CN112178201B

CN112178201B - Magnetic liquid sealing device

Info

Publication number: CN112178201B
Application number: CN202011057012.XA
Authority: CN
Inventors: 李德才; 刘霄; 李英松
Original assignee: Tsinghua University
Current assignee: Tsinghua University
Priority date: 2020-09-29
Filing date: 2020-09-29
Publication date: 2021-08-17
Anticipated expiration: 2040-09-29
Also published as: CN112178201A

Abstract

The invention provides a magnetic liquid sealing device which comprises a shaft shell, a rotating shaft, a first heat retainer, a pole shoe, at least one permanent magnet and a sealing cavity. The shaft housing defines a shaft chamber. The rotating shaft is rotatably arranged in the shaft chamber and extends into the shaft chamber from one end of the shaft shell and extends out from the other end of the shaft shell. First heat retainer is established on the outer peripheral face of axostylus axostyle shell, and first heat retainer has first heat preservation chamber or prescribes a limit to first heat preservation chamber between first heat retainer and the outer peripheral face of axostylus axostyle shell, and it has first phase change material to fill in the first heat preservation chamber. The pole shoe is sleeved on the rotating shaft, the peripheral surface of the pole shoe is connected with the peripheral wall surface of the shaft chamber, the permanent magnet is sleeved on the rotating shaft, the permanent magnet is matched with the pole shoe, and each of the pole shoe and the permanent magnet is positioned in the shaft chamber; the shaft housing is connected with the seal cavity. The magnetic liquid sealing device can avoid sealing failure caused by environmental temperature difference, and has the advantages of stable work and suitability for space working conditions.

Description

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.

Background

Magnetic liquid sealing devices are widely used in more and more industries as a sealing method capable of realizing 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, when the magnetic liquid sealing device is actually applied in space, due to the actual working condition of large temperature difference in space, the sunny side of the planet generally exceeds 100 ℃, and the shady side of the planet is lower than minus 100 ℃, so that the normal work of the magnetic liquid sealing device which is circulated around the planet is seriously influenced by the huge temperature difference. For example, when the magnetic liquid seal device bypasses to the sun-facing surface of the planet, the magnetic liquid seal device is prone to seal failure due to evaporation of the magnetic liquid because of being in a high-temperature environment. When the magnetic liquid sealing device bypasses to the back shadow surface of the planet, the magnetic liquid sealing device can cause the sealing failure due to the overlarge starting torque caused by the increase of the viscosity of the magnetic liquid in a low-temperature environment. Therefore, the existing magnetic liquid sealing device can not be used for zero leakage and is well suitable for space working conditions.

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 magnetic liquid sealing device, which solves the problem that the sealing effect of the magnetic liquid sealing device is influenced by a huge temperature difference.

According to an embodiment of the present invention, a magnetic liquid sealing device includes: a shaft housing defining a shaft chamber; the rotating shaft is rotatably arranged in the shaft chamber and extends into the shaft chamber from one end of the shaft shell and extends out from the other end of the shaft shell; the first heat retainer is arranged on the outer peripheral surface of the shaft shell, the first heat retainer is provided with a first heat retaining cavity or a first heat retaining cavity is defined between the first heat retainer and the outer peripheral surface of the shaft shell, and a first phase-change material is filled in the first heat retaining cavity; the pole shoe is sleeved on the rotating shaft, the outer peripheral surface of the pole shoe is connected with the peripheral wall surface of the shaft chamber, a plurality of pole teeth are arranged on the inner peripheral surface of the pole shoe along the axial direction of the rotating shaft, tooth grooves are formed between every two adjacent pole teeth, magnetic liquid for sealing is arranged between the tooth top surface of each pole tooth and the peripheral surface of the rotating shaft, and the magnetic liquid is adsorbed on the tooth top surface; the permanent magnet is sleeved on the rotating shaft, the permanent magnet is matched with the pole shoe, and each of the pole shoe and the permanent magnet is positioned in the shaft chamber; and the shaft shell is connected with the seal cavity.

The magnetic liquid sealing device according to the present invention is provided with the first heat retainer on the outer peripheral surface of the shaft housing so as to form the first heat-retaining chamber on the outer peripheral surface of the shaft housing, and the first heat-retaining chamber is filled with the first phase-change material. Because the first phase-change material can store heat and release heat, the huge environment temperature difference of the magnetic liquid sealing device above the sun-facing surface and above the back-shade surface of the planet can be dealt with, the sealing failure of the magnetic liquid sealing device caused by the evaporation or viscosity increase of the magnetic liquid due to the environment temperature difference is avoided, and the working stability of the magnetic liquid sealing device is ensured.

Therefore, the magnetic liquid sealing device provided by the invention has the advantages of stable work and particular suitability for space working conditions.

In addition, the magnetic liquid sealing device according to the present invention has the following additional technical features:

in some embodiments, a fin is formed on an inner wall surface of the first heat-preservation cavity, the first phase-change material is in contact with the fin, a first injection hole is formed in the first heat-preservation device, and the first injection hole is communicated with the outside and the first heat-preservation cavity.

In some embodiments, the magnetic liquid seal apparatus further comprises: an end cap mounted on the one end of the axle housing; the second heat retainer is arranged on the outer surface of the end cover, the second heat retainer is provided with a second heat retaining cavity or the second heat retainer and the outer surface of the end cover define a second heat retaining cavity therebetween, and second phase change materials are filled in the second heat retaining cavity.

In some embodiments, a fin is formed on an inner wall surface of the second heat preservation cavity, the second phase change material is in contact with the fin, a second injection hole is formed in the second heat retainer, and the second injection hole is communicated with the outside and the second heat preservation cavity.

In some embodiments, the axle housing includes a first end cap; a housing having a first positioning portion including a positioning table extending in a radial direction of the housing and a first portion provided on a first end surface of the positioning table, the positioning table of the housing being provided on a first end cover opposed to the first portion of the housing in a radial inward-outward direction of the housing, the first end cover being provided spaced apart from the first portion of the housing in the radial inward-outward direction of the housing so that the housing is movable in the radial inward-outward direction relative to the first end cover, wherein at least one of the positioning table and the first end cover is provided with a mounting groove; and an elastic member disposed within the mounting slot, the elastic member being in a compressed state with a portion of the elastic member extending out of the mounting slot, the portion of the elastic member engaging at least one of the positioning table and the first end cap; optionally, the first end cap is spaced from the first portion of the housing by a distance of 0.101mm to 1.999mm or 2.001mm to 20mm in a radially inward and outward direction of the housing.

In some embodiments, the first portion is a positioning sleeve extending along the axial direction of the housing, and the first end cap is sleeved outside the first portion of the housing or the first portion of the housing is sleeved outside the first end cap; or the first part is a positioning block or a positioning sleeve extending along the axial direction of the shell, a positioning groove along the circumferential direction of the shell is arranged on the end face, opposite to the positioning table, of the first end cover, the first part extends into the positioning groove, and a gap is formed between the first part and the side face of the positioning groove.

In some embodiments, the end face of the first end cover opposite to the shell is provided with the mounting groove, and the part of the elastic element is matched with the shell; optionally, a plurality of mounting grooves are uniformly distributed along the circumferential direction of the housing, the number of the elastic pieces is multiple, the elastic pieces are correspondingly arranged in the mounting grooves one by one, and the shapes of the elastic pieces are matched with the inner surfaces of the mounting grooves; or, the mounting groove is an annular groove, the circumferential direction of the mounting groove is consistent with the circumferential direction of the shell, and the elastic piece is annular.

In some embodiments, the first end face of the first end cover is provided with a second end cover, the second end cover is provided with a second positioning part and a clamping part, the second positioning part is positioned at the inner side of the clamping part, the second end cover is installed on the shell through bolts or screws, so that the second end cover and the shell are matched to clamp the first end cover on the shell, and the diameter of the inner ring of the first positioning part is smaller than that of the inner ring of the shell, so that the second positioning part positions a device in the shell; optionally, a first sealing ring is arranged between the positioning table and the first end cover; optionally, a second sealing ring is arranged between the first end cover and the second end cover.

In some embodiments, the pole pieces include a first pole piece and a second pole piece, the permanent magnets include a first permanent magnet, the first permanent magnet is located between the first pole piece and the second pole piece in an axial direction of the rotating shaft, and each of the first pole piece, the second pole piece, and the first permanent magnet is connected to a peripheral wall surface of the shaft chamber; the magnetic liquid sealing device further includes: the first pole shoe and the second pole shoe are positioned between the first magnetic isolation sleeve and the second magnetic isolation sleeve along the axial direction of the rotating shaft, the first magnetic isolation sleeve is abutted against the first pole shoe, and the second magnetic isolation sleeve is abutted against the second pole shoe; the bearing comprises a first bearing and a second bearing, each of the first bearing and the second bearing is sleeved on the rotating shaft, and the first bearing and the second bearing are arranged at intervals in the axial direction of the rotating shaft.

In some embodiments, each of the first pole piece, the second pole piece, the permanent magnet, the first magnetism isolating sleeve, and the second magnetism isolating sleeve is located between the first bearing and the second bearing in an axial direction of the rotating shaft, the other end of the shaft housing is formed with a protrusion, the first bearing abuts against the protrusion on one side in the axial direction of the rotating shaft, the first bearing abuts against the first magnetism isolating sleeve on the other side in the axial direction of the rotating shaft, and the second bearing abuts against the second magnetism isolating sleeve.

Additional aspects and advantages of the invention will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the invention.

Drawings

Fig. 1 is a schematic structural view of a magnetic liquid sealing apparatus according to an embodiment of the present invention.

FIG. 2 is a schematic structural view of a shaft housing according to one embodiment of the invention.

Fig. 3 is a partially enlarged view of a in fig. 2.

Fig. 4 is a schematic structural view of a shaft housing according to another embodiment of the present invention.

Reference numerals:

a magnetic liquid sealing device 100; a shaft housing 1; a shaft chamber 11; a flange 12; a first end cap 13; a housing 14; the first positioning portion 141; a positioning table 1411; a first portion 1412; an elastic member 15; a mounting groove 16; a first seal ring 17; a second end cap 18; a second positioning portion 181; a clamping portion 182; a second seal ring 19; a rotating shaft 2; a first bearing 31; a second bearing 32; a pole shoe 4; a first pole piece 41; a second pole piece 42; a magnetic liquid 43; a clamp spring 5; a permanent magnet 6; a sealed cavity 7; a sealed cavity 71; a fifth seal ring 72; a first protrusion 8; an end cap 9; a first magnetic shield 101; a second magnetic shield 102; a third seal ring 103; a fourth seal ring 104; a first warmer 200; a first phase change material 210; a first fin 220; the first injection hole 230; a second warmer 300; a second phase change material 310; a second fin 320; and a second injection hole 330.

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.

A magnetic liquid sealing device according to an embodiment of the present invention is described below with reference to fig. 1 to 4.

As shown in fig. 1 to 4, a magnetic fluid sealing apparatus 100 according to an embodiment of the present invention includes a shaft housing 1, a rotating shaft 2, a first heat retainer 200, a pole piece 4, at least one permanent magnet 6, and a seal chamber 7.

The axle housing 1 defines an axle chamber 11. The rotating shaft 2 is rotatably arranged in the shaft chamber 11, and the rotating shaft 2 extends into one end of the shaft chamber 11 and extends out of the other end of the shaft chamber 11.

The first heat retainer 200 is disposed on the outer circumferential surface of the axle housing 1, and the first heat retainer 200 has a first heat retaining cavity or a first heat retaining cavity is defined between the first heat retainer 200 and the outer circumferential surface of the axle housing 1. The first insulating cavity is filled with a first phase change material 210. That is, the first warmer 200 itself may have a first warming chamber for filling the first phase change material 210, and may also define the first warming chamber by cooperating with the outer circumferential surface of the shaft housing 1. The first phase change material 210 is capable of storing and releasing heat.

The pole shoe 4 is sleeved on the rotating shaft 2. The outer circumference of the pole shoe 4 is connected with the circumferential wall of the shaft chamber 11, i.e. the pole shoe 4 is arranged in the shaft housing 1. The inner circumferential surface of the pole shoe 4 is provided with a plurality of pole teeth along the axial direction of the rotating shaft 2, namely the inner circumferential surface of the pole shoe 4 is provided with a plurality of pole teeth which are arranged along the axial direction of the rotating shaft 2, and tooth grooves are formed between adjacent pole teeth. A magnetic liquid 43 for sealing is provided between the tooth crest of each tooth and the circumferential surface of the rotating shaft 2, and the magnetic liquid 43 is adsorbed on the tooth crest of the tooth. In other words, the magnetic liquid 43 contacts both the circumferential surface of the rotating shaft 2 and the tooth tip surface of the pole tooth, so that the magnetic liquid sealing device 100 has a good sealing effect.

The permanent magnet 6 is sleeved on the rotating shaft 2. The permanent magnet 6 cooperates with the pole piece 4 to provide a magnetic force to the pole piece 4 to cause the pole piece 4 to attract the magnetic liquid 43. For example, the permanent magnet 6 abuts against one end surface of the pole shoe 4 in the axial direction of the rotating shaft 2. Each of the pole piece 4 and the permanent magnet 6 is located within the shaft chamber 11. The shaft housing 1 is connected with the seal cavity 7.

When the magnetic liquid sealing device 100 goes around to the sun of the planet, the magnetic liquid sealing device 100 is in a high temperature environment, because the first heat retainer 200 is disposed on the outer circumferential surface of the shaft housing 1 and filled with the first phase change material 210. The first phase change material 210 absorbs heat and increases in temperature. When the temperature of the first phase change material 210 is higher than its phase change temperature, the first phase change material 210 changes phase to absorb heat. When the magnetic liquid sealing device 100 bypasses to the back shadow surface of the planet, the magnetic liquid sealing device 100 is in a low-temperature environment, the first phase change material 210 releases heat and the temperature is continuously reduced, and when the temperature of the first phase change material 210 is lowered to the phase change temperature thereof, the first phase change material 210 generates phase change heat.

Due to the phase change process and the heat absorption and release process of the first phase change material 210, the temperature difference of the magnetic liquid sealing device 100 at the sunny side and the shady side of the planet is reduced. Therefore, the first heat retainer 200 can reduce the influence of temperature on the magnetic liquid 43 in the magnetic liquid sealing device 100, so that the sealing device cannot be sealed and failed due to overhigh or overlow temperature.

In some embodiments, first phase change material 210 is a solid-liquid phase change material. The first phase change material 210 will transform from a solid to a liquid (liquefy) state when it stores heat and reaches a phase change temperature, and the first phase change material 210 will transform from a liquid to a solid (solidify) state when it releases heat. That is, the liquefaction process of the first phase change material 210 is a heat accumulation process, and the solidification process of the first phase change material 210 is an heat release process.

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 taking the axial direction of the rotating shaft 2 as the left-right direction as an example. The one end of the shaft housing 1 is the right end thereof, and the other end of the shaft housing 1 is the left end thereof.

In some embodiments, as shown in fig. 1, the first heat retainer 200 is a cylindrical structure, and the first heat retainer 200 is sleeved on the shaft housing 1. A first heat-insulating chamber is defined between the inner wall surface of the first heat-insulator 200 and the outer peripheral surface of the shaft housing 1.

In some embodiments, as shown in fig. 1, a first fin 220 is formed on an inner wall surface of the first thermal insulation cavity, and the first phase change material 210 is in contact with the first fin 220. The first fins 220 can increase the heat exchange area of the first phase change material 210. The heat exchange area of the first phase change material 210 refers to an area where the first phase change material 210 can exchange heat. The area of the inner wall surface of the first heat preservation cavity is increased due to the arrangement of the first fins 220, and the first phase change material 210 can exchange heat with the inner wall surface of the first heat preservation cavity, so that the arrangement of the first fins 220 can improve the heat exchange efficiency of the first phase change material 210, the improvement of the heat exchange efficiency can enable the first phase change material 210 to absorb more heat within a certain time, the influence of temperature difference on the magnetic liquid sealing device 100 can be further reduced, and the sealing effect of the magnetic liquid sealing device 100 is improved.

Alternatively, as shown in fig. 1, the first fin 220 is plural. Further alternatively, the extending direction of the first fins 220 is perpendicular to the axial direction of the rotating shaft 2.

In some embodiments, as shown in fig. 1, a first injection hole 230 is formed on the first heat retainer 200, and the first injection hole 230 communicates with the outside and the first heat retaining chamber. The first injection hole 230 is used to inject the first phase change material 210 into the first adiabatic chamber. It is understood that after the injection of the first phase change material 210 is completed, the first injection hole 230 is closed. Alternatively, the first injection hole 230 may be closed with a rubber stopper to prevent leakage of the first phase change material 210.

In some embodiments, as shown in fig. 1, magnetic liquid seal apparatus 100 further comprises end cap 9 and second warmer 300. The end cover 9 is installed on one end (right end) of the shaft housing 1, namely the end cover 9 is connected with the right end of the shaft housing 1, and the rotating shaft 2 extends into the shaft chamber 11 from a through hole formed in the end cover 9.

The second heat retainer 300 is disposed on the outer surface of the end cover 9 (i.e., the side away from the axle housing 1), and the second heat retainer 300 has a second heat retaining cavity or the second heat retainer 300 and the outer surface of the end cover 9 define a second heat retaining cavity therebetween, and the second heat retaining cavity is filled with a second phase change material 310. The second heat retainer 300 is provided to better retain heat of the magnetic liquid sealing apparatus 100 and improve the sealing effect of the magnetic liquid sealing apparatus 100.

In some embodiments, as shown in fig. 1, the second heat-preserving chamber has a second fin 320 formed on an inner wall surface thereof, and the second phase change material 310 is in contact with the second fin 320. The second fins 320 can increase the heat exchange area of the second phase change material 310. The heat exchange area of the second phase change material 310 refers to an area where the second phase change material 310 can exchange heat. The area of the inner wall surface of the second heat preservation cavity is increased due to the arrangement of the second fins 320, and the second phase change material 310 can exchange heat with the inner wall surface of the second heat preservation cavity, so that the heat exchange efficiency of the second phase change material 310 can be improved due to the arrangement of the second fins 320, and the second phase change material 310 can absorb more heat within a certain time due to the improvement of the heat exchange efficiency, so that the influence of temperature difference on the magnetic liquid sealing device 100 can be further reduced, and the sealing effect of the magnetic liquid sealing device 100 is improved.

Optionally, as shown in fig. 1, the second fin 320 is multiple. Further alternatively, the second fins 320 may extend in the same direction as the axial direction of the rotation shaft 2.

In some embodiments, as shown in fig. 1, a second filling hole 330 is formed on the second heat retainer 300, and the second filling hole 330 communicates with the outside and the second heat retaining chamber. The second injection hole 330 is used to inject the second phase change material 310 into the second insulated chamber. It is understood that the second injection hole 330 is closed after the second phase change material 310 is injected. Alternatively, the second injection hole 330 may be closed with a rubber stopper to prevent leakage of the second phase change material 310.

Optionally, the second phase change material 310 is a solid-liquid phase change material.

Optionally, the sealed housing 7 is connected to the left end of the shaft housing 1. The seal chamber body 7 defines a seal chamber 71. The joint of the shaft housing 1 and the seal cavity 7 forms a seal, and since the structural members inside the shaft housing 1 have sealing properties, the seal medium in the seal cavity 71 can be encapsulated by mounting the shaft housing 1 on the seal cavity 7.

Optionally, the sealing medium is a gas or a liquid.

In some embodiments, as shown in fig. 1, the outer circumferential surface of the shaft housing 1 is formed with a flange 12. The first warmer 200 has a first end and a second end in the axial direction of the rotating shaft 2. The first end is the left end of the first warmer 200, and the second end is the right end of the first warmer 200. The first end of the first heat retainer 200 extends in the vertical direction away from the rotating shaft 2 to form a mounting part, the mounting part is connected with the flange 12 of the shaft housing 1, and the second end of the first heat retainer 200 is connected with the end cover 9.

In some embodiments, the shaft housing 1 is mounted to the sealed housing 7 by a flange 12. The magnetic fluid seal 100 comprises a fifth sealing ring 72, wherein the fifth sealing ring 72 is located between the flange 12 and the seal cavity 7. The fifth sealing ring 72 is used for sealing connection of the shaft housing 1 and the sealing cavity 7.

In some embodiments, as shown in fig. 2-4, the axle housing 1 includes a first end cap 13, a housing 14, and a resilient member 15.

The housing 14 has a first positioning portion 141, the first positioning portion 141 includes a positioning table 1411 extending in a radial direction of the housing 14 and a first portion 1412, the first portion 1412 is provided on a first end surface of the positioning table 1411 (e.g., a left end surface of the positioning table 1411), the positioning table 1411 of the housing 14 is provided on the first end cover 13, the first end cover 13 is opposite to the first portion 1412 of the housing 14 in a radial inward and outward direction of the housing 14, the first end cover 13 is provided spaced apart from the first portion 1412 of the housing 14 in the radial inward and outward direction of the housing 14, so that the housing 14 is movable in the radial inward and outward direction relative to the first end cover 13, wherein at least one of the positioning table 1411 and the first end cover 13 is provided with a mounting groove 16. Elastic member 15 is disposed within mounting slot 16, and elastic member 15 is in a compressed state, wherein a portion of elastic member 15 protrudes through mounting slot 16, and the portion of elastic member 15 engages with at least one of positioning table 1411 and first end cap 13, respectively.

The first end cap 13 is arranged at a distance from the first part 1412 of the housing 14 in the inner-outer direction, i.e. a gap is left between the inner side of the first end cap 13 and the outer side of the housing 14, so that the housing 14 can move in the gap. When the magnetic liquid sealing device 100 is used, if the rotating shaft 2 makes radial runout, the rotating shaft 2 drives the housing 14 to make radial runout in the gap, so that the deformation pressure of the housing 14 is reduced, the pressure on the bearing installed in the housing 14 can be reduced, and the bearing is prevented from being damaged.

Optionally, the first end cap 13 is spaced from the first portion 1412 of the housing 14 by a distance of 0.101mm to 1.999mm or 2.001mm to 20mm in the radially inner and outer direction of the housing 14.

By providing the elastic member 15, the elastic member 15 can support the housing 14, thereby adjusting the pressure between the housing 14 and the first end cap 13. Therefore, the elastic element 15 can reduce the pressure applied to the sealing ring between the casing 14 and the first end cap 13, and reduce the wear of the sealing ring, thereby prolonging the service life of the sealing ring, further ensuring the sealing performance of the magnetic liquid sealing device 100, and reducing the friction area between the casing 14 and the opposite end surface of the first end cap 13 during the radial runout of the rotating shaft 2, reducing the noise, and simultaneously reducing the degree of damage to the casing 14 and the first end cap 13. The resilient member 15 is also capable of providing a resilient force during radial runout of the shaft 2, maintaining the gap between the pole piece 4 and the shaft 2 substantially constant.

By arranging the elastic member 15 in the mounting groove 16, the elastic member 15 can be prevented from being exposed to the external environment, the elastic member 15 can be effectively prevented from being damaged, the elastic member 15 can be protected, the service life of the elastic member 15 can be prolonged, and the sealing performance of the magnetic liquid sealing device 100 can be ensured.

As an example, as shown in fig. 2-4, a first sealing ring 17 is provided between the positioning table 1411 and the first end cap 13. The first sealing ring 17 has a sealing function, the first sealing ring 17 can prevent leakage of a sealing medium, the elastic part 15 can adjust pressure acting on the first sealing ring 17, abrasion of the first sealing ring 17 is reduced, the service life of the first sealing ring 17 is prolonged, and sealing performance of the magnetic liquid sealing device 3 is further ensured.

Optionally, a first end face of the first end cover 13 (for example, a left end face of the first end cover 13) is provided with a second end cover 18, the second end cover 18 has a second positioning portion 181 and a clamping portion 182, the second positioning portion 181 is located inside the clamping portion 182, the second end cover 18 is mounted on the housing 14 through bolts or screws, so that the second end cover 18 and the housing 14 cooperate to clamp the first end cover 13 on the housing 14, and an inner ring diameter of the second positioning portion 181 is smaller than an inner ring diameter of the housing 14, so that the second positioning portion 181 positions a device in the housing 14.

Optionally, a second sealing ring 19 is provided between the first end cap 13 and the second end cap 18. The leakage of the sealed medium is further prevented and the second seal ring 19 reduces the contact surface between the first and second end caps 13 and 18, further reducing noise. The second end cover 18 is mounted on the housing 14 through a screw or a bolt, so that the second end cover 18 is not only convenient to detach from the housing 14, but also can adjust the pressure borne by the second sealing ring 19, and the second sealing ring 19 is prevented from being damaged, thereby prolonging the service life of the second sealing ring 19.

In some embodiments, as shown in fig. 2-4, the first portion 1412 is a locating sleeve extending in an axial direction of the housing 14, and the first end cap 13 is disposed outside the first portion 1412 of the housing 14 or the first portion 1412 of the housing 14 is disposed outside the first end cap 13. Particularly, the diameter of the inside surface of first end cover 13 is greater than the diameter of the outside surface of position sleeve for first end cover 13 can be sheathe in the position sleeve, and is equipped with the clearance (as shown in fig. 2) between position sleeve outside surface and the 13 inside surface of first end cover, thereby makes casing 14 can remove in radial inside and outside direction first end cover 13 relatively, makes things convenient for first end cover 13 to dismantle and install moreover, makes the structure of magnetic liquid sealing device's shell more reasonable. Or the diameter of the inner side surface of the positioning sleeve is larger than that of the outer side surface of the first end cover 13, so that the positioning sleeve is sleeved on the first end cover 13, and a gap (as shown in fig. 4) is formed between the inner side surface of the positioning sleeve and the outer side surface of the first end cover 13, so that the shell 14 can move in the radial inner and outer directions relative to the first end cover 13.

In other embodiments, the first portion 1412 is a positioning block or a positioning sleeve extending along the axial direction of the housing 14, a positioning groove is formed on an end surface of the first end cap 13 opposite to the positioning table 1411 along the circumferential direction of the housing 14, the first portion 1412 extends into the positioning groove, and a gap is formed between the first portion 1412 and a side surface of the positioning groove. Specifically, the first portion 1412 is provided with gaps to both side surfaces of the positioning groove, which enables the housing 14 to move in the radial inward and outward directions with respect to the first endcap 13.

In some embodiments, as shown in fig. 3, the end surface of the first end cap 13 opposite to the housing 14 is provided with a mounting groove 16, and a portion of the elastic member 15 is engaged with the housing 14. In other words, the elastic member 15 is disposed in the mounting groove 16 of the first end cap 13, and a portion of the elastic member 15 extends out of the mounting groove 16 to be engaged with the housing 14, so that the elastic member 15 can support the housing 14 so that the housing 14 is not in contact with the first end cap 13. The elastic piece 15 not only can reduce the pressure of the shell 14 on the first sealing ring 17, but also can adjust the pressure acting on the first sealing ring 17 by changing the number and the rigidity of the elastic pieces 15, thereby prolonging the service life of the first sealing ring 17, and further effectively solving the problem of sealing part damage caused by the runout of the rotating shaft 2, the elastic piece 15, the first sealing ring 17 and the second sealing ring 19 generate intervals on the contact end surfaces of the shell 14 and the first end cover 13 and the contact end surfaces of the first end cover 13 and the second end cover 18, the friction between the end surfaces can be reduced, the noise can be reduced, and the elasticity of the elastic piece 15 can be utilized to play a role of buffering the runout of the shell 14 in the radial direction, the rebound force can be provided when the shaft jumps in the radial direction, and the gap between the whole pole shoe 4 and the rotating shaft 2 is kept basically stable.

In some embodiments, the mounting grooves 16 are uniformly distributed in a plurality along the circumferential direction of the housing 14, the elastic members 15 are provided in a plurality, the elastic members 15 are correspondingly arranged in the mounting grooves 16 one by one, the shape of the elastic members 15 is matched with the inner surface of the mounting grooves 16, and the elastic members 15 are prevented from shaking in the mounting grooves 16; optionally, the elastic member 15 is a spring or a compression spring. The plurality of elastic members 15 can provide a stronger supporting function to the housing 14, thereby making it possible to make the housing of the magnetic liquid seal apparatus more stable, and the pressure acting on the first seal ring 17 can be adjusted by changing the number and rigidity of the elastic members 15, thereby adjusting the service life of the first seal ring 17, and also increasing the buffering capacity of the elastic members 15, thereby ensuring the sealing performance of the magnetic liquid seal apparatus 100. Alternatively, the mounting slot 16 is a circular hole, so that the mounting slot 16 matches the shape of the elastic member 15.

In other embodiments, the mounting groove 16 is an annular groove, the circumference of the mounting groove 16 is consistent with the circumference of the housing 14, and the elastic member 15 is annular. Alternatively, the elastic member 15 is a coil spring. This reduces the difficulty of mounting the elastic member 15, and increases the stability of the housing of the magnetic fluid sealing apparatus 100.

In some embodiments, as shown in fig. 1, the pole piece 4 includes a first pole piece 41 and a second pole piece 42, and the permanent magnet 6 includes a first permanent magnet located between the first pole piece 41 and the second pole piece 42 in an axial direction of the rotating shaft 2. That is, the right side surface of the first pole piece 41 abuts against the left side surface of the first permanent magnet, and the right side surface of the first permanent magnet abuts against the left side surface of the second pole piece 42. The first permanent magnet is used to provide a magnetic force to the first and

second pole pieces

41 and 42 so that the first and

second pole pieces

41 and 42 attract the magnetic liquid 43. Each of the first pole piece 41, the second pole piece 42 and the permanent magnet 6 is connected to a peripheral wall surface of the shaft chamber.

In some embodiments, as shown in fig. 1, the magnetic liquid seal device 100 further comprises a first magnetic shield 101 and a second magnetic shield 102. The first pole piece 41 and the second pole piece 42 are located between the first magnetism isolating sleeve 101 and the second magnetism isolating sleeve 102 in the axial direction of the rotating shaft 2, the first magnetism isolating sleeve 101 abuts against the first pole piece 41, and the second magnetism isolating sleeve 102 abuts against the second pole piece 42. The first magnetic shield 101 and the second magnetic shield 102 can prevent magnetic lines of force emitted by the permanent magnet 6 from leaking from both sides of the pole piece 4.

In some embodiments, as shown in fig. 1, the magnetic fluid sealing device 100 further includes a first bearing 31 and a second bearing 32, each of the first bearing 31 and the second bearing 32 is fitted over the rotating shaft 2, and the first bearing 31 and the second bearing 32 are spaced in an axial direction along the rotating shaft 2.

In some embodiments, as shown in fig. 1, each of the first pole piece 41, the second pole piece 42, the permanent magnet 6, the first flux barrier 101, and the second flux barrier 102 is located between the first bearing 31 and the second bearing 32 in an axial direction along the rotating shaft 2. The other end (left end) of the shaft housing is formed with a first protrusion 8, one side (left side) of the first bearing 32 in the axial direction of the rotating shaft 2 abuts against the protrusion 8, the other side (right side) of the first bearing 32 in the axial direction of the rotating shaft abuts against the first magnetism isolating sleeve 101, and the left side of the second bearing 31 abuts against the second magnetism isolating sleeve 102. The right side of the second bearing 31 abuts the end cap 9.

That is, the first magnetism isolating sleeve 101 abuts against the first bearing 31 and the first pole piece 41 at opposite ends in the axial direction of the rotating shaft 2, and the second magnetism isolating sleeve 102 abuts against the second pole piece 42 and the second bearing 32 at opposite ends in the axial direction of the rotating shaft 2.

In some embodiments, as shown in fig. 1, the magnetic liquid sealing apparatus 100 further includes a third sealing ring 103 and a fourth sealing ring 104, the third sealing ring 103 is located between the outer circumferential surface of the first pole piece 41 and the circumferential wall surface of the shaft chamber 11, and the fourth sealing ring 104 is located between the outer circumferential surface of the second pole piece 42 and the circumferential wall surface of the shaft chamber 11. The third seal ring 103 and the fourth seal ring 104 are used to improve the sealing performance between the outer circumferential surfaces of the first pole piece 41 and the second pole piece 42 and the circumferential wall surface of the shaft chamber 11.

Alternatively, the first seal ring 17, the second seal ring 19, the third seal ring 103, the fourth seal ring 104, or the fifth seal ring 72 may be one of an O-ring, a V-ring, and a U-ring.

In some embodiments, as shown in fig. 1, the magnetic liquid sealing device 100 further includes a clamp spring 5, and the clamp spring 5 is sleeved on the rotating shaft 2 and used for fixing and limiting the components in the shaft chamber 11, so as to prevent the components in the shaft chamber 11 from moving, and improve the stability of the magnetic liquid sealing device 100.

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 magnetic fluid seal assembly, comprising:

a shaft housing defining a shaft chamber;

the rotating shaft is rotatably arranged in the shaft chamber and extends into the shaft chamber from one end of the shaft shell and extends out from the other end of the shaft shell;

the first heat retainer is arranged on the outer peripheral surface of the shaft shell, the first heat retainer is provided with a first heat retaining cavity or a first heat retaining cavity is defined between the first heat retainer and the outer peripheral surface of the shaft shell, a first phase-change material is filled in the first heat retaining cavity, a fin is formed on the inner wall surface of the first heat retaining cavity, and the first phase-change material is in contact with the fin;

the pole shoe is sleeved on the rotating shaft, the outer peripheral surface of the pole shoe is connected with the peripheral wall surface of the shaft chamber, a plurality of pole teeth are arranged on the inner peripheral surface of the pole shoe along the axial direction of the rotating shaft, tooth grooves are formed between every two adjacent pole teeth, magnetic liquid for sealing is arranged between the tooth top surface of each pole tooth and the peripheral surface of the rotating shaft, and the magnetic liquid is adsorbed on the tooth top surface;

the permanent magnet is sleeved on the rotating shaft, the permanent magnet is matched with the pole shoe, and each of the pole shoe and the permanent magnet is positioned in the shaft chamber;

and the shaft shell is connected with the seal cavity.

2. The magnetic liquid sealing device according to claim 1, wherein a first filling hole is formed in the first heat retainer, and the first filling hole communicates with the outside and the first heat-insulating cavity.

3. The magnetic fluid seal apparatus of claim 1, further comprising:

an end cap mounted on the one end of the axle housing;

and the second heat retainer is arranged on the outer surface of the end cover, a second heat retaining cavity is defined between the second heat retainer and the outer surface of the end cover, and second phase change materials are filled in the second heat retaining cavity.

4. The magnetic liquid sealing device according to claim 3, wherein a fin is formed on an inner wall surface of the second heat-preservation cavity, the second phase-change material is in contact with the fin, a second injection hole is formed in the second heat retainer, and the second injection hole is communicated with the outside and the second heat-preservation cavity.

5. The magnetic fluid seal apparatus of claim 1, wherein said shaft housing comprises:

a first end cap;

a housing having a first positioning portion including a positioning table extending in a radial direction of the housing and a first portion provided on a first end surface of the positioning table, the positioning table of the housing being provided on a first end cover opposed to the first portion of the housing in a radial inward-outward direction of the housing, the first end cover being provided spaced apart from the first portion of the housing in the radial inward-outward direction of the housing so that the housing is movable in the radial inward-outward direction relative to the first end cover, wherein at least one of the positioning table and the first end cover is provided with a mounting groove; and

an elastic member disposed within the mounting slot, the elastic member being in a compressed state, wherein a portion of the elastic member extends out of the mounting slot, the portion of the elastic member cooperating with a respective at least one of the positioning table and the first end cap.

6. The magnetic fluid seal apparatus of claim 5, wherein said first portion is a positioning sleeve extending along an axial direction of said housing, said first portion of said housing being fitted over an outer side of said first end cap; or

The first part is along the locating piece that casing axial direction extends, first end cover with be equipped with on the relative terminal surface of location platform along the constant head tank of the circumference direction of casing, the first part stretches into in the constant head tank, just the first part with the side of constant head tank is equipped with the clearance.

7. The magnetic fluid seal apparatus of claim 5, wherein said mounting groove is provided on an end surface of said first end cap opposite to said housing, said portion of said elastic member engaging with said housing.

8. The magnetic liquid sealing device according to claim 7, wherein a plurality of mounting grooves are uniformly distributed along the circumferential direction of the housing, the plurality of elastic members are arranged in the mounting grooves in a one-to-one correspondence manner, and the outer shape of each elastic member is matched with the inner surface of the mounting groove; or, the mounting groove is an annular groove, the circumferential direction of the mounting groove is consistent with the circumferential direction of the shell, and the elastic piece is annular.

9. The magnetic fluid seal apparatus of claim 5, wherein the first end face of the first end cap is provided with a second end cap, the second end cap has a second positioning portion and a clamping portion, the second positioning portion is located inside the clamping portion, the second end cap is mounted on the housing through a bolt or a screw, so that the second end cap and the housing cooperate to clamp the first end cap on the housing, and an inner diameter of the first positioning portion is smaller than an inner diameter of the housing, so that the second positioning portion positions the apparatus in the housing.

10. The magnetic liquid seal apparatus according to claim 1, wherein the pole pieces include a first pole piece and a second pole piece, the permanent magnets include a first permanent magnet located between the first pole piece and the second pole piece in an axial direction of the rotating shaft, each of the first pole piece, the second pole piece, and the first permanent magnet being connected to a peripheral wall surface of the shaft chamber;

the magnetic liquid sealing device further includes:

the first pole shoe and the second pole shoe are positioned between the first magnetic isolation sleeve and the second magnetic isolation sleeve along the axial direction of the rotating shaft, the first magnetic isolation sleeve is abutted against the first pole shoe, and the second magnetic isolation sleeve is abutted against the second pole shoe;

the bearing comprises a first bearing and a second bearing, each of the first bearing and the second bearing is sleeved on the rotating shaft, and the first bearing and the second bearing are arranged at intervals in the axial direction of the rotating shaft.

11. The magnetic liquid sealing device according to claim 10, wherein each of the first pole piece, the second pole piece, the permanent magnet, the first magnetic shield, and the second magnetic shield is located between the first bearing and the second bearing in an axial direction of the rotating shaft, the other end of the shaft housing is formed with a projection, the first bearing abuts against the projection on one side in the axial direction of the rotating shaft, the first bearing abuts against the first magnetic shield on the other side in the axial direction of the rotating shaft, and the second bearing abuts against the second magnetic shield.