JPS6340652Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a sealing device using a magnetic fluid, and more particularly to a sealing device that uses a support plate and a magnetic flux plate to transmit magnetic poles and achieves sealing with an axial magnetic pole.

A detailed description will be given below with reference to the drawings.

Conventionally, as a seal device using a magnet and a magnetic fluid, as shown in Fig. 1, a rotating shaft 1 is used.
An annular permanent magnet 2 and a pair of annular magnetic pole plates 3 that are in close contact with both surfaces of the annular permanent magnet 2 are arranged so as to surround the annular permanent magnet 2 and maintain a space between the annular permanent magnet 2 and the circumferential surface of the shaft 1. The magnetic pole plate 3 and the shaft 1 constituted a magnetic circuit, and a small gap between the shaft 1 and the magnetic pole plate 3 was filled with magnetic fluid 4 to exert a sealing function in the radial direction.

However, when the housing 5 to which this type of seal device is attached is made of a magnetic material, the magnetic flux is short-circuited and the magnetic flux density of the seal portion filled with the magnetic material 4 decreases.
Furthermore, in order to use shaft 1 as a magnetic circuit, shaft 1
It is essential that the sleeve be made of a magnetic material, and in the case of a non-magnetic material, a sleeve made of a magnetic material must be attached to the circumferential surface of one of the shafts.

Furthermore, since the bearing part and the seal part are separate structures, it has many drawbacks such as troublesome assembly and poor workability.

The present invention provides an epoch-making sealing device that eliminates the drawbacks of the prior art described above, improves sealing performance, and simplifies assembly work.

As shown in Fig. 2, the bearing sealing structure of the present invention consists of an annular permanent magnet 2 whose outer periphery and inner periphery have different polarities.
and a magnetic pole ring 6 that is in close contact with both circumferential ends of the annular permanent magnet 2 and transmits the magnetic pole in the axial direction, and has a fitting part on one side circumference formed of a non-magnetic material such as synthetic rubber or synthetic resin. It is fixed by a support plate 7, has a fitting part on the periphery opposite to the fitting part position of the support plate 7, is made of a magnetic material, and preferably has a cross section of approximately L.
The structure is such that a magnetic flux ring 8 having a letter-shaped shape faces the magnetic pole ring 6 of the support plate 7 in the radial direction with a small gap therebetween, and the small gap is filled with the magnetic fluid 4.
The magnetic pole ring 6 preferably has an L-shaped cross section, and its bent portion is integrally fixed to the support plate 7.

This sealing device having a magnetic circuit in the axial direction produces excellent effects that cannot be imitated by conventional sealing devices. That is, since the annular permanent magnet 2 and the magnetic pole ring 6 are wrapped and fixed by the support plate 7 made of a non-magnetic material that does not allow magnetism to escape to other parts, the magnetic force acts only on the magnetic flux ring 8. In addition, since the magnetic flux ring 8, which is located in an independent position, has an extremely small portion where magnetism escapes to other parts, a strong magnetic circuit is created using the magnetic fluid 4 interposed between the magnetic flux ring 8 and the magnetic pole ring 6 as a magnetic flux path. Therefore, the magnetic fluid 4 is perfectly held between the magnetic flux ring 8 and the magnetic pole ring 6 without being dispersed, and high sealing performance is achieved without being affected by shaft rotation from high to low speeds. It is to be maintained.

Furthermore, since the supporting plate 7 has a structure in which the peripheral edge located opposite to the fixed side peripheral edge has only a minute gap with the opposing member, it functions similarly to a conventional sealing device having a labyrinth effect. The support plate 7 prevents the intrusion of foreign matter such as dirt and dust, and has the great effect of reducing the amount of evaporation of the magnetic fluid 4 located inside. Furthermore, although conventionally a magnetic metal rod had to be used for the shaft, this is not necessary at all in the present invention, which is very advantageous in terms of rust and cost.

Although FIGS. 2 and 3 show a state in which the support plate 7 is located on the outside of the bearing part and the magnetic flux ring 8 is located on the inside, it is also possible to achieve sealing with the opposite configuration. In this case, the magnetic flux ring 8 has a structure in which the periphery located opposite to the periphery of the fitting part has a small gap with the opposing member, but this is required because sufficient sealing is ensured without any reduction in the above-mentioned effects. It may be configured according to the location and purpose of use.

In addition, in order to further improve the magnetic flux effect of the magnetic flux rings 8 in independent positions and to increase the amount of magnetic fluid 4 held, the magnetic pole rings 6 are arranged as shown in FIG.
By providing at least one beat ring 9 that protrudes or recesses on the peripheral surface of the magnetic flux ring 8 that faces the magnetic flux ring 8 with a small gap, the magnetic force transmitted from the magnetic pole ring 6 can be made stronger. It can be configured as a magnetic circuit, and as shown in FIG. If the fluid 4 is filled and stored, it is possible to maintain semi-permanent sealing together with the effect of suppressing the amount of evaporation described above.

Further, as shown in FIG. 3, if the fitting part of the magnetic flux ring 8 is made into a cylindrical shape, and the support plate 7 is inserted into the cylindrical part, the cylindrical end 10 is bent inward to form a J-shape. The support plate 7 is loosely fitted into the ring body 8 to form the sealing device into an integral structure, so that it does not fall apart during storage and transportation.
Moreover, the fitting work into the bearing part can be done in an extremely short time.

In addition, in FIGS. 2 and 3, the sealing device of the present invention is described in detail as being fitted between the inner ring and the outer ring of the bearing, but as shown in FIG. There is no problem even if it is fitted to an external material such as No. 12, and even in this case, the above-mentioned function and effect can be fully exhibited, and the place where it is fitted does not matter.

As explained above, this invention has an innovative structure that aims to seal the magnetic circuit in the axial direction, and creates a strong magnetic flux path without absorbing magnetism in other parts, creating a perfect seal. This is an ideal bearing sealed structure that is easy to assemble.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a conventional magnetic seal. FIG. 2 is a sectional view of the bearing sealing structure of the present invention. FIG. 3 is a sectional view showing another embodiment of the bearing sealing structure of the present invention. FIG. 4 is an enlarged partial sectional view showing another embodiment of the present invention. FIG. 5 is a sectional view showing another embodiment of the present invention. DESCRIPTION OF SYMBOLS 1... Shaft, 2... Annular permanent magnet, 3... Annular magnetic pole plate, 4... Magnetic fluid, 5... Housing, 6...
...Magnetic pole ring, 7...Support plate, 8...Magnetic flux ring, 9
...Beat ring, 10...tube end.

Claims (1)

[Claims for Utility Model Registration] (1) In a magnetic seal structure that seals the bearing part;
An annular permanent magnet whose outer and inner peripheries have different polarities and a magnetic pole ring that is in close contact with both peripheral ends of the annular permanent magnet and transmits magnetic poles in the axial direction are made of a non-magnetic material such as synthetic rubber or synthetic resin. A magnetic flux ring made of a magnetic material, supported by a support plate integrally formed with a support plate having a fitting part on one side periphery, and having a fitting part on the periphery opposite to the position of the fitting part of the support plate. A magnetic sealing structure characterized in that the magnetic pole rings of the support plate face each other in the radial direction with a minute gap therebetween, and the minute gap is filled with a magnetic fluid. (2) The magnetic sealing structure according to claim 1 of the utility model registration claim, wherein the peripheral edge of the non-magnetic support plate located opposite to the fitting part has a minute gap with the opposing member. . (3) The magnetic sealing structure according to claim 1 of the utility model registration claim, wherein the peripheral edge of the magnetic flux ring, which is a magnetic material, located opposite to the fitting part has a minute gap with the opposing member. . (4) A utility model characterized in that at least one protruding or recessed bead ring is provided on the circumferential surface of the magnetic flux ring, which is the part that faces the magnetic pole ring with a minute gap. Scope of registration claims 1st
3. Magnetic sealing structure according to item 3 and item 3.