JP2001020951A - Static pressure gas bearing - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a static pressure gas bearing without laying a piping in a space around a bearing by exhausting gas through an exhaust hole disposed on a bed in a forcible exhaust mechanism. SOLUTION: A moving body 1 is engaged with a fixing body 2 having a fine clearance. A fine clearance is formed between the moving body 1 and a level block 3 by pressure of air supplied from the level block 3, air to be supplied is passed an air supplying inner piping in a bottom plate 1a of the moving body 1, and is entered into the fine clearance between the moving body 1 and the fixing body 2, and the moving body 1 is moved in right and left directions in a non-contact condition. In a prior art, an exhaust piping 10 and an air supplying piping 11 are connected to the moving body 1 and the fixing body 2, and thereby, the freedom of an arrangement for various kinds of devices installed in a vacuum chamber is restricted. Accordingly, it is possible to improve the freedom of an arrangement for various kinds of devices installed in the vacuum chamber, since there is not necessity for laying the piping on the level block 3.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a hydrostatic gas bearing. More specifically, the present invention relates to a hydrostatic gas bearing that can be used in a vacuum.

[0002]

2. Description of the Related Art Hydrostatic gas bearings used in vacuum include:
Conventionally, exhaust piping and air supply piping have been directly connected to a moving body and / or a fixed body.

[0003]

However, the piping connected to the moving or fixed body is routed around the bearing in the vacuum chamber and occupies a large space. For this reason, the installation location of other devices disposed around the bearing is greatly restricted, and it has been difficult to design a semiconductor exposure apparatus or the like on which the bearing is mounted. The present invention has been made to solve the above problems, and an object of the present invention is to eliminate pipes directly connected to a moving body and a fixed body, and therefore, do not route pipes in a space around a bearing. It is to provide a hydrostatic gas bearing.

[0004]

Means for Solving the Problems To achieve the above object, the invention of claim 1 is provided on a surface plate, comprises a moving body and a fixed body, has a forced exhaust mechanism around the air pad, In the static pressure gas bearing usable in a vacuum, the forcible exhaust mechanism is connected to an exhaust hole provided in a surface plate, and gas is exhausted through the exhaust hole. An exhaust hole is provided in the surface plate on which the bearing is installed, and gas is exhausted through the exhaust hole, which eliminates the need to connect an exhaust pipe directly to the bearing, and the arrangement of various devices installed in the vacuum chamber is reduced. The degree of freedom can be increased.

[0005] The invention of claim 2 is characterized in that the exhaust hole provided in the surface plate is connected to a vacuum pump provided outside and / or inside the vacuum chamber. Since the exhaust hole provided in the surface plate is connected to a vacuum pump installed outside and / or inside the vacuum chamber, the exhaust of the forced exhaust mechanism performed through the exhaust hole provided in the surface plate is performed. A processing apparatus having a static pressure gas bearing that does not leak into the chamber can be provided.

According to a third aspect of the present invention, the supply of gas to the static pressure gas bearing is performed through an air supply hole provided in the surface plate. Like the exhaust pipe, the air supply pipe is also connected to the surface plate, and air is supplied to the bearing through an air supply hole provided in the surface plate. Thereby, the piping connected to the bearing can be omitted for the air supply piping. Further, the supply and exhaust of gas through the surface plate can be performed simultaneously.

[0007]

FIG. 1 is a perspective view showing an embodiment of a hydrostatic gas bearing installed in a chamber (not shown) according to the present invention. In the figure, a moving body 1 is engaged with a fixed body 2 with a small gap. Further, a minute gap is formed between the base plate 3 and the supply plate 3 by the pressure of the supply air supplied from the base plate 3, and the supplied supply air is supplied to the internal supply pipe 8 in the bottom plate 1 a of the moving body 1. (Described in FIG. 3)
The moving body 1 enters the minute gap between the moving body 1 and the fixed body 2 and
Is in a non-contact state and can move left and right. As for the exhaust, an exhaust pipe 10 connected to the back surface of the platen 3 through an exhaust hole 4 (shown in FIG. 2) provided on the surface of the platen 3.
More exhausted. Conventionally, the exhaust pipe 10 and the air supply pipe 11 are connected to the moving body 1 or the fixed body 2, and the degree of freedom of arrangement of various devices installed in the vacuum chamber has been restricted. In particular, when pipes are connected to the moving body 1, the pipes are drawn around by the movement of the moving body 1, so that the apparatus cannot be installed in that range. According to the present invention, since piping is not routed on the surface plate 3, the degree of freedom in the arrangement of various devices installed in the chamber can be increased.

FIG. 2 shows the lower surface of the bottom plate 1a of the moving body 1 and the exhaust hole 4 and the air supply hole 6 provided in the surface plate 3. The exhaust hole 4 on the surface plate 3 is provided at a position corresponding to the gas recovery groove 5 provided on the lower surface of the bottom plate 1a of the moving body 1. The gas recovery grooves 5 are provided double or triple around the air pad, and constitute a forced exhaust mechanism. As a result, the gas supplied from the air supply hole 6 on the surface plate 3 to the air supply groove 7 of the moving body 1 passes through the air supply internal pipe 8 provided in the bottom plate 1a and flows out of the air pad 9. , Gas recovery groove 5
And almost all of the gas is exhausted to the pump through the exhaust hole 4, so that the amount of gas flowing out of the bearing is suppressed to a very small amount, and the gas can be used in a vacuum.

FIG. 3 is a sectional view of an exhaust mechanism of the hydrostatic gas bearing according to this embodiment. As shown in the figure, since the exhaust internal pipe 12 is provided from the bottom plate 1a to the side plate 1b inside the moving body 1, the gas exhaust from the side plate 1b is the same as the gas exhaust from the bottom plate 1a. The same can be done.

FIG. 4 is a sectional view of an exhaust mechanism for a hydrostatic gas bearing according to the present embodiment. Air pad 9 shown in FIG.
Then, the air supplied from the air supply hole 6 (shown in FIG. 3) of the base plate 3 and having passed through the air supply groove 7 and the internal air supply pipe 8 provided in the bottom plate 1a of the moving body 1 blows out. The supply air blown into the minute gap has a high pressure, and the moving body 1 has a surface plate 3 and a fixed body 2.
And comes into a non-contact state. Since the balance in the vertical direction is achieved by the air pad 9 between the bottom plate 1a and the surface plate 3, and the air pad 9 between the bottom plate 1a and the fixed body 2, it is not necessary to provide the air pad 9 between the top plate 1c and the fixed body 2. The structure is simpler than the structure in which the air pad 9 and the air supply / exhaust groove are provided on all four inner surfaces of the body 1.

FIG. 5 shows a bottom plate 1 of a fixed body 1 according to this embodiment.
a, the air supply groove 7, the air pad 9, and the gas recovery groove 5
2 shows a detailed embodiment of the present invention. In the drawing, a gas supply groove 7 is provided at the center, two air pads 9 are provided on the left and right sides of the gas supply groove 7 in total, and a total of four air pads 9 are shown.

The preferred embodiment of the present invention has been described above.
The present invention is not limited to the shapes and arrangements shown in these examples.

[0013]

According to the present invention, the following effects are exhibited by the above configuration. According to the first aspect, an exhaust hole is provided in the surface plate on which the static pressure gas bearing is installed, and gas is exhausted through the exhaust hole, so that various devices can be arranged on the surface plate in the vacuum chamber. it can.

According to the second aspect, the exhaust hole provided in the surface plate is connected to a vacuum pump provided outside and / or inside the vacuum chamber. It is possible to provide a processing apparatus having a static pressure gas bearing in which the exhaust of the forced exhaust mechanism does not leak into the chamber.

In the third aspect, the air supply pipe is connected to the surface plate as well as the exhaust pipe, and air is supplied to the bearing through the air supply hole provided in the surface plate. The piping connected to the pressurized gas bearing can also be omitted for the air supply piping. Further, by simultaneously supplying and exhausting gas through the surface plate, all the pipes on the surface plate can be eliminated.

[Brief description of the drawings]

FIG. 1 is a perspective view illustrating an embodiment of a hydrostatic gas bearing mechanism according to the present invention.

FIG. 2 is a diagram showing a positional relationship between an exhaust hole provided on a surface plate and a gas recovery groove provided on a moving body in the static pressure gas bearing mechanism shown in FIG.

FIG. 3 is a sectional view of an exhaust mechanism of the hydrostatic gas bearing mechanism shown in FIG.

FIG. 4 is a sectional view of an air supply mechanism of the hydrostatic gas bearing mechanism shown in FIG.

FIG. 5 is a view showing an air supply groove, an air pad, and a forced exhaust mechanism of the static pressure gas bearing mechanism shown in FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Moving body 1a ... Bottom plate 1b ... Side plate 1c ... Top plate 2 ... Fixed body 3 ... Surface plate 4 ... Exhaust hole 5 ... Gas collection groove 6 ... Air supply hole 7 ... Air supply groove 8 ... Internal piping for air supply 9 ... Air pad 10 ... Exhaust pipe 11 ... Air supply pipe 12 ... Exhaust internal pipe

Claims (3)

[Claims] 1. A static pressure gas bearing installed on a surface plate, comprising a moving body and a fixed body, having a forced exhaust mechanism around an air pad, and capable of being used in a vacuum. A static pressure gas bearing connected to an exhaust hole provided in the gas turbine, and exhausting gas through the exhaust hole. 2. The hydrostatic gas bearing according to claim 1, wherein the exhaust hole provided in the surface plate is connected to a vacuum pump installed outside and / or inside the vacuum chamber. 3. The hydrostatic gas bearing according to claim 1, wherein the gas is supplied to the hydrostatic gas bearing through an air supply hole provided in the surface plate.