CN117722502A - Magnetic fluid floating dynamic sealing device - Google Patents
Magnetic fluid floating dynamic sealing device Download PDFInfo
- Publication number
- CN117722502A CN117722502A CN202311680031.1A CN202311680031A CN117722502A CN 117722502 A CN117722502 A CN 117722502A CN 202311680031 A CN202311680031 A CN 202311680031A CN 117722502 A CN117722502 A CN 117722502A
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- magnetic fluid
- thrust disc
- disc
- dynamic seal
- sealing
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- 239000011553 magnetic fluid Substances 0.000 title claims abstract description 62
- 238000007789 sealing Methods 0.000 title claims abstract description 58
- 238000007667 floating Methods 0.000 title claims abstract description 22
- 230000003068 static effect Effects 0.000 claims abstract description 15
- 230000006835 compression Effects 0.000 claims description 14
- 238000007906 compression Methods 0.000 claims description 14
- 239000004020 conductor Substances 0.000 claims description 4
- 238000001816 cooling Methods 0.000 claims description 4
- 239000000110 cooling liquid Substances 0.000 claims description 3
- 239000000463 material Substances 0.000 claims 1
- 239000007788 liquid Substances 0.000 abstract description 17
- 230000001105 regulatory effect Effects 0.000 abstract description 3
- 230000009471 action Effects 0.000 description 3
- 230000001276 controlling effect Effects 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 230000033001 locomotion Effects 0.000 description 2
- 238000000034 method Methods 0.000 description 2
- 230000008569 process Effects 0.000 description 2
- 239000000725 suspension Substances 0.000 description 2
- 238000005299 abrasion Methods 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 230000005540 biological transmission Effects 0.000 description 1
- 238000004891 communication Methods 0.000 description 1
- 238000005336 cracking Methods 0.000 description 1
- 230000007123 defense Effects 0.000 description 1
- 239000013013 elastic material Substances 0.000 description 1
- 238000005265 energy consumption Methods 0.000 description 1
- 230000005484 gravity Effects 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 239000003208 petroleum Substances 0.000 description 1
- -1 polytetrafluoroethylene Polymers 0.000 description 1
- 229920001343 polytetrafluoroethylene Polymers 0.000 description 1
- 239000004810 polytetrafluoroethylene Substances 0.000 description 1
- 230000002035 prolonged effect Effects 0.000 description 1
- 238000005096 rolling process Methods 0.000 description 1
- 239000004065 semiconductor Substances 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
Landscapes
- Sealing Using Fluids, Sealing Without Contact, And Removal Of Oil (AREA)
Abstract
The invention discloses a magnetic fluid floating dynamic sealing device, which relates to the technical field of sealing, and comprises a thrust disc, a static sealing connecting piece, a dynamic sealing piece and a control piece, wherein the dynamic sealing piece is used for dynamic sealing between the thrust disc and a dynamic sealing shell; the distance between the first end of the pole tooth of the dynamic seal piece and the first side surface of the thrust disc is regulated and controlled by the control piece, on one hand, the thrust disc can be always kept parallel to the end surface of the pole tooth, so that the gap between the thrust disc and the end surface of the pole tooth can be always kept at 0.1mm or less, and the stability of the magnetic fluid liquid film seal is ensured; on the other hand, the size of the gap between the first end of the control pole tooth and the first side surface of the thrust disc can be adjusted according to the rotating speed of the rotating shaft.
Description
Technical Field
The invention relates to the technical field of sealing, in particular to a magnetic fluid floating dynamic sealing device.
Background
The magnetic fluid dynamic sealing device utilizes a magnetic field to restrict magnetic fluid in gaps between joint surfaces of relative motion, achieves the aim of preventing leakage of sealing media, and is widely applied to the fields of semiconductors, aerospace, national defense, chemical industry, petroleum, instruments, meters and the like.
In order to ensure that the magnetic fluid is relatively stable within the seal gap, the magnetic field strength within the seal gap is required to be sufficiently high. Therefore, the gap between the joint surfaces of the relative movement must be small. At present, a rotating shaft with low surface linear speed and stable operation generally adopts a high-precision rolling bearing to ensure a tiny gap between the rotating shaft and a sealing shell. However, in high speed heavy duty rotating machinery, the shaft experiences radial runout under asymmetric, non-steady loading. In order to avoid the collision and abrasion between the sealing interface of the rotating shaft and the shell, the sealing gap needs to be increased, so that the sealing gap is larger than the radial deflection amount of the rotating shaft. Under the conditions of high speed and large gap, the stability of the magnetic fluid is greatly reduced, and the bearing capacity is difficult to ensure. In addition, the common multi-stage magnetic fluid sealing device relies on the gradual depressurization or pressurization of the magnetic fluid liquid film of each stage to improve the overall sealing capability, and each magnetic fluid liquid film of each stage only bears smaller pressure. The process of realizing balanced load sharing of the magnetic fluid at each level is based on continuous rupture and self-repairing of the magnetic fluid liquid film at each level and proper leakage of the sealing medium from the high-pressure end to the low-pressure end. Under the conditions of high speed and large gap, the stability of the magnetic fluid is reduced, and in the process of cracking the magnetic fluid liquid film, a large amount of magnetic fluid is transferred from a high pressure side to a low pressure side in a large amount under the drive of a sealing medium, so that the magnetic fluid filled in the sealing gap is obviously reduced, the magnetic fluid liquid film cannot realize self-repairing, the sealing capability is obviously reduced, and the long-service-life working requirement cannot be met.
Disclosure of Invention
The invention aims to solve the problems and designs a magnetic fluid floating dynamic sealing device.
The invention realizes the above purpose through the following technical scheme:
the magnetic fluid floating dynamic seal device is used for dynamic seal between a rotating shaft and a dynamic seal shell and comprises:
a thrust plate;
a static seal connection; the static seal connecting piece is used for static seal fixed connection between the thrust disc and the rotating shaft;
at least one set of dynamic seals; the dynamic sealing piece is used for dynamic sealing between the thrust disc and the dynamic sealing shell, and is arranged on the first side surface of the thrust disc; each group of dynamic sealing elements comprises an annular pole shoe and magnetic fluid, the first end of the pole shoe is fixedly arranged on the sealing shell, the second end of the pole shoe is provided with a plurality of annular pole teeth, the magnetic fluid is positioned between the first end of the pole teeth and the first side surface of the thrust disc, and the pole shoe has magnetic force;
a control member; the control member is used for adjusting and controlling the distance between the first end of the pole tooth of the dynamic sealing member and the first side surface of the thrust disc.
The invention has the beneficial effects that: the distance between the first end of the pole tooth of the dynamic seal piece and the first side surface of the thrust disc is regulated and controlled by the control piece, on one hand, the thrust disc can be always kept parallel to the end surface of the pole tooth, so that the gap between the thrust disc and the end surface of the pole tooth can be always kept at 0.1mm or less, and the stability of the magnetic fluid liquid film seal is ensured; on the other hand, the size of the gap between the first end of the control pole tooth and the first side surface of the thrust disc can be adjusted according to the rotating speed of the rotating shaft.
Drawings
FIG. 1 is a schematic diagram of a magnetic fluid floating dynamic seal arrangement of the present invention;
FIG. 2 is a schematic diagram of the dynamic seal in the magnetic fluid floating dynamic seal device of the present invention;
FIG. 3 is a schematic view of the structure of the teeth in the magnetic fluid floating dynamic seal device of the present invention;
FIG. 4 is a schematic view of the structure of an elastic disc in the magnetic fluid floating dynamic seal device of the present invention;
wherein corresponding reference numerals are as follows:
the device comprises a thrust disc, a 2-elastic disc, a 3-rotating shaft, a 4-pole shoe, 5-magnetic fluid, 6-pole teeth, 7-pressure relief holes, 8-permanent magnet rings, 9-electromagnets, a 10-distance sensor, 11-cooling liquid, 12-first compression rings, 13-second compression rings, 14-first screws, 15-second screws, 16-anti-collision blocks, 17-anti-collision grooves and 18-dynamic seal shells.
Detailed Description
In order to make the objects, technical solutions and advantages of the embodiments of the present invention more clear, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. It will be apparent that the described embodiments are some, but not all, embodiments of the invention. The components of the embodiments of the present invention generally described and illustrated in the figures herein may be arranged and designed in a wide variety of different configurations.
Thus, the following detailed description of the embodiments of the invention, as presented in the figures, is not intended to limit the scope of the invention, as claimed, but is merely representative of selected embodiments of the invention. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.
It should be noted that: like reference numerals and letters denote like items in the following figures, and thus once an item is defined in one figure, no further definition or explanation thereof is necessary in the following figures.
In the description of the present invention, it should be understood that the directions or positional relationships indicated by the terms "upper", "lower", "inner", "outer", "left", "right", etc. are based on the directions or positional relationships shown in the drawings, or the directions or positional relationships conventionally put in place when the inventive product is used, or the directions or positional relationships conventionally understood by those skilled in the art are merely for convenience of describing the present invention and simplifying the description, and do not indicate or imply that the apparatus or elements referred to must have a specific direction, be configured and operated in a specific direction, and therefore should not be construed as limiting the present invention.
Furthermore, the terms "first," "second," and the like, are used merely to distinguish between descriptions and should not be construed as indicating or implying relative importance.
In the description of the present invention, it should also be noted that, unless explicitly specified and limited otherwise, terms such as "disposed," "connected," and the like are to be construed broadly, and for example, "connected" may be either fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; can be directly connected or indirectly connected through an intermediate medium, and can be communication between two elements. The specific meaning of the above terms in the present invention can be understood by those of ordinary skill in the art according to the specific circumstances.
The following describes specific embodiments of the present invention in detail with reference to the drawings.
As shown in fig. 1, 2, 3 and 4, the magnetic fluid 5 floating dynamic seal device is used for dynamic sealing between the rotating shaft 3 and the dynamic seal housing 18, and comprises:
a thrust disc 1;
a static seal connection; the static seal connecting piece is used for static seal fixed connection between the thrust disc 1 and the rotating shaft 3;
at least one set of dynamic seals; the dynamic seal is used for dynamic seal between the thrust disc 1 and the dynamic seal shell 18, and is arranged on the first side surface of the thrust disc 1; each group of dynamic sealing elements comprises an annular pole shoe 4 and magnetic fluid 5, the first end of the pole shoe 4 is fixedly arranged on the sealing shell, the second end of the pole shoe 4 is provided with a plurality of annular pole teeth 6, the magnetic fluid 5 is positioned between the first end of the pole teeth 6 and the first side surface of the thrust disc 1, and the pole shoe 4 has magnetic force;
a control member; the control piece is used for adjusting and controlling the distance between the first end of the pole tooth 6 of the dynamic seal piece and the first side surface of the thrust disc 1, the dynamic seal shell 18 is made of a non-magnetic conductive material, and the dynamic seal shell 18 is fixedly arranged on a cavity structure to be sealed through static seal measures.
The second ends of the pole teeth 6 are provided with pressure relief holes 7.
The pole shoe 4 is fixed with a permanent magnet ring 8, and the pole shoe 4 is made of magnetic conductive materials.
The control member comprises an electromagnet 9 and the thrust disc 1 is made of a magnetically conductive material.
The control piece also comprises a distance sensor 10, a microprocessor and a driver, wherein the distance sensor 10 is used for collecting the distance between the thrust disc 1 and the distance sensor 10, the data signal output end of the distance sensor 10 is connected with the data signal input end of the microprocessor, the control signal output end of the microprocessor is connected with the control signal input end of the driver, and the output end of the driver is connected with the control signal input end of the electromagnet 9.
The static seal connecting piece comprises an elastic disc 2, a first compression ring 12, a second compression ring 13, a group of first screws 14 and a group of second screws 15, wherein a connecting ring is arranged on the outer side wall of a rotating shaft 3, a group of first threaded connecting holes are formed in the connecting ring, the first compression ring 12 and the inner side of the elastic disc 2, one first screw 14 is in threaded connection with the first compression ring 12, the elastic disc 2 and one first threaded connecting hole of the connecting ring respectively, a group of second threaded connecting holes are formed in the outer sides of the thrust disc 1, the second compression ring 13 and the elastic disc 2, and one second screw 15 is in threaded connection with one second threaded connecting hole of the second compression ring 13, the elastic disc 2 and the thrust disc 1 respectively.
The magnetic fluid 5 floating dynamic seal device further comprises at least three anti-collision blocks 16, an anti-collision groove 17 is formed in the inner side of each anti-collision block 16, an anti-collision ring is arranged on the outer side wall of the thrust disc 1, the anti-collision rings are located in the anti-collision grooves 17, the anti-collision blocks 16 are arranged on the periphery of the thrust disc 1 in an annular array with the central axis of the rotating shaft 3 as the center of a circle, the distance between each anti-collision block 16 and each anti-collision ring is larger than zero, and a self-lubricating layer such as polytetrafluoroethylene is plated in each anti-collision groove 17.
An annular cooling chamber is provided in the dynamic seal housing 18, and the cooling chamber is filled with the cooling liquid 11.
The working principle of the magnetic fluid 5 floating dynamic sealing device is as follows:
the pole shoe 4 forms a static sealing loop by connecting the dynamic sealing shell 18 with the cavity structure to be sealed.
The magnetic fluid 5 is filled in the gap between the end face pole teeth 6 of the pole shoe 4 and the thrust disc 1, and under the constraint of the magnetic field generated by the permanent magnet ring 8, the magnetic fluid 5 forms an end face rotary sealing loop between the pole shoe 4 and the thrust disc 1.
The elastic disc 2 is a thin-wall structure made of elastic material, and has high circumferential rigidity and small axial rigidity. The rotating shaft 3 can drive the thrust disc 1 to rotate through the elastic disc 2, and the elastic disc 2 allows the thrust disc 1 to freely move in a small axial range relative to the rotating shaft 3 or the sealing cavity.
The permanent magnet ring 8 simultaneously generates upward magnetic attraction force to the thrust disc 1 through the pole shoe 4, the electromagnet 9 generates downward magnetic attraction force to the thrust disc 1, and the thrust disc 1 is in a magnetic suspension state under the self gravity, the magnetic attraction force of the pole shoe 4 and the magnetic attraction force of the electromagnet 9.
The distance sensor 10 detects the axial position of the thrust disc 1 in real time, and the position of the thrust disc 1 in a balanced state can be changed by adjusting the magnetic attraction force of the current-adjusting electromagnet 9 which is introduced into the electromagnet 9, so that the sealing gap between the end face pole teeth 6 of the pole shoes 4 and the thrust disc 1 is adjusted.
The end face pole teeth 6 of the pole shoe 4 are provided with a group of radial pressure relief holes 7, and the pressure difference at two sides of each stage of pole teeth 6 is maintained by designing the diameter of the pressure relief holes 7 on the premise of ensuring the leakage quantity requirement. When the pressure at the two sides of the pole teeth 6 is higher than the set bearing pressure of the magnetic fluid 5 liquid film, the sealing medium flows through the pressure relief hole 7 in an accelerating way, the high-pressure side pressure is rapidly reduced, and the low-pressure side pressure is rapidly increased until the pressure difference at the two sides of the pole teeth 6 is returned to or lower than the set pressure.
The elastic disc 2 is connected with the rotating shaft 3 and the thrust disc 1, so that static seal between the rotating shaft 3 and the thrust disc 1 is realized, torque transmission between the rotating shaft 3 and the thrust disc 1 is ensured, and radial deflection generated by the rotating shaft 3 driving the thrust disc 1 does not influence a sealing gap between the thrust disc 1 and the pole shoe 4.
The permanent magnet ring 8 is matched with the pole shoe 4, on one hand, the magnetic fluid 5 is restrained in a gap between the pole shoe 4 and the thrust disc 1 to form dynamic seal, and on the other hand, the permanent magnet ring is matched with the electromagnet 9 and the distance sensor 10 to enable the thrust disc 1 to be in a magnetic suspension state.
According to the data fed back by the distance sensor 10, the magnetic attraction force of the electromagnet 9 can be adjusted by adjusting the current fed into the electromagnet 9, on one hand, the thrust disc 1 can be always parallel to the end face of the pole tooth 6 of the pole shoe 4, so that the gap between the thrust disc 1 and the end face of the pole tooth 6 of the pole shoe 4 can be kept at 0.1mm or smaller, and the stability of the liquid film sealing of the magnetic fluid 5 is ensured. On the other hand, the magnetic attraction force of the electromagnet 9 can be adjusted according to the rotating speed of the rotating shaft 3 so as to control the size of the sealing gap.
When the rotating speed of the rotating shaft 3 is low, the stability of the liquid film of the magnetic fluid 5 is relatively high, the current fed into the electromagnet 9 can be increased, the magnetic attraction force of the electromagnet 9 is increased, the thrust disc 1 is far away from the pole shoe 4 under the action of the magnetic attraction force, so that the sealing gap is properly increased, at the moment, the magnetic field intensity in the sealing gap is reduced, and the viscosity of the magnetic fluid 5 is reduced; at the same time the shear rate inside the magnetic fluid 5 is reduced and the internal friction is reduced. Therefore, when the rotating shaft 3 works at a low speed, the friction moment and heat of the magnetic fluid 5 can be reduced on the premise of ensuring the sealing capability, and the energy consumption is reduced.
When the rotating speed of the rotating shaft 3 is higher, the stability of the liquid film of the magnetic fluid 5 is relatively poor, the current fed into the electromagnet 9 can be reduced, the magnetic attraction force of the electromagnet 9 is reduced, the thrust disc 1 is close to the pole shoe 4 under the action of the magnetic attraction force of the permanent magnet ring 8, so that the sealing gap is reduced, at the moment, the flow stability of the liquid film of the magnetic fluid 5 in the sealing gap is enhanced, meanwhile, the magnetic field intensity in the gap is enhanced, the viscosity of the magnetic fluid 5 is increased, and the sealing capability of the liquid film of the magnetic fluid 5 is greatly increased. Therefore, sufficient sealing capability can be ensured at the time of high-speed operation of the rotary shaft 3.
The end face pole teeth 6 of the pole shoe 4 are provided with a group of radial pressure relief holes 7, when the pressure on two sides of the pole teeth 6 exceeds the set bearing pressure of the magnetic fluid 5 liquid film, the pressure on the two sides of the pole teeth 6 is regulated through the pressure relief holes 7, so that the magnetic fluid 5 liquid film is prevented from being broken under the action of an excessive pressure difference, the magnetic fluid 5 is prevented from being blown away by a sealing medium moving at a high speed when the liquid film is broken, the integrity of the magnetic fluid 5 liquid film can be protected, and the sealing service life of the magnetic fluid 5 is greatly prolonged.
The technical scheme of the invention is not limited to the specific embodiment, and all technical modifications made according to the technical scheme of the invention fall within the protection scope of the invention.
Claims (9)
1. The magnetic fluid floating dynamic seal device is used for dynamic seal between a rotating shaft and a dynamic seal shell and is characterized by comprising:
a thrust plate;
a static seal connection; the static seal connecting piece is used for static seal fixed connection between the thrust disc and the rotating shaft;
at least one set of dynamic seals; the dynamic sealing piece is used for dynamic sealing between the thrust disc and the dynamic sealing shell, and is arranged on the first side surface of the thrust disc; each group of dynamic sealing elements comprises an annular pole shoe and magnetic fluid, the first end of the pole shoe is fixedly arranged on the sealing shell, the second end of the pole shoe is provided with a plurality of annular pole teeth, the magnetic fluid is positioned between the first end of the pole teeth and the first side surface of the thrust disc, and the pole shoe has magnetic force;
a control member; the control member is used for adjusting and controlling the distance between the first end of the pole tooth of the dynamic sealing member and the first side surface of the thrust disc.
2. The magnetic fluid floating dynamic seal apparatus of claim 1 wherein the second ends of the pole teeth are each provided with a pressure relief aperture.
3. The magnetic fluid floating dynamic seal apparatus according to claim 1 or 2, wherein the pole shoe is fixed with a permanent magnet ring, and is made of a magnetically conductive material.
4. The magnetic fluid floating dynamic seal apparatus of claim 1 wherein the control member comprises an electromagnet and the thrust disc is made of magnetically permeable material.
5. The floating dynamic seal device of claim 4, wherein the control member further comprises a distance sensor, a microprocessor and a driver, wherein the distance sensor is used for collecting the distance between the thrust disc and the distance sensor, a data signal output end of the distance sensor is connected with a data signal input end of the microprocessor, a control signal output end of the microprocessor is connected with a control signal input end of the driver, and an output end of the driver is connected with a control signal input end of the electromagnet.
6. The magnetic fluid floating dynamic seal device according to claim 1, wherein the static seal connecting piece comprises an elastic disc, a first compression ring, a second compression ring, a group of first screws and a group of second screws, the outer side wall of the rotating shaft is provided with a connecting ring, the first compression ring and the inner side of the elastic disc are respectively provided with a group of first threaded connecting holes, one first screw is respectively in threaded connection with one first threaded connecting hole of the first compression ring, the elastic disc and the connecting ring, the outer sides of the thrust disc, the second compression ring and the elastic disc are respectively provided with a group of second threaded connecting holes, and one second screw is respectively in threaded connection with one second threaded connecting hole of the second compression ring, the elastic disc and the thrust disc.
7. The magnetic fluid floating dynamic seal device according to claim 1, further comprising at least three anti-collision blocks, wherein an anti-collision groove is formed in the inner side of each anti-collision block, an anti-collision ring is arranged on the outer side wall of the thrust disc, the anti-collision ring is located in the anti-collision groove, and the anti-collision blocks are annularly arranged on the periphery of the thrust disc by taking the central axis of the rotating shaft as a circle center.
8. The magnetic fluid floating dynamic seal apparatus of claim 7 wherein a self-lubricating layer is plated in the anti-collision groove.
9. The magnetic fluid floating dynamic seal apparatus of claim 1, wherein an annular cooling chamber is provided in the dynamic seal housing, and the cooling chamber is filled with a cooling liquid.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202311680031.1A CN117722502A (en) | 2023-12-08 | 2023-12-08 | Magnetic fluid floating dynamic sealing device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202311680031.1A CN117722502A (en) | 2023-12-08 | 2023-12-08 | Magnetic fluid floating dynamic sealing device |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN117722502A true CN117722502A (en) | 2024-03-19 |
Family
ID=90200833
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202311680031.1A Pending CN117722502A (en) | 2023-12-08 | 2023-12-08 | Magnetic fluid floating dynamic sealing device |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN117722502A (en) |
-
2023
- 2023-12-08 CN CN202311680031.1A patent/CN117722502A/en active Pending
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