CN200989445Y - Magnetic fluid centring seal bearing - Google Patents
Magnetic fluid centring seal bearing Download PDFInfo
- Publication number
- CN200989445Y CN200989445Y CN 200620116050 CN200620116050U CN200989445Y CN 200989445 Y CN200989445 Y CN 200989445Y CN 200620116050 CN200620116050 CN 200620116050 CN 200620116050 U CN200620116050 U CN 200620116050U CN 200989445 Y CN200989445 Y CN 200989445Y
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- magnetic fluid
- magnetic
- stuffing box
- centering
- permanent magnet
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- Sealing Using Fluids, Sealing Without Contact, And Removal Of Oil (AREA)
- Magnetic Bearings And Hydrostatic Bearings (AREA)
Abstract
A magnetic fluid centering sealed bearing is a dynamic sealing device for rotating (or translating) a machine. Making use of the law of ''automatic centering'' of the magnetic fluid, the utility model changes the external magnetic field (permanent magnet) of the traditional magnetic fluid sealed bearing into internal magnetic field, cancels the guide magnetic pole piece of the traditional sealed bearing, transforms ''liquid O-ring'' of the magnetic fluid into ''liquid cylindrical piston'' and solves the three big difficulties of the traditional magnetic fluid sealed bearing: 1. under the same sealing pressure condition, compared with that of the traditional magnetic fluid sealed bearing, the volume of the utility model reduces more than 60%; 2. making use of the law of ''automatic centering'', the demand of machining accuracy towards sealed bearing obviously decreases; 3. the dried-up time of the magnetic fluid is greatly prolonged for the magnetic fluid works in a basically closed environment.
Description
Technical field
The utility model belongs to the mechanical engineering technical field of sealing technology, is specially adapted to the sealing of running shaft.
Background technique
Magnetic fluid (claiming magnetic liquid again) is a kind of novel liquid magnetic material, and it has the magnetic of magnetic material and the flowability of liquid concurrently, can be attracted by magnetic field.Obtained using widely in various fields such as machinery, electronics, aviation, medicine.
At present, the device for sealing magnetic fluid that utilizes the magnetic current physical efficiency to be designed by the characteristic of magnetic field suction, its basic principle as shown in Figure 1: it is made up of permanent magnet 1, magnetic conductive pole piece 2, running shaft 3 and magnetic fluid 4.According to running shaft is that magnetic conductivity is (as Fig. 1-a) and non-magnetic (as Fig. 1-b), can be designed to two kinds of structures of a, b.These two kinds of structures can attract magnetic fluid and be fixed on around the running shaft, form " O " RunddichtringO of a kind of liquid, play sealing and lubricated effect.But the structure of this " liquid O type circle " is magnetic fluid 4 to be attracted to form around running shaft 3 by the magnetic force that magnetic conductive pole piece 2 provides by external permanent magnet 1.Because the magnetic field that permanent magnet provides need just can be transmitted to around the running shaft by magnetic conductive pole piece, magnetic force is attenuated, and the pressure that causes " liquid O type circle " can bear is generally all lower, and every grade of seal ring approximately can bear the pressure of 0.015～0.020MPa.If will improve voltage endurance capability, said structure repeatedly must be repeated, a plurality of magnetic conductive pole pieces promptly are set on bearing, its total voltage endurance capability is voltage endurance capability sums at different levels.When if the total voltage endurance capability of design is 0.20MPa, said structure just needs to repeat to cause the structure of bearing more complicated more than ten times, and volume is bigger.For reduced volume, 6672592 pairs of above-mentioned defectives of U.S. Pat have been carried out useful improvement, and a plurality of magnetic conductive pole pieces are integrated, and the voltage endurance capability of the stuffing box bearing of same volume is multiplied.Chinese patent ZL200320126699.3 also provides one " reducing the device for sealing magnetic fluid of radial space size ".The common feature of above-mentioned patent is: because the existence of magnetic conductive pole piece, make the structure after the above-mentioned improvement still very complicated, bulk is also still bigger.In addition, in this structure, magnetic fluid is to be in a kind of semi-open environment to work, and bearing causes seal failure because of the volatilization of magnetic fluid easily.
At above-mentioned shortcoming, it is little that the utility model will provide a kind of volume, simple in structure, and magnetic fluid is in the stuffing box bearing of working under the environment of base closed.
The utility model has this natural phenomenon of " self-alignment " function according to magnetic fluid and designs.
When we put into a small magnet in the beaker that fills magnetic fluid, we find that small magnet can the evenhanded middle that just in time swims in magnetic fluid; Even you shift small magnet onto beaker with a very big external force certain on one side, but external force is in case eliminate, small magnet just can float to the middle (see figure 2) of magnetic fluid immediately again.The reason that this self-alignment phenomenon produces is owing to have a fixing magnetic field, DISTRIBUTION OF MAGNETIC FIELD situation can be represented by the magnetic line of force among the figure (as Fig. 2-a) around permanent magnet.(as Fig. 2-b), under the effect in magnetic field, magnetic fluid has by the magnetic line of force and distributes and the trend of reorientating, and promptly having a magnetic force that attracts magnetic fluid, its size around magnet is by the density decision of the magnetic line of force when permanent magnet places magnetic fluid.Near more by permanent magnet, the magnetic line of force is close more, thereby magnetic force is also just big more.This caused magnetic fluid accumulate in tightly permanent magnet around, permanent magnet is positioned at automatically " the " center " position of magnetic fluid.
Summary of the invention
Technical problem to be solved in the utility model is: overcome magnet fluid sealing bearing structure complexity in the prior art, bulk is big, magnetic fluid is the deficiency of volatilization easily, a kind of stuffing box bearing by magnetic fluid centering is provided, make this stuffing box bearing under the constant situation of voltage endurance capability, volume can reduce more than 60%, and the requirement of machining accuracy is significantly reduced, and also can obviously improve working life.
The technical solution of the utility model is: utilize magnetic fluid to have the rule of " self-alignment ", external magnetic field in the conventional magnetic fluid stuffing box bearing (permanent magnet) is changed into built-in magnetic field with self-centering action, simplified design significantly so not only, and can become " liquid cylinder-piston " (see figure 3) to " the liquid O shape circle " of magnetic fluid, improved the voltage endurance capability of stuffing box bearing greatly.
The beneficial effects of the utility model are: after adopting built-in magnetic field, cancelled the magnetic conductive pole piece of conventional seals bearing, made the magnetic field in the new bearing directly pass to magnetic fluid by permanent magnet, the magnetic of permanent magnet is fully utilized.Permanent magnet is suspended in the cavity central authorities of shell under " self-alignment " effect of magnetic fluid, and forms " the liquid cylinder-piston " that can bear very big pressure with magnetic fluid, makes whole bearing have low surface friction drag and zero sealing function of revealing.Simultaneously, because magnetic fluid is in the cavity of basic sealing,, prolonged the working life of magnetic fluid effectively so the evaporation rate ratio is low under open environment.
Description of drawings
Fig. 1 magnet fluid sealing bearing schematic diagram;
Fig. 2 magnetic fluid " self-alignment " schematic representation;
Fig. 3 magnetic fluid centering stuffing box bearing schematic diagram;
The multi-stage sealed schematic diagram of Fig. 4 magnetic fluid centering stuffing box bearing.
Among Fig. 3,4: shell 1, permanent magnet 2, running shaft 3, magnetic fluid 4.
Embodiment
With accompanying drawing 3 is that the utility model is described in further detail for embodiment:
Magnetic fluid is felt relieved stuffing box bearing by shell 1, permanent magnet 2, and running shaft 3,4 four critical pieces of magnetic fluid constitute.Shell 1 is combined by housing and cap.The shape of housing and cap can be identical with size, also can be different.Can be radial symmetric or asymmetric two-part, also can be axial symmetry or asymmetric two-part.Its compound mode can adopt bolt connection, threaded cap to spin, also can adopt riveted joint, welding, adhesive bonds etc., can also directly be embedded in the bearing support of equipment.Housing shaft is provided with the circular hole of two symmetries to both sides, and its aperture is bigger slightly than the diameter of running shaft 3.Shell and running shaft adopt non-magnetic nonmagnetic substance to make, as stainless steel, copper, aluminium, engineering plastics, pottery etc.Permanent magnet 2 is designed to an annular, and the size of its axial thickness generally is 0.1-0.5 a times of magnet ring external diameter.The material of permanent magnet can be determined according to the voltage endurance capability of bearing.The magnetic intensity of permanent magnet is big more, and then the voltage endurance capability of bearing is also big more.Generally speaking, can select different magnetic materials such as neodymium iron boron, SmCo, aluminium nickel cobalt, ferrite for use.The N of permanent magnet, the S utmost point distribute (as shown in Figure 3) vertically.The kind of magnetic fluid 4 can be determined according to the ambient temperature of sealed medium and work.For the vacuum seal of ambient temperature more than 40 ℃, can select the BH-2 magnetic fluid of the low volatility of BJ University of Aeronautics ﹠ Astronautics's development for use.If sealed is gas and the normal temperature environment below 35 ℃, then can selects the universal BH-1 magnetic fluid of BJ University of Aeronautics ﹠ Astronautics's development for use, even can use the bigger keryl magnetic fluid of volatility.
The assembling of magnetic fluid centering stuffing box bearing: annular permanent magnet 2 is enclosed within the rotating shaft 3.Can be the drive fit that does not have relative movement between the two, also can be the loose fit that relative movement is arranged.When relative movement being arranged between the two, running shaft can also be done the linear axial motion.The gap of permanent magnet and outer casing inner wall is 0.1-0.5mm.Magnetic fluid is filled in the enclosure the space, constitutes " liquid cylinder-piston " with permanent magnet, and the environment on isolated bearing both sides plays the effect of sealing.
A plurality of annular permanent magnets are combined closely by the order of NS, SN, NS... vertically, can form magnet fluid sealing bearing with multi-stage sealed ability.Its voltage endurance capability of n level stuffing box bearing that is made of n annular permanent magnet is n times that single-stage seals.
Magnetic fluid centering stuffing box bearing also can be used as unsealed plain bearing and uses.If increase substantially the bearing capacity of stuffing box bearing, can also install plain ball bearing additional in bearing shell both sides.
Use-case one: process magnetic fluid centering stuffing box bearing by principle shown in Figure 3: shell sizes is φ 24 * 12.8mm, and material is a brass.Wall thickness 4mm, housing and cap are made up of axial asymmetric two-part, connect by non-magnetic conduction bolton.Enclosure axis is respectively stayed the φ 5.1mm through hole of a symmetry to both sides.Permanent magnet is a φ 15 * 3.8mm, and endoporus is the magnetic Nd-Fe-B ring of φ 5.0mm.Running shaft is the stainless steel round bar of φ 5.0 * 20.0mm.Running shaft directly inserts the magnet ring endoporus, and both drive fits do not have relative movement.The gap of permanent magnet and outer casing inner wall is 0.5mm, and fill with 0.35 gram BH-2 magnetic fluid in the space that permanent magnet and shell constitute.The static limit voltage endurance capability of this magnetic fluid centering stuffing box bearing is 0.04Mpa, is 2 times of conventional magnetic fluid stuffing box bearing single-stage voltage endurance capability.The conventional magnetic fluid stuffing box bearing of the equal voltage endurance capability of volume ratio has reduced about 60%.
Use-case two: process the magnetic fluid centering stuffing box bearing of three grades of sealings by Fig. 4, shell sizes is φ 26.5 * 15.0mm, and material is a brass.Wall thickness 5mm, housing and cap are made up of axial asymmetric two-part, spin by threaded cap.Enclosure axis is respectively stayed the φ 5.6mm through hole of a symmetry to both sides.Permanent magnet is three φ 10 * 1.5mm, and endoporus is the magnetic Nd-Fe-B ring of φ 5.0mm, presses NS, SN, the arrangement of NS order, and by running shaft they is closely linked together by force.Running shaft is the stainless steel round bar of two φ 5.0 * 15.0mm, is inserted in the diameter phi≤5.0mm of bore portion in the magnet ring, and the diameter of part is φ 5.5mm beyond the magnet ring endoporus, and both are screwed in together by the thread screw that is provided with on the running shaft.The gap of permanent magnet and outer casing inner wall is 0.25mm, and fill with 0.15 gram BH-2 magnetic fluid in the space that permanent magnet and shell constitute.The static limit voltage endurance capability of this magnetic fluid centering stuffing box bearing is 0.12Mpa, is 2 times of three grades of voltage endurance capabilities of conventional magnetic fluid stuffing box bearing.The conventional magnetic fluid stuffing box bearing of the equal voltage endurance capability of volume ratio is little more than 60%.
Claims (7)
1, magnetic fluid centering stuffing box bearing is made up of shell, permanent magnet, running shaft, four critical pieces of magnetic fluid, it is characterized in that: with the permanent magnet in the conventional magnetic fluid stuffing box bearing by external change into built-in.
2, magnetic fluid centering stuffing box bearing according to claim 1, it is characterized in that: described shell and running shaft adopt non-magnetic nonmagnetic substance manufacturing.
3, magnetic fluid centering stuffing box bearing according to claim 1, it is characterized in that: described shell is connected by bolt with cap by housing or threaded cap spins or rivet or weld or mode such as adhesive bonds is combined, and housing and cap also can directly be embedded in the bearing support of equipment.
4, magnetic fluid centering stuffing box bearing according to claim 1, it is characterized in that: described permanent magnet is designed to an annular, and the axial thickness of annular solid is generally 0.1-0.5 times of magnet ring external diameter.
5, magnetic fluid according to claim 1 centering stuffing box bearing, it is characterized in that: the gap between described permanent magnet and outer casing inner wall is 0.1-0.5mm, magnetic fluid is filled in the enclosure the space.
6, magnetic fluid centering stuffing box bearing according to claim 4, it is characterized in that: the order combination of pressing NS, SN, NS... by n annular permanent magnet vertically, can form the magnet fluid sealing bearing with n level sealability, its total voltage endurance capability is n a times of single-stage sealing.
7, magnetic fluid centering stuffing box bearing according to claim 1 is characterized in that: can install plain ball bearing additional in bearing shell both sides.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 200620116050 CN200989445Y (en) | 2006-05-25 | 2006-05-25 | Magnetic fluid centring seal bearing |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 200620116050 CN200989445Y (en) | 2006-05-25 | 2006-05-25 | Magnetic fluid centring seal bearing |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN200989445Y true CN200989445Y (en) | 2007-12-12 |
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Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN 200620116050 Expired - Fee Related CN200989445Y (en) | 2006-05-25 | 2006-05-25 | Magnetic fluid centring seal bearing |
Country Status (1)
| Country | Link |
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| CN (1) | CN200989445Y (en) |
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105508434A (en) * | 2016-02-17 | 2016-04-20 | 张广 | Self-aligning ball bearing with displacement compensation function and damping function |
| CN105508428A (en) * | 2016-02-17 | 2016-04-20 | 张广 | Cylindrical roller bearing with displacement compensation function and damping function |
| CN105508433A (en) * | 2016-02-17 | 2016-04-20 | 张广 | Double-row cylindrical roller bearing with angle compensation function and damping function |
| CN105526264A (en) * | 2016-02-17 | 2016-04-27 | 张广 | Self-aligning ball bearing with angle compensation function and damping function |
| CN105526263A (en) * | 2016-02-17 | 2016-04-27 | 张广 | Double-row cylindrical roller bearing with both displacement compensation function and vibration reduction function |
| CN105526257A (en) * | 2016-02-17 | 2016-04-27 | 张广 | Angular contact ball bearing with both displacement compensation function and vibration reduction function |
| CN114704643A (en) * | 2022-03-18 | 2022-07-05 | 北京科技大学 | High-rotation-speed magnetic liquid sealing structure and sealing ring surface air pressure adjusting method |
-
2006
- 2006-05-25 CN CN 200620116050 patent/CN200989445Y/en not_active Expired - Fee Related
Cited By (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105508434A (en) * | 2016-02-17 | 2016-04-20 | 张广 | Self-aligning ball bearing with displacement compensation function and damping function |
| CN105508428A (en) * | 2016-02-17 | 2016-04-20 | 张广 | Cylindrical roller bearing with displacement compensation function and damping function |
| CN105508433A (en) * | 2016-02-17 | 2016-04-20 | 张广 | Double-row cylindrical roller bearing with angle compensation function and damping function |
| CN105526264A (en) * | 2016-02-17 | 2016-04-27 | 张广 | Self-aligning ball bearing with angle compensation function and damping function |
| CN105526263A (en) * | 2016-02-17 | 2016-04-27 | 张广 | Double-row cylindrical roller bearing with both displacement compensation function and vibration reduction function |
| CN105526257A (en) * | 2016-02-17 | 2016-04-27 | 张广 | Angular contact ball bearing with both displacement compensation function and vibration reduction function |
| CN114704643A (en) * | 2022-03-18 | 2022-07-05 | 北京科技大学 | High-rotation-speed magnetic liquid sealing structure and sealing ring surface air pressure adjusting method |
| CN114704643B (en) * | 2022-03-18 | 2023-02-24 | 北京科技大学 | High-rotation-speed magnetic liquid sealing structure and sealing ring surface air pressure adjusting method |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| C19 | Lapse of patent right due to non-payment of the annual fee | ||
| CF01 | Termination of patent right due to non-payment of annual fee |