JPH0133884Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention relates to a magnetic fluid seal installed between a housing and a rotating body in various types of equipment.

[Prior art and its problems]

Conventionally, this type of magnetic fluid seal has a pair of fixing rings 3 and 4 made of magnetic material disposed between a housing 1 and a rotating shaft 2 so as to face each other in the shaft axial direction, as illustrated in FIG. At the same time, the magnetic ring 5 is adsorbed and held between the fixed rings 3 and 4, and the gaps a and a between the outer circumferential surface of the rotary shaft 2 and the inner circumferential surfaces of both the fixed rings 3 and 4 are magnetized. As shown in FIG. 3, there are two fixing rings 3,
A magnet ring 5 fixed to the rotating shaft 2 side is arranged between the two fixed rings 3 and 4, and magnetic fluids 6 and 6 are placed in gaps b and b formed between the magnet ring 5 and both fixed rings 3 and 4. It has a structure in which the magnetic fluids 6, 6 can be held by enclosing them and forming lines of magnetic force shown by solid arrows.

However, with the conventional structure described above,
In the former case, it is extremely difficult to maintain the clearance for holding the magnetic fluids 6, 6 against the radial vibration of the rotating shaft 2, and in the latter case against the axial play of the rotating shaft 2. However, since the circumferential speed (PV value) of the magnetic ring 5 is high, the amount of leakage is also high, and when the user installs the seal into the device, it is necessary to set the clearance between the magnetic ring and the fixed ring (magnetic material). However, there were various disadvantages such as the extremely difficult control of the amount of magnetic fluid to be filled and the method of filling the magnetic fluid.

[Purpose of invention]

The present invention was developed based on the above-mentioned circumstances, and allows for rattling in the radial and axial directions of the rotating body, reduces the amount of leakage due to a decrease in the PV value, and allows users to incorporate it into equipment. The object of the present invention is to provide a magnetic fluid seal that can facilitate the operation.

[Summary of the idea]

In order to achieve the above purpose, the present invention:
A magnetic ring is disposed in a floating state via a magnetic fluid between a rotating ring and a stationary ring which are placed opposite to each other on concentric circles, and the whole is combined and integrated.

[Example of idea]

The present invention will be explained below with reference to an embodiment shown in FIG.

As shown in FIG. 1, 10 in the figure is a magnetic fluid seal according to the present invention, which is interposed between the housing 1 and the rotating shaft 2 shown in FIGS. 2 and 3. The seal 10 includes a rotary ring 11 having a cross-sectional shape, which is formed by assembling and joining a pair of left and right divided bodies made of magnetic material, and a fixed ring 12 having a cross-sectional shape, which are concentrically opposed to each other, and both rings 11, 12 are arranged concentrically opposite each other. The magnetic ring 13 is placed in a floating state in the space formed between the two, and the magnetic fluids 14 and 15 are filled in the gaps between the respective rings 11 and 12 and the magnetic ring 1, respectively. It can be held by magnetic lines of force (indicated by solid arrows). The rotary ring 11 is fixed to the rotary shaft 2 side via a buffer rubber 16, and the fixed ring 12 is fixed to the housing 1 side via a buffer rubber 17, so that the entire body is combined and integrated. has been made into

Therefore, the seal 10 according to the present invention described above
Since the magnet ring 13 is suspended between the magnetic bodies consisting of the rotating ring 11 and the stationary ring 12, it is possible to allow the rotating shaft 2 to wobble in the radial and axial directions. The relative velocity with the body is halved, thereby reducing the PV
The value decreases, making it possible to reduce the amount of leakage. In addition, since the entire seal is integrated, the user can easily integrate it into the device by simply fitting it between the housing 1 and the rotating shaft 2 using an appropriate jig, etc. become.

[Effect of idea]

As explained above, according to the present invention, since the magnet ring is placed in a floating state between the magnetic bodies and the whole is combined and integrated, it is possible to tolerate rattling in the radial and axial directions relative to the rotating body to a certain extent. Moreover, since the relative speed between the two can be halved, it is possible to lower the PV value and the amount of leakage, and it has excellent effects in that it can be easily integrated into equipment by the user. play.

[Brief explanation of the drawing]

FIG. 1 is a schematic cross-sectional view of a main part showing one embodiment of a magnetic fluid seal according to the present invention, and FIGS. 2 and 3 are schematic cross-sectional views of main parts showing two examples of conventional magnetic fluid seals. . 10... Seal, 11... Rotating ring, 12...
... Fixed ring, 13 ... Magnet ring, 1
4,15...Magnetic fluid.

Claims (1)

[Scope of utility model registration request] A magnetic fluid seal characterized in that a magnetic ring is placed in a floating state via a magnetic fluid between a rotating ring and a stationary ring that are opposed to each other on a central circle, and the whole is combined and integrated.