JPS6347568A - Sealing device - Google Patents

Abstract

PURPOSE:To make it sealable stably even in a high speed area, by installing a circumferential groove in an inner circumferential surface of a ring magnet at the fixed member side. CONSTITUTION:A concave sectional ring magnet 4 having a groove 4a is locked to an inner circumferential surface of a fixed member 2. Magnetic flux is passed through this groove 4a in parallel with the axial direction of a turning shaft 1 by the ring magnet 4 whereby a magnetic fluid 6 is held. In addition, the elastically deformable disc 5 of a plastic or metal sheet or the like attached to the turning shaft 1 is inset in this groove 4a. With this constitution, it is stably sealable even in a high speed area.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention mainly relates to a sealing device for a semiconductor device that requires ultra-clean dust, and is particularly suitable for sealing dust from a drive part. It's about the sealing device.

[Conventional technology]

A conventional sealing device, as described in Japanese Patent Application Laid-Open No. 59-93817, injects magnetic fluid into a circumferential groove where a magnetic force acts, and inserts a cylinder protruding from a rotating member into this circumferential groove. It is inserted to form a sealing mechanism.

[Problem that the invention seeks to solve]

In the above-mentioned conventional technology, there is a problem in that the centrifugal force applied to the magnetic fluid is large in the high-speed rotation range where the shaft rotates at high speed, and the magnetic fluid is washed away due to the action of this centrifugal force, deteriorating the sealing performance.

An object of the present invention is to provide a sealing device f that can stably seal even in a high-speed rotation range.

[Rounding method to solve problems]

The above-mentioned object of the present invention is to provide a circumferential groove in the inner circumferential surface of an annular magnet on the fixed member side, fit a disk protruding from the rotating shaft into the groove in a non-contact manner, and inject a magnetic fluid into the groove. This is accomplished by constructing a sealing mechanism using

[Effect]

The annular magnet fixed to the fixed member has a function of holding the magnetic fluid in its inner groove, and a disk protruding from the rotating shaft is fitted into the groove in which the magnetic fluid remains. As a result, even during high-speed rotation, the magnetic fluid does not scatter outside the groove due to centrifugal force, and stable sealing performance can be obtained.

〔Example〕

- Hereinafter, one embodiment of the present invention will be explained using the drawings.

FIG. 1 shows an embodiment of the apparatus of the present invention.

In this figure, an annular magnet 4 having a concave 1lfr surface and having tg4a on the inner circumferential surface is fixed to the fixed member 2. As shown in FIG.

A magnetic flux passes through the groove 4aK in parallel to the axial direction of the rotary shaft 1 by the 8-section magnet 4, and the magnetic fluid 6 can be held therein. An elastically deformable disc 5 made of plastic or a thin metal plate, to which a rotating shaft IK is attached, is fitted into the groove 4a.

With this configuration, even if the J14111 rotates at high speed and a large centrifugal force is applied to the magnetic fluid, the magnetic fluid 6 will not flow out of J14a, so it will remain stable up to the high speed rotation range. It can be sealed.

FIG. 2 shows another embodiment of the device according to the invention, which includes an annular magnet with a concave cross section.

The magnet is divided into two annular magnets 10a and 10b, and the disk 5 provided on the rotating shaft 1 can be easily assembled.

Since the magnetic flux passes through the mating surfaces of the annular magnets 10a and 10b, the magnetic fluid 6 does not leak out from the mating surfaces. According to this embodiment, it is possible to realize a sealing device that is easy to assemble.

FIG. 3 shows still another embodiment of the device of the present invention, in which an elastically deformable magnet such as a rubber magnet is used as the magnet material having a concave cross section.

With this configuration, even if the disc 5 attached to the rotating shaft is rigid, it can be incorporated. Even if the rotating shaft 1 rotates at high speed, the disc 5 will not be affected by large centrifugal force. Stable sealing performance can be obtained without damage.

〔Effect of the invention〕

According to the present invention, it is possible to provide a sealing device that can stably seal even in a high-speed rotation range.

[Brief explanation of the drawing]

1 to 3 are longitudinal cross-sectional views showing embodiments of the sealing device of the present invention.

Claims (1)

[Claims] 1. In a sealing device for sealing dust from a dust source between a fixed member and a rotating member, an annular magnet having a circumferential groove is fixed to the inner circumference of the fixed member. A sealing device characterized in that a disc that fits into the groove in a non-contact manner is fixed to a rotating member, and a magnetic fluid is injected into the groove. 2. The sealing device according to claim 1, wherein the annular magnet having a circumferential groove is composed of a plurality of magnetic materials. 3. The sealing device according to claim 1, wherein the annular magnet having the circumferential groove is an elastically deformable magnet.