JPH0653086U - Dustproof device for vacuum chamber - Google Patents

Abstract

(57) [Abstract] [Purpose] A device for maintaining a desired vacuum state and a clean environment in a vacuum chamber, which is a low-cost vacuum because the relatively rotating rotary part has a short dimension in the major axis direction. To provide a dustproof device for a chamber. In a dustproof device for a vacuum chamber having a rotating portion in which a shaft member penetrating the vacuum chamber and the vacuum chamber rotate relative to each other, an O-ring is provided on the outer periphery of the shaft member, and the shaft member is coaxial with the shaft member. A magnetic pole member provided with a gap in the radial direction and separated in the major axis direction, a magnetic force generator sandwiched between the magnetic pole members, and fluidity filled in the gap between the magnetic pole member and the shaft member in the radial direction. A magnetic fluid sealing mechanism made of a magnetic material having a magnet is disposed on the inner wall side of the vacuum chamber with respect to the O-ring, and the rotating part between the magnetic fluid sealing mechanism and the O-ring is connected to the inside of the vacuum chamber. The passage is provided and a dustproof filter is provided in the communication passage.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a dustproof device for a vacuum chamber having a rotating member in which a shaft member penetrating the vacuum chamber and the vacuum chamber rotate relative to each other.

[0002]

[Prior art]

 For example, when the shaft member 2 is rotated with respect to the vacuum chamber 1 as shown in FIG. 1, it is necessary to maintain a desired vacuum state and a clean environment inside the vacuum chamber 1 with respect to the outside of the vacuum chamber 1. .

Conventionally, as shown in FIGS. 5 and 6, a magnet 5 is sandwiched between magnetic pole members 4A and 4B, and a radial gap between the magnetic pole members 4A and 4B and the magnetic shaft member 2 is provided. 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 magnet 5 to form the magnetic fluid seal mechanism 6. There is. The magnetic fluid seal mechanism 6 protects the rotating portion from dust and airtightness.

Although the restraining force of the magnetic body 3 serves as a vacuum holding capability, when the normal magnetic pole member 4 and the magnet 5 are used, the sealable pressure difference between the pair of magnetic fluid seal mechanisms 6 is limited. There is a limit, and in general, when maintaining a vacuum, the magnetic fluid seal mechanisms 6 are arranged in multiple stages.

[0005]

[Problems to be solved by the device]

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

Therefore, an object of the present invention is an apparatus for maintaining a desired vacuum state and a clean environment in a vacuum chamber having a rotating member in which a shaft member penetrating the vacuum chamber and the vacuum chamber rotate relative to each other. In addition, it is an object of the present invention to provide an inexpensive dustproof device for a vacuum chamber, in which the size of the relatively rotating rotary part is short in the long axis direction.

[0007]

[Means for Solving the Problems]

 INDUSTRIAL APPLICABILITY The present invention is applied to a vacuum chamber dustproof device having a rotating member in which a shaft member penetrating the vacuum chamber and the vacuum chamber rotate relatively. A characteristic of the magnetic pole member is that an O-ring is arranged on the outer periphery of the shaft member, the magnetic pole member is concentric with the shaft member, and is spaced apart in the major axis direction with a gap in the radial 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 of the vacuum chamber rather than the O-ring. Is provided on the side of the magnetic fluid sealing mechanism and the O ring, and a communication passage that connects the rotating portion 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 passage. That is.

[0008]

【Example】

 Hereinafter, the present invention will be described in detail with reference to illustrated embodiments. In FIG. 2, reference numerals 1 and 2 denote a vacuum chamber 1 and a shaft member 2 which rotate relative to each other, for example, the vacuum chamber 1 is fixed. The shaft member 2 has magnetism, is rotatably supported by the bearings 10 and 10 with respect to the vacuum chamber 1, and is rotated by a driving device (not shown). 4A and 4B are disk-shaped magnetic pole members arranged in the vacuum chamber 1, and a constant gap is formed between the inner peripheral surface of the magnetic pole member 4 and the outer peripheral surface of the shaft member 2. 3A and 3B are magnetic materials having fluidity, and 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 the magnetic force lines formed by the magnetic force generator 5, for example, a magnet. Be detained. The magnetic fluid seal mechanism 6 is composed of 3 to 5 as in the conventional case. Reference numeral 7 is an O-ring arranged on the outer periphery of the shaft member 2, 8 is a communication passage communicating the vacuum chamber 101 with the space 11 of the rotating portion, and 9 is a dustproof filter arranged in the communication passage 8. is there.

By the way, even when the shaft member 2 is rotated, since the O-ring 7 is disposed between the vacuum chamber 1 and the shaft member 2, the inside of the vacuum chamber 101 is maintained in a desired vacuum state. . When used for a long time, dust is generated due to friction between the O-ring 7 arranged on the shaft member 2 and the circumferential surface of the vacuum chamber 1 as the shaft member 2 rotates. Since the magnetic fluid sealing mechanism 6 and the dustproof filter 9 seal the interior of the vacuum chamber 101, a desired clean environment is maintained. Further, since the inside of the vacuum chamber 101 and the space 11 of the rotating portion are communicated with each other by the communication passage 8 so that the pressure difference is eliminated, the magnetic fluid sealing mechanism 6 only needs to protect the rotating portion from dust. The sealing mechanism 6 may be provided in the vacuum chamber 1 only once. As a result, the dimension in the long axis direction can be shortened. Further, since only one set of the magnetic fluid sealing mechanism 6 is used, the cost is low.

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

Further, FIG. 4 is a view showing a modification of FIG. 2, in which the communication passage 17 is arranged in the shaft member 2. According to this structure, the difficult processing of disposing the communication passage 8 in the vacuum chamber 1 becomes unnecessary.

[0012]

[Effect of device]

 As is clear from the above description, an O-ring is arranged at the rotating portion of the relatively rotating vacuum chamber and the shaft member, and the magnetic fluid sealing mechanism is arranged at a position closer to the inner wall of the vacuum chamber than the O-ring. In addition, a communication passage that connects the rotating portion between the magnetic fluid seal mechanism and the O-ring and the inside of the vacuum chamber is provided, and a dustproof filter is provided in the communication passage. The inside of the chamber is maintained in a desired vacuum state, and 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 passage, the magnetic fluid seal mechanism only needs to protect the rotating portion from dust, and only one stage needs to be provided in the vacuum chamber. As a result, the dimension in the major axis direction can be shortened, and since only one magnetic fluid sealing mechanism is used, it is inexpensive.

[Brief description of drawings]

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

FIG. 2 is a sectional view showing an essential part of the first embodiment of the present invention.

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

FIG. 4 is a sectional view showing a modified example of FIG.

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 ... Dust-proof filter 11 ... Vacuum rotation part

Claims (1)

[Scope of utility model registration request] 1. A dustproof device for a vacuum chamber having a rotating portion in which a shaft member penetrating the vacuum chamber and the vacuum chamber rotate relatively to each other, wherein an O-ring is provided on an outer periphery of the shaft member, The magnetic pole members are concentric and spaced apart in the major axis direction with a gap in the radial direction, a magnetic force generator sandwiched between the magnetic pole members, and the radial gap between the magnetic pole member and the shaft member is filled. A magnetic fluid sealing mechanism made of a magnetic material having fluidity is disposed at a position closer to the inner wall of the vacuum chamber than the O-ring, and the 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, in which a communication passage communicating with and a filter for dustproofing are provided in the communication passage.