JPH04258576A - Shaft seal device - Google Patents

Abstract

PURPOSE:To provide a shaft seal device preventing outflow of liquid magnetic fluid and achievable to prevent outflow of fluid of such as vapor of oil inside an apparatus, with high reliability. CONSTITUTION:This device is equipped with ring-like side plates 2 consisting of magnetic material arranged into the axial direction via a magnet net 1 at an interval in plural numbers, labyrinth channels 5 provided at least one of either the side plate or a rotation shaft 4 of magnetic material penetrating the bore part of the side plate 2, liquid magnetic fluid 6 filled up in the labyrinth channels, outer walls 7 of non-magnetic material closely sealing up the outer peripheries of the neighboring side plates 2 to form a pressure governing chamber 8 together with side plates 2, and a pressure governing device 10 communicated with the pressure governing chamber 8 to adjust pressure inside the pressure governing chamber.

Description

[Detailed description of the invention]

[Purpose of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to a shaft sealing device for preventing fluid leakage.

0002

2. Description of the Related Art Sealing means include packing/gasket seals, oil seals, mechanical seals, labyrinth seals, floating seals, and magnetic fluid seals.

Among these, magnetic fluid seals create a stable shaft seal not only in the stationary gap but also in the gap between the stationary part and the rotating part by configuring the shaft seal part with a magnetic field and placing liquid magnetic fluid there. , has recently been widely applied and attracting attention.

0004

However, even when liquid magnetic fluid is used, the fluid sometimes flows away and the shaft seal is broken.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a shaft sealing device that can prevent liquid magnetic fluid from flowing out and prevent fluids such as oil vapor inside the device from flowing out with high reliability.

[Configuration of the invention]

[0007]

[Means for Solving the Problems] In order to achieve the above object, the present invention includes an annular side plate made of a plurality of magnetic materials arranged at intervals in the axial direction via magnets, and an inner diameter portion of the side plate. A labyrinth groove provided in at least one side of the rotating shaft of the magnetic material passing through the labyrinth groove, a liquid magnetic fluid filled in the labyrinth groove, and a non-magnetic material that seals the outer periphery of the adjacent side plate to form a pressure regulating chamber together with the side plate. It includes an outer wall and a pressure regulating device that communicates with the pressure regulating chamber and adjusts the pressure inside the pressure regulating chamber.

[0008]

[Operation] With the above structure, the magnet forms a magnetic field through the side plate and the rotating shaft, which strongly holds the liquid magnetic fluid and applies a slight indoor pressure to the pressure regulating chamber. Even if oil or oil vapor exists with some pressure on the outside of the side plate, this oil or oil vapor will not leak to the outside.

[0009]

EXAMPLES Example 1 A first example of the present invention will be described below with reference to FIG.

Magnets (1) having N and S poles in the axial direction are arranged between the circumferential upper surfaces, thereby providing an annular side plate (2) made of a magnetic material and arranged at intervals.

[0011] The inner diameter part of the side plate (2) has annular teeth (
3), which penetrate through the rotating shaft (4) made of a magnetic material. A labyrinth groove (5) formed by the rotating shaft (4) and the teeth (3) of the side plate is filled with a liquid magnetic fluid (6).

[0012] An outer wall (7) made of a non-magnetic material is airtightly attached to the outer periphery of the adjacent side plates (2) to form a pressure regulating chamber (8) together with the side plates (2). A pressure regulator (10) is connected to the outer wall (7) via a pipe (9).

On the left side of the pressure regulation chamber (8) in FIG. 1, there is a fluid (11), such as oil or oil vapor, which is similar to the one except for the pressure regulation device (10), and which should be prevented from leaking non-magnetic material. Fluid tank (
12) is provided with an outer wall (7a).

Then, the pressure in the pressure regulating chamber (8) is adjusted to be slightly higher than the pressure in the fluid tank (12).

Next, the operation of the first embodiment will be explained. The liquid magnetic fluid (6) is attracted into the labyrinth groove (5) by the magnetic field of the magnet (1), so even if a slightly high pressure is applied to the pressure regulating device, the gas inside the pressure regulating chamber (8) will not leak. . The fluid pressure in the adjacent fluid tank (12) is adjusted to the pressure regulating chamber (8).
Since the internal fluid (11) is slightly lower than that, there is no possibility of leakage of the internal fluid (11). Example 2 Next, a second example will be described with reference to FIG. 2.

In this second embodiment, the teeth (3) are connected to the rotating shaft (
4) The rest is the same as in Example 1 except that it is provided on the side.

[0017] Even in this manner, the same effects as in the first embodiment can be obtained.

[0018] Furthermore, in the present invention, the teeth (3) are attached to the side plate (2).
and the rotating shaft (4). In addition, the pressure regulating chamber (
8) may be arranged in plural in the axial direction.

[0019]

[Effects of the Invention] As explained above, according to the present invention,
The liquid magnetic fluid is attracted into the labyrinth groove by the magnetic field of the magnet (1), so even if a slightly high pressure is applied to the pressure regulating device, the gas inside the pressure regulating chamber will not leak, and therefore the oil adjacent to the pressure regulating chamber will not leak. Even if there is a fluid tank containing oil or oil vapor, the oil or oil vapor will not leak, and a highly reliable shaft sealing device can be provided.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view showing a first embodiment of a shaft sealing device of the present invention.

FIG. 2 is a longitudinal sectional view showing a second embodiment of the invention.

[Explanation of symbols]

1 Magnet 2 Side plate 4 Rotation axis 5 Labyrinth groove 6 Liquid magnetic fluid 7. External wall 8 Pressure regulation room 10 Pressure regulating device

Claims (1)

[Claims] 1. A labyrinth groove provided in at least one of an annular side plate made of a magnetic material arranged at intervals in the axial direction via magnets, and a rotating shaft of the magnetic material passing through an inner diameter portion of the side plate. The liquid magnetic fluid filled in the labyrinth groove and the outer wall of non-magnetic material that seals the outer periphery of the adjacent side plates to form a pressure regulation chamber together with the side plates communicate with the pressure regulation chamber to adjust the pressure in the pressure regulation chamber. A shaft sealing device comprising a pressure regulating device.