JPH11141560A - Magnetic fluid seal - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a low-cost magnetic fluid seal fixed to a housing or a bearing and exerting a sealing effect, in which one sealing member has a high sealing property and which excels in mounting workability. SOLUTION: A magnetic fluid seal is to establish sealing between a bearing part 1 and a rotary shaft 1a, wherein a ferromagnetic substance is included in an elastic material and therefrom a magneto-elastic ring body 3 is shaped consisting of a fitting mounting part 3a and a body part 3b, and a magnetic pole plate 4 is held pinchedly by the ring 3 so that a sealing member is accomplished. The ring 3 is magnetized, and the gap to a member confronting the magnetic pole plate 4 is filled with a magnetic fluid 2. The resultant seal exerts a high sealing property, excels in the mounting workability, is advantageous for the molding process, can be mounted and removed easily and effectively, and has a strong fixing and retaining force.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hermetic seal fixed to a housing or a bearing to perform a sealing action.
More specifically, the present invention relates to a magnetic fluid seal in which a magnetic fluid is interposed in a relatively rotating narrow portion to achieve sealing.

[0002]

2. Description of the Related Art Conventionally, as a magnetic seal device for sealing using a magnet and a magnetic fluid, as shown in FIG. 2 in detail with reference to the drawings, a rotary shaft (1a) is surrounded and rotated. 1a) An annular permanent magnet (5) and a pair of annular magnetic pole plates (6) in close contact with both surfaces of the annular permanent magnet (5) are arranged while maintaining a space between the annular permanent magnet and the annular permanent magnet (5). 5), a ring-shaped magnetic pole plate (6), and a rotating shaft (1a) constitute a magnetic circuit, and a magnetic fluid (2) is filled into a small gap between the rotating shaft (1a) and the ring-shaped magnetic pole plate (6) for sealing. The function was demonstrated. In the formation of the ring-shaped permanent magnet (5), a ferromagnetic material such as ferrite is fired and pulverized, then molded into a desired shape, sintered, and magnetized to form a permanent magnet. This is a general molding method.

[0003]

However, this type of magnetic fluid seal is fixed by press-fitting to the mounting portion (1c) as shown in FIG. It requires a fitting jig (not shown), and when it is installed in this way, it requires a great deal of time to remove it in reverse and does not allow easy removal, and wear and inspection It is difficult to replace and exchange in such cases. If the two members to be fitted are easily slid so as to avoid the press-fitting, the fitting portion is a metal-to-metal contact, so that there is much problem in the sealing performance of the mounting portion (1c), There is a drawback that an auxiliary fixing member such as a press ring (7) as shown in FIG.

SUMMARY OF THE INVENTION An object of the present invention is to eliminate such many disadvantages which must be solved and to provide an inexpensive magnetic fluid seal in which one sealing member has high sealing properties and is excellent in mounting workability. .

[0005]

The present invention will be described with reference to the drawings. As shown in FIG. 1, the present invention is mounted on a shaft support (1b) such as a housing or a bearing, and the shaft support (1b) and the rotary shaft (1a) are mounted. The magnetic fluid seal (2) seals the inside and the outside with a magnetic fluid (2). The ferromagnetic material is mixed with an elastic material made of synthetic rubber or synthetic resin or the like, and the fitting mounting portion (3a) and the main body ( 3b) is formed, and a magnetic pole plate (4) made of metal is sandwiched and arranged from both sides of the magnetic elastic ring (3) to form a seal member. At this time, the magnetic elastic ring (3) of the seal member is magnetized, and the gap between the pole plate (4) and the member facing the magnetic pole plate (4) is filled with the magnetic fluid (2) to complete the magnetic fluid seal.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS As described above, the present invention relates to a magnetic fluid seal using a magnetic fluid (2), wherein a fitting mounting portion (3a) and a main body (3b) are made of a flexible magnetic elastic ring. A sealing member is formed by integrally forming a magnetic pole plate (4) from both sides of the body (3), and the magnetic elastic ring (3) simplifies the structure and mounting work. It plays a dramatic improvement in sex. In the formation, as shown in FIG. 1, an elastic material in which a ferromagnetic material made of synthetic rubber or synthetic resin is mixed, and a metal pole plate (4) to which a base treatment and an adhesive are applied in advance are formed. It is put into a mold and vulcanized under pressure and heat to form the fitting mounting part (3a) and the main body part (3b). At the same time, the adhesive integration with each of the magnetic pole plates (4) is performed. A sealing member is formed.

Before mounting the completed seal member,
The sealing member is inserted into a magnetic field that generates N and S poles, and the magnetic elastic ring (3) is magnetized to form a permanent magnet.
Then, as shown in FIG. 1, this sealing member is elastically deformed into the fitting mounting portion (3a) of the magnetic elastic ring (3) into the fitting groove (1d) of the shaft support portion (1b, here, the outer ring portion of the bearing). At the very least, push it in and insert it, compressing its tip to secure it. Then, a shaft support (1) facing the magnetic pole plate (4)
b) is filled with the magnetic fluid (2) to complete the magnetic fluid seal.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In order to carry out the present invention, a magnetic elastic ring (3) constituting a magnetic fluid seal is magnetized to become a permanent magnet and a main body (3b) and a fitting mounting portion formed in connection with the main body. (3a), and the expandability of the structure is enhanced by integrally forming the mounting portion and the magnet portion with an elastic body. In other words, the elastic material made of synthetic rubber or synthetic resin shows excellent moldability even when a ferromagnetic material is mixed, and has better mounting, fixing and sealing properties than conventional metal materials. It is excellent in any performance such as removability and the like, and not only enables molding in an ideal shape as a seal member, but also maintains a high level in performance.

[0009] Further, in bonding and integrating an elastic material mixed with a ferromagnetic material and a magnetic pole plate (4) made of metal, the pole plate (4) formed with predetermined dimensions is subjected to degreasing or surface treatment. This is selected from adhesives such as phenolic resin, epoxy resin or isocyanate resin, applied, baked and dried. Thereafter, it is efficient to put the magnetic pole plate (4) having the adhesive formed on its surface together with the elastic material into a mold having a desired cavity shape, heat and compress, promote vulcanization, and form and adhere. It is a reliable bonding method. When the magnetic fluid seal thus formed is mounted in the fitting groove (1d) and the magnetic fluid (2) is injected, the fitting mounting portion (3a) is used.
By using the elasticity of the elastic body, a predetermined amount of injection can be performed while confirming the filling amount by temporarily shifting the elastic body laterally.

[0010]

According to the present invention having the above-described structure, an inexpensive magnetic fluid seal having high sealing performance and excellent mounting workability can be obtained. Play. The mounting part and the magnet part can be integrally press-molded with an elastic body, so that it is not only superior in molding, but also excellent in attachment and detachment, strong in fixing and holding power, and elastic adhesion. It is an ideal sealing member, such as having a good sealing performance.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an embodiment of the present invention.

FIG. 2 is a sectional view showing another conventional structure not using the present invention.

[Explanation of symbols]

 1a Rotating shaft 1b Shaft support 1c Attachment 1d Fitting groove 2 Magnetic fluid 3 Magnetic elastic ring 3a Fitting attachment 3b Main body 4 Magnetic pole plate 5 Ring permanent magnet 6 Ring pole plate 7 Pressing ring

Claims (1)

[Claims] A magnetic fluid seal interposed between a shaft support and a rotating shaft for sealing the space between the shaft support and a rotary shaft by using a magnetic fluid. A magnetic pole plate made of metal is sandwiched and arranged from both sides of the magnetized magnetic elastic ring, and a magnetic fluid is filled between the pole plate and a member opposed to the magnetic pole plate. A magnetic fluid seal.