022 is attached to the inner peripheral surface of the housing 1.

Accordingly, the fifth seal 4022 improves the sealing performance between the fourth pole shoe 402 and the housing 1, which is advantageous for further improving the sealing performance of the sealing device 100.

In some embodiments, the spin ring body 3021 of the spin ring 302 has an interference fit with the spindle 2, which enables the coupling of the spin ring body 3021 to the spindle 2. The sealing device 100 further comprises a clamp spring 6, a clamp spring groove is formed in the rotating shaft 2, the clamp spring 6 is installed in the clamp spring groove, and the clamp spring 6 is used for axially positioning the rotating ring main body 3021.

Preferably, the first and second seal gaps are 0.05-0.3mm, for example, each of the first and second seal gaps is 0.1 mm.

Preferably, each of the first and second end caps 102 and 103 is connected to the housing main body 101 by bolts, the number and positions of the threaded holes on each of the first and

second end portions

1012 and 1013 of the housing main body 101 are the same, and 2N (N is an integer greater than or equal to 2) threaded holes on each of the first and

second end portions

1012 and 1013 are uniformly distributed in the circumferential direction.

Preferably, threaded holes are reserved at the flange of the first end cover 102, and 2N (N is an integer greater than or equal to 2) threaded holes are uniformly distributed along the circumferential direction of the housing main body 101 and are used for connecting with equipment.

Preferably, the threaded holes in the first end cap 102 connected to the housing body 101 and the reserved threaded holes in the first end cap 102 connected to the device are spaced apart in the inside-outside direction.

The housing body 101, the first end cap 102, the second end cap 103, and the rotating ring 302 are made of a non-conductive magnet material, such as stainless steel or aluminum. The first pole shoe 303, the second pole shoe 304, the third pole shoe 401 and the fourth pole shoe 402 are made of materials with good magnetic conductivity, such as electrician pure iron, and the stationary ring 301 is made of metal materials with good magnetic conductivity and high hardness, such as alloy steel. The magnetic liquid 10 can be a magnetic liquid with high-quality kerosene or silicate ester or diester as a base carrier liquid, and has good high-temperature resistance.

The assembling process of the sealing device 100 shown in fig. 1 to 5 will be described by taking as an example that the axial direction of the rotating shaft 2 coincides with the left-right direction and the inner-outer direction coincides with the radial direction of the rotating shaft 2:

for ease of understanding, the assembly process of the sealing device 100 shown in fig. 1 to 5 will be described by taking the first sealing assembly 3 located on the left side of the second sealing assembly 2 as the left first sealing assembly and the first sealing assembly 3 located on the right side of the second sealing assembly 2 as the right first sealing assembly.

First, the installation of the left first seal assembly is performed: the circlip 6 corresponding to the left first seal assembly is installed in the corresponding circlip groove, the first seal ring 5 of the left first seal assembly is installed in the first seal ring groove 30211 of the rotary ring 302 of the left first seal assembly, and the rotary ring 302 is installed on the rotating shaft 2 in an interference fit manner so as to rotate synchronously with the rotating shaft 2. A magnetic liquid sealing device is installed between the first ring body 3022 and the second ring body 3023 of the rotating ring 302 of the left first sealing assembly by sequentially placing the first pole piece 303, the first permanent magnet 305 and the second pole piece 304 into the grooves formed by the first ring body 3022 and the second ring body 3023, enabling the inner circumferential surface of the first pole piece 303 to be tightly matched with the outer circumferential surface of the first ring body 3022 and the outer circumferential surface of the second pole piece 304 to be tightly matched with the inner circumferential surface of the second ring body 3023, and filling the magnetic liquid 10 into the first pole tooth 3031 and the second pole tooth 3041. The stationary ring 301 of the left first seal assembly is placed to the left of the rotating ring 302 of the left first seal assembly. Thereafter, a first elastomeric seal ring 306 is disposed between the second annular sealing surface 3012 and the fourth annular sealing surface 3013 of the left first seal assembly stationary ring 301. The first end cover 102 is tightly coupled to the first end portion 1012 of the housing main body 101 using bolts.

Next, the second seal assembly 2 is mounted: the third pole piece 401, the second permanent magnet 403 and the fourth pole piece 402 are sequentially placed into the annular protrusion 1011 from the right side of the rotating shaft 2, the outer peripheral surfaces of the third pole piece 401, the second permanent magnet 403 and the fourth pole piece 402 are tightly matched with the peripheral surface of the annular protrusion 1011, and magnetic liquid is filled in the second sealing gap.

Finally, the installation of the right first seal assembly is carried out: the stationary ring 301 and the rotating ring 302 of the right first seal assembly are sequentially inserted into the housing 1, and the stationary ring 301 and the rotating ring 302 are specifically mounted in the manner of referring to the stationary ring 301 and the rotating ring 302 of the left first seal assembly, the snap spring 6 corresponding to the right first seal assembly is mounted in the corresponding snap spring groove, and the second end cover 103 is connected to the second end 1013 of the housing main body 101 by bolts.

The sealing device 100 according to the embodiment of the present invention has the following advantageous effects:

(1) the mechanical seal and the magnetic liquid seal are combined, so that the sealing device is effectively applied to various working conditions under the condition of ensuring zero leakage, such as high pressure, high temperature, liquid fluid and the like.

(2) Through the mode that the fluting set up the magnetic fluid seal on rotatory ring 302, not only reduced the area of contact of stationary ring 301 and rotatory ring 302, solved mechanical seal and issued the problem that the heat is big under operating condition, still make sealed between stationary ring 301 and the rotatory ring 302 complete, increased sealed reliability.

(3) Most or even all of the dynamic sealing surfaces can be arranged on other parts except the rotating shaft 2, so that the sealing device 100 is insensitive to vibration and deflection of the rotating shaft 2 relative to the chamber 104, abrasion of the rotating shaft 2 can be effectively reduced or avoided, and the service life of the sealing device 100 is prolonged.

In the description of the present invention, it is to be understood that the terms "central," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," "circumferential," and the like are used in the orientations and positional relationships indicated in the drawings for convenience in describing the invention and to simplify the description, and are not intended to indicate or imply that the referenced devices or elements must have a particular orientation, be constructed and operated in a particular orientation, and are therefore not to be considered limiting of the invention.

Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature. In the description of the present invention, "a plurality" means at least two, e.g., two, three, etc., unless specifically limited otherwise.

In the present invention, unless otherwise expressly stated or limited, the terms "mounted," "connected," "secured," and the like are to be construed broadly and can, for example, be fixedly connected, detachably connected, or integrally formed; may be mechanically coupled, may be electrically coupled or may be in communication with each other; they may be directly connected or indirectly connected through intervening media, or they may be connected internally or in any other suitable relationship, unless expressly stated otherwise. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations.

In the present invention, unless otherwise expressly stated or limited, the first feature "on" or "under" the second feature may be directly contacting the first and second features or indirectly contacting the first and second features through an intermediate. Also, a first feature "on," "over," and "above" a second feature may be directly or diagonally above the second feature, or may simply indicate that the first feature is at a higher level than the second feature. A first feature being "under," "below," and "beneath" a second feature may be directly under or obliquely under the first feature, or may simply mean that the first feature is at a lesser elevation than the second feature.

In the present disclosure, the terms "one embodiment," "some embodiments," "an example," "a specific example," or "some examples" and the like mean that a specific feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the present disclosure. In this specification, the schematic representations of the terms used above are not necessarily intended to refer 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. Furthermore, various embodiments or examples and features of different embodiments or examples described in this specification can be combined and combined by one skilled in the art without contradiction.

Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention, and that variations, modifications, substitutions and alterations can be made to the above embodiments by those of ordinary skill in the art within the scope of the present invention.

Claims

1. A mechanical seal and magnetic fluid seal combined seal, comprising:

a housing defining a chamber;

the rotating shaft is rotatably arranged in the cavity; and

a first seal assembly, the first seal assembly comprising:

2. A combined mechanical and magnetic-fluid-seal apparatus as claimed in claim 1, wherein said rotating ring further includes a second ring body disposed in spaced relation to said first ring body in an inboard-outboard direction, said second ring body being connected to said rotating ring body, said second ring body being in sealing engagement with said first annular seal surface, said first pole piece, said second pole piece and said first permanent magnets being located between said first ring body and said second ring body in an inboard-outboard direction.

3. A combined mechanical and magnetic fluid seal according to claim 2 wherein said second ring is located outwardly of said first ring in an inboard and outboard direction, said first ring being spaced from said shaft in the inboard and outboard direction.

4. The combined mechanical seal and magnetic fluid seal apparatus of any one of claims 1 to 3, further comprising a first seal ring, wherein a first seal ring groove is formed on an inner peripheral surface of said rotating ring body, said first seal ring is fixedly installed in said first seal ring groove, and an inner peripheral surface of said first seal ring is fitted to a peripheral surface of said rotating shaft.

5. A combined mechanical and magnetic fluid seal arrangement according to any one of claims 1 to 3, wherein said stationary ring is further provided with a second annular sealing surface extending in the inward-outward direction, said housing is provided with a third annular sealing surface extending in the inward-outward direction, said second annular sealing surface is disposed adjacent to said first annular sealing surface with respect to said third annular sealing surface in the axial direction of said shaft, a first elastic sealing ring is disposed between said second annular sealing surface and said third annular sealing surface, and said stationary ring is sealingly engaged with said housing by said first elastic sealing ring.

6. A combined mechanical and magnetic fluid seal arrangement according to claim 5, wherein said stationary ring is further provided with a fourth annular sealing surface extending in the axial direction of said shaft, said housing is further provided with a fifth annular sealing surface extending in the axial direction of said shaft, said fourth and fifth annular sealing surfaces are arranged at a distance in the inward-outward direction, and said first resilient seal ring is arranged between said fourth and fifth annular sealing surfaces.

7. The mechanical seal and magnetic fluid seal combined sealing device of any one of claims 1-3, further comprising a second seal assembly, said first and second seal assemblies being disposed spaced apart along an axial direction of said shaft, said second seal assembly comprising:

8. The combined mechanical seal and magnetic fluid seal apparatus of claim 7, wherein said first seal assembly is provided in plurality, and a plurality of said first seal assemblies are provided at intervals along an axial direction of said rotating shaft, and said second seal assembly is located between two adjacent said first seal assemblies in the axial direction of said rotating shaft.

9. The combined mechanical and magnetic fluid seal apparatus of claim 8, wherein an annular protrusion is provided on an inner circumferential surface of the housing, the annular protrusion is located between two adjacent first seal members in an axial direction of the rotating shaft, the second seal member is opposite to the annular protrusion in an inner and outer direction, an outer circumferential surface of each of the third pole piece and the fourth pole piece is connected to a circumferential surface of the annular protrusion, and a stationary ring of at least one of the two adjacent first seal members is connected to the annular protrusion.

10. A combined mechanical and magnetic-fluid-tight seal according to any of claims 1-3, wherein said first seal assembly is provided in plurality, and a plurality of said first seal assemblies are provided spaced apart in the axial direction of said shaft.