JP2568731Y2 - Vacuum chamber dustproof device - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dustproof device for a vacuum chamber having a rotating part in which a shaft member penetrating through the vacuum chamber and the vacuum chamber relatively rotate.

[0002]

2. Description of the Related Art For example, when a shaft member 2 is rotated with respect to a vacuum chamber 1 as shown in FIG. 1, the inside of the vacuum chamber 1 is maintained at a desired vacuum state and a clean environment with respect to the outside of the vacuum chamber 1. There is a need to.

Conventionally, as shown in FIGS. 5 and 6,
The magnet 5 is sandwiched between the magnetic pole members 4A and 4B, and a gap between the magnetic pole members 4A and 4B and the magnetic shaft member 2 in the radial direction is filled with a magnetic material 3 having fluidity. The magnetic bodies 3A and 3B are constrained in the annular gap between the inner peripheral surface of the magnetic pole member 4 and the outer surface of the shaft member 2 by the lines of magnetic force formed by the magnets 5 to form the magnetic fluid seal mechanism 6. I have. The magnetic fluid sealing mechanism 6 protects the rotating unit from dust and air.

[0004] The restraining force of the magnetic body 3 becomes the vacuum holding ability. However, when a normal magnetic pole member 4 and magnet 5 are used, there is a limit to the pressure difference at which a set of magnetic fluid sealing mechanisms 6 can be sealed. Yes, and generally, when maintaining vacuum,
The magnetic fluid sealing mechanism 6 is provided in multiple stages.

[0005]

By the way, as shown in FIG. 5, if the magnetic fluid sealing mechanisms 6 are provided in multiple stages, there is a disadvantage that the magnetic fluid sealing mechanism 6 becomes longer in the major axis direction. In addition, since the magnetic fluid seal mechanism 6 having a complicated shape, which is complicated to process, is used in multiple stages, there is a disadvantage that the apparatus becomes expensive.

An object of the present invention is to provide an apparatus for maintaining a desired vacuum state and a clean environment in a vacuum chamber having a shaft part penetrating the vacuum chamber and a rotating part in which the vacuum chamber relatively rotates. Accordingly, it is an object of the present invention to provide an inexpensive vacuum chamber dust-proof device that has a relatively small size in the major axis direction of a rotating part that rotates relatively.

[0007]

SUMMARY OF THE INVENTION The present invention is applied to a dustproof device for a vacuum chamber having a rotating part in which a shaft member penetrating the vacuum chamber and the vacuum chamber relatively rotate. The feature is that a magnetic pole member provided with an O-ring on the outer periphery of the shaft member, concentric with the shaft member, provided with a gap in the radial direction and separated in the long axis direction, A magnetic fluid sealing mechanism including a magnetic force generator sandwiched between magnetic pole members and a magnetic material having fluidity filled in a radial gap between the magnetic pole member and the shaft member is provided on the inner wall side of the vacuum chamber with respect to the O-ring. And a communication path communicating the rotating part between the magnetic fluid sealing mechanism and the O-ring and the inside of the vacuum chamber is provided, and a dustproof filter is provided in the communication path. is there.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to the illustrated embodiments. In FIG. 2, reference numerals 1 and 2 denote a relatively rotating vacuum chamber 1 and a shaft member 2, for example, to which the vacuum chamber 1 is fixed. The shaft member 2 has magnetism and the bearing 1
It is rotatably supported by the vacuum chamber 1 by 0 and 10, and is rotated by a driving device (not shown). 4A,
Reference numeral 4B denotes a disk-shaped magnetic pole member provided in the vacuum chamber 1, and a certain gap is formed between the inner peripheral surface of the magnetic pole member 4 and the outer peripheral surface of the shaft member 2. Numerals 3A and 3B denote flowable magnetic materials. The magnetic material 3 is placed in an annular gap between the inner peripheral surface of the magnetic pole member 4 and the outer surface of the shaft member 2 by a magnetic force generating device 5, for example, a line of magnetic force formed by a magnet. Be bound.
The configuration of the magnetic fluid sealing mechanism 6 by the above 3 to 5 is the same as the conventional one. Reference numeral 7 denotes an O-ring provided on the outer periphery of the shaft member 2, reference numeral 8 denotes a communication path communicating the inside of the vacuum chamber 101 with the space 11 of the rotating unit, and reference numeral 9 denotes a dustproof filter provided in the communication path 8. .

By the way, even when the shaft member 2 is rotated, since the O-ring 7 is provided between the vacuum chamber 1 and the shaft member 2, the inside of the vacuum chamber 101 is maintained at a desired vacuum state. . If you use it for a long time,
O-ring 7 disposed on shaft member 2 with rotation of shaft member 2
Dust is generated by friction between the magnetic fluid seal mechanism 6 and the dustproof filter 9.
Therefore, the inside of the vacuum chamber 101 is maintained in a desired clean environment. In addition, the communication passage 8 connects the inside of the vacuum chamber 101 with the space 11 of the rotating part, so that there is no pressure difference. Therefore, the magnetic fluid sealing mechanism 6 only has to perform dust prevention on the rotating part. Need only be provided in the vacuum chamber 1 in one stage. Thereby, the dimension in the long axis direction can be shortened. Further, since only one set of the magnetic fluid seal mechanism 6 is used, the cost is reduced.

FIG. 3 is a diagram showing another embodiment of the present invention.
In the shaft member 2, a shaft member 12 having the same magnetism is further provided.
Magnetic fluid seal mechanism 13, O-ring 14, communication passage 15,
Since the shaft member 2 and the shaft member 16 are arranged concentrically in a structure in which the bearings 16 and 16 and the dustproof filter 91 are arranged, it can be applied to, for example, a two-axis vacuum clean robot. it can.

FIG. 4 is a diagram showing a modification of FIG.
The communication passage 17 is provided in the shaft member 2. With this configuration, the communication path 8 is provided in the vacuum chamber 1.
Eliminates difficult processing.

[0012]

As is apparent from the above description, an O-ring is provided at a rotating portion between a relatively rotating vacuum chamber and a shaft member, and a magnetic fluid sealing mechanism is provided closer to the inner wall of the vacuum chamber than the O-ring. And the magnetic fluid sealing mechanism and O
Since a communication path communicating the rotating part between the ring and the inside of the vacuum chamber is provided, and a filter for preventing dust is provided in the communication path, a desired vacuum state is maintained in the vacuum chamber by the O-ring. The inside of the vacuum chamber is maintained in a desired clean environment by the magnetic fluid sealing mechanism and the filter. Further, since there is no differential pressure on both sides of the magnetic fluid seal mechanism due to the communication path, the magnetic fluid seal mechanism only needs to perform dust prevention on the rotating part, and only needs to be provided in the vacuum chamber at one stage. As a result, the dimension in the long axis direction can be shortened, and the cost is low because only one set of the magnetic fluid sealing mechanism is used.

[Brief description of the drawings]

FIG. 1 is a view showing a vacuum chamber having a rotating part, which is the object of the present invention.

FIG. 2 is a sectional view showing a main part of the first embodiment of the present invention;

FIG. 3 is a sectional view showing a main part of another embodiment of the present invention.

FIG. 4 is a sectional view showing a modification of FIG. 2;

FIG. 5 is a sectional view showing a main part of a conventional example.

FIG. 6 is an enlarged sectional view of a magnetic fluid sealing mechanism 6;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Vacuum chamber 2 ... Shaft member 3 ... Magnetic body 4 ... Magnetic pole member 5 ... Magnetic force generator 6 ... Magnetic fluid sealing mechanism 7 ... O-ring 8 ... Communication path 9 ... Dustproof filter 11 ... Vacuum rotating part

Claims (1)

(57) [Scope of request for utility model registration] 1. A dustproof device for a vacuum chamber having a rotating part in which a shaft member penetrating a vacuum chamber and a vacuum chamber relatively rotate, wherein an O-ring is provided on an outer periphery of the shaft member, and A magnetic pole member having a concentric shape and provided in the longitudinal direction with a gap in the radial direction, a magnetic force generator sandwiched between the magnetic pole members, and filling a radial gap between the magnetic pole member and the shaft member A magnetic fluid sealing mechanism made of a magnetic material having fluidity is provided at a position closer to the inner wall side of the vacuum chamber than the O-ring, and a rotating portion between the magnetic fluid sealing mechanism and the O-ring and the inside of the vacuum chamber are disposed. A dustproof device for a vacuum chamber, comprising: a communication passage communicating with the filter; and a dustproof filter provided in the communication passage.