CN112833191A

CN112833191A - Sealing method

Info

Publication number: CN112833191A
Application number: CN202110083401.8A
Authority: CN
Inventors: 王前进
Original assignee: Wuhan Boymai Technology Co ltd
Current assignee: Wuhan Boymai Technology Co ltd
Priority date: 2021-01-21
Filing date: 2021-01-21
Publication date: 2021-05-25

Abstract

The invention discloses a sealing method, which comprises a salient pole and a concave pole, wherein the salient pole and the concave pole are respectively fixed on a pair of coaxial rotatable parts; the concave pole is in an annular structure, the outer side of the concave pole is provided with a permanent magnet, and the inner side of the concave pole is provided with a U-shaped or V-shaped groove; the tops of the salient poles are arranged in the grooves, and U-shaped or V-shaped gaps are formed between the salient poles and the grooves; magnetic fluid is filled in the gap; the magnetic fluid is accumulated at the bottom of the groove under the action of a magnetic field provided by the magnetic pole at the inner side of the permanent magnet, and a U-shaped or V-shaped sealing strip is formed between the salient pole and the concave pole by utilizing the principle of static pressure balance of the fluid in the U-shaped pipe; the concave pole or the convex pole in the rotating state drives the magnetic fluid to rotate, so that the magnetic fluid generates centrifugal force, and the static pressure balance of the magnetic fluid is realized under the equidirectional superposition effect of the centrifugal force and the magnetic force. The sealing method provided by the invention combines the principle of static pressure balance of fluid in the U-shaped pipe, and improves the sealing effect of the magnetic fluid by utilizing the centrifugal force generated when the fluid rotates.

Description

Sealing method

Technical Field

The invention belongs to the field of mechanical engineering sealing, and particularly relates to a sealing method with self-adjustability and suitable for high rotating speed.

Technical Field

The magnetic fluid is used as a special functional material, is applied to various fields at present, is a colloidal system formed by uniformly dispersing ferromagnetic particles in a carrier fluid, has both strong magnetism and fluidity, can keep long-term stability under the action of various forces such as gravity, magnetic force and the like, does not generate precipitation and layering, plays a huge role in mechanical sealing, and has the principle that the magnetic fluid is restrained by a magnetic field to fill a sealing space to form a liquid O-shaped sealing ring, and the proper carrier fluid can well infiltrate the sealing surface to achieve a very good sealing effect. Based on the special properties of the magnetic fluid, the magnetic fluid seal has the following advantages: 1. the sealing performance is good and the repair is easy; 2. no abrasion, long service life and low power consumption; 3. simple structure, low cost and high reliability.

Although the magnetic fluid has many advantages, but also has disadvantages, the existing magnetic fluid dynamic sealing structure comprises a static magnetic pole and a rotary magnetic pole, the magnetic fluid is restrained in a magnetic circuit gap formed by the static magnetic pole and the rotary magnetic pole by the axial magnetic pull force of the two magnetic poles to form sealing, in the operation process, the magnetic fluid generates radial outward centrifugal force on a rotating surface because of rotation, the magnetic fluid in the operation process breaks away from the constraint of magnetic force to generate depression due to the action of the centrifugal force, so that the effective sealing thickness of an O-shaped sealing ring of the magnetic fluid is obviously reduced, the sealing performance is poor, and even the sealing failure can be caused in the high-speed operation process.

Disclosure of Invention

In order to overcome the defects of the prior art, the invention combines the principle of static pressure balance of fluid in the U-shaped pipe and utilizes the centrifugal force generated by the rotation of the fluid to provide a sealing method which has self-regulation performance and is suitable for high rotating speed.

In order to achieve the purpose, the invention adopts the technical scheme that:

a sealing method comprises a salient pole and a concave pole which are respectively fixed on a pair of coaxial and at least one rotatable components; the concave pole is of an annular structure, the outer side of the concave pole is provided with a permanent magnet, and the inner side of the concave pole is provided with a U-shaped or V-shaped groove; the tops of the salient poles are arranged in the grooves, and U-shaped or V-shaped gaps are formed between the salient poles and the grooves; magnetic fluid is filled in the gap; the magnetic fluid is accumulated at the bottom of the groove under the action of a magnetic field provided by the magnetic poles at the inner side of the permanent magnet, and a U-shaped or V-shaped sealing strip is formed between the salient pole and the concave pole by utilizing the principle of static pressure balance of the fluid in the U-shaped pipe; the concave pole or the convex pole in a rotating state drives the magnetic fluid to rotate, so that the magnetic fluid generates centrifugal force, the static pressure balance of the magnetic fluid is realized under the equidirectional superposition effect of the centrifugal force and the magnetic force, the external pressure difference is resisted, and the faster the rotating speed is, the stronger the resisting capability is; the beneficial effects are that: the structural forms of the salient pole and the concave pole jointly create a gap with a U-shaped section, and magnetic fluid is filled in the gap; the magnetic poles on the inner side of the permanent magnet provide a radial magnetic field for the magnetic fluid in a close distance, so that the two ends of the magnetic fluid generate a potential energy moving radially outwards, the magnetic fluid is further promoted to be accumulated at the bottom of the groove to form a sealing strip, the static pressure balance of the fluid in the U-shaped pipe is realized, the sealing strip is wholly deviated to achieve new balance under the condition that the pressure difference exists between the two ends of the magnetic fluid, the sealing surface cannot be damaged, and the sealing effect is not influenced; when the salient pole or the concave pole in a rotating state drives the magnetofluid to rotate, the magnetofluid can generate centrifugal force, the direction of the centrifugal force is also outward in the radial direction, the magnetofluid enhances the potential accumulated to the bottom of the concave pole under the equidirectional superposition effect of the magnetic force and the centrifugal force, according to the principle of static pressure balance of the fluid in the U-shaped tube, the pressure difference between two ends of the magnetofluid is zero, when the pressure difference is not zero, the magnetofluid can be wholly deviated in a gap to form liquid level height difference between two ends, so that the balanced pressure difference is realized, the higher the rotating speed is, the larger the centrifugal force is, the extremely small liquid level height difference can resist extremely strong external pressure difference, the extremely good dynamic sealing effect can be ensured, the problem that the sealing thickness is stretched and thinned and punctured due to the influence of the centrifugal force of the magnetofluid in a high-speed state is not worried about, the stronger the capacity of resisting the external pressure difference, the more suitable the working condition that the external pressure difference increases along with the increase of the rotating speed, and the self-regulation capacity is strong; according to the physical relation among pressure, pressure intensity and area, in order to further increase the capacity of the magnetic fluid for resisting external pressure difference under the influence of magnetic force, the flow area at the U-shaped gap is smaller towards the bottom.

Preferably, a carrier liquid strip for increasing the contact area with the magnetic fluid is arranged in the gap and is fixed on the rotating part; the beneficial effects are that: the liquid carrying bar is used as an extension part of the concave pole or the convex pole, so that the surface contact area of the concave pole or the convex pole and the magnetic fluid is indirectly increased, the capacity of the concave pole or the convex pole for driving the magnetic fluid to rotate is enhanced, the magnetic fluid can obtain more energy to rotate, and a larger centrifugal force is generated; the carrier liquid bar can be made of a material with a sponge structure, such as high-density sponge, and is mainly characterized by flexibility and porosity, fluid can freely shuttle in pores of the carrier liquid bar without affecting the fluidity of the carrier liquid bar and further without affecting the sealing effect of the fluid, and more importantly, the sponge structure of the carrier liquid bar is criss-cross, so that the capacity of the rotating part for driving the magnetic fluid to rotate is greatly increased; in general, the carrier strip may be replaced with batt fiber or down for cost savings.

Preferably, the permanent magnet is in an annular structure, is magnetized by radiation and is a monopole radiation ring; the beneficial effects are that: the magnetic poles of the monopole radiation ring are respectively positioned at the inner side and the outer side, as is known, the magnetic poles are the parts with the strongest magnetic force in the magnet, the magnetic induction lines are distributed most densely, the magnetic field lines which are closer to the magnetic poles at the inner side of the annular permanent magnet are in a radial distribution state, the grooves are tightly attached to the magnetic poles at the inner side of the annular permanent magnet and are positioned at the center, so that the whole magnetic fluid sealing strip is positioned at the optimal position where the magnetic poles provide the magnetic field in a short distance, the maximum radial magnetic force can be obtained, the magnetic fluid is further promoted to be accumulated at the bottom of the grooves to form the sealing strip, the static. The permanent magnet can be formed by combining a plurality of fan-shaped permanent magnets in a staggered manner, a radiation ring can be adopted for the annular permanent magnet with a small radius, the processing is easy, but the processing is not easy for the annular permanent magnet with a large diameter, and the processing difficulty can be reduced by adopting a combined manner; in order to make the magnetic field distribution more uniform, the sector permanent magnets are arranged in a staggered manner, and a radiation magnetizing or radial magnetizing mode is adopted.

Preferably, the permanent magnet and the concave pole are connected into a whole and fixed on the rotating part, and the salient pole is fixed on the static part; the beneficial effects are that: the permanent magnet and the concave pole are connected into a whole to further shorten the distance between the magnetic pole and the magnetic fluid, so that the magnetic fluid can obtain larger magnetic force and generate stronger sealing performance; the concave pole is fixed on the rotating component, on one hand, the magnetic fluid is accumulated towards the bottom of the groove under the action of a magnetic field, the magnetic particles in the magnetic fluid are distributed unevenly under the action of the magnetic field, the concentration of the magnetic particles is denser at the part closer to the magnetic pole, and further the part closer to the magnetic pole is, the viscosity of the magnetic fluid is higher, compared with the salient pole, the concave pole rotates to drive the magnetic fluid to obtain centrifugal force, so that the sealing performance is higher in a dynamic sealing state, and the viscosity of the magnetic fluid close to the salient pole is small, the friction force between the magnetic fluid and the salient pole is small during rotation, and the heat generated during operation is relatively small; on the other hand, in the sealing structure, the concave part is arranged at the outer ring of the salient pole, the surface contact area of the concave pole and the magnetic fluid is larger than that of the salient pole and the magnetic fluid, the generated static friction force is large, the transmitted energy is large, the capacity of driving the magnetic fluid to rotate is better than that of the salient pole, and in the rotating process, the speed of the concave pole line at the outer ring is larger than that of the salient pole at the inner ring, the generated centrifugal force is larger, and the resistance to external pressure difference is better facilitated; the concave pole is preferably made of flexible materials, such as high-elasticity polymers with strong plasticity, more specifically polytetrafluoroethylene, which is resistant to high temperature and low temperature, and when the concave pole is made of flexible materials, the annular permanent magnet can be used as a support to provide powerful support for the concave pole, so that the concave pole is ensured not to deform during high-speed operation, the sealing effect is further ensured, and the number of parts is reduced; it is especially pointed out that, because the magnetic poles of the permanent magnet are respectively positioned at the inner side and the outer side, the inner side magnetic pole provides a magnetic field for the magnetic fluid, and the outer side magnetic pole can also provide a magnetic field, if a U-shaped gap is formed in the outer space of the permanent magnet, the magnetic grease can be filled in the non-Newtonian magnetic fluid with high viscosity and low cost, and an auxiliary sealing strip is formed under the action of centrifugal force.

Preferably, the outer end of the rotating ring is provided with a separation plate, and the separation plate is fixed on the static part; the beneficial effects are that: the labyrinth type sealing structure is formed, a U-shaped gap is formed at the periphery of the permanent magnet, lubricating grease, preferably magnetic lubricating grease, can be filled in the gap, and auxiliary sealing is formed by fully utilizing the centrifugal effect generated when the rotating ring operates and the strong magnetic attraction of the magnetic pole of the permanent magnet to the magnetic lubricating grease, so that the sealing performance is improved.

Preferably, a mud throwing ring is arranged on the outer side of the isolation plate, and the isolation plate is fixed on the rotating component; the beneficial effects are that: when waterproof sealing is done, the rotatory mud ring that gets rid of at a high speed can utilize the effect of centrifugal force to throw away large granule impurity such as silt of aquatic, avoids impurity to get into the fluid seal area in, influences sealing performance.

Preferably, the edge of the concave pole is in contact with the salient pole to form a closed space, and the magnetic fluid is limited in the closed space of a U shape or a V shape formed between the salient pole and the concave pole; the beneficial effects are that: on one hand, the magnetic fluid can be prevented from being greatly leaked out when the magnetic fluid is separated from the constraint of magnetic force during violent vibration; on the other hand, the magnetic fluid sealing device can prevent external impurities from entering the magnetic fluid to influence the characteristics of the magnetic fluid and ensure the sealing effect.

Preferably, the salient poles are fixed on the rotating member; the permanent magnet and the concave pole are connected into a whole and fixed on the static part; the beneficial effects are that: the magnetic field generator is suitable for occasions where the exciting body needs to be arranged on the outer side of the permanent magnet, the connection of a winding coil on the exciting body is convenient, the rotating salient poles drive the magnetic fluid to rotate, and the fluid generates centrifugal force.

Preferably, an exciter wound with a coil is arranged on the outer side of the permanent magnet, and the exciter generates a magnetic field after the coil is electrified to provide magnetic force; the excitation body is fixed on the static component; the beneficial effects are that: the exciter with the coil generates a magnetic field after being electrified, the intensity change of the magnetic field generated by the exciter can be controlled by changing the current, so that the sealing intensity is controllable, the exciter is suitable for working occasions with special requirements, and further, the exciter with the coil is fixedly arranged on a static part outside the concave pole, thereby facilitating the connection of a circuit.

Further preferably, the exciter comprises excitation columns and excitation rings, and the excitation columns wound with coils are uniformly distributed on the excitation rings; the beneficial effects are that: the excitation column wound with the coil is electrified to provide a magnetic field, and the excitation ring distributes the magnetic field along the circumference, so that the distribution uniformity of the magnetic fluid is ensured, and the sealing effect is further ensured; it should be noted that the excitation body with large diameter can be made in a form of split combination and staggered arrangement.

Compared with the prior art, the invention has the beneficial effects that: 1. the method for sealing the magnetic fluid by binding the magnetic fluid in the air gap of the magnetic circuit through axial magnetic tension in the conventional method is broken through, the magnetic fluid is applied with a magnetic force which faces outwards in the radial direction, and the magnetic fluid is promoted to form a U-shaped sealing strip by utilizing the principle of static pressure balance of the fluid in a U-shaped pipe, so that the sealing strip not only ensures the characteristic of a low friction pair of the magnetic fluid, but also eliminates the risk of sealing failure caused by the action of centrifugal force of the magnetic fluid; 2. the centrifugal force is changed from the harmful surface to the beneficial surface, the higher the rotating speed is, the larger the centrifugal force is, the stronger the sealing effect is, the underwater propeller is particularly suitable for being applied, and the self-adjustment performance is strong; 3. the related parts have simple structures and low manufacturing cost; 4. the magnetic fluid sealing has the advantages of no abrasion, long service life and low power consumption.

Drawings

FIG. 1 is a schematic structural diagram illustrating a sealing method according to a first embodiment;

FIG. 2 is a schematic structural diagram of an integrated design of the salient pole and the support ring in the first embodiment;

FIG. 3 is a schematic structural diagram of the monopole radiating ring according to the first embodiment;

FIG. 4 is a schematic structural diagram of a permanent magnet according to the first embodiment in a combined form;

FIG. 5 is a schematic structural diagram of the recess and carrier bar according to one embodiment;

FIG. 6 is a schematic view showing an equilibrium state in the presence of a pressure difference in the sealing method according to the first embodiment;

FIG. 7 is a schematic structural view of a sealing method according to a second embodiment;

FIG. 8 is a schematic structural view of a sealing method according to a third embodiment;

FIG. 9 is a schematic structural view of a sealing method according to a fourth embodiment;

FIG. 10 is a schematic structural view illustrating a sealing method according to a fifth embodiment;

FIG. 11 is a schematic structural view of a sealing method according to the sixth embodiment;

FIG. 12 is a schematic structural view of a sealing method according to the seventh embodiment;

fig. 13 is a structural schematic diagram of the exciter body in the seventh embodiment in an integrated design;

FIG. 14 is a schematic structural view of a sealing method according to an eighth embodiment;

fig. 15 is a structural schematic view of the exciter body in combination according to the eighth embodiment;

FIG. 16 is a schematic structural view of a sealing method according to the ninth embodiment;

in the figure: 1. salient poles; 2. a magnetic fluid; 3. a concave pole; 4. a permanent magnet; 4-1, magnetic sheets; 5. a rotating ring; 6. carrying a liquid bar; 7. a shaft; 8. a housing; 9. a support ring; 10. throwing mud rings; 11. a limiting part; 12. a positioning frame; 13. a separator plate; 14. magnetic grease; 15. an exciter body; 15-1, excitation columns; 15-2, a coil; 15-3, exciting a magnetic ring; 15-4 and excitation tiles.

Detailed Description

The technical solutions of the present invention will be described clearly and completely with reference to the accompanying drawings, and it is obvious that the described embodiments are only some embodiments of the present invention, not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Example one

As shown in fig. 1-6, a sealing method comprises a salient pole 1 and a concave pole 3 which are respectively fixed on a shell 8 and a shaft 7 which are coaxially arranged, wherein a U-shaped groove is arranged on the concave pole 3; the top of the salient pole 1 is arranged in the U-shaped groove of the concave pole 3, and a U-shaped gap is formed between the salient pole 1 and the concave pole 3; the magnetic fluid 2 is filled in the gap; a permanent magnet 4 is fixed on the outer side of the concave pole 3, the permanent magnet 4 is in an annular structure, is magnetized by radiation and is a monopole radiation ring, and the magnetic pole on the inner side of the permanent magnet 4 generates a magnetic force which is outward in the radial direction on the magnetic fluid 2; the magnetic fluid 2 overcomes the self gravity under the action of radial magnetic force, and a U-shaped magnetic fluid sealing belt is formed between the salient pole 1 and the concave pole 3 by utilizing the principle of static pressure balance of fluid in a U-shaped pipe; the salient pole 1 is fixedly installed in the shell 8 through a support ring 9; the permanent magnet 4 and the concave pole 3 are connected into a whole and fixed on the rotating ring 5, the rotating ring 5 is fixedly arranged on the shaft 7, the shaft 7 rotates to drive the concave pole 3 and the permanent magnet 4 to synchronously rotate, and the concave pole 3 in a rotating state drives the magnetic fluid 2 to rotate so that the magnetic fluid 2 generates a radial outward centrifugal force; the magnetic fluid 2 is accumulated at the bottom of the U-shaped groove of the concave pole 3 under the combined action of centrifugal force and magnetic force; in order to increase the capacity of the recessed electrode 3 for driving the magnetic fluid 2 to rotate, the carrier liquid strips 6 are fixedly bonded in the recessed electrode 3; the outer end of the rotating ring 5 is provided with a separation plate 13, and the separation plate 13 is fixed on the shell 8; magnetic grease 14 is filled in a U-shaped gap formed among the support ring 9, the rotating ring 5, the isolating plate 13 and the shell 8; in order to simplify the processing procedure, the support ring 9 can be designed integrally with the salient pole 1, and the concave pole 3 is formed by injection molding of polytetrafluoroethylene.

According to the principle of static pressure balance of fluid in the U-shaped pipe, when the sealing belt is in a static sealing state, the magnetic fluid 2 keeps balance under the action of a magnetic pole above the concave pole 3; if there is no pressure difference at the two ends of the magnetic fluid 2, the height difference h of the liquid level at the two ends is zero, if the pressure at one end is increased, the magnetic fluid 2 will wholly shift to the side with low pressure until a new balance state is reached, at this moment, the height difference h of the liquid level is formed, and the magnetic fluid 2 in the height difference zone balances the external pressure difference under the action of magnetic force; when the sealing belt is in a dynamic sealing state, the magnetic fluid 2 in a rotating state is acted by magnetic force and centrifugal force, the magnetic fluid and the centrifugal force are mutually superposed to provide a radial force field together to realize the static pressure balance of the U-shaped pipe, the higher the rotating speed is, the larger the centrifugal force is, the extremely small liquid level height difference h can resist extremely strong external pressure difference change, the excellent dynamic sealing effect is ensured, and the problem that the sealing fails because the thickness of the magnetic fluid 2 is thinned and punctured is not needed to be worried about; it should be noted that the magnetic grease 14 is adsorbed on the outer magnetic pole under the action of the permanent magnet 4, and is not easy to leak; when rotating, the rotating ring 5 drives the magnetic lubricating grease 14 to generate centrifugal force, and a sealing belt is formed in the gap to play a role in auxiliary sealing and effectively prevent impurities from entering.

Example two

As shown in fig. 7, a sealing method comprises a salient pole 1 and a concave pole 3 which are respectively fixed on a shell 8 and a shaft 7 which are coaxially arranged, and two U-shaped grooves are arranged on the concave pole 3 for improving the sealing performance of the sealing; the top of the salient pole 1 is arranged in the U-shaped groove of the concave pole 3, and two U-shaped gaps are formed between the salient pole 1 and the concave pole 3; the magnetic fluid 2 is filled in the gap; a permanent magnet 4 is fixed on the outer side of the concave pole 3, the permanent magnet 4 is in an annular structure, is magnetized by radiation and is a monopole radiation ring, and the magnetic pole on the inner side of the permanent magnet 4 generates a magnetic force which is outward in the radial direction on the magnetic fluid 2; the magnetic fluid 2 overcomes the self gravity under the action of radial magnetic force, and a U-shaped magnetic fluid sealing belt is formed between the salient pole 1 and the concave pole 3 by utilizing the principle of static pressure balance of fluid in a U-shaped pipe; the salient pole 1 is fixedly installed in the shell 8 through a support ring 9; the permanent magnet 4 and the concave pole 3 are connected into a whole and fixed on the rotating ring 5, the rotating ring 5 is fixedly arranged on the shaft 7, the shaft 7 rotates to drive the concave pole 3 and the permanent magnet 4 to synchronously rotate, and the concave pole 3 in a rotating state drives the magnetic fluid 2 to rotate so that the magnetic fluid 2 generates a radial outward centrifugal force; the magnetic fluid 2 is accumulated at the bottom of the U-shaped groove of the concave pole 3 under the combined action of centrifugal force and magnetic force; in order to increase the capacity of the recessed electrode 3 for driving the magnetic fluid 2 to rotate, the carrier liquid strips 6 are fixedly bonded in the recessed electrode 3; the outer end of the rotating ring 5 is provided with a separation plate 13, and the separation plate 13 is fixed on the shell 8; the U-shaped gap formed between the support ring 9, the rotating ring 5, the isolation plate 13 and the housing 8 is filled with magnetic grease 14.

In order to reduce the foreign matters from entering the sealing belt in consideration of the underwater application of the sealing, a mud throwing ring 10 is arranged on the shaft 7, the mud throwing ring 10 rotates synchronously with the shaft 7, and the foreign matters in the water are thrown out by utilizing centrifugal force.

According to the balance principle of the static pressure of fluid in the U-shaped pipe, when the sealing belt is in a static sealing state, the two magnetic fluids 2 keep balance under the action of the magnetic force right above; if no pressure difference exists at the two ends, the liquid level height difference h of the two magnetic fluids at the two ends is zero, if the pressure at one end is increased, the first magnetic fluid 2 is wholly deviated to one side with low pressure until new balance is achieved, at the moment, the first magnetic fluid 2 forms a liquid level height difference h1, because a closed space is formed between the two magnetic fluids 2, the pressure intensity of the closed space is increased due to space reduction, the pressure difference is further transmitted to the second magnetic fluid 2, at the moment, the second magnetic fluid 2 forms a liquid level height difference h2, and the magnetic fluids 2 in the two height difference zones jointly balance the external pressure difference under the action of magnetic force; when the sealing belt is in a dynamic sealing state, the magnetic fluid 2 in a rotating state is under the action of magnetic force and centrifugal force, the magnetic fluid and the centrifugal force are mutually superposed to jointly provide a radial force field to realize the static pressure balance of the U-shaped pipe, the higher the rotating speed is, the larger the centrifugal force is, the smaller the liquid level height difference can resist the extremely strong external pressure difference change, the excellent dynamic sealing effect is ensured, and the problem that the sealing failure is caused by the breakdown of the thinned thickness of the magnetic fluid 2 is avoided.

EXAMPLE III

As shown in fig. 8, a sealing method comprises a salient pole 1 and a concave pole 3 which are respectively fixed on a shell 8 and a shaft 7 which are coaxially arranged, wherein a V-shaped groove is arranged on the concave pole 3; the top of the salient pole 1 is arranged in the V-shaped groove of the concave pole 3, and a V-shaped gap is formed between the salient pole 1 and the concave pole 3; the magnetic fluid 2 is filled in the gap; a permanent magnet 4 is fixed on the outer side of the concave pole 3, the permanent magnet 4 is in an annular structure, is magnetized by radiation and is a monopole radiation ring, and the magnetic pole on the inner side of the permanent magnet 4 generates a magnetic force which is outward in the radial direction on the magnetic fluid 2; the magnetic fluid 2 overcomes the self gravity under the action of radial magnetic force, and a V-shaped magnetic fluid sealing belt is formed between the salient pole 1 and the concave pole 3 by utilizing the principle of static pressure balance of fluid in the U-shaped pipe; the salient pole 1 is fixedly installed in the shell 8 through a support ring 9; the permanent magnet 4 and the concave pole 3 are connected into a whole and fixed on the rotating ring 5, the rotating ring 5 is fixedly arranged on the shaft 7, the shaft 7 rotates to drive the concave pole 3 and the permanent magnet 4 to synchronously rotate, and the concave pole 3 in a rotating state drives the magnetic fluid 2 to rotate so that the magnetic fluid 2 generates a radial outward centrifugal force; the magnetic fluid 2 is accumulated at the bottom of the concave 3V-shaped groove under the combined action of centrifugal force and magnetic force; in order to increase the capacity of the recessed electrode 3 for driving the magnetic fluid 2 to rotate, the carrier liquid strips 6 are fixedly bonded in the recessed electrode 3; the outer end of the rotating ring 5 is provided with a separation plate 13, and the separation plate 13 is fixed on the shell 8; magnetic grease 14 is filled in a U-shaped gap formed among the support ring 9, the rotating ring 5, the isolating plate 13 and the shell 8; it should be noted that the cathode 3 is formed by combining semi-arc rings made of hard materials.

Example four

As shown in fig. 9, a sealing method comprises a salient pole 1 and a concave pole 3 which are respectively fixed on a shell 8 and a shaft 7 which are coaxially arranged, wherein a V-shaped groove is arranged on the concave pole 3; the top of the salient pole 1 is arranged in the V-shaped groove of the concave pole 3, and a V-shaped gap is formed between the salient pole 1 and the concave pole 3; the magnetic fluid 2 is filled in the gap; a permanent magnet 4 is fixed on the outer side of the concave pole 3, the permanent magnet 4 is in an annular structure, is magnetized by radiation and is a monopole radiation ring, and the magnetic pole on the inner side of the permanent magnet 4 generates a magnetic force which is outward in the radial direction on the magnetic fluid 2; the magnetic fluid 2 overcomes the self gravity under the action of radial magnetic force, and a V-shaped magnetic fluid sealing belt is formed between the salient pole 1 and the concave pole 3 by utilizing the principle of static pressure balance of fluid in the U-shaped pipe; the salient pole 1 is fixedly arranged on the shaft 7; the permanent magnet 4 and the concave pole 3 are connected into a whole and fixed on a positioning frame 12, the positioning frame 12 is fixedly arranged on a shell 8, the shell 8 rotates to drive the concave pole 3 and the permanent magnet 4 to synchronously rotate, and the concave pole 3 in a rotating state drives the magnetic fluid 2 to rotate, so that the magnetic fluid 2 generates a radial outward centrifugal force; the magnetic fluid 2 is accumulated at the bottom of the concave 3V-shaped groove under the combined action of centrifugal force and magnetic force; in order to increase the capacity of the recessed electrode 3 for driving the magnetic fluid 2 to rotate, the carrier liquid strips 6 are fixedly bonded in the recessed electrode 3; the outer end of the permanent magnet 4 is sequentially provided with a separation plate 13, a rotating ring 5 and a mud throwing ring 10 from inside to outside, the separation plate 13 and the mud throwing ring 10 are fixed on the shaft 7, and the rotating ring 5 is fixed in the shell 8; magnetic grease 14 is filled in a U-shaped gap formed among the permanent magnet 4, the rotating ring 5 and the isolation plate 13.

EXAMPLE five

As shown in fig. 10, a sealing method comprises a salient pole 1 and a concave pole 3 which are respectively fixed on a shell 8 and a shaft 7 which are coaxially arranged, wherein a U-shaped groove is arranged on the concave pole 3; the top of the salient pole 1 is arranged in the U-shaped groove of the concave pole 3, and a U-shaped gap is formed between the salient pole 1 and the concave pole 3; the magnetic fluid 2 is filled in the gap; a permanent magnet 4 is fixed on the outer side of the concave pole 3, the permanent magnet 4 is in an annular structure, is magnetized by radiation and is a monopole radiation ring, and the magnetic pole on the inner side of the permanent magnet 4 generates a magnetic force which is outward in the radial direction on the magnetic fluid 2; the magnetic fluid 2 overcomes the self gravity under the action of radial magnetic force, and a U-shaped magnetic fluid sealing belt is formed between the salient pole 1 and the concave pole 3 by utilizing the principle of static pressure balance of fluid in a U-shaped pipe; the salient pole 1 is fixedly installed in the shell 8 through a support ring 9; the permanent magnet 4 and the concave pole 3 are connected into a whole and fixed on the rotating ring 5, the rotating ring 5 is fixedly arranged on the shaft 7, the shaft 7 rotates to drive the concave pole 3 and the permanent magnet 4 to synchronously rotate, and the concave pole 3 in a rotating state drives the magnetic fluid 2 to rotate so that the magnetic fluid 2 generates a radial outward centrifugal force; the magnetic fluid 2 is accumulated at the bottom of the U-shaped groove of the concave pole 3 under the combined action of centrifugal force and magnetic force; in order to increase the capacity of the recessed electrode 3 for driving the magnetic fluid 2 to rotate, the carrier liquid strips 6 are fixedly bonded in the recessed electrode 3; in order to reduce the external impurities entering the sealing tape and the leakage of the magnetic fluid 2 during severe vibration, the edge part of the concave pole 3 is slightly contacted with the salient pole 1 to form a closed space, and the magnetic fluid 2 is sealed between the salient pole 1 and the concave pole 3; the outer end of the rotating ring 5 is provided with a separation plate 13, and the separation plate 13 is fixed on the shell 8; the U-shaped gap formed between the support ring 9, the rotating ring 5, the isolation plate 13 and the housing 8 is filled with magnetic grease 14.

It should be pointed out that, because the edge of the concave pole 3 slightly contacts the convex pole 1 to form a closed space, when the external pressure changes, the edge contact part can form a first protection, if the first protection fails, the magnetic fluid sealing tape implements a second protection, and the sealing effect is ensured under the dual action.

EXAMPLE six

As shown in fig. 11, a sealing method comprises a salient pole 1 and a concave pole 3 which are respectively fixed on a shell 8 and a shaft 7 which are coaxially arranged, wherein a V-shaped groove is arranged on the concave pole 3; the top of the salient pole 1 is arranged in the V-shaped groove of the concave pole 3, and a V-shaped gap is formed between the salient pole 1 and the concave pole 3; the magnetic fluid 2 is filled in the gap; a permanent magnet 4 is fixed on the outer side of the concave pole 3, the permanent magnet 4 is in an annular structure, is magnetized by radiation and is a monopole radiation ring, and the magnetic pole on the inner side of the permanent magnet 4 generates a magnetic force which is outward in the radial direction on the magnetic fluid 2; the magnetic fluid 2 overcomes the self gravity under the action of radial magnetic force, and a V-shaped magnetic fluid sealing belt is formed between the salient pole 1 and the concave pole 3 by utilizing the principle of static pressure balance of fluid in the U-shaped pipe; the salient pole 1 is fixedly installed in the shell 8 through a support ring 9; the permanent magnet 4 and the concave pole 3 are connected into a whole and fixed on the rotating ring 5, the rotating ring 5 is fixedly arranged on the shaft 7, the shaft 7 rotates to drive the concave pole 3 and the permanent magnet 4 to synchronously rotate, and the concave pole 3 in a rotating state drives the magnetic fluid 2 to rotate so that the magnetic fluid 2 generates a radial outward centrifugal force; the magnetic fluid 2 is accumulated at the bottom of the concave 3V-shaped groove under the combined action of centrifugal force and magnetic force; in order to increase the capacity of the recessed electrode 3 for driving the magnetic fluid 2 to rotate, the carrier liquid strips 6 are fixedly bonded in the recessed electrode 3; in order to ensure the relative position relationship between the salient pole 1 and the salient pole 3, a limiting part 11 is arranged between the salient pole 3 and the rotating ring 5, and the limiting part 11 is a rolling body and can be in the form of a ball or a roller pin.

EXAMPLE seven

As shown in fig. 12-13, a sealing method comprises a salient pole 1 and a concave pole 3, which are respectively fixed on a coaxially arranged shell 8 and a shaft 7, wherein a V-shaped groove is arranged on the concave pole 3; the top of the salient pole 1 is arranged in the V-shaped groove of the concave pole 3, and a V-shaped gap is formed between the salient pole 1 and the concave pole 3; the magnetic fluid 2 is filled in the gap; a permanent magnet 4 and an exciter 15 are fixed on the outer side of the concave pole 3, the permanent magnet 4 is in an annular structure, radiation magnetization is adopted, the permanent magnet is a single-pole radiation ring, and a magnetic pole on the inner side of the permanent magnet 4 generates outward radial magnetic force on the magnetic fluid 2; the magnetic fluid 2 overcomes the self gravity under the action of radial magnetic force provided by the permanent magnet, and a V-shaped magnetic fluid sealing tape is formed between the salient pole 1 and the concave pole 3 by utilizing the principle of static pressure balance of fluid in the U-shaped pipe; the concave pole 3, the permanent magnet 4 and the exciter 15 are connected into a whole and fixed on a positioning frame 12, and the positioning frame 12 is fixedly arranged on the shell 8 and is in a static state; the salient pole 1 is fixedly arranged on the shaft 7, and when the shaft 7 rotates, the salient pole 1 in a rotating state drives the magnetic fluid 2 to rotate, so that the magnetic fluid 2 generates a radial outward centrifugal force; the magnetic fluid 2 is accumulated at the bottom of the concave 3V-shaped groove under the combined action of centrifugal force and magnetic force; in order to increase the capacity of the salient pole 1 for driving the magnetic fluid 2 to rotate, the liquid carrying strip 6 is bonded on the salient pole 1; in order to ensure the relative position relationship between the salient pole 1 and the salient pole 3, a limiting part 11 is arranged between the positioning frame 12 and the salient pole 1, and the limiting part 11 is a rolling body and can be in the form of a ball or a roller pin; in order to reduce the foreign matters from entering the sealing belt in consideration of the underwater application of the sealing, a mud throwing ring 10 is arranged on the salient pole 1, the mud throwing ring 10 rotates along with the rotating shaft 7, and the foreign matters in the water are thrown out by using centrifugal force.

It should be pointed out that the said exciter 15 is a ring structure, adopt the integrated design, including the exciter 15-1, coil 15-2 and magnetic ring 15-3, the exciter 15-1 with coil 15-2 is distributed on the exciter ring 15-3, the said exciter 15 locates at the outside of the permanent magnet 4, the magnetic field that coil 15-2 is electrified and produced superposes with the magnetic field of the permanent magnet in the same direction, make the total intensity of magnetic field exerted on magnetic fluid increase with the increase of the electric current, and then make the sealing performance become controllable as required.

Example eight

As shown in fig. 14 to 15, a sealing assembly includes a salient pole 1 and a concave pole 3, which are respectively fixed on a coaxially arranged housing 8 and a shaft 7, wherein a V-shaped groove is formed on the concave pole 3; the top of the salient pole 1 is arranged in the V-shaped groove of the concave pole 3, and a V-shaped gap is formed between the salient pole 1 and the concave pole 3; the magnetic fluid 2 is filled in the gap; a permanent magnet 4 and an exciter 15 are fixed on the outer side of the concave pole 3, the permanent magnet 4 is in an annular structure, radiation magnetization is adopted, the permanent magnet is a single-pole radiation ring, and a magnetic pole on the inner side of the permanent magnet 4 generates outward radial magnetic force on the magnetic fluid 2; the magnetic fluid 2 overcomes the self gravity under the action of radial magnetic force provided by the permanent magnet, and a V-shaped magnetic fluid sealing tape is formed between the salient pole 1 and the concave pole 3 by utilizing the principle of static pressure balance of fluid in the U-shaped pipe; the concave pole 3, the permanent magnet 4 and the exciter 15 are connected into a whole and fixed on a positioning frame 12, and the positioning frame 12 is fixedly arranged on the shell 8 and is in a static state; the salient pole 1 is fixedly arranged on the shaft 7, and when the shaft 7 rotates, the salient pole 1 in a rotating state drives the magnetic fluid 2 to rotate, so that the magnetic fluid 2 generates a radial outward centrifugal force; the magnetic fluid 2 is accumulated at the bottom of the concave 3V-shaped groove under the combined action of centrifugal force and magnetic force; in order to increase the capacity of the salient pole 1 for driving the magnetic fluid 2 to rotate, the liquid carrying strip 6 is bonded on the salient pole 1; in order to ensure the relative position relationship between the salient pole 1 and the salient pole 3, a limiting part 11 is arranged between the positioning frame 12 and the salient pole 1, and the limiting part 11 is a rolling body and can be in the form of a ball or a roller pin; in order to reduce the foreign matters from entering the sealing belt in consideration of the underwater application of the sealing, a mud throwing ring 10 is arranged on the salient pole 1, the mud throwing ring 10 rotates along with the rotating shaft 7, and the foreign matters in the water are thrown out by using centrifugal force.

It should be pointed out that the said exciter 15 is a ring structure, is made up of the exciter unit, the said exciter unit includes the exciter pole 15-1, coil 15-2 and excitation tile 15-4, the exciter pole 15-1 wrapped by coil 15-2 is fixed on exciter tile 15-4, the said exciter 15 is placed outside the said permanent magnet 4, the magnetic field that the coil 15-2 is electrified and produced is superposed with the magnetic field of the permanent magnet in the same direction, make the total intensity of magnetic field exerted on magnetic fluid increase with the increase of the electric current, and then make the sealing performance become controllable according to the need; in order to increase the uniformity of the distribution of the magnetic field, the excitation units of each group are arranged in a staggered mode.

Example nine

As shown in fig. 16, a sealing method comprises a salient pole 1 and a concave pole 3 which are respectively fixed on a shell 8 and a shaft 7 which are coaxially arranged, wherein a U-shaped groove is arranged on the concave pole 3; the top of the salient pole 1 is arranged in the U-shaped groove of the concave pole 3, and a U-shaped gap is formed between the salient pole 1 and the concave pole 3; the magnetic fluid 2 is filled in the gap; a permanent magnet 4 is fixed on the outer side of the concave pole 3, the permanent magnet 4 is of an annular structure, a plurality of radial magnetized fan-shaped magnetic sheets 4-1 are combined, and in order to increase the distribution uniformity of a magnetic field, all groups of magnetic sheets 4-1 can be arranged in a staggered mode; the magnetic pole at the inner side of the permanent magnet 4 generates a magnetic force which is outward in the radial direction to the magnetic fluid 2; the magnetic fluid 2 overcomes the self gravity under the action of radial magnetic force, and a U-shaped magnetic fluid sealing belt is formed between the salient pole 1 and the concave pole 3 by utilizing the principle of static pressure balance in a fluid U-shaped pipe; the salient pole 1 is fixedly installed in the shell 8 through a support ring 9; the concave pole 3 is fixedly arranged on a shaft 7 through a rotating ring 5; the permanent magnet 4 is fixed in the shell 8 and is positioned above the outer side of the concave pole 3, and a gap is formed between the permanent magnet and the concave pole 3; the shaft 7 rotates to drive the concave pole 3 to rotate, and the concave pole 3 in a rotating state drives the magnetic fluid 2 to rotate, so that the magnetic fluid 2 generates a radial outward centrifugal force; the magnetic fluid 2 is accumulated at the bottom of the U-shaped groove of the concave pole 3 under the combined action of centrifugal force and magnetic force; in order to increase the capacity of the recessed electrode 3 for driving the magnetic fluid 2 to rotate, the carrier liquid strips 6 are fixedly bonded in the recessed electrode 3; the outer end of the rotating ring 5 is provided with a separation plate 13, and the separation plate 13 is fixed on the shell 8; magnetic grease 14 is filled in the U-shaped gap formed among the support ring 9, the rotating ring 5, the isolation plate 13 and the permanent magnet 4.

It should be pointed out that, at this time, the inner side and the outer side of the concave pole 3 both form a "U" shaped sealing band, when the concave pole 3 rotates, the inner and outer sealing bands resist external pressure difference under the same direction superposition of centrifugal force and magnetic force, and sealing performance is dually ensured; the rotating ring 5 is preferably made of a magnetic conductive material so as to reduce magnetic leakage and indirectly improve the magnetic force of the permanent magnet 4 on the magnetic fluid 2; the magnetic grease 14 can be replaced with the magnetic fluid 2, regardless of cost.

Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that changes, modifications, substitutions and alterations can be made in these embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the appended claims and their equivalents.

Claims

1. A method of sealing, characterized by: comprises salient poles and concave poles which are respectively fixed on a pair of coaxial rotatable parts; the concave pole is of an annular structure, the outer side of the concave pole is provided with a permanent magnet, and the inner side of the concave pole is provided with a U-shaped or V-shaped groove; the tops of the salient poles are arranged in the grooves, and U-shaped or V-shaped gaps are formed between the salient poles and the grooves; magnetic fluid is filled in the gap; the magnetic fluid is accumulated at the bottom of the groove under the action of a magnetic field provided by the magnetic poles at the inner side of the permanent magnet, and a U-shaped or V-shaped sealing strip is formed between the salient pole and the concave pole by utilizing the principle of static pressure balance of the fluid in the U-shaped pipe; the concave pole or the convex pole in the rotating state drives the magnetic fluid to rotate, so that the magnetic fluid generates centrifugal force, the static pressure balance of the magnetic fluid is realized under the equidirectional superposition effect of the centrifugal force and the magnetic force, the external pressure difference is resisted, and the faster the rotating speed is, the stronger the resisting capability is.

2. A method of sealing as claimed in claim 1, wherein: and a liquid carrying bar for increasing the contact area with the magnetic fluid is arranged in the gap and is fixed on the rotating part.

3. A sealing method according to claim 1 or 2, characterized in that: the permanent magnet is in an annular structure, adopts radiation magnetization and is a monopole radiation ring.

4. A method of sealing as claimed in claim 3, wherein: the permanent magnet and the concave pole are connected into a whole and fixed on the rotating part, and the salient pole is fixed on the static part.

5. A method of sealing as claimed in claim 4, wherein: the outer end of the rotating ring is provided with a separation plate, and the separation plate is fixed on the static part.

6. A method of sealing as claimed in claim 5, wherein: and a mud throwing ring is arranged at the outer end of the isolation plate and fixed on the rotating component.

7. A method of sealing as claimed in claim 3, wherein: the edge of the concave pole is in contact with the salient pole to form a closed space, and the magnetic fluid is limited in the closed space of a U shape or a V shape formed between the salient pole and the concave pole.

8. A method of sealing as claimed in claim 2, wherein: the permanent magnet and the concave pole are connected into a whole and fixed on the static part; the salient poles are fixed on the rotating component.

9. A method of sealing as claimed in claim 1, wherein: an exciter body wound with a coil is arranged on the outer side of the permanent magnet, and generates a magnetic field after the coil is electrified; the exciter body is fixed to the stationary member.

10. A method of sealing as claimed in claim 9, wherein: the excitation body comprises excitation columns and excitation rings, and the excitation columns wound with coils are uniformly distributed on the excitation rings.